Cetyltrimethylammonium chloride better known as Cetrimonium chloride, is a quaternary ammonium compound commonly used as a conditioning agent and preservative in cosmetics and personal care products, particularly in hair care formulations. It is known for its ability to reduce static electricity, soften hair, and enhance detangling, making it a popular ingredient in conditioners, shampoos, and other hair treatments. Cetrimonium chloride is also used for its antimicrobial properties, which help preserve cosmetic products.
Chemical Composition and Structure
Cetrimonium chloride, with the chemical formula C19H42ClN, is a quaternary ammonium salt consisting of a cetyl group (hexadecyl) attached to a nitrogen atom with a positive charge. This positive charge interacts with negatively charged surfaces like hair, making it an effective conditioning agent. The chloride ion serves as a counterion to balance the positive charge of the nitrogen.
Physical Properties
Cetrimonium chloride is typically found as a clear to pale yellow liquid or powder that is soluble in water. It has excellent antistatic and conditioning properties, which make it suitable for improving the feel and manageability of hair. It is commonly used in low concentrations to ensure safe use while providing effective conditioning.

Production Process
Cetrimonium chloride is synthesized through a chemical reaction between cetyl alcohol and trimethylamine, resulting in the formation of the quaternary ammonium compound. The final product is purified for use in cosmetic formulations.
Applications
Hair Conditioners: Cetrimonium chloride is widely used in conditioners, leave-in treatments, and hair masks for its conditioning properties. It helps detangle hair, reduce static, and improve manageability.
Shampoos: In shampoos, it works as a conditioning agent, leaving the hair feeling softer and smoother after washing.
Styling Products: It is also found in hair sprays and styling creams, where it helps to control frizz and static while providing a lightweight feel to the hair.
Preservative: Thanks to its antimicrobial properties, Cetrimonium chloride is sometimes used to help preserve the shelf life of personal care products by preventing microbial growth.
INCI Functions:
Antimicrobial agent. This ingredient is able to suppress or inhibit the growth and replication of a broad spectrum of microorganisms such as bacteria, fungi and viruses by making the stratum corneum temporarily bactericidal and fungicidal.
Antistatic agent. Static electricity build-up has a direct influence on products and causes electrostatic adsorption. The antistatic ingredient reduces static build-up and surface resistivity on the surface of the skin and hair.
Surfactant - Emulsifying agent. Emulsions are thermodynamically unstable and are used to soothe or soften the skin and emulsify, so they need a specific, stabilising ingredient. This ingredient forms a film, lowers the surface tension and makes two immiscible liquids miscible. A very important factor affecting the stability of the emulsion is the amount of the emulsifying agent. Emulsifiers have the property of reducing the oil/water or water/oil interfacial tension, improving the stability of the emulsion and also directly influencing the stability, sensory properties and surface tension of sunscreens by modulating the filmometric performance.
Preservative. Any product containing organic, inorganic compounds, water, needs to be preserved from microbial contamination. Preservatives act against the development of harmful microorganisms and against oxidation of the product.
Cosmetic safety
Restricted cosmetic ingredient as V/44 a Relevant Item in the Annexes of the European Cosmetics Regulation 1223/2009. Substance or ingredient reported: Alkyl (C12-C22) trimethyl ammonium bromide and chloride. Maximum concentration in ready for use preparation 0.1%
Health and Safety Considerations
Safety in Use
Cetrimonium chloride is considered safe for use in cosmetic products when used within recommended concentrations. In the European Union, it is allowed at a maximum concentration of 0.1% in leave-on products and 1.0% in rinse-off products. It is generally well-tolerated by most users, although some individuals with sensitive skin or scalp may experience mild irritation.
Allergic Reactions
While allergic reactions to Cetrimonium chloride are uncommon, it may cause mild irritation, particularly for people with sensitive skin or when used in high concentrations. Patch testing is recommended for individuals with known sensitivities to ingredients in hair care products.
Toxicity and Carcinogenicity
There is no evidence suggesting that Cetrimonium chloride is carcinogenic or toxic at the concentrations approved for cosmetic use. It has undergone safety evaluations and is considered safe for use in personal care products when formulated within regulatory guidelines.
Environmental and Safety Considerations
As with many quaternary ammonium compounds, Cetrimonium chloride is not readily biodegradable, and its release into the environment should be minimized. Proper waste disposal and environmental safety measures are recommended to avoid potential ecological impact, particularly in aquatic environments.
Regulatory Status
Cetrimonium chloride is regulated by cosmetic safety authorities such as the Cosmetic Ingredient Review (CIR) and is approved for use in the European Union, United States, and other global markets. Its use in cosmetics is subject to concentration limits, particularly in rinse-off and leave-on products, to ensure safety.
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Molecular Formula: C19H42ClN C19H42N.Cl
Condensed Formula: CH3(CH2)15N(Cl)(CH3)3
Molecular Weight: 320.0 g/mol
CAS: 112-02-7 68002-63-1
UNII UC9PE95IBP
EC Number: 203-928-6 268-077-5
DSSTox Substance ID: DTXSID6026901 DTXSID2029402
MDL number MFCD00011773
PubChem Substance ID 24857608
Beilstein/REAXYS Number: 3657974
Sinonimi:
- Hexadecyltrimethylammonium chloride solution
- Hexadecyltrimethylammonium chloride
- Palmityltrimethylammonium chloride
- Cetrimonium chloride
- 1-Hexadecanaminium, N,N,N-trimethyl-, chloride
- Cetyltrimethylammonium chloride
- Quaternary ammonium compounds, C14-18-alkyltrimethyl, chlorides
- N,N,N-trimethylhexadecan-1-aminium chloride
- Trimethyl-1-hexadecanaminium chloride
- N-Hexadecyltrimethylammonium chloride
- Adogen 444
- Hexadecyl trimethyl ammonium chloride
- Genamin CTAC
- Cetyl trimethyl ammonium chloride
- Arquad 16
- Trimethylcetylammonium chloride

