Absence of respiratory effects in subjects exposed to low concentrations of TDI and MDI: a reevaluation.

Because of criticisms of the authors' previously reported study showing absence of respiratory effects in subjects exposed to low concentrations of toluene diisocyanate (TDI) and diphenylmethane diisocyanate (MDI), the data have been reanalyzed. This reanalysis confirms the accuracy of the results and the conclusions based on them. Subjects exposed to 0.0010 to 0.0015 ppm of TDI and around 0.0003 to 0.0006 ppm of MDI demonstrated a normal age- and smoking-related rate of decline in forced expiratory volume in 1 s and no evidence that it was related to isocyanate exposures. Control of isocyanate exposure sufficient to protect industrial workers against measurable deterioration in lung function appears feasible.