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Interpretation Response #12-0087 ([Hydro-Test Products, Inc.] [Mr. Tom Sauta])

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

Interpretation Response Details

Response Publish Date:

Company Name: Hydro-Test Products, Inc.

Individual Name: Mr. Tom Sauta

Location State: MA Country: US

View the Interpretation Document

Response text:

June 25, 2012



Mr. Tom Sauta
Hydro-Test Products, Inc.
85 Hudson Road
Stow, MA 01775

Ref. No. 12-0087

Dear Mr. Sauta:

This responds to your April 4, 2012 request for clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180). In your letter, you state that cylinder retesters are confused in regard to the definition of a fire extinguisher under § 180.209(j). This section references Special Provision 18 in § 172.102(c)(1). Special Provision 18 provides certain conditions that a cylinder and extinguishing agent must meet for the combination to be used as a fire extinguisher, but the special provision does not provide a charged pressure limit for the cylinder. Specifically, you provide two scenarios involving slightly different DOT 4B specification cylinders and ask if they would meet the criteria to be requalified as a fire extinguisher under § 180.209(j).

The scenarios that you provide are restated below:

Scenario 1. A cylinder marked with DOT4B500 filled with a dry chemical extinguishing powder agent, Mon-Ammonium phosphate and pressurized with 350 psi of dry Nitrogen with a dew point of minus 52°F or lower. The cylinder has a water capacity of 18 pounds. The cylinder is used as part of a pre-engineered fixed fire extinguishing system. This is not being used as a hand operated portable fire extinguisher.

Scenario 2. Same as Scenario 1, but with a water capacity of 10 pounds.

Based on the information in your letter and provided that the cylinders that you describe comply with DOT 4B specification requirements, Special Provision 18, and other applicable requirements under the HMR (e.g., as specified in § 173.301(f) the cylinders must be fitted with a pressure relief device system), they meet the criteria in § 180.209(j) to be requalified as fire extinguishers. The cylinder with water capacity of 10 pounds must be requalified in accordance with § 180.209(j)(1)(i), and, the cylinder with water capacity of 18 pounds must be requalified in accordance with § 180.209(j)(1)(ii).

I hope this answers your inquiry. If you need additional assistance, please call this office at (202) 366-8853.



Robert Benedict
Chief, Regulations Development Branch
Standards and Rulemaking Division

180.209(j), 173.301, 172.102 SP 18

Regulation Sections

Section Subject
173.301 General requirements for shipment of compressed gases and other hazardous materials in cylinders, UN pressure receptacles and spherical pressure vessels
180.209 Requirements for requalification of specification cylinders