Tennessee Code Title 43. Agriculture and Horticulture § 43-11-303

(a) “Anhydrous ammonia,” when used exclusively for commercial fertilizer, is, for the purpose of this part, defined as follows: anhydrous ammonia contains eighty-two percent (82%) nitrogen. At atmospheric pressure, ammonia is a gas that exists as a liquid below minus twenty-eight degrees Fahrenheit (-28° F.), and boils at this temperature. In commerce, ammonia is compressed to a liquid and stored under pressure. The gauge pressure is seventy-five pounds (75 lbs.) per square inch at fifty degrees Fahrenheit (50° F.), and one hundred ninety-seven pounds (197 lbs.) per square inch at one hundred degrees Fahrenheit (100° F.). The pressures exerted by anhydrous ammonia are dangerous unless the proper safety devices are installed in the equipment and care is used in handling.

(b) “Dealers in anhydrous ammonia and equipment,” as covered by this part, are all persons, firms, corporations or associations who buy and sell or distribute at wholesale or retail to users and consumers, anhydrous ammonia as a fertilizer, or equipment used in the installation, storage, handling, utilization and dispensing of anhydrous ammonia as a fertilizer. Manufacturers of anhydrous ammonia, or manufacturers or jobbers that wholesale anhydrous ammonia equipment, when sold to dealers or distributors, as defined in this part, or any person or persons, firms or corporations owning or maintaining storage facilities for anhydrous ammonia as a fertilizer for their own use and accommodation, and for the use and accommodation of their tenant or sharecropper, are not to be classed as dealers within the meaning and intention of this part.