Salicylic Acid

Salicylic Acid is an aromatic acid.^[1] In cosmetics, it is used to reduce the appearance of dandruff on the scalp, smooth and detangle hair by reducing tangling and rough feel, and soften hardened dead skin so it can be shed more easily.^[4] It is also used to keep an ingredient’s characteristic odor or taste from becoming too noticeable, slow product spoilage during storage by inhibiting microbial growth, and leave the skin feeling soft and smooth.^[4] In Europe, when used as a preservative, it is permitted at up to 0.5% (calculated as acid).^[2] However, it cannot be used in products for children under 3 years of age.^[2] When used for purposes other than preservation, it may be used at up to 3.0% in rinse-off hair products; up to 2.0% in other products except body lotions, eyeshadows, mascaras, eyeliners, lipsticks, and roll-on deodorants; and up to 0.5% in body lotions, eyeshadows, mascaras, eyeliners, lipsticks, and roll-on deodorants. It also cannot be used in products for children under 3 years of age, in spray applications where users may inhale it and expose their lungs to it, or in oral products.^[2] It is described as a white to pale yellow solid with no distinct odor, so it is important to first determine whether it dissolves more readily in water or oil and dissolve or disperse it in the appropriate phase to help create a uniform formulation.^[3]