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ELEMENT IB10

WORK ENVIRONMENT RISK AND CONTROLS

NIST INSTITUTE PVT LTD

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ELEMENT IB10 – WORK ENVIRONMENT RISK AND CONTROL

IB10.1 The need for, and factors involved in, the provision and maintenance of temperature in both moderate and extreme thermal environments BODY HEAT BALANCE Ordinarily the body remains at a fairly constant temperature of 98.6°F. It is very important that this body temperature be maintained and, since there is a continuous heat gain from internal body processes, there must also be a continuous loss to maintain body heat in balance. Excess heat must be absorbed by the surrounding air or lost by radiation. As the temperature and humidity of the environment vary, the human body automatically regulates the amount of heat it gives off. However, the body’s ability to adjust to varying environmental conditions is limited. Furthermore, although the body may adjust to a certain (limited) range of atmospheric conditions, it does so with a distinct feeling of discomfort. The following discussion will help you understand how atmospheric conditions affect the body’s ability to maintain a heat balance. Body Heat Gains The human body gains heat (1) by radiation, (2) by convection, (3) by conduction, and (4) as a by-‐product of the physiological processes that take place within the body (for example, the conversion of food into energy). Heat gain from radiation comes from our surroundings. However, heat always travels from areas of higher temperature to areas of lower temperature. Therefore, the human body receives heat from those surroundings that have a temperature higher than body surface temperature. The greatest source of heat radiation is the sun. Some sources of indoor heat radiation are heating devices, operating machinery, and hot steam piping. Heat gain from conviction comes only from currents of heated air. Such currents of air may come from a galley stove or an operating diesel engine. Heat gain from conduction comes from objects with which the body comes in con-‐tact. Most body heat comes from within the body itself. Heat is produced continuously inside the body by the oxidation of food, by other chemical processes, and by friction and tension within muscle tissues. Body Heat Losses There are two types of body heat losses: loss of sensible heat and loss of latent heat. Sensible heat is given off by (1) radiation, (2) convection, and (3) conduction. Latent heat is given off by the breath and by evaporation of perspiration. WHAT IS THERMAL COMFORT? -‐ DEFINITION Thermal comfort is defined in British Standard BS EN ISO 7730 as: ‘That condition of mind which expresses satisfaction with the thermal environment.’ So the term ‘thermal comfort’ describes a person’s psychological state of mind and is usually referred to in terms of whether someone is feeling too hot or too cold. Thermal comfort is very difficult to define because you need to take into account a range of environmental and personal factors when deciding what will make people feel comfortable. These factors make up what is known as the ‘human thermal environment.' The best that you can realistically hope to achieve is a thermal environment that satisfies the majority of people in the workplace or put more simply, ‘reasonable comfort.'

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The UK HSE considers 80% of occupants as a reasonable limit for the minimum number of people who should be thermally comfortable in an environment. As a consequence, it can be seen that thermal comfort is not measured by air temperature, but by the number of employees complaining of thermal discomfort. To better understand why air temperature alone is not a valid indicator of thermal comfort, see the ‘six basic factors’ -‐ following. WHY IS THERMAL COMFORT IMPORTANT? People working in uncomfortably hot and cold environments are more likely to behave unsafely because their ability to make decisions and/or perform manual tasks deteriorates. For example; • People may take short cuts to get out of cold environments, or • Workers might not wear personal protective equipment properly in hot environments increasing the risks, or • The workers' ability to concentrate on a given task may start to drop off and increases the risk of errors

occurring. As an employer, you should be aware of these risks and make sure the underlying reasons for these behaviours are understood and taken into account. Addressing the underlying reasons for these behaviours is also likely to improve morale and productivity as well as improving health and safety. ADAPTING TO THE THERMAL ENVIRONMENT People employ adaptive strategies to cope with their thermal environment, e.g. donning or removing clothing, unconscious changes in posture, choice of heating, moving to cooler locations away from heat sources, etc. The problems arise when this choice (to remove the jacket, or move away from heat source) is removed, and people are no longer able to adapt. In many instances the environment within which people work is a product of the processes of the job they are doing, so they are unable to adapt to their environment. SIX BASIC FACTORS The most commonly used indicator of thermal comfort is air temperature -‐ it is easy to use, and most people can relate to it. But although it is an important indicator to take into account, air temperature alone is neither a valid nor an accurate indicator of thermal comfort or thermal stress. Air temperature should always be considered in relation to other environmental and personal factors. The six factors affecting thermal comfort are both environmental and personal. These factors may be independent of each other but together contribute to a worker’s thermal comfort. ENVIRONMENTAL FACTORS: • Air Temperature • Radiant Temperature • Air Velocity • Humidity

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PERSONAL FACTORS: • Clothing Insulation • Metabolic Heat

THE EFFECTS OF WORKING IN HIGH AND LOW TEMPERATURES AND HUMIDITY WORKING IN COLD CONDITIONS If the body's core temperature of 37°C is allowed to drop by no more than 4°C, serious problems can occur, potentially leading to death. With decreasing temperature the worker's performance decreases significantly. Manual dexterity suffers, both as a result of the loss of sensation to the fingers and also as a result of wearing gloves to combat the cold. Ultimately the person can suffer hypothermia where the body's core temperature drops from its normal level of 37°C to below 35°C. As a result of the effects of cold on the body, the worker's ability to move and lift items is also significantly impaired by a factor that must be taken into account in manual handling assessments. The extra stress caused by coping with the lowered working temperatures also reduces the worker's ability to concentrate, thus increasing the error rate. If hypothermia starts to set in, this level of impairment to thought processes becomes dramatically significant and can make any attempt to continue working dangerous and pointless. When working in cold conditions -‐ either inside or outdoors -‐ it is important that the worker is issued with the correct personal protective equipment appropriate to control the risks. In the most severe conditions, it will be necessary to cover the body, hands and face to avoid frostbite. However, in most cold conditions it is only necessary to ensure that the chilling effect of the wind and the extra cooling effects of wet clothes against the skin are avoided. To achieve suitable wind and waterproofing, it is necessary to repel exterior water -‐ such as rain -‐ and to remove dampness generated inside the wet weather gear from perspiration.

Source: hse.gov.uk Source: hse.gov.uk

Source: pinterest.com

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As a result, it may be necessary to issue wet or cold weather gear that will adequately control both the sources of dampness. It must be stressed that great care must be taken in restoring warmth to over-‐cooled workers as the effects of rubbing or sudden application of heat can cause serious injury. Anyone suspected of suffering from cold should be warmed slowly. If mild frostbite has occurred, the part affected (usually a hand or foot) should be dried and warmed slowly, perhaps by immersion in warm water then dabbed dry (do not rub). If the person is suffering from hypothermia, they should be removed from the cold and put into dry clothing or blankets -‐ no direct heat, such as hot-‐water bottles, should be used directly onto the person's skin. Warm drinks may be given if the person is conscious, but not alcohol. Where the effects of cold are severe, the affected person should receive medical attention.

Physiological Effects Work Examples Heat Stress

Skin Burns Cataracts Dehydration Heat Cramps Raised Heart Rate Headaches Confusion Vomiting Fainting

High air temperatures High levels of humidity Outside of working in hot climates

Cold Stress

Lowered Heart Rate Hypothermia Loss of Concentration Shivering Frost Bite Increased Risk of Strains and Sprains

Cold Stores Food Preparation Areas Outside of working in cold climates

HUMIDITY Humidity is a measure of water vapour in the surrounding air. Air can only hold so much water vapour, and the maximum is used as a relative measure to give a relative humidity (RH) out of 100%. Since the air can only carry a certain amount of water vapour, high levels of humidity -‐ usually in excess of 80% RH -‐ can seriously impede the evaporation of sweat, thus restricting the body's ability to lose heat.

Source: CSS

Source: ompaperconservation.com

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At the other end of the scale, low humidity -‐ usually below 30% RH -‐ can dry out mucous membranes, such as those of the throat and eyes, giving rise to soreness and a higher susceptibility to coughs and colds as a result of the loss of protection this causes. A side effect of low humidity levels in offices is a higher level of airborne dust than would otherwise be the case. This can exacerbate the health problems caused by the already compromised bodily defences, creating a greater risk of respiratory illness. Another side effect of low humidity is the increase in static electricity from carpets and furniture. This is unlikely to cause a serious hazard, but can cause great discomfort, both while working at a desk and also if the static discharges as a spark when touching metal objects, such as filing cabinets. A particular occupational issue from humidity arises with the use of personal protective equipment (PPE). Whether the PPE is waterproof or not, it will trap some air near the body (note that this is just as applicable to smaller items such as hats and gloves as it is to whole body clothing). The effect of trapping these small pockets of air is to create a 'micro-‐climate' at these points. The small pockets of air will saturate with water vapour and thus inhibit loss of heat locally. Thus, although the RH may be within reasonable limits outside the PPE, it could pose a serious risk to the health of the wearer through heat stress as a result of reduced ability to lose heat. The more all-‐encompassing and waterproof the PPE the worse will be the effect. WORK IN VERY HOT ENVIRONMENTS It is sometimes necessary to work in very hot environments, at least for short periods. In these circumstances, every effort must be made to cool the body and maintain the internal body temperature below 102°F (39°C). This can be achieved by the use of individual cooling fans, by wearing reflective garments which minimise the radiant heat load, air cooled suits or pocketed waistcoats containing ice packs. Workers should only enter hot environments for short periods (depending on the actual temperatures experienced) with long rest pauses between periods of exposure. The worker must be carefully monitored to ensure that he or she does not exceed safe exposure times. A good guide to the worker's physiological response is the pulse rate. This can be recorded after an initial short period of exposure with the time that the pulse rate takes to return to normal also being noted. Depending on pulse rate and recovery time, judgments may be made as to the length of the next period of exposure and of the rest period required between exposures. At very high temperatures, e.g. over 122°F (50°C), dry air may be tolerated in circumstances where any degree of humidity could result in skin burns of the respiratory tract. In general, it has to be said that work in very hot environments, over 113°F (45°C), requires the employment of experienced workers in circumstances where skilled and experienced physiological supervision is available. HEAT STRESS / SYNCOPE / STROKE A major hazard for the body at higher temperature is the adverse effect on physiological and biochemical processes.

Source: foundryservice.com

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HEAT STRESS Heat stress reflects the normal physiological response to work in a hot environment. Muscle work causes the body temperature to rise and is normally controlled by a number of cooling mechanisms. These include direct cooling by vasodilatation of blood vessels at the surface and by evaporative cooling -‐ perspiration. A major component of heat stress is dehydration when the loss of evaporative cooling exceeds the resources available to the body. It is compounded by humidity, high humidity adversely affecting the efficiency of evaporative cooling. As the body gets hotter the ability to think and react is compromised. This, in turn, can present additional hazards, including the undertaking of unsafe actions. Cramping of muscles may also occur -‐ mostly due to the loss of essential ions through the sweating process coupled with the redirection of blood supply to the skin. HEAT SYNCOPE Heat syncope (heat exhaustion) -‐ occurs when the circulation is unable to cope with the impact of heat generated by metabolic processes (work) and the environment. Syncope (fainting) occurs as the body diverts blood to the periphery in an attempt to respond to the increased cooling required. HEAT STROKE Heat stroke-‐ is a potentially fatal condition. It represents a complete breakdown in the protective mechanisms for dealing with heat. Sweating ceases, and the metabolic heat (core body temperature) dramatically increases with loss of consciousness. The body appears cold and 'clammy' although the core temperature is dangerously high. The following table shows heat exposure limits in terms of the relatively simple effective temperature assessment.

Effective Temperature. Heat exposure limits suggested for personnel, not in direct sunlight Maximum Effective Temperature in degrees Fahrenheit

and Centigrade Exposure time Rest or Sedentary Moderate Work Heavy Work Continuous daily work 87 / 30.5 84 / 29 79 / 26 Intermittent work-‐rest 3 hours 91 / 33 86 / 30 82 / 28 2 hours 92 / 33 88 / 31 84 / 29 1 hour 95 / 35 91 / 33 87 / 30.5 30 minutes 101 / 38 96 / 35.5 91 / 33 20 minutes 105 / 40.5 100 / 38 95 / 35

Source: CSS

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TYPICAL WORK SITUATIONS LIKELY TO LEAD TO THERMAL DISCOMFORT WHO MAY BE AFFECTED Workers in a variety of jobs can be exposed to extremes of thermal discomfort, being excessively hot or alternatively excessively cold, Occupations would include those working out of doors – winter and or summer, day and or night when temperature swings can be considerable. Outdoor workers who have to endure extreme weather temperatures include those more easy to identify such as those involved in construction, road maintenance (including snow clearing and rescue) and others who do not always come readily to mind such as life-‐guards, etc. Those working in occupations such as foundries and bakeries, smelting plants, glass production plants endure quite extraordinary high temperatures, these being further exaggerated by their locations in some hot climate countries. On the other extreme end of the scale, we have workers who are employed in cold stores, ice making plants and those working in other cold, well below freezing indoor conditions e.g. ice or snow parks and resorts. All of the above occupation factors can, of course, be further complicated when humidity levels are taken into consideration. Working in hot and cold conditions, as well as the effects of humidity, is covered in more detail elsewhere in this element. THE ENVIRONMENTAL PARAMETERS AFFECTING THERMAL COMFORT ENVIRONMENTAL FACTORS/PARAMETERS AIR TEMPERATURE This is the temperature of the air surrounding the body. It is usually given in degrees Celsius (°C) or degrees Fahrenheit (°F). RADIANT TEMPERATURE Thermal radiation is the heat that radiates from a warm object. Radiant heat may be present if there are heat sources in an environment. Radiant temperature has a greater influence than air temperature on how we lose or gain heat to the environment. Our skin absorbs almost as much radiant energy as a matt black object, although this may be reduced by wearing reflective clothing. Examples of radiant heat sources include the sun; fire; electric fires; furnaces; steam rollers; ovens; walls in kilns; cookers; dryers; hot surfaces and machinery, molten metals, etc. AIR VELOCITY This describes the speed of air moving across the worker and may help cool the worker if it is cooler than the environment.

