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Section §172.504: General placarding requirements

Below are the available interpretations and guidance for the given section. To return to the list of parts, use the Parts link above. If you do not see any guidance or interpretation information below, that means there is none available for the given part/section. Return to the search page to browse additional regulations sections.

PHMSA has published several Frequently Asked Questions (FAQ) documents on regulatory topics. Please review our FAQ documents below:

Additionally PHMSA has Hazardous Materials FAQs based on letters of interpretation on the following topics:

This section of the website provides the ability to find regulations information including regulations parts, content of sections, and interpretations for regulations sections. Below is a list of parts, identified by the part number and subject. 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.

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.

The regulations text of the section can be found on the eCFR website. To view the regulations text, use the link below. For assistance, please send an email to

View section 172.504 on the ECFR website

Interpretation Responses

Ref ID Date Company Name Individual Name Response Document
22-0139 WM Pacific Northwest Haydon Morris View
22-0050 Mayo Clinic Mr. Travis Brandt View
22-0086 Fujitrans USA Inc. Laura Warren View
16-0166R Haliburton HRD Albert R. Vandeaver View
22-0015 ICE Service Group & SPS Packaging Systems Kurt Colborn View
22-0017 Old Bridge Chemicals, Madison Industries, Inc. Sandy Volk View
21-0099 Lithium Battery Service GbR Eva Glimsche View
19-0116 Robert Lewis View
20-0025 Entergy Donnie James View
20-0022 Railsback HazMat Safety Professionals LLC Rex Railsback View
20-0003 Texas Department of Public Safety Corporal Casey Jones View
20-0019 National Motor Freight Traffic Association, Inc. Lisa O'Donnell View
19-0124 Dru Chem Inc. Bill Krause View
19-0020 Zee Company Ricky Pruitt View
18-0075 MH Group, LLC Paul Perez View
18-0094 DG Advisor, LLC Ben Barrett View
18-0077 ICL-IP America, Inc Levi Howell View
18-0079 Roberts Oxygen Company, Inc. Robert McHale View
13-0052R Simpson Strong Tie Company, Inc. Densie Nguyen View
17-0109 Hunting Titan, Inc Joe Murphy View
17-0068 Duke Energery Corporation Mr. Charles Denny View
10-0254 Department of California Highway Patrol Captain Steve Dowling View
99-0048 Georgia Public Service Commission Captain Bruce Bugg View
05-0168 Department of the Army Mr. Charles R. Schulz View
05-0158 Georgia Gulf Sulfur Mr. Jerry J. Jennett View
11-0035 Department of the Army Mr. Daniel A. Maham View
08-0049 Los Alamos National Laboratory Ms. Lorelei Johnson View
03-0122 Century International Arms, Inc. Mr. Gary A. Beagle View
07-0171 4th ID-Fort Carson G3/IMT Mr. Len Hammond View
06-0082 3AL Testing Corporation Mr. Robert Fick View
99-0307 Michels Pipeline Construction, Inc. Mr. Rod Day View
01-0300 Alaska Abatement Corporation Mr. Arthur Solvang View
98-0504 Minnesota Department of Transportation Mr. Michael Ritchie View
05-0311 MHF Logistical Solutions Mr. Kurt Colburn View
07-0124 Taylor Express, Inc. Mr. Roderick MacLean View
01-0212 Office of Motor Carrier Services Mr. Michael Ritchie View
99-0205 R & L Transfer, Inc. Mr. Randy Russell View
98-0506 Minnesota Department of Transportation Mr. Michael Ritchie View
11-0102 Texas Department of Public Safety Texas Highway Patrol/Commercial Vehicle Enforcement Mr. Patrick B. Zatopek View
11-0171 Reynolds Transport Mr. Aaron Carr View
15-0034 Crowley Liner Service Mr. Michael Lesser View
00-0284 Calvert Cliffs Nuclear Power Plant Mr. Charles H. Cruse View
