In the motor vehicle repair industry (MVR) after a car or car-part has been sprayed it is often placed in a booth at elevated temperature to speed curing of the isocyanate. This is known as baking or the bake-cycle. During the bake-cycle the air to the booth is usually re-circulated which could increase airborne isocyanate concentrations inside the booth and associated ductwork. This could lead to NCO exposure if an unprotected worker entered the booth during the bake-cycle or if the booth leaked or was not cleared of residual vapour at the end of the cycle.
Similarly sanding (flatting) of car-parts painted with NCO containing materials could also be a source of exposure. Sanding is most usually done on primer paints but sometimes a finished car-part may need to be sanded back to the bare metal (i.e. topcoat, colour-cot and primer layers removed) if the spray job has not been successful.
This report evaluates the risks from these processes.