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U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation

Interpretation Response #17-0087

Below is the interpretation response detail and a list of regulations sections applicable to this response.

Interpretation Response Details

Response Publish Date:

Company Name: Safecraft Inc.

Individual Name: Steven Baker

Location State: CA Country: US

View the Interpretation Document

Response text:

February 2, 2018

Mr. Steven Baker
Director of Engineering
Safecraft Inc.
557 Clark Avenue
Pittsburg, CA 94565

Reference No. 17-0087

Dear Mr. Baker:

This letter is in response to your August 18, 2017, letter requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to fire suppression systems.  Specifically, you ask about fire suppression systems used in racing vehicles consisting of:

  • A 104–250 cubic inch cylinder, with a service pressure of 500–1,000 pounds per square inch (psi), respectively, and 1,440–2,500 psi burst pressure, respectively.
  • 5–10 pounds of 3M Novec 1230 fire extinguishing fluid.
  • Cylinder pressured to 200 psi with dry nitrogen at 70°F. (Cylinder pressure at 130 °F is approximately 225 psi.)
  • A discharge valve fitted with a 500-psi frangible metal pressure relief disc.

We have paraphrased and answered your questions as follows:

Q1. You ask if "portable" as referenced in § 173.309 applies to handheld-type fire extinguishers only.

A1. The answer is no. Section 173.309 states, "This section applies to portable fire extinguishers for manual handling and operation, fire extinguishers for installation in aircraft, and large fire extinguishers." Portable fire extinguishers may include both hand-held fire extinguishers as well as fire extinguishers that are mobile in that they can be moved from place to place (such as on wheels). However, the specifications provided in your letter indicate that the cylinders are: 1) fitted with discharge valves and a frangible metal pressure relief disc, and 2) designed for use as fixed fire suppression systems. Therefore, the cylinders would not be applicable to § 173.309. If the cylinders are non‑specification cylinders, they must meet the requirements in § 173.309(c). If they do not meet the requirements in § 173.309(c), your company would need to apply for a special permit in accordance with § 107.105 of the HMR.

Q2. You ask if Department of Transportation specification 39 cylinders are authorized for use under § 173.309.

A2. The answer is no. Only the specification cylinders listed in § 173.309(a) can be used as fire extinguishers.

Q3. You ask if fire extinguishers constructed using a non-specification cylinder per § 173.309(c) that do not contain liquefied compressed gas and are charged to 200 psi at 70°F with dry nitrogen are eligible for shipment as a limited quantity and excepted from shipping papers.

A3. Provided they meet the requirements of § 173.309(a), (b), and (c), the non-specification cylinders you describe may be eligible for limited quantity provisions under § 173.309(d).

I hope this information is helpful. Please contact us if we can be of further assistance.

Sincerely,

T. Glenn Foster
Chief, Regulatory Review and Reinvention Branch
Standards and Rulemaking Division

Regulation Sections

Section Subject
173.309 Fire extinguishers