# AMETEK AMERON — Hazardous Materials Safety Interpretation **Citation:** 24-0010R **Type / status:** guidance / guidance **Agency:** Pipeline and Hazardous Materials Safety Administration **Effective:** Not stated **Published:** 2025-01-03 24-0010R response to AMETEK AMERON concerning 171.8, 173.25, 173.301. ## Document text <<>> U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration 1200 New Jersey Avenue, SE Washington, DC 20590 January 3, 2025 Mr. Patrick Schoenhoff General Manager AMETEK AMERON 10271 Bach Boulevard Saint Louis, MO 63132 Reference No. 24-0010R Dear Mr. Schoenhoff: This letter is in response to your February 20, 2024, letter requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the overpack marking requirements in § 173.25 as they relate to cylinders. PHMSA is revising this letter to clarify that certain DOT specification cylinders require a strong outer package under § 173.301(a)(9) and therefore are not an overpack as defined in § 171.8. This response replaces Letter of Interpretation Ref. No. 24-0010. We have paraphrased and answered your questions as follows: Q1. You present a scenario where oxygen is shipped in Department of Transportation (DOT) 3AA or 3HT specification cylinders, placed in a fiberboard box, and marked “UN1072, Oxygen, Compressed.” You ask whether the fiberboard box must be marked “OVERPACK” as described in § 173.25(a)(4). A1. When offered for transportation in 3AA specification cylinders which are further packaged in a fiberboard box—the configuration meets the definition of an overpack, as defined in § 171.8—and, if the specification markings on the cylinders are not visible through the overpack, the fiberboard box must be marked “OVERPACK” as prescribed in § 173.25(a)(4). When offered for transportation in 3HT specification cylinders, the fiberboard box may not be marked “OVERPACK.” Specification 3HT cylinders are required under § 173.301(a)(9) to be packaged in a “strong outer packaging,” which is not an overpack. Q2. In connection to question Q1, you ask whether it is a violation of the HMR to mark a fiberboard box with “OVERPACK” if it does not meet the definition of an overpack as defined in § 171.8. A2. The answer is yes. Marking a fiberboard box with “OVERPACK” is a violation of the HMR if it does not meet the definition of an overpack as defined in § 171.8. <<>> Q3. You present a scenario where fire extinguishers are shipped under DOT Special Permits (SPs)—DOT SP-7945, 1 DOT SP-8495, 2 and DOT SP-127263 —and marked “UN1044, Fire Extinguishers.” You ask whether the “OVERPACK” mark is required on the fiberboard box containing fire extinguisher cylinders shipped under DOT SP-7945, DOT SP-8495, and DOT SP-12726. A3. Except when transported in DOT specification cylinders not specifically listed in § 173.301(a)(9), the answer is no. The SPs referenced in your letter authorize certain non- specification cylinders which—under the terms of the special permits—must be transported in “strong outer packaging.” In this configuration, the outer fiberboard box is not an overpack. Q4. In connection to question Q3, you ask whether it is a violation of the HMR to mark a fiberboard box with “OVERPACK” if it does not meet the definition of an overpack as defined in § 171.8. A4. See answer A2. When the SP requires the use of a strong outer packaging—as in DOT- SP 7945 paragraph 8.g. or DOT-SP 8495 paragraph 8.g.—the outer packaging does not meet the definition of an overpack, and therefore, “OVERPACK” is not an appropriate marking. In addition, paragraph 7.a. of DOT-SP 12726 states in part: "complied with the provisions of the applicable special permits." Cylinders under DOT-SP 7945 and DOT- SP 8495 authorized under DOT-SP 12726 must comply with DOT-SP 7945 and DOT-SP 8495, as applicable. When shipped under DOT-SP 12726, cylinders authorized under DOT-SP 7945 or DOT-SP 8495 must be packed in strong outer packaging and may not be marked "OVERPACK". Also note, DOT-SP 12726 paragraph 7.a. authorizes the use of both non-DOT specification cylinders and DOT specification cylinders, and—when DOT specification cylinders not specifically listed in § 173.301(a)(9) are used—the “OVERPACK” marking is required unless the markings representative of each package type contained in the overpack are visible from outside of the overpack. Finally, it should be noted that additional requirements such as cylinder valve protection, may also be required under the terms of the SP or the HMR even when “OVERPACK” is not required or authorized. I hope this information is helpful. Please contact us if we can be of further assistance. Sincerely, Steven Andrews Acting Chief, Regulatory Review and Reinvention Branch Standards and Rulemaking Division 1 https://www.phmsa.dot.gov/hazmat/documents/offer/SP7945.pdf/2022024177/SP7945 2 https://www.phmsa.dot.gov/hazmat/documents/offer/SP8495.pdf/2021114098/SP8495 