Methylisothiazolinone, commonly abbreviated as MI or MIT, is a specialty cosmetic ingredient belonging to the isothiazolinone family of preservatives. It is identified by the INCI name METHYLISOTHIAZOLINONE, CAS Number 2682-20-4, and EC Number 220-239-6. Its chemical name is 2-Methyl-2H-isothiazol-3-one, and it is a synthetic ingredient primarily associated with preservative functionality in cosmetic formulations.
Methylisothiazolinone is used to help protect susceptible cosmetic products from microbial spoilage, particularly formulations containing water. COSMILE Europe identifies Methylisothiazolinone as a preservative and notes its occurrence in various rinse-off cosmetic products.
For companies searching for a Methylisothiazolinone cosmetic ingredient manufacturer in India, the product should be evaluated according to its chemical identity, concentration, analytical specification, formulation suitability, documentation and the regulatory requirements of the destination market.
Methylisothiazolinone is a small heterocyclic compound containing sulfur and nitrogen. It is commonly identified chemically as 2-Methyl-4-isothiazolin-3-one or 2-Methyl-2,3-dihydroisothiazol-3-one. The principal CAS Number is 2682-20-4, while the EC Number is 220-239-6.
Methylisothiazolinone is generally encountered commercially either as a concentrated ingredient or as part of preservative systems. The exact physical form, concentration and specification depend on the commercial grade. For B2B procurement, manufacturers should confirm the active concentration, appearance, analytical method, impurity profile, packaging and batch-specific Certificate of Analysis before production use.
It is particularly important to distinguish pure Methylisothiazolinone from mixtures containing Methylisothiazolinone and Methylchloroisothiazolinone (MCI/CMIT), because these are separate regulatory entries and have different compositional requirements.
The primary function of Methylisothiazolinone is preservation. It helps protect cosmetic formulations against microbial deterioration and is therefore relevant to products where microbial control is required. COSMILE Europe lists METHYLISOTHIAZOLINONE as a preservative and describes its use in rinse-off products.
Methylisothiazolinone has been widely used in cosmetic preservation systems, but its use requires careful regulatory and formulation assessment because the substance has recognized sensitising potential. COSMILE Europe notes that current EU restrictions allow its use only in rinse-off cosmetic products and at a low permitted concentration.
Under the current EU Annex V framework, Methylisothiazolinone alone is permitted in rinse-off products at a maximum concentration of 0.0015% (15 ppm). It is not permitted as a preservative in leave-on cosmetic products.
This concentration is a finished-cosmetic regulatory limit, not the assay or purity specification of the raw material.
Methylisothiazolinone is primarily associated with rinse-off cosmetic and personal-care products. COSMILE Europe specifically identifies its occurrence in various rinse-off products and also notes that it may be encountered in combination with Methylchloroisothiazolinone.
Potential product categories include selected shampoos, conditioners, cleansing products, shower products and other rinse-off formulations, subject to the regulations applicable to the finished product.
For cosmetic manufacturers sourcing Methylisothiazolinone cosmetic ingredient in India, the distinction between pure Methylisothiazolinone and MCI/MI preservative mixtures is important. EU regulations separately identify Methylisothiazolinone alone and the 3:1 MCI/MI mixture, with separate concentration conditions.
The final application and use level should always be established according to the target-market legislation and the validated preservation strategy of the finished formulation.
Methylisothiazolinone should be evaluated carefully during formulation because preservation effectiveness depends on the complete formulation system. Factors including product type, pH, water phase, processing conditions, packaging, compatibility with other ingredients and total preservative system should be considered during development.
The concentration of Methylisothiazolinone in the finished product is particularly important. In the EU, the current permitted level for Methylisothiazolinone alone is 15 ppm in rinse-off products.
Formulators should also ensure that Methylisothiazolinone is not unintentionally combined with a separate MCI/MI preservative system in a manner inconsistent with the applicable regulatory requirements. EU legislation specifically states that the entries for Methylisothiazolinone alone and the MCI/MI mixture are mutually exclusive.
Quality control should be based on the actual commercial specification and validated analytical method. An assay value should only be entered into the CMS Assay (HPLC) field when the supplied SDP grade is actually tested using an approved HPLC method.
Businesses searching for a Methylisothiazolinone cosmetic ingredient manufacturer in India should evaluate the raw material based on chemical identity, concentration, purity, analytical method, physical characteristics, packaging and batch-specific documentation.
A Methylisothiazolinone cosmetic ingredient supplier in India should provide suitable technical information such as Certificate of Analysis, Safety Data Sheet and product specifications. For Methylisothiazolinone manufacturing in India, consistency of the commercial grade is important for manufacturers developing controlled rinse-off cosmetic formulations.
Companies looking for a Methylisothiazolinone bulk cosmetic ingredient supplier in India should define the required grade, concentration, packaging and documentation before procurement. Destination-market regulations should also be checked because permitted applications and concentration limits vary by jurisdiction.
Swapnroop can position Methylisothiazolinone as a specialty cosmetic preservative ingredient for B2B technical evaluation and sourcing requirements. Buyers can evaluate the ingredient according to its identity, concentration, quality specification, formulation suitability and intended application.
For businesses searching for a Methylisothiazolinone cosmetic ingredient manufacturer and supplier in India, the material can be assessed according to product-specific technical requirements, documentation, packaging and bulk supply needs. Final cosmetic use should be determined according to the current regulations of the intended market and the approved specification of the supplied material.
| Parameter | Specification |
|---|---|
| Appearance | White or colourless crystals / white powder |