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Citral

Worth a closer look

Evidence key Strong Moderate Weak How we grade

Labeled fragrance allergen (EU) Skin allergen Scent ingredient Limited by IFRA

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
5392-40-5

Why it’s flagged

  • A fragrance allergen the EU requires companies to name on the label.

    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).

    EU hazard statement H317: may cause an allergic skin reaction.

  • Used to add scent: its official function is perfuming or fragrance.

    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, the fragrance industry's own standards body, sets maximum amounts for this material in different kinds of products.

What the research says

  • The industry once allowed the allergen citral only if mixed with a companion terpene (originally tested at about 20% d-limonene, later mandated at ≥25%), claiming the terpene 'quenched' the allergic reaction; the original 1976 evidence for this was a single unreplicated human test with no subject numbers reported and was already internally inconsistent, later industry HRIPTs could not reproduce quenching for a related aldehyde (cinnamaldehyde), and air-oxidized limonene, the proposed quencher, is itself now one of the commonest fragrance allergens (about 5% of patients tested). Strong evidence. Ford 1994 (RIFM) Industry-funded
  • 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
  • People with chronic, treatment-resistant hand eczema and a history of reacting to scented products can ask their dermatologist for patch testing beyond the standard fragrance mix, including citral, Lyral, hydroxycitronellal and oxidized limonene/linalool. Moderate evidence. Heydorn 2003 Industry-funded

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.

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.