Specialty Additives Available — Bulk Only

Methylchloroisothiazolinone (CMIT)

CAS 26172-55-4 · Formula C4H4ClNOS · MW 149.60 g/mol

A broad-spectrum isothiazolinone microbiostat supplied as an in-can preservative for industrial and water-based systems. It is used as a preservative and biocide in cosmetics and across industrial systems including metalworking fluids, latex paints, adhesives, and process waters.

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UN Number
UN 2922
Hazard Class
Class 8
HS Code
2934.99
At a Glance
Material Family
Specialty Additives
Record Type
Pure compound
Primary Role
Preservation · Biocidal Action
Functional Roles
METHYLCHLOROISOTHIAZOLINONE
PRESERVATIVE
Applications & Use Cases
  • Preservative: in-can and industrial preservative for water-based products
  • Metalworking fluids: microbial control in metalworking systems
  • Paints & adhesives: preservation of latex paints, glues, and coatings
  • Process water: microbiocide in industrial process and developing solutions
Physical Properties
Melting Point
54-55 °C
Density
For a mixture of 5-chloro-2-methyl-3(2H)-isothiazolone and 2-methyl-3(2H)-isothiazolone: Clear light amber liquid; density: 1.256
Solubility
Solubility in g/100 mL solvent: water, infinite
Vapor Pressure
0.018 mm Hg at 25 °C
Safety & Handling
Full SDS available on request

A grade-specific Safety Data Sheet (SDS) — with the complete hazard classification, handling precautions, and transport information — is supplied with every shipment and available on request. Confirm all safety and regulatory details against the SDS for your specific grade.

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DOT / UN Transport Classification
DOT hazard class 8 placard
UN / DOT NumberUN 2922
Hazard Class / DivisionClass 8
Proper Shipping NameCorrosive liquids, toxic, n.o.s.

Transport classification per the UN Model Regulations / 49 CFR 172.101 Hazardous Materials Table. Confirm against the grade-specific SDS (Section 14) before shipping.

HS / Tariff Classification
Harmonized System (HS) Code — 6-digit international heading
2934 . 99
Chapter 29
Organic chemicals
Heading 29.34
Internationally harmonized (WCO HS)
Subheading 2934.99
6-digit international code — national tariff line adds further digits
Chemical Identity
CAS Number
26172-55-4
Molecular Formula
C4H4ClNOS
Molecular Weight
149.60 g/mol
IUPAC Name
5-chloro-2-methyl-1,2-thiazol-3-one
INCI Name
METHYLCHLOROISOTHIAZOLINONE
PubChem CID
InChI Key
DHNRXBZYEKSXIM-UHFFFAOYSA-N
Synonyms & Trade Names
5-Chloro-2-methyl-4-isothiazolin-3-one Methylchloroisothiazolinone CMIT 5-Chloro-2-methyl-3(2H)-isothiazolone 5-Chloro-2-methyl-3-isothiazolone Kathon CG 5243 3(2H)-Isothiazolone, 5-chloro-2-methyl- 5-chloro-N-methylisothiazolone 5-chloro-2-methylisothiazolin-3-one 5-chloro-n-methylisothiazolin-3-one HS 818 n-methyl-5-chloroisothiazolone 4-ISOTHIAZOLIN-3-ONE, 5-CHLORO-2-METHYL- N-Methyl-5-chloroisothiazolin-3-one 5-chloro-2-methyl-3(2H)-isothiazolinone HS-818
Full Description

Methylchloroisothiazolinone (CMIT, CAS 26172-55-4) is a chlorinated isothiazolinone heterocycle. It is used as a preservative and biocide in cosmetics and across industrial systems including metalworking fluids, latex paints, adhesives, and process waters.

Frequently Asked Questions

What is isothiazolinone (CMIT/MIT) used for?

Methylchloroisothiazolinone (CMIT, CAS 26172-55-4), typically blended with MIT, is used as a preservative and biocide in water-based products. Applications include in-can preservation of latex paints, adhesives, and glues, microbial control in metalworking fluids, and microbiocidal treatment of industrial process and developing waters. It is supplied for industrial and formulating use.

What are isothiazolinones used for in detergents and industrial products?

Isothiazolinones such as the CMIT/MIT blend are used as preservatives to control microbial growth in water-based formulations, including detergents, latex paints, adhesives, metalworking fluids, and process waters. They protect the product from spoilage during storage and use. Loading should follow the SDS and formulation guidance.

What is the difference between CMIT and MIT?

CMIT is methylchloroisothiazolinone (the chlorinated isothiazolinone, CAS 26172-55-4) and MIT is methylisothiazolinone (the non-chlorinated analogue). They are commonly supplied together as a CMIT/MIT blend for broad-spectrum preservation. The blend ratio is confirmed on the Certificate of Analysis.

What is the CAS number and HS code for CMIT?

The CAS number is 26172-55-4 and the molecular formula is C4H4ClNOS, with HS classification 2934.99 (other heterocyclic compounds). Blend composition and active content are confirmed per lot on the Certificate of Analysis and SDS.

How is isothiazolinone (CMIT/MIT) supplied in bulk?

We supply CMIT/MIT preservative blends in bulk industrial packaging such as drums and IBC totes, with a CoA and SDS per lot. Request a bulk quote with your target quantity, active-content specification, and ship-to for current pricing.

Disclaimer. Information on this page — including properties, identifiers, hazard, transport (DOT/UN) and tariff (HS) classifications, and applications — is provided for general reference and is compiled from authoritative public sources (e.g. PubChem/ECHA, 49 CFR 172.101, the Harmonized Tariff Schedule). Values are typical and are not a guaranteed specification; the Certificate of Analysis (CoA) for the lot purchased governs. Products are sold for industrial and professional use only. Nothing here is a medical, health, or efficacy claim or advice. Always consult the current Safety Data Sheet (SDS) before handling, storage, transport or disposal, and confirm regulatory status, classification and suitability for your application and jurisdiction. Hazard, transport and tariff classifications must be verified for your specific shipment. RawSource makes no warranty, express or implied, and assumes no liability for use of this information. Trademarks. Third-party trademarks and brand names are the property of their respective owners; any reference is nominative — used only to identify a comparable product — and does not imply affiliation with, sponsorship by, or endorsement by the trademark owner.