Quick Search
Methylchloroisothiazolinone is a powerful synthetic preservative that belongs to the isothiazolinone family of compounds, which are widely recognized for their strong antimicrobial activity against a broad spectrum of bacteria, fungi, and yeasts.
Methylchloroisothiazolinone’s primary function is to inhibit microbial growth and prevent spoilage, making it an essential ingredient in a wide variety of consumer and industrial products.
The dual nature of Methylchloroisothiazolinone—being both an indispensable preservative and a potential allergen—has made it a subject of intense regulatory scrutiny and ongoing scientific evaluation.
CAS Number: 26172-55-4
EC Number: 247-500-7
Molecular Formula: C4H5NOS.C4H4ClNOS
Molecular Weight: 264.75
Synonyms: Methylchloroisothiazolinone, MCI, CMI, Kathon CG (when mixed with MI), 5-Chloro-2-methyl-4-isothiazolin-3-one, 5-Chloro-2-methyl-1,2-thiazol-3(2H)-one, 5-Chloro-N-methylisothiazolin-3-one, 5-Chloro-2-methyl-4-isothiazolin-3-ol (variant), 3(2H)-Isothiazolone, 5-chloro-2-methyl-, Chloromethylisothiazolinone, 5-Chloro-2-methylisothiazol-3(2H)-one, 5-Chloro-2-methylisothiazolin-3-one, Isothiazolone, 5-chloro-2-methyl-, 5-Chloro-2-methyl-2H-isothiazol-3-one, 2-Methyl-4-isothiazolin-3-one, 5-chloro derivative, 5-Chloro-2-methylisothiazol-3-one, 5-Chloro-2-methyl-3(2H)-isothiazolone, 5-Chloro-2-methyl-4-isothiazolin-3-one (IUPAC variant), 5-Chloro-2-methyl-3-isothiazolone, 2-Methyl-5-chloro-3-isothiazolone, CMI/MI mixture (common preservative blend), Kathon 886, Kathon WT, Kathon LX, Kathon CG-ICP, Kathon MW, Kathon WTA, Kathon LXE, Kathon 893, Kathon 886 MW, Kathon 893 MW, Kathon CG II, Kathon PFM, Kathon WT CS, Kathon CG SB, Kathon FP 1.5, Kathon MW 1.5, Kathon LXE 1.5, Euxyl K 100 (trade name, mixture with MI), Euxyl K 101, Acticide MBS, Acticide CMG, Acticide MBS 50, Grotan OX, Grotan OX 20, Rocima 200, Preventol CMK, Proxel CMI, Dowicide CMI, Rholpex CM
Methylchloroisothiazolinone is a synthetic preservative belonging to the isothiazolinone family, widely used for its strong antimicrobial and antifungal properties.
Methylchloroisothiazolinone typically appears as a clear to pale-yellow liquid and is often formulated in combination with methylisothiazolinone (MI) to enhance stability and efficacy.
Methylchloroisothiazolinone is commonly employed in personal care products such as shampoos, lotions, and cleansers, as well as in household cleaners, paints, adhesives, and industrial fluids, where it prevents microbial spoilage and extends shelf life.
However, due to its potent sensitizing potential, Methylchloroisothiazolinone has been associated with allergic contact dermatitis and is subject to strict regulatory controls, particularly in cosmetic applications where its concentration is limited to ensure consumer safety.
Methylchloroisothiazolinone's dual role as both an effective preservative and a regulated allergen makes it a significant compound in modern product formulations.
Methylchloroisothiazolinone is the organic compound with the formula S(C2HCl)C(O)N(CH3).
Methylchloroisothiazolinone is a white solid that melts near room temperature.
The compound is an isothiazolinone, a class of heterocycles used as biocides.
These compounds have an active sulphur moiety that is able to oxidize thiol-containing residues, thereby effectively killing most aerobic and anaerobic bacteria.
Methylchloroisothiazolinone is often used in combination with methylisothiazolinone, a mixture known as Kathon.
The isothiazolinones have attracted attention because they can cause contact dermatitis.
