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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). Pending interpretation letters that are under review by the Office of Hazardous Materials Safety can be found at Pending Hazardous Materials (Hazmat) Interpretations.  

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.

Interpretation letters under review are available at the Office of Pipeline Safety’s Interpretation Review page. To submit comments on an interpretation under review, proceed to the Interpretation Review page, locate the interpretation to comment on, and click the appropriate link to submit a comment on the corresponding interpretation. Comment submissions will be accepted for 30-days after the interpretation letter is posted.

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
06-0108 Con-way Mr. Robert Petrancosta  View
05-0239 CTC Certified Training Co Mr. Darrell K. Garton View
01-0082R MN DOT Office of Motor Carriers Mr. Michael Ritchie View
06-0031 Mr. John Ramsey View
06-0091 Buckingham, Doolittle & Burroughs, LLP Mr. David J. Hrina  View
06-0064 Catalina Cylinders Mr. E.A. Ward Dekker, Jr View
06-0077 Scopelitis, Garvin, Light & Hanson Mr. Timothy W. Wiseman View
06-0104 CP Industries Mr. G. A. Hayden, PE View
06-0098 PTP Consulting, Inc. Ms. Carol Brozosky, CET, CHMM View
06-0081 Gas Service and supply Mr. Don Lampshire View
06-0041 ShipMate, Inc. Mr. Steven Charles Hunt  View
06-0043 NRS Logistics, Inc. Mr. David Hiromura  View
06-0095 Ultimate Contract Services, Inc. Mr. Thomas Radwick View
06-0016 Transport Management Group Mr. Timothy Wagner View
06-0096 KPA, LLC Mr. Brent J. Hoberg  View
06-0070 Culver Enterprises, Inc. Mr. John Culver View
05-0311 MHF Logistical Solutions Mr. Kurt Colburn View
05-0289 ShipMate, Inc. Mr. Steven Charles Hunt View
06-0083 Transportation Systems Solutions Mr. Peter Olsen View
06-0052 The Dow Chemical Company Mr. Phil Stewart View
05-0195 Goodall Rubber Company Mr. Brad Ferstan View
06-0055 Ferroatlantica Mr. Edward Hopkins View
06-0062 DLA Piper Rudnick Gray Cary US LLP Mr. Paul D. Ackerman View
05-0208 American Pyrotechnics Association Ms. Julie L. Heckman View
05-0200 Mr. Ed Mansell View
06-0044 Gallagher & Howarth, P.C. Ms. Liese G. Howarth View
06-0053 Pfizer, Inc. Ms. Debbie Hape View
06-0054 Scranton Cooperage, Inc. Mr. Eric Spatt View
06-0065 Neupauer Industries Inc. Mr. Harold Zimmerman View
06-0049 Vinson & Elkins Thomas H. Wilson View
05-0191 Industrial Health and Safety Consultants, Inc. Denese A. Deeds, CIH View
05-0120 Cayias Consulting Mr. John Cayias View
06-0050 REG Scan Mr. Russ Shanahan View
04-0119 Monsanto Company Mr. William J. Briner View
06-0056 NACA Logistics Mr. Eric Fischer View
05-0196 Arkansas Department of Environmental Quality Mr. Robert Hunter View
05-0109 GATX Rail Mr. Doug Mullins View
06-0037 Waste Technology Services, Inc. Ted L. Nebrich, Jr., CHMM, QEP, REM View
06-0032 Mr. Thomas Richichi View
05-0290 Galls/Aramark Inc. Mr. Carl Jackson View
06-0021 Intertek Caleb Brett New Orleans Mr. Scott Fenwick View
06-0042 State of New Jersey Mr. Robert Gomez View
06-0039 Shane Havoc Consulting, LLC Dr. Gregory J. Sutherland  View
05-0218 City Carbonic Sales & Service Ms. Amy Morgan Bruecks View
06-0057 Akzo Nobel Chemicals Inc. Mr. Mark A Connolly View
06-0047 Tyco Specialty Products Ms. Nicole Curcio View
06-0019 3M Company Mr. Richard L. Sheehan View
06-0036 Greif Mr. Rich Kovaleski View
06-0012 Mr. Anthony J. Kesslak View
06-0025 University of New Hampshire Mr. Andy Glode View