Ammonium Nitrate

CAS RN: 6484-52-2

Fire Fighting Procedures

Cool exposed containers with water. Continue cooling after fire has been extinguished.
Use flooding quantities of water. Fight fire from protected location or maximum possible distance. Approach fire from upwind to avoid hazardous vapors & toxic decomposition products. Fire situations may require evacuation.
If material on fire or involved in fire: Dangerously explosive. Do not fight fires in a cargo of explosives. Evacuate area and let burn. /explosives/
If material on fire or involved in fire: Flood with water. Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible. /oxidizer and liquid (oxidizer)/
Confinement and/or the addition of fuel to ammonium nitrate creates a real danger of explosion. The addition of heat when either of these conditions exists can lead to disaster. Accordingly, the responder should quickly assess if ammonium nitrate has been involved in the fire and whether the ammonium nitrate has been compromised in any of these ways, and plan the fire response accordingly.
If firefighters consider it safe and appropriate to respond to a fire involving ammonium nitrate, then the following information should be considered: ammonium nitrate fires should be fought from protected locations or maximum possible distance. Approach a fire involving or close to ammonium nitrate from upwind to avoid hazardous vapors and toxic decomposition products. Self-contained breathing apparatus (SCBA) of types approved by the National Institute for Occupational Safety and Health (NIOSH) should be used to protect personnel against gases. Use flooding quantities of water from a distance as promptly as possible. It is important that the mass of ammonium nitrate be kept cool and the burning be quickly extinguished. Keep adjacent fertilizers cool by spraying with large amounts of water. When possible and appropriate, only use unmanned hose holders or monitor nozzles. Do NOT use steam, CO2, dry powder or foam extinguishers, sand or other smothering agents. Ensure maximum ventilation of the ammonium nitrate storage container as quickly as practical to prevent heat and pressure buildup. This is different than ensuring maximum ventilation of the entire building or structure where the ammonium nitrate is stored. Ventilation of the structure should be conducted only in a manner to limit fire spread and growth and should be minimized until a suppression water supply is established. If practicable and safe to do so, attempt to prevent ammonium nitrate from entering the drains where explosive confinement could occur. Remember ammonium nitrate may be washed into drains by fire water, but it can also melt and flow without impetus from water. Prevent or minimize contamination of water bodies or streams to reduce the potential for environmental effects.
Firefighters should not fight an ammonium nitrate fire and everyone, including fire fighters, should be evacuated to a safe distance if they observe any of the following: A fire involving ammonium nitrate is judged to be out of control; The fire is engulfing the ammonium nitrate; or Brown/orange smoke is detected, indicating the presence of nitrogen dioxide (which is toxic); or A rapid increase in the amount/intensity of smoke or fire in the area of ammonium nitrate storage.
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