...
Question 1: Who is subject to part 397?
Guidance:Part 397 applies to motor carriers that transport HM in interstate commerce in types and quantities requiring marking or placarding under 49 CFR 177.823. The routing requirements of part 397 establish guidelines State and Indian tribal routing agencies must employ in designating and/or restricting routes for the transportation of HM. Interstate motor carriers transporting HM, in interstate or intrastate commerce, must comply with the designations and restrictions established by the routing agencies.
Question 2: Is the interstate transportation of anhydrous ammonia, in nurse tanks, subject to part 397?
Guidance: The requirements of part 397 do not apply to the direct application of ammonia to fields from nurse tanks. However, part 397 does apply to the transportation of nurse tanks on public highways, when performed by interstate motor carriers.