Non-Specification Cargo Tanks

This is in reference to your July 12, 2001 letter concerning cargo tank specification requirements under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180). You asked several questions regarding state adoption of the HMR and closures on cargo tanks. Your questions are paraphrased and answered below in the order posed in your letter.

Q1. Does § 173.315(k) prohibit use of a non-specification cargo tank in liquefied petroleum gas service unless a State's laws specifically permitted such use in intrastate commerce prior to January 1, 1981?

A1. Yes.

Q2. If the answer to Q1 is "yes," and a State adopted or incorporated by reference the HMR prior to January 1, 1981 but had no law allowing the use of non-specification cargo tanks, can these tanks be used in that State?

A2. No. The State must have enacted a law prior to January 1, 1981 that specifically allowed the use of non-specification cargo tanks for the transportation of liquefied petroleum gas in intrastate commerce.

Q3. May transporters in Idaho, which adopted the HMR in 1980, use non-specification cargo tanks to transport liquified petroleum gas under the provisions of § 173.315(k)?

A3. No. The language in §§ 173.315(k) and 173.315(a) is similar. Both require a specific law enacted by the state allowing the use of non-specification cargo tanks prior to January 1, 1981 if the HMR had been adopted by state law. Absent a specific law allowing for the use of non-specification cargo tanks for liquified petroleum gas and anhydrous ammonia then their use was not authorized.

Also, you should be aware that we issued an exemption, DOT-E 12499 (enclosed) to permit the use of certain non-specification cargo tanks in Illinois.

Q4. Does § 173.24(f)(1)(iii) apply to all cargo tanks, both specification and non-specification, and particularly to MC 330, MC 331, and non-specification cargo tanks used to transport liquefied petroleum gas?

A4. Yes. Section 173.24 applies to all packages and packagings used for hazardous materials transportation.

Q5. Does § 173.24(f)(1)(iii) apply to both the liquid and vapor valves and closures on the tanks referenced in question 4 above?

A5. Section 173.24(f)(1)(iii) applies to all closures, but not vents. Vapor valves are considered vents, thus § 173.24(f)(1)(iii) would not apply to vapor valves.

Q6. Which valves and closures are required to be closed when a cargo tank is in transit?

A6. Generally, all valves and closures, except for vents and engine fuel line valves, must be closed when a cargo tank contains a hazardous material and is in transit. This requirement applies to all valves and closures that, if open, would result in a release of lading. (See § 173.24(g) for requirements applicable to vents and § 177.840(g) for requirements applicable to engine fuel line valves.) Intermediate isolation valves that may be present in a liquid discharge system need not be closed during transit.