Health Hazard Assessment in System Safety …Health Hazard Assessment in System Safety Evaluation...

Health Hazard Assessment in System Safety Evaluation

Part 2 Chemical Risk Assessment

International System Safety Society Training Symposium August 4, 2014

Mark Geiger, MS, CIH, CSP, CIH Naval Safety Center Liaison Office [email protected] 703 695-4703

Rodney Simmons, PhD, CSP, The Petroleum Institute, Abu Dhabi, United Arab Emirates

[email protected]

mailto:[email protected]

mailto:[email protected]

Tutorial Health Hazard Assessment Time Topics Comments

0800-0850 • Introduction and Overview

• Health hazard assessment process

• Physical hazards

• Relevance of health hazard assessment to the systems engineering process

• Focus areas – why worry • Ergonomic and physical hazards

0900-0950 • Chemical hazards

• Background • Preliminary Hazard Identification • Exposure and Risk Assessment • Controls • Sources of Information

1030-1130 • Noise overview

• Exercises in health hazard assessment

-Noise the most prevalent occupational health hazard- it can be evaluated and often controlled Health hazard assessment of a single hazard (noise, physical agent or chemical)

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Importance of Chemical Risk Management • The production and use of chemicals is fundamental to all

economies. – Global chemical business > $1.7 trillion per year. – U.S. chemicals

• $450 billion business • Exports > $80 billion per year.

• Chemicals directly or indirectly affect our lives and are essential to our food, our health, and our lifestyle.

• Important chemical information necessary to protect people and the environment – Hazardous properties of chemicals, – Control measures, – Allows the production, transport, use and disposal of

chemicals to be managed safely. • Source A Guide to The Globally Harmonized System of Classification and Labelling

of Chemicals (GHS) https://www.osha.gov/dsg/hazcom/ghs.html#3.2

3

Presenter

Presentation Notes

The sound management of chemicals should include systems through which chemical hazards are identified and communicated to all who are potentially exposed. These groups include workers, consumers, emergency responders and the public. It is important to know what chemicals are present and/or used, their hazards to human health and the environment, and the means to control them. A number of classification and labelling systems, each addressing specific use patterns and groups of chemicals, exist at the national, regional and international levels.

https://www.osha.gov/dsg/hazcom/ghs.html

Health Hazard Evaluation Part 2

• Outline of the Mil Std 882 Task 207 Health Hazard Assessment Process

• Background material needed to evaluate “chemical” hazards

• Application of the Health Hazard Evaluation Process to chemical materials/processes

• Links to process improvement and systems engineering (time permitting)

• Additional information (in background materials)

4

Task 207 Health Hazard Analysis Process

1. Purpose-Perform and document a health hazard assessment to identify human health hazards

– Evaluate proposed hazardous material and processes

– Propose measures to eliminate hazards • Or to reduce risks when the hazards can’t be

eliminated

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• HHA Process • Background material • Chemical Health

Hazard Evaluation • Mitigation/control

Task 207 Health Hazard Analysis (HHA) Process

2. Task Description: Perform and document HHA including potential effects from exposure to hazards -What is a health hazard- a condition inherent to operation, maintenance, storage, transport, use or disposal that can cause death, injury, acute or chronic illness, disability or reduced job performance

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Mil Standard 882 Task 207 Health Hazard Analysis (HHA) Process

Three (3) Categories of Information a. Hazard identification –name and affected system components and

processes (where it’s occurs) b. Start with chemical inventory and process description

1. Exposure pathway- how people can be exposed to include mode of transmission (inhalation, absorption, ingestion)

2. Exposure characterization –level of energy or concentration- what type of models can be used?

3. Sometimes the evaluation will be quantitative (versus qualitative) c. Severity and probability of exposures

- Describe the potential acute and chronic health risks Use information to develop d. Mitigation strategy for each hazard

– Describe a target mitigation strategy for each hazard based on the degree of risk reduction



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Very Limited Toxicology Introduction

• Dose-response

• Target organs and mechanism of actions

• Chemical and physical properties

• Standards and their limitations

• HHA Process • Background material • Chemical Health Hazard Evaluation • Mitigation/control

8

Dose-response ~ exposure – effect

Threshold (limited effect) Where is this point? It differs among people

Saturation Variables include • Prior exposures • Individual sensitivity • Limitations of exposure evaluation • What’s an acceptable response or risk

Threshold (limited effect) Generally considered “safe” for members of working population

9

Presenter

Presentation Notes

Source Introducing dose-response curves http://dwb4.unl.edu/Chem/CHEM869Z/CHEM869ZLinks/www.curvefit.com/introduction89.htm

Target Organs and Mechanism of Actions and Routes of Entry

• Target organs – affected body systems • Mechanism of actions- how system is affected • Routes of Entry – how the toxic material reaches the

target

Substance Target Organs

Route of Exposure or entry

Mechanism of Action

Symptoms/ effects

Solvent Skin Contact Defat cracking peeling contact dermatitis

Solvent Liver Respiration Cellular injury

Cirrhosis, Cancer?

Solvent Central Nervous system

Respiration, contact

Not fully known

Dizziness, “intoxication Long term Central Nervous system (CNS) impacts

• HHA Process • Background

material • Chemical Health


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Target Organs and Mechanism of Actions and Routes of Entry

• Target organs – affected body systems • Mechanism of actions- how the toxin acts • Routes of Entry – how it reaches the target

Substance Target Organs

Route of Exposure or entry

Mechanism of Action

Symptoms/ effects

Carbon Monoxide

Red blood cells

Inhalation (also smoking and some chemicals)

Competitive bonding with oxygen on red blood cells

Diminished ability to transport oxygen

Carbon Monoxide

Central Nervous System (CNS)

Respiration, contact

Decreased oxygen availability

Headache, diminished cognitive ability, unconscious's, brain damage, potential death 11

Chemical properties and physical properties

State of matter affects potential routes of entry • Dusts • Fumes • Mists

• Aerosols • Fibers • Vapors • Gases




12

Physical Hazards

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Explosives Flammable Gases Flammable Aerosols Oxidizing Gases Gases under Pressure Compressed Gases Liquefied Gases Refrigerated Liquefied Gases Dissolved Gases Flammable Liquids Flammable Solids Self-Reactive Chemicals

Pyrophoric Liquids Pyrophoric Solid Pyrophoric Gases Self-heating Chemicals Chemicals, which in contact with water, emit flammable gases Oxidizing Liquids Oxidizing Solids Organic Peroxides Corrosive to Metals Combustible Dusts

Slide courtesy of OSHA Training Institute

Types of Chemical Hazards • Acute Toxicity • Skin Corrosion/ Irritation • Serious Eye Damage/ Eye Irritation • Respiratory or Skin Sensitization • Germ Cell Mutagenicity • Carcinogenicity • Reproductive Toxicity

– Single Exposure – Repeated Exposure

• Aspiration • Simple Asphyxiants

18 Slide courtesy of OSHA Training Institute




Lower Flammable Limits (LFL) Relative to Occupational Exposure Limits

Chemical TLV (1) IDLH (2) LFL Acetone 500 ppm 2500 ppm

(10% of LFL) 2.5% (25,000 ppm)

Ammonia 25 ppm 300 ppm 15% (150,000 ppm)

Formaldehyde 0.75 ppm (OSHA PEL)

20 ppm 7 % 70,000 ppm)

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(1) Threshold Limit Value (TLV)- recommended standard developed by the American Conference of Governmental Industrial Hygienists (ACGIH)

(2) IDLH Immediately dangerous to life and health Lesson: A combustible gas meter does not indicate safety relative to inhalation exposures. Readings are in percent of Lower Flammable Limit (LFL), also often described as the Lower Explosive Limit

Odors – What does the nose know? This reflects initial information, not an

approved sampling method. Beware of olfactory fatigue.

