Ingredient file · Banned

Is quaternium-15 banned in cosmetics?

Q: What does EWG Skin Deep say about quaternium-15?

EWG Skin Deep scores quaternium-15 8 out of 10 with limited data, and lists use restrictions as moderate. Read 23 October 2026.

Yes, in the EU: Annex II lists quaternium-15 as a prohibited substance (entry 1385). California, the EU and FDA's named list, read 23 October 2026, with EWG Skin Deep's score.

SlipperSkin finding

Read on 23 October 2026, quaternium-15 is prohibited in the EU (Annex II) and banned in California; EWG Skin Deep scores it 8 out of 10.

From the California statute, the EU Cosmetics Regulation as consolidated on 1 May 2026, FDA’s page and EWG’s ingredient page, read 23 October 2026. We report what each says; we do not rate the ingredient.

Is quaternium-15 banned in cosmetics?

Yes, in the EU: Annex II lists quaternium-15 as a prohibited substance (entry 1385). California bans it from 1 January 2025 (list (a)(6)). FDA's named list does not include it. EWG Skin Deep scores it 8 out of 10 (data: limited).

Quaternium-15: where it standsread 23 October 2026

Filled red marks a ban, blue a restriction, pale an ingredient that list does not name. FDA's page names 11 entries and none is quaternium-15. The EWG row marks its score; a bar shows a range.

What does the EU list say about quaternium-15?

Annex II is the EU's list of prohibited substances. The entries for quaternium-15 are in the table below, as printed in the regulation consolidated on 1 May 2026.

Quaternium-15 in the EU Cosmetics Regulation, found by CAS number 51229-78-8
Where	Annex	Cap, threshold and product type	Condition
Annex II, entry 1385 as printed: Cis-1-(3-chloroallyl)-3,5,7- triaza-1-azoniaadamantane chloride (cis-CTAC)	Prohibited substances	prohibited all cosmetic products	No condition printed in the entry.
Annex II, entry 1386 as printed: Cis-1-(3-chlorallyl)-3,5,7-triaza-1-azoniaadamantane chloride (cis-CTAC), quaternium-15	Prohibited substances	prohibited all cosmetic products	No condition printed in the entry.

Is quaternium-15 on California's banned list?

Yes. California's Health and Safety Code section 108980 bans quaternium-15 from 1 January 2025 (list (a)(6)), when intentionally added.

What does EWG Skin Deep say about quaternium-15?

EWG’s page gives quaternium-15 a hazard score of 8 out of 10 with limited data. Its concerns line reads, in part: Use restrictions (moderate), Neurotoxicity (low), Endocrine disruption (low), Persistence and bioaccumulation (moderate), Non-reproductive organ system toxicity (low_moderate), Irritation (skin, eyes, or lungs) (moderate), and Contamination. The use-restrictions concern is moderate. The score is a hazard score on EWG's own scale; it is not a regulatory status.

Where is this read from?

More ingredient files: Hydroquinone · Dibutyl phthalate · Diethylhexyl phthalate · all 66 ingredient files

Method: California's section 108980 and the EU's annexes were read in Chrome on 23 October 2026; EU lookups are by CAS number (51229-78-8) across Annexes II, III, V and VI; EWG's page was kept only if its name matched exactly; the PubChem link is the compound the CAS number resolves to. Statutes change and EWG revises pages, nothing here is a safety verdict, and an ingredient that is not on a list is not endorsed.