What is it?
Methylisothiazolinone (MI) is a widely used preservative and biocide.

How can I avoid it?
Avoidance requires reading the product labels, package inserts, Material Safety Data Sheets (MSDS), and on occasion, direct communication with the manufacturer.

Skin contact with Methylisothiazolinone (MI) is required for it to cause a rash. Discontinuation of exposure to products containing Methylisothiazolinone (MI) should result in improvement and/or resolution of your dermatitis. By law, all products made in the US for topical use have the ingredients listed either on the product package or the box that contains it, so check the labeling of your skin care products for this ingredient. If there is no information, ask your pharmacist or call the company directly. At work, request a material safety data sheet (MSDS) to help identify potential sources of exposure.

  • Baby care - lotions, wipes, diaper cream, bubble bath, shampoo, soap
  • Industrial products
    • All purpose cleaner
    • Automatic dishwasher
    • Bath and shower cleaner
    • Bleach products
    • Building materials - adhesives, paints, resins, emulsions
    • Carpet care
    • Disinfectant
    • Fabric softener sheets
    • Fabric treatment
    • Floor care
    • Furniture polish
    • Hand dishwashing
    • Household cleaner wipes
    • Kitchen cleaners
    • Laundry detergent
    • Lice treatment
    • Metal cleaner
    • Metal working fluids
    • Oil controller
    • Oil field operations
    • Paper mills
    • Stain remover
    • Surface cleaner
    • Toilet bowl cleaner
    • Water cooling and treatment systems
    • Wood treatment
  • Skin Care Products / Cosmetics
    • Antiperspirants / Deodorants 
    • Hair sprays, gels, tonics and lotions
    • Hair Colorants / “Permanents-Relaxers”
    • Make-ups
    • Moisturizers
    • Nail Polish / Nail Polish Remover
    • Powders / Sprays
    • Shampoos / Conditioners
    • Shaving products
    • Soaps / Cleansers
    • Sunscreens and Self-Tanners
  • Spermacides
Other names for Methylisothiazolinone (MI):
  • 2-methyl- 3 (2H) -isothiazolone
  • 2-methyl-2H-isothiazol-3-one
  • 2-methyl-3 (2H) -isothiazolone
  • 2-methyl-4-isothiazolin-3-one
  • 3 (2H) -isothiazolone, 2-methyl-
  • 3 (2H) isothiazolone, 2methyl
  • 2-methyl-3 (2H) -isothiazolone
  • 2-methyl-4-isothiazolin-3-one
Potential cross-reacting/co-reacting substances:
  • Benz-isothiazolinine
  • Octyl-isothiazolinone (used in antifungals for leather processing)

How safe is it?

Hang tight. We're thinking.