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Letters of Interpretation

PHMSA has published several Frequently Asked Questions (FAQs) documents on programmatic topics. Please review these documents here at: https://www.phmsa.dot.gov/about-phmsa/phmsa-faqs.

Additionally, Office of Hazardous Materials Safety has published Hazardous Materials FAQs based on letters of interpretation on the following topics:

Office of Hazardous Materials Safety: For questions about transporting hazardous materials, needing clarifications of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180), or requesting a formal letter of interpretation, please go to the Hazardous Materials Information Center (HMIC) page for contact information (phone and email address).

Office of Pipeline Safety: 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: pipeline_interp_submittal@dot.gov. 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.

This section of the website below provides the ability to find regulations information including regulations parts, content of sections, and interpretations for regulations sections. A list of parts, identified by the part number and subject is also provided. 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.

The eCFR is also searchable by keyword and other available options on the eCFR website. To search and browse regulations using the eCFR website, use the link below. For assistance, please send an email to PHMSA.Webmaster@dot.gov.

Search the eCFR

Interpretations Reference #

Search Tip: Use quotation marks to search for commonly used phrases, such as “gas transmission” or “cargo tank motor vehicle.”
E.g., 02/09/2021
E.g., 02/09/2021
Ref ID: Date Company Name Individual Name Response Document
22-0036 Haz-Mat One Mr. Travis Hillmer View
23-0021 W. R. Grace & Co – Conn. Paul Errichetti View
22-0126 UL Solutions Mr. Kevin Skerrett View
22-0057 Department of The Army Mr. Thomas Kudasz View
22-0116 Total Technic Total Technic View
23-0004 APRAGAZ (Notified Body 0029) Chris Vleugels View
23-0034 KTM North America, Inc. Mr. John Hinz View
22-0117 Mr. Nick Wright View
23-0036 National Association of Fire Equipment Distributors Mr. David A. Pelton View
23-0015 UralKali Trading Marcel Cisneros View
22-0130 American Cylinder and Safety Myles Leland TenBroeck View
23-0017 Vantage Specialties, Inc. Mr. Donovan Robin View
PI-23-0009 CH-IV International Mr. Lex De Groot View
22-0118 Tanner Industries, Inc. James Klucsarits View
23-0031 Essex Industries, Inc. Ario Estrada View
22-0078 Crestwood Transportation Mr. Jared Sharp View
22-0101 Entegris Inc. Mr. James V. McManus
22-0033 DOT Safety Solutions Randy Decker View
23-0019 AET Environmental, Inc. Frank Virginia View
23-0001 Petra Industries, LLC Mr. Tyler Scott View
23-0033 Sensors, Inc. Mr. Doug Heisler View
23-0006 Sea Lamprey Control Centre Mr. Paul Kyostia View
PI-23-0004 Integrity Plus Mr. Pat Westrick View
22-0132 The Hartford Steam Boiler Inspection and Insurance Company Bruce K. Redfield View
22-0067 Kidde Aerospace and Defense Mark Fazzio View
22-0092 Independent Cylinder Training Amy Morgan Bruecks View
23-0028 Arkema Inc. Christina M. Kurtz View
23-0005 Steve Laughlin View
PI-23-0002 Illinois Commerce Commission Mr. Matthew L. Harvey View
PI-23-0003 Riverfront Exploration, LLC Ms. Jennifer Sebo View
22-0014 I.C.E. Service Group & SPS Strategic Packaging Systems Mr. Kurt Colborn View
PI-23-0001 Pacific Gas & Electric Company Mr. Philip Simpkins View
22-0052 Arkema – Health Environment and Safety Steve Schulte View
22-0109 Pacific Gas & Electric Timothy Hewitt View
22-0047 Bureau Veritas Inspection and Insurance Company Edgar A. Whittle View
PI-22-0015 Anheuser-Busch, LLC Mr. Kevin Fahrenkrog View
PI-23-0008 Pennsylvania Public Utility Commission Mr. Adam D. Young View
22-0025 University of Rhode Island Nic Englehart View
22-0129 American Bureau of Shipping Ms. Simone Goncalves View
22-0058 Heil Trailer Mr. Charles Gilson View
22-0095 Environmental Resource Center Kristie Absher View
23-0010 Advanced Printing Solutions Bill Booth View
PI-11-0013 New Mexico Gas Company Ms. Deborah Brunt View
22-0062 Larson Berg & Perkins PLLC James A. Perkins View
22-0085 Aggreko Mr. Chad Thibodeaux View
22-0134 SMBC Rail Services LLC Dan Welch View
22-0069 Senergy Petroleum Mr. Deven Hallen View
22-0121 DOT Training Solutions Arturo Prado View
22-0122 David Fletcher View
22-0094 AllTranstek, LLC Larry Loman View