DMDM hydantoin

Also known as: 1,3-dimethylol-5,5-dimethylhydantoin, formaldehyde releaser

Moderate concernunder our published method

By NordicScan Evidence Engine · generated from structured evidence records · source spans verified by automated gates · Reviewed 2026-07-08 · Evidence snapshot geo-wave1-evidence-snapshot-2026-07-08 · Scoring engine det_v3 · how we score.

What it is

DMDM hydantoin is a preservative used in some shampoos, conditioners, lotions and personal-care products.

Why people ask

People ask because it belongs to the formaldehyde-releaser preservative family, where EU labelling rules changed.

What our method flags — by use

Cosmetic · EU

In EU cosmetics, our method rates DMDM hydantoin as moderate-concern because formaldehyde-releaser products can trigger a required warning above the EU threshold.

The EU restricted by Regulation (EU) 2022/1181 finished cosmetic products that release formaldehyde to carry the warning "releases formaldehyde" above 0.001% released formaldehyde.

Authority / source	Finding (our paraphrase)	Evidence tier	Date	Link
European Union / EUR-Lex	The EU restricted by Regulation (EU) 2022/1181 finished cosmetic products that release formaldehyde to carry the warning "releases formaldehyde" above 0.001% released formaldehyde.	authority_regulatory	2022-07-08	source
European Union / EUR-Lex	The EU flagged by Regulation (EU) 2022/1181 finished products containing formaldehyde releasers for the warning "releases formaldehyde" above 0.001% released formaldehyde.	authority_regulatory / --	2022-07-08	source

Evidence coverage for this use: Fair (computed from source count × authority tier × recency; signals depth, does not change the concern band).

How this moves a product’s score

On a product score, DMDM hydantoin contributes a moderate concern signal from the EU formaldehyde-releaser warning regime.

Nordic Scan provides ingredient information and a concern score under our published method, for general consumer research. It is not medical advice and not a medical device, and does not diagnose, treat, cure, or prevent any disease, or determine the safety of any product. Decide for yourself.

Common questions

Is DMDM hydantoin treated as a cosmetic preservative family signal?: Yes. The source cell is the EU formaldehyde-releaser warning rule, so the page keeps the claim scoped to that family.

This is what DMDM hydantoin is. What’s in the products you buy? Scan a label and see the concern signals our method flags. Get the app.

Reviewed 2026-07-08 · Evidence snapshot geo-wave1-evidence-snapshot-2026-07-08 · Scoring engine det_v3 · Sources checked 2026-07-08 · See how we score.