Cargo Tank Specification Requirements

This responds to your letter, dated October 29, 1999, concerning cargo tank specification requirements in the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180). Specifically, you ask about a design modification to MC 307, MC 312, DOT 407, and DOT 412 specification cargo tanks to equip them with an internal agitation system driven by a power source located outside the cargo tank.

Your letter suggests that you are considering manufacturing new cargo tanks equipped with the internal agitation system rather than modifying existing cargo tanks. You should be aware that MC 307 and MC 312 specification cargo tanks have not been authorized for new construction since August 31, 1995 (see § 180.405(b)).

The design and construction requirements for DOT 407 and DOT 412 specification cargo tanks are in § 178.345 of the HMR. The regulations do not prohibit a design of the type you describe. Each cargo tank motor vehicle design type must be approved by a Design Certifying Engineer (see § 178.320(b)). In addition, each finished cargo tank motor vehicle must be inspected by an Authorized Inspector or a Registered Inspector, as applicable (see § 178.345-1 (e)).

Generally, MC 307, MC 312, DOT 407, and DOT 412 specification cargo tanks are authorized for bulk shipments of flammable liquids, including waste flammable liquids. Packaging requirements for bulk quantities of a specific hazardous material can be found in column 8C of the Hazardous Materials Table in § 172.101 of the HMR. You should consult the section of the HMR referenced in column 8C for the specific hazardous material you are transporting for the packagings authorized for transportation and any special requirements that also apply.

Additional requirements for transporting bulk quantities of hazardous materials are in Part 173, Subpart B - Preparation of Hazardous Materials for Transportation.