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49 CFR Parts 100-199

PHMSA has published several Frequently Asked Questions (FAQs) documents on programmatic topics. Please review these documents here at:

Additionally, OHMS has published Hazardous Materials FAQs based on letters of interpretation on the following topics:

OHMS: 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).

OPS: 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: 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.

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

Search the eCFR

Ref ID: Date Company Name Individual Name Response Document
00-0067 Air Freight Center, Inc. Mr. William Warder View
00-0068 Guidant Corporation Sam H. Lott, Ph.D. View
00-0069 Place Quick, Inc. Ms. Dianne Bechtold View
00-0071 Law Offices of Fisher & Douglas Ms. Rebecca A. Smith View
00-0073 Delta Analytical Corporation Mr. T. Jeff Jones View
00-0075 Innowave Incorporated Mr. Robert Haney View
00-0076 Berry Packaging of SC, Inc. Mr. Ron Stanley View
00-0077 Inkware Mr. John Tune View
00-0078 Administrators International Ms. Kelly D. Enright View
00-0079 Trinity Industries, Inc. Mr. Greg McRae View
00-0080 Eastman Chemical Company Ms. Julie Brown View
00-0081 HAZMATEAM, Inc. Mr. Leo Traverse View
00-0082 Yellow Freight System, Inc. Mr. Robert A. Maberry, III View
00-0083 Yellow Freight System, Inc. Mr. Robert A. Maberry III View
00-0085 Safecraft Fire Protection Systems Mr. Donald E. Warren View
00-0088 RIPA Mr. C.L. Pettit View
00-0090 Transport Workers Union of America Mr. Bruce W. Graska, Sr. View
00-0091 Rubbermaid Commercial Products, LLC Mr. Michael A. Roby View
00-0093 Rohm and Haas Company Mr. Laurent S. Vesier View
00-0095 Professional Services Industries Mr. Paul B. Medwig and Mr. Scott Bischoff View
00-0096 Huntsman Corporation Mr. Philip Abraham View
00-0097 P.B.&S. Chemical Company, Inc. Mr. Kevin Walker View
00-0099 Oakite Products, Inc. Mr. Barry L. Dance View
00-0100 Northrop Grumman Mr. David Norton View
00-0101 Mayer, Brown & Platt Mr. Philip R. Recht View
00-0102 Chemical Products Group Ms. Joyce Stratis View
00-0103 Safety & Compliance Associates, Inc. Mr. Mike Lopez View
00-0104 EnviroTech of America, Inc. Mr. Jeffrey A. Paiste View
00-0105 FMC Corporation Ms. Helen Hatch View
00-0107 Monsanto Company Mr. William J. Briner View
00-0108 Hazmateam, Inc. Mr. Paul J. Dambek View
00-0109 Mr. Todd Nash View
00-0110 Christenson Transportation, Inc. Mr. Barry McGowen View
00-0114 New Village Industrial Park Ms. Daniel G. Fox View
00-0115 Warner Norcross & Judd LLP Mr. Scott D. Hubbard View
00-0116 CBS News Mr. Huxley Galbraith View
00-0117 Aerostatic Engineering Mr. John Terry View
00-0118 Department of Energy Mr. Larry Blalock View
00-0119 Broward County Transit Ms. Sylvia M. Smith View
00-0121 Eveready Products Corporation Mr. Sam Vandivort View
00-0123 Keehn Service Corporation Mr. Richard C. Willard View
00-0124 Layne-Atlantic Mr. John Pittas View
00-0125 Reagent Chemical & Research, Inc. Mr. Robert Dritschel View
00-0128 Sure-Way Systems, Inc. Mr. Gary Chilcott View
00-0129 Dangerous Goods and Cargo Security Division William G. Wilkening View
00-0130 Dangerous Goods Program and Cargo Security William Wilkening View
00-0132 Dow Chemical Canada, Inc. Mr. Phil Stewart View
00-0133 Buck Research Instruments, LLC Mr. John Buetow View
00-0135 Shore Chemical Company Mr. John Shore, Jr. View
00-0136 HITECH Ms. Jackie Brian View

E.g., 02/09/2021
E.g., 02/09/2021
Part/Section Subject
171.7 Reference material
171.8 Definitions and abbreviations
171.9 Rules of construction
172.101 Purpose and use of hazardous materials table
172.101 Purpose and use of hazardous materials table
172.102 Special provisions
172.102 Special provisions
172.200 Applicability
172.201 Preparation and retention of shipping papers
172.202 Description of hazardous material on shipping papers
172.203 Additional description requirements
172.204 Shipper's certification
172.205 Hazardous waste manifest
172.3 Applicability
172.300 Applicability
172.301 General marking requirements for non-bulk packagings
172.302 General marking requirements for bulk packagings.
172.303 Prohibited marking
172.304 Marking requirements
172.310 Class 7 (radioactive) materials
172.312 Liquid hazardous materials in non-bulk packagings
172.313 Poisonous hazardous materials
172.315 Limited quantities
172.316 Packagings containing materials classed as ORM-D
172.322 Marine pollutants
172.323 Infectious substances
172.324 Hazardous substances in non-bulk packagings
172.325 Elevated temperature materials
172.326 Portable tanks
172.327 Petroleum sour crude oil in bulk packaging
172.328 Cargo tanks
172.330 Tank cars and multi-unit tank car tanks
172.331 Bulk packagings other than portable tanks, cargo tanks, tank cars and multi-unit tank car tanks
172.332 Identification number markings
172.334 Identification numbers; prohibited display
172.336 Identification numbers; special provisions
172.338 Replacement of identification numbers
172.400 General labeling requirements
172.400a Exceptions from labeling
172.401 Prohibited labeling
172.402 Additional labeling requirements
172.403 Class 7 (radioactive) material
172.405 Authorized label modifications
172.406 Placement of labels
172.407 Label specifications
172.411 EXPLOSIVE 1.1, 1.2, 1.3, 1.4, 1.5 and 1.6 labels, and EXPLOSIVE Subsidiary label
172.415 NON-FLAMMABLE GAS label
172.417 FLAMMABLE GAS label
172.419 FLAMMABLE LIQUID label