An Assessment of the Robustness of the COSHH-Essentials (C-E) Target Airborne Concentration Ranges 15 Years on, and Their Usefulness for Determining Control Measures

Abstract

The Health and Safety Executive (HSE) in Great Britain (GB), in association with its stakeholders, developed the Control of Substances Hazardous to Health (COSHH)-Essentials (C-E) control banding tool in 1998. The objective was to provide a simple tool for employers, particularly small and medium-sized enterprises (SMEs), to help select and apply appropriate measures for the adequate control of exposure to hazardous substances. The tool used hazard classification information (R-phrases) to assign substances to one of five health hazard groups, each with its respective 'target airborne concentration range'. The validity of the allocation of substances to a target airborne concentration range was demonstrated at the time using 111 substances that had a current health-based Occupational Exposure Limit (OEL) in GB. The C-E control banding approach remains an important tool to complement exposure assessment/monitoring and the selection and use of suitable control measures for hazardous substances. These include engineering controls and personal protective equipment (PPE). The C-E based control banding approach has been adopted around the world. This paper extends the original validation exercise, using a greater number of chemical substances, to establish whether the target airborne concentration ranges remain appropriate. This is of particular interest in light of the introduction of the Globally Harmonized System (GHS) for classification, in which R-phrases have now been replaced by hazard-statements (H-statements). The validation exercise includes substances with OELs published by nine bodies internationally; and the Derived No-Effect Levels (DNELs) assigned by registrants under the European Union-Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) Regulations. When compared against 8-hour TWA OELs for 850 substances drawn from nine bodies and a limited number of DNELS, the C-E target airborne concentration ranges remain valid. This comparative work also informs a wider consideration around the practicality and the applicability of the C-E generic approach to facilitate the implementation of good practice control for a wide range of substances (more than 95%) which do not have any recognized OEL.

Industry Derived Occupational Exposure Limits: A Survey of Professionals on the Dutch System of Exposure Guidelines

“…A precautionary approach seems reasonable, however, many of the respondents seem to find current available approaches based on hazard banding to be unreasonably conservative. Vaughan and Rajan-Sithamparanadarajah (2017) showed that the exposure concentration ranges of COSHH Essentials corresponded to the 10th percentile of OELs for substances in that hazard band. Assuming the subset of substances with OELs is representative for the subset without OELs, this implies a relatively high degree of protection.…”

<p>Experimental Application of Semi-Quantitative Methods for the Assessment of Occupational Exposure to Hazardous Chemicals in Research Laboratories</p>

“…3,4 Moreover, owing to the high number of chemicals currently on the market, the OELs are available only for a small percentage of the hazardous substances, lower than 5%. 5 For the chemicals without a OEL is not possible to assess a chemical work-related risk by a quantitative measurement. In these cases, a simplified semi-quantitative tool may help during chemical risk assessment activities.…”