Cetrimonium Chloride (CTAC) - CAS 112-02-7

Cetrimonium Chloride (CTAC) - Properties, Applications, and Safety

Cetrimonium chloride (CAS 112-02-7), also known as cetyltrimethylammonium chloride or hexadecyltrimethylammonium chloride, is a quaternary ammonium salt belonging to the family of cationic surfactants. It is widely used in cosmetic, personal care, and industrial applications due to its excellent conditioning, antistatic, and emulsifying properties.

Chemical and Physical Properties

Cetrimonium chloride has the molecular formula C₁₉H₄₂ClN and a molecular weight of approximately 320.0 g/mol. It typically appears as a white to off-white powder, flakes, or a 25–30% aqueous solution, with a mild, characteristic odor. Key properties include:

• Density: Approximately 0.98 g/cm³ at 20°C (for solutions)

• Melting Point: 237°C (decomposes)

• Flash Point: Not applicable

• pH (1% aqueous solution): 5.0–7.0

• Solubility: Readily soluble in water and ethanol; compatible with cationic and nonionic surfactants; incompatible with anionic surfactants (forms precipitates)

Mechanism of Action

As a cationic surfactant, cetrimonium chloride carries a positive charge that enables strong electrostatic adsorption to negatively charged surfaces such as hair keratin, skin, and fabrics. When applied to hair, it neutralizes static electricity, reduces friction between hair fibers, and forms a lubricious, hydrophobic film that improves wet and dry combability, enhances softness, and imparts shine. On microbial cells, the cationic head group disrupts membrane integrity, contributing to its antimicrobial and preservative properties.

Applications

Hair Care: Cetrimonium chloride is one of the most widely used conditioning agents in shampoos, conditioners, hair masks, leave-in treatments, and styling products. It improves wet combing, reduces static and flyaway, enhances softness and shine, and protects against mechanical damage. It is particularly effective in formulations for dry, damaged, or chemically treated hair.

Skin Care: Used in creams, lotions, and moisturizers as a mild conditioning agent and emulsion stabilizer.

Fabric Care: Functions as a fabric softener and antistatic agent in rinse-cycle fabric conditioners and industrial textile processing.

Disinfectants and Preservatives: At higher concentrations, it is used as an antiseptic and preservative in topical formulations, disinfectant solutions, and ophthalmic preparations.

Safety and Toxicology

The Cosmetic Ingredient Review (CIR) Expert Panel has confirmed the safety of cetrimonium chloride for use in cosmetics at recommended concentrations. Typical use levels are 0.1–0.5% in rinse-off products and up to 1% in leave-on products. At higher concentrations, it may cause mild skin and eye irritation. It is not considered a skin sensitizer at typical use levels. The compound is incompatible with anionic surfactants and may precipitate in their presence.

Environmental Profile

Cetrimonium chloride is classified as hazardous to the aquatic environment and is toxic to aquatic organisms with long-lasting effects. It is poorly biodegradable under aerobic conditions; however, it is adsorbed to sludge during wastewater treatment. The compound does not have significant bioaccumulation potential.

Storage and Handling

Cetrimonium chloride should be stored in tightly sealed containers at 5–30°C, protected from moisture and strong oxidizing agents. Use appropriate personal protective equipment (gloves, safety goggles) when handling concentrated solutions. In case of contact with skin or eyes, rinse thoroughly with water.

Conclusion

Cetrimonium chloride (CTAC, CAS 112-02-7) is a versatile and effective cationic surfactant widely used in hair care, skin care, and fabric care formulations. Its excellent conditioning, antistatic, and emulsifying properties make it a key ingredient in modern personal care products. When used within recommended concentrations and properly formulated, it is considered safe and well-tolerated. Continued use and research are expected to further optimize its applications while addressing environmental considerations.