Methylchloroisothiazolinone is effective against gram-positive and gram-negative bacteria, yeast, and fungi.
In combination with methylisothiazolinone, it goes by the trade name Kathon CG (among others).
Introduced into cosmetics in the mid-1970s, Methylchloroisothiazolinone elicited a great number of sensitizations in consumers.
This led to Methylchloroisothiazolinone not being included in cosmetics other than rinse-off products.
When combined with methylisothiazolinone, methylchloroisothiazolinone offers preservative benefit.
This blend is used in many products instead of parabens, despite the fact that parabens have a better safety track record and lower incidence of causing a sensitising reaction.
Methylchloroisothiazolinone belongs to the isothiazolinone group of compounds.
Methylchloroisothiazolinone comes as a clear, colorless liquid with a mild odor.
Methylchloroisothiazolinone contains sulfur foam in its formulation.
Methylisothiazolinone and Methylchloroisothiazolinone may be hard to pronounce, but they can be even harder on the body.
These common preservatives are found in many liquid personal care products.
Methylchloroisothiazolinone acts as a preservative in cosmetic products.
Methylchloroisothiazolinone helps prevent the growth and proliferation of microorganisms within the product, extending the product's shelf life.
Kathon 886 metalwork fluid is a mixture of the two isothiazoliones contained in Kathon CG, at a 13.9% concentration.
Methylchloroisothiazolinone is mainly contained in metalwork fluids.
As an active component of Aigezid Ⅱ and contained in a water bath used for phtotographic development, Methylchloroisothiazolinone caused contact dermatitis in a photograph developer.
Methylchloroisothiazolinone/methylisothiazolinone mixture is a mixture of isothiazolinone-derived biocides.
Methylchloroisothiazolinone is effective against Gram-positive and Gram-negative bacteria with MIC values of 0.0002, 0.0002, 0.00005, and 0.00005% (w/w) for S. aureus, P. aeruginosa, A. niger, and C. albicans, respectively.
Methylchloroisothiazolinone can elicit contact sensitization.
Formulations containing Methylchloroisothiazolinone have been used for controlling microbial growth in industrial and household products.
Methylchloroisothiazolinone is a chemical used in skin care products, household cleaners, and industrial products as a preservative.
Methylchloroisothiazolinone is usually mixed with methylisothiazolinone and the combination is sometimes called Kathon CG or Euxyl K 100.
Methylchloroisothiazolinone was first used in Europe in the 1970s and the United States in the 1980s.
The original European recommendation was to use 0.003% concentration or 30 parts per million (ppm).
This led to many allergic reactions.
The recommendation then changed to 15 ppm in wash-off products and 7.5 ppm in leave-on cosmetics.
In 2000, companies started using methylisothiazolinone in industrial products.
By 2005 some cosmetic companies were using as much as 50 to 100 ppm.
There were reports of more reactions to methylchloroisothiazolinone, methylisothiazolinone, and the combination of the two.
Some countries like Canada don’t allow methylchloroisothiazolinone as a single ingredient.
Methylchloroisothiazolinone must be combined with methylisothiazolinone and can only be used in rinse-off products at a concentration of 15 ppm.
Methylchloroisothiazolinone is an isothiazolinone commonly used as a preservative with antibacterial and antifungal properties.
Methylchloroisothiazolinone is found within many commercially available cosmetics, lotions, and makeup removers.
Methylchloroisothiazolinone is also a known dermatological sensitizer and allergen; some of its side effects include flaky or scaly skin, breakouts, redness or itchiness, and moderate to severe swelling in the eye area.
The American Contact Dermatitis Society named Methylchloroisothiazolinone the Contact Allergen of the Year for 2013.
Methylchloroisothiazolinone is a powerful synthetic preservative that belongs to the isothiazolinone family of compounds, which are widely recognized for their strong antimicrobial activity against a broad spectrum of bacteria, fungi, and yeasts.
Chemically, Methylchloroisothiazolinone is a chlorinated derivative of methylisothiazolinone (MI), and the two substances are often used together in formulations because their combination, known as Kathon CG, provides enhanced stability, synergistic antimicrobial effects, and longer-lasting preservation.
