© Imperial College LondonPage 1 Foundation Training in Biological Safety.

© Imperial College London

Foundation Training in Biological Safety


Module 2Hazardous chemicals


Routes of exposure

Inhalation

Skin contact

Ingestion

Gases, fumes, vapours, very fine powders

Corrosive liquids and those that readily cross the skin barrier

Dense solids

Most serious

Least likely

Most readilyabsorbed

Least readilyabsorbed


Risk factors

Intrinsic hazard associated with the substance

Low health hazard

Substances designated as irritant (those that affect the skin and sometimes the eyes)

Medium health hazard

Substances designated as corrosive, irritant (particularly by the inhalation route) or harmful (particularly by the inhalation route)

High health hazard

Substances designated as toxic, very toxic, carcinogenic, mutagenic and those that may impair fertility or harm the unborn child

Severity of hazard


Risk factorsRisk Phrases

All hazardous substances are allocated Risk Phrases that describe the particular hazard(s) associated with that substance

Risk Phrases can be found on the Material Safety Data Sheet (MSDS) supplied with the substance.

It is a legal requirement for suppliers to provide safety information in the form of an MSDS


Risk factors

Currently 60+ Risk Phrases listed under

Chemical (Hazard Information and

Packaging for Supply) Regulations

(CHIP)


Risk factorsIt is also a legal requirement for suppliers to provide appropriate hazard labelling for chemicals

How many types of hazard label are there?

Packing and Supply Hazard Warning Transport


Risk factors

Suppliers must also identify and label

chemicals that present a safety risk as opposed to

a health risk…..

….and those that have an environmental impact


Risk factors

Suppliers must also package

chemicals safely


Risks factorsWorkplace Exposure Limits (WELs)

In addition to Risk Phrases, some hazardous substances have occupational exposure limits set under COSHH in order to protect the health of the worker

These are airborne concentrations, averaged over a time period, that must not be exceeded

Information on WELs can also be found on the MSDS for the substance:


Risk factors

Physical properties

Dictate the potential to become airborne e.g. Liquids: high boiling point > medium BP > low BP Solids: pellets / granules > crystalline > dusty

Quantity

e.g. small > medium > high (<1g [ml]) (1 – 100g [ml]) (>100g [ml])


Risk factors

By multiplying values for:

INTRINSIC HAZARD

x

PHYSICAL PROPERTIES

x

QUANTITY

….we can arrive at a figure that gives an indication of overall risk factor


Control measures

Substitute the hazardous chemical with a safer alternative

EthidiumBromide

Prevention of exposure takes priority over control

Use a safer form of the same chemical

Exclude non-essential personnel from the area

Access control systems

No write up areas in labs

Hazard zoning


Control measuresMinimise the quantities used, stored and transported

Store hazardous chemicalsin an appropriate manner

Ventilation:

use fume cupboardswhere necessary…...and check that theyare being maintained


Wear appropriatePersonal ProtectiveEquipment (PPE)

Dispose of chemical waste properly: sink or specialist waste contractor?

Transport hazardous

chemicals

using appropriate

containment methods

Control measures


Control measures

Observegoodhousekeeping

Ensure users are provided with sufficient information, instruction, training and supervision

Ensure that suitable emergency procedures are in place


No horseplay in the lab !!!!!!!!!!!!!!!!!


Carrying out and recording the COSHH risk assessment

STEP 1:Identify the hazards STEP 2:Identify who may be at risk

STEP 3:Establish control measures

STEP 4:Record the assessment

STEP 5:Review the assessment


Laboratory activities that present a specific risk

Activity Control measuresWeighing Consider using fume cupboard or other benchtop

enclosure such as weighing station

Pipetting Consider using fume cupboard and or drip trays; dispose of pipette tips properly; use good pipetting technique; clean and maintain automatic pipettes

Shaking / mixing Consider using fume cupboard in conjunction with PPE

Centrifugation Ensure compatibility of tubes with chemicals; balance tubes; PPE; clean-up procedures and training

Syringe filtering Consider alternative methods; use Luer lock fittings; select right pore size; dilute sample; FC and PPE

Use of sharps Eliminate wherever possible; select right tool for job; wear appropriate PPE; ensure safe disposal

