To: Directors of Environmental Health/ Chief Environmental Health Officers of London, Metropolitan, District and Unitary Authorities and Chief Executives of County Councils.

For the attention of: Environmental Services / Trading Standards / Fire Authorities / Other

This circular gives advice to local authority enforcement officers

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OCCUPATIONAL EXPOSURE LIMITS AND MONITORING STRATEGIES- GUIDANCE NOTES EH40/2000 AND HSG173

INTRODUCTION

1 This circular contains information on Guidance Note (GN) EH40/2000 and HSG173. GN EH40/2000 gives details of the occupational exposure limits (OELs) which should be used when considering the adequacy of control of exposure to substances hazardous to health under the Control of Substances Hazardous to Health Regulations 1999 (COSHH); GN HSG173 gives advice on monitoring strategies for toxic substances in the light of COSHH.

2 Both EH40/2000 and HSG173 should be read in conjunction with the COSHH Regulations and the COSHH General Approved Code of Practice. Although much of the emphasis is on exposure by inhalation, it is important to remember that COSHH covers all exposure routes and that achievement of adequate control for inhalation does not necessarily mean that control is adequate overall.

GN EH40/2000

1 3 Simple asphyxiants eg argon do not come under COSHH (see Supplementary Information for Tables 1-3, Pages 41-42 of GN EH40/2000) the problem being solely one of oxygen deficiency. However, when an asphyxiant also has toxicological properties COSHH will apply, eg carbon dioxide.

4 The OELs listed in GN EH40/2000 apply at normal temperatures and pressures and are not necessarily valid at extremes of temperature and pressure, eg in hyperbaric and diving chambers and in compressed air working. In any similar situations advice should be sought from HSE via the local enforcement liaison officer (ELO).

GN HSG173

5 HSG173 advises that because of variations in plant, process, work and other conditions it is difficult to draw conclusions about long-term exposure patterns on the basis of a single measurement of exposure at one point in time. It also advises that when interpreting results and reaching conclusions it needs to be remembered that the COSHH Regulations require that protection be given to all employees; conclusions need to show that the results are equally applicable to others similarly exposed.

FURTHER ADVICE

6 Guidance note EH40/00 'Occupational Exposure Limits' ISBN 0 7176 1730 0, £9.50 and HSG 173 'Monitoring strategies for toxic substances' ISBN 0 7176 1411 5, £6.95, are both available from HSE Books, PO Box 1999, Sudbury, Suffolk CO10 2WA, telephone 01787 881165.

7 Further advice can be obtained via the ELO.

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