Take the Quiz - Get 15% OFF your 1st Order
Search

Chapter 7: Disinfectants and antibacterials · Part 1: Quats

Cetrimonium chloride

No badge

Also called
CTAC, hexadecyltrimethylammonium chloride
Found in
disinfectant and cleaning products, hair conditioner

The worst fact: a 5% solution in rabbits' eyes caused corneal clouding, iris inflammation and irritation in every treated eye, and at 24 to 30% the damage was irreversible. Commercial raw material is sold at 24 to 30%. Quats of its type were the most abundant in people's blood during the pandemic.

Why brands use it: it kills germs, preserves products, and in conditioners smooths hair and stops static.

Take care if: you get it in your eyes. Australia classes it as "Harmful if swallowed; Harmful in contact with skin; Causes severe skin burns and eye damage". Quats are Schedule 5 (Caution) above 5% and Schedule 6 above 20%. EU cosmetics cap it at 2.5% in rinse-off hair products, 1% in leave-on hair products and 0.5% in leave-on face products, and 0.1% when it's used as a preservative.

Comes from: hexadecylamine and methyl chloride, or cetyl chloride and trimethylamine.

Myth check: "It's gentle, it's in conditioner": only because it's dilute. The raw material is corrosive.

Contaminants: nil.

Fair to say: Europe's safety committee found no risk to consumers within the EU limits, and it isn't classed as a skin allergen.

Correct as of November 2026. What the badges mean

Sources

  • Australian Government. Poisons Standard October 2026 (SUSMP), F2026L01327: didecyldimethylammonium salts; quaternary ammonium compounds; triclosan; o-phenylphenol; chlorocresol; p-dichlorobenzene; thymol; methanol; Appendix B.
  • Safe Work Australia. Hazardous Chemical Information System (HCIS): classifications for each chemical, and for benzene and benzyl chloride.
  • NICNAS. IMAP: cationic surfactants (2015). Priority Existing Chemical Assessment Report No. 30: triclosan (2009).
  • European Union. Regulation (EU) 474/2014 (1,4-dichlorobenzene); Implementing Decision (EU) 2016/110 (triclosan); Regulation (EU) 358/2014 (triclosan in cosmetics); Regulation (EU) 2019/831 (chlorophene); Regulation (EU) 2014/866 (cetrimonium chloride).
  • European Commission SCCS. Opinions on alkyl trimethylammonium chlorides (2009) and triclosan (2010).
  • HSDB (US National Library of Medicine), via PubChem: manufacturing, toxicity and impurity data.
  • Zheng G et al. Quaternary ammonium compounds in human blood during the COVID-19 pandemic. Environ Sci Technol 2021;55:14689-14698.

The full source list is at the end of Chapter 7.