Occupational Hygiene: Evaluation of

Chemical Health Risks - Part 1

Frances Wright

1

Occupational Hygiene – Evaluation of Chemical Health Risks – Part 1

Frances Wright

Occupational HygienistWright Environmental Services

Module OSH10020 Learning OutcomesHaving completed all of the learning activities associated

with this lecture, you should be able to:

� Explain the categories of health hazards, and

describe the types of work activity associated with

common chemical hazards

� Describe the routes of entry for chemicals to the body

� Describe how hygienists monitor the work

environment for dusts, gases and vapours

� Define occupational exposure limits and discuss the

implications for human health.

Part 1

Chemical – Risk Assessment

Part 2

Physical Forms and Processes

Occupational Hygiene: Evaluation of Chemical Health Risks What is Occupational Hygiene?

The International Occupational Hygiene

Association (IOHA) defines Occupational

Hygiene as:

'The discipline of anticipating, recognising,

evaluating and controlling health hazards in

the working environment with the objective of

protecting worker health and well-being..'

What is Occupational Hygiene? Health Hazards

Chemical agents Gases, vapours, solids, fibres, liquids, dusts, mists, fumes, etc.

Physical agents

Noise and vibration

Heat and cold

Electromagnetic fields, lighting, etc.

Biological agents Bacteria, fungi, etc.

Ergonomic factors Lifting, stretching, and repetitive motion

Occupational Hygiene: Evaluation of

Chemical Health Risks - Part 1

Frances Wright

2

Chemical Agents Hazard Vs Risk� Hazard is the Chemical

� Risk is the potential to do harm

Identify Processes

& Workers

Evaluate the RiskControl the Risk

Document,

Communicate &

Review

Identify the Chemical Hazards

CHEMICAL

RISK ASSESSMENT

Identify the Chemical Hazard� Identify chemicals

– Talk to procurement, managers, employees

– Examine processes

– Chemicals Produced during process

• (e.g welding fume)

Identify the Chemical Hazard� Gather hazard information

– Material Safety Data Sheet

– Chemical label

Identify Processes and Workers

� Examine production process

� Who might be exposed

� Non-production handling

– (eg. waste, quality, maintenance, spillages)

Occupational Hygiene: Evaluation of

Chemical Health Risks - Part 1

Frances Wright

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Evaluate the Risk

� Toxicity of chemical

� Quantity used

� Frequency of exposure

� Number of people exposed

Evaluate the Risk� Measure worker exposure

� Breathing zone

� Methods – MDHS (UK), NIOSH, OSHA

Personal Sampling Pump Measurement tools

Measurement tools Filter holders for asbestos

Occupational Hygiene: Evaluation of

Chemical Health Risks - Part 1

Frances Wright

4

Solid Sorbent Tubes for

Measuring Gases and VapoursDraegar pump for stain indicator tubes

Direct Reading - Continuous Dust Monitor

Long Term Sampling

Short Term Sampling Grab Sampling

Occupational Hygiene: Evaluation of

Chemical Health Risks - Part 1

Frances Wright

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Continuous Monitoring Evaluate the Risk� Occupational Exposure Limit Values

– Occupational Exposure Limit Values (8 Hours)

– Short Term Exposure Limits (15 minute)

Evaluate the Risk

EXAMPLE: Total Inhalable Dust 8 Hour OELV = 10 mg/m3

CONCENTRATION = ANALYTICAL RESULT ÷ VOLUME

Analytical results (dust on filter) 0.05 mg

Air volume sampled 0.48 m3

Concentration in air 0.05/0.48 = 0.1mg/m3

Sampling time 4 Hours

Concentration over 8 Hours 0.1*(4/8) = 0.05 mg/m3

Compare the concentration (over 8 hours) to the 8 Hour OELV

0.05 mg/m3 is well below 10mg/m3

Hierarchy of Control

� Elimination

� Substitution

� Process Changes

� Engineering Controls

� Automation

� Containment

� Local Exhaust Ventilation

� General Area Ventilation

� Administrative Controls

� Respiratory Protective Equipment

Document, Communicate and ReviewSummary

Occupational Hygiene

Identify Processes

& Workers

Evaluate the RiskControl the Risk

Document,

Communicate &

Review

Identify the Chemical Hazards

CHEMICAL

RISK ASSESSMENT

Occupational Hygiene: Evaluation of

Chemical Health Risks - Part 1

Frances Wright

6

Part 1

Chemical – Risk Assessment

Part 2

Physical Forms and Processes

Occupational Hygiene: Evaluation of Chemical Health Risks