Very Disliked
Methylchloroisothiazolinone
Preservative
Preservative
May cause Irritation
These ingredients are considered potential irritants, meaning they can cause irritation - but not necessarily for everyone. Everyone’s skin is different, so what bothers one person’s skin may be completely fine for someone else.
Can worsen Eczema
These are common ingredients that may trigger eczema flare-ups, but everyone’s skin is different. If you have eczema or suspect you might, it’s important to check with a medical professional for the best care and product guidance.
Explained
MCI is a preservative and known skin-irritant. It has anti-bacteria anti-fungal properties.
Studies spanning several decades have shown this ingredient to cause skin irritation and allergies.
MCI is commonly combined with methylisothiazolinone (MI). Other names for this mixture include Kathon CG and Euxyl K 100.
The use of this ingredient varies around the world:
- The EU allows this ingredient in rinse-off products up to 15 parts per million (ppm).
- The US allows this ingredient in concentrations of up to 15 ppm in both rinse-off and 7.5 ppm leave-on products.
- Canada allows this ingredient to be used with MI in rinse-off products. The combination must not exceed 0.0015%.
See all 782 products with Methylchloroisothiazolinone
Users who like it
2%
Users who avoid it
98%
What it does
Preservative
Tending to preserve or capable of preserving.
Prevalence
Less common
Percentage of products that contain it
0.9%
Top categories
Cleansers
Haircare
Masks
Position
Predominant list placement
Bottom 25%
References
Products with Methylchloroisothiazolinone
CosIng Data
CosIng ID
35333
INCI Name
METHYLCHLOROISOTHIAZOLINONE
EC #
 247-500-7
All Functions
Preservative
