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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
13-0064 HMT Associates, L.L.C. Mr. E.A. Altemos View
13-0050 Chevron Phillips Chemical Company LP Mr. Jonathan VanScoyoc View
13-0079 Texas Department of Public Safety – CVE Sergeant Patrick Zatopek View
13-0059 BEAM Strategic Solutions Mr. Mark F. Kozak View
13-0018 Association of American Railroads Mr. Matthew Forister View
13-0019 G2 Revolution LLC Mr. Troy Erickson View
13-0032 Complete Cylinder Service, Inc. Mr. Paul Kleier, Jr. View
12-0247 Curtis Bay Energy Mr. Edward Petrullo View
13-0042 City Machine and Welding, Inc. Mr. Kent Carroll View
12-0249 Praxair Distribution, Inc. Mr. David B. Sonnermann View
12-0228 TGO Technologies, Inc. Mr. Rudolph S. Caparros View
13-0075 Western International Gas & Cylinders Dr. Wesley D. Scott View
13-0060 International Radiation Safety Consulting, Inc. Mr. Timothy Brandon View
13-0020 Cytec Industries, Inc. Mr. Dwayne McNally View
13-0047 Navarro Research and Engineering, Inc. Mr. David Wilson View
13-0086 Texkota Transit, LLC Mr. HC Brown View
13-0037 Public Utilities Commission of Ohio Transportation Department Mr. Tom Forbes View
13-0041 Carry and Clean, LLC Mr. H. Michael Lord View
13-0069 Go Glow Placard Mr. Patrick D. Nimtz View
13-0053 OBO/CFSM/FAC/PS, Ms. Heidi I. Barranco-Fisher View
12-0267 Allied Universal Corporation Ms. Robin Bolte View
13-0044 N & M Transfer Co., Inc. Mr. Cary Krickeberg View
13-0048 City of Burbank, Public Works Department Mr. Ferris Kawar View
13-0002 UPS Mr. Samuel S. Elkind View
12-0225 General Electric Capital Corporation Mr. John Byrne View
12-0225 General Electric Capital Corporation Mr. John Byrne View
13-0010 Inmark Packaging Mr. Jay Johnson  View
13-0052 Simpson Strong Tie Company, Inc. Ms. Denise Nguyen View
13-0025 Shore Side Safety and Hazardous Material Reviews Mr. Michael Lesser View
13-0033 Dangerous Good of America    Mr. Fred A Romero View
13-0054 TOM DOLCE Training Associates Mr. Thomas Dolce View
13-0013 Global Products and Services, Baker Hughes Mr. Aubrey R. Campbell View
13-0038 Monsanto Company Mr. David Peters View
13-0056 UPS Mr. Matthew Maslanka View
13-0017 Inmark Packaging Mr. Jay Johnson View
13-0057 Ameresco Mr. Johnny Rogers View
13-0011 URS Corporation Mr. Andrew N. Romach View
13-0001 Aris Electronics Mr. Avraham Rahimi View
06-0123R Dangerous Goods Advisory Council Mr. Frits Wybenga View
13-0030 3737 Miller Park Drive Mr. Harold DePriest View
13-0031 Minigrip Mr. Ben Hellming View
13-0028 JAL Cargo Service Co., Ltd. Mr. Kenta Kuronuma View
13-0043 Deere & Company WW Supply Management Compliance Mr. Mike Moetsch View
05-0015R Manager Regulatory Compliance Ms. Rebecca L. Cernick View
13-0027 FedEx Freight, Inc. Mr. Mike Brust View
12-0013R GeoDynamics Mr. Rick Chewning View
12-0231 SIEMENS Industry, Inc. Mr. Damien Belot View
12-0243 New York State Department of Environmental Conservation Alan G. Woodard, Ph.D. View
13-0003 Air Liquide USA LLC Mr. Jerry W. Freeman View
13-0026 FedEx Freight, Inc. Mr. Mike Brust, CDS View