Abstract
The Ceteth family of ingredients are the polyethylene glycol (PEG) ethers of cetyl alcohol. They are manufactured by the ethoxylation of cetyl alcohol with the number of moles of ethylene oxide corresponding to the average polyethylene glycol chain length desired. Not all of the polymer chain lengths covered in this assessment are currently reported to be used, but all are listed as cosmetic ingredients and may have been used in the past and could be used in the future. Ceteths are surfactants used as emulsifying, cleansing, and solubilizing agents in cosmetic formulations. Limited safety test data are available on ingredients in the Ceteth family, all consistent with surfactant properties. In separate studies, 2.5% Ceteth-2 was irritating to abraded skin, but 3.0 % was not irritating to intact skin. Dose-dependent irritation was noted for Ceteth-2 and Ceteth-10 at concentrations ranging from 5% to 100%. Ceteth-20 was found to enhance transposition of a marker from phage λ to bacterial DNA. Toxicity data, including reproductive and developmental toxicity, carcinogenesis data, and clinical testing data, available from previous safety assessments on Polyethylene Glycol and Cetyl Alcohol, were summarized. Although PEGs were mild irritants/sensitizers, there was evidence of nephrotoxicity in burn patients exposed to PEGs, and no such effects were seen in animal studies on intact skin. This led to a recommendation that PEGs not be used on damaged skin. Irritant effects of Ceteths on abraded skin not seen with intact skin likewise suggested that cosmetic manufacturers should not use Ceteths in products that may be used on damaged skin. Although metabolites of ethylene glycol monalkyl ethers are reproductive and developmental toxins, it was considered unlikely that the relevant metabolites would be found in or produced from the use of Ceteths in cosmetic formulations. Of concern was the possible presence of 1,4-dioxane and ethylene oxide impurities. The importance of using the necessary purification procedures to remove these impurities was stressed. Inhalation of Cetyl Alcohol at 26 ppm for 6 hours caused mucosal irritation, but shorter exposures at a concentration of 9.6 mg/L caused no irritation. Based on this data and with particle size and cosmetic use concentrations, Ceteths were considered to be safe for aerosolized use. Based in part on the limited data available on Ceteths included in the report and on the previous reviews of the two components found in Ceteths, it was concluded that Ceteth-1, -2, -3, -4, -5, -6, -10, -12, -14, -15, -16, -20, -24, -25, -30, and -45 are safe in the present practices of use.