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Home/Ingredient Guide/Methylchloroisothiazolinone (MCI)
Ingredient guide

Methylchloroisothiazolinone (MCI).

Also known as: MCI, CMIT, 5-chloro-2-methyl-4-isothiazolin-3-one, Kathon CG (MCI/MI blend)

A potent synthetic biocide and preservative, almost always used in combination with methylisothiazolinone (MI) as the blend 'Kathon CG.

Regulations

Global status.

How methylchloroisothiazolinone (mci) is regulated in cosmetics around the world.

Restricted in 9Allowed in 1No data for 1

90% of countries with data ban or restrict this ingredient

🇺🇸USA
Allowed
🇪🇺EU
Restricted
Details

Permitted only in rinse-off at max 0.0015% as 3:1 MCI/MI mixture; banned in leave-on since 2016.

🇬🇧UK
Restricted
Details

Mirrors EU; rinse-off only at max 0.0015%.

🇨🇦Canada
Restricted
Details

Rinse-off only at max 0.0015% as MCI/MI mixture.

🇯🇵Japan
Restricted
Details

Permitted with limits under MHLW positive list.

🇰🇷S. Korea
Restricted
Details

Banned in leave-on; max 0.0015% in rinse-off.

🇦🇺Australia
Restricted
Details

Restricted; concentration limits apply.

🇨🇳China
Restricted
Details

Rinse-off only at max 0.0015% per Safety Technical Standards.

🇧🇷Brazil
Restricted
Details

ANVISA: rinse-off only at max 0.0015%.

🇮🇳India
No Data
🌏ASEAN
Restricted
Details

Rinse-off only at max 0.0015%, aligned with EU.

Why it’s used

The reason brands include it.

Extremely effective broad-spectrum preservative at very low concentrations. The MCI/MI blend (Kathon CG) is one of the most cost-effective preservation systems available.

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products in our database

0

brands use it

1

product categories

Categories

Methylchloroisothiazolinone (MCI) in product types.

Click a category to see every product containing methylchloroisothiazolinone (mci).

Alternatives

Common alternatives.

potassium sorbate
sodium benzoate
ethylhexylglycerin
tocopherol (vitamin E)
rosemary extract

What Numbrrrz uses

Numbrrrz does not use methylchloroisothiazolinone (mci). Every tube is organic coconut oil, organic beeswax, organic jojoba oil and vitamin E, plus organic essential oils or flavoring in the scented versions.

Questions

Quick answers.

What is Methylchloroisothiazolinone (MCI)?
A potent synthetic biocide and preservative, almost always used in combination with methylisothiazolinone (MI) as the blend 'Kathon CG.
Why is Methylchloroisothiazolinone (MCI) used in cosmetics?
Extremely effective broad-spectrum preservative at very low concentrations. The MCI/MI blend (Kathon CG) is one of the most cost-effective preservation systems available.
How is Methylchloroisothiazolinone (MCI) regulated?
Still permitted in US cosmetics at any concentration. No restrictions despite being banned in EU leave-on cosmetics and heavily restricted in rinse-off products. It is not permitted in cosmetics sold in the EU. Canada restricts its use in cosmetics.
Does Numbrrrz contain Methylchloroisothiazolinone (MCI)?
No. Numbrrrz is made from four base ingredients: organic coconut oil, organic beeswax, organic jojoba oil and vitamin E, plus organic essential oils or flavoring in the scented versions. That is a formulation choice, not a judgment about other products.
Four base ingredients

Prefer a short label?

Organic coconut oil, organic beeswax, organic jojoba oil and vitamin E, in a 0.5 oz (14 g) USDA Organic tube.