72779 Sigma-Aldrich


97.0-103.0% (active substance, GC)

Synonym: 5-Chloro-2-(2,4-dichlorophenoxy)phenol, Irgasan, Triclosan

  • CAS Number 3380-34-5

  • Empirical Formula (Hill Notation) C12H7Cl3O2

  • Molecular Weight 289.54

  •  Beilstein/REAXYS Number 2057142

  •  EC Number 222-182-2

  •  MDL number MFCD00800992

  •  PubChem Substance ID 57652433

  •  NACRES NA.85



Related Categories A - K, Antibacterial, Antibiotics, Antibiotics A to Z, Antibiotics G-M,
Quality Level   200
biological source   synthetic
assay   97.0-103.0% (active substance, GC)
form   powder or crystals
impurities   ≤0.1% Water (Karl Fischer)
color   white
mp   55-59 °C
solubility   1 M NaOH: 5% at 25 °C, faintly turbid to clear (colorless solution)
Mode of action   enzyme | inhibits
antibiotic activity spectrum   fungi
SMILES string   Oc1cc(Cl)ccc1Oc2ccc(Cl)cc2Cl
InChI   1S/C12H7Cl3O2/c13-7-1-3-11(9(15)5-7)17-12-4-2-8(14)6-10(12)16/h1-6,16H


General description

Chemical structure: diphenyl ether derivative


5, 25 g in poly bottle


A component of cefsulodin-irgasan-novobiocin selection medium for Yersinia, a human pathogen that may contaminate animal-source food products. Because of its low antigenicity, irgasan is also a component of many antibacterial consumer products.

Biochem/physiol Actions

Irgasan is a broad spectrum antimicrobial agent. It is an inhibitor of the enoyl-ACP (acyl-carrier protein) reductase component of type II fatty acid synthase (FAS-II) in bacteria and Plasmodium. It also inhibits mammalian fatty acid synthase (FASN), and may have anticarcinogenic activity.

Other Notes

Keep container tightly closed in a dry and well-ventilated place. Keep in a dry place.

Safety & Documentation

Safety Information

Signal word 
Hazard statements 
Precautionary statements 
Personal Protective Equipment 
UN 3077 9 / PGIII
WGK Germany 
Flash Point(F) 
Not applicable
Flash Point(C) 
Not applicable


Certificate of Analysis (COA)

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Certificate of Origin (COO)

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Frequently Asked Questions

Which document(s) contains shelf-life or expiration date information for a given product?
If available for a given product, the recommended re-test date or the expiration date can be found on the Certificate of Analysis.
How do I get lot-specific information or a Certificate of Analysis?
The lot specific COA document can be found by entering the lot number above under the "Documents" section.
What isProduct 72779, Irgasan, soluble in?
Per the chemicals encyclopedia published by the Royal Society of Chemistry, 12th edition, Entry# 9790, Irgasan is not soluble in water, but it is readily soluble in alkaline solutions and many organic solvents.
What are other names besides Irgasan that Product 72779 may be referred to?
Irgasan may also be referred to as Triclosan and 5-Chloro-2-(2,4-dichlorophenoxy)phenol.
How do I find price and availability?
There are several ways to find pricing and availability for our products. Once you log onto our website, you will find the price and availability displayed on the product detail page. You can contact any of our Customer Sales and Service offices to receive a quote. USA customers: 1-800-325-3010 or view local office numbers.
What is the Department of Transportation shipping information for this product?
Transportation information can be found in Section 14 of the product's (M)SDS.To access the shipping information for this material, use the link on the product detail page for the product.
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Protocols & Articles


Determination of Triclosan in Environmental Waters

Introduction Triclosan is a chemical that has been used as an antibacterial agent in many soaps and a variety of other consumer and personal care products for many years. Because of its widespread us...
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