Bronopol
برونوبول
Formaldehyde-releaser preservative · CAS: 52-51-7
An effective but formaldehyde-releasing preservative; fine in rinse-off, worth avoiding for the formaldehyde-sensitive.
Why this verdict
GHS-hazardous (sensitiser/corrosive/tox) but a legitimate active - flagged.
What It Is
A preservative (bronopol) that works by slowly releasing tiny amounts of formaldehyde to stop microbial growth.
It's effective and cheap, but it belongs to the 'formaldehyde-releaser' family - it preserves products by slowly giving off trace formaldehyde, a known skin sensitiser and classified carcinogen. That's fine sealed in a rinse-off cleaner, but it's exactly why these preservatives are increasingly avoided in leave-on products and by formaldehyde-sensitive people. Worth recognising on a label.
Evidence & Status
IARC Carcinogen Group
Not classified
EU Status
CLP-classified (H302, H312, H315, H318, H335, H400); signal word Danger.
US · FDA Status
EPA/FDA-reviewed where applicable
Cleaning & Hazard
Hazard signal
Danger
Hazard codes (GHS)
H302, H312, H315, H318, H335, H400
Environmental note
Very toxic to aquatic life (H400) - surfaced as a fact.
Do not mix
Should not be formulated alongside nitrosating agents - can form nitrosamines.
Halal Status: Halal
Synthetic; no animal-fat or alcohol concern (surface use).
Worth Knowing
Also Known As
2-bromo-2-nitropropane-1 · 3-diol · BNPD
Primary Source
Evidence, not medical advice. You decide.
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