Isocyanates are used extensively in the polyurethane industry. Pulmonary and dermal sensitization resulting from exposure to diisocyanates has frequently been reported, but the potential effects of polyisocyanates on health are less well known. Thus, since 1978, occupational exposure limits have been established for diisocyanates only. Nevertheless, respiratory diseases and dermatitis have been reported in the polyurethane industry after accidental isocyanate contact during spills or splashes. The aim of this experimental work was to assess the dermal hypersensitivity of guinea pigs to some polyisocyanate prepolymers by means of a well-conducted standard predictive Buehler test. Our results showed that dicyclohexylmethane 4,4'-diisocyanate (HMDI), toluylene 2,4-diisocyanate (TDI), TDI adduct triol, TDI isocyanurate, 1,6-hexamethylene diisocyanate (HDI), HDI isocyanurate, HDI biuret and isophorone diisocyanate (IPDI) induced dermal sensitization while IPDI isocyanurate did not. In conclusion, the dermal hypersensitivity of guinea pigs to some polyisocyanates was similar to those of their corresponding monomers except for IPDI isocyanurate, suggesting that the results from diisocyanate monomers could not be a valuable approach for the detection of the sensitization potency of the corresponding prepolymers.

The diallylglycol carbonate monomer causes dermatitis due to irritation in the optical industry. Cutaneous intolerance may effect as many as 70% of the exposed persons employed. Almost all control subjects who where patch-tested showed irritation at a 2% concentration. The histological effects were an acute oedema with inflammation of the papillary dermis, and diapedesis of neutrophil polymorphonuclear leukocytes. Experiments on animals confirmed the irritant nature of the product; in the rabbit, a single application produced irritation, but to a lesser degree than in humans. Tests for possible sensitizing effects in the guinea pig have given negative results. Chemical analysis of the monomer revealed the presence of diallyl carbonate and acrolein. Allyl alcohol was detected in only one case. Patch tests were carried out in a group of control subjects with acrolein, diallyl carbonate and allyl alcohol. The histological appearance of the lesions caused by acrolein was quite different from that due to diallyglycol carbonate. It is probable that the irritant is the diallylglycol carbonate monomer itself.