Cetearyl, Cetyl, Isostearyl, Myristyl, and Behenyl Alcohols are long-chain aliphatic alcohols that are, at most, only slightly toxic when administered orally at doses of 5 g/kg and greater. In acute dermal toxicity studies (rabbits), doses of up to 2.6 g/kg of Cetyl Alcohol and 2.0 g/kg of a product containing 0.8% Myristyl Alcohol were both practically nontoxic. Mild irritation was observed when a cream containing 3.0% Cetearyl Alcohol was applied to the skin of New Zealand albino rabbits. Cetyl Alcohol (50.0% in petrolatum) applied to abraded and intact skin of albino rabbits produced minimal to slight skin irritation. Cetyl Alcohol was considered to be practically nonirritating when instilled into the eyes of albino rabbits. An aerosol antiperspirant containing 3.0% Myristyl Alcohol induced mild to moderate irritation; a moisturizing lotion containing 0.8% Myristyl Alcohol was nonirritating to rabbit eyes. Corneal irritation was reported following an ocular test using a 5.0% Isostearyl Alcohol antiperspirant. Conjunctival irritation was observed 2 and 6 h after instillation of 1.0% Behenyl Alcohol. Isostearyl Alcohol (5.0% in propylene glycol) and an antiperspirant containing 5.0% Isostearyl Alcohol were not sensitizers in guinea pigs. Cetyl Alcohol was not mutagenic in Salmonella typhimurium LT2 mutant strains in the spot test. Clinical skin irritation and sensitization studies of product formulations containing up to 8.4% Cetyl Alcohol produced no evidence of irritation or sensitization. Moisturizing lotions containing 0.8% Myristyl Alcohol were nonirritating to human skin, and moisturizers containing 0.25% Myristyl Alcohol were neither irritants nor sensitizers. No signs of skin irritation or sensitization were observed in humans following the dermal application of 25% Isostearyl Alcohol. In a human skin sensitization study of a cream containing 3.0% Cetearyl Alcohol, none of the subjects had positive reactions. An analysis of the data and comparison with data from other toxicity studies on long-chain aliphatic alcohols is presented. Based on the available data included in this report, it is concluded that Cetearyl Alcohol, Cetyl Alcohol, Isostearyl Alcohol, Myristyl Alcohol, and Behenyl Alcohol are safe as cosmetic ingredients in the present practices of use.