Methylchloroisothiazolinone typically appears as a clear to pale-yellow liquid and is highly soluble in water, which makes it particularly suitable for aqueous-based formulations.
Methylchloroisothiazolinone's primary function is to inhibit microbial growth and prevent spoilage, making it an essential ingredient in a wide variety of consumer and industrial products.
In the cosmetics and personal care industry, Methylchloroisothiazolinone has historically been included in shampoos, conditioners, lotions, liquid soaps, and facial cleansers to ensure product safety and prolong shelf life.
Beyond cosmetics, Methylchloroisothiazolinone is also widely employed in household cleaning agents, detergents, paints, adhesives, cooling systems, paper coatings, and metalworking fluids, where microbial contamination could otherwise lead to product degradation, foul odors, or compromised performance.
Despite Methylchloroisothiazolinone's effectiveness as a preservative also known to be a strong skin sensitizer and has been associated with allergic contact dermatitis, particularly when used in leave-on cosmetic products or at higher concentrations.
Because of these risks, regulatory authorities such as the European Union and the U.S. Food and Drug Administration have set strict limits on its allowable concentration.
The dual nature of Methylchloroisothiazolinone—being both an indispensable preservative and a potential allergen—has made it a subject of intense regulatory scrutiny and ongoing scientific evaluation.
While Methylchloroisothiazolinone continues to play a vital role in industrial and household applications where stringent microbial control is required, its use in personal care products is carefully monitored and restricted to balance consumer safety with the benefits of product preservation.
This complex profile makes methylchloroisothiazolinone a significant compound in modern chemistry, representative of the broader challenges in formulating safe, stable, and effective products in today’s consumer and industrial markets.
Market Overview of Methylchloroisothiazolinone:
The global market for Methylchloroisothiazolinone is experiencing steady growth, driven by its widespread use as a powerful preservative in cosmetics, personal care products, household cleaners, paints, adhesives, and industrial fluids.
Market estimates vary, with projections ranging from approximately USD 120–390 million in 2024 to as high as USD 600 million by 2032–2033, reflecting a compound annual growth rate (CAGR) of 4–8% depending on the source.
The Asia-Pacific region is emerging as the fastest-growing market due to rapid industrialization and expanding consumer demand, while North America and Europe represent more mature markets with moderate, steady growth.
Demand is largely fueled by the need for effective antimicrobial protection and longer shelf life in both consumer and industrial products.
Applications of Methylchloroisothiazolinone:
Methylchloroisothiazolinone is found in many water-based personal care products and cosmetics.
Methylchloroisothiazolinone was first used in cosmetics in the 1970s.
Methylchloroisothiazolinone is also used in glue production, detergents, paints, fuels, and other industrial processes.
Methylchloroisothiazolinone is known by the registered tradename Kathon CG when used in combination with methylisothiazolinone.
Methylchloroisothiazolinone may be used in combination with other preservatives including ethylparaben, benzalkonium chloride, bronopol and phenoxyethanol.
Uses of Methylchloroisothiazolinone:
Methylchloroisothiazolinone is a synthetic preservative that is widely used because it possesses strong antimicrobial and antifungal properties.
In cosmetics and personal care products, Methylchloroisothiazolinone is incorporated into shampoos, conditioners, body washes, lotions, and soaps to prevent microbial contamination and extend shelf life.
In these formulations, manufacturers often combine Methylchloroisothiazolinone with methylisothiazolinone (MI) as Kathon CG to enhance preservation efficacy.
In household and cleaning products, Methylchloroisothiazolinone is added to detergents, dishwashing liquids, and multipurpose cleaners to inhibit bacterial and fungal growth.
In industrial applications, industries use Methylchloroisothiazolinone in paints, adhesives, coatings, and inks to prevent spoilage and degradation, while engineers employ it in metalworking fluids, cooling systems, and cutting oils to control microbial growth.