Source: jorlandoabantoquevedo.blogspot.com

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Air velocity is an important factor in thermal comfort because people are sensitive to it. Still or stagnant air in indoor environments that are artificially heated may cause people to feel stuffy. It may also lead to a build-‐up in odour. Moving air in warm or humid conditions can increase heat loss through convection without any change in air temperature. Small air movement in cool or cold environments may be perceived as a draught. If the air temperature is less than skin temperature, it will significantly increase convective heat loss. Physical activity also increases air movement, so air velocity may be corrected to account for a person's level of physical activity. HUMIDITY If water is heated and it evaporates to the surrounding environment, the resulting amount of water in the air will provide humidity. Relative humidity is the ratio between the actual amount of water vapour in the air and the maximum amount of water vapour that the air can hold at that air temperature. Relative humidity between 40% and 70% does not have a major impact on thermal comfort. In some offices, humidity is usually kept between 40-‐70% because of computers. However, in workplaces which are not air conditioned, or where the climatic conditions outdoors may influence the indoor thermal environment, relative humidity may be higher than 70% on warm or hot humid days. Humidity in indoor environments can vary greatly, and may be dependent on whether there are drying processes (paper mills, laundry, etc.) where steam is given off. High humidity environments have a lot of vapour in the air, which prevents the evaporation of sweat from the skin. In hot environments, humidity is important because less sweat evaporates when humidity is high (80%+). The evaporation of sweat is the main method of heat loss in humans. When vapour-‐impermeable PPE is worn, the humidity inside the garment increases as the wearer sweats because the sweat cannot evaporate. If an employee is wearing this type of PPE (e.g. asbestos or chemical protection suits etc.) the humidity within the microclimate of the garment may be high. THE ENVIRONMENTAL PARAMETERS AFFECTING THERMAL COMFORT -‐ HOW TO MEASURE THEM

ASPECTS AFFECTING THERMAL COMFORT Thermal comfort is not due solely to temperature. It is a combination of a number of factors including: • Ambient temperature, which should not vary excessively • Level of activity and thus the metabolic rate of the individual • Amount of radiant heat (sunlight or from hot processes), which should normally be

maintained within 3°C of the ambient temperature • The amount of insulation provided by the clothing worn

• Air movement, which should be less than 0.3 m/sec • Humidity -‐ the relative humidity should be between 40% and 60% These factors are often combined to give a qualitative indication of the likely effect of the thermal environment on the worker.

Source: kids.britannica.com

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A reasonable indication of temperature is given by adding the measured air (ambient) temperature to the mean radiant temperature and halving the result, i.e. the mean of the two Temperatures. Resultant Temperature = (Tamb + Trad)/2 Where Tamb is the ambient air temperature Trad is the mean radiant temperature (also known as the 'black globe' temperature) This resultant temperature should usually be between 19°C and 23°C to ensure the comfort of sedentary workers. A worker's ability to cope with extremes of temperature can be assisted by acclimatisation. However, this process should not be undertaken lightly and never without medical advice on the ability of the person to undertake it. Under normal working conditions, it is much more preferable to provide external or engineering means to assist the normal worker to cope with the thermal environment than to expect the worker to adapt to it. THERMOMETERS DRY BULB The dry-‐bulb temperature is the temperature of air measured by a thermometer freely exposed to the air but shielded from radiation and moisture. Dry bulb temperature is the temperature that is usually thought of as air temperature, and it is the true thermodynamic temperature. It is the temperature measured by a regular thermometer exposed to the airstream. Unlike wet bulb temperature, dry bulb temperature does not indicate the amount of moisture in the air. In construction, it is an important consideration when designing a building for a certain climate. WET BULB This wet bulb thermometer is a traditional way of measuring humidity. The simple unit is made up of two glass thermometers, which are very easy to read.

One is attached to a small synthetic water container and a wick, and the relative humidity is calculated by reading both thermometers, then using a chart that is provided with the thermometer to calculate the humidity. It may seem like there are many new and more efficient ways to calculate humidity than this, but despite technological advances, this is still one of the most accurate and reliable ways to get a good reading.

With a little practice, you will soon find that it is actually very easy to operate.

GLOBE APPLICATIONS For use by heating and ventilating engineers, factory inspectors, medical health officers, and others concerned with the environmental health conditions in factories, offices, hospitals, and laboratories, etc.

Source: kwalitytraders.tradeindia.com

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In some environmental conditions, for example in factories where hot processes are carried out, it is necessary to measure the mean temperature of solid surroundings when attempting to control or improve working conditions. This information will show whether excessive radiant heat is reaching workers. Conversely, such measurements would also show whether cold surroundings are causing undue heat loss by radiation from the human body. PRINCIPLE OF OPERATION A hollow metal globe coated on the outside with matt-‐black paint absorbs the radiant heat from surrounding objects so that, after a time lag, the temperature at the centre of the globe is a measure of the radiant heat and not of the air surrounding it. A temperature sensor inserted into the globe measures this temperature. Insert the glass thermometer into the rubber stopper and position the thermometer bulb in the centre of the globe. Soapy water may be used to lubricate the thermometer when inserting and removing it from the rubber stopper. Assemble the mounting stand and suspend the thermometer and globe as shown in the manufacturer’s instructions. Place the instrument in position, without any objects between the heat source and the globe. Avoid placing the instrument where relatively large air currents are expected. Wait for at least 15 or 20 minutes before taking an observation. The difference between the temperature of the globe and the temperature outside the globe is called the actual radiant temperature. The mean radiant temperature (MRT) can be calculated using the globe thermometer’s temperature using the following formula: art (°C) = tg + 2.42V (tg -‐ ta) V: air current cm/sec ta: temperature of the air outside of the globe tg: globe thermometer temperature Radiation (R) can be estimated using the following formula: R = 0.173/10-‐8 (MRT)4 Btu/ft2h MRT: MRT + 460 Btu: British Thermal Unit, a unit of heat defined as the amount of heat required to raise one pound of water one degree Fahrenheit at one atmosphere pressure, equivalent to approximately 252 calories KATA A kata thermometer measures the cooling power of the environment; it is used to estimate the personal comfort of workers (see also "heat stress monitor" and "personal temperature monitor"). A spirit-‐in-‐glass thermometer is usually used: its bulb is heated to above body temperature, removed from the heat source and allowed to cool. The time taken for the thermometer reading to drop from above to below normal body temperature (e.g., from 38 °C to 35 °C) is used to calculate the cooling power of the atmosphere, using a calibration factor F engraved on the thermometer by the manufacturer: cooling power = F/(time of cooling).

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ANEMOMETERS An anemometer is a device for measuring wind speed and is a common weather station instrument. The term is derived from the Greek word anemos, meaning the wind, and is used to describe any airspeed measurement instrument used in meteorology or aerodynamics. Anemometers can be divided into two classes: those that measure the wind's speed, and those that measure the wind's pressure; but as there is a close connection between the pressure and the speed, an anemometer designed for one will give information about both. One type of anemometer is a hot-‐wire anemometer. The hot-‐wire anemometer measures the wind speed based on variations in temperature or electric resistance of a metal wire. As the wind speed increases, more energy is used to keep the metal wire at a pre-‐set temperature. Wind speed is determined by measuring the electrical consumption of the wire. This device is not typically used for official National Weather Service wind measurement. Another type of anemometer and probably more familiar type is a rotation anemometer. This device measures wind speed based on the rotation of a sensing element such as a propeller or spinning cups. As wind speed increases the anemometer will rotate faster. Portable versions of this anemometer are also available. Different anemometers will have different calibrations. For instance, a current of 1mA might mean 1m/s, or it might mean 1cm/s, depends on the internal setup of the meter. Any meter you use should have some kind of calibration markings or documents with it. PSYCHROMETERS (WET AND DRY BULB THERMOMETER) A psychrometer is an instrument commonly used in laboratories to measure relative humidity. It is also referred to as a wet-‐ and dry-‐bulb thermometer. This instrument consists of two similar thermometers that are mounted side by side. • The dry bulb has its bulb exposed to the air. • The wet bulb is wrapped in an absorbent material such as muslin, which is immersed in water and serves as a

wick. When the web bulb is taken out of the water, it cools by evaporation of the water. If the bulb is whirled around to hasten evaporation, it is called a sling psychrometer. If air is forced past the bulb, it is referred to as an aspirated or ventilated psychrometer. The amount of evaporation, and consequent cooling of the thermometer depends on the humidity of the atmosphere -‐ the drier the atmosphere, the faster the water evaporates. Using this data and humidity tables or calculations, the dew point (the temperature to which air would have to be cooled for saturation to occur) can be determined, and from it, the relative humidity. INTEGRATED ELECTRONIC INSTRUMENTS INCLUDING HEAT STRESS MONITORS In all Thermal Environment Monitors a dry bulb sensor measures ambient temperature; a wet bulb sensor takes into account evaporative cooling, giving an indication of the effects of humidity on an individual; and a globe sensor provides an indication of the radiant heat exposure on an individual due to either direct light or hot objects in an environment. Thermal Environment Monitors convert these measurements to a simplified, single-‐number Indoor and Outdoor WBGT Index. This index can then be used in conjunction with guidelines developed by ACGIH, U.S. Navy, EPRI, ISO, and others.

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Each of these guidelines includes considerations for real-‐life variables such as activity levels or clothing types worn. Some advanced models of Thermal Environment Monitors also compute Humidex. Humidex is another form of a heat stress index used in Canada in accordance with guidelines such as those defined by the Occupational Health Clinics for Ontario Workers-‐Hamilton (OHCOW). Using Thermal Environment Monitors in conjunction with any one of these guidelines enables you to determine appropriate work/rest regimens or stay times for workers in situations where heat stress is a life safety and liability risk. Area heat stress monitors are very valuable for their ability to provide simultaneous protection to groups of workers with a single instrument. The compromise present in area heat stress measurements is that each worker is in reality physiologically unique. Environmental conditions and physical activity that cause heat stress for one worker may not affect another while conditions that do not affect one worker may affect another. The guidelines that exist for stay times and work/rest regimens based on measured WBGT values are generalized to represent the expected impact of given environmental conditions and physical activity on groups of individuals. The results of the WBGT method can include unnecessarily shortened work times for some workers and insufficient protection of others. This is why experts insist that monitoring is used only in conjunction with worker observation and monitoring for heat stress symptoms. OTHER PARAMETERS AFFECTING THERMAL COMFORT PERSONAL FACTORS/PARAMETERS CLOTHING INSULATION Clothing, by its very nature, interferes with our ability to lose heat to the environment. Thermal comfort is very much dependent on the insulating effect of clothing on the wearer. Wearing too much clothing or personal protective equipment (PPE) may be a primary cause of heat stress even if the environment is not considered warm or hot. If clothing does not provide enough insulation, the wearer may be at risk from cold injuries such as frostbite or hypothermia in cold conditions. Clothing is both a potential cause of thermal discomfort as well as a control for it as we adapt to the climate in which we live and play. You may add layers of clothing if you feel cold, or remove layers of clothing if you feel warm. However, many companies remove this ability for their employees to make reasonable adaptations to their clothing. It is important to identify how the clothing may contribute to thermal comfort or discomfort. It may also be necessary to evaluate the level of protection that any PPE is providing – can less or other PPE be used? WORK RATE/METABOLIC HEAT The work or metabolic rate is essential for a thermal risk assessment. It describes the heat that we produce inside our bodies as we carry out physical activity. The more physical work we do, the more heat we produce. The more heat we produce, the more heat needs to be lost, so we don’t overheat. The impact of metabolic rate on thermal comfort is critical. When considering these factors, it is also essential to consider a person's own physical characteristics. A person's physical characteristics should always be borne in mind when considering their thermal comfort, as factors such as their size and weight, age, fitness level and sex can all have an impact on how they feel, even if other factors such as air temperature, humidity, and air velocity are all constant.

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SWEAT RATE AND DURATION OF EXPOSURE A measure of the amount of sweat produced per unit time. One formula for calculating the sweat rate of an athlete is: sweating rate = (pre-‐exercise body weight − post-‐exercise body weight + fluid intake − urine volume)/exercise time (h). Weight is measured in kilograms and volumes in millilitres. It is assumed that during the relatively short period of exercise, weight changes are due to water loss. As 1000 ml of water weighs 1 kg, sweat production can be calculated in units of millilitres of sweat produced per hour. During prolonged work periods in the heat (8–12-‐hour shifts), the maintenance of high sweat rates leads to progressive dehydration, which may be accompanied by impairment of mental and physical performance and of heat dissipation. Dehydration will impair work capacity and may pose a serious risk to health; the intake of fluid during the working period to replace sweat losses is, therefore, imperative. However, the sodium replacement need is often overlooked, mainly as a consequence of scant information regarding the sweat loss of sodium over time. There is also little information available concerning the variability of sweat concentration from different regions of the body (is sweat sodium the same in all body regions) and between the same individual (un-‐acclimatised and acclimatised). With a better understanding of electrolyte loss in sweat, accurate advice regarding replacement beverages can be provided to workers performing manual tasks in the heat. Commercially prepared sports drinks have varying concentrations of glucose and sodium, and range from hypertonic to hypotonic with respect to the plasma. Sodium is added to some drinks for the purpose of replacing sweat salt losses, and to aid in the transport of glucose across the intestinal wall. Glucose is added to the drinks in order to maintain blood glucose levels (avoid fatigue) during the work period. Sweat is hypotonic to plasma and to some of the electrolyte replacement drinks available. Consequently, the consumption of these electrolyte replacement drinks, if made available to workers ad libitum, may result in the consumption of too much sodium. On the other hand, if sweat losses are replaced with plain water a dilution of the plasma may occur to the point of the person being hyponatremic. It should be emphasized that sweat losses can exceed 1.5 litres/hour when working in very hot environmental conditions. Meal breaks in order to allow salt and glucose intake from solid food are a must if workers are using water to replace sweat loss as nearly all food contain some sodium. However before appropriate sodium intake can be recommended, the loss over a work duration must be known. Soft drinks and cordials have approximately 10% sugar content, and if these are used as a sole replacement beverage, this can significantly increase the daily kilojoule intake of the worker. During the summer when sweat rates are high, it is not uncommon for some workers to consume 10 litres of fluids in the working day. The daily sugar intake in this instance would be over 1.0 kg. In addition, cola and recently released "designer drinks" have a moderate to high concentration of caffeine. This can reduce fluid retention. Coffee and to a lesser extent tea are also caffeinated beverages, and large consumption (more than two cups per work shift) should be avoided especially during the summer when sweat rates can be high. Some drinks have a low pH (acidic) and high sugar concentration (10%), and while they may be appropriate for short duration sports sweat replacement, they should not be recommended for daily high volume consumption.

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Thus, workers require education so that appropriate choices are made about replacement fluids. This is particularly true at the beginning of summer when they are un-‐acclimatised to the heat; however we do not currently have a comprehensive understanding of sweat sodium losses in workers. As sweat loss can be up to10 to 12 litres per day, and sweat contains sodium, an essential electrolyte, the above notes was designed to better understand sweat sodium loss so that informed educational strategies can be put in place in order to prevent heat illness and accidents due to the effects of heat strain in the workplace.

CONCLUSION Based on the results of the above study the following conclusions and recommendations are provided: • People working in moderately hot conditions for 10 hours on average will lose between 4.8 and 6 g of sodium

(Na) equivalent to 12–15 g of salt (NaCl) depending on acclimatisation. However due to the substantial inter-‐individual variation in sweat rate and sodium concentration, individual losses may be much higher. This essential electrolyte must be replaced in order to avoid fluid imbalances, thus eating during the shift is a must.

