Chapter 2: Other surfactants · Part 2: Cationic surfactants (fabric softeners)
TEA esterquat
- Made from a hazardous chemical
The worst fact: it works against towels. While softener quats "do soften fabrics very effectively, they also can make them less absorbent".
Why brands use it: it softens fabric. EU industry data put esterquats at 3.5 to 5.1% in regular liquid softener, 11.2 to 23% in concentrates and 25% in dryer sheets. An esterquat (identity confidential) assessed in Australia in 2011 was to be used at up to 15%.
Take care if: you want absorbent towels, or need a garment's flame resistance (see the caution above). Undiluted softener in the eye may cause mild irritation that fully reverses.
Comes from: fatty acids, mostly from tallow or palm oil, joined to triethanolamine, then quaternised with dimethyl sulfate. Australia classes dimethyl sulfate as "Suspected of causing genetic defects; May cause cancer". That doesn't mean it's in the product, but it's not a great starting point for something you clean with.
Myth check: no common myth we could source.
Contaminants: nil. (We found no published data on leftover dimethyl sulfate.)
Fair to say: an EU review found "not a single case of documented skin sensitization to any of the esterquats". It breaks down fast: more than 99% of a test solution had been split by water (hydrolysed) within 5 hours 25 minutes.
Correct as of November 2026. What the badges mean
Sources
- Safe Work Australia. Hazardous Chemical Information System (HCIS): classifications for alcohol ethoxylates, C10-12 alcohol EO/PO, cocamidopropyl betaine, nonylphenol, DODMAC, and for ethylene oxide, propylene oxide, dimethyl sulfate, methyl chloride, benzyl chloride, epichlorohydrin, DMAPA, monochloroacetic acid and 1,4-dioxane.
- NICNAS/AICIS. IMAP Tier II assessments: ethoxylated aliphatic alcohols (2019); alkoxylated aliphatic alcohols (2020); nonylphenols; nonylphenol ethoxylate sulfate and phosphate esters (environment, 2016); cationic surfactants; mono- and dialkyl quaternary ammonium compounds (environment, 2016); cocamidopropyl betaine; fatty acid amidopropyl dimethylamines. Public reports STD/1386 (esterquat, 2011) and STD/1363 (lauryl hydroxysultaine).
- HERA. Alcohol ethoxylates (2009); esterquats (environment 2008, human health 2009); cocamidopropyl betaine (2005); fatty acid salts (2002).
- Mishra S, Tyagi VK. Esterquats: the novel class of cationic fabric softeners. J Oleo Sci 2007.
- Guo J. Effects of fabric softener on the flammability of cotton and polyester fabrics. MS thesis, Virginia Tech, 2003.
The full source list is at the end of Chapter 2.