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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
PI-15-0005 Bangor International Airport Mr. Anthony P. Caruso View
15-0062 Authorized Testing Inc, IA02 Mr. David Bacca View
15-0141 Daniels Training Service Mr. Daniel Stoehr View
15-0134 Alaska Airlines - SEADG Mr. Mike Tobin View
15-0120 Daniels Training Services Daniel Stoehr View
15-0111 Oxus America Mr. Ryan Lenaric View
15-0121 The Lane Construction Corporation Ms. Michele A. Jacobs View
14-0230 The Chlorine Institute Ms. Robyn Kinsley View
15-0047 Columbus Chemical Industries Ms. Laura Buholca View
15-0103 VEOLIA NORTH AMERICA Ms. Jennifer Eberle View
15-0094 Viking Packaging Mr. Les Adolph View
15-0024 Hazardous Materials Response Unit Officer Daniel Voelker View
CHI-15-0167 Bruce D. Green View
15-0019 W.E Train Consulting Mr. Gene Sanders View
15-0109 US Ecology - Regional Office Mr. Brian Kucharski View
15-0156 Toyota Materials Handling Northeast Inc. Mr. Partlow View
15-0093 Wiley Rein LLP Mr. Roger Miksad View
15-0072 Compliance Plus Servicves, Inc. Ms. Denise Ernest View
15-0129 Crop Production Services, Inc Mr. Clayton Droste View
15-0114 Dorsey & Whitney LLP Mr. Mark Kaster View
15-0009 Mr. Mike Revis View
15-0041 Bombardier (Aerospace) Mr. Jeff Christafore View
15-0128 Ground Up Road Construction Inc. Scott Stultz View
15-0090 Inova Diagnostics Allison Fowler View
15-0127 Jasmine Pena View
15-0084 United States Air Force Mr. Jeremy McCauley View
15-0085 Transport Corp. of America Mr. Greg Payne View
15-0021 United Parcal Service Mr. Samuel S. Elkind View
15-0054 Intrepid Coatings, Inc Mr. Robert D. Commisso View
15-0018 New Jersey State Funeral Directors Association, Inc. Mr. Guziejewski View
14-0193 CMC Mr. Michael Lesser View
15-0052 Seaboard Marine, LTD Mr. Omar Contreras View
15-0022 Mihama Corporation MS. Andrea Kornbluth View
15-0082 Schlumberger Technology Corporation Mr. Paul Lezak View
15-0032 Air Liquide (USA) LLC Mr. Jerry Freeman View
15-0110 Mace Tactical Solution, LLC Mr. Garnett Meador View
15-0108 W. J. Byrnes & Co Ms. Daisy Tate View
15-0086 HMT Associates, L.L.C. Mr. Andy Altemos View
15-0065 SOLARIS Mr. Keane Lao View
15-0080 Chemours Company FC, LLC Mr. Randolph Martin View
15-0053 Mr. Kevin Skerrett View
15-0015 FedEx Express Mr. Marvin Sudduth View
14-0238 Surface Deployment and distribution Command Mr. Marco Boasso View
15-0049 Thompson Tank, Inc. Mr. David Thompson View
14-0237 Textron Systems, Weapons & Sensor Systems Mr. James Baustert View
15-0071 Professional Emergency Resource Services (PERS) Mr. Rick Heylmun View
15-0091 Ammunition Surveillance Division Mr. James Gibson View
14-0157 Alaska Airlines Mr. Mike Tobin View
14-0235 Trinity Containers, LLC Mr. Greg McRae View
15-0076 The Lane Construction Corporation Ms. Michele Jacobs View