Cutaneous sensitization to some polyisocyanate prepolymers in guinea pigs

Isocyanates are used extensively in the polyurethane industry. Pulmonary an d dermal sensitization resulting from exposure to diisocyanates has frequen tly been reported, but the potential effects of polyisocyanates on health a re less well known. Thus, since 1978, occupational exposure limits have bee n established for diisocyanates only. Nevertheless, respiratory diseases an d dermatitis have been reported in the polyurethane industry after accident al isocyanate contact during spills or splashes. The aim of this experiment al work was to assess the dermal hypersensitivity of guinea pigs to some po lyisocyanate prepolymers by means of a well-conducted standard predictive B uehler test. Our results showed that dicyclohexylmethane 4,4'-diisocyanate (HMDI), toluylene 2,4-diisocyanate (TDI), TDI adduct triol, TDI isocyanurat e, 1,6-hexamethylene diisooyanate (HDI), HDI isocyanurate, HDI biuret and i sophorone diisocyanate (IPDI) induced dermal sensitization while IPDI isocy anurate did not. In conclusion, the dermal hypersensitivity of guinea pigs to some polyisocyanates was similar to those of their corresponding monomer s except for IPDI isocyanurate, suggesting that the results from diisocyana te monomers could not be a valuable approach for the detection of the sensi tization potency of the corresponding prepolymers.