Ingredient profile
METHYLCHLOROISOTHIA-ZOLINONE
Raters disagreepreservativeCAS 26172-55-4
At least one of our safety lists speaks to this ingredient. Also written as methylchloroisothia zolinone, Methylchloroisothia zolinone, METHYLCHLOROISOTHIA ZOLINONE…
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
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, usually paired with methylisothiazolinone. (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
- EU Harmonised Classification (CLP Annex VI)
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
No listing foundNot on the lists we hold for this jurisdiction. That is an absence of a listing, not a safety finding.
Checked: EU Cosmetics Regulation Annexes II, III, V and VI; CLP Annex VI harmonised classification; ECHA SVHC Candidate List (cosmetics-relevant subset).
Canada
RestrictedAllowed only under stated conditions or limits.
- Health Canada · Health Canada Cosmetic Ingredient HotlistA potent sensitizer permitted only in combination with MI, in rinse-off products at a strict cap.
California
No listing foundNot on the lists we hold for this jurisdiction. That is an absence of a listing, not a safety finding.
Notes
- Strong contact sensitizer
- Health Canada Hotlist — restricted
