Haute Custom Beauty is 100% Methylisothiazolinone Free

This preservative is often used in rinse-off products such as shampoos or cleansers as well as on leave-on products. This ingredient is proven to be sensitizing and a problematic allergen. The American Contact Dermatitis Society named Methylisothiazolinone its 2013 Allergen of the Year. Methylisothiazolinone should also be avoided with non-sensitive skin as people can develop allergies or irritation.