What is Methylisothiazolinone's role in skincare products?

Methylisothiazolinone functions as a preservative in skincare products, preventing the proliferation of bacteria, yeasts, and molds. This helps to maintain the product's integrity and safety throughout its use.

Why is Methylisothiazolinone a concern for some people?

Methylisothiazolinone is a significant concern for some individuals because it is a potent sensitizer, meaning it can cause allergic contact dermatitis. Regulatory bodies have restricted its use and concentration in cosmetic products due to the high incidence of allergic reactions.

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Methylisothiazolinone

Methylisothiazolinone is a preservative commonly found in water-based cosmetics and personal care products. It effectively prevents the growth of bacteria and fungi, thereby extending product shelf life and ensuring consumer safety. However, it is a known sensitizer, especially at higher concentrations.

PreservativeVegan

BenefitNone 0 / 4

RiskSerious 3.5 / 4

Sensitization i4 / 4

Risk of allergic contact dermatitis or immune-based reactions. Fragrance allergens, preservatives, botanicals, and some dyes may score here.

Irritation i3 / 4

Risk of short-term irritation — stinging, burning, dryness, redness, or discomfort. Common for strong actives, acids, retinoids, fragrances, and harsh surfactants.

Rated by SpottyLabs' ingredient methodology, independent of brands.

Things to watch

Can cause skin sensitization and allergic reactions
High risk of contact dermatitis

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Products with Methylisothiazolinone

Ieva

Nutritive Conditioner

3.2/ 54/4/8

Herbal Essences

White Strawberry & Mint Clean Shampoo

Body Wash for Men, 24/7 Shower Clean

2.1/ 50/8/8

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Frequently asked questions

What is Methylisothiazolinone's role in skincare products?: Methylisothiazolinone functions as a preservative in skincare products, preventing the proliferation of bacteria, yeasts, and molds. This helps to maintain the product's integrity and safety throughout its use.
Why is Methylisothiazolinone a concern for some people?: Methylisothiazolinone is a significant concern for some individuals because it is a potent sensitizer, meaning it can cause allergic contact dermatitis. Regulatory bodies have restricted its use and concentration in cosmetic products due to the high incidence of allergic reactions.