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Interpretation Response #04-0221 ([Compressed Gas Association, Inc.] [Mr. R. J. McGrath])

Below is the interpretation response detail and a list of regulations sections applicable to this response.

Interpretation Response Details

Response Publish Date:

Company Name: Compressed Gas Association, Inc.

Individual Name: Mr. R. J. McGrath

Location State: VA Country: US

View the Interpretation Document

Response text:

Oct 1, 2004

Mr. R. J. McGrath
Technical Manager
Compressed Gas Association, Inc.                 Reference No. 04-0221
4221 Walney Road, 5th Floor
Chantilly, VA 20151-2923

Dear Mr. McGrath:

This responds to your August 23, 2004 letter regarding the requirements for inspection and testing of insulated MC-331 cargo tank motor vehicles (CTMVs) containing carbon dioxide, refrigerated liquid under § 180.407 of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180). You expressed concern about your members having to perform annual internal visual inspections on their MC 331 CTMVs based on amendments to the HMR adopted in final rules published under Docket No. RSPA 98-3554 (HM-213) on April 18 and September 3, 2003.

As shown in the table in § 180.407(c) of the HMR, insulated MC 331 CTMVs are excepted from the requirement to have an annual internal visual inspection. This exception granted for MC 330, MC 331, and MC 338 cargo tanks was not removed under the HM-213 final rule. Insulated MC 331 CTMVs are required to have an internal visual inspection at least once every five years. Because the insulation prevents a complete external visual inspection, those items able to be externally inspected must be inspected annually in accordance with 180.407(d) and noted in the inspection report. The annual, partial external visual inspection and a leakage test performed in accordance with § 180.407 (h) fulfill the annual inspection and test requirements applicable to MC 331 CTMVs in carbon dioxide, refrigerated liquid service.

The HM-213 final rule amended the HMR to clarify the external visual inspection requirements for insulated cargo tanks other than the insulated MC 330, MC 331, and MC 338s. As amended, the HMR allows insulated cargo tanks equipped with manholes or inspection openings to have either an internal visual inspection in conjunction with a partial external visual inspection or a hydrostatic or pneumatic pressure test. See note 4 following the table in § 1 80.407(c) and paragraph (d)(1).

I hope this information is helpful. If we can be of further assistance, please contact us.


Edward T. Mazzullo
Director, Office of Hazardous
Materials Standards


Regulation Sections

Section Subject
180.407 Requirements for test and inspection of specification cargo tanks