Ingredient file · Restricted

Is methylisothiazolinone banned or restricted in cosmetics?

Q: What does EWG Skin Deep say about methylisothiazolinone?

EWG Skin Deep scores methylisothiazolinone 7 out of 10 with good data, and lists use restrictions as high. Read 23 October 2026.

Restricted, not banned: the EU permits methylisothiazolinone within limits (Annex V, entry 39; Annex V, entry 57), the lowest cap printed being 0.0015% and the highest 0.0015%, depending on the product. 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, methylisothiazolinone is restricted by the EU (Annex V) and not listed in California; EWG Skin Deep scores it 7 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 methylisothiazolinone banned in cosmetics?

Restricted, not banned: the EU permits methylisothiazolinone within limits (Annex V, entry 39; Annex V, entry 57), the lowest cap printed being 0.0015% and the highest 0.0015%, depending on the product. California does not list it. FDA's named list does not include it. EWG Skin Deep scores it 7 out of 10 (data: good).

Methylisothiazolinone: 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 methylisothiazolinone. The EWG row marks its score; a bar shows a range.

What are the EU limits for methylisothiazolinone?

The EU does not ban methylisothiazolinone; it caps it by product type. The caps below are the annex cells as printed on the EUR-Lex consolidated text of 1 May 2026, with the decimal comma written as a point.

Methylisothiazolinone: EU capspercent; consolidated 1 May 2026

Each bar is one figure printed in an annex entry (#321 means entry 321); where an entry prints several, the table below shows which product type each applies to.

Methylisothiazolinone in the EU Cosmetics Regulation, found by CAS number 2682-20-4
Where	Annex	Cap, threshold and product type	Condition
Annex V, entry 39 as printed: Mixture of 5-Chloro-2-methyl-isothiazol-3(2H)-one and 2-methylisothiazol-3(2H)-one	Permitted preservatives	0.0015 % (of a mixture in the ratio 3:1 of 5-chloro-2-methylisothiazol 3(2H)-one and 2-methylisothiazol-3 (2H)-one) Rinse-off products	No condition printed in the entry.
Annex V, entry 57 as printed: 2-Methyl-2H-isothiazol-3-one	Permitted preservatives	0.0015 % Rinse-off products	No condition printed in the entry.

Is methylisothiazolinone on California's banned list?

No. It is on neither list (a), in force since 1 January 2025, nor list (b), in force from 1 January 2027, of California's Health and Safety Code section 108980.

What does EWG Skin Deep say about methylisothiazolinone?

EWG’s page gives methylisothiazolinone a hazard score of 7 out of 10 with good data. Its concerns line reads, in part: Use restrictions (high), Neurotoxicity (low), Ecotoxicology (low), and Irritation (skin, eyes, or lungs) (moderate). The use-restrictions concern is high. 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: Kojic acid · Resorcinol · p-Phenylenediamine · 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 (2682-20-4) 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.