Phenoxyethanol is a preservative used in cosmetics and personal care products. It is a biocide which is most active against Gram-negative bacteria. It is generally used in combination with other preservatives, in part because its activity is weak against yeast and mold.
Phenoxyethanol is stable up to 85°C (185°F) and has useful activity from pH 3 to 10. Phenoxyethanol is soluble in most oils. It is also soluble in water from 0.5 to 2.67 grams per 100 grams of water. It is miscible with propylene glycol and glycerin.
Phenoxyethanol is inactivated by highly ethoxylated compounds. In surfactant solution systems, the water must be saturated with Phenoxyethanol for activity. If the level is too low, it acts as a nutrient for bacteria.