# Hazardous Materials Safety Interpretation 02-0071 **Citation:** 02-0071 **Type / status:** guidance / guidance **Agency:** Pipeline and Hazardous Materials Safety Administration **Effective:** Not stated **Published:** 2002-10-22 02-0071 concerning 174.67. ## Document text <<>> Washington, D.C. 400 Seventh Street, S.W. 20590 Research and Administration Special Programs OCT 2 2 2002 Ms. Sarah R. Maguffee Husch & Eppenberger, LLC Ref. No. 02-0071 235 East High Street P.O. Box 1251 Jefferson City, MO 65102-1251 Dear Ms. Maguftee: This responds to your February 27, 2002 letter concerning attendance requirements for rail car unloading under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180). Specifically, you ask if the attendance requirements apply to a tank car undergoing a steaming process that is not manway open, provided the steaming process is not connected to or part of the unloading process. The February 18, 2000 letter addresses the rail car attendance requirements as they apply to a steaming process during which vapors are vented through a valve that is connected via closed pipe to a permitted air pollution control device. In addition, on November 15, 2001, we issued a letter of clarification to Koch Materials Company (Ref. No. 01-0269) concerning attendance requirements for a steaming process that is conducted with the manway slightly open to relieve any potential pressure. Both letters stated that attendance is not required when a tank car is connected to a steaming device that is not interconnected with or part of the unloading process or if the steaming process is conducted with all valves and manways closed. This statement apparently has resulted in some confusion as to the applicability of the attendance requirements to certain steaming operations. we erroneously affirmed with an interpretation that would allow a tank car, undergoing a steaming we are withdrawing ietter kel. No. 01-0269, which we issued on November 15, 2001. In that letter process before unloading, to have an open manway without being attended. We apologize for the error and subsequent confusion this may have caused. The attendance requirements set forth in § 174.67(i) apply to a steaming operation that is connected to or part of the unloading process. Further, the attendance requirements apply when manways or valves are open to relieve pressure, either to the atmosphere or a pollution control device, during heating of a material in preparation for unloading, even if the steaming process is not connected to or part of the unloading process itself. Thus, the steaming process you describe is subject to the attendance requirements in § 174.67(i). 114.61 020071 <<>> Page 2 I hope this information is helpful. If you have further questions, please do not hesitate to contact this office. Sincerely, Helmand 7. Mazallo Edward Mazzullo Director, Office of Hazardous Materials Standards <<>> FEB. 27.2002 1:59PM HUSCH & EPPENBERGER NO, 1899 P. 2 : Husch & Eppenberger, LIC 235 East High Street Attorneys and counselors at Law P.O. Box 1251 573,635.9119 Jeffarson City. MO 65102-1251 573.634,7854 f0X E-mail: sarah.maguffee@husch.com Direct Dial: (573) 761-1111 February 27, 2002 volinser 3 74.67 Via Facsimile and U.S. Mail Tank Car Unloading Thomas G. Allan Senior Transportation Regulations Specialist 02-0011 Office of Hazardous Materials Standards (DHM-10) Research and Special Programs Administration U.S. Department of Transportation 400 Seventh Street, S.W. Washington, D.C. 20590 Re: Request for Interpretation Regarding Tank Car Unloading Dear Mr. Allan: On February 18, 2000, your office issued a clarification of the attendance requirements for tank car unloading in 49 C.F.R. 174.67. The clarification (copy enclosed) addresses applica-. tion of the attendance requirements to a tank car steaming process. We represent a company that receives hazardous materials by tank car. Prior to initiation of the unloading process, certain indicates that the attendance requirements in 49 C.F.R. 174.67 do not apply to the tank cars while tank cars delivered to the company undergo a steaming process. The February 2000 clarification they are undergoing the steaming process used by our client. We respectfully request confirma- tion of our understanding that 49 C.F.R. 174.67, as clarified by the February 2000 letter, does not apply to tank cars