Chemical TLV(1) ppm (2) Odor threshold (ppm)

Benzene 10 (OSHA PEL – 1 ppm)

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Chloroform 10 200 Formaldehyde 1 1 Sulfur dioxide 5 5 Acetone 500 40 Chlorine 1 0.001

(1) Threshold Limit Value (TLV)- recommended standard developed by the American Conference of Governmental Industrial Hygienists (ACGIH)

(2) Parts per million concentration in air (v/V - volume/Volume) 29

Occupational Exposure Standards and their Limitations

• Sources of data – Human experience – Environmental effects – Laboratory Toxicology – comparison with animal data – Comparison with similar chemicals

• Many new or limited use chemical don’t have established occupational exposure standards

• Purposes of standards – Prevention of long-term health effects – Prevention of cancer and/or reproductive effects – Prevention of acute irritation and discomfort – Some combination* 30




Occupational Exposure Standards and their Limitations

• Sources of standards – National regulatory US OSHA/European Union – Consensus – American Conference of Governmental

Industrial Hygienist Threshold Limit Values ®

• Intent – May or may not consider economic feasibility • Standards may be national/local, but scientific data

is typically international • Limitations- Individual variability and susceptibility

• Standards are not a fine line between safe and unsafe • Shortcomings in standards development, state of science and

regulatory processes

31




Occupational Exposure Standards Commonly used in the US

Permissible Exposure Limits, PELs • OSHA’s legally allowed

concentrations in the workplace • Three types:

– 8-hr TWA – PEL – Ceiling – PEL – STEL – PEL

• Tend to be chronologically dated

– Process for update is cumbersome and highly politicized

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Threshold Limit Values, TLVs • Airborne concentrations of

substance to which it is believed that nearly all workers may be repeatedly exposed, day after day, without adverse effect

• Guidelines published annually by American Conference of Governmental Industrial Hygienists (ACGIH)

• Tend to be more up-to-date and conservative

• More consistent with other national standards

Mil Standard 882 Task 207 Health Hazard Analysis (HHA) Process

Three (3) Categories of Information a. Hazard identification –name and affected system

components and processes (where it’s occurs) b. Start with chemical inventory and process description



3. Sometimes the evaluation will be quantitative (versus qualitative)

c. Severity and probability of exposures - Describe the potential acute and chronic health risks

d. Mitigation strategy for each hazard

– Describe a target mitigation strategy for each hazard based on the degree of risk reduction



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Health Hazard Analysis (HHA) Process First steps in Hazard Assessment

Step 1. Hazard identification –name Chemical inventory is the first step

Step 2. Use chemical safety data to evaluate potential risks - Affected system components: - Related impacts

Step 3. Processes Evaluation • Where material occurs • How its used • Potential for release/exposure

• Some information may be provided by Mil Std 882 Task 108 Hazardous Material Management Plan Task 201 Preliminary Hazard List

• Additional information from similar legacy systems



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Health Hazard Analysis (HHA) Process Next step in Hazard Assessment

Use the chemical inventory (i.e. Hazard identification) And hazard chemical hazard information to evaluate - Processes (where its occurs) - Affected system components - Related impacts • Some information may be provided by Mil Std 882

Task 108 Hazardous Material Management Plan Task 201 Preliminary Hazard List

• Additional information from similar legacy systems



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• Required by OSHA and EPA Regulations and common sense

• Should be part of systems engineering process

– Suggest making this a contract deliverable – Consider compatible data formats and link to user training

• Chemical safety information – Material Safety Data Sheets (MSDS) – Safety Data Sheets (SDS) being phased in – Other sources of information (see background slides) – DOD sources of information (HMIRS)

http://www.dlis.dla.mil/hmirs/

• Prevention through design where feasible – use least hazardous processes and materials compatible with effectiveness and economy

Chemical Inventory (what and where used)



Severity and probability of exposures Applies to all categories of health hazards

Chemical example used

• Basic process evaluation • Where and how exposures are likely to occur • Anticipated severity of exposures

– Initial qualitative – Quantitative, if warranted by initial assessment

• Discussion of calculating estimated airborne exposure, time permitting

37



Health Hazard Analysis (HHA) Process Mil Standard 882 Task 207



- Simple - Sometimes the evaluation will be quantitative (versus

qualitative) - More complex (many mathematical models, many

derived from the ideal gas law) - Past evaluations of similar processes

- Sources include Service Public Health Centers and NIOSH 38

39

Why Estimate Chemical Concentration and Exposures?

• Preliminary estimate of risk in initial design and development.

• Potential application to chemical process management

• Disaster evaluation and response • Background information for system safety

professionals- How to use this information – Generally safe situation (Okay-Yes) – Significant uncontrolled hazard (Not okay-stop) – Areas requiring further evaluation (Get help-Maybe)



40

Estimating chemical concentration and exposures

• Tools for estimating airborne chemical concentrations and their dispersion.

• Potential application to chemical process management – Including routine maintenance and – Predictable mishaps (disaster prevention and

response planning) • Assist system safety professionals in integrating

chemical risk management into the systems engineering process

Calculation of Chemical Concentrations

If time permits

41

Mitigation System Safety Hierarchy of Controls

Control Measure Examples Eliminate hazards through design selection

Removal of critical hazardous product (such as lead or chrome from paints); aerobic versus anaerobic digestion for waste (no H2S)

Reduce risk through design alteration

Use less hazardous materials; dip or brush paint application

Incorporate engineered features or devices

Local exhaust ventilation; process temperature controls

Provide warning devices

Temperature/pressure warning devices Gas concentration monitor

Signs, procedures, training protective equipment

Warnings, qualifications/training for use, personal protective equipment

42



Risk Evaluation May lead to mitigation strategy

• Begin with the end in mind- what is this process or operation seeking to accomplish? – Many legacy processes have used unnecessarily

hazardous material and approaches – Examples of process substitution

• Remote inspection of confined spaces (versus manned entry) • Water-based versus oil-based paints in some marine or damp

areas • Replace versus refurbish some parts • Glove box paint removal versus hand sanding

• Databases and sources of assistance – EPA Green Chemistry http://www2.epa.gov/green-

chemistry – Service public health centers and systems command

environmental directorates – Industry and trade groups

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• HHA Process • Background material • Chemical Health Hazard

Evaluation • Mitigation/control

http://www2.epa.gov/green-chemistry

http://www2.epa.gov/green-chemistry

Ventilation Basics- Factors to Consider • Lack of any ventilation in a space

• Volume of airflow • Fire and explosive safety • Health hazards • Comfort and removal of nuisance contaminants

• Source of contaminants • Specific point source –consider local exhaust • Diffuse sources – general dilution ventilation

• Direction of airflow – Will prospective contaminants be moved away from workers?

• Air balance – make up air (and its distribution) • Ventilation system design for

– Efficiency –complex duct design and/or excessive air duct velocity wastes energy

– Noise control- excessive noise may be a sign of wasted energy – Maintainability - Fire-explosive safety

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Personal Protective Equipment Considerations in Routine Use

• Need to describe operations and requirements for protective equipment in writing

• Identify alternatives to personal protective equipment to be used when feasible.

• Guidelines for routine selection and use. • Documented training in routine and emergency

use. • Limitations and liability for proper use. • Monitoring and enforcement of use. • Comfort and productivity.

• HHA Process • Background material • Chemical Health Hazard


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Comfort and productivity

A man in armor is his armor’s slave

- Robert Browning

Quoted in: Personal Protective Equipment for Hazardous Materials Incidents: A selection guide NIOSH 1984

47

Personal Protective Equipment (PPE) Considerations in Emergency Response

• Added problems of protective equipment selection and use – Uncertain exposures – Limited time for planning

• Limits of Protective Equipment

– Inhalation exposures – Skin exposures

• Added burden of PPE when performing work

– Heat stress – Discomfort – Reduced mobility, manual dexterity and visibility

•

48

Always think of skin (protection) first!

49

Early history of skin protection Early model: Water-permeable

skin prevents wandering away from the swamp.

Latter model: Non-permeable skin prevents drying out and is difficult for predators to chew.

50

Evolution of Advanced Protective Equipment

Technical problems: Additional protective equipment limits

mobility and increases heat stress. (Still can’t get away from the swamp).

51

Common materials which can create exposures via the skin

Chemical(s) Use Remarks Aniline and related dyes Dyes and stains

Diazinon Malathion

Pesticides Many pesticides absorbed via skin

Dinitrobenzene Dyes, organic synthesis

Formaldehyde Preservative Skin sensitizer

Hydroquinone Photo developer Skin sensitizer

Mercury Inorganic form in instruments

Organic forms highly toxic

Phenol Separatory media for DNA isolation, organic

synthesis, disinfectants

Nitroglycerin Ordnance, propellants Potent vasodilator, acute headaches, cardiac issues

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Gloves and other protective equipment selection

• Required part of OSHA standard for protective equipment, respiratory protection and hearing conservation – 29 CFR 1910.132

• Aspect of systems support related to training and support equipment

• Should consider permeability, protection and durability of gloves – See vendors websites such as Best Gloves – http://www.chemrest.com/

http://www.chemrest.com/

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May be well prepared for respiratory hazard

Not so well-prepared for potential skin hazards

Simplified Case Study- Extrusion of propellant for rocket manufacture

Common Sources of information include • Process review and hazardous material identification from standard

practice guides • Surveys of similar processes/operations/ work environments

• NIOSH Health Hazard Evaluations

• EPA studies conducted in collaboration with DOD (Example) Handbook on the Management of Ordnance and Explosives at Closed, Transferring, and Transferred Ranges and Other Sites • http://www.epa.gov/swerffrr/pdf/IFUXOCTTHandbook.pdf