In materials processing, the chemical industry applies Methylchloroisothiazolinone to paper, leather, and textiles to protect against mold and decay.
In water treatment and construction, operators and manufacturers use Methylchloroisothiazolinone in industrial water systems, plasters, and grouts to safeguard against microbial fouling.
Overall, Methylchloroisothiazolinone serves as a versatile preservative that prolongs product stability and safety across multiple sectors, although regulators strictly control its concentration in cosmetics due to its allergenic potential.
Methylchloroisothiazolinone has been used as a preservative for years, making it beneficial in two forms.
Methylchloroisothiazolinone acts as a preservative for the cosmetic product in which it is used.
Cosmetic products composed of water are prone to microbial growth during use and storage.
This microbial growth can spoil the product and also cause harmful effects to the user.
Sometimes, a product can come into contact with microbes naturally present on the user's skin during use.
Microbial growth can cause discoloration and reduce the quality of the product.
Methylchloroisothiazolinone prevents the growth of microbes and ensures product quality and safety.
Methylchloroisothiazolinone is also useful for minimizing skin exposure to harmful microbes.
Methylchloroisothiazolinone is primarily used in rinse-off formulations such as shampoos, bath products, skin care, and hair care products.
Methylchloroisothiazolinone is valued for its broad-spectrum antimicrobial and antifungal properties, making it a versatile preservative across consumer, cosmetic, and industrial sectors.
Methylchloroisothiazolinone’s primary uses include:
Cosmetics and Personal Care Products:
Methylchloroisothiazolinone is incorporated in shampoos, conditioners, body washes, facial cleansers, hand soaps, and lotions to prevent microbial contamination and extend shelf life.
Manufacturers commonly formulate Methylchloroisothiazolinone with methylisothiazolinone (MI) as Kathon CG, which enhances preservation efficacy.
Regulators restrict Methylchloroisothiazolinone to low concentrations in rinse-off products due to sensitization risks, and the EU bans it in leave-on cosmetics.
Household and Cleaning Products:
Methylchloroisothiazolinone is added to detergents, dishwashing liquids, multipurpose cleaners, and disinfectants to inhibit bacterial and fungal growth during storage.
Industrial and Material Preservation:
Industries use Methylchloroisothiazolinone in paints, adhesives, sealants, coatings, and inks to prevent microbial spoilage that can cause odor, viscosity changes, or product degradation.
Engineers employ Methylchloroisothiazolinone in metalworking fluids, cutting oils, and cooling systems where water-based formulations are highly susceptible to microbial contamination.
The chemical industry applies Methylchloroisothiazolinone in paper, leather, and textile processing for preservation and protection against mold and decay.
Water Treatment and Specialty Applications:
Water treatment operators sometimes use Methylchloroisothiazolinone in industrial water systems as a biocide to control microbial fouling.
The construction industry uses Methylchloroisothiazolinone in plasters and grouts to safeguard against mold growth.
In essence, Methylchloroisothiazolinone’s key value lies in its ability to prolong product stability and safety by controlling microbial growth, making it indispensable in many sectors—despite regulatory restrictions in cosmetics due to its allergenic potential.
Benefits of Methylchloroisothiazolinone:
Methylchloroisothiazolinone offers several important benefits that make it valuable across diverse industries.
Methylchloroisothiazolinone provides broad-spectrum antimicrobial and antifungal protection, which helps products resist contamination from bacteria, yeast, and mold.
Manufacturers benefit from Methylchloroisothiazolinone's effectiveness at very low concentrations, which reduces formulation costs while still ensuring long-lasting preservation.
Industries value Methylchloroisothiazolinone's compatibility with a wide range of water-based formulations, including cosmetics, cleaners, paints, adhesives, and coatings, which makes it highly versatile.
Product developers use Methylchloroisothiazolinone to extend the shelf life and stability of consumer goods, preventing spoilage, odor formation, and quality degradation.
Regulators recognize that, when used at controlled levels, Methylchloroisothiazolinone ensures product safety and reduces the need for more aggressive or higher-dose preservatives.
