Caredermis

Methylisothiazolinone

Severity 8/10

preservative · also known as mit, mi

Is Methylisothiazolinone safe?

Methylisothiazolinone carries significant published concerns (allergy risk, irritation).

In plain language

A preservative behind one of the largest contact-allergy epidemics in cosmetic history. The EU banned it from leave-on products and restricts it in rinse-off products to 15 ppm.

A Caredermis plain-language explanation to help you read the label — not a regulator statement. The sourced facts are the classifications and status shown on this page.

Documented concerns

Each concern below is drawn from official data — see the cited sources ↓

Allergy risk

8/10

Caused an epidemic of contact allergy; banned in EU leave-on products.

Irritation

5/10

Irritating even in people without allergy.

Official regulatory status

Pulled directly from official regulatory datasets and expert reviews — not our own judgement.

EU-permitted preservative (max 0,0015 % Rinse-off products)CIR: safe as used (with qualifications)

EU SCCS safety opinions

  • · Opinion on Methylisothiazolinone
Read SCCS opinions ↗

Guidance by skin profile

Caredermis editorial guidance based on the concerns above — checked against the official records on every build, but not itself a regulator statement.

  • Sensitive skinBest avoided
  • Oily & acne-proneNo specific concern
  • Dry skinNo specific concern
  • PregnancyUse with caution
  • Babies & kidsBest avoided
  • Eczema-proneBest avoided

Sources

Each authority below is shown only because our ingested copy of its data lists Methylisothiazolinone — not because we asserted it. Follow a link to verify the classification or regulation directly.

CIR conclusion from the Cosmetic Ingredient Review (CIR) Quick Reference Table — cir-safety.org (snapshot in data/sources/)(point-in-time snapshot; CIR's live record may have been updated since).

See our methodology for how these map to concern levels. Informational only — not medical advice.

Products in our library containing Methylisothiazolinone

Related ingredients

Ingredients with a similar role or shared type of concern — useful for comparing what's on your label.

Checking a specific product? Paste its full ingredient list and we'll analyze everything at once.