• One work session in the heat, for an acclimatised person, is sufficient to activate sodium-‐conserving mechanisms. However in the unacclimatised worker, longer exposure is required. A worker starting work in harsh conditions should be given 10 days or more to acclimatise before performing heavy manual work in the heat.

• Cordials and sports drinks are contra-‐indicated for people working in hot environments due to the very high energy content. An ideal fluid replacement beverage for industrial use should have significant sodium content with minimum carbohydrate.

HEAT BALANCE EQUATION M= K±C±R±E For the internal body temperature to be maintained at around 37°C, there must be an equilibrium between the amount of heat generated within the body and the heat transferred to or from it. This equilibrium, or balance, is by no means constant but is as dynamic as the conditions within which the body is working. The concept of the heat balance equation for the human body explains and provides an understanding of how 37°C internal body temperature is maintained. Parsons (1993) points out that all heat balance equations have the same underlying concept: heat generation within the body, heat transfer, heat storage. The equations below show the conceptual heat balance equation: Where metabolic rate (M) provides energy enabling the body to perform mechanical work (W). The remainder of the energy is given off as heat (M-‐W). There are a number of ways that heat transfer can be achieved: evaporation (E), radiation (R), convection (C) and conduction (K). The resultant heat production and loss provide the storage (S), wherein heat balance, S = zero. M -‐ W = E + R + C + K + S When S=0 M -‐ W -‐ E -‐ R -‐ C -‐ K = 0 MEASURING THERMAL COMFORT USING PREDICTED MEAN VOTE (PMV) AND PERCENTAGE PEOPLE DISSATISFIED (PPD) INDEX AND USE OF ISO 7730 AND ISO 10551 STANDARDS

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PREDICTED MEAN VOTE (PMV) INDEX The PMV index predicts the mean response of a larger group of people according to the ASHRAE thermal sensation scale where +3 hot +2 warm +1 slightly warm 0 neutral -‐1 slightly cool -‐2 cool -‐3 cold The PMV index is expressed by P.O. Fanger as PMV = (0.303 e-‐0.036M + 0.028) L (1) Where, PMV = Predicted Mean Vote Index M = metabolic rate L = thermal load -‐ defined as the difference between the internal heat production and the heat loss to the actual environment -‐ for a person at comfort skin temperature and evaporative heat loss by sweating at the actual activity level PREDICTED PERCENTAGE DISSATISFIED (PPD) INDEX Predicted Percentage Dissatisfied -‐ PPD -‐ the index is a quantitative measure of the thermal comfort of a group of people at a particular thermal environment. Note -‐ at least approx. 5% of people in a group will be dissatisfied with the thermal climate -‐ even with PMV = 0 PMV-‐PPD PMV represents the 'predicted mean vote' (on the thermal sensation scale) of a large population of people exposed to a certain environment. PMV is derived from the physics of heat transfer combined with an empirical fit to the sensation. PMV establishes a thermal strain based on steady-‐state heat transfer between the body and the environment and assigns a comforting vote to that amount of strain. PPD is the predicted percent of dissatisfied people at each PMV. As PMV changes away from zero in either the positive or negative direction, PPD increases. The PMV equation for thermal comfort is a steady-‐state model. It is an empirical equation for predicting the mean vote on an ordinal category rating scale of thermal comfort of a population of people. The equation uses a steady-‐state heat balance for the human body and postulates a link between the deviation from the minimum load on heat balance effector mechanisms, e,g, sweating, vasoconstriction, vasodilation, and thermal comfort vote. The greater the load, the more the comfort vote deviates from zero. The partial derivative of the load function is estimated by exposing enough people to enough different conditions to fit a curve. PMV (Predicted Mean Vote), as the integrated partial derivative is now known, is arguably the most widely used thermal comfort index today. The ISO (International Standards Organization) Standard 7730 (ISO 1984),

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"Moderate Thermal Environments -‐ Determination of the PMV and PPD Indices and Specification of the Conditions for Thermal Comfort," uses limits on PMV as an explicit definition of the comfort zone. The PMV equation only applies to humans exposed for a long period of constant conditions at a constant metabolic rate. Conservation of energy leads to the heat balance equation: H-‐Ed-‐Esw-‐Ere-‐L=R+C Where: H = internal heat production Ed = heat loss due to water vapour diffusion through the skin SW = heat loss due to sweating Ere = latent heat loss due to respiration L = dry respiration heat loss R = heat loss by radiation from the surface of the clothed body C = heat loss by convection from the surface of the clothed body The equation is expanded by substituting each component with a function derivable from basic physics. All of the functions have measurable values with the exception of clothing surface temperature and the convective heat transfer coefficient which are functions of each other. To solve the equation, an initial value of clothing temperature is estimated; the convective heat transfer coefficient computed, a new clothing temperature calculated, etc., by iteration until both are known to a satisfactory degree. Now let us assume the body is not in balance and write the heat equation as: L = H-‐Ed-‐Esw-‐Ere-‐L-‐R-‐C, Where L is the thermal load on the body. Define thermal strain or sensation, Y, as some unknown function of L and metabolic rate. Holding all variables constant except air temperature and metabolic rate, we use mean votes from climate chamber experiments to write Y as a function of air temperature for several activity levels. Then substituting L for air temperature, determined from the heat balance equation above, evaluate the partial derivative of Y with respect to L at Y=0 and plot the points versus metabolic rate. An exponential curve is fit to the points and integrated with respect to L. L is simply renamed "PMV", and we have (in simplified form): PMV = exp[met]*L. Where: L=F(Pa,Ta,Tmrt,Tcl) PMV is "scaled" to predict thermal sensation votes on a seven-‐point scale (hot, warm, slightly warm, neutral, slightly cool, cool, cold) by virtue of the fact that for each physical condition, Y is the mean vote of all subjects exposed to that condition. The major limitation of the PMV model is the explicit constraint of skin temperature and evaporative heat loss to values for comfort and "neutral" sensation at a given activity level. THE ASSESSMENT OF HEAT STRESS, ROLE OF HEAT INDICES

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INTRODUCTION Many attempts have been made over the years to develop an index which, through a single figure, is able to provide an indication of the risk of heat stress. However, a thermal index has yet to be developed which can accurately predict a person’s physiological strain to all environments. There is a growing body of opinion that computer modelling provides the best solution to the prevention of heat stress. Belding provides the following recommendations to anyone who is “so bold as to improve on existing standards”: • One of the major problems seems to be the establishment of criteria which are representative of

physiological stress and strain; • To accurately predict the level of strain in such a way as to provide a practical application; • The “ultimate index should provide a means for rating time-‐limited exposures”; • The use of sweat rate is only really justified in terms of dehydration levels and salt depletion; • Mean skin temperature is the result of the effects of environment and metabolic heat loads on the

circulatory efficiency of the blood and the evaporative cooling effectiveness. A heat stress index is a model of human thermoregulation. Models (and indices) are, by their very nature, limited in their functionality and as such the model (whether it be a graphical or numeric representation, mathematical equations) will never be a perfect representation. Therefore, when investigating models, errors or deviations from the observed are expected, but the performance criteria are not so much how accurate it is, but rather whether or not these inaccuracies are significant in terms of the application or situation to which it is intended to be applied. This is very much the case in Human Modelling because there is such a wide variation between individuals in their physiological responses. This is still further complicated by the fact that much of our knowledge of human responses to thermal environments is incomplete. This, however, by no means negates the potential that human modelling has in the development of research methods and practical applications to address human responses to thermal environments. TYPES OF HEAT STRESS INDICES There are generally three types of methods used for the assessment of hot environments: EMPIRICAL Data from laboratory studies provided data that makes it possible to predict the likely effects an environment will have on a human, (i.e. Physiological responses); DIRECT Standardised measuring instruments are used to measure environmental parameters such as globe temperature. RATIONAL Calculations of the heat exchanges between the human and the environment provide a method to predict the human responses. These methods all have the same criteria in common, in that their purpose is to define or establish the physiological responses of humans to their environment.

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The figure that follows shows a simplification of the method of calculating climatic indices, which results in a simplified value or combined measure which can represent the large possible combinations of the parameters that make up the human thermal environment. A diagrammatic representation of calculating climatic indices as described by Eissing (1995) According to Eissing (1995), this simple index value allows for a simple comparison between environments, different working situations and different clothing ensembles to be made. EFFECTIVE TEMPERATURE (ET) AND CORRECTED EFFECTIVE TEMPERATURE (CET) The Effective Temperature (ET) scales were originally devised by Houghton and Yaglogou in 1923 as comfort indices and, in 1927, Yaglou realised that it would be a good physiological index of stress (Leithead and Lind, 1964). ET takes wet bulb temperature, dry bulb temperature, and air velocity into account but does not take into account radiant heat. Bedford in 1946 proposed the replacement of an air temperature measured with the use of globe temperature to provide a measure of radiant heat. This produced the Corrected Effective Temperature (CET). The CET has been used extensively in the coal mines in the UK. THE HEAT STRESS INDEX (HSI) The Heat Stress Index (HSI), was developed by Belding and Hatch (1955) as an analytical index that provides an expression on a scale of 0 to 100 that represents heat stress and hence heat strain and thereby the amount of time a worker can be exposed to a hot environment. There is a table (see the following table) that provides the equations used in the calculation of HSI and the resultant Allowable Exposure Times (AET).

CLOTHED UNCLOTHED Radiation Loss (W.m-‐2) R=k1(35-‐t1) For k1=4.4 7.3 Convection Loss (W.m-‐2) C=k2v0.6(35-‐ta) For k2=4.6 7.6 Emax (W.m-‐2) Emax=k3v0.6(56-‐ta)

(Upper limit of 390 W.m-‐2

For k3=7.0 11.7

Ereq (W.m-‐2) Ereq=M-‐R-‐C Heat Stress Index HIS =(Ereq/

Emax)x100

Allowable Exposure Time AET = 2440 (Ereq -‐ Emax) mins

Source: CSS

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Equations used in the calculation of the (HSI) and Allowable Exposure Times (AET), (from Parsons, 1993) In addition a further table provides an interpretation of the HSI values – see the following table. The table above shows the equations for the Heat Stress Index, which is based on a comparison of Ereq and Emax. Although it is derived independently, the HSI value is related to the required skin wetness (wreq) value (which is derived from Ereq/Emax). As such, it describes strain in terms of sweating, and because it multiplies the wreq value by a 100, it describes a prescriptive zone between 0 and 100 (see the next table). When a value is obtained that is greater than 100, an AET is produced because it effectively means that a skin wetness value greater than that capable of being produced (remember it is related to wreq) is required.

HIS VALUE EFFECT ON 8 HOUR EXPOSURE -‐20 Mild cold strain (e.g. recovery from heat exposure) 0 No thermal strain 10 – 30 Mild to moderate heat strain – Little effect on physical work but possible effect on

skill 40 – 60 Severe heat strain, involving threat to health unless physically fit – Acclimation

required 70 – 90 Very severe heat strain -‐ Personnel should be selected by medical examination,

adequate water and salt intake must be ensured. 100 Maximum strain tolerated daily by fit acclimatised young men. Over 100 Exposure time limited by a rise in deep body temperature.

FIRST AID Take the following steps to treat a worker with heat stroke: • Call 999 and notify their supervisor. • Move the sick worker to a cool, shaded area. • Cool the worker using methods such as:

- Soaking their clothes with water. - Spraying, sponging or showering them with water. - Fanning their body.

HEAT EXHAUSTION Heat exhaustion is the body's response to an excessive loss of the water and salt, usually through excessive sweating.

Source: CSS

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Workers most prone to heat exhaustion are those that are elderly, have high blood pressure, and those working in a hot environment. SYMPTOMS Symptoms of heat exhaustion include: • Heavy sweating • Extreme weakness or fatigue • Dizziness, confusion • Nausea • Clammy, moist skin • Pale or flushed complexion • Muscle cramps • Slightly elevated body temperature • Fast and shallow breathing FIRST AID Treat a worker suffering from heat exhaustion with the following: • Have them rest in a cool, shaded or air-‐conditioned area. • Have them drink plenty of water or other cool, nonalcoholic beverages. • Have them take a cool shower, bath, or sponge bath.

HEAT SYNCOPE Heat syncope is a fainting (syncope) episode or dizziness that usually occurs with prolonged standing or sudden rising from a sitting or lying position. Factors that may contribute to heat syncope include dehydration and lack of acclimatization. SYMPTOMS Symptoms of heat syncope include: • Light-‐headedness • Dizziness • Fainting FIRST AID Workers with heat syncope should: • Sit or lie down in a cool place when they begin to feel symptoms. • Slowly drink water, clear juice, or a sports beverage.

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HEAT CRAMPS Heat cramps usually affect workers who sweat a lot during strenuous activity. This sweating depletes the body's salt and moisture levels. Low salt levels in muscles cause painful cramps. Heat cramps may also be a symptom of heat exhaustion. SYMPTOMS Muscle pain or spasms usually in the abdomen, arms, or legs. FIRST AID Workers with heat cramps should: • Stop all activity, and sit in a cool place. • Drink clear juice or a sports beverage. • Do not return to strenuous work for a few hours after the cramps subside because further exertion may lead

to heat exhaustion or heat stroke. • Seek medical attention if any of the following apply:

- The worker has heart problems. - The worker is on a low-‐sodium diet. - The cramps do not subside within one hour.

HEAT RASH Heat rash is a skin irritation caused by excessive sweating during hot, humid weather. SYMPTOMS Symptoms of heat rash include: • Heat rash looks like a red cluster of pimples or small blisters. • It is more likely to occur on the neck and upper chest, in the groin, under the breasts, and in elbow creases. FIRST AID Workers experiencing heat rash should: • Try to work in a cooler, less humid environment when possible. • Keep the affected area dry. • Dusting powder may be used to increase comfort. RECOMMENDATIONS FOR EMPLOYERS Employers should take the following steps to protect workers from heat stress: • Schedule maintenance and repair jobs in hot areas for cooler months. • Schedule hot jobs for the cooler part of the day. • Acclimatize workers by exposing them for progressively longer periods to hot work environments. • Reduce the physical demands of workers. • Use relief workers or assign extra workers for physically demanding jobs. • Provide cool water or liquids to workers.

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- Avoid alcohol, and drinks with large amounts of caffeine or sugar. • Provide rest periods with water breaks. • Provide cool areas for use during break periods. • Monitor workers who are at risk of heat stress. • Provide heat stress training that includes information about:

- Worker risk - Prevention - Symptoms - The importance of monitoring yourself and coworkers for symptoms - Treatment - Personal protective equipment

RECOMMENDATIONS FOR WORKERS Workers should avoid exposure to extreme heat, sun exposure, and high humidity when possible. When these exposures cannot be avoided, workers should take the following steps to prevent heat stress: • Wear light-‐colored, loose-‐fitting, breathable clothing such as cotton.

