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Section §177.840: Class 2 (gases) materials

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 177.840 on the ECFR website

Interpretation Responses

Ref ID Date Company Name Individual Name Response Document
19-0122 Smart-Hose Technologies Mr. Daylen Borders View
16-0179 Mr. Dustan Burkey View
02-0140 Carlton W. Hendrix, Jr View
00-0004 It's A Gas, LLC Propane Cylinders Mr. Jeff Atkinson View
99-0040 Department of California Highway Mr. Paul Horgan View
08-0241 Corrigan Propane Mr. Bob Finn View
12-0121 National Transportation Safety Board The Honorable Deborah A.P. Hersman View
12-0132 Hogan Lovells US LLP Mr. Kenneth M. Kastner View
08-0027 Hawkins, Inc. Mr. Chris W. Gibson View
09-0236 Department of State INL/A Mr. James A. Sherman View
06-0162 Missouri Gas Energy Ms. Crystal Callaway View
12-0164 ARTA Group, Inc. Dr. Alex von Keitz View
06-0172 Texas Railroad Commission View
04-0117 Fomo Products Inc. Mr. Timothy J. Eberling View