# Kidde Residential and Commercial Division — Hazardous Materials Safety Interpretation **Citation:** 17-0052 **Type / status:** guidance / guidance **Agency:** Pipeline and Hazardous Materials Safety Administration **Effective:** Not stated **Published:** 2017-08-30 17-0052 response to Kidde Residential and Commercial Division concerning 173.309. ## Document text <<>> Mr. Ronald C. Mauney Senior Product Design Engineer Kidde Residential and Commercial Division 1016 Corporate Park Drive Mebane, NC 27303 Reference No. 17-0052 Dear Mr. Mauney: This letter is in response to your April 28, 2017, letter requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to fire extinguishers. Specitically, you reterence § 173.309(c)(4) of the HMR, which requires a fire extinguisher be tested, without evidence of failure or damage, to at least three times its charged pressure at 21 °C (70 °F) but not less than 825 kPa before initial shipment, and be marked to indicate the year of the test within 90 days of the actual date of the original test. You ask if this regulation intends for the testing stamp year to reflect the year the fire extinguisher was tested, as opposed to the year the cylinder was manufactured. The intention of the testing requirement in § 173.309(c)(4) is to mark the cylinder with the year the fire extinguisher was tested and place the marking on the fire extinguisher within 90 days of the actual date of the original test. For example, if a cylinder was manufactured in 2015, subjected to testing in 2017, and thus put into use as a fire extinguisher; the stamp should be marked as 2017 within 90 days of such testing. I hope this information is helpful. Please contact us if we can be of further assistance. Sincerely, kenn Foster T. Glenn Foster Chief, Regulatory Review and Reinvention Branch Standards and Rulemaking Division <<>> Washington, DC 20590-0001. 28-April-2017 To Whom It May Concern: We are writing to obtain an interpretation of a provision contained within the Code of Federal Regulations, which states as follows: (c) Non-Specification cylinders are authorized as fire extinguishers subject to the following conditions: ***** (4) Each fire extinguisher must be tested, without evidence of failure or damage, to at least three times its charged pressure at 21 °C (70 °F) but not less than 825 kPa (120 psig) before initial shipment, and must be marked to indicate the year of the test (within 90 days of the actual date of the original test) and with the words "MEETS DOT REQUIREMENTS' This marking is considered a certification that the fire extinguisher is manufactured in accordance with the requirements of this section. The words "This extinguisher meets all requirements of 49 CFR 173.306" may be displayed on fire extinguishers manufactured prior to January 1, 1976; 49 CFR § 173.309 (c)(4). The purpose of this regulation is to insure the strength and integrity of the fire extinguisher cylinder prior to shipping through commerce. This is done through hydrostatic testing. The issue that requires clarification is what date stamp should appear on the product? The regulation itself is not clear, and refers to testing and dating the "fire extinguisher" within 90 days of the actual date of the original hydrostatic test. Hydrostatic testing involves filling the cylinder with a liquid, usually water, and ressurization of the vessel to the specified test pressine. A finished fire extingsarging <<>> extinguisher with the new date stamp. By way or example, a cuto cylinder could be subjected to a hydrostatic test in 2017, turned into a fire extinguisher, and the date stamp modified to reflect the accurate date of the test and assembly of the final product. We would like clarity on this regulation, and appreciate your time and consideration. Regards, londd c. Mury Ronald C. Mauney Senior Product Design Engineer Kidde Residential and Commercial Division 1016 Corporate Park Drive Mebane, NC 27303 Tel: (919) 304-8203 Fax: (919) 304-8205 Ronald. Mauney@kiddeus.com ## Provenance - Official: Yes - Source: - Source ID: `phmsa` - SHA-256: `f79f82aae71fce03a353d427379831f0bdc3cb969e404e70929b1aab0e96f90e` - Retrieved: 2026-08-20T00:59:31.977Z - Exported: 2026-08-22T21:22:58.458Z - Document slug: `phmsa-interpretation-17-0052` ### Source metadata ```json { "materialSubtype": "interpretation", "interpretationArea": "hazardous_materials", "representation": "full_text_from_official_pdf", "companies": [ "Kidde Residential and Commercial Division" ], "individuals": [ "Mr. Ronald Mauney" ], "refIds": [ "17-0052" ], "catalogDates": [ "2017-08-30" ], "catalogParts": [ 173 ], "catalogRowCount": 1, "sourceRecordUrls": [ "https://www.phmsa.dot.gov/node/55776" ], "linkedAttachmentUrls": [], "unavailableResponseUrls": [], "duplicateRepresentationUrls": [], "citedSections": [ "173.309", "173.309(c)(4)", "173.306" ], "catalogPageUrls": [ "https://www.phmsa.dot.gov/regulations/title49/section/173309" ], "pdfUrls": [ "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2017/170052.pdf" ], "representations": [ { "viewUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2017/170052.pdf", "detailUrl": null, "detailHtmlPath": null, "pdfUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2017/170052.pdf", "pdfArtifactPath": "data/sources/phmsa-interpretations/17-0052-7565ffe610.pdf", "pdfArtifactSha256": "9a5a670b36d10030ea4d47b98dccf6a3a418e7fb1bca5f368115fb7cba88d065", "extractedTextPath": "data/sources/phmsa-interpretations/17-0052-7565ffe610.v2.txt", "extractedTextSha256": "a6b34e71391a4674265c0a0482ec8e2a63c43c10b3dcaf022c96697b77ae6c2f", "pageCount": 3, "extractionVersion": 2 } ], "caveat": "Interpretations apply regulations to the facts presented and do not create independently enforceable requirements.", "jurisdiction": "US" } ```