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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
06-0040 Marquis Spas Mr. Gary Kertz View
05-0193 MGA Research Corporation Mr. Anthony J. Angello View
06-0035 Supervac 2000, Inc. Ms. Nathalie Doyon View
06-0135 Los Alamos National Laboratory Packaging and Transportation Mr. Joseph Lowery  View
06-0136 Samax Enterprises Mr. Perry J. Patton View
06-0114 Musket Corporation Mr. Doug Lumry  View
06-0097 Ms. Kristen Taddonio  View
06-0142 Associated Spring Raymond Mr. Thomas J. Fischer View
05-0075 SJC Compliance Education, Inc. Mr. Stephen Cansler View
06-0027 Mr. Steve Kranyec View
06-0071 Rieke Packaging Systems Mr. Gary Baughman View
06-0128 Mr. Richard B. Loden View
06-0105 Volvo Aero Services (Seattle) LLC Mr. Ronnie Hamblin View
05-0283 Transportation Development Group Mr. Jim Powell View
06-0002 MHF Logistical Solutions Mr. Kurt Colborn View
06-0002 MHF Logistical Solutions Mr. Kurt Colborn View
06-0082 3AL Testing Corporation Mr. Robert Fick View
06-0133 Global Fire and Safety, Inc. Mr. Bill McDonald  View
06-0072 HB Fuller Company Mr. Eugene J. Secor View
06-0103 Law Offices of Michael J. Pangia, P.C. Mr. Michael J. Pangia View
06-0134 Special Materials Company Mr. Adam Feldman View
04-0097 U. S. Army Corps of Engineers Marcia C. Davies, Ph.D. View
06-0003 Thompson & Simmons, PLLC Mr. Charles T. Simmons View
06-0132 Motor Carrier Compliance & Safety Co Mr. Jay Muratore View
05-0309 AMCOM, U.S. Army Garrison Mr. Richard E. Eads View
06-0115 Waste Technology Services, Inc. Ted L. Nebrich, Jr., CHMM, QEP, REM  View
06-0022 U.S. Coast Guard CITAT Mr. Steven T. Webb View
06-0130 A Duie Pyle Companies Mr. Richard D. Kaczynski View
06-0063 Logistical Solutions Mr. Kurt Colborn View
06-0090 Target Specialty Products Mr. Gary Maxwell View
06-0007 Medical Waste Solutions, Inc. Mr. Russell A. Karlins View
06-0116 Utah Highway Patrol Vehicle Safety Section Mr. Bradley W. Clayton View
06-0119 Ontech Delaware, Inc. Michael S. Slocum, Ph.D.  View
06-0073 Netjets, Inc. Mr. D. Richard Meikle View
06-0089 Global EnviroServices Corp. Mr. Kevin J. Swinden View
05-0247 Vanderbilt Chemical Corporation Mr. Joe Curtis View
06-0084 RWE NUKEM Corporation Mr. Stan Hodges View
05-0182 Daniels Sharpsmart, Inc. Mr. Terry Grimmond View
05-0205 Gallagher & Kennedy Mr. Chris S. Leason View
06-0075 West Marine Products, Inc. Mr. Todd A. Nash View
06-0080 DG Supplies, Inc. Mr. Michael Bowen  View
06-0088 Jacksonville Port Authority Mr. Michael Becker View
06-0110 Computer Sciences Corporation Mr. James R. "Hank" Ellis  View
06-0093 Mr. Bill Korzeniowski  View
05-0088 Thunderbird Cylinder, Inc. Mr. Fred A. Nachrnan View
06-0059 Seaboard Marine, Ltd. Mr. John P. Plasencia View
05-0149 Swingless Golf Club Mr. Jim DePorche View
06-0058 Ferreilgas Mr. Ross Warnell View
06-0118 Manager, Technical Services - Aerosol Mr. Matthew D. Kuehn  View
06-0101 Buckeye Fire Equipment Company Mr. John Classic  View