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Methylisothiazolinone is abbreviated as MIT or MI.
Methylisothiazolinone is an organic compound with the formula S(CH) 2C (O) NCH3.
Methylisothiazolinone is a white solid.
Methylisothiazolinone is used as a biocide in personal care product and other industrial applications.

CAS number: 2682-20-4
molecular formula: C4H5NOS
molecular weight: 115.2
EINECS number: 220-239-6

Methylisothiazolinone is a clear, colorless liquid that is soluble in water.
Methylisothiazolinone increases the safety and shelf life of products by preventing the growth of bacteria and yeast.
Without preservatives such as methylisothiazolinone, products may begin to smell unpleasant and change color.
Or molds that can produce toxins that are harmful to health may form.

Methylisothiazolinone is a widely used preservative in the personal care industry.
Methylisothiazolinone and Methylchloroisothiazolinone are preservatives commonly used in liquid cosmetics and personal care products.
Both chemicals alone prevent bacterial growth in cosmetic products.
However, they are most commonly used as a mixture in products.

Methylisothiazolinone is used to control microbial growth in solutions containing water.
Methylisothiazolinone is typically used in a formulation containing 5-chloro-2-methyl-4-isothiazolin-3-one (CMIT) in a 3:1 mixture (CMIT:MIT) sold commercially as 'Kathon'.
Kathon is available to manufacturers as a concentrated stock solution containing 1.5% to 15% CMIT/MIT.
Methylisothiazolinone is also used to control slime in the production of food contact paper products.
Additionally, this product acts as an antimicrobial agent in latex adhesives and paper coatings that come into contact with food.

Methylisothiazolinone is found in numerous products, including those that claim to be “natural.”
In addition to cleaning products, detergents, lotions, sunscreens, shampoos, hair conditioners, hair dye and body wash products, the list includes;
There are baby products such as mascara, shaving cream, make-up remover, liquid soaps and wipes, lotions and shampoos.

Methylisothiazolinone (MI) is a super effective preservative against bacteria at surprisingly low concentrations.
The problem, however, is that it can sensitize and irritate the skin quite easily when used in leave-in formulas.

Methylisothiazolinone is allergenic and cytotoxic.
This has led to some concerns about its use.
A report was published by the European Scientific Committee on Cosmetic and Non-Food Products for Consumers (SCCNFP) in 2003.
MIT concluded that not enough information was available to allow for adequate risk assessment analysis.

As a result of increasing reports of consumer impact;
Methylisothiazolinone has led to new research, including a report published in 2014 by the European Commission Scientific Committee on Consumer Safety.

The report result is as follows:

" Detected by diagnostic patch tests.
Thereupon, the dramatic increase in the reported rates of contact allergy cases to Methylisothiazolinone is unprecedented in Europe.
There have been repeated warnings about the increase.
The main reason for the increase is the increased consumer exposure to MI from cosmetic products.
Exposure to Methylisothiazolinone in household products, paints, and in the occupational environment also needs to be considered.
The delay in re-evaluating the safety of Methylisothiazolinone in cosmetic products is of concern to the SCCS.
"Methylisothiazolinone has negatively affected consumer safety."

Methylisothiazolinone (MIT) and Methylchloroisothiazolinone (CMIT) may be difficult to pronounce, but they can be even more challenging on the body.
MIT has been associated with allergic reactions, lung toxicity, and neurotoxicity.
The European SCCS has declared that no safe concentration of MIT exists in released products.
Methylisothiazolinones use in cosmetics is banned in Canada.

Health problems commonly linked to MIT include:
skin reactions (it is a contact allergen), skin sensitization, painful rashes, inhalation toxicity, organ toxicity, neurotoxicity.

Chemical: MIT

Physical Form: solid
Melting Point: 50–51°C (experience)
Boiling Point: 93°C, 4 Pa ​​(exp.)
Steam Pressure: 8.26 Pa (experience)
Water Solubility: 959 g/L (calculated)
Can it ionize in the environment?: no
log K: -0.49 (experience)

Methylisothiazolinone is a biocide widely used, along with other isothiazolinones, as a preservative in personal care products.
Methylisothiazolinone is also used in many industrial processes such as paint and paper production, metal processing, mining and sanitation.
Because methylisothiazolinone is a potent cytotoxin, its use has come under fire due to the dangers it poses to humans and the environment.
Methylisothiazolinone creates problems especially when added to products such as lotions that remain on the skin.

