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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
13-0160 The Boeing Company Mr. Paul Burroughs View
13-0148 NACA Logistics (USA), Inc. Mr. Eric Fischer View
13-0137 Western Sales and Testing, Inc. Mr. Mark Griffin View
13-0188 Legend, Inc. Mr. Don Collier View
13-0163 Green Bay Packaging Inc. – Fremont Divisio Mr. Lance Lycourt View
13-01637 National Association of Chemical Distributors Ms. Jennifer Gibson View
13-0150 Fowler Transportation Ltd. Mr. Kevin Riley View
13-0197 Bemis Company, Inc. Mr. Andrew Petersen View
13-0187 Westpak, Inc. Mr. Pal Khangaldy View
PI-13-0006 Ms. Shelley Ragsdale View
13-0196 Select Sire Power, Inc. Mr. Mark Carpenter View
13-0205 Reid laboratories LLC Mr. Scott Hopkins View
13-0176 HSB Global Standards Mr. Oberst Mulet View
13-0180 Mr. Tom Alexander View
13-0172 Attorney at Law Mr. Lawrence W. Bierlein View
13-0035 Con-Way Truckload Mr. Jeff Messer View
11-0274R Department of the Army Ms. Sarah Gedrich View
13-0143 Mr. Joe Calonge View
13-0129 Lockheed Martin Corporation Ms. Mary P. Morningstar View
13-0084 Chevron Products Company - Chevron Salt Lake Refinery Mr. Denton L. Schantz View
13-0159 Albermarle Corporation Mr. Brad Thomas View
13-0168 Sandler, Travis & Rosenberg, P.A. Mr. Mark Ludwikowski View
13-0184 Coda Energy Mr. Chris Aragon View
13-0173 KIK Custom Products - Classic Division Ms. Stacey Gorka View
13-0182 LabelMaster Services Mr. Robert Richard View
PI-13-0004 Colorado Springs Utilities Mr. Mason Parsaye View
13-0170 ASARCO Grupo Mexico Mr William Loehr View
13-0175 Sigma-Aldrich Ms. Leigh Davidson View
13-0169 SC Johnson & Son, Inc Ms. Georgia Barr View
13-0141 Skolnik Industries Mr. Alexander Skolnik View
13-0147 Hazmat Resources, Inc. Mr. Danny Shelton View
13-0133 Tytal Mr. Ing Fernando Giaza View
13-0179 PTP Consulting, Inc Carol Brozosky, CHMM, CET View
13-0162 Deere & Company WW Supply Management Compliance Mr. Mike Moetsch View
13-0114 WTS, Inc. Mr. James Moulds View
13-0152 Remcon Plasticcs Incorporated Mr. Peter J. Connors View
13-0161 Royal Oak Enterprises LLC Mr. Phillip Zimmerman View
13-0174 Scopelitis, Garvin, Light, Hanson & Feary, P.C. Mr. Brandon K. Wiseman View
13-0165 Con-Way Truckload Mr. Jeff Messer View
13-0131 Mr. Tim McLoughlin M & M Metrology, Inc. View
13-0116 Custom Metalcraft, Inc Mr. Eric Larson View
13-0118 Mr. Ed Mazzullo View
13-0055 Health, Environment, and Safety Arkema Ms. Christina Kurtz View
13-0155 Akzo Nobel Chemicals, Inc. Mr. Mark Connolly View
13-0177 CHART-SeQual Technologies, Inc. Mr. Neal Maloy View
13-0120 Western International, Inc. Mr. David Ebbers P.E. View
13-0156 Matthews Associates, Inc Mr. George Foucher View
13-0128 Linde Gas North America LLC Mr. Guy Dalton View
13-0119 Kurt J. Lesker Company Mr. Lew Miller View
13-0144 Mr. Lucien DiMeo View