54

Presenter

Presentation Notes

(1987) ICI Americas, Inc., Indiana Army Ammunition Plant, Charlestown, Indiana. (Click for full summary) In response to a request from the International Chemical Workers Union, a study was made of carpal tunnel syndrome, ganglionic cysts, and tendonitis of the wrists in production workers at ICI Americas Inc. ammunition facility (SIC-3483) in Charlestown, Indiana. About 1800 workers were employed in the assembly of solid propellant charges used to propel projectiles. Questionnaires were completed by 463 production workers. Workers in the assembly, lace and tie job classification had the highest pre... (Click to show more) In response to a request from the International Chemical Workers Union, a study was made of carpal tunnel syndrome, ganglionic cysts, and tendonitis of the wrists in production workers at ICI Americas Inc. ammunition facility (SIC-3483) in Charlestown, Indiana. About 1800 workers were employed in the assembly of solid propellant charges used to propel projectiles. Questionnaires were completed by 463 production workers. Workers in the assembly, lace and tie job classification had the highest prevalence of upper extremity symptoms. Ergonomic evaluations were performed on the six jobs having the highest incidence of upper extremity symptoms. Analysis of the video tapes indicated the tying of pull straps on the propellant charges to be one of the most difficult tasks performed by these workers. Movements were highly repetitive, caused awkward and forceful manipulations of the hand and wrist, and involved many factors causally related to cumulative trauma disorders. Additional problems included excessive reach distances, improper work height, and improper seated work postures. The authors conclude that this production work is associated with a high prevalence of musculoskeletal disorders. The authors recommend specific improvements in each job. Training sessions should be conducted to instruct the workers how to accomplish their given tasks with less bodily strain. All hand and wrist injuries should be reported to their employer and accurate records should be kept. Contact us to obtain a copy of report HETA-85-534-1855. http://www2a.cdc.gov/hhe/search.asp

http://www.epa.gov/swerffrr/pdf/IFUXOCTTHandbook.pdf

http://www.epa.gov/swerffrr/pdf/IFUXOCTTHandbook.pdf

HAZMAT evaluation- Identify the HAZMATs Blue Shows Mil Std 882 process

• How the HAZMAT is used for each process or

component: – Extrusion into propellants

• Additional considerations: – Temperature during casting – Clean-up of machinery

• Estimate the usage rate of each HAZMAT for each process or component: – Used to evaluate concentrations – minimize explosive

risks and also estimate airborne concentrations. • Recommend the disposition for each HAZMAT (to include

hazardous waste) identified). • Potential substitutions

55

• HHA Process (review)

• Background material • Chemical Health Hazard


Presenter

Presentation Notes

More on what’s in a hazmat evaluation (Mil Std 882- Task 207, para 207.2.3.1. Source documents, such as Material Safety Data Sheets (MSDSs), and information from vendors and sub-vendors for components of systems and subsystems Material identification includes material identity, common or trade names, chemical name, CAS number, national stock number (NSN), local stock number, physical state, and manufacturer and supplier names and contact information (including information from the Department of Defense HAZMAT information resource system). b.

Simplified Case Study- Extrusion of propellant for rocket manufacture

(Blue shows Mil Std 882 Process) • Process review and hazardous material identification from standard

practice guides: Material used and health concerns • 2,4-Dinitrotoluene C7H7N2O4 Exposure can cause

methemoglobinemia, anemia, leukopenia, liver necrosis, vertigo, fatigue, dizziness, weakness, nausea, vomiting, dyspnea, arthralgia, insomnia, tremor, paralysis, unconsciousness, chest pain, shortness of breath, palpitation, anorexia, and loss of weight.

• Immediate concerns: Explosive safety and related precautions to

prevent detonation – Least hazardous available product selected to accomplish military

objectives – Facility located at safe distance as determined by type and quantity of

ordnance – Explosion proof lighting and control of ignition sources

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• HHA Process (review) • Background material • Chemical Health


2,4-Dinitrotoluene C7H7N2O4

Physical state and appearance: • Yellow crystals with characteristic odor Physical danger: • Dust explosion possible if in powder or granular form, mixed with air. Chemical dangers: • May explode on heating. The substance decomposes on heating

producing toxic and corrosive fumes including nitrogen oxides even in absence of air. Reacts with strong bases, oxidants and reducing agents.

Occupational Exposure Limits (OELs): • TLV: ppm; 0.2 mg/m3 (as TWA) (skin) (ACGIH 2013). Routes of Exposure: The substance can be absorbed into the body by • Inhalation, • Through the skin • Ingestion.

57

2,4-Dinitrotoluene C7H7N2O4 CAS # 121-14-2 Inhalation risk:

• Evaporation at 20°C is negligible; a harmful concentration of airborne particles can, however, be reached quickly.

Effects of short-term exposure: • The substance irritates the eyes and the skin. The substance may

cause effects on the central nervous system, cardiovascular system, and the blood , resulting in the formation of methaemoglobin. The effects may be delayed.

Effects of long-term exposure or repeated exposures: • The substance may effect the central nervous system, cardiovascular

system and blood , resulting in formation of methaemoglobin.

Information Source: International chemical safety cards http://hazard.com/msds/mf/cards/file/0727.html 58

http://hazard.com/msds/mf/cards/file/0727.html

Methemoglobin • Methemoglobin (British English: methaemoglobin) (pronounced "met-

hemoglobin") is a form of the oxygen-carrying metalloprotein hemoglobin, in which the iron in the heme group is in the Fe3+ (ferric) state, not the Fe2+ (ferrous) of normal hemoglobin. Methemoglobin cannot bind oxygen, unlike oxyhemoglobin.[2] It is bluish chocolate-brown in color. In human blood a trace amount of methemoglobin is normally produced spontaneously. But when it is present in excess the blood becomes abnormally dark bluish brown. The NADH-dependent enzyme methemoglobin reductase (diaphorase I) is responsible for converting methemoglobin back to hemoglobin.

• Normally one to two percent of a person's hemoglobin is methemoglobin; a higher percentage than this can be genetic or caused by exposure to various chemicals and depending on the level can cause health problems known as methemoglobinemia.

59 http://en.wikipedia.org/wiki/Methemoglobin

http://en.wikipedia.org/wiki/Methemoglobin






Some additional considerations

• Temperature of material • Ventilation

– Volume and direction of airflow • Skin protection –

– Approaches to minimize manual contact • Ordnance manufacture is a repetitive

process – Evaluate the potential for ergonomic issues

and repetitive motion disorders 60

• HHA Process (review) • Background material • Chemical Health


Summary Chemical risk assessment considers

– Materials • Composition and chemical properties • Hazardous constituents and their potential health and safety

impacts • Potential substitutes, if appropriate

– Process description – Risks during routine use, maintenance, realistic

minors “spills”, emergency scenarios – Control measures using the hierarchy of controls;

• substitution/ elimination; • containment/control; • procedures and training; • protective equipment (consider limitations)

61

Break

• Please return at 10:30

• Next – Noise, the most prevalent health hazard – Class exercises in health hazard evaluation

• Also available in class handouts – Calculations of solvent and compressed gas

concentrations (time permitting) – Other sources of information

62

Additional Resources

63

Presenter

Presentation Notes

Update on Scorecard Scorecard is now back in the hands of the team that first created this service in 1998 while they were working for the Environmental Defense Fund. We are currently working on updating the site's chemical profiles and health hazards information and are about to begin a comprehensive update of the site's environmental data. Scorecard is sponsored by GoodGuide, the world's largest and most reliable source of information on the health, environmental, and social impacts of consumer products. If you want to find products that are healthy, green and socially responsible, support us by downloading our transparency toolbar or our mobile applications. Bill Pease, Ph.D. Chief Scientist GoodGuide [email protected]

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• Merck Index • Clinical Toxicology of Commercial Products • Chemical Hazards in the Workplace (Proctor and

Hughes) • Sigma Aldrich Library of Chemical Safety Data • Physicians Desk Reference (for drugs) • Hazardous Chemicals Desk Reference (Lewis) • Emergency Care for Hazardous Materials Exposure

(Bronstein and Currance)

Additional Library Resources

65

• EPA Chemical References http://www.epa.gov/enviro/html/emci/chemref • ChemView http://java.epa.gov/chemview • Allows comparative evaluation of materials and public access

to varied data sources. • Read the manual! • http://java.epa.gov/chemview/resources/ChemView%20Public

%20UI%20Guide.pdf • MSHA Link to MSDS sites http://www.msha.gov/MSDS.HTM

• OSHA/EPA Occupational Chemical Database.

https://www.osha.gov/chemicaldata/

• CAMEO Chemicals An online hazardous material database

http://response.restoration.noaa.gov/cameochemicals

Internet Resources

http://www.epa.gov/enviro/html/emci/chemref

http://java.epa.gov/chemview/resources/ChemView Public UI Guide.pdf









http://www.msha.gov/MSDS.HTM





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More Resources

• NIOSH Pocket Guide to Chemical Hazards • http://www.cdc.gov/niosh/npg/default.html • OSHA Annotated PELs • Also contains other reference guidance • https://www.osha.gov/dsg/annotated-pels/tablez-2.html

• ACGIH® 2014 Threshold Limit Values for Chemical Substances in

the Work Environment. Adopted by ACGIH® with Intended Changes. See http://www.acgih.org/.

