Methylchloroisothiazolinone/Methylisothiazolinone

This patient information on Methylchloroisothiazolinone/Methylisothiazolinone is provided by John L. Meisenheimer, M.D. a board certified Dermatologist and skin care specialist based in Orlando, Florida. This information is not intended as a substitute for the medical advice or treatment of a dermatologist or other physician.

The results from your patch testing showed a positive reaction (contact allergy) to Methylchloroisothiazoline/Methylisothiazolinone. Your immune system reacts with its defense mechanisms with each exposure of Methylchloroisothiazoline/ Methylisothiazolinone to your skin. It is unknown why certain individuals develop allergic sensitivities. In some it may take repeat exposures over long periods of time before an allergy develops. Once you have become sensitized (allergic) your immune system always “remembers” and you will be Methylchloroisothiazoline/Methylisothiazolinone sensitive. If you currently have eczema this chemical may be the cause but other factors may play a role as well. The information below will help you avoid this allergen.

This chemical mix is used as preservative found in cosmetics, shampoos and skin care products.

It also has several uses in industry.

Where is chemical found?

Adhesives
Air conditioners
Baby wipes
Bronzers
Bubble bath
Cleansers
Concealers
Creams
Cutting fluids
Detergents
Eye shadows
Fabric softeners
Glues
Hair conditioners
Jet fuels
Latex paint emulsions
Lotions
Makeup foundations
Makeup remover
Mascara
Medications
Metal working fluids
Moisturizers
Pesticides
Polishes
Powders
Printing ink
Radiography
Self-tanners
Shampoo
Slim control agent in paper mills
Soap
Sunscreens
Toilet papers
Water cooling paints

Hints on avoiding chemical:

Choose products listed only on your personalized contact allergen database, which has been provided to you. Products listed on your contact allergen resource database will be free of Methylchloroisothiazolinone/Methylisothiazolinone and safe to use.
Please be aware that if your spouse or significant other uses topical skin care products that contain this chemical skin-to-skin transfer may occur to you.
It may take 2 to 3 weeks of avoiding exposure before improvement of your eruption begins.

Other names you may see Methylchlorosothiazolone/methylisothiazolone listed as:

2-Methyl-4-isothiazolin-3-one.
5-Chloro-2-methyl-4-isothiazolin-3-one.
Acticide
Algucid
Amerstat 250
Euxyl K 100
Fennosan IT 21
Grotan TK2
Kathon
Kathon CG
Mergal K7
Metatin GT
Methylchloroisothiazolinone
Methylisothiazolinone (MI)
Mitco CC 32 L

Possible occupational Exposures:

Hairdressers and Cosmetologists
Janitors
Machine Operators
Metalworkers