Ceteareth-30 is the polyethylene glycol ether of cetearyl alcohol. It is typically sold as odorless white flakes. Ceteareth ingredients are chemically alkyl PEG (polyethylene glycol) ethers and can be found in skin care products, moisturizers, hair conditioners, suntan, and indoor tanning products, as well as hair dyes, colors, and tints. It is difficult to determine the molecular weights and physical properties of ceteareth ingredients as they are the mixtures of two molecules in unknown ratios. Ceteareth-30 is a non-ionic emulsifier and surfactant.
Origin
Alkaline catalysis is by far the most common method of manufacture of alkyl PEG ethers, although acid catalysis is known. The initiation of the alkaline catalyzed synthesis of alkyl PEG ethers consists of the addition of ethylene oxide to a dry solution of the appropriate alcohol (eg, cetearyl alcohol is used to synthesize ceteareths) with an alkali earth metal (eg, potassium hydroxide) or alkoxide (eg, sodium methoxide). The reaction continues to propagate (ie, continues to add additional units of ethylene glycol to the alcohol) until the available ethylene oxide is consumed and/or the reaction is terminated by the addition of an acid (eg, hydrochloric acid). Dioxane (1,4- diethylene dioxide; 1,4-dioxane) is commonly formed as a by-product. Finally, 1 or more oxidizing agents (e.g., hydrogen peroxide) or antioxidants or stabilizers (e.g., butylated hydroxytoluene [BHT] or a-tocopherol [vitamin E]) are commonly used as a finishing step.
Safety profile
The safety of the ceteareth ingredients has been assessed by the Cosmetic Ingredient Review (CIR) Expert Panel. The CIR Expert Panel evaluated the scientific data and concluded that ceteareth-30 is safe for use in cosmetics and personal care products. Ceteareth ingredients should not be used on damaged skin. CIR Safety Review: The CIR Expert Panel considered previous findings from the safety assessment of Polyethylene Glycol (PEG), several fatty alcohols (Cetearyl Alcohol, Cetyl Alcohol, and Stearyl Alcohol), and Steareths to supplement the data on the Ceteareth ingredients. These data indicated little evidence of toxicity. Data on the PEG ingredients indicated that, when used on burn patients, PEGs may result in kidney effects. Therefore, the CIR Expert Panel also concluded that the ceteareth ingredients should not be used on damaged skin. The ceteareth ingredients may be used in cosmetics and personal care products marketed in Europe according to the general provisions of the Cosmetics Regulation of the European Union.