- CAS number
- 137-58-6
Why it’s flagged
Prohibited in cosmetics in the EU.
- Annex II entry 399. Source: EU Cosmetics Regulation, Annex II (prohibited)
Annex II of the EU Cosmetics Regulation lists substances that must not be used in cosmetics sold in the EU.
What the research says
- In a small double-blind lab test, a drug that numbs sensory nerves (lidocaine) cut in half the number of coughs that chemically sensitive patients had after inhaling capsaicin, evidence that their airway sensitivity runs through nerve pathways rather than the kind of airway narrowing seen in asthma. Moderate evidence. Millqvist 2000
About ingredients flagged like this one:
- The EU bans more than 1,400 substances from cosmetics, while US rules restrict only a handful. Moderate evidence. Alblooshi 2025
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.