Molekula
5-Chloro-2-methyl-4-isothiazolin-3-one
Supplying 4,500+ customers in over 80 countries
ISO 9001:2015 & ISO 14001:2015 certified · Supplying laboratories and industry since 1999 · Listed pack sizes are a starting point — we manufacture, source and repack to the quantity you need
5-Chloro-2-methyl-4-isothiazolin-3-one is a potent biocide used in industrial water treatment, coatings, and personal care products to prevent microbial growth. It is a halogenated isothiazolinone with the CAS number 26172-55-4, molecular formula C4H4ClNOS, and molecular weight 149.60 g/mol. Stored at 2 to 8 °C, it is classified as Danger. Molekula supplies 5-Chloro-2-methyl-4-isothiazolin-3-one from research to bulk quantities with full documentation and ISO 9001:2015 traceability.
Example image for illustration only. Other packaging and pack sizes are available.
Pricing & pack sizes
In stock — same-day dispatch
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5 g — £62.10 per pack ex VAT · £74.52 inc. VAT
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Specifications
| Property | Value |
|---|---|
| Appearance | Clear to yellow liquid - possible low melt |
| Density | (At 20°C) 1.16 to 1.32g/cm³ |
| Identification | Conforms to reference |
| pH | 2.0 - 4.0 |
| Total Active Ingredients | 14.0 - 14.5% |
| Total CIT/MIT | 2.5 - 3.4% |
| CMIT | 10.0 - 12.0% |
| MIT | 3.0 - 5.0% |
Storage & handling
| Property | Value |
|---|---|
| Storage Temperature | 2 to 8 °C |
| Transport Class | 8 (6.1) |
| Packing Group | II |
| Acidity | Acid |
Literature values
Published physical properties of the substance, not batch specifications.
| Property | Value |
|---|---|
| Melting Point | 54-55 °C |
| Vapour Pressure | 0.018 mmHg at 25 °C |
| log P (octanol/water) | 0.401 |
Source: PubChem CID 33344 (HSDB)
Identification
| Property | Value |
|---|---|
| SKU | 32309525 |
| CAS Number | 26172-55-4 |
| IUPAC Name | 5-chloro-2-methyl-1,2-thiazol-3-one |
| EC Number | 247-500-7 |
| Molecular Formula | C4H4ClNOS |
| Molecular Weight | 149.60 |
| Exact Mass | 148.9702 |
| SMILES | CN1C(=O)C=C(S1)Cl |
| InChIKey | DHNRXBZYEKSXIM-UHFFFAOYSA-N |
| InChI | InChI=1S/C4H4ClNOS/c1-6-4(7)2-3(5)8-6/h2H,1H3 |
| PubChem CID | 33344 |
| UN Number | UN2922 |
| REACH Code | Y110 |
| TSCA Listed | Yes |
| HTS Code | 2934101000 |
| Tariff Code | 2934100090 |
Safety & GHS
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Corrosive
GHS05
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Toxic
GHS06
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Hazardous to the Environment
GHS09
Hazard statements
- EUH071 Corrosive to the respiratory tract
- H302+312 Harmful if swallowed or in contact with skin
- H314 (sub cat. 1B) Causes severe skin burns and eye damage
- H317 May cause an allergic skin reaction
- H331 Toxic if inhaled
- H400 Very toxic to aquatic life
- H410 Very toxic to aquatic life with long lasting effects
Precautionary statements
- P260 Do not breathe dust/fume/gas/mist/vapours/spray
- P273 Avoid release to the environment
- P280 Wear protective gloves/protective clothing/eye protection/face protection
- P301+310 IF SWALLOWED: Immediately call a POISON CENTER or doctor/physician
- P305+351+338 IF IN EYES: Rinse with water for several minutes. Remove contact lenses if present and easy to do. Continue rinsing
- P333+313 IF skin irritation or a rash occurs: Get medical advice/attention
- P337+313 If eye irritation persists get medical advice/attention
Documents
Safety Data Sheets (SDS)
Available in English, French, German, Italian, Spanish.
Certificate of Analysis (CoA) by batch
Enter a lot or batch number to retrieve the CoA for that specific batch. We can generate one from spec data if no PDF is on file.
Quality certificates
Molekula Group is certified to ISO 9001:2015 (quality) and ISO 14001:2015 (environmental management), audited by a UKAS-accredited body. Both certificates are valid to 17 May 2028.
Synonyms
- 3(2H)-Isothiazolone, 5-chloro-2-methyl-
- 5-Chloro-2-methyl-3-isothiazolone
- 5-Chloro-2-methyl-3(2H)-isothiazolone
- 5-chloro-2-methylisothiazolin-3-one
- 5-chloro-n-methylisothiazolin-3-one
- 5-chloro-N-methylisothiazolone
- CMIT
- HS 818
- Kathon CG 5243
- Methylchloroisothiazolinone
Frequently asked questions
What is 5-Chloro-2-methyl-4-isothiazolin-3-one (CMI) commonly used for?
CMI is primarily used as a broad-spectrum biocide in industrial water treatment, paints, coatings, adhesives, and personal care products to prevent microbial contamination.
What is the chemical formula and molecular weight of 5-Chloro-2-methyl-4-isothiazolin-3-one?
The chemical formula is **C₄H₄ClNOS**, and the molecular weight is **149.60 g/mol**.
How should 5-Chloro-2-methyl-4-isothiazolin-3-one be stored?
Store at **2–8°C** in a cool, dry place, away from incompatible substances, and ensure proper containment due to its hazardous nature.
What grades or purity levels of CMI does Molekula supply?
Molekula supplies **technical-grade CMI**, typically ≥95% purity, suitable for industrial applications requiring biocidal performance.
Can Molekula supply 5-Chloro-2-methyl-4-isothiazolin-3-one in bulk quantities?
Yes, Molekula can provide **bulk quantities** of CMI, with flexible packaging options (drums, IBCs) to meet large-scale industrial needs.
What documentation is provided with an order of 5-Chloro-2-methyl-4-isothiazolin-3-one?
Each order includes a **Certificate of Analysis (CoA)**, Material Safety Data Sheet (MSDS), and compliance documentation (e.g., REACH, GHS labeling) as required.
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