Sodium chlorate: properties, production, uses and safety

Physical and chemical characteristics

Sodium chlorate contains sodium cations and chlorate anions; basic information on the constituent ions can be found at sodium and chlorate. It is a powerful oxidizer (oxidizing agents), releases oxygen on decomposition and can vigorously promote combustion of organic and reducing materials. Typical characteristics include:

• Formula: NaClO3
• Appearance: white crystalline solid
• Solubility: readily soluble in water
• Chemical behavior: oxidizing, decomposes above certain temperatures to release oxygen

Production

Commercial sodium chlorate is most commonly produced by the electrolytic oxidation of sodium chloride solutions (brine). The industrial process uses controlled electrolysis at elevated temperatures and converts chloride ions through intermediate species to the chlorate ion; for process details see electrolysis of brine. The product is isolated as a crystalline salt for storage and transport.

Uses and applications

Because of its strong oxidizing power, sodium chlorate has been used in several sectors. Historically and presently important uses include:

• Non-selective herbicide and desiccant for vegetation management (herbicide).
• Bleaching agent and chemical oxidant in the pulp and paper industry.
• Intermediate in the manufacture of other chlorine-containing chemicals and laboratory reagent use.

Safety, toxicity and environmental considerations

Sodium chlorate is toxic when ingested and can cause oxidative damage to biological tissues, including the formation of methemoglobin. It is hazardous because it can accelerate combustion and may react violently with organic matter or strong reducing agents; general information on ionic hazards is available at ion safety. Many jurisdictions restrict or regulate its use as a herbicide due to risks to non-target plants, soil and water. Advice on safe handling and emergency measures is provided through industrial safety sources and chemical suppliers (chlorate information, oxidizer guidance).

Notable distinctions and precautions

Unlike chlorine gas or sodium hypochlorite, sodium chlorate is a stable solid but remains an active oxidant. It should be stored separately from organic materials, acids and reducing agents. Disposal and environmental controls must follow local regulations because of persistence and potential toxic effects on ecosystems.