The Journal of HazMat Transportation's™ Exclusive Comments on U.S. DOT Letters of Interpretation of the HMR

摘要

Let's take a look at PHMSA's letter of interpretation dated September 13, 2021 reference number 21-0051 to Railsback Hazmat Safety Professionals, LLC regarding cargo tanks commonly known as a "nurse tank". See the letter on page 59. It might be helpful to review what a nurse tank is to get a better understanding of the nature of the questions and answers. A nurse tank is a non USDOT specification cargo tank used to transport anhydrous ammonia for agricultural purposes. Anhydrous ammonia is a very concentrated form of nitrogen and in this application, it is used as a fertilizer. Anhydrous ammonia is used extensively as a nitrogen source for crops such as corn and wheat. Nurse tanks are used to transport the anhydrous ammonia from the ag retailer's bulk storage tanks to the farm. Anhydrous ammonia is injected into the soil typically in the Spring and Fall. It is estimated that in the United States there are around 220,000 anhydrous ammonia nurse tanks in service.