- Avoid non-‐breathing synthetic clothing. • Gradually build up to heavy work. • Schedule heavy work during the coolest parts of the day. • Take more breaks in extreme heat and humidity.

- Take breaks in the shade or a cool area when possible. • Drink water frequently. Drink enough water that you never become thirsty. Approximately 1 cup every 15 -‐

20 minutes. • Avoid alcohol, and drinks with large amounts of caffeine or sugar. • Be aware that protective clothing or personal protective equipment may increase the risk of heat stress. • Monitor your physical condition and that of your coworkers. ACCLIMATISATION WHAT IS HEAT ACCLIMATIZATION? Heat acclimatization refers to biological adaptations that reduce physiologic strain (e.g., heart rate and body temperature), improve physical work capabilities, improve comfort and protects vital organs (brain, liver, kidneys, muscles) from heat injury. The most important biological adaptation from heat acclimatization is an earlier and greater sweating response, and for this response to improve it needs to be invoked. Heat acclimatization is specific to the climate and physical activity level. Those who only perform light or brief physical work will achieve the level of heat acclimatization needed to perform that task. If they attempt a more strenuous or prolonged task, additional acclimatization and improved physical fitness will be needed to successfully perform that task in the heat.

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HOW DO YOU BECOME HEAT ACCLIMATIZED? Heat acclimatization occurs when repeated heat exposures are sufficiently stressful to elevate body temperature and provoke perfuse sweating. Resting in the heat, with limited physical activity to that required for existence, results in only partial acclimatization. Physical exercise in the heat is required to achieve optimal heat acclimatization for that exercise intensity in a given hot environment. Generally, about two weeks of daily heat exposure is needed to induce heat acclimatization. Heat acclimatization requires a minimum daily heat exposure of about two hours (can be broken into two 1-‐hour exposures) combined with physical exercise that requires cardiovascular endurance, (for example, marching or jogging) rather than strength training (push-‐ups and resistance training). Gradually increase the exercise intensity or duration each day. Work up to an appropriate physical training schedule adapted to the required physical activity level for the advanced military training and environment. The benefits of heat acclimatization will be retained for ~1 week and then decay with about 75 percent lost by ~3 weeks, once heat exposure ends. A day or two of intervening cool weather will not interfere with acclimatization to hot weather. PRACTICAL CONTROL MEASURES TO MINIMISE THE RISKS WHEN WORKING IN EXTREME THERMAL ENVIRONMENT CONTROLLING THERMAL COMFORT There are a number of ways that you can manage thermal comfort in the workplace: ADMINISTRATIVE CONTROLS Administrative controls include planning and rescheduling work times and practices and rest schedules, for example, scheduling ‘hot’ work for cooler times of the day or giving workers flexible hours to help avoid the worst effects of working in high temperatures. Administrative controls are generally of a short-‐term, temporary nature and are also widely recognised as being more expensive and less cost-‐effective than engineering controls in the long-‐term. ENGINEERING CONTROLS These should be the first choice to reduce or eliminate the hazard. Although the initial cost of engineering controls seems high, it has been found that the implementation cost is often offset by the resulting improvements in production and decrease in downtime, with reduced absenteeism and improved motivation. It is important to stress that any practical solution to controlling thermal comfort is likely to require a combination of different options alongside consultation between employers, employees, and their representatives. HEATING

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Many types of heating systems are available: • Hot air based heating systems; • Water based central heating systems using radiators; • Combined heat and ventilation systems using air conditioning systems; • Electrical heating systems using electrical heaters; • Under-‐floor heating systems using either electrical coils or heated fluids; • Overhead heating systems. Most of these systems are useful. However, the beneficial effects may be in some situations restricted to the immediate locality of the heat source. AIR MOVEMENT There are many methods for increasing air movement. Small ‘personal’ fans can provide a refreshing movement of air on the face. Larger oscillating fans can provide a swirling air movement, though some people may find this draughty. There may also be noise problems. Large diameter fans suspended from the ceiling can provide a swirling air movement that is effective over a wide area. Exhaust fans, mounted on the roofs and walls, are useful for removing heated air; however, while improving general air movement, they may have little effect on thermal comfort. AIR CONDITIONING This can range from small units that lower the air temperature but do not control humidity levels or air movement, to large units that can cope with extreme conditions as well as humidity and air movement. When air conditioning systems are used, care should be taken to ensure uniform air distribution throughout the workplace. Otherwise some workers may complain of feeling cold while others are feeling hot. Air conditioning units should be operated as per the manufacturer’s instructions. EVAPORATIVE COOLING Evaporative coolers produce a moderate reduction in air temperature and increase humidity. They operate by passing hot air over water-‐saturated pads, and the water evaporation effect reduces the air temperature. THERMAL INSULATION There are many different types of thermal insulation materials, e.g. loose fills, rock wool, and boards. The material acts as a barrier, which slows heat flow in the summer and heat loss in the winter, but it is only effective where there is a temperature difference between the inside and the outside of the building or between two areas inside a building. GENERIC CONTROL MEASURES There are eight main methods of control which you can use: CONTROL THE HEAT SOURCE

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• Don't only consider this in relation to air temperature. • Reduce/increase temperature, humidity, radiant heat load or air movement. • Insulate the source of heat or cold. CONTROL THE ENVIRONMENT PARAMETERS • Replace hot air with cold, or replace cold air with hot, as required. • Humidify or dehumidify the air as required. • Increase air movement by ventilation or air conditioning. • Reduce draught discomfort by directing the ventilation or air movement so that it doesn't blow directly onto

the workers. SEPARATE THE SOURCE OF HEAT OR COLD FROM THE WORKER – WORKPLACE DESIGN • Erect barriers, shield the work area or restrict access. • Redesign jobs to remove the worker from the area. CONTROL THE TASK – JOB DESIGN • Restrict the length of time that workers are exposed to hot or cold conditions. • Control the amount of work that workers are expected to do. • Introduce mechanical aids to aid physically demanding jobs in warm and hot environments or when workers

are wearing a lot of clothing. CONTROL THE CLOTHING/PPE • If PPE is worn, make sure that workers are not wearing more PPE than is required (i.e., a higher protection

factor than is needed). • If uniforms are worn, evaluate alternative designs, new materials, etc. to improve wearability of clothing. • Evaluate dress code and allow workers to adapt their clothing where possible. • Multiple layers of clothing enable workers to make reasonable adjustments to their clothing based on their

own subjective feelings. ALLOW FOR THE WORKER TO MAKE BEHAVIOURAL ADAPTATIONS • Where possible, remove all restrictions that may prevent employees from making minor adjustments to their

clothing or work rate. • Provide warm-‐up or cool-‐down areas. • Provide personal heaters or fans. • Allow workers to adjust thermostats or open windows as appropriate. PROTECT THE WORKER • Provide suitable special clothing and/or equipment (e.g. desk fans). • Provide training. MONITOR THE WORKER INCLUDING HEALTH SURVEILLANCE • Provide appropriate supervision. • Obtain medical advice for workers who are pregnant, have an illness or disability or are on medication.

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• As required undertake a specific risk assessment for pregnant workers to identify and manage any risks. TRAINING Measurements by themselves cannot guarantee worker protection from heat stress. It is essential that workers learn to recognize the early signs and symptoms of heat stress and know how to prevent them!. If it’s possible, workers need to be able to alter their pace of work, take rest breaks, and drink in response to early symptoms (a cup of water every 20 minutes). The ideal heat stress response plan would let workers regulate their own pace by “listening” to their bodies. BRITISH, EUROPEAN, AND INTERNATIONAL STANDARDS RELEVANT TO WORKING IN THERMAL ENVIRONMENTS The following standards may be useful to course delegates when assessing thermal issues in the workplace. • BS EN ISO 9888:2001 Evaluation of thermal strain by physiological measurements • BS EN 28996 Ergonomics of the thermal environment – Estimation of metabolic heat production • BS EN 27243 Hot environments – Estimation of heat stress on a working man, based on the WBGT – Index

(Wet Bulb Globe Temperature) • BS 7915 Ergonomics of the thermal environment – Guide to design and evaluation of working practices in

cold indoor environments • ISO 11079 IREQ Evaluation of cold environments – Determination of required clothing insulation (IREQ) • BS EN 7730 Moderate thermal environments – Determination of the PMV and PPD indices and specification

of the conditions for thermal comfort • ISO 10551 Ergonomics of the thermal environment – assessment of the influence of the thermal environment

using subjective judgement scales • BS EN ISO 12894 Ergonomics of the thermal environment – Medical supervision of individuals exposed to

extreme hot or cold environments • BS 12515 ISO 7933 Hot environments – Analytical determination and interpretation of thermal stress using

the calculation of required sweat rate. • BS 7963 Ergonomics of the thermal environment – Guide to the assessment of heat strain in workers wearing

personal protective equipment • BS EN 27726 Thermal environments – Instruments and methods for measuring physical quantities • BS EN 14058 Protective clothing garments for protection against cool environments • BS ISO 15265 Ergonomics of the thermal environment – Risk assessment strategy for the prevention of stress

and discomfort in thermal working conditions • BS EN 511 Specification for protective gloves against cold • ISO 13732-‐3 Ergonomics of the thermal environment – Touching of cold surfaces Part 3. Ergonomics data and

guidance for application • BS EN 563 Safety of machinery – Temperatures of touchable surfaces – Ergonomics data to establish

temperature limit values for hot surfaces • ISO 11399 Ergonomics of the thermal environment – Principles and application of relevant international

standards

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• BS ISO 9920 Ergonomics of the thermal environment – Estimation of the thermal insulation and evaporative resistance of a clothing ensemble

ISO 15743 Ergonomics of the thermal environment -‐ cold workplaces -‐ risk assessment and management

IB10.2 Adequate and appropriate lighting in the workplace, the units of measurement of light and the assessment of lighting levels in the workplace THE NECESSITY FOR LIGHTING IN WORKPLACES WHY IS GOOD LIGHTING AT WORK IMPORTANT? Lighting at work is very important to the health and safety of everyone using the workplace. The quicker and easier it is to see a hazard, the more easily it is avoided. The types of hazard present at work, therefore, determine the lighting requirements for safe operation. Poor lighting can not only affect the health of people at work causing symptoms like eye strain, migraine, and headaches, but it is also linked to Sick Building Syndrome in new and refurbished buildings. Symptoms of this include: • Headaches, • Lethargy, • Irritability and • Poor concentration. COSTS OF POOR LIGHTING TO BUSINESS Poor lighting at work can represent a significant cost to business in the form of: • Time off work as a result of accidents and injuries; • Increased absenteeism; • Reduced staff efficiency and productivity. WHO IS RESPONSIBLE FOR LIGHTING AT WORK AND WHAT ARE THEIR LEGAL RESPONSIBILITIES? Under most National legislation employers, the self-‐employed and people in control of non-‐domestic premises have a duty to ensure that lighting is safe and does not pose a health risk to employees and others who may use their premises. Employers are also required to consult their employees on health and safety matters. Where safety representatives have been appointed by a recognised trade union, it is part of their function to advice during the consultation process. Where employees are not covered by trade union-‐appointed safety representatives, employers should consult employees directly or via representatives elected for this purpose. ADEQUATE AND APPROPRIATE LIGHTING AND LEVELS FOR THE WORK; NATURAL AND ARTIFICIAL LIGHTING For good lighting practice it is essential that, in addition to the required illuminance, other qualitative and quantitative needs are satisfied. Lighting requirements are determined by the satisfaction of three basic human needs:

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• Visual comfort, where the workers have a feeling of well-‐being; in an indirect way also contributing to a high productivity level,

• Visual performance, where the workers are able to perform their visual tasks, even under difficult circumstances and during longer periods,

• Safety. Main parameters determining the luminous environment are: • Luminance distribution, • Illuminance, • Glare, • Directionality of light, • Colour rendering and colour appearance of the light, • Flicker. Whilst the provision of natural lighting takes precedence over artificial lighting, in practice both will be required. Artificial lighting should be adequate and properly maintained for the safety and health of persons at work. To maximise the use of natural lighting, windows, skylights and glass partitions used for lighting workrooms should be kept clean on both inner and outer surfaces. The lighting levels should be sufficient to enable persons to detect obvious hazards as well as being able to work without experiencing eyestrain. Lighting arrangements should be made so that brightness, unsuitable shading or poorly placed light sources or workstations cannot cause discomfort or injury from glare or from the reflection of light into the eyes of the employees. Determining what is good and correct lighting depends on the visual demands of the task to be performed and the nature of the work to be performed, i.e. office work, hospital work, inspection of minute work (jewellery and watch-‐making), fine bench and machine work, rough bench work, etc. Standards set by recognised professional bodies, such as CIBSE, should be referred to as regards determining the correct level of lighting. Lights and light fittings should be of a type, and so positioned, that they do not cause a hazard (including electrical, fire or collision hazards). Glare and dazzle should be avoided. Light switches should be positioned for easy access and use without risk. Lights should not be allowed to become obscured, for example by stacked goods or appliances, in such a way that the light level is inadequate. In some cases, extra physical protection of light sources may be necessary to prevent the possibility of electrocution where there is a risk of physical impact, e.g. if located in pits or areas where metal tubing is being handled. THE IMPACT OF LIGHTING LEVELS ON SAFETY ISSUES INADEQUATELY LIT AREAS Poorly lit areas can lead to accidents, especially between pedestrians and vehicles because drivers do not see pedestrians clearly. This can also be the case if pedestrians are working in shadowy areas. Lighting should be good enough for people to work, use facilities and move about safely and without experiencing eye strain. Exposure to fluorescent lighting is associated with headaches, eye strain, eye irritation, fatigue and increased stress and accidents. Exposure is also associated with the onset of skin conditions, and

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there is growing evidence of a link with skin cancer. Some people become allergic to fluorescent lighting and more sensitive to sunlight. Flickering lighting may produce hyperactivity. POOR POSITIONING OF LIGHT SOURCES Where lights are positioned is important, i.e. lights placed in the centre of loading bays may be blocked by tall vehicles. If drivers have to reverse towards strong lights, the lights can dazzle the driver, either directly or via mirrors. CHANGE IN LIGHT LEVELS Sudden changes in lighting levels, such as when moving too quickly from bright to darker areas (from a dark warehouse to bright sunshine or from a dark night to a strongly lit building), make it hard to see. It can also make CCTV systems less effective as they can take the time to adjust to different lighting levels. Glare from the sun can sometimes be a problem for drivers. LACK OF NATURAL LIGHT A shortage of natural light can lead to seasonal affective disorder (SAD), resulting in a range of mental and physical illnesses. DIRTY OR OBSCURED LIGHTS Lights may be frequently obscured due to where they are positioned, e.g. tall vehicles may block a light source. Lights may also be dirty, from mud or dust, which will make them less bright and create dimly lit areas. STROBOSCOPIC EFFECTS Lamps that operate from an alternating electrical supply may produce oscillations in light output. When the magnitude of these oscillations is great, machinery will appear to be stationary or move in a different manner. This is called the stroboscopic effect. It is not common with modern lighting systems, but where it does occur it can be dangerous; so appropriate action should be taken to avoid it. FLICKER Light modulation at lower frequencies (about 50 Hz or less) which is visible to most people, is called flicker. The eye is particularly sensitive to flicker, and it is especially detectable at the edges of the visual system’s field of view. Flicker can, depending on individual sensitivity, be a source of both discomfort and fatigue. It may even cause epileptic seizures in some people. Therefore, it needs to be avoided. COLOUR EFFECTS A surface lit by different artificial light sources, or by daylight under changing sky conditions, may appear to vary in colour. Where colour discrimination is required (as for some electrical work), this can affect safety, but with most light sources the change in colour appearance is insufficient to create problems. Under monochromatic light sources, such as low-‐pressure sodium discharge lamps, colours will not be identifiable, and a hazard may go unnoticed. At very low illuminances, colour vision fails, and all colours are seen as shades of grey.

