Cargo Tank Specification Requirements
Pipeline and Hazardous Materials Safety Administration · Oct 23, 1997 · Reference No. 97-0263
Reggie’s quick take
A home heating oil business asked four questions about cargo tank rules. The agency said a brand-new, unused cargo tank does not have to carry the § 180.415 inspection marking. Periodic inspections still apply to all DOT specification tanks, with set intervals for each type. The agency also said no Certificate of Compliance must be kept on file for a non-specification tank. For shipping papers, the agency said the quantity does not have to be changed after each delivery under § 172.202. For MC 330 and MC 331 tanks, "NQT" or "QT" marked on the specification plate at the right size under § 172.328 means separate stickers are not needed.
Written by AI (Claude) on Oct 22, 2026. Robots make mistakes and leave things out, so the letter below is what counts. Not legal advice.
This is in response to your letter regarding certain cargo tank specification requirements specified in the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180). I apologize for the delay in responding and regret any inconvenience it may have caused. Your questions are answered as follows:
Q1. Does a specification cargo tank that is new or less than five years old need to be marked in accordance with § 180.415(b) to display that it passed the internal visual inspection and the pressure test?
A1. All DOT specification cargo tanks are subject to the periodic inspections and tests listed in the table in § 180.407(c). They must be marked to show that each required inspection and test has been successfully completed as set forth in § 180.415. However, the HMR do not require that a new (unused) cargo tank be marked in accordance with § 180.415.
For internal visual inspections, all DOT specification cargo tanks must be tested at each five year interval and the following categories of tanks are required to be tested annually:
all insulated cargo tank except MC 330 and MC 331, MC 338; and
all other cargo tanks transporting lading corrosive to the tank.
Similarly, for pressure tests, some cargo tanks must be tested at five year intervals, some at two years and still others annually.
Q2. Does a Certificate of Compliance need to be on file for a non-specification cargo tank motor vehicle?
A2. The HMR do not require that a Certificate of Compliance be maintained on file for a non-specification cargo tank motor vehicle.
Q3. We operate a home heating oil business. Is it necessary to change the shipping paper each time a delivery is made?
A3. No, § 172.202 does not require that the quantity specified on the shipping paper be changed after a delivery is made.
Q4. If the specification plate on an MC 331 cargo tank is marked "NQT" or "QT" are "NQT" or "QT" stickers still required?
A4. No, § 172.328 requires that each MC 330 and MC 331 cargo tank must be marked near the specification plate with the letters "NQT" or "QT" in no less than 50mm (2 inches) in height. If the "NQT" or "QT" marking on your specification plate meets the size requirements specified in § 172.328, the display of markings on stickers is not needed.
I hope this information is helpful.
A letter of interpretation applies the regulations to the facts the requester described. It isn’t a regulation and isn’t legal advice. The agency’s copy.