Ingredient profile
Quaternium-91
hair conditioning
Catalogued by CosIng (a real cosmetic ingredient with a CAS number); none of our lists flag it. Also written as QUATERNIUM-91, quaternium-91.
Where each list lands
Funding shown- Safe
Greenlens Ingredient Scan
Independent
No EU-regulated hazard recognized for this ingredient.
- Safe
Greenlens Precautionary Screen
Independent
No listed hazard trait recognized for this ingredient.
- Safe
Greenlens Tolerance Screen
Independent
No prohibited or high-risk classification for this ingredient.
Also screened — not on these lists
- Health Canada Ingredient Hotlist
- California Proposition 65
- US NTP Report on Carcinogens
- IARC Monographs
- ANSES Endocrine Disruptors
- EU Microplastics Restriction
- EU Harmonised Classification (CLP Annex VI)