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The section on lighting recommendations in this guide suggests lighting levels which will prevent this effect. HUMAN FACTORS The lighting in your workplace should enable employees to comfortably see what they need to do their tasks. Poor lighting makes it hard for employees to see and can lead to visual fatigue and discomfort. It can also lead to neck and back pain if the worker adopts a poor posture (for example, if he or she constantly leans forward to see the work). Insufficient lighting also creates a dreary environment. Proper lighting, on the other hand, creates a pleasant atmosphere and gives workers a sense of well-‐being. This improves their productivity and efficiency. Lighting levels should meet the needs of older workers and workers with visual limitations. The ability to detect detail, for example, weakens with age. To compensate for this loss, increase the lighting to a comfortable level. One way to do this is by providing lighting with adjustable intensity. It also helps to increase the viewing time and the brightness of the workpiece. Older workers are also less able to focus on objects at different viewing distances. Employees who work with video display units/terminals (VDU/Ts) are most affected by this loss; they may need prescription glasses and more light. Older workers also take longer to adapt to changes in light intensity and are more sensitive to glare. To reduce these problems, control light and glare levels. EFFECTS OF BRIGHTNESS CONTRAST –TISSUE DAMAGE FROM LIGHT EXPOSURE, VISUAL FATIGUE DISABLING AND DISCOMFORT GLARE Glare occurs when one part of the visual field is much brighter than the average brightness to which the visual system is adapted. When there is a direct interference with the vision the condition is known as disability glare. Where vision is not directly impaired but there is discomfort, annoyance, irritability or distraction the condition is called discomfort glare. The latter is related to symptoms of visual fatigue. Both types of glare can arise from the same source. VEILING REFLECTIONS Veiling reflections are high luminance reflections which overlay the detail of the task. Such reflections may be sharp-‐edged or vague in outline, but regardless of the form they can affect task performance and cause discomfort. RADIATION Optical radiation can be harmful if too much enters the eye or falls on unprotected skin. Most people are well aware of the sunburn and skin cancer risks associated with too much exposure to the sun’s damaging ultraviolet rays. It is also important to understand that the visible emissions from the sun would damage our sight if we forced ourselves to stare at it for an extended period. VISIBLE RADIATION Like the sun, optical radiation emitted by manufactured lighting equipment is predominantly at visible wavelengths. Consequently, it is very difficult to overexpose people because they will automatically look away when dazzled by an excessively bright source. The radiation from most lighting equipment is therefore quite safe, and employers will not need to complete an assessment of radiation output.

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However, there are a few exceptions, the most important of which are listed below. INFRARED AND ULTRAVIOLET RADIATION Some lamp designs also produce significant emissions at infrared and ultraviolet wavelengths, both of which are invisible; employees could, therefore, be exposed to hazards without knowing it and would also not be able to avoid exposure. Some of the lamps and applications that need special consideration are listed below. PROBLEM SOURCES The lamps and lighting applications listed below are capable of causing excessive personal exposure in some circumstances, and it is, therefore, important that employers properly assess the risks and take appropriate safety measures. Manufacturers and suppliers should also provide adequate health and safety information to users to enable lamps to be used safely. In particular, it is important to specify any personal protective equipment needs, for example, eye protection. • Tungsten halogen lamps used in office desktop and close range spotlight applications. These operate at high

temperatures and may emit significant amounts of ultraviolet radiation which can be harmful to the skin and cornea of the eye when they are used close to people (i.e. within a metre or so) for extended periods. The luminaires in which these lamps are used should be fitted with an ultraviolet filter which should be checked periodically and replaced if damaged. If the luminaire has no filter, it should not be used for close-‐work applications.

• High-‐intensity discharge lamps, carbon arc and short-‐arc lamps These also emit significant amounts of ultraviolet radiation, usually at levels that exceed those from tungsten halogen lamps. However, like tungsten halogen designs, they should be fitted with a safety shield or ultraviolet filter as part of the lamp’s glass envelope. Safety shields should be replaced immediately if damaged.

High-‐power lamps used in theatres, broadcasting studios and entertainment These applications require very high output lighting for filming and performance work. Often the level of illumination required exceeds that of a bright summer’s day and the very high-‐power lamps that are used can be so bright that they are capable of damaging eyesight before people can avert their eyes. These lamps can also emit high levels of infrared and ultraviolet radiation. Manufacturers and suppliers must ensure that their products can be used without exposing people above relevant internationally accepted personal exposure limits and, where user precautions are necessary, that appropriate health and safety information is given to the user. This information should include maintenance requirements, user precautions, user training and personal protective equipment requirements. Users should ensure that the necessary health and safety information is obtained from the supplier and that it is followed. • Display lasers Some entertainment applications employ lasers to create lighting effects. HSE guidance The radiation safety of lasers used for display purposes3 gives comprehensive information on the radiation safety of these applications.

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TISSUE DAMAGE FROM LIGHT EXPOSURE BRIGHT LIGHT EXPOSURE RISKS -‐ CAUTIONARY NOTES ABOUT BRIGHT LIGHT EXPOSURE Light energy can interact with and damage skin and eye tissues, especially when a photosensitizing molecule – whether from a drug or produced by the body – is bound within those tissues. The highest risk (for damage to the skin, and cornea and lens of the eyes) is from invisible, short-‐wavelength ultraviolet (UV) light, which has been filtered out of CET’s recommended light therapy system. Long-‐term exposure to intense visible light in the blue range adjacent to the UV range may also pose a hazard to retinal photoreceptors and the pigment epithelium, which takes part in the photoreceptor renewal process. Above age 50, there is concern about the blue-‐light exacerbation of age-‐related macular degeneration. Although some blue is an important component of white light exposure, lamps with relatively less blue (for example, soft-‐white fluorescents with color temperatures in the range of 3000-‐4000 Kelvin) should be favored over cool white, daylight, or “full spectrum” lamps (5000 Kelvin and higher). PRE-‐EXISTING MEDICAL CONDITIONS MAY ENHANCE EXPOSURE RISKS There are certain pre-‐existing medical conditions of eyes and skin (retinal dystrophies, age-‐related macular degeneration, porphyria, lupus erythematosus, chronic actinic dermatitis and solar urticaria) that also can show photosensitized reactions to intense visible light. In such cases, bright light therapy should be administered only under the guidance of an ophthalmologist or dermatologist, as indicated. Ophthalmologists should keep in mind that in some genetic retinal diseases the eyes are especially light sensitive. MEDICATIONS & ENHANCED EXPOSURE RISKS Certain medications are known to photosensitize skin and/or retinal tissues. Examples in the visible range of light include psychiatric neuroleptic drugs (e.g., phenothiazine), psoralen drugs, antiarrhythmic drugs (e.g., amiodarone), antimalarial and antirheumatic drugs, porphyrin drugs used in the photodynamic treatment of skin diseases, and St. John’s Wort (hypericum). Bright light therapy should not be used concurrently with these drugs. Melatonin can be used in conjunction with light therapy at opposite times of day (usually, evening and morning, respectively), but if used concurrently, it can cause photosensitization. Drugs that photosensitizer primarily in the invisible UVA range (just below the blue range) may also have a “tail” of light absorption that extends into the lower visible blue light range, which could cause photosensitization. Examples are tetracycline, diuretic drugs (e.g., hydrochlorothiazide), sulfonamide drugs and tricyclic antidepressants (e.g., imipramine, nortriptyline, desipramine, amitriptyline). If such a reaction is experienced or suspected, bright light therapy should be discontinued unless substitute medication is available, or it can be administered with protective measures under medical supervision. IN CONCLUSION For the practice of bright light therapy, we must, therefore, consider the wavelength range of the light (and with that, its energy range) and the absorbing tissues in the eye. For normal healthy eyes, the exposure to bright white light is a physiological situation and does not inflict any overt damage to the skin, visual cells, and pigment epithelium. There are, however, certain important caveats: Medications that can enter the skin or retina and

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that absorb light in the visible range. This might cause photosensitization with the subsequent absorption of “too many photons,” leading to damage. If you want to use bright light therapy but are questioning your medication, consult an ophthalmologist or dermatologist. Certain inherited dystrophies of the retina that alter the visual pigments and can render the retina especially sensitive to visible light. If you suffer from an inherited retinal dystrophy and want to use bright light therapy, consult an ophthalmologist. Age-‐related or other macular degenerations. Forage–related macular degeneration, genetic factors increase the risk of disease by about 50%. Patients with such risk factors, or those with several family members suffering macular degeneration, should consult an ophthalmologist before using bright light therapy. Young eyes up to an age of about 30–40 years transmit much more light to the retina than older eyes. Thus, young eyes receive generally higher light doses than older ones. SOURCES Vincent DeLeo, M.D., St. Luke’s-‐Roosevelt Medical Center, New York; Charlotte Remé, M.D., University of Zurich, Switzerland. VISUAL FATIGUE Just like the muscles in your body, your eyes can get tired. For the job they do, your eyes contain the strongest muscles in your body. But as strong as they are, they can become strained and fatigued by sitting in front of a computer, under fluorescent lights or in front of a TV for a couple of hours. This is called visual fatigue. WHY CARE ABOUT VISUAL FATIGUE? Today, more and more people are suffering from visual fatigue without knowing the cause of their symptoms. Modern work and lifestyle changes have forced us to spend extended hours in close-‐range activities such as computer work, e-‐books, and hand-‐held gaming. The increased demands of these activities on your eyes can leave you with uncomfortable and sometimes painful symptoms. For some people, visual fatigue can also lead to a reduction in productivity and ability to concentrate—and may even negatively impact your vision health. COMMON SYMPTOMS • Headaches • Tired Eyes • Neck or Back pain • Burning / Stinging eyes • Difficulty focusing on extended periods of time If you are experiencing any of these symptoms, your eye doctor may be able to help. INSTRUMENTATION, UNITS AND MEASUREMENT OF LIGHT, ASSESSMENT OF LIGHTING LEVELS AND STANDARDS

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INSTRUMENTS FOR MEASURING LIGHT LEVELS USE OF LIGHT MEASURING INSTRUMENTS The human eye is unreliable as an indicator of how much light is present. For accurate results in the measurement of the illuminance at a surface, it is necessary to use a reliable instrument. Light meters are available for this purpose. A light meter, normally adequate for most locations, is a photocell which response to light falling on it by generating a small electric current which deflects a pointer on a graduated scale measured in lux or, more commonly nowadays, causes a number to be displayed on a digital display. Most light meters have a correction factor built into their design to allow for using a filter when measuring different types of light (daylight, tubular fluorescent lamps, high-‐pressure sodium lamps, etc.). The recommended procedure for taking measurements with a light meter of this type is to: • Cover the cell with opaque material and alter the zero adjustments until the pointer reads zero on the scale. • Allow a few minutes for the instrument to ‘settle down’ before taking a reading. • A longer period will be required if the light is provided by tubular fluorescent lamps or high-‐pressure

discharge lamps which have only just been switched on as they take the time to reach full light output. • Select the appropriate scale on the instrument, i.e. that which gives the greatest deflection of the pointer or

where the reading is closest to the upper end of the range. If readings are to be taken during daylight two readings are necessary: With the lights on and with the window blinds drawn back so as to record the combined effect of natural and artificial light, and With the same natural light conditions as in (a) but with the artificial lights switched off. The result required, i.e. the measure of the artificial light, is the difference between the two readings. If the two readings are large and approximately equal, it will be necessary to re-‐check the artificial light reading after dark. The measured illuminance should be checked against the maintained illuminance for the location and task, taking account of the requirements, laid down by the CIBSE for the relevant areas. The correct use of a light meter is an important aid to establishing good levels of lighting. However, to ensure accurate readings, the instrument should be kept in its case when not in use and away from damp and excessive heat. It is also advisable to have the calibration checked by the manufacturer every year, though this is not cheap and it may be more cost-‐effective to buy a new meter annually. Do not overestimate the accuracy of the readings you obtain. Few handheld meters are capable of measuring illuminance more accurately than within 10%, and the position of measurement can affect the measurement considerably. It is possible for measurements to differ from calculations by up to 60% for direct illumination and 20% for calculations involving inter-‐reflections. For maximum accuracy, measure at points on a regular grid through space and average the results. Accuracy will be particularly suspect at low levels even if the meter itself has various ranges. UNITS AND MEASUREMENT OF LIGHT There are many different units for measuring light and it can get very complicated. Here are a few common measurement terms CANDELA (CD) Unit of luminous intensity of a light source in a specific direction. Also called candle.

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Technically, the radiation intensity in a perpendicular direction of a surface of 1/600000 square metre of a black body at the temperature of solidification platinum under a pressure of 101,325 newtons per square metre. FOOTCANDLE (FC OR FTC) Unit of light intensity, measured in lumens per square foot. The brightness of one candle at a distance of one foot. Approximately 10.7639 lux. LUMEN (LM) Unit of light flow or luminous flux. The output of artificial lights can be measured in lumens. LUX (LX) Unit of illumination equals to one lumen per square meter. The metric equivalent of foot-‐candles (one lux equals 0.0929 foot-‐candles). Also called meter-‐candle MINIMUM LIGHTING LEVELS Lighting should be sufficient to enable people to work, use facilities and move from place to place safely and without experiencing eyestrain. There are minimum standards normally set out in National legislation e.g. the UK HSE guidance (see table below), but these are set at very low levels. If people have difficulty doing their job because the lighting is too dim then it may not be ‘suitable or sufficient’ and as such could be challenged. Below is a table that has been reproduced from HSE document HSG38 (Lighting at Work). It gives the recommended minimum lighting levels for different types of work activity and location.

