# Safecraft Fire Protection Systems — Hazardous Materials Safety Interpretation **Citation:** 00-0085 **Type / status:** guidance / guidance **Agency:** Pipeline and Hazardous Materials Safety Administration **Effective:** Not stated **Published:** 2000-04-04 00-0085 response to Safecraft Fire Protection Systems concerning 173.309. ## Document text <<>> U.S. Department 400 Seventh Street, S.W. of Transportation Washington, D.C. 20590 Research and Special Programs Administration MAY - 4 20CO Mr. Donald E. Warren Ref. No. 00-0085 Vice President Engineering Safecraft Fire Protection Systems 2708 Teagarden St. San Leandro, CA 94577 Dear Mr. Warren: This is in response to your letter dated March 22, 2000, regarding the applicability of the requirements contained in 49 CFR 173.309(a) of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) to your non-DOT specification fire extinguishers. Specifically, you request clarification on the requirements for the manufacture and transportation of small fire extinguishers containing liquefied compressed gases. Your questions are paraphrased and answered as follows: Q1 Is it true that a non-DOT specification cylinder that is used as a fire extinguisher and contains an extinguishing agent; such as Halon 1211 and Halon 1301, may have a volumetric capacity of no larger than 900 ml? Al. The answer is yes. See § 173.309 (a)(3)(i). Q2. If a manufacturer states that a cylinder is "approved" by Underwriters Laboratories (UL/UL.C), can it be assumed that it is a non-DOT specification cylinder and is subject to the 900 ml maximum capacity? A2. The answer is yes, if the cylinder is not marked as conforming to an applicable specification prescribed in part 178 of the HMR. A non-DOT specification cylinder usec as a fire extinguisher must fully conform to the requirement prescribed in $173.309(a) and to the general packaging requirements prescribed in § 173.24. The extinguishing agent must conform to the criteria in Special Provision 18 of § 172.102. Q3. Is it correct that a cylinder that is not marked or stamped with the applicable markings (i.e., DOT XX-XXX or DOT E-XXXX) would be classified as a non-DOT specification cylinder? Would this also include foreign-made cylinders, either unmarked/unidentified or with manufacturers information? A3. The answer is yes. See A2 above. Q4. If a fire extinguisher has an adhesive label that states, for example, "MEETS DOT REQUIREMENTS FOR ALUMINUM CYLINDERS", does this in anyway override the 900 ml capacity limit? - 000085 <<>> A4. The an not rie use The require is parion a nadation to cylinder this vorainer "MEETS DOT REQUIREMENTS". See § 173.309(a)(3)(iii). Qs. Does § 173.309 (a) provide for the use of a non-DOT specification cylinder with a capacity greater than 900 ml as a fire extinguisher if it will contain a liquefied compressed A5. The answer is no. However, you may submit an application for exemption in accordance with the procedures contained in §107.105. Your application must contain sufficient information to demonstrate that, if an exemption is issued, an equivalent level of safety will be achieved that is at least equal to that required by the regulations. Q6. Under § 173.309 (b), several DOT specification cylinders commonly used for fire extinguishers are absent from the list. For example, 4DS, 4D, welded steel cylinders which are used and shipped for aircraft fire protection, and DOT 39 cylinders which are commonly used for portable extinguishers. İs it correct that these cylinders are not limited to the 241 psig at 70 °F and 900 ml limitations as discussed above? A6. The answer is yes. The quantity limitation prescribed in § 173.306(a) is applicable only to non-DOT specification cylinders. However, those cylinders referenced in your example are not authorized for shipment under § 173.309. When filled with a liquefied compressed gas, the cylinders must be shipped in accordance with § 173.304. Q7. Are there any other requirements that specifically relate to the manufacture of non- DOT specification cylinders? A7. DOT has no requirements on the manufacture of non-DOT specification cylinders used as fire