Why test for isocyanate exposure?
Isocyanates are one of the leading
causes of occupational asthma in the UK. As respiratory
sensitisers, exposures to isocyanates should be kept as low as
reasonably practicable and this often requires the use of
respiratory protective equipment (RPE). Biological
monitoring is a simple and cost-effective way of checking that
control measures are working and being used correctly. Our case
studies show the utility of using biological monitoring for
assessing isocyantate exposures in
paint spraying and floor
Isocyanates are widely used in
industry but have particular application in spray painting, foam
and polyurethane manufacture and in adhesives. HSE recommends that vehicle spray painters
undertake biological monitoring annually to check that exposure is
being adequately controlled. Biological monitoring can be carried
out by anyone who understands the principles (see HSE's guidance) but you may find it convenient
to arrange annual isocyanate testing as part of your health
surveillance (health surveillance is required for workers using
How to sample?
UKAS-accredited biological monitoring analysis for HDI and IPDI
(found in spray paints), TDI (foams and glues) and
MDI (resins and hardeners). A urine sample is required and should
be taken at the end (within an hour) of a period of potential
exposure. Sampling should reflect normal working practice. Urine
samples should be collected in bottles containing a citric acid
preservative. HSL provides bottles and packaging as part of the
What to test for?
In order to improve the quality of
our data collection, we would like to encourage clients to only
request the analysis of the isocyanates actually used by the
workers being tested - most only use one or two isocyanates.
request form has been developed for isocyanates to help you
identify which isocyanates are in use. We are also willing to
look at your safety data sheets if you are unsure which isocyanates
you should be monitoring.
What do the results mean?
We have produced guidance on
biological monitoring for isocyanates for both employers and employees. HSL
scientists will help interpret results from samples that we
have analysed where required. There is also a UK guidance
to aid interpretation.
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