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Section §172.500: Applicability of placarding requirements

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 172.500 on the ECFR website

Interpretation Responses

Ref ID Date Company Name Individual Name Response Document
22-0050 Mayo Clinic Mr. Travis Brandt View
21-0032R Bettis Asphalt & Construction, Inc. Cole Andersen View
20-0064 MRIGlobal-NCR Malcolm Smith View
20-0007 Oxyde Chemicals, Inc. Mr. Adrian Medina View
14-0031 YRC Freight, Inc. Ms. Susan D. Camara View
07-0201 Q. A. Safety Mr. Ray L. Faucheux, Jr. View
06-0072 HB Fuller Company Mr. Eugene J. Secor View
03-0148 Horizon Lines Mr. Cliff Bartley View
98-0423 Mr. Patrick G. Kruger View
04-0260 J & R Brokerage, Inc. Mr. John F. Martin View
15-0024 Hazardous Materials Response Unit Officer Daniel Voelker View
14-0231 PPG- Comex Mr. Israel Villarello View
13-0069 Go Glow Placard Mr. Patrick D. Nimtz View
04-0132 International Association of Fire Chiefs Chief Ernest Mitchell View
15-0243 Environmental Health & Safety Ms. Marilyn Winterburg View