Worth a closer look
Evidence key Strong Moderate Weak How we grade
Chemical of concern Restricted in the EU
- What it can be used for
- Kills or slows microbes, preserves the product, reduces or masks body odor, reduces static and spreads other ingredients evenly (the functions the EU ingredient database, CosIng, lists for it; a product may use it for any of them)
- CAS number
- 63449-41-2, 68391-01-5, 68424-85-1, 85409-22-9
Why it’s flagged
Listed as a chemical of concern by the Campaign for Safe Cosmetics.
- “Quaternary ammonium compounds”. Source: Campaign for Safe Cosmetics
The Campaign for Safe Cosmetics is an advocacy group. Its profiles explain why it considers these ingredients a concern.
Allowed in EU cosmetics only with limits.
- Annex III entry 65; products: Rinse-off hair (head) products; max 3% (as benzalkonium chloride); In the final products the concentrations of benzalkonium chloride, bromide and saccharinate with an alkyl chain of C14, or less must not exceed 0.1% (as benzalk; required warning: Avoid contact with the eyes. Source: EU Cosmetics Regulation, Annex III (restricted)
Annex III (restricted substances) or Annex V (preservatives) of the EU Cosmetics Regulation sets maximum amounts, allowed product types or required warnings.
What the research says
- Quaternary ammonium compounds such as benzalkonium chloride (BAC) and didecyldimethylammonium chloride (DDAC) have been linked to occupational asthma, contact dermatitis and urticaria in healthcare workers, professional cleaners and hairdressers with heavy, repeated exposure to disinfectants, antiseptics and cosmetic preservatives. Moderate evidence. Peyneau 2022
- Benzalkonium chloride was the sixth highest-reacting allergen in a large retrospective patch-testing cohort, and caused contact dermatitis in 7-18.6% of patients using BAC-containing topical medicine for chronic leg ulcers. Moderate evidence. Peyneau 2022
Each finding shows its evidence grade. See every graded fact or how we grade.
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.
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Flagged the same way
Official lists checked September 2026. Spotted a mistake? Tell us.