Methylisothiazolinone — answers to MIT
Appears in 3 scanned products.
A synthetic preservative used to stop bacteria and fungi from growing in water-based cosmetic products.
Why it’s used
Effective at very low concentrations against a broad range of microbes, making it popular in shampoos, lotions, and wipes.
What the evidence says
The SCCS concluded that MIT is a potent skin sensitizer, and rates of contact allergy linked to it rose sharply as its use increased through the 2010s. This led to tightened EU restrictions, including a ban in leave-on products and lowered limits in rinse-off ones.
Context
Risk is strongly tied to leave-on use; rinse-off products carry substantially lower risk because contact time is short. Current EU rules reflect this distinction directly.
Educational information, not medical or safety advice. Consult a professional for allergies or medical concerns.