Elevated temperature Lower temperature if possible: use fume cupboard; cover or partially cover; reduce surface area

High pressure equipment Consider location of equipment in conjunction with PPE


Accidents do happen……Chemical splash to face / eyesChemical splash to hand / armChemical splash on laboratory coatChemical injected beneath skin by needleExposure by inhalation (sometimes including eye irritation)Numerous reports of ‘solvent’ smellsAllergic reaction attributed to chemical contactAcute asthma attackSpillage onto bench / floorChemical in mouth – rare

….and a skin blister arising from self treatment of wart on foot with liquid nitrogen!


……so report them


Some other legislation relating to chemicals

Dangerous Substances and Explosive Atmospheres Regulations (DSEAR)

Home Office Drug Precursor Legislation

Chemical Weapons Act

Anti-Terrorism Crime and Security Act


Sources of further information

Internal

External

Safety Department website:http://www3.imperial.ac.uk/safety/guidanceandadvice/chemicalsafety

http://www3.imperial.ac.uk/safety/guidanceandadvice/hazwaste

HSE:http://www.hse.gov.uk/index.htm

Sigma Aldrich:http://www.sigmaaldrich.com/Area_of_Interest/Europe_Home/UK.html

Wikipedia:http://en.wikipedia.org/

http://www3.imperial.ac.uk/safety/guidanceandadvice/chemicalsafety

http://www3.imperial.ac.uk/safety/guidanceandadvice/chemicalsafety

http://www3.imperial.ac.uk/safety/guidanceandadvice/hazwaste

http://www.hse.gov.uk/index.htm

http://www.hse.gov.uk/index.htm

http://www.sigmaaldrich.com/Area_of_Interest/Europe_Home/UK.html

http://www.sigmaaldrich.com/Area_of_Interest/Europe_Home/UK.html

http://en.wikipedia.org/


1.Is the substance flammable?No. Flammability is usually indicated in Sections 3 (Hazards Identification) and 15 (Regulatory Information)

2. What is the UK Workplace Exposure Limit for this substance?2ppm (Section 8 - Exposure Controls and Personal Protection). OEL is the Occupational Exposure Limit

3. How would you dispose of 5 Litres waste chloroform?Via specialist waste contractor organised by Estates Helpdesk – (Section 13, Disposal Considerations).

4. How would you store the substance in the laboratory?In a solvent cabinet with appropriate signage and preferably equipped with a spillage tray. Section 7, Handling and Storage offers little useful guidance in this instance.

5. Would you need to wear a respirator for routinely handling laboratory quantities of this substance?If the substance is handled properly in a functional, well maintained fume cupboard, this should be sufficient to ensure that respiratory exposure is minimised and kept below the 2ppm WEL. Respiratory protection would probably only be envisaged for dealing with a large spill outside a fume cupboard.

Workshop Exercise 1


Workshop Exercise 2

SCENARIO:

You enter a laboratory first thing in the morning and notice an odour. You recognise that two specimen jars on the benchtop have cracked and spilled 4% formaldehyde onto the benchtop and an area of the floor. There is still evidence of liquid present.

WHAT DO YOU DO NEXT?


MODEL ANSWER

1. Leave the room again immediately.

2. Close the door and secure if possible.

3. If the door cannot be secured, attract the attention of a colleague to stand by the door or prepare some temporary warning signage to affix to the door.

4. Report the incident to your Group Safety Adviser / DSO.

5. Nobody should enter the room until the airborne concentration of formaldehyde is established. This can be determined using a portable formaldemeter – several meters are kept by the Safety Department and others are held locally.

6. Once the readings have been established there are two options:

a. A member of staff can enter wearing suitable respiratory protective equipment and clean the spillage up using a polymerising agent.

b. The room can be left vacant until the formaldhyde has evaporated completely. The length of time that this takes will be dependent upon the quantity spilt and the ventilation standards within the laboratory.

7. Complete a dangerous occurrence report in accordance with established College procedures.

© Imperial College LondonPage 1 Foundation Training in Biological Safety.

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Transcript of © Imperial College LondonPage 1 Foundation Training in Biological Safety.