What is it?

“Methylchloroisothiazolinone (5-chloro-2-methyl-4-isothiazolin-3-one),  also referred to as MCI, is a preservative with antibacterial and antifungal effects within the group of isothiazolinones. Chemical formula C4H4ClNOS” Wikipedia

What are the effects?

This ingredient belongs to the group:

The Swedish Society for Nature Conservation (SSNC) list methylchloroisothiazolinone as a substance causing allergies.

The mixture of methylisothiazolinone and methylchloroisothiazolinone in the same product restricted in Canada. The total concentration of the two substances in one product is not allowed to exceed 0.0015%.

How is it used?

Methylchloroisothiazolinone is numerously used as a preservative in water-based cosmetic products*. The substance is found in products such as lotions, makeup and shampoo to prevent bacterial, fungal and yeast growth.

We use the European Commissions definition of Cosmetics:
“Cosmetics range from everyday hygiene products such as soap, shampoo, deodorant, and toothpaste to luxury beauty items including perfumes and makeup”.

Read about the other ingredients.


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