O.D.O.T. Commerce and Compliance Division — Hazardous Materials Safety Interpretation

Page 11200 New Jersey Avenue, SE Washington, DC 20590 U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration April 2, 2026 Mr. Andrew Zikmund Compliance Specialist O.D.O.T. Commerce and Compliance Division 5920 Highway 30 Huntington, OR 97907 Reference No. 26-0026 Dear Ms. Zikmund: This letter is in response to your February 17, 2026 email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the shipping paper and marking requirements of non-odorized liquefied petroleum gas (LPG). We have paraphrased and answered your questions as follows: Q1. Does the requirement in § 172.203(p) to enter the word “non-odorized” or “not-odorized” on a shipping paper apply to non-odorized shipments of “UN1011, Butane,” “UN1978, Propane,” and “UN1077, Propylene”? A1. Yes. LPG includes gases composed predominantly of the following either by themselves or as mixtures: butane, isobutane, propane, propylene (propene), butylenes (butenes).1 Section 172.203(p) states that the word “non-odorized” or “not-odorized” must be included in association with the proper shipping description on a shipping paper when non-odorized LPG is offered for transportation. If the non-odorized gas or gas mixture meets the definition of LPG, then the shipping description must include “non-odorized” or “not-odorized” regardless of whether the assigned proper shipping name is specifically “Petroleum gases, liquefied or Liquefied petroleum gas.” Q2. Does the marking requirement for “NON-ODORIZED” or “NOT ODORIZED” apply to these specific gases when offered in cylinders, portable tanks, or cargo tanks? A2. Yes. The marking requirements in § 172.301(f) for cylinders, § 172.326(d) for portable tanks, and § 172.328(e) for cargo tanks apply to any non-odorized gas or gas mixture that meets the definition of LPG. Just as with the shipping paper requirements, if the LPG is 1 49 FR 64462, 64463 (Nov. 4, 2004).#

Page 2offered for transportation without odorization, the package must be marked “NON- ODORIZED” or “NOT ODORIZED” as specified in the applicable section. I hope this information is helpful. Please contact us if we can be of further assistance. Sincerely, Dirk Der Kinderen Chief, Standards Development Branch Standards and Rulemaking Division#

Page 3Cardez, E. 26-0026 From: INFOCNTR (PHMSA) To: Baker, Yul (PHMSA) Cc: Hazmat Interps Subject: FW: Request for letter of interpretation Date: Wednesday, February 18, 2026 16:09:43 Good afternoon, Please see the below interpretation request. The mailing address is: ODOT C.C.D. attn: Andrew Zikmund 5920 Highway 30 Huntington, OR 97907 Let us know if you need anything, Janaye From: ZIKMUND Andrew G <Andrew.G.ZIKMUND@odot.oregon.gov> Sent: Tuesday, February 17, 2026 6:15 PM To: PHMSA HM InfoCenter <PHMSAHMInfoCenter@dot.gov> Subject: Request for letter of interpretation You don't often get email from andrew.g.zikmund@odot.oregon.gov. Learn why this is important Info Center: This is a request for a written interpretation of the applicability of certain regulations as they apply to shipments of non-odorized liquefied petroleum gas. 1. 49CFR part 172.203(p) requires the word “non-odorized” or “not-odorized” to be entered in association with the proper shipping description on a shipping paper when non-odorized LPG is offered for transportation. Would part 172.203(p) apply also to non-odorized shipments of: UN1011, Butane, 2.1? non-odorized shipments of UN1978 propane, 2.1? and non-odorized shipments of UN1077 Propylene, 2.1? 2. I would ask the same question with regards to 49CFR part 172..301(f) for cylinder marking , 172.326(d) for portable tank marking and 172.328(e) for cargo tank marking.#

Page 4Thank you for your assistance with these questions. Andrew Zikmund Compliance Specialist O.D.O.T. Commerce and Compliance Division Phone: (541) 207-5294 Fax: (541) 869-2026#