[The irritant and allergenic action of two isocyanates: toluene diisocyanate (TDI) and diphenylmethane diisocyanate (MDI)].

This is a study on the irritant capacity of two isocyanates (T. D. I. Toluene diisocyanate and M. D. I. diphenyl methane diisocyanate). The experiment was carried out on the hide and ocular mucous membrane of albino rabbits, using Draize method as well as the method for appraising cosmetics. An histopathological examination of the evolution of the lesions was then achieved together with a study on the delayed allergenic capacity. This study was carried out on albino guinea-pig hides using Kligman and Magnusson technique. In these experimental conditions, the conclusions were the following:--on rabbit hide, T. D. I. is a medium irritant, more caustic than M. D. I.,--on ocular mucous membrane, M. D. I. is a mild irritant; T. D. I. a strong one,--on guinea-pig hide, T. D. I. and M. D. I. may induce cutaneous sensitivity similar to contact allergy. Their allergenic capacity is long lasting but varies according to the allergen concentration.