3 https://www.phmsa.dot.gov/hazmat/documents/offer/SP12726.pdf/2020064323/SP12726 <<>> Pollack From: INFOCNTR (PHMSA) To: Dodd, Alice (PHMSA) Cc: Hazmat Interps Subject: FW: Overpack Interpretation Request Date: Friday, February 23, 2024 2:13:21 PM Attachments: image001.png image002.png image003.png Overpack Clarification Request.pdf 24-0010 Hi Alice, Please see the attached interpretation request. Let us know if you need anything. Sincerely, Janaye From: Patrick Schoenhoff Sent: Tuesday, February 20, 2024 2:23 PM To: PHMSA HM InfoCenter Subject: Overpack Interpretation Request 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. Hello, Please see the attached request for Interpretation of the use of Overpack labels on packages containing charged cylinders. Feel free to contact me with any questions you have with this request. Best regards, Patrick Schoenhoff Technical Director / General Manager D: +1 314 428 2062 x1077 | 10271 Bach Boulevard Saint Louis, MO 63132 www.ameronglobal.com O: +1 314 428 2062 | E: patrick.schoenhoff@ametek.com <<>> This email, and any files transmitted with it, are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error, please notify the sender and delete this email. If you are not the intended recipient, you are notified that disclosing, copying, distributing, or taking any action in reliance on the contents of this information, is strictly prohibited. <<>> AMERON 10271 BACH BOULEVARD SAINT LOUIS. MO 63132 314-428-2062 PH February 20, 2024 Mr. Shane Kelley Director, Standards and Rulemaking Division U.S. DOT/PHMSA (PHH-10) 1200 New Jersey Avenue, SE East Building, 2nd Floor Washington, DC 20590 Mr. Kelley, I am requesting a Letter of Interpretation for the Overpack labeling of packages in the following scenarios. Scenario 1: An Oxygen Cylinder with a DOT rating of either 3AA or 3HT is packaged in a fiberboard box. The box is marked with UN1072 Oxygen, Compressed labels. Question 1: Does the above packaging constitute being labeled as an “Overpack”? Question 2: If not meeting the definition or requirement of an “Overpack”, is marking the box as an Overpack a violation of the regulations? Scenario 2: A Fire Extinguisher Cylinder with a DOT SP rating of SP-8495 or SP- 7945 is packaged in a fiberboard box. The box is marked with UN1044, Fire Extinguishers SP-12726 labels and then shipped per SP-12726 (of which we hold Party Status). Question 3: Does the above packaging constitute being labeled as an “Overpack” with an SP cylinder? Question 4: If not meeting the definition or requirement of an “Overpack”, is marking the box as an Overpack a violation of the regulations? Thank you for your help on this matter, and feel free to contact me if you have any questions regarding these scenarios. Best Regards, Patrick Schoenhoff General Manager AMETEK AMERON 10271 Bach Boulevard Saint Louis, MO 63132 314-428-2062 X1077 E-mail: patrick.schoenhoff@ametek.com ## Provenance - Official: Yes - Source: - Source ID: `phmsa` - SHA-256: `012353eadba05a446d97f0e1df94dba840efeaf15fbaaadaab972835d1d8f605` - Retrieved: 2026-08-20T00:59:31.977Z - Exported: 2026-08-22T14:55:34.984Z - Document slug: `phmsa-interpretation-24-0010r` ### Source metadata ```json { "materialSubtype": "interpretation", "interpretationArea": "hazardous_materials", "representation": "full_text_from_official_pdf", "companies": [ "AMETEK AMERON" ], "individuals": [ "Patrick Schoenhoff" ], "refIds": [ "24-0010R" ], "catalogDates": [ "2025-01-03" ], "catalogParts": [ 171, 173 ], "catalogRowCount": 3, "sourceRecordUrls": [ "https://www.phmsa.dot.gov/node/76296" ], "linkedAttachmentUrls": [], "unavailableResponseUrls": [], "duplicateRepresentationUrls": [], "citedSections": [ "171.8", "173.25", "173.301", "173.301(a)(9)" ], "catalogPageUrls": [ "https://www.phmsa.dot.gov/regulations/title49/section/1718", "https://www.phmsa.dot.gov/regulations/title49/section/17325", "https://www.phmsa.dot.gov/regulations/title49/section/173301" ], "pdfUrls": [ "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/2025-01/240010R.pdf" ], "representations": [ { "viewUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/2025-01/240010R.pdf", "detailUrl": null, "detailHtmlPath": null, "pdfUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/2025-01/240010R.pdf", "pdfArtifactPath": "data/sources/phmsa-interpretations/24-0010r-67f29129c3.pdf", "pdfArtifactSha256": "11fa88ba7dcef6e7d0c03e08833d11e03c20c57ad4fec1d673921cbbb996374b", "extractedTextPath": "data/sources/phmsa-interpretations/24-0010r-67f29129c3.v2.txt", "extractedTextSha256": "4cbd2f36f07718806aef0bf3e1562d468e09b0d984fc037ad7983faab7db8c32", "pageCount": 5, "extractionVersion": 2 } ], "caveat": "Interpretations apply regulations to the facts presented and do not create independently enforceable requirements.", "jurisdiction": "US" } ```