Chapter 7: Disinfectants and antibacterials · Part 3: Phenols
Thymol
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The worst fact: it's sold as botanical, but Australia classes pure thymol as "Causes severe skin burns and eye damage" and "Harmful if swallowed". Swallowed, it acts like a milder phenol: vomiting, and occasionally convulsions and coma.
Why brands use it: it lets a disinfectant say "plant-based" and still kill germs.
Take care if: you get it on skin or in your eyes, or breathe it.
Comes from: thyme oil, or made synthetically from m-cresol and isopropyl chloride.
Myth check: "Natural means minimum-risk": in the US, thyme oil (not thymol) is on the minimum-risk list, and even a thyme-oil product loses that exemption if it claims to kill disease germs.
Contaminants: nil.
Fair to say: the US EPA knows of no harm when it's used as labelled, and it's a permitted food flavouring.
We use this ingredient. Thymol is a component of the thyme oil in our Curtain Mould Shield. It's sprayed onto curtains and left to dry, not used on skin.
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.
- US EPA. Reregistration documents: chloroxylenol (1994), 2-phenylphenol (2006), p-chloro-m-cresol (1996), o-benzyl-p-chlorophenol (1995), thymol (1993); 40 CFR 152.25.
- HSDB (US National Library of Medicine), via PubChem: manufacturing, toxicity and impurity data.
The full source list is at the end of Chapter 7.