Why is methylisothiazolinone banned in some products?

The EU banned methylisothiazolinone from leave-on cosmetics after a rise in contact allergy.

Evidence

Source:: SCCS/1521/13; EU Regulation 2017/1224
Applies to:: Formulations containing methylisothiazolinone
What this does not establish:: How a given product performs on your skin. Finished-product pH and concentration are rarely published, so this describes the chemistry, not a measurement of any specific product.
Last reviewed:: 2026-09-26

In practice

Methylisothiazolinone caused a well-documented rise in contact allergy through the 2010s, which led the EU to ban it from leave-on cosmetics and restrict it in rinse-off products. Seeing it here is worth noting if you have a history of preservative reactions.

Dermasift analyses skincare formulations against published cosmetic science. This is information, not medical advice — for a diagnosed skin condition, speak to a dermatologist.

Check this against a product’s ingredient list

Why is methylisothiazolinone banned in some products?

The EU banned methylisothiazolinone from leave-on cosmetics after a rise in contact allergy.

Evidence

Source:: SCCS/1521/13; EU Regulation 2017/1224
Applies to:: Formulations containing methylisothiazolinone
What this does not establish:: How a given product performs on your skin. Finished-product pH and concentration are rarely published, so this describes the chemistry, not a measurement of any specific product.
Last reviewed:: 2026-09-26

In practice

Dermasift analyses skincare formulations against published cosmetic science. This is information, not medical advice — for a diagnosed skin condition, speak to a dermatologist.

Check this against a product’s ingredient list