Activity Typical Location Average Illuminance (lux)

Minimum Illuminance (lux)

Movement of people, machines and vehicles.

Lorry park, corridors, circulation routes. 20 5

Movement of people, machines and vehicles in hazardous areas; rough work is not requiring any perception of detail.

Construction site clearance, excavation and soil work, loading bays, bottling and canning plants.

50 20

Work requiring limited perception of detail.

Kitchens, factories assembling large components, potteries. 100 50

Work requiring the perception of detail.

Offices, sheet metal work, book binding. 200 100

Work requiring the perception of fine detail.

Drawing offices, factories assembling electronic components, textile production.

500 200

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Light intensity is measured in ‘Lux’. This can be a difficult scale to understand. The table below gives you some idea of how light intensity can vary in different situations.

Illuminance Example 1 lux Full moon overhead 50 lux Family living room 80 lux Hallway/toilet 100 lux Very dark overcast day 400 lux Sunrise or sunset on a clear day. Well lit office area 1000 lux Overcast day, typical TV studio lighting 10,000-‐25000 lux Full daylight (not direct sun) 32,000-‐130,000 lux Direct sunlight

It should be noted that these recommendations are for guidance only and that each location/activity needs to be considered individually. Also, if an area measured falls outside these levels, it does not necessarily mean that the lighting system in that whole area needs to be modified. Other measures such as task-‐specific lighting or use of desk lamps might be easier. The finer the detail, the higher the illuminance required. On the other hand, light that is too bright or glare that shines into your eyes can also cause problems. Glare from the light shining directly into the eye or reflecting from work surfaces should be controlled. Workers who move between brightly lit and dimly lit areas may also be at risk because it takes a few moments for the eyes to adjust to the different light levels, so it is important to try to ensure there is not an abrupt change, for example between a yard and a warehouse.

IB10.3 Welfare facilities and arrangements in fixed and temporary workplaces Welfare facilities and arrangements in fixed and temporary workplace INTRODUCTION International and national legislation and guidance contain all the requirements on issues such as toilets, washing facilities, locker and rest rooms, eating facilities, etc. The aim being to ensure that workplaces meet the basic welfare (as well as health and safety) needs of all the members of the workforce including people with disabilities. There are other regulations which contain more detailed requirements where the risk of contamination is high, where hazardous substances such as lead, asbestos, and ionising radiation are being handled.

Source: CSS

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PROVISION OF TOILETS, WASH-‐HAND BASINS, SHOWER & WASHING FACILITIES ‘Sanitary conveniences’ are flushing water closets (WCs) and urinals connected to an effective drainage system. A ‘washing facility’ is a wash hand basin (WHB), a shower or a bath with a hot and cold water supply and connected to a drainage outlet. Sanitary conveniences and washing facilities shall be provided at readily accessible places for all employees. This means that everyone at work can use them without delay.

NUMBERS OF WASHING ETC FACILITIES As a general rule, the number of sanitary conveniences depends on the number of people likely to be at work at any one time (including full time and part time workers). They should generally be provided within the same building as the workplace. If no exclusive facilities can be provided in the same building, then arrangements should be made with the owner of the building where they are provided or, as a last resort, public facilities may be used. If the workforce is of mixed sex, then the number of both sanitary conveniences and washing facilities that need to be provided may be comparable to those required by UK legislation, being for example: • 1 for 5 or fewer employees • 2 for 6 to 25 employees • 3 for 26 to 50 employees • 4 for 51 to 75 employees • 5 for 76 to 100 employees1. If the workforce is male only, then the number of sanitary conveniences can be split into water closets and urinals, as follows: • 1 to 15 employees -‐ 1 WC and 1 urinal should be provided • 16 to 30 employees -‐ 2 WCs and 1 urinal • 31 to 45 employees -‐ 2 WCs and 2 urinals • 46 to 60 employees -‐ 3 WCs and 2 urinals • 61 to 75 employees -‐ 3 WCs and 3 urinals • 76 to 90 employees -‐ 4 WCs and 3 urinals • 91 to 100 employees -‐ 4 WCs and 4 urinals2. An additional sanitary convenience and washing facility should be provided for every 25 employees above 100 (or fraction of 25). Where the workforce is male only, then it may be that one WC and one urinal should be

Source: gallery.hd.org

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provided for every 50 employees (or fraction of 50) over 100. For particularly dirty work activities, the number of washing facilities should be increased to 1 for every 10 people at work. Where sanitary conveniences provided for staff are also regularly used by the public (i.e. customers, students, etc.) the number of conveniences specified in the above lists should be increased by at least one for each sex. For outdoor occupations such as construction sites, every effort should be made to provide temporary facilities to the same standards as if they were permanent. ASSOCIATED FACILITIES Every WC should be provided with toilet paper and in the case of women’s toilets, facilities for the disposal of sanitary dressings. All washing facilities should be provided with: • Hot and cold water • Soap • Towels or other hand-‐drying facilities. SITING OF FACILITIES Washing facilities should be in the immediate vicinity of the sanitary convenience and changing rooms, where provided. Separate rooms containing sanitary conveniences must be provided and designated by use of signs for men and women, except where the convenience is in a separate room and is capable of being locked. All sanitary conveniences and showers should be arranged to ensure privacy for the users. The rooms containing these facilities must be adequately ventilated (mechanically, if necessary) and well lit, to enable them to be thoroughly cleaned. They should also be kept in a clean, sanitary and orderly condition. ROOMS CONTAINING THE FACILITIES The walls, floors, and ceilings of rooms containing washing facilities and sanitary conveniences should have smooth, impervious surfaces which can be easily cleaned or washed and which cannot trap dust and dirt in corners or crevices. Smooth painted washable surfaces, ceramic surfaces, and stainless steel surfaces are all suitable. The level of cleaning of facilities generally depends on their use, the more they are used, and thus the more frequent the cleaning needs to be3. Regular inspections will be made of the facilities to ensure the required hygiene and safety standards are maintained. There should be emergency arrangements in place to deal immediately with drain blockages and spills that could prejudice health. The facilities should include: • Wash hand basins large enough to allow people to immerse their arms up to the elbow • Constant hot and cold running water or warm water • Soap or other suitable means of cleaning • Nailbrushes, where risk assessment indicates their use • Individual paper towels or other means of drying. Roller towels are satisfactory if they provide a clean drying

surface for each person. Shared towels are not acceptable. Rooms could be fitted with air extraction equipment which keeps the flow of air from the clean to the dirty areas.

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IN FOOD PREMISES The number and location of wash hand basins (WHBs) depend on the type of business, the size of premises and the number of staff employed. They must be readily available for use and close to the sanitary conveniences. They should be provided with a cold water and hot water supply to a maximum of 50ºC, either from separate taps or via a single mixer tap. WHBs should be provided with soap or detergent, and hand drying facilities -‐ paper towels and waste bins, roller towels in cabinets (not fabric towels) or hot-‐air dryers. In food premises, no room containing a sanitary convenience should communicate directly with a room where food is processed, prepared or eaten. If this is not possible, then an intervening space should be provided between, with self-‐closing doors fitted at each side. Health and safety objectives require this space to be ventilated. STORAGE FOR CLOTHING AND CHANGING FACILITIES GENERAL REQUIREMENTS Suitable and sufficient accommodation must be provided for workers’ personal clothing, which is not worn during working hours. The clothes should be able to hang in a clean, warm, dry well ventilated place. If the clothing is wet, it should be able to dry out easily during the course of the working period. The minimum that should be provided is a peg or a hook fixed to a wall for each worker, although personal lockers are the usual standard of provision. There should be sufficient accommodation for personal protective equipment. Where protective clothing is worn, and it becomes damp or contaminated, it should be kept in accommodation which is separate from the worker’s own clothing. This often means that a changing room should be provided to prevent worker’s personal clothing becoming contaminated by a harmful substance. Changing rooms should be provided where special clothing is required to be

worn for work or where workers cannot, for reasons of health or propriety, be expected to change in

another workroom. Separate facilities should be provided for men and women. Changing facilities should be readily accessible from workrooms and eating facilities. They should have adequate seating and contain, or communicate directly with, clothing accommodation and showers or baths if provided. This changing accommodation should be of sufficient size for the maximum number of persons at work expected to use them at any one time without overcrowding or unreasonable delay. The start and finish times of work and the time available to use them should be taken into account when designing these facilities. IN FOOD PREMISES A changing area should be provided for employees to remove their everyday clothes and change into protective clothing. Changing facilities should be provided for protective clothing to be stored in a clean area away from areas where food is handled.

Source: wayfair.com

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FACILITIES FOR EATING MEALS AND RESTING GENERAL REQUIREMENTS Facilities should be provided for workers to take rest and to take meals, where these are regularly eaten at the workplace. This includes seating where workers have to stand to carry out their work and facilities to eat meals where food eaten in the workplace would otherwise become contaminated. Rest areas or rooms should be large enough for all the workers likely to use them at any one time and also for sufficient seats with backrests and tables. Seats provided for rest can also be counted as eating facilities provided there is a surface on which to place food. Where workers regularly eat meals at work, there should be facilities for that purpose. The facilities that should be provided include an electric kettle, a vending machine or a canteen. Facilities for heating food should be provided where hot food cannot be obtained during work hours or where hot food cannot be obtained in, or near, the workplace. Eating and resting facilities should be kept in a clean condition, particularly where the workplace involves the handling of substances hazardous to health, and there is a risk that the substances could contaminate food from clothing and footwear. Restrooms and rest areas must include arrangements to protect non-‐smokers from discomfort caused by tobacco smoke by providing separate areas or rooms for smokers and non-‐smokers, or prohibiting smoking in rest areas and restrooms. Provision must also be made for disabled workers and any pregnant women or nursing mothers at work to rest. Facilities for lying down would normally be available. FACILITIES FOR PREGNANT WOMEN AND NURSING MOTHERS, TOGETHER WITH THE PRACTICAL ARRANGEMENTS Pregnancy is not an illness, but working conditions normally considered acceptable may no longer be so during pregnancy and breastfeeding. In many workplaces, there are risks which may affect the health and safety of new and expectant mothers and that of their child. In most cases, pregnancy goes undetected for the first 4 – 6 weeks. There are specific laws in most countries which require employers to protect the health and safety of new and expectant mothers. A new and expectant mother is normally defined as someone who: • Is pregnant • Has given birth (including stillbirth) within the last six months • Is breastfeeding. ‘The UK Management of Health and Safety at Work Regulations’ 1999 (MHSW) require employers to assess risks to all employees and to do what is reasonably practicable to control those risks. This applies to all employers of any size. Employers must: • Identify hazards in their workplace that could pose a health and safety risk to new and expectant mothers

and take appropriate action to remove or reduce the risk.

Source: nightingalenursinginstitute.com

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They must make this information known to all their female employees of childbearing age, not just those who have informed them they are pregnant. • Carry out a personal risk assessment for a new or expectant mother when they have received notice in

writing that they are pregnant, are breastfeeding or have given birth in the last six months. This should: - Be based on the initial assessment - Take account of any medical advice their doctor or another health professional has provided e.g. By letter - Be carried out with the help of the woman and if appropriate, her union representative - Be monitored and reviewed on a regular basis.

An employer may request, in writing, a certificate from a registered medical practitioner or midwife, confirming the pregnancy WHAT ARE WORK HAZARDS FOR NEW AND EXPECTANT MOTHERS? PHYSICAL RISKS • Movements and postures • Manual handling • Shocks and vibrations • Noise • Radiation (ionising and non-‐ionising) BIOLOGICAL AND CHEMICAL AGENTS INCLUDING • Exposure to infectious diseases • Toxic chemicals • Mercury • Pesticides • Lead WORKING CONDITIONS • Facilities (including restrooms) • Work-‐related stress • Passive smoking • Extremes of cold and heat • Working with VDU’s Some of the above may be covered by specific health and safety regulations. It is important to remember that some hazards can present more of a risk at different stages of the pregnancy. The HSE guidance emphasises the risk of musculoskeletal disorders during pregnancy: “Hormonal changes in women who are pregnant or have recently given birth can affect ligaments, increasing susceptibility to injury.” LIFTING AND HANDLING This includes nursing/care workers, sales assistants, cleaners and two-‐thirds of factory workers. Pregnancy has significant implications for the risk of manual handling. It is important to pay particular attention to women who may handle loads during the three months following a return to work after childbirth.

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SITTING OR STANDING Continuous standing during the working day may lead to dizziness, faintness, and fatigue. It can also contribute to an increased risk of premature childbirth and miscarriage.” It is hazardous working in confined workspaces, or with workstations which do not adjust sufficiently to take account of increased abdominal size. INFECTIOUS DISEASES Exposure to infectious agents such as hepatitis B from bodily fluids could be a problem for cleaners, and toxic chemicals used by hairdressers. RESTING Employers usually must provide “suitable facilities for any person at work who is a pregnant woman or a nursing mother to rest.” NIGHT WORK Special consideration needs to be given to new and expectant mothers who work at night. Some National legislation require that if an employee who is a new or expectant mother works at night and has a certificate from a registered medical practitioner stating that night work could affect her health and safety, she has a right to be: • Offered suitable alternative daytime work on terms and conditions no less favourable than her normal terms

and conditions; or if that is not reasonable • Suspend her from work, on paid leave, for as long as is necessary to protect her health and safety and that of

her child. Night and evening work can be difficult for pregnant women. It increases the risk of fatigue and exhaustion which can pose a risk to the mother, especially in late pregnancy. The risks associated with night work may be even greater if women are getting inadequate rest during the day because they are travelling to and from ante-‐natal appointments. GOOD PRACTICE A growing number of employers are taking the time to listen to pregnant women and to work with them to find solutions. Treating pregnant women well helps an employer to retain and get the best out of valued staff. Helpful changes made by an employer can include: • Re-‐arranging working hours. • Adjusting the amount of overtime to be worked. • Giving greater flexibility about when breaks could be taken. • Providing training in how work may be altered to accommodate changes in posture and physical capability,

including taking breaks. • Offering use of rest facilities. • Allocating tasks to others, e.g. Lifting boxes. This kind of positive action often costs very little and yet significantly improves the experience of pregnant women. It saves an employer money as women can work longer, is less likely to need to take time off sick and is

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more likely to want to return to work after the birth of their baby. Women in manufacturing are most likely to have had a risk assessment. However, it is important to remember that environments such as offices may present serious risks. ANTENATAL CARE All pregnant women have a right to take reasonable paid time off to attend ante-‐natal care, including the time taken to travel. This includes; • Appointments with her midwife, GP or hospital. • Ante-‐natal, parent-‐craft, and relaxation classes. Employers should not ask women to make the time up, take annual leave or to change their normal working hours so that appointments fall out of work time. To do so is in some countries is unlawful. A critical factor in whether women get time off appears to be the attitude or knowledge of their line manager. BREASTFEEDING Employers in some countries have a legal duty to enable their employees to continue breastfeeding once they have returned to work. In such situations, it is normal that the woman must notify her employer in writing as early as possible that she is breastfeeding. Her employer must then carry out a specific risk assessment and take the steps set out above. Specific risks could include: • Working with organic mercury, • Working with radioactive material, and • Exposure to lead. Normally health and safety regulations do not put a time limit on breastfeeding. It is for the women themselves to decide how long they wish to breastfeed, depending on individual circumstances. Access to appropriate facilities for breastfeeding mothers to express and safely store breast milk or to enable infants to be breastfed at or near the workplace may facilitate breastfeeding by working women, and may significantly protect the health of both mother and infant. Protective measures include: • Access to a private room where women can breastfeed or express breast milk • Use of secure, clean refrigerators for storing expressed breast milk while at work, and facilities for washing,

sterilising and storing receptacles • Time off (without loss of pay or benefits, and without fear of penalty) to express milk or breastfeed. PROVISION OF FACILITIES FOR SMOKERS Breathing and inhaling other people’s smoke is called passive, involuntary, or second-‐hand smoking. The non-‐smoker breathes ‘sidestream’ smoke from the burning tip of the cigarette and ‘mainstream’ smoke that has been inhaled and then exhaled by the smoker (ASH, 2004). Second-‐hand smoking is an issue relevant to the workplace, as some employees are exposed to the smoke of fellow employees or that of customers or clients whether they want to be or not.

