Occupational exposure limits--Britain tries again.

Since the Control of Substances Hazardous to Health (COSHH) Regulations came into force about 12 yr ago, Britain has had a legally enforceable system of exposure limits. This is now likely to have a major overhaul. There are at present two types of limit, Occupational Exposure Standards (OESs), which broadly speaking are supposed to be set low enough to prevent any ill-health developing, and Maximum Exposure Limits (MELs), which are set for substances that have ‘serious health implications’ and for which it is not always practicable to achieve a level that will prevent disease. OESs can be exceeded under some circumstances, and exposure by inhalation does not have to be reduced any further than the OES. MELs define a maximum permissible exposure, but exposure must also be reduced as far as reasonably practicable. (This is a legally defined concept which means that exposures must be reduced to a level where further reduction would involve a cost grossly disproportionate to the benefit achieved.) Topping (2001) recently described the system in detail. The list of limits, and guidance aimed at employers, is published annually in EH40 (Health and Safety Executive, 2002). This system has strengths, notably the frank recognition that for some substances a desirable limit to protect health is not practicable, and the involvement of experts nominated by employers’ and employees’ organizations and other interests in determining for which substances a MEL is applicable, and what the level should be. However, a market survey on behalf of the Health and Safety Executive (HSE) showed that the carefully negotiated and executed dual-limit system was an almost complete failure in terms of the all-important understanding and application by users of chemicals (Topping et al., 1998). There were other problems intrinsic to the system which have become more troublesome as time has gone by, and the need to run a system compatible with the European Union’s Chemical Agents Directive has increased the problems. The HSE has now issued a discussion document on a possible new scheme with a view eventually to changing the COSHH Regulations. The document can be downloaded from http://www.hse.gov.uk/condocs, and comments are invited by the end of July; but there will be a further consultation later on the more formal legislative proposals.