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Methylisothiazolinone (MIT)

* A preservative

* Please read TIA's articles on Preservatives and Are They Safe and Why Products Need Preservatives


Methylisothiazolinone, or MIT as it is sometimes known, is a preservative used in cosmetics and beauty products. It is a powerful biocide, or "chemical substance capable of killing living organisms, usually in a selective way." Biocides are a general term that includes antimicrobial, germicide, antibiotic, and antifungal. Ultimately, Methylisothiazolinone is used to prevent a wide variety of bacteria and fungi from growing in cosmetics and beauty products, most often in shampoo. It is only approved for use in rinse-off formulas and at low concentrations.

Although many connections are made between Methylisothiazolinone and Alzheimer's disease and other conditions, research by and shows that the concentration levels found in cosmetics and beauty products are so low that there is no risk in using products with this preservative.

Safety Measures/Side Effects:

One study at the University of Pittsburgh found Methylisothiazolinone to be a neurotoxin, but in that study, the neurotoxicity occurred after direct exposure caused a chain reaction involving zinc levels and DNA enzymes to destroy rat brain cells in culture samples. Despite this evidence, the Cosmetic, Toiletries and Fragrance Association deemed Methylisothiazolinone safe for use in cosmetic formulas (Wikipedia).

The EWG lists Methylisothiazolinone as a sensitizer and irritant. It is approved for use in rinse-off products by the CIR.

Recommended Products w/ Methylisothiazolinone (MIT):

Ouidad Water Works Shampoo, Christophe Robin Crème Lavante au Citron for Color Treated HairPevonia Botanica’s SpaTeen, Be Fine Exfoliating Cleanser, Philip B African Shea Butter Shampoo

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