Methylchloroisothiazolinone is a preservative used in cosmetics and personal care products to prevent the growth of bacteria, yeasts, and molds. It is often used in combination with methylisothiazolinone. This ingredient helps to ensure product safety and extend shelf life by inhibiting microbial contamination.
NonePreservativeVeganEvidence: High
BenefitNone 0 / 4
RiskSerious 3.5 / 4
Sensitization
Irritation
Rated by SpottyLabs' ingredient methodology, independent of brands.
Things to watch
Can cause skin sensitization and allergic reactions
High risk of contact dermatitis
Spot questionable ingredients in seconds
SpottyLabs scans any skincare product and rates every ingredient for benefit, risk and safety. Free and independent — no brand is paying us.
App coming soon
Products with Methylchloroisothiazolinone
Original Root Stimulator Olive Oil Moisturizing Hair Lotion
What is Methylchloroisothiazolinone used for in cosmetics?
Methylchloroisothiazolinone is used as a preservative in cosmetics and personal care products. Its primary function is to prevent the growth of harmful microorganisms like bacteria and fungi, ensuring the product remains safe and effective for its intended shelf life.
Is Methylchloroisothiazolinone safe for sensitive skin?
Methylchloroisothiazolinone is a known sensitizer and can cause allergic reactions, especially in individuals with sensitive skin or a history of eczema. Due to its high potential for sensitization, its use in leave-on products is restricted or prohibited in many regions.
Spotty Labs