Euxyl K903

Euxyl K903 is a liquid broad-spectrum preservative for cosmetics with an acidic pH. It protects water-containing products against bacteria, yeasts and moulds and is used in creams, lotions, shampoos, shower gels and wet wipes, that is, in both rinse-off and leave-on products. The manufacturer developed it for formulations with a pH up to 6 and according to its data it is effective particularly in non-ionic systems. The base of the blend is benzyl alcohol supplemented with benzoic acid and dehydroacetic acid; the blend also contains tocopherol. The raw material is synthetic, but according to the manufacturer the composition meets the requirements of several natural and certified cosmetics standards. The preservative is paraben-free and holds Vegan and Halal certifications. Key properties Broad spectrum of activity – according to the manufacturer it acts evenly against bacteria, yeasts and moulds. Activity in the vapour phase too – the manufacturer reports good efficacy also in the headspace above the product surface. Leave-on and rinse-off products – the same raw material for a cream, toner, shampoo and shower gel. Wet wipes – the manufacturer also recommends it for emulsions and solutions used for saturating wipes. Liquid form – measured and blended without dissolving a powder; added only to the cooled phase. Readily biodegradable – according to OECD 301. Use in formulation The recommended dosage is 0.4–1.2 % by weight of the finished product. In the manufacturer's tests, 0.8 % was sufficient in a natural face cream at pH 5.5 to meet challenge test criteria. For an emulsion