• The Globally Harmonized System for Hazard Communication • https://www.osha.gov/dsg/hazcom/global.html

http://www.cdc.gov/niosh/npg/default.html

https://www.osha.gov/dsg/annotated-pels/tablez-2.html





http://www.acgih.org/

https://www.osha.gov/dsg/hazcom/global.html

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• Primarily for transportation accidents

• Cross reference – UN Numbers – Common names – Standard response

guides – Evacuation distances

North American Emergency Response Guidebook

http://phmsa.dot.gov/hazmat/library/erg

http://phmsa.dot.gov/hazmat/library/erg

Navy Marine Corps Public Health Center http://www.med.navy.mil/sites/nmcphc/industrial-hygiene/Pages/Industrial-Hygiene-Topics.aspx

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Chemical Stressors Chemical Stressor Dictionary with Occupational Exposure Limits and Other Information and Notations- Quick reference for determining current occupational exposure limits and information such as carcinogenicity classification, reproductive notations, and skin notations, for specific chemical stressors of industrial hygiene interest. Chemical Stressors List with Medical Surveillance and BEI Information and Skin Notation–Reference for determining the medical surveillance procedure requirements for chemical stressors. It also provides a listing of chemicals that fall under specific medical surveillance programs (Medical Matrix Number). Emerging Contaminants Program Emerging contaminants (EC) are defined by the Department of Defense (DoD) as chemicals or materials that either lack published health standards, have an evolving regulatory or science status or pose a threat to human health or the environment with the potential to impact mission readiness. The program is managed under the Assistant Deputy Under Secretary of Defense for Environment, Safety and Occupational Health as delineated in DoD Instruction 4715.18, Emerging Contaminants (EC). As an active member of the Chemical and Material Risk Management Directorate’s Materials of Evolving Regulatory Interest Team (MERIT),

http://www.med.navy.mil/sites/nmcphc/industrial-hygiene/Pages/Industrial-Hygiene-Topics.aspx

http://www.med.navy.mil/sites/nmcphc/Documents/industrial-hygiene/Stressor-Dictionary.xlsx

http://www.med.navy.mil/sites/nmcphc/Documents/industrial-hygiene/Stressor-Dictionary.xlsx

http://www.med.navy.mil/sites/nmcphc/Documents/industrial-hygiene/Chemical-Stressors-List-for-BEI.xlsx

http://www.med.navy.mil/sites/nmcphc/Documents/industrial-hygiene/Chemical-Stressors-List-for-BEI.xlsx

http://www.dtic.mil/whs/directives/corres/pdf/471518p.pdf

http://www.dtic.mil/whs/directives/corres/pdf/471518p.pdf

https://www.denix.osd.mil/cmrmd/



Additional Resources • Scorecard • Cancer references • http://scorecard.goodguide.com/health-

effects/references.tcl?short_hazard_name=cancer

69

Presenter

Presentation Notes

Update on Scorecard Scorecard is now back in the hands of the team that first created this service in 1998 while they were working for the Environmental Defense Fund. We are currently working on updating the site's chemical profiles and health hazards information and are about to begin a comprehensive update of the site's environmental data. Scorecard is sponsored by GoodGuide, the world's largest and most reliable source of information on the health, environmental, and social impacts of consumer products. If you want to find products that are healthy, green and socially responsible, support us by downloading our transparency toolbar or our mobile applications. Bill Pease, Ph.D. Chief Scientist GoodGuide [email protected]

Back-up slides

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• Chemical inventory • Terms (review) • Emergency Response

Guide • Material Safety Data

Sheets (MSDS) • Safety Data Sheet (SDS) • Other Chemical Safety

information

Routine and emergency access to chemical safety information




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• Consider integration into systems engineering and documentation

• Emergency response guidelines • Pocket References

– NIOSH pocket guide – DOT Guide – Emergency Handling of Hazardous

Materials (OSH office) • Material safety data sheets MSDS)/ • Safety Data Sheets (SDS)

– Vary widely in usefulness – May need to develop summary information – DOD databases

Sources for locating chemical safety information

• OSHA is retaining the requirement to include the American Conference of Government Industrial Hygienists (ACGIH) Threshold Limit Values (TLVs) on the safety data sheet (SDS) in the revised Standard. OSHA finds that requiring TLVs on the SDS will provide employers and employees with useful information to help them assess the hazards presented by their workplaces. In addition to TLVs, OSHA permissible exposure limits (PELs), and any other exposure limit used or recommended by the chemical manufacturer, importer, or employer preparing the safety data sheet are also required.

73

Occupational Exposure Standards on Safety Data Sheets

74

Background Information

• Conversions, spills and other yucky stuff – Common conversions – Ideal gas law (college chemistry)

• Sources of information on chemical compatibility – Prevention - How to keep things from going

wrong – Mishap evaluation - How to figure our what

might have gone wrong (after the fact)

75

Conversions Avoid Mars Polar Lander Type Impacts

• Metric English (SAE) • Mass Moles Vapor volume

Concentration (in a given volume) • Logarithms Linear (exponential

relations) • Handy conversion factors

•http://www.greatdreams.com/lander.htm

Presenter

Presentation Notes

ENGINE CUTOFF DOOMED POLAR LANDER NASA's Mars Polar Lander probably failed due to a premature shutdown of its descent engine, causing the $165 million spacecraft to smash into the surface of Mars, according to new information released Tuesday. http://www.space.com/cgi-bin/email/gate.cgi?lk=T1&date=000328&go=/science/solarsystem/mpl_report_000328.html

http://www.greatdreams.com/lander.htm

76

Some useful conversion factors

Metric English

28.3 liters 1 cubic foot(a little more than 1 mole ofgas at STPD)

3.785 liters 1 gallon

1 kg 2.2 pounds

77

Sample conversion problem

• How much does a gallon of acetone weigh? • 1 gallon (water) x 0.79 density (acetone/water) x 3.78 liters/gallon x 1.0 kg/liter x 2.2 pounds/gallon = = 6.57 lb./gallon acetone • 1 gallon water x 3.78 liters/gallon x 1.0 kg/liter x 2.2 density pounds/kg = 8.32 lb./gallon of water

Math check • 1 gallon of acetone weighs 6.57 pounds (2.99 kg) = 0.79 • 1 gallon of water weighs 8.32 lb. (3.78 kg)

78

Sample problem: Boyles Law Application

• A smelter is to be located at 8000 feet altitude.

• Find the volume correction if the pressure is 650 mmHg (versus 760 mmHg at sea level)

• The fan used to exhaust contaminant is sized for 10,000 cfm.

• How large a fan will this location require?

79


• PV=Constant or P1V1=P2V2

P1V1 = P2V2

• V2 =P1V1/P2

• V2 = 760 mmHg x 10000 cfm/650 mmHg =

• V2 = 11692 cfm

Ground level - higher pressure, lower volume

Altitude- lower pressure,

greater volume

http://images.google.com/imgres?imgurl=http://www.glasspaintingsoflondon.com/ballthnl.jpg&imgrefurl=http://www.glasspaintingsoflondon.com/morepics.html&h=150&w=100&sz=9&hl=en&start=28&sig2=NRgbUTmawC35u2Pf3drFbA&tbnid=s6Q6RjdMookfJM:&tbnh=96&tbnw=64&ei=k5KkRpD5NZeoeLv_tTI&prev=/images?q=french+balloon&start=20&gbv=2&ndsp=20&svnum=10&hl=en&sa=N

80


• How much nitrogen will a 10 cubic foot cylinder hold if the pressure is increased to 2200 psig? (standard for a compressed gas cylinder).

• Normal atmospheric pressure is 14.7 psig.

• Could this form an asphyxiating mixture if

released into an un-ventilated room 10 feet x 12 feet x 8 feet?

(Combustible range in air is between 4% and 75% by volume; Explosive range 18.3 to 59 %).

