Isocyanate paint use studies - typical exposure figures

Isocyanates are a very common cause of occupational asthma and, to help persons
who must assess risks in the workplace and devise controls, a British Health
and Safety Laboratory study report has arrived at typical exposure figures for
airborne isocyanate SMART (Small to Medium Area Repair Technique) spraying

SMART repairs techniques are carried out as an alternative to larger scale and
more complex body shop repairs, often for improving cosmetic appearance prior
to sale of a vehicle. Typical areas for SMART repair include scuffed bumpers,
stone chips, dents, scratches and damaged alloy wheels. It is not possible
accurately to define a SMART repair, however, the repair would not require
replacement or respray of a whole panel or bumper, is unlikely to exceed an
area of 1000 cm2 and typically would be carried out on site rather than in a
spray booth or spray room.SMART repair techniques are becoming increasingly
popular and HSE is developing guidance for users.

3 different SMART vehicle repair operators were studied in different modes of
use - a mobile repairer with no enclosure, a  workshop-based repairer and a
mobile repairer with portable enclosure.

Over short periods of paint application, airborne isocyanate concentrations in
excess of 70µg/m were measured, the academics make recommendations and confirm
that air-fed respiratory protective equipment is essential when SMART spraying
using isocyanate paints.

Further info

AplusA-online.de - Source: Health and Safety Executive