UN 1485 — Potassium chlorate

Potassium chlorate is a white crystalline solid or powder with a cooling, saline taste, used in the production of matches, fireworks, and other pyrotechnic devices. It is classified as a DOT class 5 oxidizer and is widely used in various industrial applications. First responders may encounter potassium chlorate in the event of a fire or explosion, and it is essential to handle it with caution due to its potential to accelerate burning and decompose explosively when heated. The scale of production and transport of potassium chlorate is significant, and it is crucial for emergency responders to be aware of its hazards and take necessary precautions. Potassium chlorate is also known by its synonyms, including chlorate of potash, potassium chlorate(V), and potcrate. Its CAS number is 3811-04-9.

Hazard overview: Potassium chlorate is a strong oxidizer that can accelerate burning and decompose explosively when heated, with a boiling point of 400C (752F) where it decomposes. It may ignite combustibles, such as wood, paper, oil, and clothing, and can react explosively with hydrocarbons. The substance is odorless and has a cooling, saline taste. When involved in a fire, potassium chlorate can release toxic fumes, including chlorine and potassium oxide. The LC50 value for potassium chlorate is not available, but it is known to be highly toxic and can cause severe health effects, including respiratory problems and skin irritation. In a worst-case scenario, potassium chlorate can explode from heat or contamination, causing significant damage and harm to people and the environment.

Response guidance: In the event of a potassium chlorate spill or fire, it is essential to isolate the area, with an initial isolation distance of 50m in all directions, and consider evacuation if a tank or rail car is involved in the fire, with an isolation distance of 800m. Emergency responders should use water spray, dry chemical, or CO2 to suppress the fire, avoiding organic materials and combustibles near the oxidizer. Decontamination is crucial, and CHEMTREC should be contacted in case of an emergency. The use of SCBA and Level B minimum PPE is required, with a focus on avoiding all ignition sources and contamination with organics.

Firefighter training notes: Emergency responders should be trained to handle potassium chlorate with caution, with a focus on avoiding ignition sources and contamination with organics. A common tactical error is underestimating the potential for explosion and fire, and it is essential to have a clear understanding of the substance's hazards and risks. The ICS position needs to be aware of the potential for potassium chlorate to accelerate burning and decompose explosively, and mutual aid criteria should be established in case of a large-scale emergency.

Regulatory context: Potassium chlorate is classified as a DOT class 5 oxidizer, with a packing group that is not available. The OSHA PEL/TLV for potassium chlorate is not well-established, but it is known to be highly toxic and can cause severe health effects. The substance is not on the CERCLA list, but it is essential to handle it with caution due to its potential to accelerate burning and decompose explosively.

Storage & handling: Potassium chlorate should be stored in a cool, dry place, away from incompatible materials such as hydrocarbons and combustibles. The temperature limit for storage is not available, but it is essential to avoid heat sources and ignition sources. Ventilation standards should be followed, and containers should be designed to prevent contamination and leakage.