Overall, Methylchloroisothiazolinone enables companies to maintain product quality, reduce waste, and meet consumer expectations for safe and reliable goods.
Production of Methylchloroisothiazolinone:
Methylchloroisothiazolinone is produced through controlled chemical synthesis involving the reaction of methylisothiazolinone (MI) with chlorine or chlorinating agents under specific conditions.
Chemical manufacturers typically carry out the process in aqueous solutions, where MI serves as the starting compound and the chlorination step introduces the chloro-substituent to form Methylchloroisothiazolinone.
Industrial chemists carefully monitor reaction parameters such as pH, temperature, and chlorine dosage to ensure high purity and to minimize unwanted by-products.
Producers often formulate Methylchloroisothiazolinone directly with methylisothiazolinone (resulting in the commercial mixture Kathon CG), since this combination provides synergistic antimicrobial activity and greater stability.
After synthesis, manufacturers subject Methylchloroisothiazolinone solutions to quality control testing to verify concentration, antimicrobial efficacy, and compliance with safety standards.
Overall, the production process is designed to yield a highly effective preservative while maintaining strict safety and environmental controls.
Synthesis of Methylchloroisothiazolinone:
Methylchloroisothiazolinone is synthesized through the chlorination of methylisothiazolinone (MI), which serves as the key precursor.
Chemical manufacturers begin by preparing MI from the reaction of appropriate precursors such as methylamine derivatives with sulfur and other intermediates that construct the isothiazolinone ring.
Once MI is obtained, industrial chemists introduce a controlled chlorination step, in which chlorine or chlorinating agents react with MI to produce the chloro-substituted compound Methylchloroisothiazolinone.
Process engineers carefully regulate parameters such as reaction time, temperature, and pH to maximize yield and minimize the formation of unwanted by-products.
Manufacturers often stabilize the resulting Methylchloroisothiazolinone by formulating it in aqueous solution together with MI, creating the commercial preservative blend known as Kathon CG.
Overall, the synthesis emphasizes efficiency, purity, and stability, ensuring that the final compound exhibits strong antimicrobial performance while meeting regulatory quality standards.
History of Methylchloroisothiazolinone:
Methylchloroisothiazolinone was first introduced in the 1970s as part of the isothiazolinone family of preservatives, developed to provide strong antimicrobial protection in water-based formulations.
Chemical companies initially marketed Methylchloroisothiazolinone in combination with methylisothiazolinone (MI) under the trade name Kathon CG, which quickly became popular in cosmetics, personal care, and household products because of its broad-spectrum efficacy at very low concentrations.
During the 1980s and 1990s, manufacturers expanded the use of Methylchloroisothiazolinone into industrial applications, including paints, adhesives, coatings, and metalworking fluids, where microbial contamination caused major performance issues.
However, by the 2000s, regulators began to raise concerns about allergic contact dermatitis linked to Methylchloroisothiazolinone, particularly in leave-on cosmetics.
In 2015, the European Union banned the use of Methylchloroisothiazolinone in leave-on products and restricted its use to very low levels in rinse-off formulations.
Despite these regulatory changes, Methylchloroisothiazolinone continues to play an important role as a preservative in industrial products and carefully controlled consumer formulations, illustrating its long-standing significance in preservation chemistry.
Handling and Storage of Methylchloroisothiazolinone:
Handle Methylchloroisothiazolinone in well-ventilated areas, avoiding inhalation of vapors, mists, or aerosols.
Use appropriate personal protective equipment (PPE), including chemical-resistant gloves, protective goggles, and suitable clothing.
Do not eat, drink, or smoke while handling the product.
Store in tightly sealed containers made of plastic or lined steel in a cool, dry, and well-ventilated environment.
Protect from direct sunlight, extreme heat, and moisture.
Keep away from incompatible substances such as strong oxidizing agents, bases, and reducing agents.
Stability and Reactivity of Methylchloroisothiazolinone:
Chemical stability:
Stable under normal storage and recommended handling conditions.
Reactivity:
Reacts with strong oxidizers and bases; may degrade under extreme pH conditions.