13-0052 Simpson Strong Tie Company, Inc. Ms. Denise Nguyen View
02-0205 California International Chemical Co., Inc. Karen Lowell,Esq. View
14-0031 YRC Freight, Inc. Ms. Susan D. Camara View
14-0102 Brighter Horizons Environmental Inc. Mr. John Nelson View
00-0323 Iowa Department of Transportation Mr. Tom Sever View
05-0312 Wiley Rein & Fielding LLP Mr. George A. Kerchner View
07-0230 Pipe Recovery Systems, Inc. Mr. Michel Chammas View
15-0052 Seaboard Marine, LTD Mr. Omar Contreras View
11-0182 Mr. Henry Wake Huffman View
99-0145 PWN Environmental Mr. Bradford A. Gagnon View
05-0252 Uwchalan Township Police Department CPL F. Allen Mauger, Jr. View
14-0173 Sika Corporation USA Mr. Arthur Van Houten View
06-0271 Georgia Department of Public Safety Captain Bruce Bugg View
00-0195 AGWORKS, Inc Ms. Esmeralda Garcia View
07-0081 Pilot Chemical Company Mr. Matthew J. Leary View
14-0183 Denton Police Department Mr. William Burson View
12-0094 Big Creek Media Mr. Nelson Lemmond View
99-0169 Ultramar Diamond Shamrock Mr. George Lewis View
08-0038 Materials Handling Group, Inc. Mr. Jeffrey M. Welsh View
14-0198 Denton Police Department Mr. Wm. Scott Burson View
04-0052 Dane County Risk Management Mr. Mark Finarty View
09-0168 Baker Hughes Mr. Aubrey R. Campbell View
16-0166 Halliburton Mr. Albert Vandeaver View
08-0285 North Carolina State Highway Patrol Trooper C. R. King View
11-0011 Sunny Point Military Ocean Terminal - DSN 488 Ms. Lonnie Burks View
06-0143 Georgia Department of Public Safety Captain Bruce Bugg  View
02-0089 Honeywell International, Inc. Barbara Konrad View
02-0043 R+L Carriers Dana Probasco View
09-0171 Carus Corporation Mr. Chithambarathanu Pillai View
16-0177 Robinson Nevada Mining Company Mr. Matt Thompson View
09-0234 Donaldson Company Mr. Tom Zweber View
13-0086 Texkota Transit, LLC Mr. HC Brown View
07-0063 U.S. Coast Guard Sector Juneau Lieutenant Rob Nakama View
13-0025 Shore Side Safety and Hazardous Material Reviews Mr. Michael Lesser View
02-0279 Bay Zinc Company, Inc Jennifer Clemenson View
13-0026 FedEx Freight, Inc. Mr. Mike Brust, CDS View
02-0245 Mutual Liquid Gas & Equipment Co., Inc. Ron Stover View
04-0260 J & R Brokerage, Inc. Mr. John F. Martin View
09-0133R Total Energy Jennifer D. Janelle, Esq. View
05-0108 Commonwealth of Virginia Sergeant David Feathe View
15-0024 Hazardous Materials Response Unit Officer Daniel Voelker View
12-0066 C & W Global Mr. Jeff Bailey View
05-0043 Allied Universal Corporation Ms. Robin J. Eddy Bolte View
12-0085 Brothers Group, Inc. Mr. Kenneth Kelton View
08-0098 HazMat Resources, Inc. Mr. Danny Shelton View
16-0039 GEO Dynamics Inc. Mr. Brett Lehman View
14-0239 Sun Chemical Corporation Ms. Amy fischesser View
11-0053 Department of the Army Mr. Joseph Dugan View
10-0032 Energy Solutions Mr. James H. Portsmouth View
11-0066 Boyle Transportation Mr. Rick Araniz View
09-0077 Crown Technology, Inc. Mr. Jeff Buckner View
07-0120 The Fertilizer Institute Ms. Pam Guffain  View
11-0076 Con-way Freight Mr. Keith Jesse Powell View
16-0054 Infotrac, Inc. Mr. Jason Kob View
99-0193 Mr. Gerald L. Blase View
06-0004 Department of the Air Force TSgt. Jesse Rubalcaba View
05-0309 AMCOM, U.S. Army Garrison Mr. Richard E. Eads View
07-0074 Veolia Environmental Services Ms. Jennifer Eberle View
09-0055 MCSAP, Troop I, Olathe Mr. Rex Railsback View
11-0107 Chammas Cutter, Inc. Mr. Michael Chammas View
07-0102 Medical Services of America Mr. Wayne R. Cromley View
14-0231 PPG- Comex Mr. Israel Villarello View
09-0120 Fleet Safety Services, Inc Mr. Gary LaBreck View
01-0209 Applied Specialties, Inc. Ms. Adrainne B. Scheurman View
01-0273 Mr. T.L. Nebrich Mr. T.L. Nebrich View
05-0189 NASA-White Sands Test Facility Mr. Paul Goodwin View