Chlorphenesin is known for its excellent antimicrobial, antifungal properties activated in combination with other preservatives. It has a good skin tolerance at the accepted concentration in cosmetic products, even if it is regarded to be a rare cosmetic allergen because of the report of some cases of allergic contact dermatitis. It has also been described as a relaxant for skeletal muscle. 

A recent study conducted the photolysis experiments of chlorphenesin in an aqueous solution and on a cream used in cosmetics. Three by-products formed from the direct UV-visible photodegradation of chlorphenesin were illustrated by chromatography (gas and liquid) coupled with tandem mass spectrometry (GC-MS/MS and LC-HR MS/MS) and discovered in both solutions. In vitro tests on Vibrio fischeri bacteria displayed an increase in the overall ecotoxicity of chlorphenesin with increasing irradiation time in both samples. In silico QSAR (Quantitative Structure Activity Relationship) tests were conducted using T.E.S.T. (Toxicity Estimation Software Tool). Among the degradation compounds recognised, 4-chlorophenol must contribute to the increased ecotoxicity of the photolyzed solution as the in silico LC50 estimated for all tests conducted are always more inferior than those obtained for chlorphenesin.

SOURCE- Ouaghrem MB, de Vaugelade S, Bourcier S, Genty C, Pirnay S, Bouchonnet S. Characterization of photoproducts and global ecotoxicity of chlorphenesin: A preservative used in skin care products. International Journal of Cosmetic Science. 2022 Feb;44(1):10-19. https://doi.org/10.1111/ics.12760