ABC Nitrogen Service Corp — Hazardous Materials Safety Interpretation

Page 1U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration 1200 New Jersey Avenue, SE Washington, DC 20590 March 27, 2024 Aimee Fontenot DOT Coordinator ABC Nitrogen Service Corp 11425 I-10 East Baytown, TX 77523 Reference No. 24-0007 Dear Ms. Fontenot: This letter is in response to your January 26, 2024, email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to placarding requirements for transportation of nitrogen, refrigerated liquid (cryogenic liquid). You state that your company transports nitrogen in insulated cargo tanks designed and constructed so that the pressure in such packagings will not exceed 25.3 psig under ambient temperature conditions during transportation in accordance with § 173.320(a). It is your understanding that this transportation is excepted from certain requirements of the HMR. Specifically, you ask whether hazard placards are required on insulated cargo tanks that transport “UN1977, Nitrogen, refrigerated liquid cryogenic liquid, 2.2” in this manner. The answer is no. Placards are not required on the insulated cargo tanks used for carriage of “UN1977, Nitrogen, refrigerated liquid cryogenic liquid, 2.2” when transported in accordance with the conditions of § 173.320(a). The exceptions contained in § 173.320 are applicable to the transportation by motor vehicle and railcar of “atmospheric gases” such as nitrogen—see § 171.8—and helium, cryogenic liquids, in select packagings, including insulated cargo tanks, designed and constructed so that the pressure in such packagings will not exceed 25.3 psig under ambient temperature conditions during transportation. This includes exception from the Part 172, Supbart F placarding requirements of the HMR. I hope you find this information helpful. Please contact us if we can be of further assistance. Sincerely, Dirk Der Kinderen Chief, Standards Development Branch Standards and Rulemaking Division#

Page 2Roundtree 24-0007 From: Roundtree, Taurean (PHMSA) To: Dodd, Alice (PHMSA) Cc: DerKinderen, Dirk (PHMSA) Subject: FW: 173.320 - LOI request Date: Friday, February 2, 2024 11:26:10 AM Attachments: image002.png Good morning Alice, This email came in last week and we attempted to answer via phone/email with a previously issued letter, but the requestor would like a letter that is addressed to their company. The original request is at the bottom of this message, and I am including her contact information as well. I have spoken Dirk we have agreed to draft a letter, could you please enter the request into FileMaker and assign it to me. Requestor title and contact info: Aimee Fontenot DOT Coordinator ABC Nitrogen Service Corp 11425 I-10 East Baytown, Texas 77523 832-790-9279 Thank you, Taurean Roundtree Transportation Specialist United States Department of Transportation Pipeline and Hazardous Materials Safety Administration (771) 216-4118 (cell) From: Cardez, Eugenio (PHMSA) <Eugenio.cardez@dot.gov> Sent: Friday, January 26, 2024 12:58 PM To: Roundtree, Taurean (PHMSA) <Taurean.Roundtree@dot.gov> Cc: DerKinderen, Dirk (PHMSA) <Dirk.DerKinderen@dot.gov>; Nickels, Matthew (PHMSA) <Matthew.Nickels@dot.gov> Subject: FW: 173.320 Hey Taurean, Would you mind taking an initial try with this one and see if we can maybe handle by phone. If they#

Page 3still want to request a letter we’ll move it to Alice for formal processing. We can have a chat before you reaching out to them and go over your findings if you’d like. Thanks, Eugenio From: Raynor, T'Mia (PHMSA) <t'mia.raynor@dot.gov> Sent: Friday, January 26, 2024 12:21 PM To: Hazmat Interps <hazmatinterps@dot.gov> Subject: FW: 173.320 Good Afternoon, Would someone from the team be able to assist the user below? Thanks, T’Mia Raynor Webmaster, Office of the PHMSA CIO US Department of Transportation Pipeline and Hazardous Materials Safety Administration 1200 New Jersey Ave. SE, Washington, D.C., 20590 Office: 202.366.9818 ◊ Mobile: 202.580.9447 PHMSA Home | LinkedIn | Twitter | HAZMAT | OPS From: Aimee Fontenot <aimee@abcnitrogen.net> Sent: Friday, January 26, 2024 12:20 PM To: PHMSA Website Manager <PHMSAWebsiteManager@dot.gov> Subject: 173.320 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. Good Morning, I write you today with a formal request for a formal letter of interpretation regarding the applicability of the cryogenic exemption under section 173.320 for placarding purposes. Our organization transports Nitrogen in insulated cargo tankers that are designed and constructed so that the pressure will not exceed 25.3 psig under ambient temperature conditions during transportation. We seemed to be challenged on the exemption by police#

Page 4and Dot officers on the road about not having a Hazmat Placard. Can you please give me a formal interpretation of the exemption as it pertains to transporting N2 by tanker stating if or if not required to have a hazmat placard, or any placard other than the UN 1977. Thank you in advance for your time and consideration. Aimee Fontenot ABC Nitrogen 832-790-7979#