Cylinders that are overfilled or heated are subject to dangerous high pressures and potential failure with increased temperature. These containers are not designed to hold pressure, and are subject to potential catastrophic failure as the ammonia warms to ambient temperature and internal pressures increase. There are several options for mitigating cylinders containing ammonia, however each has associated risks, and should be evaluated for safety based on the condition of the container and circumstances at the scene. Anhydrous ammonia is a dangerous liquefied gas, which poses a significant health threat if not handled properly. When approached with caution, training and protective equipment, it is possible to minimize the hazards posed by these cylinders, in order to manage them as safely as possible.
Anhydrous ammonia is colorless, liquefied gas under pressure.
Anhydrous ammonia is used extensively in agriculture where it is applied to the soil as a source of nitrogen. It is also used widely in refrigeration and cold storage facilities including building cooling systems. The odor threshold of ammonia is approximately 3-5ppm, and responders are generally aware of leaking cylinders by the odor at levels well below hazardous concentrations. High concentrations of ammonia vapor are visible as a white fog. At this concentration and in conjunction with the correct temperature and humidity level, ammonia vapor can also be a skin absorption hazard.