Ingredient profile
METHYL ISOTHIAZOLINONE
Raters disagreepreservativeCAS 2682-20-4
At least one of our safety lists speaks to this ingredient. Also written as methyl isothiazolinone, Methyl-isothiazolinone, Methyl Isothiazolinone…
Raters don't agree. Here's where each one stands
Safe
Greenlens Ingredient Scan
Independent
Greenlens Tolerance Screen
Independent
Caution
Greenlens Precautionary Screen
Independent
Health Canada Ingredient Hotlist
Government
EU Harmonised Classification (CLP Annex VI)
Government
Concern
—
Where each list lands
Funding shown- Safe
Greenlens Ingredient Scan
Independent
No EU-regulated hazard recognized for this ingredient.
- Caution
Greenlens Precautionary Screen
Independent
A preservative and potent contact sensitizer (a past "allergen of the year"). (ChemSec SIN List (Substitute It Now))
- Safe
Greenlens Tolerance Screen
Also screened — not on these lists
- California Proposition 65
- US NTP Report on Carcinogens
- IARC Monographs
- ANSES Endocrine Disruptors
- EU Microplastics Restriction
Where regulators stand
Shown side by side, never combinedEach jurisdiction is reported on its own terms, from its own official lists. Where they disagree, that disagreement is the finding. Absence from a list is never a safety claim.
European Union
FlaggedCarries a formal hazard classification. Not itself a cosmetic use rule.
- ECHA (EU CLP Regulation) · EU CLP Regulation Annex VI, Table 3 (harmonised classification, ECHA export): Skin Sens. 1ACarries an EU harmonised classification (Skin Sens. 1A) — a skin sensitiser under CLP Annex VI, index 613-326-00-9. A hazard classification, not proof of harm at the level used.
Canada
RestrictedAllowed only under stated conditions or limits.
- Health Canada · Health Canada Cosmetic Ingredient HotlistA potent sensitizer: not permitted in leave-on products; capped in rinse-off products.
Notes
- Strong contact sensitizer
- EU harmonised skin sensitizer
- Health Canada Hotlist — restricted
