Kathon® is a chemical compound, a mixture of two heterocyclic isothiazolinones: methylchloroisothiazolinone and methylisothiazolinone included in the formulation in approximate proportions of 3:1 and with magnesium chloride and magnesium nitrate as stabilisers. It is a registered trademark of Rohm and Haas Company.
Name breakdown and function of the components
- Kathon - A trade name referring to a mix of two isothiazolinones, specifically methylchloroisothiazolinone (MCI) and methylisothiazolinone (MI). These compounds are primarily used as preservatives.
Isothiazolinones, and specifically the Kathon mix, are employed as biocides in a range of products, including personal care items, due to their effective antimicrobial properties.
Description and function of the raw materials used in production
- Isothiazolinones - Chemical compounds that have the ability to inhibit microbial growth and hence are used as preservatives.
Summary of the industrial production process step by step
- Chemical Synthesis - Isothiazolinones are produced through a series of chemical reactions.
- Formulation - The isothiazolinones are then combined in specific proportions to create the Kathon mix.
- Purification - The resulting mix might be purified to ensure removal of impurities.
- Packaging - Finally, the Kathon mix is packaged for distribution and use in end products.
It appears as a colourless transparent liquid.

What it is used for and where
It is a highly efficient, broad-spectrum, non-oxidising antibacterial, stable at acid pH and in more oxidising environments. It is commercially available under different names: Kathon 886, Kathon CG, Kathon LX and others.
Cosmetics
Preservative. Any product containing organic, inorganic compounds, water, needs to be preserved from microbial contamination. Preservatives act against the development of harmful microorganisms and against oxidation of the product.
Food
Chemical preservative that prevents the degradation of milk samples and maintains the authenticity of analysis results.
Safety
Studies published so far attribute contact allergies, contact dermatitis (1) and, if inhaled, risk of eosinophilia-mediated disease in the lung to Kathon (2)
Commercial applications
Cosmetic products: Used as a preservative in many cosmetic products such as creams, lotions, shampoos, and bath gels.
Cleaning products: It's also utilized in cleansers, soaps, and other cleaning products to stave off microbial growth.
Industrial products: Found in certain paints, adhesives, and other industrial products as a preservative.
Properties
Preservative: Helps prevent the growth of bacteria, fungi, and other microorganisms in products.
Biocidal: Possesses biocidal properties that kill microorganisms.
Compendium of the most significant studies with reference to properties, intake, effects.
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- Molecular Formula C8H9ClN2O2S2 C4H4ClNOS
- Molecular Weight 264.8
- CAS 55965-84-9 (Kathon 886), 5-chloro-2- methyl-4-isothiazolin-3-one (methylchloroisothiazolinone) 26172-55-4, 2-methyl-4 isothiazolin-3-one (methylisothiazolinone) 2682-20-4
- UNII 15O9QS218W
- EC Number 911-418-6 611-341-5 932-593-5 247-500-7



