Very Disliked
Methylchloroisothiazolinone
Preservative
Preservative
May cause Irritation
These ingredients have higher irritation potential, particularly for sensitive skin. Common reactions include redness, burning, or itching. If you have sensitive skin, patch test first and introduce these ingredients slowly into your routine.
Can worsen Eczema
These ingredients are known to be potential triggers for eczema. However, triggers vary greatly between individuals. Keep a diary to identify your personal triggers and work with a dermatologist to develop a gentle, effective routine.
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 926 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
