Worth a closer look
Evidence key Strong Moderate Weak How we grade
Possible carcinogen Scent ingredient
- What it can be used for
- Adds scent (the functions the EU ingredient database, CosIng, lists for it; a product may use it for any of them)
- CAS number
- 100-41-4
Why it’s flagged
Classified as a possible or suspected human carcinogen.
- IARC Group 2B (possibly carcinogenic to humans). Source: IARC Monographs list of classifications
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.
Used to add scent: its official function is perfuming or fragrance.
- Listed functions: perfuming. Source: EU CosIng ingredient database
The EU ingredient database (CosIng) lists this ingredient's function as perfuming or fragrance, so it may be there to add scent, even on a label that never says “fragrance.”
What the research says
- Choose unscented feminine hygiene products rather than relying on organic or natural labels, and avoid frequent vaginal douching and feminine powder use: scented tampons had far more terpenes in product testing, and a separate NHANES biomarker study found frequent douching (2+ times/month) linked to 81% higher blood 1,4-dichlorobenzene (dose-response, p=0.04) and feminine powder use linked to 36% higher blood ethylbenzene. Moderate evidence. Lin 2020
- Using feminine powder in the past month was linked to 36% higher blood ethylbenzene in a nationally representative NHANES sample of reproductive-aged women. Moderate evidence. Ding 2020
Each finding shows its evidence grade. See every graded fact or how we grade.
Don’t want it on you or in your air? Look for “fragrance-free,” not “unscented.” An unscented product can still contain a masking fragrance. Why the words matter.
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.
“Fragrance” or “parfum” on a label can hide this ingredient and many others. In the US, the individual chemicals in a fragrance are rarely named on the label.
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.