Explore Routine Login


Our database includes 469 products that contain Methylisothiazolinone.

You should know




MI is a preservative and known skin irritant. In the past, MI was used for its ability to prevent bacteria, yeast, and fungi growth in low doses.

Nowadays, you'll most likely see MI combined with Methylchloroisothiazolinone (MCI). Trade names for this combination include Kathon CG or Euxyl K 100.

Since then, numerous studies have shown this ingredient to cause contact dermatitis, or skin irritation.

The use of this ingredient varies around the world:

  • The EU has banned this ingredient for leave-on products and it is capped at 0.0015% for rinse-off products.
  • The US allows this ingredient in concentrations of up to 15 parts per million (ppm) in rinse-off products and 8 ppm in other products.
  • Canada allows this ingredient to be used with MCI in rinse-off products. The combination must not exceed 0.0015%.

Also known as: Euxyl K 100, Mi, 5-Chloro-2-Methyl-4-Isothiazolin-3-One, Mc/Mci-Cg, Mc/Mci-886, Kathon , and 5-Chloro-20methyl-3[H2]-Isothiazolinone

Methylisothiazolinone is a rare cosmetic ingredient, with about 0.9% of the products in our database containing it.

What it does:


Community Stats

164 people from our community have liked or disliked this ingredient.

Users who dislike it 💔

Often have the following skin types:

Sensitive Dry

Usually have one or more of the following skin concerns:

Sensitivity • Fine Lines • Dryness • Wrinkles

Where it's used

Methylisothiazolinone is most often found as ingredient number 22 within an ingredient list.

These are the categories of products that use Methylisothiazolinone the most:

CosIng Data

  • CosIng ID: 35341
  • EC #:  220-239-6
  • All Functions: Preservative
What is CosIng?

CosIng is the European Commission database for information on cosmetic substances and ingredients.

SkinSort uses CosIng to source some of it's data on ingredient names and functions.