Preservatives
Methylisothiazolinone (MI)
Restricted in European Union, United Kingdom, Canada and Japan; its status in Nigeria is not confirmed.
Why it matters
A strong contact allergen. EU scientists found no safe level in leave-on products after allergy cases rose.
What to look for on the label
Methylisothiazolinone, methylchloroisothiazolinone, MI, MCI.
Full name: Methylisothiazolinone (MI) / MCI-MI
Country by country
Around the worldRestricted in European Union, United Kingdom, Canada and Japan; its status in Nigeria is not confirmed.
Why: A strong contact allergen. EU scientists found no safe level in leave-on products after allergy cases rose.
| Place | Status |
|---|---|
| Nigeria | not confirmed |
| European Union | restrictedRinse-off only, max 0.0015% (MI: Reg 2017/1224; MCI/MI: Reg 1003/2014). Banned in leave-on. |
| United Kingdom | restrictedMI (V/57) and MCI/MI (V/39): rinse-off only, max 0.0015%. |
| United States | no specific ruleNot on FDA prohibited/restricted ingredients list. |
| Canada | restrictedBanned in leave-on. Rinse-off max 0.0015%, MI plus MCI/MI combined. |
| Japan | restrictedMI max 0.01%, not on mucosa. MCI/MI rinse-off only. |
More about Methylisothiazolinone (MI)
Sources: EU Reg 2017/1224 (Publications Office) · legislation.gov.uk UK Annex V (revised) · FDA Prohibited & Restricted Ingredients · Health Canada Hotlist change log · MHLW Standards for Cosmetics (English). Checked 2026-10-19; rules change, so check the regulator before relying on it.
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Education, not legal advice. Rules change: check with your country's regulator before relying on this.