RR1199: Ensuring improved isocyanate exposure assessment to better protect health
Isocyanate exposure is one of the leading causes of occupational asthma in Great Britain (GB). Exposure can also cause dermatitis and irritation of the eyes, nose and throat. Isocyanates are widely used in industry, particularly in spray painting, adhesives, flexible foam and polyurethane resin production. Dutyholders must ensure that effective control measures are in place to protect workers. Dutyholders may use air monitoring to demonstrate that airborne isocyanate levels are below the workplace exposure limit (WEL). Dutyholders may use biomonitoring of workers to ensure that exposure control measures are effective. These established HSE monitoring methods have some drawbacks for users, for example, a license is needed to use the air monitoring method, MDHS 25/4, because it uses a restricted chemical. Also, the HSE urine biomonitoring method does not distinguish between exposure to isocyanates and some other chemicals.
This report describes research to evaluate the suitability of potential alternative monitoring methods. It will be of interest to technical specialists undertaking isocyanate sampling and/or analysis. The research included a literature review, laboratory studies, and tests at three volunteer sites (3D printing, a foundry, and aerospace). The researchers’ conclusions are: (1) MDHS 25/4 continues to be the most suitable approach to demonstrate compliance with the WEL. (2) HSE’s methods for air monitoring and biomonitoring continue to be the most suitable for use in GB and may be adaptable as alternative isocyanates come to market. (3) Other monitoring methods may be appropriate in certain circumstances but are unlikely to be universally applicable for the measurement and analysis of all isocyanates.
This report and the work it describes were funded by the Health and Safety Executive. Its contents, including any opinions and/or conclusions expressed, are those of the authors alone and do not necessarily reflect HSE policy.
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