- 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
- 90-43-7
Why it’s flagged
Classified as a skin sensitizer (may cause an allergic skin reaction).
- Skin Sens. 1B (H317). Source: EU CLP Regulation, Annex VI harmonized classification
EU hazard statement H317: may cause an allergic skin reaction.
Classified as a possible or suspected human carcinogen.
- EU classification Carc. 2. Source: EU CLP Regulation, Annex VI harmonized classification
IARC Group 2B means possibly carcinogenic to humans. EU Carc. 2 means suspected human carcinogen. These describe a hazard, not the risk at the amount in one product.
What the research says
- Two no-lye hair relaxer kits marketed for children had the highest measured levels of chemicals banned in EU cosmetics or listed under California's Proposition 65 (DEHP, nonylphenol, o-phenylphenol, diethanolamine) of any products tested in this study. Moderate evidence. Helm 2018
About ingredients flagged like this one:
- In a survey of 187 US pediatric personal-care products, preservatives (57.8% of products) were a more common source of contact allergens than fragrance (29.4%), even though the products were being screened specifically for hypoallergenic/fragrance-related marketing claims. Moderate evidence. Hamann 2015
Each finding shows its evidence grade. See every graded fact or how we grade.
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.