Presenter

Presentation Notes

Hydrogen Safety http://en.wikipedia.org/wiki/Hydrogen_safety Ignition[edit]Main article: Minimum Ignition Energy "Hydrogen-air mixtures can ignite with very low energy input, 1/10 that required igniting a gasoline-air mixture. For reference, an invisible spark or a static spark from a person can cause ignition." "Although the auto ignition temperature of hydrogen is higher than those for most hydrocarbons, hydrogen's lower ignition energy makes the ignition of hydrogen–air mixtures more likely. The minimum energy for spark ignition at atmospheric pressure is about 0.02 millijoules." Mixtures[edit]"The flammability limits based on the volume percent of hydrogen in air at 14.7 psia (1 atm, 101 kPa) are 4.0 and 75.0. The flammability limits based on the volume percent of hydrogen in oxygen at 14.7 psia (1 atm, 101 kPa) are 4.0 and 94.0." "The limits of detonability of hydrogen in air are 18.3 to 59 percent by volume"[4] "Flames in and around a collection of pipes or structures can create turbulence that causes a deflagration to evolve into a detonation, even in the absence of gross confinement." (For comparison: Deflagration limit of gasoline in air: 1.4–7.6%; of acetylene in air,[5] 2.5% to 82%) Leaks[edit]Leakage, diffusion, and buoyancy: These hazards result from the difficulty in containing hydrogen. Hydrogen diffuses extensively, and when a liquid spill or large gas release occurs, a combustible mixture can form over a considerable distance from the spill location. Hydrogen, in both the liquid and gaseous states, is particularly subject to leakage because of its low viscosity and low molecular weight (leakage is inversely proportional to viscosity). Because of its low viscosity alone, the leakage rate of liquid hydrogen is roughly 100 times that of JP-4 fuel, 50 times that of water, and 10 times that of liquid nitrogen. Hydrogen leaks can support combustion at very low flow rates, as low as 4 micrograms/s.[6]

81

Sample problem: Boyles Law Application • PV = constant* or P1V1=P2V2

* (at constant temperature) • Normal atmospheric pressure is 14.7 psi. V2=P1V1/ P2 = 2200 psi x 10 cf/14.7 psi V2=1497 cf Nitrogen conc. =1497 cf/[10 ft. x 12 ft. x 8 ft.] 1497 cf Nitrogen /960 cf room size Nitrogen conc. = 1.5* >> 0.04 (4%) This is enough to occupy to room volume 1 ½ times Room size 10 feet x 12 feet x 8 feet

Presenter

Presentation Notes

Obvious comment: If an explosively rapid release such as a tank rupture occurred, the explosion would create a significant hazard including flying objects. Conclusion: If a slow leak developed during a relatively short time with limited ventilation, the concentration could rise to a level of significant concern. If there was very limited or no ventilation, such a leak could create an un-breathable atmosphere by displacing the normal oxygen-containing atmosphere.

82

Now a more exciting variant- Hydrogen Sample problem: Boyles Law Application

• PV = constant* or P1V1=P2V2 * (at constant temperature) • Normal atmospheric pressure is 14.7 psi. V2=P1V1/ P2 = 2200 psi x 10 cf/14.7 psi V2=1497 cf hydrogen conc. =1497 cf/[10 ft. x 12 ft. x 8 ft.] 1497 cf hydrogen/960 cf room size Hydrogen conc. = 1.5* >> 0.04 (4%) This is enough to occupy to room volume 1 ½ times Room size 10 feet x 12 feet x 8 feet Hydrogen Lower explosive limit, LEL, is 4%

Presenter

Presentation Notes

Obvious comment: If an explosively rapid release such as a tank rupture occurred, the explosion would create a significant hazard including flying objects. Conclusion: If a slow leak developed during a relatively short time with limited ventilation, the concentration could rise to a level of significant concern. If there was very limited or no ventilation, such a leak could create an un-breathable atmosphere by displacing the normal oxygen-containing atmosphere.

83

Charles Law: Correction for Temperature

• The same cylinder may be subjected to increased pressure as a result of heat.

• The sprinklers are activated at 121 oC (250 oF). • Will this prevent rupture?

• If rupture disks are designed to give way

at 3000 psi, what temperature will this represent?

Presenter

Presentation Notes

[250 of – 32 ]x (5 oC/9 oF) = 121 oC

84

Portable Compressed Gas Cylinder Safety Web page for the health and safety of everyone on campus, presented by The University of Texas Health Science Center at Houston Safety Council and the Office of Institutional Advancement

Remainder of the nitrogen gas cylinder after it exploded. Laboratory damage resulting

from a gas cylinder explosion.

Presenter

Presentation Notes

publicaffairs.uth.tmc.edu/safety1st/archive/g...

Other Issues and Thoughts • Should electrical equipment be explosion proof?

– Always consult NFPA and other codes.

• Effectiveness of room ventilation

• Could a smaller cylinder be used?

• For remotely located/confined areas consider – Locating the tank outside the space and having gas

piped in – Use of a smaller tank

85

86

Charles Law: Correction for Temperature (continued)

• V/T = constant (at unchanging pressure)

• V1/T1 = V2/T2 If external pressure is constant – T2= V2 T1 /V1= [273+121]x3000psi/2200psi – T2 = 394 oKx3000psi/2200psi =537 oK

• Temperature 0C: 537 oK-273 = 264 0C • Temperature 0F: 264 0C x 9/5 oF/oC + 32oF = 507 0F

• Conclusion: Sprinklers will go off before rupture disks

burst. • Note that “real” fire prevention calculations may be a little

more complicated.

87

Sample Problem: Avogadro’s Number

• V = n x Constant • V= volume, n= moles of gas • At standard temperature and pressure (25 0C, 298 0K) Volume of a gas is proportional to the number of molecules (regardless of the

type or molecular weight of the gas)

Avogadro’s constant = 1 mole ~ 6.023 x (10)23 molecules At STPD one mole of gas occupies about 24.45 liters Hydrogen H2 (MW =1.008) or Oxygen O2 (MW = 32.00)

would occupy the same volume (24.45 liters ~0.86 cubic feet)

