Quaternium-18 ●
TL;DR. It is a cationic conditioning and antistatic agent used mainly in hair care, where it helps reduce static, improve combing, and leave a coated, softened feel on fibers.
What does Quaternium-18 do in a cosmetic formula?
It is a cationic conditioning and antistatic agent used mainly in hair care, where it helps reduce static, improve combing, and leave a coated, softened feel on fibers.
Is Quaternium-18 clean?
Clean-beauty standards often flag this ingredient because it belongs to a conventional cationic conditioning class with sensitization and residue concerns, and some versions may use animal-derived fatty chains. It is not a typical choice for stricter natural-positioned formulas.
Is Quaternium-18 sustainable?
This material has historically been made from tallow-derived long-chain fatty feedstocks plus synthetic nitrogen chemistry. It is not considered readily biodegradable in many screening frameworks, and cationic surfactants can bind strongly to sludge and sediments, which raises aquatic-impact concerns.
Is Quaternium-18 COSMOS-approved?
It is not permitted under COSMOS-organic or COSMOS-natural as a conventional synthetic cationic conditioner. Its fit with Green Chemistry is weak because of limited biodegradability, possible animal-derived sourcing, and reliance on reactive processing rather than simple renewable conversion.
How does Quaternium-18 work chemically?
The molecule is amphiphilic, with a permanently charged nitrogen center and two long hydrophobic chains, so it adsorbs strongly to negatively charged hair and improves wet and dry combing. It is typically used at low percentages in rinse-off conditioners and styling products, is stable across normal cosmetic pH ranges, and is incompatible with anionic surfactants or polymers that can form insoluble complexes.
Last updated 2026-08-19