Chapter 6: Preservatives
Bronopol
- Contaminant risk
The worst fact: it releases formaldehyde, a known cause of cancer. Washington State bans it in cosmetics from 1 January 2027. It can also form nitrosamines (another group of cancer-causing chemicals) when mixed with certain other ingredients.
Why brands use it: it works at low levels (the EU caps it at 0.1%).
Take care if: you're allergic to formaldehyde, or for your eyes. The raw chemical is severely damaging to eyes.
Comes from: made in a lab. It's fully synthetic.
Myth check: "it's a strong skin allergen": not on its own, says Australia's regulator.
Contaminants: formaldehyde and nitrosamines. Formaldehyde forms faster in hot or alkaline products, and nitrosamines only with certain other ingredients. They're unlikely in a well-made product, but it's a factor you can't see on the label.
Fair to say: Australia's regulator says it breaks down slowly enough that the formaldehyde is unlikely to be a risk.
Correct as of November 2026. What the badges mean
Sources
- Safe Work Australia. Hazardous Chemical Information System (HCIS): classifications for each chemical and for benzene, ethylene oxide, toluene, phenol and benzyl chloride. hcis.safeworkaustralia.gov.au
- NICNAS (now AICIS). Isothiazolinones: Human health tier III assessment (2020); Methylchloroisothiazolinone IMAP assessment (2019); Bronopol IMAP assessment 1504 (2014). industrialchemicals.gov.au
The full source list is at the end of Chapter 6.