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Occupational Hygiene: Evaluation of

Chemical Health Risks – Part 2Frances Wright

Occupational Hygiene: Evaluation of Chemical Health Risks – Part 2

Frances Wright

Occupational HygienistWright Environmental Services

Module OSH10020

Part 1

Chemical – Risk Assessment

Part 2

Physical Forms and Processes

Occupational Hygiene: Evaluation of Chemical Health Risks

Inhalation

Dust/Particles

Physical Forms

Gases Vapours

Dust/Particles Dust/Particles� Total Inhalable Dust

– size range up to 100mm

� Respirable Dust

– size range up to10mm

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Occupational Hygiene: Evaluation of

Chemical Health Risks – Part 2Frances Wright

Dust/Particles� Fibre – solid particulate which are long and

thin

– Eg. asbestos, MMMF

� Fume - solid particles produced by

condensation

– eg. Welding fume, soldering fume

� Mist - liquid particles

– Chromic acid mists (electroplating)

Dust/Particles - Process

Bagging of powders

Dust/Particles - Process

Woodwork

Wood dust

OELV : 5 mg/m3

Dust/Particles - Process

Flour dust

OELV : 1 mg/m3

Bakery

Dust/Particles - Process

Quarrying

Crystalline Silica

OELV : 0.1 mg/m3

Dust/Particles - Process

Welding

Welding Fume

OELV : 5 mg/m3

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Occupational Hygiene: Evaluation of

Chemical Health Risks – Part 2Frances Wright

Dust/Particles - Process

Removal/Maintenance on Asbestos

Asbestos

OELV: 0.1 fibres/cm of air

Gases

Gas - Process

Nitrous Oxide

OELV 90 mg/m3

Hospital – Aesthetic Gas

Gas - Process

Hydrogen Sulphide

OELV : 7mg/m3

STEL : 14mg/m3

Farming – Slurry Pits

Gas - Process

Burning Fossil Fuels

Carbon monoxide

OELV : 23 mg/m3

STEL: 115mg/m3

Gas - Process

Printers

Ozone

OELV : 0.05 – 0.2 ppm

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Occupational Hygiene: Evaluation of

Chemical Health Risks – Part 2Frances Wright

Vapours Vapour - Process

Paint Spraying

Isocyanates

OELV : 0.02 mg/m3

STEL : 0.07 mg/m3

Vapour - Process

Dry Cleaning

TetrachloroethyleneOELV : 170 mg/m3STEL : 678 mg/m3

Vapour - ProcessChemical Industry – Various Solvents

e.g. Toluene

OELV : 192 mg/m3

STEL : 384 mg/m3

e.g. Xylene

OELV : 221 mg/m3

STEL : 442 mg/m3

Dust/Particles

Summary

Gases Vapours Part 1

Chemical – Risk Assessment

Part 2

Physical Forms and Processes

Occupational Hygiene: Evaluation of Chemical Health Risks

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Occupational Hygiene: Evaluation of

Chemical Health Risks – Part 2Frances Wright

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.