Massachusetts State Police — Hazardous Materials Safety Interpretation

Page 1U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration 1200 New Jersey Avenue, SE Washington, DC 20590 September 28, 2021 Trooper Scott Maguire Massachusetts State Police 906 Elm Street Concord, MA 01742 Reference No. 21-0060 Dear Mr. Maguire: This letter is in response to your May 25, 2021, email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to portable tanks and cargo tanks. We have paraphrased and answered your questions as follows: Q1. You ask whether it is permissible to weld a specification Department of Transportation (DOT) 51 portable tank to a chassis and convert it to a cargo tank motor vehicle (CTMV) for the transportation of liquefied petroleum gas (LPG). A1. The answer is no. The definition of a “cargo tank” as specified in § 171.8 of the HMR does not authorize a bulk packaging that is fabricated to the specification of a portable tank. Additionally, the HMR defines a CTMV as a “motor vehicle with one or more cargo tanks permanently attached to or forming an integral part of the motor vehicle.” Therefore, a DOT 51 portable tank which has been permanently attached to a motor vehicle would not constitute a CTMV as the tank is not an integral part of the motor vehicle. Q2. You ask whether a specification DOT 51 portable tank retains its specification after being permanently attached to a vehicle. A2. The answer is no. The portable tank as described in your inquiry was originally fabricated as a specification DOT 51 portable tank. However, once the specification DOT 51 portable tank was permanently attached to the motor vehicle, it no longer meets the definition of a “portable tank” as defined in § 171.8. Therefore, the specification DOT 51 portable tank loses its specification because it can no longer be defined as a “portable tank.” See Answer A1.#

Page 2Q3. You ask whether § 173.32(a)(3) applies to both specification and non-specification portable tanks. A3. The answer is yes. The use of portable tank requirements in § 173.32(a)(3) can apply to both specification and non-specification portable tanks. I hope this information is helpful. Please contact us if we can be of further assistance. Sincerely, T. Glenn Foster Chief, Regulatory Review and Reinvention Branch Standards and Rulemaking Division#

Page 3Andrews 21-0060 From: INFOCNTR (PHMSA) To: Dodd, Alice (PHMSA) Cc: Hazmat Interps Subject: FW: Letter of Interpretation Date: Thursday, May 27, 2021 4:32:04 PM Attachments: PT Interp Request.docx Hi Alice, Please see the attached LOI request. Below, is the mailing address and phone number for the inquirer. Please let me know if you need anything else. Regards, -Breanna --------------------------------------------- Scott Maguire PO Box 9 Millbury, MA 01527-0009 508.259.0875 From: Maguire, Scott (POL) [mailto:scott.maguire@state.ma.us] Sent: Tuesday, May 25, 2021 3:10 PM To: INFOCNTR (PHMSA) <INFOCNTR.INFOCNTR@dot.gov> Subject: Letter of Interpretation CAUTION: This email originated from outside of the Department of Transportation (DOT). Do not click on links or open attachments unless you recognize the sender and know the content is safe.#