Health and Safety Update (December 2008)
Isocyanate Exposure in vehicle repair premises
If your business is involved in spraying isocyanate based paints
then you should read on. A new HSE advisory leaflet has been
published that provides information on the role of biological
monitoring in controlling isocyanate exposure in the motor vehicle
repair (MVR) industry. The leaflet explains that:
- persons spraying isocyanates in MVR are exposed to a high
airborne concentration, much higher than the WEL;
- protection is only afforded by air-fed breathing
apparatus;
- work practices often involve removing the air-fed breathing
apparatus immediately after spraying to look at the quality of the
paint finish and / or to leave the booth;
- effective control relies on both physical provisions which can
fail or deteriorate and human behaviour which can be
inconsistent;
- many MVR paint sprayers have developed occupational asthma from
isocyanate exposure despite using air-fed breathing apparatus.
COSHH requires that biological monitoring should be undertaken
provided there is a suitable procedure and it is not obvious from
another evaluation method that exposure is adequately
controlled.
Biological monitoring looks at isocyanate metabolites in the
sprayer's urine and provides a practical method to check if
exposure is occurring. In 2007, more than 2,000 samples were
taken, and several insurance companies now require their MVR client
companies to undertake biological monitoring to prove that exposure
to isocyanates is being adequately controlled.
Care should be taken to ensure that sampling is representative.
Urine samples taken at the end of the shift only show exposure for
that shift nor can it indicate the route of exposure.
The leaflet provides details on who can carry out urine sampling
for isocyanate metabolites and also provides information on
enforcement action.