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Within some countries there exist national regulations that are relevant to smoking in the workplace. LEGISLATION Legislation surrounding the provision for smoking at work is changing dramatically; most countries do not now allow smoking in enclosed places – this would include work environments such as offices. Legislation in most countries allows the provision of designated smoking areas / smoking shelters, however, a growing amount of legislation surrounds this topic and readers are advised to seek reference on this subject related to their work location and local requirements. OUTDOOR SMOKING AREAS While smoking in an enclosed workplace is forbidden in most countries, employers have the discretion to provide an outdoor smoking area, subject to the requirements of the law. These laws have defined outdoor areas broadly as: • A place or premises, or part of a place or premises, that is wholly uncovered by any roof, fixed or mobile. • An outdoor place or premises that are covered by a roof so long as not more than 50% of the perimeter

(outside) is covered by a wall, windows, gate or similar. Again, readers are advised to consult local legislation/regulation on this rapidly changing topic. THE NEED TO TAKE ACCOUNT OF PEOPLE WITH DISABILITIES DISABILITY About one in ten people have some form of disability – that could be a physical disability, vision impairment, hearing impairment, intellectual disability or mental health condition. You may already have employees with disabilities, whether or not those disabilities are readily apparent or known to you. Other employees may acquire a disability in the future. About four out of five people with disabilities acquired their disability as an adult. It makes sense, therefore, to plan and manage for health and safety on an inclusive basis. HIDDEN DISABILITY Some forms of disability are not immediately visible (for example, epilepsy, mild hearing impairment, asthma, or mental health conditions such as depression or anxiety). Often employees with a ‘hidden disability’ choose not to disclose their status because they are concerned that their employer will focus on their disability rather than their ability. If employees are not comfortable about disclosing a disability, their health and safety needs may not be identified and met. It is good health and safety practice, therefore, to create a supportive, non-‐judgemental environment, and to communicate that to all employees. Considerable research has been conducted on the relationship between employees’ wellbeing at work and their work environment. Studies have shown that employees who feel respected in their work environment are more productive and have lower rates of absenteeism (one of the biggest cost items for employers).

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An inclusive work environment where all employees, including those with disabilities, feel comfortable, included and respected makes good business sense. Advances in technology, including assistive technologies, have helped switch the focus from incapacity to capacity for people with disabilities. People with disabilities can work safely and effectively at many jobs provided their specific issues are accommodated, and their needs are built into health and safety planning. ACCOMMODATING DISABILITY AT WORK Under disability legislation in many countries, employers are obliged to take appropriate measures –reasonable accommodation’– (unless the costs of doing so are disproportionate) to enable people with disabilities to have access to employment, to participate or advance in employment and to undergo training. Such measures may include training resources or adaptations to: • Workplace premises to make them more accessible for employees with disabilities • Work equipment • Patterns of working time • Distribution of tasks. Practical examples might include: • A talking lifts with tactile floor buttons • Adjustable-‐height desks • Hands-‐free telephone sets • Later start and finish times • Organising the distribution of work tasks in a team so that staff member who are hard of hearing are not

expected to take minutes. An employer is not normally obliged to provide any facility or treatment that employees can reasonably be expected to provide for themselves. SAFE EVACUATION OF EMPLOYEES WITH DISABILITIES There may be particular challenges to address to ensure that employees with disabilities can exit their place of work safely in the event of an emergency. Different disabilities present different challenges. For example: • Mobility impairment affects the range or speed of movement to varying degrees. • Sensory impairment affects the ability to gather information through the senses such as sight or hearing. • Cognitive or mental health impairment affects the capacity to process information and react appropriately. • With hidden disabilities, the stress of an emergency situation may trigger a condition such as asthma or heart

problems. PLANNING FOR SAFE EMERGENCY EGRESS The key steps in preparing for safe evacuation are: • Initial review of user needs, organisational practice and policies • Develop an egress policy for your organisation

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• Plan for egress • Implement your egress plan • Measure the performance of your egress plan • Review the performance of your egress plan. Consultation and engagement with employees with disabilities are essential elements of identifying risk and planning to address it. Consult your staff members individually and develop and document personal emergency egress plans (PEEPs) for individuals who require them. PEEPs should be developed or modified in response to any issues that emerge during routine fire drills. Regular review of these plans is essential to ensure they are up to date and taking account of any changing needs.

IB10.4 The provision for first aid in the workplace

Where someone is hurt, whether at work or not, there may be an appreciable time before they can get to and be seen by a medically qualified person. The function of first aid is to ensure that the injured person has the maximum chance of surviving a serious injury until that medical assistance is available. In effect, the first aider will attempt to limit the deterioration of the condition of the injured person and, where possible, promote their recovery. In addition to serious injuries, the first aider will also be available to treat minor injuries that would not normally require medical assistance, such as minor cuts. It is important to accept that a first aider is not a medically qualified person and is rendering assistance rather than treating serious conditions. It is important that first aiders apply treatments only in the way that they have been trained to. For example, it is common practice to use a bag of frozen vegetables -‐ often peas -‐ to apply a cold compress to the site of an injury, such as a sprain. However, this can cause an injury in itself. In a newspaper article (Telegraph 3/10/2000) the danger of putting a cold compress straight from the freezer onto the skin was highlighted. The severe cold can cause frostbite that may lead to permanent skin damage. In one recent case, a PE teacher needed an emergency operation to remove tissue damaged by the extreme cold of such a cold compress. The compress was left on for over 45 minutes while the recommended maximum time is 30 minutes. The recommendation in the authorised manual of the Voluntary Aid Society 1997 (First Aid Manual. 7th edn. London: Dorling Kindersley) is that frozen vegetables may be used as a cold compress, but they must be wrapped in a cloth or towel to prevent direct contact with the skin. If such guidance is ignored by first aiders, they could place themselves and their employers at risk of litigation for not undertaking proper procedures during treatments. TREATMENTS OTHER THAN FIRST AID A first aider should never be expected to undertake procedures outside their training. For example, they must not give tablets or medicines to treat illness. However with the assistance of a suitably trained first aider the chance of injuries deteriorating to a serious condition, or the possibility of death, is significantly reduced. However in some cases, there are specific risks of injury in certain workplaces for which first aiders can be specially trained to assist, for example, special treatments for exposure to certain hazardous substances.

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In these special cases where the first aider has received the appropriate training, there is no prohibition on them administering this assistance. FIRST AIDERS Where the assessment of the first aid needs of a particular area indicates that there is a significant risk of injury, then one or more first aiders will need to be trained and appointed. The exact numbers that will need to be appointed will depend on the level of risk. SELECTION The first aider will need to react correctly to a difficult situation and so should be selected to be capable of coping with an emergency situation along with the ability to learn the skills necessary to carry out their function. They should also have the physical ability to deal with the demands of the emergency procedures. One aspect that can be forgotten is that a first aider may well have to react to a situation with no notice. It is, therefore, necessary that they can leave their normal work immediately to deal with an emergency situation. TRAINING The first aider must possess certain minimum skills to carry out their duties adequately. To this end, the first aider must attend and pass a course approved by the appropriate authority of a country e.g. Ministry of Health in the UAE, HSE in the UK. This course initially consists of a 4-‐day course (depending upon the trainees’ ability, so the course may sometimes be longer) that must be refreshed at no more than 3-‐year intervals, usually on a 2-‐day course. FIRST AID COMPETENCIES On completion of the training, successful candidates will be able to do the following: • Act safely, promptly and effectively when an emergency occurs at work • Administer cardiopulmonary resuscitation (CPR) promptly and effectively • Administer first aid safely, promptly and effectively to a casualty who is wounded or bleeding • Administer first aid safely, promptly and effectively to a casualty who:·∙ - Has been burned or scalded·∙ - Is suffering from an injury to bones, muscles or joints·∙ - Is suffering from shock·∙ - Has an eye injury ·∙ - Maybe poisoned ·∙ - Has been overcome by gas or fumes

• Transport a casualty safely as required by the circumstances of the workplace • Recognise common major illnesses and take appropriate action • Recognise minor illnesses and take appropriate action • Maintain simple factual records and provide written information to a doctor or hospital if required

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ADDITIONAL FIRST AID KNOWLEDGE In addition, the successful candidate will have knowledge of: • The importance of personal hygiene in first-‐aid procedures • The legal framework for first aid provision at work • The use of first aid equipment provided in the workplace • The role of the first aider in emergency procedures In some workplaces, there may well be particular risks that require special treatments. Where this is the case, and the first aider is capable of administering them, extra training should be provided in addition to the normal training; however this extra training does not need to be on an appropriately approved course. The three-‐year interval between the re-‐qualification courses is quite long, and skills, and abilities fade. It is thus recommended that the first aiders be provided with the facilities to refresh their training at more frequent intervals. This may be achieved by arranging attendance on a short refresher course or, at the least, by affording the first aiders time for self-‐directed revision. A particularly effective means of achieving this is to encourage all the first aiders in an organisation to meet on a regular basis to share experiences and refresh their knowledge together. It is also important that first aiders are aware of external sources of advice that they can contact. APPOINTED PERSONS It is recognised that there are some situations whereby the provision of a fully trained first aider may not be required. For example, the workplace may be a lower risk establishment such as an office with very few people working there. Where there is not a need for a fully trained first aider, there is still a need for a person to be appointed who has sufficient training and capability to take charge of the situation where a person is injured or taken ill at work. In addition there is a need for someone to look after the equipment and facilities provided by the employer for first aid and re-‐stock where necessary. This appointed person does not have any requirements for training. However, they need to be able to assess a situation, pass on the relevant information if it is necessary to summon medical assistance and know the requirements for first aid equipment. As such, there is a need for them to have some training. It is recommended in the UK HSE guidance (L74) that they attend a training course that will teach them the basics: • What to do in an emergency • Cardio-‐pulmonary resuscitation (CPR) • First aid for the unconscious person • First aid for the wounded or bleeding ADEQUACY OF PROVISION To assist in what various legislation may require, reference is made to the UK Health and Safety (First-‐Aid) Regulations 1981 (S.I. 1981, No. 917). These regulations require the adequate provision of equipment, facilities and numbers of first aiders as is appropriate for the risks presented by the workplace and may want to be used as established ‘best practice.'

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In addition to the workers at fixed workplaces, the employer must also ensure that those employees that are away from the employer's premises, for example, travelling or home office workers, also have suitable provision to enable them to treat themselves. The main factors that need to be considered to determine the adequacy of first aid provision include: • The hazards in the workplace and the likely level of risk they present • The number of employees that will be present on the site at any time • An assessment of the likelihood of accidents occurring based on the previous history of occurrences • The distribution of the workforce around the site • The likely response time of the local emergency services and holiday cover ASSESSING THE NECESSARY LEVEL OF FIRST AID PROVISION • What level of risk of injury or ill health does the general risk assessment of the area indicate (as a higher risk

will require a higher provision of first aid facilities)? • Are there any particular risks that are higher than usual due to the nature of the work or the materials or

substances used (which may require more or specialised means of treating the injuries caused)? • Are there certain areas of the site where the risks are significantly higher than others (e.g. a workshop in a

predominantly office-‐based site)? • Are the numbers of people for whom first aid cover must be provided large or small (as larger numbers

require a first aid provision)? • Is there a high or low level of injury incidents recorded in the past (as large numbers suggest a need for a first

aid provision)? • Have past incidents involved more of one type of incident than others (which will suggest a higher provision

of the means to treat it being available in the first aid kits than would normally be recommended)? • Will there be present on sites more vulnerable people, such as inexperienced or disabled employees or those

with special health problems (which will possibly give special requirements for ready access to the first aid facilities or for the provision of special equipment)?

• Are the work areas in separate buildings around the site or on more than one floor of a multi-‐storey building (which will require a higher level of provision of first aid facilities to ensure ready access to all staff)?

• Are there any secure areas in which employees normally work (which may require special access arrangements by the first aiders)?

• Do different groups of employees work at different times, such as shift workers or work outside normal office hours (which would require a higher level of first aid provision to ensure that it was adequate for all employees)?

• Is the likely response time of the emergency services higher than normal, for example due to remoteness or difficulty of access (which may require special arrangements to be made to facilitate the transport of the seriously injured to a medical treatment facility)?

• Are any of the employees likely to work away from the organisation's normal premises, such as at a home office or on the road or likely to work alone for significant periods (which would suggest the need to provide individual first aid kits along with basic training in their use and the possible need for some form of personal communicator to them)?

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• Is any of the employees likely to spend significant portions of their time working on sites occupied or controlled by other employers (which would suggest a need for co-‐ordination of first aid provision, or separate provision by each employer)?

• Are any young people (under 18 years of age) or work experience trainees working on the site (which may alter the level of provision of first aid facilities that needs to be made at the time when they are present)?

• What level of first aid provision will be made available to members of the public accessing the premises (which may compromise the level of first aid provision to employees -‐ see Provision for Non-‐employees)?

