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.

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Interpretations Reference #

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Only Chief Counsel Responses

Ref ID:	Date Sort ascending	Company Name	Individual Name	Response Document
PI-71-070	07/29/1971	Anderson, Greenwood & Co.	G. Frank Bright	View
PI-71-069	07/28/1971	Hall, Tucker & Lovell	Wendell Hall, Jr.	View
PI-71-068	07/28/1971	ACF Industries, Inc.	R. M. Estes	View
PI-71-066	07/22/1971	Associated Corrosion Consultants Ltd.	H. M. Armstrong, P.E.	View
PI-71-065	07/14/1971	Florida Gas Company	Ray C. Colby	View
PI-71-062	07/13/1971	American Insurance Association	W. D. Malmstedt	View
PI-71-064	07/13/1971	Pioneer Natural Gas Company	J. W. Nanney	View
PI-71-0115	07/09/1971	Charles Wheatley Company	Mr. Del Moore	View
PI-71-061	07/08/1971	Shell Oil Company	R. L. Brown	View
PI-71-059	07/02/1971	Sellers & Sellers	Patricia Sellers	View
PI-71-0114	06/23/1971	Fluor Ocean Services, Inc	Mr. K.B. Lindsey	View
PI-71-058	06/17/1971	Anderson Greewood Company	Frank Bright	View
PI-71-0113	06/15/1971	Hawaii Public Utilities Commission	Mr. LeRoy Yuen	View
PI-71-0112	06/11/1971	Connecticut Public Utilities Commission	Mr. Robert H. Flanders	View
PI-71-0111	06/09/1971	Indiana Public Service Commission	Mr. D.J. Hendrickson	View
PI-71-057	06/04/1971	Memo: Internal		View
PI-71-056	06/04/1971	Philadelphia Electric Company	P. G. Mulligan	View
PI-71-0108	05/25/1971	Houston Natural Gas Corporation	Mr. Raymond R. Smith, P.E.	View
PI-71-054	05/05/1971	Conam Inspection, Inc.	J. Lee Ballard	View
PI-71-052	05/04/1971	Conam Inspection, Inc.	J. Lee Ballard	View
PI-71-0107	04/28/1971	Mr. Edward A. Declerck	Security National Bank Building	View
PI-71-0106	04/23/1971	Colonial Pipeline Company	Mr. M.U. Bagwell	View
PI-71-053	04/08/1971	Gray & Ductile Iron Founders	Charles F. Walton	View
PI-71-049	04/05/1971		Charles L. Smith	View
PI-71-050	04/05/1971	Calbom, Walker, Cox & Andrews	Mark F. Andrews, Jr.	View
PI-71-048	03/31/1971	Central Hudson Gas & Electric Corp	Charles A. Bolz	View
PI-71-047	03/31/1971	South Carolina Public Service Comm.	Mr. Ray M. Kightlinger	View
PI-71-046	03/30/1971	American Petroleum Institute	B. H. Lord	View
PI-71-044	03/29/1971	Heath Consultants Incorporated	Paul M. Heim	View
PI-71-043	03/25/1971	Indiana Public Service Commission	D. J. Hendrickson	View
PI-71-0105	03/24/1971	National Propane Corporation	Mr. Gerald Pohlman	View
PI-71-039	03/23/1971	El Paso Natural Gas Company	William F. Howard	View
PI-71-040	03/22/1971	Kansas Power and light Company	J. G. Williamson	View
PI-71-0104	03/18/1971	Office of the City Attorney	Mr. Lawrence E. Christenson	View
PI-71-036	03/16/1971		J. H. Lambdin	View
PI-71-035	03/11/1971	City of Palo Alto, Water-Gas Sewer Department	H. R. Remmel	View
PI-71-033	03/10/1971	Delta Gas Inc.	Gaylon Simmons	View
PI-71-034	03/10/1971	Branine, Ice, Turner& Ice	Arthur N. Turner	View
PI-71-0103	03/08/1971	Department of Housing & Urban Development	Mr. Robin H. Harbin	View
PI-71-029	03/05/1971	New Orleans Public Service, Inc.	Hugh M. Blain	View
PI-71-031	03/05/1971	South Jersey Gas Company	William F. Ryan	View
PI-71-030	03/05/1971		William H. Alexander	View
PI-71-026	02/24/1971	Indiana Public Service Commission	D. J. Hendrickson	View
PI-71-027	02/24/1971	National Propane Corporation	Gerald Pohlman	View
PI-71-025	02/22/1971	I.U.C. Gulf, Inc.	M. Cassaway	View
PI-71-024	02/22/1971	Williams Brothers Engineering Co.	Clinton McClure	View
PI-71-023	02/19/1971	Central Telephone & Utilities Corp	W. E. Mickelson	View
PI-71-0101	02/18/1971	Natural Gas Distributing Co	Mr. John G. Wilson	View
PI-71-0102	02/18/1971	Public Service Commission	Mr. T. K. Spalding	View
PI-71-016	02/09/1971	Treasurer's Office State of Fla.	S. Stapleton	View

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Letters of Interpretation