Occupational asthma due to isocyanates in Singapore.

Nine cases of occupational asthma due to isocyanates are described. The isocyanates involved included toluene diisocyanate (TDI), diphenyl-methane diisocyanate (MDI) and polyisocyanates. The importance of asking the occupational history in a patient with asthma is illustrated. The importance of early diagnosis and removal from further exposure is also discussed.