Isocyanates are commonly used in industries including Motor Vehicle Repair (MVR)- paint spraying, foam & polyurethane manufacture, in adhesives, glues and MDI resins and hardeners.
Isocyanates are known respiratory sensitizers and an important cause of occupational asthma in the UK. Exposure to isocyanates should be kept as low as reasonably practicable and respiratory protective equipment should be used.
Biological monitoring is one method checking that control measures are working and being used correctly.
HSE recommend that vehicle spray painters undertake biological monitoring annually to check that exposure is being adequately controlled. Annual isocyanate testing can be performed as part of the health surveillance, which is required for workers using isocyanates.
A urine sample is required and, ideally, should be obtained at the end of the working day. The results are provided by the Health & Safety Laboratory in accordance with UK Biological Monitoring guidance values (BMGV). Biological monitoring analysis for HDI and IPDI (found in spray paints), TDI (foams and glues) and MDI (resins and hardeners) can be undertaken. A urine sample is required and should be taken at the end (within an hour) of a period of potential exposure.
Employees working with isocyanates also require health surveillance for asthma, because isocyanates can cause occupational asthma. Health surveillance for asthma includes a regular (at least annual) questionnaire and lung function test carried out by an occupational health doctor or nurse.