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.

We tried out the potential irritant and sensitizing effect of the main glycol ethers found in industrial and consumer products. Cutaneous irritation was determined in the rabbit following the EEC method (European Economic Communities) and the Draize protocol, and the sensitizing effect was evaluated in the guinea pig by the maximized Magnusson and Kligman method. The results showed no delayed cutaneous hypertensitivity, and all glycol ethers studied were classified from slightly irritant to severely irritant according to the Draize protocol, though only 2-butoxyethanol and isopropoxyethanol were classified as skin irritants with the EEC method. Glycol ethers should be handled with all the care that should be taken in the safe use of organic solvents.

An experimental study was conducted in guinea pigs for the predictive assessment of the beryllium alloy hazard in occupational exposure of the skin to beryllium compounds. Guinea pigs were sensitized to beryllium sulfate according to the maximized Magnusson and Kligman test, and challenged with beryllium alloys and metallic copper, beryllium and aluminum samples. Results showed a delayed skin hypersensitivity reaction in 30 to 60% of pre-sensitized guinea pigs challenged with copper-beryllium alloys and aluminum-beryllium alloy. An inflammatory follicular reaction was induced by copper in both controls and pre-sensitized guinea pigs.

Biocides are chemicals used as preservatives added to most cosmetics and toiletries and to industrial water-based products such as cutting fluids, paints and glues. There are numerous biocide formulations used in water-based metalworking fluids. All these products, characterized by a low molecular weight, can react with endogenous proteins and may induce allergic contact dermatitis. Thus, numerous reports on occupational allergic contact dermatitis have been published. The purpose of this experimental study was to compare the sensitizing potential of the various classes of biocides used in metalworking fluids by means of the maximization test of Magnusson & Kligman. The results show that, from the 9 samples tested, 7 biocides induced sensitization varying in grade from moderate to strong, while 2 benzisothiazoline-based samples did not induce allergic contact dermatitis.

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