Red flag
Evidence key Strong Moderate Weak How we grade
Banned in EU cosmetics Cancer classification Suspected genetic damage 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
- 75-07-0
Why it’s flagged
Prohibited in cosmetics in the EU.
- Annex II entry 1391. 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.
Classified as a known or probable human carcinogen.
- EU classification Carc. 1B. Source: EU CLP Regulation, Annex VI harmonized classification
IARC Group 1 means carcinogenic to humans, Group 2A probably carcinogenic. EU Carc. 1A means known, 1B presumed to cause cancer in humans. These describe a hazard, not the risk at the amount in one product.
Classified as suspected of causing genetic defects.
- EU classification Muta. 2. Source: EU CLP Regulation, Annex VI harmonized classification
EU Muta. 2: suspected of causing genetic defects.
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: fragrance. 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
- 4 of the 6 products released at least one chemical the Clean Air Act classifies as a hazardous air pollutant (acetaldehyde, chloromethane or 1,4-dioxane), and none was listed. Moderate evidence. Steinemann 2009
- A car air freshener's own terpenes (alpha-pinene, beta-pinene, p-cymene, limonene) react with in-vehicle ozone to form ultrafine particles and irritant gases (formaldehyde, acetaldehyde, acrolein) that never appear on the product's ingredient list, because they are made in the cabin air, not sold in the bottle. Moderate evidence. Lamorena & Lee 2008 (J Hazard Mater)
- 11 of 25 best-selling fragranced products (44%) released at least one chemical the EPA classes as a probable cancer-causing air pollutant, such as acetaldehyde or 1,4-dioxane, though the study couldn't tell whether these came from the fragrance or the rest of the formula. Moderate evidence. Steinemann 2011
- Acetaldehyde, a possible human carcinogen (IARC Group 2B), was released by 23 of 42 baby products and was never listed on any label. Weak evidence. Nematollahi 2018
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.
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.