Conditions to avoid:
Excessive heat, direct sunlight, strong acids or alkalis, and prolonged exposure to air or moisture.
Hazardous decomposition products:
May release toxic fumes such as nitrogen oxides (NOₓ), sulfur oxides (SOₓ), and carbon oxides (CO, CO₂) during thermal decomposition.
Incompatibility:
Avoid contact with alkaline materials, oxidizing agents, and reactive metals.
First Aid Measures of Methylchloroisothiazolinone:
Inhalation:
Move the affected person to fresh air.
If breathing is difficult, provide oxygen and seek medical attention immediately.
Skin contact:
Wash thoroughly with soap and plenty of water.
Remove contaminated clothing.
Seek medical advice if irritation or allergic reaction develops.
Eye contact:
Rinse cautiously with water for at least 15 minutes, holding eyelids open.
Seek prompt medical attention.
Ingestion:
Rinse mouth with water (do not induce vomiting).
Give small amounts of water to drink if the person is conscious.
Seek immediate medical attention.
Firefighting Measures of Methylchloroisothiazolinone:
Suitable extinguishing media:
Use water spray, foam, dry chemical, or carbon dioxide (CO₂).
Unsuitable extinguishing media:
High-pressure water jets may spread the material.
Hazards from combustion:
Thermal decomposition may release toxic and irritating fumes (nitrogen oxides, sulfur oxides, carbon oxides).
Protective equipment for firefighters:
Wear self-contained breathing apparatus (SCBA) and full protective clothing.
Accidental Release Measures of Methylchloroisothiazolinone:
Personal precautions:
Wear PPE (gloves, goggles, protective clothing).
Avoid inhalation and direct contact with skin or eyes.
Environmental precautions:
Prevent entry into drains, soil, or natural waterways, as the substance can cause long-term aquatic hazards.
Methods for cleaning up:
Contain and absorb spillage with inert materials (sand, earth, vermiculite).
Collect in properly labeled containers for disposal according to local regulations.
Clean the contaminated area with water and detergent.
Exposure Controls / Personal Protection of Methylchloroisothiazolinone:
Engineering controls:
Provide adequate ventilation; local exhaust ventilation is recommended for confined areas.
Respiratory protection:
Use approved respirators if exposure limits are exceeded or if ventilation is inadequate.
Hand protection:
Wear chemical-resistant gloves (nitrile or neoprene recommended).
Eye protection:
Use safety goggles or a face shield.
Skin/body protection:
Wear a protective lab coat, apron, long sleeves, and closed footwear.
Hygiene measures:
Wash hands, face, and exposed skin thoroughly after handling.
Do not eat, drink, or smoke in work areas.
Identifiers of Methylchloroisothiazolinone:
CAS Number: 26172-55-4
Beilstein Reference: 1210149
ChEBI: CHEBI:53621
ChemSpider: 30800
DrugBank: DB14197
ECHA InfoCard: 100.043.167
EC Number: 247-500-7
PubChem CID: 33344
UNII: DEL7T5QRPN
CompTox Dashboard (EPA): DTXSID9034286
InChI: InChI=1S/C4H4ClNOS/c1-6-4(7)2-3(5)8-6/h2H,1H3
Key: DHNRXBZYEKSXIM-UHFFFAOYSA-N
InChI=1/C4H4ClNOS/c1-6-4(7)2-3(5)8-6/h2H,1H3
Key: DHNRXBZYEKSXIM-UHFFFAOYAV
SMILES: ClC=1SN(C(=O)C=1)C
CAS No.: 55965-84-9
CBNumber: CB62130868
