The objective of this report is to evaluate the likely exposure caused by mixing and brush and roller application of isocyanate paints. Isocyanates are highly reactive chemicals used in the motor vehicle repair, adhesives, polyurethane and coating industries. They are known respiratory tract and skin sensitizers and are the most common cause of occupational asthma in the UK. The Health and Safety Executive has set maximum exposure limits. Isocyanates paints can be applied by spraying or by brush or roller.