In recent years, the European Union has begun to crack down on potentially dangerous preservatives in cosmetics.
In particular, the combination of methylisothiazolinone and methylchloroisothiazolinone was restricted earlier this year.
The use of methylisothiazolinone alone was planned to be banned in 2017.
The EU's sweeping restrictions have severely reduced the number of preservatives allowed in personal care products.
Banning animal testing in cosmetic products eliminates the possibility of new biocides being found in the near future.

-Methylisothiazolinone chemical and physical structure:

Appearance: dark brown
Melting point: 48.0 – 49.5 °C
Boiling point : /
Density: 1.35 g/ml at 25 °C
Rel. vap. dens. :
Steam Press. : 2 x 10-2 torr at 25 °C
Daily Power: -0.486
pH at 25 °C: 2.58

Methylisothiazolinone is a cosmetic preservative.
The main uses for methylisothiazolinone are leave-in products such as hand and body lotions.
Methylisothiazolinone is volatile.

Methylisothiazolinone has a molecular weight of 115.2 Da and a density of 1.02 g/mL at 25 °C.
The peak wavelengths of the ultraviolet/visible spectrum of the product, trade name Methylisothiazolinone, are at 274 nm for a neutral solution.
at 266 nm for an acidic solution and 274 nm for a basic solution.

Methylisothiazolinone is produced by the controlled chlorination of dimethyl dithiodipropionamide in solvent.
Methylisothiazolinone is then neutralized.
Once extracted into water, a strip of solvent is applied.
Methylisothiazolinone is among the isothion components.
Isothiazolinones are used as biocides due to their pronounced antibacterial and antifungal activities over a wide range of pH values.
Isothinants are heterocyclic organic compounds.
Methylisothiazolinone is used as a preservative in a ratio of 3:1.
Methylisothiazolinone is less effective than MCI/MI and therefore needs to be used in higher concentrations to be sufficiently biocidal.
The only difference in the molecular structure of these substances is the presence of a chloride in MCI, which leads to different types of interactions with allergenic proteins.
The emergence of a highly electrophilic and therefore very reactive intermediate makes MCI more allergenic.

Methylisothiazolinone can be found in industrial environments, in coolants and oils.
In recent years, there has been a transition from solvent-based paints to water-based paints, which are more environmentally friendly.
As a result, it became necessary to protect the paint with MCI/MI and later with Methylisothiazolinone, the most commonly used preservatives.
The risk of sensitivity to paint affects not only painters and paint factory workers, but also home users.


Preservatives contribute greatly to consumer health by protecting cosmetic products against microbial spoilage.
Preservatives are especially needed in cosmetic formulations containing water.
Because microorganisms can colonize and multiply in an aqueous (water-containing) environment.
Cosmetics often contain more than one preservative, and these preservative systems act simultaneously against different bacteria, yeasts or molds.
Each of these substances has been extensively tested and evaluated for safety.
To ensure optimum shelf life and safe application, manufacturers always use only the lowest possible effective concentration in a product.
Methylisothiazolinone is used as a preservative in cosmetic rinses at concentrations up to 15 ppm
Preservative usually recommended for use in rinse-only products such as cleansers or shampoos.
Methylisothiazolinone is known to be a sensitizer when used in leave-on products.
Methylisothiazolinone is used in both rinse-off and rinse-off cosmetic products.

Methylisothiazolinone is limited to low amounts to prevent sensitization while maintaining its effectiveness as a preservative.
Methylisothiazolinone has raised questions about even greater than the low allowable amount (0.01%).
Methylisothiazolinone is more sensitive than most other preservatives.
Methylisothiazolinone does not have many specific benefits for your hair.
Methylisothiazolinone may make hair shinier, but not thicker or stronger.
Methylisothiazolinone is used strictly in cosmetics as a preservative and antibacterial.

Conditions to which the methylisothiazolinone product is exposed, such as storage in a warehouse.
Hot and humid environments, such as a shower stall, are things to consider.
Preservatives such as methylisothiazolinone keep our hair care products safe to use for longer periods of time.

Although methylisothiazolinonine does not directly benefit hair, it has many benefits in product formulation.
Methylisothiazolinone protects products at very low usage levels.
Methylisothiazolinone is also water soluble, very easy to mix.
At the same time, Methylisothiazolinone is stable over a wide pH range, making it suitable for many types of formulas such as shampoos and conditioners.

