Toluene diisocyanate respiratory reactions. I. Reassessment of the problem.

A series of workers with exposure to and respiratory symptoms from toluene diisocyanate (TDI) was compared with a group of exposed, asymptomatic workers and with normal controls using immunologic and clinical evaluations. Improved understanding of TDI-induced respiratory disease may best be achieved by categorizing the symptomatic workers into at least 3 and possibly 4 groups: immunologic TDI asthma; pre-existing chronic respiratory disease exacerbated or unaffected by TDI; asthma coincidental with TDI exposure, and possibly TDI respiratory disease secondary to toxic or inflammatory mechanisms.