Summary Among the warnings which are now necessary in Europe for the protection of the consumer and which must appear on the packagings of cosmetic and corporal hygiene products, there is one concerning lanolin. The regulation requires the mention 'Important, this product contains lanolin'. Cutaneous allergic reactions have been reported in the last few years after application of products containing lanolin or lanolin derivatives although lanolin has been used for a long time. The paper describes tests of cutaneous hypersensitivity on the guinea-pig with lanolin, lanolin alcohol and a semi-liquid lanolin. No reaction was observed with a purified lanolin, even if it was old. A weak allergenic effect was shown with the semi-liquid derivative. Sensitization reactions were observed with a sample of lanolin fatty alcohols. These results were analysed and compared to those published in literature.