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 2000 · 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
These pack sizes aren't a limit. Molekula manufactures, sources and repacks to order — if you need 500 kg and only see 1 kg listed, . We quote from grams to multi-tonne.
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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.
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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