1 Final Report on the Safety Assessment of Laureths 4 and 23

Abstract

The Laureths, polyethoxyethers of lauryt alcohol, are used in a wide variety of cosmetic products. Laureth-4 was “practically nontoxic” when administered orally to rats and mice. Acute, subchronic, and chronic dermal tests with diluted formulations on rabbits were negative for systemic toxicity. In eye irritation studies in rabbits, undiluted Laureth-4 was moderately and minimally irritating in the unrinsed and rinsed eye, respectively; 10 and 20% dilutions were both classified as minimally and nonirritating. The acute oral LD50s for Laureth-23 were 8.6 and 3.5 g/kg for fasted male rats and mice, respectively. Undiluted Laureth-23 caused no primary irritation when applied to the rabbit skin. Undiluted Laureth-23 caused a slight conjunctival reaction in rabbits. Review of safety test data on closely-related Laureths and other lauryl alcohol ethoxylated compounds indicated no teratological, multiple generation and fertility, and mutagenicity effects for these compounds. No skin irritation or sensitization was reported in clinical studies with undiluted Laureth-4. A 6% Laureth-4 product produced no evidence of phototoxicity. No primary cutaneous irritation was observed in clinical studies using 60% Laureth-23. No evidence of sensitization was reported when a 25% solution of Laureth-23 was used in a repeated insult patch test on 168 subjects, nor was there evidence of phototoxicity when tested on a subset of this population. It is concluded that Laureth-4 and Laureth-23 are safe as cosmetic ingredients in the present practices of use and concentration.