Sodium dichloroisocyanurate
[CAS# 2893-78-9]

Identification

• Classification: Organic raw materials >> Organometallic compound >> Organic sodium
• Name: Sodium dichloroisocyanurate
• Synonyms: 1-Sodium-3,5-dichloro-s-triazine-2,4,6-trione; Dichloro-s-triazine-2,4,6-(1H,3H,5H)-trione sodium salt; Dichloroisocyanuric acid sodium salt
• Molecular Formula: C₃Cl₂N₃NaO₃
• Molecular Weight: 219.94
• CAS Registry Number: 2893-78-9
• EC Number: 220-767-7
• SMILES: C1(=NC(=O)N(C(=O)N1Cl)Cl)[O-].[Na+]

Properties

• Melting point: 250 °C (Decomposes) (Expl.)
• Solubility: water: 30g/100ml (25 °C) (Expl.)

Safety Data

• Hazard Symbols: GHS03;GHS07;GHS09 Danger
• Risk Statements: H272-H302-H319-H335-H400-H410
• Safety Statements: P210-P220-P261-P264-P264+P265-P270-P271-P273-P280-P301+P317-P304+P340-P305+P351+P338-P319-P330-P337+P317-P370+P378-P391-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	4	H302
Acute hazardous to the aquatic environment	Aquatic Acute	1	H400
Chronic hazardous to the aquatic environment	Aquatic Chronic	1	H410
Specific target organ toxicity - single exposure	STOT SE	3	H335
Oxidising solids	Ox. Sol.	2	H272
Eye irritation	Eye Irrit.	2	H319
Skin corrosion	Skin Corr.	1B	H314
Serious eye damage	Eye Dam.	1	H318
Skin corrosion	Skin Corr.	1A	H314
Oxidising liquids	Ox. Liq.	2	H272
Skin irritation	Skin Irrit.	2	H315
Oxidising solids	Ox. Sol.	2	H271

• Transport Information: UN 2465

Discovery and Applications

Sodium dichloroisocyanurate (NaDCC) is an organic chlorine-releasing compound widely used as a disinfectant, sanitizer, and bleaching agent. It is a sodium salt of dichloroisocyanuric acid, generally encountered as a white crystalline powder or granular solid with high stability under dry conditions. The compound’s molecular formula is C₃Cl₂N₃NaO₃, and it belongs to the family of chlorinated isocyanurates, which are valued for their ability to release free available chlorine in aqueous solution.

NaDCC was developed in the mid-20th century as a safer, more stable alternative to sodium hypochlorite for applications requiring disinfection and sanitation. Its stability in solid form and relatively low corrosivity made it suitable for long-term storage and transport, especially in humid or tropical climates. Upon dissolution in water, sodium dichloroisocyanurate hydrolyzes to release hypochlorous acid, the active antimicrobial species responsible for its disinfecting action. The rate of chlorine release is slower than that of sodium hypochlorite, providing a more sustained antimicrobial effect.

The compound is extensively used in water treatment, particularly for drinking water disinfection in emergency relief operations, military field use, and rural community supplies. It is also applied in swimming pool sanitation, where it helps maintain residual chlorine levels to control bacterial, viral, and algal contamination. In healthcare environments, NaDCC is employed for surface disinfection, instrument sterilization, and decontamination of medical waste, as it is effective against a broad spectrum of pathogens, including bacteria, viruses, fungi, and protozoa.

Industrial applications of sodium dichloroisocyanurate extend to food and beverage processing facilities, where it is used to sanitize equipment, containers, and production surfaces without leaving harmful residues when used appropriately. In the textile and paper industries, NaDCC functions as a bleaching agent, taking advantage of its oxidative capacity to remove color impurities.

Its safety profile has been evaluated in terms of handling, storage, and environmental impact. While the solid compound is stable under normal conditions, it should be kept away from moisture and incompatible substances such as acids and reducing agents. In aqueous solution, the free chlorine gradually decomposes, which limits long-term storage of prepared solutions. Toxicological assessments indicate that, at recommended concentrations, NaDCC is safe for use in potable water disinfection, though ingestion of concentrated material can cause irritation or injury. Its breakdown products are environmentally degradable, with cyanuric acid being the primary residual component.

In addition to routine sanitation, sodium dichloroisocyanurate has played a role in controlling infectious disease outbreaks, where rapid deployment of effective water disinfection measures is critical. The combination of portability, stability, and potent antimicrobial action has made it a standard tool in humanitarian and disaster relief kits worldwide.

References

2023. Disinfectant sodium dichloroisocyanurate synergistically strengthened sludge acidogenic process and pathogens inactivation: Targeted upregulation of functional microorganisms and metabolic traits via self-adaptation. Water Research, 247.
DOI: 10.1016/j.watres.2023.120787

2021. A sodium dichloroisocyanurate-based conditioning process for the improvement of sludge dewaterability and mechanism studies. Journal of Environmental Management, 287.
DOI: 10.1016/j.jenvman.2021.112020

2020. Comparison of the Biocidal Efficacy of Sodium Dichloroisocyanurate and Calcium Hydroxide as Intracanal Medicaments over a 7-Day Contact Time: An Ex Vivo Study. Journal of Endodontics, 46(9).
DOI: 10.1016/j.joen.2020.05.011