5-Chloro-2-methyl-3(2H)-isothiazolone

Drug ingredient

CAS 26172-55-4

EPA’s 2023 records show zero U.S. production for this drug ingredient.

US productionZero

Import volumeCBI

Confidential Business Information. The EPA withholds this volume because publishing it could reveal the reporting company's trade secrets.

Top sourceNo public record

At least one company claimed its 2023 production or import volume for this chemical as confidential, so EPA withholds it.

Why supply is unknown

Production is reported production, not a complete census of factories. Production reporting year: 2023.

Where It Comes From

EPA reports by year

2023: US production Zero · Imports Confidential
2019: US production Zero · Imports 7.7K lb

Domestic parents -- activity not disclosed (1)

EPA records name a US company for this chemical but do not disclose whether the company made it here or imported it.

Polyventive

EPA-registered importers (2)

Companies that report making or importing this chemical to the EPA. Registration is US-centric and does not indicate import origin.

Brenntag

The Sherwin Williams

Why It Matters

Sectors

HealthTransportationConstructionPlastics & RubberConsumer ProductsPaints & Coatings

Downstream Uses

Appears in 1 drug and cosmetic product listings (FDA).

•Anubis Barcelona Regul Oil

FDA Shortage Status

Whether any manufacturer currently reports this drug as in shortage on the FDA Drug Shortages database. "Active Shortage" means at least one presentation has status "current."

No FDA shortage records

Industrial Uses

Used in 7 sectors as 1 functional role.

•Preservative in Transportation Equipment ManufacturingProcessing—incorporation into article
•Preservative in Furniture and Related Product ManufacturingProcessing—incorporation into article
•Preservative in Plastics Material and Resin Manufacturing (3%)Processing—incorporation into formulation, mixture, or reaction product
•Preservative in Paint and Coating Manufacturing (4%)Processing—incorporation into formulation, mixture, or reaction product
•Preservative in Not Known or Reasonably AscertainableProcessing—incorporation into article
•Preservative in Wood Product ManufacturingProcessing—incorporation into article
•Preservative in Adhesive Manufacturing (97%)Processing—incorporation into formulation, mixture, or reaction product

Vendor Pricing

$0.49/gAaron Chemicals LLC

CountryHong Kong

Pack$243.00 / 500 g

Purity2.5%

Vendors11 available

Prices reflect listed pack sizes. Small research packs run far above bulk rates.

10 more vendors

Vendor	Country	$/g	Pack	Purity
Angene Chemical	China → Hong Kong	$0.52	500 g	2.5%
Combi-Blocks, Inc.	United States	$1.50	500 g	70%
A2B Chem LLC	United States	$1.59	500 g	68%
AA BLOCKS	United States	$1.68	500 g	14%
Biopharma PEG Scientific Inc.	United States	$2.40	100 g	96%
AstaTech, Inc	United States	$2.50	100 g	14%
AK Scientific, Inc.	United States	$2.50	100 g	14%
Angene International Limited	United States	$7.32	25 g	14%
Fluorochem UK	United Kingdom	$9.72	25 g	68%
Angene	China → Hong Kong	$4266.67	30 mg	2.5%

Chemical Identity

CAS26172-55-4

PubChem CID33344

DTXSIDDTXSID9034286

FormulaC4H4ClNOS

Mol. Weight149.6 g/mol

SMILESCN1C(=O)C=C(S1)Cl

Data Sources

EPA CompTox (DSSTox) · DTXSID9034286Retrieved 2026-04-06
PubChem · compound 33344Retrieved 2026-04-06
EPA Chemical Data ReportingReporting year: 2023 · Retrieved 2026-10-04
EPA Chemical Data ReportingReporting year: 2023 · Retrieved 2026-10-04

← Back to Dashboard ← Back to Health

Brief citations

5-Chloro-2-methyl-3(2H)-isothiazolone (CAS 26172-55-4) https://chemicalindependence.com/chemical/26172-55-4/ EPA CompTox (DSSTox): DTXSID9034286. Retrieved 2026-04-06. https://comptox.epa.gov/dashboard/chemical/details/DTXSID9034286 PubChem: 33344. Retrieved 2026-04-06. https://pubchem.ncbi.nlm.nih.gov/compound/33344 EPA Chemical Data Reporting: 26172-55-4. Reporting year: 2023. https://www.epa.gov/chemical-data-reporting EPA Chemical Data Reporting: CAS 26172-55-4. Reporting year: 2023. https://www.epa.gov/chemical-data-reporting