Presenter

Presentation Notes

Avogadro constant From Wikipedia, the free encyclopedia http://en.wikipedia.org/wiki/Avogadro_constant Jump to: navigation, search The Avogadro constant (symbols: L, NA), also called the Avogadro number and, in German scientific literature, sometimes also known as the Loschmidt constant/number, is formally defined to be the number of "entities" in one mole,[1][2] that is the number of carbon-12 atoms in 12 grams (0.012 kg) of unbound carbon-12 in its ground state. The current best estimate of this number is [3]: Contents [hide] History and terminology Application Additional physical relations Measurement of the Avogadro constant See also References and notes External links [edit] History and terminology The Avogadro constant is named after the early nineteenth century Italian scientist Amedeo Avogadro, who is credited with being the first to realize that the volume of a gas (strictly, of an ideal gas) is proportional to the number of atoms or molecules. The French chemist Jean Baptiste Perrin in 1909 proposed naming the constant in honor of Avogadro. American chemistry textbooks picked it up in the 1930's followed by high school textbooks starting in the 1950s.[4] Avogadro never attempted to measure the constant: the numerical value was first estimated by the Austrian physicist Johann Josef Loschmidt in 1865 using the kinetic theory of gases.[5] In German-speaking countries, the constant may still be referred to as the Loschmidt constant or Loschmidt's number: However this name is more correctly reserved for the number of particles in a given volume of an ideal gas (symbol:n0):[6] equal to (2.686 7773 ± 0.000 0047)×1025 m−3 at 273.15 K and 101.325 kPa with R the gas constant, T the temperature and p the pressure. This constant is related to the Avogadro constant by the relation: with kB the Boltzmann constant hence The connection with Loschmidt is the explanation for the symbol L, often used instead of NA to refer to the Avogadro constant. Before 1960, there were conflicting definitions of the mole, and hence of the Avogadro number (as it was known at the time), based on 16 grams of oxygen: physicists generally used oxygen-16 while chemists generally used the "naturally occurring" isotope ratio. Switching to 12 grams of carbon-12 as the basis ended this dispute and had other advantages.[7] At this time, the Avogadro number was defined as the number of atoms in 12 grams of carbon-12, that is as a dimensionless quantity, while a mole was defined as one Avogadro number of atoms, molecules or other entities. When the mole entered the International System of Units (SI) in 1971 as the base unit of amount of substance, the definitions were interchanged: what had previously been a number became a physical constant with the unit of reciprocal moles (mol−1). The genitive form "Avogadro's constant (number)" is often used but not recommended, particularly as Avogadro never attempted to measure the constant himself.[8] [edit] Application The Avogadro constant can be applied to any substance. It corresponds to the number of atoms or molecules needed to make up a mass equal to the substance's atomic or molecular mass, in grams. For example, the atomic mass of iron is 55.847 g/mol, so NA iron atoms (i.e. one mole of iron atoms) have a mass of 55.847 g. Conversely, 55.847 g of iron contains NA iron atoms. The Avogadro constant also enters into the definition of the unified atomic mass unit, u: [edit] Additional physical relations Because of its role as a scaling factor, the Avogadro number provides the link between a number of useful physical constants when moving between the atomic scale and the macroscopic scale. For example, it provides the relationship between: the gas constant R and the Boltzmann constant kB: in J mol−1 K−1 the Faraday constant F and the elementary charge e: in C mol−1 [edit] Measurement of the Avogadro constant A number of methods can be used to measure the Avogadro constant. One modern method is to calculate the Avogadro constant from the density (ρ) of a crystal, the relative atomic mass (M), and the unit cell length (a) determined from x-ray crystallography. Very accurate values of these quantities for silicon have been measured at the National Institute of Standards and Technology (NIST) and used to obtain the value of the Avogadro constant: based on silicon. [edit] See also Mole (unit) Large numbers [edit] References and notes ^ International Union of Pure and Applied Chemistry Commission on Physicochemical Symbols Terminology and Units (1993). Quantities, Units and Symbols in Physical Chemistry (2nd Edition). Oxford: Blackwell Scientific Publications. ISBN 0-632-03583-8. Retrieved on 2006-12-28. International Union of Pure and Applied Chemistry Commission on Quantities and Units in Clinical Chemistry; International Federation of Clinical Chemistry Committee on Quantities and Units (1996). "Glossary of Terms in Quantities and Units in Clinical Chemistry (IUPAC-IFCC Recommendations 1996)". Pure Appl. Chem. 68: 957–1000. ^ International Union of Pure and Applied Chemistry Commission on Atomic Weights and Isotopic Abundances (1992). "Atomic Weight: The Name, Its History, Definition and Units". Pure Appl. Chem. 64: 1535–43. Retrieved on 2006-12-28. ^ CODATA (2006). ^ How and When Did Avogadro's Name become Associated with Avogadro's Number? Jensen, William B. J. Chem. Educ. 2007 84 223. Link ^ Bader, Alfred; Parker, Leonard. "Joseph Loschmidt, Physicist and Chemist". Physics Today Online (March 2001). Retrieved on 2006-12-28. ^ National Institute of Standards and Technology (February 2006). Fundamental physical constants: Physico-chemical constants. Retrieved on 2006-12-28. ^ Bureau international des poids et measures (March 2006). Unit of amount of substance (mole). Retrieved on 2006-12-28. ^ Had Avogadro been able to measure the Avogadro constant, he would have determined a value approximately half of that used today, as relative atomic masses at that time were determined on a scale of H2 = 1. In fact Avogadro's proposal, which implied atoms and molecules had a physical, measurable existence, was not widely accepted until after his death. See Amadeo Avogadro. [edit] External links 1996 definition of the Avogadro constant from the IUPAC Compendium of Chemical Terminology ("Gold Book") Some Notes on Avogadro's Number, 6.022×1023 (historical notes) An Exact Value for Avogadro's Number -- American Scientist Retrieved from "http://en.wikipedia.org/wiki/Avogadro constant" Categories: Chemical nomenclature | Physical constants Views Article Discussion Edit this page History Personal tools Sign in / create account Navigation Main page Contents Featured content Current events Random article interaction About Wikipedia Community portal Recent changes File upload wizard Contact Wikipedia Make a donation Help Search Toolbox What links here Related changes Upload file Special pages Printable version Permanent link Cite this article This page was last modified 02:22, 23 June 2007. All text is available under the terms of the GNU Free Documentation License. (See Copyrights for details.) �Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc., a US-registered 501(c)(3) tax-deductible nonprofit charity.� Privacy policy About Wikipedia Disclaimers

88

Ideal Gas Law

• N = number of moles • T = Temperature (absolute temperature in

Kelvin or Rankin) • P = Pressure (absolute pressure) • V = Volume • R = gas constant (depends on units used)

Presenter

Presentation Notes

Ideal gas law From Wikipedia, the free encyclopedia http://en.wikipedia.org/wiki/Ideal_gas_law The ideal gas law is the equation of state of a hypothetical ideal gas, first stated by Benoît Paul Émile Clapeyron in 1834. The state of an amount of gas is determined by its pressure, volume, and temperature according to the equation: where is the absolute pressure [Pa], is the volume [m3] of the vessel containing moles of gas, is the amount of substance of gas [mol], is the gas constant [8.314 472 m3·Pa·K−1·mol−1], is the temperature in kelvin [K]. The ideal gas constant (R) depends on the units used in the formula. The value given above, 8.314472, is for the SI units of pascal cubic meters per mole per kelvin, which is equal to joule per mole per degree kelvin (J mol-1 K-1). Another value for R is 0.082057 L·atm·mol−1·K−1) "R" has a different value for each different unit of pressure used. The values are... R = 8.314472 (pascals/kPa) R = .0821 (atms) R = 62.4 (torr/mmHg) R = 1.2 (psi) The ideal gas law is the most accurate for monoatomic gases at high temperatures and low pressures. This follows because the law neglects the size of the gas molecules and the intermolecular attractions. Obviously the neglect of molecular size becomes less important for larger volumes, i.e., for lower pressures. The relative importance of intermolecular attractions diminishes with increasing thermal kinetic energy 3kT/2, i.e., with increasing temperatures. The more accurate Van der Waals equation takes into consideration molecular size and attraction. The ideal gas law mathematically follows from statistical mechanics of primitive identical particles (point particles without internal structure) which do not interact, but exchange momentum (and hence kinetic energy) in elastic collisions. Alternative forms Considering that the amount of substance could be given in mass instead of moles, sometimes an alternative form of the ideal gas law is useful. The number of moles ( ) is equal to the mass ( ) divided by the molar mass ( ): Then, replacing gives: from where . This form of the ideal gas law is particularly useful because it links pressure, density ρ = m / V, and temperature in a unique formula independent from the quantity of the considered gas. In statistical mechanics the following molecular equation is derived from first principles: Here is Boltzmann's constant, and is the actual number of molecules, in contrast to the other formulation, which uses , the number of moles. This relation implies that , and the consistency of this result with experiment is a good check on the principles of statistical mechanics. From here we can notice that for an average particle mass of μ times the atomic mass constant mu (i.e., the mass is μ u) and since ρ = m / V, we find that the ideal gas law can be re-written as: [edit] Proof [edit] Empirical The ideal gas law can be proved using Boyle's law, Charles's law, and Gay-Lussac's law. Consider one mole of gas. Let its initial state be defined as: volume = v0 pressure = p0 temperature = t0 If this gas now undergoes an isobaric process, its state will change: volume: pressure temperature . If it then undergoes an isothermal process: where p = final pressure v = final volume T = final temperature (= t') So: ; where , termed R, is the universal gas constant. Using this notation we get: And multiplying both sides of the equation by n (numbers of moles): Using the symbol as a shorthand for (volume of moles) we get: [edit] Theoretical The ideal gas law can also be derived from first principles using the kinetic theory of gases, in which several simplifying assumptions are made, chief among which are that the molecules, or atoms, of the gas are monatomic point masses, possessing mass but no significant volume, and undergo only elastic collisions with each other and the sides of the container in which both linear momentum and kinetic energy are conserved. [edit] Derivation from the statistical mechanics Let q = (qx, qy, qz) and p = (px, py, pz) denote the position vector and momentum vector of a particle of an ideal gas, respectively, and let F denote the net force on that particle, then where the first equality is Newton's second law, and the second line uses Hamilton's equations and the equipartition theorem. Summing over a system of N particles yields �By Newton's third law and the ideal gas assumption, the net force on the system is the force applied by the walls of their container, and this force is given by the pressure P of the gas. Hence where dS is the infinitesimal area element along the walls of the container. Since the divergence of the position vector q is the divergence theorem implies that where dV is an infinitesimal volume within the container and V is the total volume of the container. Putting these equalities together yields which immediately implies the ideal gas law for N particles: where n=N/NA is the number of moles of gas and R=NAkB is the gas constant.

89

Ideal Gas Law

• PV = nRT • V = nRT/P • V = 24.45liters @ STPD

• v/Vroom = n(moles)25/V

room

– P= pressure – V= volume – n= number of moles – R=gas constant – T= temp. (Kelvin)

Limitations • Volatility/rate of

evaporation • Ventilation • Direction of airflow • Position of worker • Skin absorption • Non-linear

properties of some gases (CO2)

90

Sample calculation using ideal gas law to predict solvent exposure

• One liter of acetone* spills within a room 6 m x 8 m x 3 m

(Approximately 20 feet x 25 feet x 10 foot ceiling)

• Assuming rapid and complete evaporation, what will the maximum airborne concentration be?

