- What it can be used for
- Adds flavor and adds scent (the functions the EU ingredient database, CosIng, lists for it; a product may use it for any of them)
- CAS number
- 122-78-1
Why it’s flagged
Used to add scent: its official function is perfuming or fragrance.
- Listed functions: flavoring, fragrance, 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.”
Use limited by the fragrance industry's own IFRA standard.
- IFRA standard “Phenylacetaldehyde”: use limited. Source: IFRA Standards Library
IFRA, the fragrance industry's own standards body, sets maximum amounts for this material in different kinds of products.
What the research says
- The fragrance industry's original 1976 evidence for aldehyde 'quenching' (that a companion terpene or alcohol stops citral, cinnamic aldehyde or phenylacetaldehyde from causing skin sensitization) was a single, unreplicated human maximization test per mixture with no subject numbers reported, and the paper's own data are internally inconsistent: cinnamon bark oil sensitized despite being one of the paper's three 'protective natural oil' examples, and cinnamic aldehyde + eugenol sensitized at a 2.5:1 ratio where 1:1 had not. Moderate evidence. Opdyke 1976 (RIFM) Industry-funded
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.