during the steaming process described below. car. The coil is not in contact with the product in the tank car, and the steam hose is the only process, which precedes unloading, a steam hose is attached to a coil on the interior of the tank way cover on the top of the tank car is slightly ajar to prevent potential pressure buildup in the tank car. We do not believe that the attendance requirements in 49 C.F.R. 174.67 apply to this standing. :ODMAIPCDOCSUEFFERSON_CITY113939011 SPRINGFIELO ST. LOUIS LEAWOOD CLAYTON WIGHITA KANSAŞ ÇITY PEORIA JEFFERSON CITY CHATTANOOGA <<>> FEB. 27.2002 1:59PM HUSCH & EPPENBERGER NO. 1899 P. 3 Thomas G. Allan Senior Transportation Regulations Specialist February 27, 2002 Page 2 Section 174.67 states, in relevant part: (i) Tank cars may not be allowed to stand with unloading connections attached after unloading is completed. car is connected to [the unloading device, the car must be Throughout the entire period of unloading, and while [the] G) If necessary to discontinue unloading a tank car for any reason, all unloading connections must be discon- nected. All valves must first be tightly closed, and the closures of all other openings securely applied and the tank car is not connected to any unloading device. The only physical connection be- During the steaming process described above, ho unloading connection is established, tween the tank car and the plant is the steam hose, which is not in contact with the product and is not considered an unloading connection or device. All valves on the tank car that are used to standing that the attendance requirements in Sections 174.67(i) and (i) do not apply. offload the product remain closed during steaming. Under these circumstances, it is our under- The clarification issued in February 2000 supports our understanding. The clarification states that attendance is not required when a tank car is connected to a steaming device that is not interconnected with, or part of, the unloading process.. The steam hose used by our client is not interconnected with, or part of, the unloading process. Under the February 2000 clarification; the attendance requirements do not apply during our client's steaming process, therefore. dance requirements in 49 C.F.R. 174.67. If you have any questions about this request or require We would appreciate your prompt response to this request for clarification of the atten- additional information, please contact me. Thank you for your assistance in this matter. Sincerely, • Sarah R. Maguffee Sarah R. Maguffee Enclosure cc: Laurel S. Burchell, w/enclosure Christine Zavada, w/enclosure :ODMAIPCDOCSUEFFERSON_CTTY113939012 HUSCH EPPENDERGER, LUC ## Provenance - Official: Yes - Source: - Source ID: `phmsa` - SHA-256: `a0bc9336aea8f948ea913e3d997d3e5bac294d5c51785d25c39164633cf125f5` - Retrieved: 2026-08-20T00:59:31.977Z - Exported: 2026-08-23T17:25:30.060Z - Document slug: `phmsa-interpretation-02-0071` ### Source metadata ```json { "materialSubtype": "interpretation", "interpretationArea": "hazardous_materials", "representation": "full_text_from_official_pdf", "companies": [], "individuals": [], "refIds": [ "02-0071" ], "catalogDates": [ "2002-10-22" ], "catalogParts": [ 174 ], "catalogRowCount": 1, "sourceRecordUrls": [ "https://www.phmsa.dot.gov/node/59201" ], "linkedAttachmentUrls": [], "unavailableResponseUrls": [], "duplicateRepresentationUrls": [], "citedSections": [ "174.67", "174.67(i)" ], "catalogPageUrls": [ "https://www.phmsa.dot.gov/regulations/title49/section/17467" ], "pdfUrls": [ "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2002/020071.pdf" ], "representations": [ { "viewUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2002/020071.pdf", "detailUrl": null, "detailHtmlPath": null, "pdfUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2002/020071.pdf", "pdfArtifactPath": "data/sources/phmsa-interpretations/02-0071-6ef150a383.pdf", "pdfArtifactSha256": "b1ebebd36cc4069fd15d251fbf138a363713deee037d02d8e4404be4e9037bba", "extractedTextPath": "data/sources/phmsa-interpretations/02-0071-6ef150a383.v2.txt", "extractedTextSha256": "9523e9fa3229ae479bb6615d0ff1ba4585bebd8641c9e05baee1e02b712c135f", "pageCount": 4, "extractionVersion": 2 } ], "caveat": "Interpretations apply regulations to the facts presented and do not create independently enforceable requirements.", "jurisdiction": "US" } ```