Hazardous Chemical Information System (HCIS)

Coal dust

Exposure Standard first adopted in 1990

Documentation notice: National Occupational Health and Safety Commission documentation available for these values.

No standard should be applied without reference to Guidance on the interpretation of Workplace exposure standards for airborne contaminants.

1. BACKGROUND INFORMATION

The coal mining industry in Australia has occupational health and safety mechanisms to closely monitor coal dust exposure and health effects . The industry currently works to an exposure standard of 3mg/m³ for respirable coal dust . This exposure standard has bean developed to address the problem of pneumoconiosis . Based upon the pneumoconiosis research findings of British National Coal Board⁽¹⁾, this exposure standard is most applicable to underground mining, but should also apply to the use of coal in other industrial situations . Methods of measurement ⁽²⁾ for respirable coal dust exposure is based on the British methods^(3,4,5) which conform to the recommendations of the British Medical Research Council ("Johannesburg Curve").

Surveillance studies on the prevalence of pneumoconiosis in the New South Wales ⁽⁶⁾ and Western Australia ⁽⁷⁾ have revealed that clinically significant pneumoconiosis is being eliminated . However, it is still uncertain whether other health effects, such as chronic bronchitis and obstructive lung disease, will also be well controlled ^(7,8).

The American Conference of Governmental Industrial Hygienist (USA) threshold limit value⁽⁹⁾ of 2mg/m³ for respirable coal dust is also based on the British National Coal Board's research findings . However, in the USA , different sampling strategies and different respirable dust sampling criteria are used, which can sometimes give rise to higher gravimetric measurements for coal dust when compared to the methods used in Australia .

2. RECOMMENDATION FOR EXPOSURE STANDARDS

The Exposure Standards Working Group recommends that a time-weighted average exposure standard of 3mg/m³ (respirable) be adopted for coal dust which contains less than 5% quartz . This exposure standard is based on its historical use in Australia ; and should also be low enough to control pneumoconiosis in coal mines.

Presently, the Working Group is keeping the exposure standard for coal dust under review and will be further evaluating the lung parenchymal and airway health effects associated with this exposure level.

REFERENCES

1. Jacobsen M et al, "New dust standards for British coal mines", Nature, 227, 445-447, 1970

2. Standards Australia , AS 2985-1987, Workplace Atmospheres: Method for Sampling and Gravimetric Determination of Respirable Dust, SAA, Sydney , 1987

3. The Coal Mines Regulation Act 1982 (NSW) and regulations

4. The Coal Mining Act 1925 (QLD) and regulations

5. Coal Mines Regulation Act 1946 ( WA ) and regulations

6. Griffiths R, "A historical review of airborne coal dust levels and the prevalence of occupational lung disease in New South Wales coal mines 1948-1988", Presented at the VIIth International Pneumoconiosis Conference, Pittsburgh, USA, 1988

7. Holman CDJ et al (ed), The Respiratory Health of Employees of the Collie Coal Mining Industry, Health Department of Western Australia, Occasional Paper/22, Perth, 1988

8. Leigh J et al, "Total population study of factors affecting chronic bronchitis prevalence in the coal mining industry of New South Wales, Australia", Brit Ind Medicine, 43, 263-271, 1986

9. American Conference of Governmental Industrial Hygienists, Documentation of the Threshold Limit Values and Biological Exposure Indices, 5th edition, Ohio , 1986

Footnotes:

Documentation notice:

Entries carrying a notice for National Occupational Health and Safety Commission documentation indicate that these substances have been reviewed in detail by the Exposure Standards Expert Working Group and that documentation supporting the adopted national values is available in the National Commission's Documentation of the Exposure Standards [NOHSC:10003(1997)].