Peter Simmonds 021-02912826 prsimmonds@clear.net.nz My Background - - PowerPoint PPT Presentation

Occupational Hygiene Peter Simmonds 021-02912826 prsimmonds@clear.net.nz

My Background

• Scientist with the Ministry of Health at the

National Health Institute (Porirua).

• Worked in consultancies in the UK,

Australia and New Zealand.

• Certified Occupational Hygienist through

the Australian Institute of Occupational Hygienists and the International Occupational Hygiene Association.

Outline

• 1. What is Occupational Hygiene
• 2. Recent history of the profession
• 3. Structured Exposure Risk assessments

– the good and not so good

• 4. Health and Safety by Design

What is Occupational Hygiene

The International Occupational Hygiene Association (IOHA) defines Occupational Hygiene as: 'The discipline of anticipating, recognizing, evaluating and controlling health hazards in the working environment with the objective of protecting worker health and well-being and safeguarding the community at large.'

What is Occupational Hygiene

Where does that name come from! “the science that deals with the preservation

• f health”.

Hygeia was the Greek goddess of health

What is Occupational Hygiene

Aim to eliminate or control occupational health risks. We work at the top rather than the bottom of the cliff.

Recent history

1858 - John Stenhouse introduces a charcoal impregnated mask to control exposure to gases and vapours.

Recent History

1890s – Haldane works on the toxicity of carbon monoxide Exposes rats, mice and even himself to varying concentrations within an “exposure chamber”. He introduces the use of canaries to indicate the presence of toxic gas.

Recent History

First world war, the urgency of the work in munitions factories led to poor working conditions. Women filling shells with TNT were nick named the “Canary Girls”. The TNT turned their skin and pregnant women’s babies yellow. Anaemia and jaundice resulted in deaths.

Recent History

1917 - watch dials began being painted with radium paint. Women told to “point” brush with their lips to save time. Began to suffer from anemia, bone fractures and necrosis of the jaw, a condition now known as radium jaw. 1938 – A group of women successfully sued their employer and won damages

Recent History

1920s-30s Industrial hygiene develops and grows in the USA in both the Public and large private companies. 1938/9 The American Conference of Governmental Industrial Hygienists (ACGIH) and the American Industrial Hygiene Association (AIHA) were formed.

The ACGIH developed the Threshold limit values (TLV’s) - considered to be health based standards

Recent History

1953 British Occupational Hygiene Society (BOHS) was formed. 1979 The Australian Institute of Occupational Hygienists was formed and has around 1000 members. 1994 The New Zealand Occupational Hygiene Society was formed and currently has around 60 members.

Structured exposure risk assessments Risk assessment Mantra Anticipation Identification Assessment Controls

Structured Risk assessments

Case 1: Construction Steel fabrication industry Welding fume is the hazard being assessed

Structured Risk assessments

Risk Identification

• 1. Welding being undertaken - visual

presence of fume lingering in workplace.

• 2. Worksafe NZ (DoL) welding assessment

tool

• 3. Direct reading instruments
• 4. Safety data sheets (metal and welding

consumable composition)

Structured Exposure assessments Adverse health effects of welding fume

Mild steel welding – zinc, copper, iron (metal fume fever) manganese (neurologic effects)

Exposure standards

Welding fume (not otherwise classified) 5 mg/m3 Zinc Fume 3mg/m3 Manganese 1 mg/m3

Structured Risk Assessments

Similar Exposure Groups (SEG’s) Definition: A group of employees who have common risks and similar exposures. For a construction steel fabrication plant they maybe:

1.

Welders

2.

Welder/Fabricators

3.

Trade Assistants

4.

Supervisors/Design staff

Structured Risk Assessments

Measurements

Welding fume– Inhalable particulate sampling train.

Structured Risk Assessment

Adjustment for extended shifts

Workplace assessments based on eight hour personal measurements. For extended shifts – adjust the welding fume exposure standard

Structured Risk Assessments

Results analysis

SEG Number in group Welding fume exposures (mg/m3) Welders 2 16 Welders/fabricators 5 8 Trade assistant 4 4 Supervisory/design 3 3

Structured Risk Assessments

Statistical analysis

Hazard Number of measurements Average 95th Percentile % in excess of exposure standard Workplace Exposure Standard Welding fume 4 7.7 mg/m3 21 mg/m3 62 5

• Occupational exposures are generally log normally

distributed.

• Use mean for control purposes.

Structured Risk assessments

Controls

Hierarchy of Controls

• 1. Elimination
• 2. Substitution
• 3. Isolation
• 4. Engineering controls
• 5. Administrative controls
• 6. Personal protective equipment.

Structured Risk Assessments

Controls

• 1. Immediate controls would be a minimum of P2 respiratory

protection.

• 2. Training, fit testing of masks, lung function testing
• 3. Portable or fixed exhaust ventilation systems

Structured Risk Assessment

Ongoing issues with controls Compliance with the use of PPE Extraction systems not being used Extraction systems don’t reach the weld area.

Structured Risk Assessment

Case Study 1 – Summary

• 1. Presence of a hazard identified
• 2. Worker welding fume exposures assessed
• 3. Appropriate controls put in place

Not so structured risk assessment

Case Study 2 Nickel mine builds a plant to separate cobalt and nickel from the refined ore. Plant is a flotation system using a solvent in the process.

Not so structured risk assessment Site is concerned that benzene is present in the solvent. Undertakes biological monitoring for benzene metabolites in urine ( t,t muconic acid and S-phenyl mercapturic acid). Benzene metabolites identified in operators urine samples, some approach the Biological Exposure Index level (BEI)

Not so structured risk assessment Solvent used is Shellsol A150: Information from the safety data sheet:

• 1. Solvent naphtha (petroleum), heavy

aromatic

• 2. Hazardous Chemicals – Naphthalene and

tri methyl benzenes

• 3. Boiling point range: 180 – 214oC
• 4. Benzene boiling Point: 80oC (not on SDS)

Not so structured risk assessment Contract a Occupational Hygiene Consultancy to undertake an extensive solvent monitoring programme Interim monitoring report 44 personal and 77 area samples - small amounts of C9 – C12 hydrocarbons (tri methyl benzenes and naphthalene)

Not so structured risk assessment NO BENZENE DETECTED IN ANY OF THE AIR SAMPLES

Not so structured risk assessment

ANY IDEAS!

Not so structured risk assessment Benzene a component of cigarette smoke Highest biological monitoring results correlated with the heavy smokers

Not so structured risk assessment What went wrong?

Not so structured risk assessment

Control Biological monitoring is a control used to monitor the effectiveness of your controls – no baseline monitoring Assessment Rigorous assessment Identification Cigarette smoke contains benzene

As much as the process can be determined, the Company reversed the normal risk assessment procedures.

Health and Safety by Design

Recently involved in a Health and Safety by design project. New build powder coating plant

Health and Safety by Design

Involved professions:

1.

Production manager

2.

HSE Manager

3.

Safety Engineer

4.

Occupational Hygienist

5.

HSNO - Worksafe NZ

6.

Ergonomist

7.

Occupational Hygienist Worksafe NZ

Health and Safety by Design

Involved two one day meetings Initial “brain storming” meeting Second meeting - divided into groups and final all members meeting.

Health and Safety by Design

Some great ideas were generated during the meetings. The plant is still under construction. Proof will be in the pudding!

Any Questions?