Red flag
Releases formaldehyde Chemical of concern
- Also on labels as
- Bronopol
- What it can be used for
- Preserves the product (the functions the EU ingredient database, CosIng, lists for it; a product may use it for any of them)
- CAS number
- 52-51-7
Why it’s flagged
Formaldehyde-releasing preservative.
- EU rules require the label warning “releases formaldehyde” above a set level. Source: EU Regulation 2022/1181 (formaldehyde releasers)
These preservatives slowly release formaldehyde into the product. The EU classifies formaldehyde as a carcinogen and a skin sensitizer, and requires a “releases formaldehyde” warning above a set level.
Listed as a chemical of concern by the Campaign for Safe Cosmetics.
- “Formaldehyde and formaldehyde-releasing preservatives”. Source: Campaign for Safe Cosmetics
The Campaign for Safe Cosmetics is an advocacy group. Its profiles explain why it considers these ingredients a concern.
What this page can’t tell you
These lists describe what a substance can do, its hazard. The risk from one product depends on how much is in it and how you use it, and the label doesn’t say how much.
Not being on a list doesn’t make an ingredient safe. It may never have been assessed.
Check your products
Check a whole labelProducts that list itEWG Skin DeepShop fragrance-free
“Products that list it” opens Open Beauty Facts, a free database anyone can edit.
Flagged the same way
Official lists checked September 2026. Spotted a mistake? Tell us.