• Will there be any problems in informing employees of the first aid arrangements, possibly due to disability, reading or language difficulties (which will require special arrangements for informing them to be made)?

• Are there particular times, such as during maintenance closures, that the provision of first aid facilities for the employees present may be significantly compromised by the absence of first aiders and appointed persons (which may require a temporary extra cover to be specially arranged)?

NUMBER OF FIRST AIDERS The number of first aiders that will be needed at any site will be dependent on the level of need assessed. However, some guidance can be given for minimum levels of provision. In some low-‐risk situations an appointed person would be sufficient as a minimum. However it is recommended that there is at least one fully qualified first aider at the site where this is practicable.

CATEGORY OF RISK NUMBER OF PERSONS EMPLOYED

SUGGESTED NUMBER OF FIRST AID PERSONNEL

Lower Risk e.g. shops, offices, libraries

<50 At least one appointed person 50 to 100 At least one first aider >100 One additional first aider for every 100 employed

Medium Risk e.g. light engineering and assembly work, food processing, warehousing

<20 At least one appointed person 20 to 100 At least one first-‐aider for every 50 or part thereof

>100 At least one first-‐aider for every 100 or part thereof

Higher Risk e.g. most construction, slaughterhouse, chemical

<5 At least one appointed person 5 to 50 At least one first aider >50 One additional first aider for every 50 employed

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CATEGORY OF RISK NUMBER OF PERSONS EMPLOYED

SUGGESTED NUMBER OF FIRST AID PERSONNEL

manufacture, extensive work

Where there are hazards for which additional first-‐aid skills are necessary

In addition, at least one first aider trained in the specific emergency action

EQUIPMENT & RESOURCES The minimum first-‐aid equipment needed is a first aid kit. Other items of equipment can form part of the provision, dependent on the assessment of need, but these are not mandatory. FIRST AID KITS The first aid kit is the mainstay of the first aid provision. There is a recommendation in the guidance to the Health and Safety (First-‐Aid) Regulations 1981 (S.I. 1981, No. 917) that it should be easily accessible, the requirement in the regulations is that it should be provided. There is a potential conflict between a first aid kit that is easily accessible and one that is empty due to neglect or abuse. If the first aid kit is made readily available by being wall mounted, it is necessary to ensure that it is adequately stocked at all times and maintained in a condition fit for use. This requires a very regular checking regime, dependent on the likely use or potential for abuse, but probably at least once a day in an area of high traffic. An alternative is to issue a first aid kit to each first aider for them to keep safe and ready for use. This may mean that it is not available for anyone other than the first aider to use at a particular time. However if there is sufficient provision of first aiders and the means to contact them, the problems that this may cause will be avoided, and the problem of having a first aid kit that is unusable will also be avoided. A further complication of a freely available first aid kit is the possibility that the person self-‐treating themselves will not be able to render the best treatment and the high likelihood that the relevant records will not be completed. The lack of correct records can lead to a lack of information on the incident and the lack of opportunity to correct the cause of the injury. The contents of the kit must be regularly checked and restocked. For this to be effective, it is recommended that a separate replenishment store of first aid materials is held. A point of note is that many of the first aid supplies have a shelf life, for example, many of the sterile items. For this reason, it is important not only to check the content of the kits but also to check that the items are still in date. For most of the items with the exception of eyewash, the shelf life is many years, and so this is not a serious problem. However, it is not recommended that large quantities of first aid materials are kept in the

Source: CSS

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central stock unless there is some evidence that they will be used -‐ the benefits of bulk buying can often be far outweighed by having to dispose of unused out-‐of-‐date items. Whatever the content of the kit it must be immediately identifiable. The case should protect the contents from dirt and damage, but there is no requirement that it be made of a particular material or even be of rigid construction. In some instances a rigid case would be preferable to protect against damage. However there are some instances, notably for portable or so-‐called 'fast response' kits, where a soft padded case, possibly with shoulder straps, would be of more use. The colour of the case also is not specified, however, green or hi-‐visibility orange is quite common. WORKPLACE FIRST AID KIT It is important not to 'overload' the case with everything that could possibly be required; on the other hand, it is important that any items specially indicated as being necessary by the assessment of need are included. Since the first aiders are not permitted to give tablets or medication, even proprietary over-‐the-‐counter treatments, no tablets or other medicines should be kept in the first aid kit and only those things that will be useful for giving first aid. One possible conflict with this advice comes from the recommendation in the authorised manual of the voluntary aid societies, First Aid Manual (7th Ed) 1997, Dorling Kindersley, London, in which it is suggested that a conscious casualty suffering pain from a heart attack is given one aspirin tablet to chew. Since the guidance to the regulations specifically prohibits the keeping of tablets in the kit, it is recommended that aspirin could be kept nearby the kit but not in it -‐ always noting expiry dates on them. THE SUGGESTED CONTENTS OF A FIRST AID KIT The following is a list of suggested items for the contents of the first aid kit, but other items can be included where necessary: • A leaflet giving general guidance on first aid -‐ the HSE publication Basic Advice on First Aid at Work

(IND(G)163L is generally acceptable, but there are others available • 20 individually wrapped sterile adhesive dressings (assorted sizes) appropriate for the work environment

(detectable dressings should be available for the catering industry) • Two sterile eye pads • Four individually wrapped triangular bandages (preferably sterile) - Six safety pins - Six medium-‐sized individually wrapped sterile unmedicated wound dressings (approximately 12 cm ´ 12

cm) - Two large sterile individually wrapped unmedicated wound dressings (approximately 18 cm ´ 18 cm) - 1 pair of disposable gloves

TRAVELLING FIRST AID KIT The first aid needs of employees who are working away from the organisation's premises can be met by the provision of a suitable travelling first aid kit, some instruction on its use and (where necessary) a means of communication.

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THE SUGGESTED CONTENTS OF A TRAVELLING FIRST AID KIT The following is a list of suggested items for the contents of the travelling first aid kit, but other items can be included where necessary: • A leaflet giving general guidance on first aid -‐ the HSE publication Basic Advice on First Aid at Work

(IND(G)163L is acceptable, but there are others available • 6 individually wrapped sterile adhesive dressings • 1 large sterile unmedicated dressing (approximately 18 cm ´ 18 cm) • 2 triangular bandages • 2 safety pins • Individually wrapped moist cleansing wipes • 1 pair of disposable gloves EYE WASH One area of first aid provision that seems to cause some difficulty is the means to irrigate the eye. This would be necessary if there were a foreign body in the eye (but not if it were embedded or sticking out of the eye) or if a hazardous substance were splashed into the eye for which the manufacturer's safety data sheet first aid section recommended irrigation with water. The advice given in the authorised manual of the voluntary aid societies, First Aid Manual (7th ed) 1997, Dorling Kindersley, London, is to use water. The quantity of water used depends whether a foreign body is being removed or a harmful substance is being flushed away -‐ however clean mains-‐fed tap water is the best means of doing this. In the guidance to the UK Health and Safety (First-‐Aid) Regulations an allowance is made where this mains-‐fed tap water is not readily available, for the provision of eye wash solution to replace it. The solution would be at least a litre of sterile water or sterile normal saline (0.9%). The problem with eye wash solution is that it is expensive and once opened and used, the remainder must be disposed of. The solution often has quite a short shelf life -‐ sometimes only six months (usually marked on the container) which adds to the general running expenses of this means of eye irritation. In addition, storing it close to where it will be needed can often result in it being covered in dust or being damaged and thus wasted. In some work circumstances, particularly for outdoor workers, the impracticality of providing running water makes this the only reasonable option. However, the high running costs of providing this means of eye irrigation are sometimes reasonably balanced, over a period of time, by the installation of piped mains water, possibly to a purpose-‐built eye-‐wash station. Where bottles of solution are the only means of providing this facility, it is important that they are kept clean and secure, checked regularly for damage and to ensure that they are in-‐date and disposed of and promptly replaced when used. ADDITIONAL MATERIALS AND EQUIPMENT The recommended minimum contents of a first aid kit are not exclusive and can be added to with items that are useful to first aid, medicines, and tablets needing to be kept away from the kit. Some items are particularly useful and some less so. However if a special need for equipment or first aid materials arises from the

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assessment of need, then it must be supplied in all first aid kits. Examples of the types of items that may be considered for inclusion (but are by no means a requirement) could include: • Scissors • Protective aprons • Sterile dressings (probably the 5 cm x 5 cm are the most useful) • Tubular gauze bandages (and applicator) for finger dressings • Adhesive tape • Individually wrapped moist wipes • Resuscitation protective face shield If the assessment and the likely response time of the emergency services suggest that some means of moving a patient is necessary, such as a stretcher or evacuation chair, it should be stored in a place that is secure, yet readily available for use. However, it is important that anyone expected to use it, must be fully trained in its correct use or the injuries that could result from its misuse could lead to litigation for the organisation. It is possible that the circumstances of the rescue or treatment of an injured person place the first aider at sufficient risk to require some form of personal protective equipment, e.g. a hard hat or some form of a protective garment. In addition, it may be necessary to provide blankets or some other form of protection for the patient. Where these are necessary, they should be readily available for use but secure from misuse or accidental damage. Their positioning will depend on the need. • It may be appropriate to issue the equipment to individual first aiders trained in its use • It may be more appropriate to hold it in a central (secure) location • It may be more appropriate to site the equipment near to the area where the risk that may require its use is

situated FIRST AID ROOMS Whilst not always necessary, a first aid room can provide a very useful addition to the first aid provision. In smaller organisations or where the response time of the emergency services is short, it is less likely to be necessary to have a dedicated first aid room. In larger or more spread out premises or where the response time for the emergency services is likely to be extended, it would be advisable to have such a facility; the decision would be based on the assessment of need. If such a facility is available, it is advisable to restrict its use solely for first aid. Room to be used as a rest area, or for nursing mothers or for medical examinations and health surveillance should be separate so as not to compromise its first aid function. Where there is not an Occupational Health function available on site, it is likely that the first aid room will not be permanently staffed. As a result, it is important to ensure that arrangements are made for a first aider to be present and remain with an injured or unwell person that is in it. MINIMUM STANDARDS FOR THE SPECIFICATION OF AN EFFECTIVE FIRST AID ROOM Where it is decided that a first aid room is necessary, there are certain minimum standards that should be met to ensure that it is effective: • It should be easily accessible to stretchers or any other equipment used to carry out patients and casualties.

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• It should be large enough to contain the equipment necessary for its use, e.g. a couch, desk, chair, etc. and sufficient extra space to allow the first aider to move around the patient whilst giving first aid.

• If it is intended to store the extra first aid materials in it, there should be sufficient space for a cupboard or other storage facility in which to keep them.

• Since the room needs to be kept comfortable, clean and sanitary, the surfaces should be washable, and there should be adequate heating, lighting, and ventilation.

• It is important that the room is kept clean and tidy and is accessible to the first aiders and anyone that needs to use it at all times.

• It is important to remember that some of the waste from the first aid room may be a clinical waste, posing particular hazards, which must be disposed of correctly and not in the normal industrial waste.

• Since the patient may well need to be transported away from the room, it is necessary that there is suitable access that can accommodate the means of moving the patient, such as a stretcher or trolley.

• It is most useful to have the first aid room on the ground floor, but where this is not possible it is recommended that there is clear access to lift.

• The room will often form the focal point for people seeking help. It is a legal requirement in some countries that a sign marks it so that it cannot be missed from the outside.

A clearly visible notice indicating the names of the first aiders with their locations and how they can be contacted should also be placed outside the room. CONTENTS OF A FIRST AID ROOM The facilities and equipment which should be provided in first aid rooms are as follows: • Sink with running hot and cold water • Drinking water (if not available on mains tap) and disposable cups • Paper towels • Smooth topped washable working surfaces • A range of first aid equipment (at least to the standard required in first aid boxes) and proper storage • Chair • Couch (with waterproof cover), pillow and blankets • Clean protective garments for first aiders • Suitable refuse container (foot operated) lined with appropriate disposable yellow plastic bags, i.e. for clinical

waste • An appropriate record keeping facility • A means of communication, e.g. a telephone RECORDS There is no particular legislative requirement to keep records of first aid. However, it is most useful for the investigation of the cause of the need for first aid to have accurate records. This record could also be used in the event of any dispute over the content and appropriateness of the treatment given or whether the injured person refused treatment. REQUIREMENTS FOR A FIRST AID RECORD The record should include:

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• The date, time and location of the incident causing the illness or injury • The name of the injured or ill person and their normal job function • The immediate cause of the injury or illness (if known) • The details of any treatment given (and whether it was refused) • The details of the actions taken after treatment, such as sent to hospital, returned to work or similar • The name and signature of the treated person (if possible) • The name and signature of the first aider or person giving the treatment In addition to the records of treatment, it is recommended that the records of the training of the first aiders (and any provided for appointed persons) are also recorded. Since the training has to be refreshed at three-‐year intervals, it is advised that some system to remind the person organising the training is used to ensure that the refresher course is booked in good time. INFORMING THE EMPLOYEES All employees should be informed of the arrangements that have been made for the provision of first aid. The content is not laid down in any national legislation but must cover all the arrangements and particularly any special procedures at the site that the employee will be working. INFORMATION ON FIRST AID TO BE PROVIDED TO EMPLOYEES The information to be given to employees would include: • The location of the first aid equipment • Any first aid facilities, such as first aid rooms or special equipment • Who will provide first aid, i.e. the first aiders and the appointed persons • How the first aid providers can be contacted • Any special procedures that must be used It is important that all employees know this information and understands it. In particular, it is important to ensure that new starters and employees transferring from other areas are particularly made aware, perhaps during an induction course. The information should be made widely available by having at least one prominently placed notice of the details on the site. In addition it is important to ensure that those members of staff that may have difficulties with reading this notice, for example because of language difficulties or disability, are afforded the information in a form that they can use, e.g. in their own language.

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Reference

Hygiene (Commerce and Offices), ILO Convention, 1964 (No 120) (C120) and Recommendation (R120) Welfare Facilities Recommendation, R102, 1956 Working Environment (Air, Pollution, Noise and Vibration) Convention, 1977(No 148) (C148) and Recommendation Ambient factors in the Workplace, International Labour Organisation (ILO) Code of Practice (CoP) Encyclopaedia of Occupational Health and Safety, ILO Lighting at Work, HSG38, second edition 1997 International Labour Standards, Welfare Facilities Recommendation, R1021ntemational Labour Organisation, Geneva, 1956 International Labour Office, Ambient Factors in the Workplace, an ILO Code of Practice, ILO, Geneva, 2001. ISBN 922111628X Chapter 8: Thermal International Labour Standards, Occupational Health Services Convention, C161, International Labour Organisation, Geneva, 19850ccupational Health Services at the Workplace, Dr V Forastieri, ILO

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