Cetrimonium Chloride

Cetrimonium chloride is a quaternary ammonium compound (QAC)—a type of cationic surfactant derived from organic chemistry. In skincare formulations, it functions primarily as a preservative and antimicrobial agent, helping to prevent bacterial and fungal growth that would otherwise compromise product stability and safety.You'll find it in roughly 2.3% of skincare products, often working alongside other preservative systems. Its multiple functions—antimicrobial, antistatic, and emulsifying—make it a multitasking ingredient in formulation.

Cetrimonium chloride works by disrupting the cell membranes of microorganisms. Its positively charged molecular structure allows it to penetrate and damage bacterial and fungal cell walls, preventing them from multiplying. This makes it effective at low concentrations as a preservative system component.On the skin itself, it can also reduce static charge (an antistatic effect), which is why it's sometimes included in leave-on formulations.

Cetrimonium chloride is a formulation ingredient rather than an active you'd apply separately. Simply use your product as directed. If you have a history of contact sensitivity or reactive skin, patch test first, particularly if using multiple products containing QACs simultaneously.

Cetrimonium chloride is generally recognised as safe in cosmetic formulations at typical concentrations. However, it can cause contact dermatitis or irritation in sensitive individuals, especially at high concentrations or on damaged skin. Patch testing is advisable if you have known sensitivity to quaternary ammonium compounds.