USA Banner

Official US Government Icon

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure Site Icon

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation


Section §172.313: Poisonous hazardous 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 172.313 on the ECFR website

Interpretation Responses

Ref ID Date Company Name Individual Name Response Document
23-0066 W.R. Grace & Co - Conn. Mr. Paul Errichetti View
00-0256 Air Products and Chemicals, Inc. Mr. Donald R. Silfies View
07-0019 Hy Yield Bromine Inc. Mr. Byver Daniell View
06-0213 Allied Universal Corporation Ms. Robin J. Eddy Bolte View
05-0043 Allied Universal Corporation Ms. Robin J. Eddy Bolte View
98-0416 Degussa Corporation Mr. John Foglio View
13-0221 3M Center Mr. William Gramer View
06-0224 Rohm and Haas Company Ms. Carrie Wayne View
09-0039 HazMat Resources, Inc. Mr. Danny Shelton View
00-0360 Conway Transportation Services Mr. Robert Petrancosta View
10-0037 MST2 USCG Sector LA-LB, Facilities Branch Christopher H. Smith View