* Volatile solvent previously used in nail polish remover and many ordnance operations.

* Update provided by Dr. Simmons: Current formulations of nail polish remover use ethyl acetate mixed with isopropanol. http://www.cutexnails.com/nail-care-products/no-spill-pump/ingredients

Presenter

Presentation Notes

Update provided by Dr. Simmons: Current formulations of nail polish remover use ethyl acetate mixed with isopropanol. Some more advanced formulations See Cutex website: http://www.cutexnails.com/nail-care-products/no-spill-pump/ingredients Regular Formula: Acetone, Propylene Carbonate, Aqua, Dimethyl Glutarate, Dimethyl Adipate, Dimethyl Succinate, Glycerin, Fragrance, Denatonium Benzoate, Benzophenone-1, Gelatin, FD&C Yellow 11. Non-Acetone Formula: Ethyl Acetate, Ethyl Alcohol, Aqua, Glycerin, Sodium Acetate, Fragrance, Denatonium Benzoate, Gelatin, FD&C Red 17, FD&C Yellow 11. Advanced Formula: Acetone, Deionized Water, Flaxseed Oil, Black Currant Oil, fragrance, Apricot Kernel Oil, Denatonium Benzoatem, FD&C Yellow 11, FD&C Blue 1, FD&C Red 4.

http://www.cutexnails.com/nail-care-products/no-spill-pump/ingredients

http://www.cutexnails.com/nail-care-products/no-spill-pump/ingredients

91


• V(solvent vapor) = n x 24.45 l/mole * • V(solvent vapor) = 1 liter x 790 g/liter x 1mole/44 gram x 24.45 liter/mole

v (solvent vapor) = 439 liters = 0.00305 = 0.3% V (Volume of room) = 6 m x 8 m x 3 m = 144 m3x

1000l/m3

v/V = 439 liters = 0.3%= 3050 ppm 140,000 liters

v/V = 0.00305 x 106 = 3049 ppm>>750 ppm* *(occupational exposure limit)

x [ 106 for ppm conversion]

Presenter

Presentation Notes

The bad news – solvent concentration is much greater than occupational exposure standard. The good news – solvent concentration below lower explosive limit 1%

92


V(solvent vapor) = 439 liters = 0.00305v/V = 0.3% V (room)* = 144000 liters = 0.00305 = 0.3% = 3049 parts per million (ppm) ** >> 500 ppm (Threshold Limit Value) >> 750 ppm Short-term exposure limit (STEL) (15 minutes) *V (Volume of room) = 144 m3x 1000l/m3

– 0.00305 x 106 = 3049 ppm>>500 ppm (occupational exposure limit)

** x [ 106 for ppm conversion] • The bad news – solvent concentration is much

greater than occupational exposure standard. • The good news – solvent concentration is below the

lower explosive limit 1% • Caution – you would need to apply a safety factor of

4 to 10 depending on your level of caution and extent air mixing

Presenter

Presentation Notes

The bad news – solvent concentration is much greater than occupational exposure standard. The good news – solvent concentration below lower explosive limit 1%

93

Gas Laws - Summary and Applications Boyle’s Law PV=

Constant

The volume of a gas at fixed temperature is inversely proportional to the pressure

Correction for volume if pressure changes

Charles' Law V/T = constant

Volume of a gas at constant pressure is proportional to the temperature

Correction for gas volume with temperature

Avogadro's Law

V = constant x n

Volume of a gas at constant pressure and temperature is proportional to the number of moles of gas

Calculate number of moles of a substance to estimate volume and/or concentration in a given space

Ideal gas law PV=nRT Volume occupied and pressure exerted by a gas is related to heat energy

Calculate gas concentration based on number of moles present.

94

Calculation of maximum concentrations

• Can combustion of an Acrylon® carpet produce a lethal dose of hydrogen cyanide?

• Step 1 Find the fraction of HCN by mass, Acrylon® has an empirical formula of polymer (polyacrylonitrile) – Polymer (C3H3N)x

– Monomer Empirical formula C3H3N – Structural formula CH2=CH-CN

• Step 2 Identify the dose level of concern

– You are told that a lethal dose of hydrogen cyanide is 300 mg HCN/Kg air when inhaled

– If this was the lecture on toxicology or a real-life problem, you might have to find this data independently

95

Can combustion of an Acrylon® carpet produce a lethal dose of hydrogen cyanide?

• Step 3 Find the dimensions of concern and the concentration of Acrylon® in the carpet.

• [i.e. composition and quantity of reactive precursor material] – The room is 12 x 15 x 8 feet – The carpet measures 12 x 15 feet and contains 30 oz. of Acrylon®

per square yard – Assume that the yield of HCN is 20% and that the carpet is 50%

consumed

Presenter

Presentation Notes

Prior notes : The density of air is 0.0018 grams/cm3 at 26 0C Corrected Check re density of air 24.45 liters/mole @STPD x 1M3/1000 Liters *[28 g MoleN2 x0.79 + 32 g O2 mole x 0.21] ~ 0.71 g/M3 air 1 m3/1000 liters x 1/24.45 liters/mole @STPD *[28 g MoleN2 x0.79 + 32 g O2 mole x 0.21] =1.19 g/m3

96

Molecular weight calculations Element Atomic

Weight Number of atoms

Mass

C 12 X 3 = 36 H 1 X 3 = 3 N 14 x 1 = 14

Molecular weight of CH2CHCN ∑ 53 C 12 X 1 = 12 H 1 X 1 = 1 N 14 x 1 = 14

Molecular weight of HCN ∑ 27

97

Molecular weight calculations

Molecular weight of HCN = 27 = 0.509 Molecular weight of CH2CHCN 53 Bad news Up to 51% HCN by weight of Acrylon® may be released if

the carpet is entirely consumed Good news (this is just a calculation) Actual reaction yield is likely to be well below 100%

Presenter

Presentation Notes

Molecular weight of HCN27 Molecular weight of CH2CHCN53

98

Estimate the amount of hydrogen cyanide potentially formed

0.509g HCN x 3 yd. x 5 yd. x 30 oz. Acryl on® x 0.5 faction consumed 1.000g CH2CHCN =0.509 x 15 yd. x 30 oz. x 28.4 g/oz.* = 6505 g = 6.5 kg HCN released in room Density of air is 1900 g/m3*

Room size = 12ft x 15 ft. x 8 ft. =1440 ft3

1440 ft3 x 1 m3/28.4 cu = 50.70 m3 (53.3 yd3)

6505 g HCN = 241 g HCN/M3 air = 90.1 g HCN/m3 air**

1900 g/M3 air x 50.7 M3 >> 300 mg HCN/kg air IDLH = 50 ppm ~ 47 mg/m3 TLV = 5 mg/m3 (1.9 kg/M3 air x 38 M3)/ 1 kg/1000 g • See notes for conversions • ** Actual yield likely to be only 20% 18 g HCN/m3 air “only” 18000 mg/m3

Presenter

Presentation Notes

2.2 kg/1 lb. x 1000 g/kg x 32 oz./lb. = 28.4 g/oz. Check re density of air 1M3/1000 Liters /24.45 liters/mole @STPD x *[28 g MoleN2 x0.79 + 32 g O2 mole x 0.21] ~ 1.9 g/M3 air (0.0019 g/cc)

99

Estimate the amount of hydrogen cyanide potentially formed

0.509g HCN x 3 yd. x 5 yd. x 30 oz. Acryl on® x 0.5 faction consumed 1.000g CH2CHCN =0.509 x 15 yd. x 30 oz. x 28.4 g/oz.* = 6505 g = 6.5 kg HCN released in room Density of air is 1900 g/m3*

Room size = 12ft x 15 ft. x 8 ft. =1440 ft3

1440 ft3 x 1 m3/28.4 cu = 50.70 m3 (53.3 yd3)

6505 g HCN = 241 128 g HCN/M3 air = 90.1 g HCN/m3 air**

1900 g/M3 air x 50.7 M3 >> 300 mg HCN/kg air IDLH = 50 ppm ~ 47 mg/m3 TLV = 5 mg/m3 (1.9 kg/M3 air x 38 M3)/ 1 kg/1000 g • See notes for conversions • ** Actual yield likely to be only 20% 18 g HCN/m3 air “only” 18000 mg/m3

• CORRECTED SLIDE

Presenter

Presentation Notes

2.2 kg/1 lb. x 1000 g/kg x 32 oz./lb. = 28.4 g/oz. Check re density of air 1M3/1000 Liters /24.45 liters/mole @STPD x *[28 g MoleN2 x0.79 + 32 g O2 mole x 0.21] ~ 1.9 g/M3 air (0.0019 g/cc)

100

Spills and Worst Case Calculations [How bad could it be?]

