Hexadecanedioic acid

Hexadecanedioic acid (CAS 505-54-4) is a long-chain saturated dicarboxylic acid, also known as thapsic acid or hexadecane diacid, with the molecular formula C16H30O4. It carries no assigned E-code and is registered under EC 208-013-5. It is commercially referenced under synonyms including NSC 15164 and dicarboxylic acid C16.

In personal care formulations, it functions as an emulsifier and hair conditioner by anchoring to both aqueous and lipid phases through its dual carboxyl groups, improving emulsion stability and deposit on the hair shaft. In metalworking lubricants, its linear C16 backbone reduces interfacial friction by forming a structured boundary layer on metal surfaces.

Hexadecanedioic acid is supplied as a solid and is subject to REACH registration requirements for EU import and use. Procurement teams should confirm grade specification against intended application, as purity thresholds differ between cosmetic and industrial lubricant uses. Standard packaging formats vary by supplier volume tier.