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Section §172.505: Placarding for subsidiary hazards

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 172.505 on the ECFR website

Interpretation Responses

Ref ID Date Company Name Individual Name Response Document
19-0020 Zee Company Ricky Pruitt View
13-0052R Simpson Strong Tie Company, Inc. Densie Nguyen View
17-0109 Hunting Titan, Inc Joe Murphy View
07-0081 Pilot Chemical Company Mr. Matthew J. Leary View
02-0056 Allied Universal Corp. Robin J. Eddy View
09-0166 Georgia Department of Public Safety Capt. Bruce Bugg View
02-0177 Brenntag Mid-South, Inc. Fred E. Nichols View
02-0089 Honeywell International, Inc. Barbara Konrad View
11-0298 Public Utilities Commission of Ohio Transportation Department Compliance Division Mr. Tom Forbes View
07-0230 Pipe Recovery Systems, Inc. Mr. Michel Chammas View
07-0071 PCS Sales, (USA) Inc Ms. Tracey G. Smith View
09-0201 Hazmat, Inc. Mr. Paul J. Dambek View
11-0107 Chammas Cutter, Inc. Mr. Michael Chammas View