• Maximum concentration in a given (confined) area

• Limitations (and K factors)

• Saturation calculations

• Steady-state situations

101

Decay Curves [How soon will it get better?]

• Ct= C0e-λt

• Ct concentration at a given time, t • C0 = initial concentration • Λ = rate of change per unit time (example air changes per hour)

• t = time e = natural log 2.71

• Rate of change x log e = log C0 – log C

Presenter

Presentation Notes

e (mathematical constant) From Wikipedia, the free encyclopedia http://en.wikipedia.org/wiki/E_(mathematical_constant) Jump to: navigation, search e is the unique number such that the value of the derivative of f (x) = ex (blue curve) at the point x = 0 is exactly 1. For comparison, functions 2x (dotted curve) and 4x (dashed curve) are shown; they are not tangent to the line of slope 1 (red). The mathematical constant e is the unique real number such that the value of the derivative (slope of the tangent line) of f(x) = ex at the point x = 0 is exactly 1. The function ex so defined is called the exponential function, and its inverse is the natural logarithm, or logarithm to base e. The number e is one of the most important in mathematics,[1] alongside the additive and multiplicative identities 0 and 1, the imaginary unit i, and π, the circumference to diameter ratio for any circle in a plane. It has a number of equivalent definitions; some of them are given below. The number e is occasionally called Euler's number after the Swiss mathematician Leonhard Euler, or Napier's constant in honor of the Scottish mathematician John Napier who introduced logarithms. (e is not to be confused with γ – the Euler–Mascheroni constant, sometimes called simply Euler's constant.) Since e is transcendental, and therefore irrational, its value cannot be given exactly as a finite or eventually repeating decimal. The numerical value of e truncated to 20 decimal places is: 2.71828 18284 59045 23536...

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Decay Curves [How soon will it get better?]

• From a prior problem • Concentration of acetone = 0.0078 x10-6 = 7831 ppm

• Ct= C0e-λt

• If the ventilation provides 5 air changes per hour, what will the concentration be after one hour?

• Ct = 7831 ppm x (2.71)-5 = 7831 ppm x 0.0069 • Ct = 53.6 ppm << TLV 750 ppm • Response to this emergency may be to cut off

electrical systems (spark producers) and keep the ventilation operating for a couple of hours

Presenter

Presentation Notes

One liter of acetone* spills within a room 6 m x 8 m x 3 m (Approximately 20 x 25 x 10 foot ceiling) Assuming rapid and complete evaporation, what will the maximum airborne concentration be? Volatile solvent used in nail polish remover and many ordnance operations V(solvent vapor) = 439 liters = 0.00305v/V = 0.3% V (room)* = 144000 liters = 0.00305 = 0.3% = 3049 parts per million (ppm) ** >> 750 ppm (Threshold Limit Value) *V (Volume of room) = 144 m3x 1000l/m3 0.00305 x 106 = 3049 ppm>>750 (occupational exposure limit) ** x [ 106 for ppm conversion] The bad news – solvent concentration is much greater than occupational exposure standard. The good news – solvent concentration below lower explosive limit 1%

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Concentration Decay Curves [How soon will it get better?]

Air changes

Ct Ct % change

0 1 1.00000 0

0.5 0.607456739 0.60746 -39

1 0.36900369 0.36900 -63

2 0.136163723 0.13616 -86

3 0.050244916 0.05024 -94.98

5 0.006841535 0.00684 -99.32

10 4.68066E-05 0.00005 -100.00

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• Should be part of systems engineering process – Suggest making this a contract deliverable – Consider compatible data formats and link to user

training • Emergency Response

– Planning should identify realistic scenarios • What could plausibly go wrong?



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Estimating chemical concentration and exposures

• Background information – Basics to begin (before you reach for the calculator) – Conversions, spills and other yucky stuff – Ideal gas law (college chemistry)

• Tools for estimating airborne chemical concentration and their dispersion. – Preliminary worst case estimates – Dispersion in closed room – Concentration in steady-state situations – Limited information on dispersion modeling for

outside exposures

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Basics –before you start from the beginning and/or reach for the checkbook

• Process review and hazardous material identification from standard practice guides

• Surveys of similar processes/operations/ work environments – NIOSH Health Hazard Evaluations – Industrial hygiene evaluation from service public health centers

(Example Navy BUMEDINST 6270.8A, Obtaining Health Hazard Assessments).

– Related industrial setting/ contractors

• Obvious control measures (containment, process selection and management) – Protective equipment and skin protection – Early warnings and general indicators – Especially from similar operations

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More Basics –before you reach for the calculator

• Process review and hazardous material identification

• Obvious control measures (containment, process selection and management)

• Protective equipment and skin protection • Early warnings and general indicators

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Considerations for Solvent Spills Ideally, in the planning phase

• Initial concerns for fire and explosion – Flammability

• lower and upper explosive limits • Flash point

– Consider vapor pressure

• Projection of inhalation exposures – Quantity of material used – Characteristics; Toxicity, volatility, warning properties – Ideal gas law to estimate exposures

• Emergency Response (and its limitations)

Content of Material Safety Data Sheets

(MSDS) and

Safety Data Sheets (SDS)

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The revised Hazard Communication Standard (HazCom 2012) requires that the information on the SDS be presented using specific headings in a specified sequence.

Safety Data Sheets Similar to Material Safety Data Sheets

Provide a good outline of necessary chemical and physical safety information

The SDS format is the same as the ANSI standard format which is widely used in the U.S. and is already familiar to many employees.

Slide courtesy of OSHA Training Institute

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The format of the 16-section SDS should include the following sections: Section 1. Identification Section 2. Hazard(s) identification Section 3. Composition/information on ingredients Section 4. First-Aid measures Section 5. Fire-fighting measures Section 6. Accidental release measures Section 7. Handling and storage Section 8. Exposure controls/personal protection Section 9. Physical and chemical properties

Slide adapted from the OSHA Training Institute

The format of the 16-section SDS should include: Section 10. Stability and reactivity Section 11. Toxicological information Section 12. Ecological information Section 13. Disposal considerations Section 14. Transport information Section 15. Regulatory information Section 16. Other information, including date of preparation or last revision

112 Slide adapted from the OSHA Training Institute

Presenter

Presentation Notes

The SDS must also contain Sections 12-15, to be consistent with the United Nations' Globally Harmonized System of Classification and Labeling of Chemicals (GHS). Although the headings for Sections 12-15 are mandatory, OSHA will not enforce the content of these four sections because these sections are within other agencies' jurisdictions.

Safety Data Sheet

SDSs are prime sources of information on health hazards.

Slide adapted from the OSHA Training Institute

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http://www.google.com/url?sa=i&source=images&cd=&cad=rja&docid=EaNL3TKNMLtZSM&tbnid=T9LVU0u4dD6kBM:&ved=0CAgQjRwwAA&url=http://www.mirsinfo.com/msdsms.htm&ei=komzUaDQLu32igKvmIGACw&psig=AFQjCNF3_jLIT8mw-P9xX4FIrLGQgkJGIw&ust=1370807058796589

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• Should be part of systems engineering process – Suggest making this a contract deliverable – Consider compatible data formats and link to user training

• Emergency Response – Planning should identify realistic scenarios

• What could plausibly go wrong?



HAZMAT evaluation- Identify the HAZMATs’

• Quantity, characteristics, and concentrations of the materials

• Source documents, such as Material Safety Data Sheets (MSDSs), vendor’s information

• Material hazards, including hazardous waste, and determine associated risks. (See MSDS/SDS) – Acute health, chronic health, carcinogenic, contact,

flammability, reactivity, and environmental hazards. • How the HAZMAT is used for each process or component

– Estimate the usage rate of each HAZMAT for each process or component

• Recommend the disposition for each HAZMAT • Potential substitutions

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Presenter

Presentation Notes

More on what’s in a hazmat evaluation (Mil Std 882- Task 207, para 207.2.3.1. Source documents, such as Material Safety Data Sheets (MSDSs), and information from vendors and sub-vendors for components of systems and subsystems Material identification includes material identity, common or trade names, chemical name, CAS number, national stock number (NSN), local stock number, physical state, and manufacturer and supplier names and contact information (including information from the Department of Defense HAZMAT information resource system). b.

Health Hazard Assessment in System Safety …Health Hazard Assessment in System Safety Evaluation...

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