A description of agricultural releases of anhydrous ammonia in Minnesota
Anhydrous ammonia releases were reviewed during a three-year period (1995 to 1997) by the Minnesota Hazardous Substances Emergency Events Surveillance Program. Of the 800 hazardous substances emergency events recorded, 97 (12.1%) involved anhydrous ammonia. This review found that 51% of the total quantity of anhydrous ammonia released in emergency events came from agriculture (92% excluding one train car event). Emergency events involving anhydrous ammonia were almost twice as likely to involve victims than other events. However, nonagricultural and agricultural anhydrous ammonia emergency events had similar probabilities for victims. Nonagricultural anhydrous ammonia events were more likely to result in evacuations than agricultural anhydrous ammonia events. Given the large amount of agricultural anhydrous ammonia used every year in Minnesota, an average of 690 million pounds per year, the tiny fraction (0.005%) of agricultural ammonia released in emergency events, and the small number of victims and evacuations, agricultural ammonia is being handled relatively safely. Nevertheless, most accidents involving agricultural ammonia could be prevented if operators would practice relatively simple safety precautions.