Molecular Formula: C4H5NOS.C4H4ClNOS
Molecular Weight: 264.75
MDL Number: MFCD01716911
Chemical name: Methylchloroisothiazolinone
Common abbreviation: MCI
Other names: 5-Chloro-2-methyl-4-isothiazolin-3-one; Kathon CG (when mixed with MI)
CAS number: 26172-55-4
EC number (EINECS): 247-500-7
UN number: Not classified as a dangerous good under UN transport regulations
Molecular formula: C₄H₄ClNOS
Molecular weight: 149.60 g/mol
IUPAC name: 5-chloro-2-methyl-1,2-thiazol-3(2H)-one
Chemical family: Isothiazolinones (heterocyclic compounds with sulfur and nitrogen)
Appearance: Clear to pale-yellow liquid (usually in aqueous solution with MI)
Odor: Mild to none
Properties of Methylchloroisothiazolinone:
Chemical Name: Methylchloroisothiazolinone
Abbreviation: MCI
CAS Number: 26172-55-4
EC Number (EINECS/ELINCS): 247-500-7
PubChem CID: 2493
UNII (FDA Unique Ingredient Identifier): N13H9EOA7I
RTECS Number: GR8925000
InChI: InChI=1S/C4H4ClNOS/c1-2-3(6)7-4(5)8-2/h1H3,(H,6,7)
InChI Key: XPYNDGWNZFHOPB-UHFFFAOYSA-N
SMILES: CC1=NC(=O)SN1Cl
Molecular Formula: C₄H₄ClNOS
Molecular Weight: 149.60 g/mol
Chemical Family: Isothiazolinones (heterocyclic nitrogen–sulfur compounds)
Appearance: Clear to pale-yellow liquid (typically supplied as aqueous solution)
Odor: Faint to none
Stability: Stable under recommended storage; decomposes with heat or strong oxidizers
Chemical name: Methylchloroisothiazolinone
Molecular formula: C₄H₄ClNOS
Molecular weight: 149.60 g/mol
Appearance: Clear to pale-yellow liquid (usually supplied as aqueous solution with MI)
Odor: Faint or none
Physical state: Liquid (often in stabilized solution, e.g., Kathon CG)
Density (at 20 °C): ~1.27 g/cm³
pH (1% solution): 4.0 – 5.0 (slightly acidic)
Melting point: Not well-defined (decomposes before melting)
Boiling point: Decomposes on heating, no true boiling point
Solubility:
Water: Miscible
Alcohols: Soluble (e.g., ethanol, isopropanol)
Nonpolar solvents: Low solubility
Partition coefficient (log Kow): ~0.7 (low potential for bioaccumulation)
Vapor pressure (25 °C): Very low (<1 × 10⁻⁵ Pa)
Flash point: Not flammable in aqueous formulations
Chemical formula: C4H4ClNOS
Molar mass: 149.59 g·mol−1
Appearance: white solid
Density: 1.02 g/cm3
Melting point: 52 °C (126 °F; 325 K)
Solubility in water: Miscible
Boiling point: 100.1℃ at 101.325kPa
Density: d20 1.19
vapor pressure: 0.003-17Pa at 20-45℃
storage temp.: Sealed in dry,Room Temperature
solubility: Chloroform (Soluble), DMSO (Slightly), Methanol (Slightly), Water
form: Liquid
color: Colorless to light yellow
PH: 3.43 at 20℃ and 10g/L
InChI: InChI=1S/C4H4ClNOS.C4H5NOS/c1-6-4(7)2-3(5)8-6;1-5-4(6)2-3-7-5/h2H,1H3;2-3H,1H3
InChIKey: QYYMDNHUJFIDDQ-UHFFFAOYSA-N
SMILES: O=C1C=C(SN1C)Cl.O=C1C=CSN1C
LogP: -0.34-0.81 at 10-30℃ and pH5-9
Surface tension: 72.6-73mN/m at 1-1.106g/L and 19.5-20℃
Dissociation constant: 2.81-4.2 at 20-25℃
Names of Methylchloroisothiazolinone:
Preferred IUPAC name:
5-Chloro-2-methyl-1,2-thiazol-3(2H)-one
Other names:
5-Chloro-2-methylisothiazol-3(2H)-one
5-Chloro-2-methyl-4-isothiazolin-3-one
Chloromethylisothiazolinone
Chloromethylisothiazolone
Methylchloroisothiazolinone
Methylchloroisothiazolone
CMI
CMIT
MCI
MCIT
CIT
