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Section §178.320: General requirements applicable to all DOT specification cargo tank motor vehicles

Below are the available interpretations and guidance for the given section. To return to the list of parts, use the Parts link above. If you do not see any guidance or interpretation information below, that means there is none available for the given part/section. Return to the search page to browse additional regulations sections.

PHMSA has published several Frequently Asked Questions (FAQ) documents on regulatory topics. Please review our FAQ documents below:

Additionally PHMSA has Hazardous Materials FAQs based on letters of interpretation on the following topics:

This section of the website provides the ability to find regulations information including regulations parts, content of sections, and interpretations for regulations sections. Below is a list of parts, identified by the part number and subject. To browse sections by part, click on the subject link below. You will be taken to the eCFR website to view sections for a part.

A written regulatory interpretation, response to a question, or an opinion concerning a pipeline safety issue may be obtained by submitting a written request to the Office of Pipeline Safety (PHP–30), PHMSA, U.S. Department of Transportation, 1200 New Jersey Avenue SE., Washington, DC 20590–0001 or at the email address: In addition to email address, the requestor must include his or her return address and should also include a daytime telephone number. Requests should be submitted at least 120 days before the time the requestor needs a response.

Note: electronic submission is provided as alternative to the 49 CFR Part 190.11(b) mail-in requirement.

The regulations text of the section can be found on the eCFR website. To view the regulations text, use the link below. For assistance, please send an email to

View section 178.320 on the ECFR website

Interpretation Responses

Ref ID Date Company Name Individual Name Response Document
23-0035 Superior Plus Propane Mr. Tim Decker View
16-0042 Truck Trailer Manufacturers Association John Freiler View
15-0079 Renaldo Sales & Service, Inc. Mr. Kerry Fitzgerald View
14-0010 Mr. David Ford View
10-0115 Jacobus Energy Mr. John Klein View
15-0049 Thompson Tank, Inc. Mr. David Thompson View
16-0009 Innovative Safety Solutions, Inc. Mr. Albert Calkin View
04-0242 Cusco Fabricators, Inc. Mr. Pardhasarathi Chilukuri View
14-0096 Evans Transportation Safety Consulting, LLC Mr. Joe Evans View
04-0038 McCarthy, Sweeney & Harkaway, P.C. Lawrence W. Bierlein, Esq. View
04-0174 California Environmental Protection Agency Mr. William V. Loscutoff View