A hydroxy-substituted C18 saturated fatty acid (most commonly 12-hydroxystearic acid), typically produced from castor/oleic acid derivatives. It is widely used as a rheology modifier, gellant, and emulsifying aid in cosmetics and industrial formulations; it is not commonly used as a direct food ingredient, though related hydroxy fatty acid derivatives (e.g., from castor oil) are present in some approved additives. Available toxicology and cosmetic safety assessments indicate low acute toxicity and low sensitization potential. If ingested, hydroxy fatty acids are expected to be metabolized via standard fatty-acid β-oxidation pathways.