Methylisothiazolinone can be used by all hair types.
Methylisothiazolinone is more important to be conscious about your possible allergies or skin before using products containing the methylisothiazolinone ingredient.
They are often used in water-based formulations rather than oil- or wax-based products.
Methylisothiazolinone has a bit of a bad reputation in the beauty industry because it is considered a standardized chemical allergen.
This means it is associated with allergic reactions.

Preservatives are important for every formulation as they ensure the safety and quality of the product.
However, Methylisothiazolinone is particularly important in water-based formulations.
This is because water-based formulations are more susceptible to degradation and microbial growth.
For example, contamination of your product may occur through use, even when you take the product out with your hands or leave the lid of the product open for a while.

When a product spoils due to microbial growth, it can cause discoloration, unpleasant odors, or impaired texture and consistency.
However, apart from the sensory properties of the product, degradation can also increase the risk of infection or irritate the skin.

While Methylisothiazolinone is sometimes used alone in formulations, it is often combined with Methylchloroisothiazolinone.
Historically, Methylisothiazolinone and Methylchloroisothiazolinone were used in both rinse-off and leave-on products.
Rinsing products include cleanser, soap, shampoo, etc. These products are designed to be rinsed off the skin after a short time.
Leave-on products include moisturizer, lotion, make-up, etc. products and are designed to be left on the skin.
As you can imagine, they have different levels of interaction with the skin due to the different amount of time they spend on it.
This difference can determine security and sensitivity.

In North America, Methylisothiazolinone is used, theoretically disguised in the term 'fragrance' or 'perfume'.
Because it is one of the chemicals allowed in any mixture that can be described as such.
The full list of compounds allowed in fragrance can be seen here.
Choosing products that use only natural fragrances is an almost absolute guarantee of safety.
Remember that scents themselves can trigger allergies.

Cosmetic companies defend their use of this ingredient by stating that they use it in very low amounts, around 15 ppm.
They also claim that because the ingredients are in "rinsed off" products, any dangerous or toxic effects are wasted.
Meanwhile, you have a long-lasting, bacteria-free formula on your shelf.

Organ System Toxicity: Exposure to high concentrations of Methylisothiazolinone (above 50%) increases moist body weight.
Methylisothiazolinone presents with a range of symptoms, including death.
Autopsies revealed that death occurred due to reddening of the lungs and distension of the intestines.
This may be concerning for factory workers exposed to high concentrations of Methylisothiazolinone.
Currently, there are no National Institute for Occupational Safety and Health (NIOSH) guidelines for limiting Methylisothiazolinone exposure in the workplace.

Allergies: Methylisothiazolinone (MIT) and Methylchloroisothiazolinone (CMIT) are two of the most predominant contact allergens found in cosmetic products.
In a clinical study, researchers find that dermal irritation occurs most commonly with products containing MIT/CMIT mixtures.
But he found that it wasn't as common in products containing only Methylisothiazolinone.
The American Contact Dermatitis Association named MIT Allergen of the Year in 2013 for skin sensitivity resulting from dermal exposure.

There is controversy about the concentrations of MIT/CMIT that trigger an allergic reaction.
Methylisothiazolinone harmful effects have been found to range from 7.5 to 100 parts per million.

Neurotoxicity: In vitro cell studies on Methylisothiazolinone (MIT) showed signs of neurotoxicity when exposed to liquid Methylisothiazolinone.
However, animal studies have found no significant signs of neurotoxicity when rodents are exposed to Methylisothiazolinone via drinking water.


3(2H)-Isothiazolone, 2-methyl-
2682-20-4 (freebase)
Caswell No. 572A
Microcare MT
Kordek MLX
EINECS 220-239-6
MIT (biocide)
Acticide M 10
Acticide M 20
Bestcide 600
Kordek 50
Kordek 50C
Kordek 573F
Kathon CG 243
Neolone 950; 2-Methyl-4-isothiazolin-3-one; 2-Methylisothiazol-3-one
HSDB 8200
MIT 950
MT 10
NW 838
2-Methyl-4-isothiazolin-3-one (MI)
Methylisothiazolinone free base
2-Methyl-3(2H)-isothiazolone #
2-Methyl-4-isothiazolin-3-one, 95%
2-Methyl-4-isothiazolin-3-one, analytical standard
2-Methyl-4-isothiazolin-3-one 100 microg/mL in Acetonitrile

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