[Diseases caused by diisocyanates. 2. Diisocyanate asthma].

Diisocyanates are widely used as polymerizing agents in the production of polyurethanes. Exposure to high concentrations of toluene diisocyanate (TDI) causes the development of toxic-irritative symptoms in the respiratory tract. It has been observed that some workers, after repeated exposures and a latent period of months to years, develop asthmatic symptoms upon re-exposure to minute concentrations of diisocyanates. An immunological mechanism for this typical extrinsic asthma has not been adequately documented.