Geraniol: what it is and why it’s flagged

Worth a closer look

Evidence key Strong Moderate Weak How we grade

Labeled fragrance allergen (EU) Skin allergen Scent ingredient Oxidizes into stronger allergens Limited by IFRA

What it can be used for: Adds scent and tones skin (the functions the EU ingredient database, CosIng, lists for it; a product may use it for any of them)
CAS number: 106-24-1

Why it’s flagged

A fragrance allergen the EU requires companies to name on the label.
- Annex III entry 78. Source: EU Cosmetics Regulation, Annex III (restricted)
Must be named on EU labels above 0.001% in leave-on and 0.01% in rinse-off products. Elsewhere, including the US, it can hide inside “fragrance”.
Classified as a skin sensitizer (may cause an allergic skin reaction).
- Skin Sens. 1 (H317). Source: EU CLP Regulation, Annex VI harmonized classification
EU hazard statement H317: may cause an allergic skin reaction.
Used to add scent: its official function is perfuming or fragrance.
- Listed functions: perfuming, tonic. 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.”
Reacts with air to form stronger skin allergens.
- Forms allergenic hydroperoxides when exposed to air. Source: ihateperfume.com graded evidence
These scent chemicals react with air once a product is opened and form hydroperoxides, which are much stronger skin allergens. See the graded evidence below.
Use limited by the fragrance industry's own IFRA standard.
- IFRA standard “Geraniol”: 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

Many fragrance chemicals become stronger skin allergens after the bottle is opened: limonene, linalool and geraniol react with air at room temperature to form hydroperoxides that, in mouse tests, sensitize at 5-10 times lower concentrations than the fresh chemical. Strong evidence. Pastor-Nieto 2021 (Karlberg 2013)
Sanitary pads, panty liners and tampons can contain undisclosed fragrance allergens — chiefly alpha-isomethyl ionone (in every scented tampon tested), hexyl cinnamal and benzyl salicylate, plus trace limonene, linalool and geraniol — and in the EU they do not have to declare any of them. Strong evidence. Pastor-Nieto 2021 (Desmedt 2020)
Common fragrance ingredients such as limonene and geraniol turn into stronger skin allergens when they react with air in an opened bottle. Strong evidence. Khalid & Abdollahi 2021
Seal of Acceptance products must also exclude a named 34-ingredient Ecz-clusion List (including cinnamic alcohol, cinnamic aldehyde, coumarin, eugenol, farnesol, geraniol, hydroxycitronellal, isoeugenol, oak moss absolute and several citrus extracts), chemical UV absorbers other than titanium/zinc/iron physical sunscreens, and formaldehyde releasers, in any amount. Strong evidence. NEA 2026
In a Danish/multi-country test of 25 children's cosmetics and cosmetic-toys, all 7 hydro-alcoholic children's fragrance products (5 eau de toilette, 1 eau de parfum, 1 roll-on deodorant) contained the allergen geraniol, and a separate children's toy-cosmetic perfume-blending kit's lilac essence contained cinnamic alcohol at 3.7% — about 4.6x (the paper's abstract states "by a factor of 5") the IFRA guideline of 0.8%. Moderate evidence. Pastor-Nieto 2021 (Rastogi 1999)
In a 1999 European lab test, all 7 children's hydro-alcoholic fragrance products (eau de toilette, eau de parfum, roll-on deodorant) contained the allergen geraniol, and a children's toy perfume-blending kit's "lilac essence" contained cinnamic alcohol at 3.7% — about 4.6x (the paper's abstract states "by a factor of 5") the industry's own 0.8% safety guideline. Moderate evidence. Rastogi 1999
Essential oils are made largely of the same chemicals labeled as fragrance allergens: supplier data sheets give sweet-orange oil about 95% limonene, lavender oil about 40% linalool and palmarosa oil up to 84% geraniol. Moderate evidence. Klaschka 2016
In human adrenal cells, eight common fragrance terpenes — eucalyptol, geraniol, carvone, 3-carene, ocimene, both pinenes and dihydro-beta-ionone — cut production of the androgen precursor DHEA by 13–31%, and six others cut the activity of aromatase, the enzyme that makes estrogen, by 22–33%. Weak evidence. Sharma 2024

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.

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.

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Flagged the same way

Official lists checked September 2026. Spotted a mistake? Tell us.