extinguishers, other than as noted in §§ 173.24 and 173.309 (a). I suggest that you contact the National Fire Protection Association for any industry standards that may be applicable to fire extinguishers. I hope this information is helpful. Sincerely, Thathe s mothell Hattie L. Mitchell, Chief Regulatory Review and Reinvention Office of Hazardous Materials Standards 2 <<>> 03/23/2000 17:00 5102976932 SAFECRAFT. Betts SAFECRAFT $173.309 BAL PROTECTION SYSTEMS 22 March 200( 20~0085 sheet 1 / 2 f. firex RSPA FAX MSG 202/365-3012 Edward T.Maazzullo, Director Research and Special Programs Administration Office of Hazardous Materials Standards, DHM-10 U.S.Department of Transportation washington, DC 20590-0001 400 7th St. Sw Re: 49 CFR $ 173.309 Fire extinguishers. Dear Sir: We are requesting clarification as to specific application of the subject DOT CFR in regards to shipping (and manufacturing) ot small tire extinguishers. We will limit our discussion to those designs that only use liquifiad compressed gas extinguishing agents. These agents are of the familiar type as follows : Halon 1301, bromotrifluoromethane, CBrEg Halon 1211, bromochlorodifluoromethane, CHICIF2 EM 200™M, 1,1,1,2,3, 3, 3-heptafluoropropane, CF3CHECF3 FE-13, FE-25, FE-36, FE-241, (DuPont Agents) are of the (liguified) compressed gas definition. i.e. not water based or dry chemical. There seems to be a lot of confusion in the industry about shipping of these fire extinguishing agents within a variety of nonspecification cylinders. Our questions relate to $ 173.309 Fire extinguishers, unless otherwise noted. .. Is it true that an extinguisher that uses a nonspecification jes cylinder pressurized with any of the compressed gas agents above can be NO LARGER THAN 900ml.? 2. If a manufacturer claims that their cylinder is "approved" by Underwriters Laboratories (UL/ULC), does this still mean that 1t is a NONSPECIFICATION cylinder and is subtect to the 900ml maximum capacity ? yes 3. Is it correct that any cylinder that is NOT marked or stamped with designation DOT XX-XXX or DOT E-XXXX would be classified as See: 173247 a NONSPECIFICATION cylinder 2 Would this include foreign (made) cylinders, either unmarked/unidentified or with manufacturers information ? 2708 Teagarden St. San Leandro CA 94577 Ph: 800-400-2259 Fx: 510-297-6932 <<>> 03/23/2000 17:00 5102976932 SAFECRAFT PAGE 02 22 March 2000 sheet 2 / 2 I. firex RSPA No. example, 4. If a fire extinguisher has an adhesive label tratestates s07 anyway override the 900m1 capacity limit? REQUIREMENTS FOR ALUMINUM CYLINDERS", 5. Within pressure 11mit of 24ipsig @ 70°F, there are several references to the first paragraph of S173.309 (a) after charge No. conditions and exceptions. anything that we may have missed that allows transportation of a in parts 172, 174 and 177. Is there fire extinguisher using liquified agents in nonspecification cylinders greater than 900ml ? Limitat. 6, Inder S173.309 (b) there are several DOT specification cylinders commonly used for fire extinguishers absent from this of apple list. Examples are 4DS, 4D, ADA welded steel cylinders used and to nonse Shipped for aircraft fire protection, and DOT 39 commonly used cylinders are limited to the 24lpsig and 900ml rules as discussed tor portable extinguishers. Is it correct that none of these specifically relate to the manufacture of NONSPECIFICATION 7. Are there any 49 CFR parts or other DOT requirements that cylinders ? clarification. If you need discussion with me, please call on We hope that we are reasonably clear in our request foI 510/297-6931. Sincerely ## Provenance - Official: Yes - Source: - Source ID: `phmsa` - SHA-256: `4da914afccd1e93aa01384bbe55fd57cfa65c6b979a123850067cd78811b9580` - Retrieved: 2026-08-20T00:59:31.977Z - Exported: 2026-08-23T19:05:31.632Z - Document slug: `phmsa-interpretation-00-0085` ### Source metadata ```json { "materialSubtype": "interpretation", "interpretationArea": "hazardous_materials", "representation": "full_text_from_official_pdf", "companies": [ "Safecraft Fire Protection Systems" ], "individuals": [ "Mr. Donald E. 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