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Interpretation Response #09-0223 ([Hydrotest Tech.] [Mr. David A. Wright])

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

Interpretation Response Details

Response Publish Date:

Company Name: Hydrotest Tech.

Individual Name: Mr. David A. Wright

Location State: TX Country: US

View the Interpretation Document

Response text:

January 5, 2010





Mr. David A. Wright

Fire Extinguisher/ DOT Cylinder

Hydrotest Tech.

Building 1745 1st Avenue

NAS Corpus Christi, TX 78419

Ref. No.: 09-0223

Dear Mr. Wright:

This responds to your facsimile letter regarding the correct identification number under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) for a shipment of fully charged "Amerex Model 600, Halon 1211 Flightline Wheel Units" from NAS in Corpus Christi, Texas to JRB in Fort Worth, Texas.

According to your letter, "Flightline Wheel Units" are DOT 4BW240 specification cylinders, maintained by your organization, and placarded with the identification number "UN1956" (containing Halon 1211 + N2). The MSDS uses the identification number "UN1974." You ask for guidance in determining the correct identification number to use to ship these cylinders.

You did not provide sufficient information (e.g., hazard characteristics, MSDS, etc.,) on your product to enable us to make a determination regarding classification. Under 49 CFR 173.22, it is the shipper's responsibility to properly classify a hazardous material. This office does not perform that function. Under the HMR, the UN numbers "UN1956" and "UN1974" are the identification numbers for the descriptions "Compressed gas, n.o.s., 2.2", and "Chlorodifluorobromomethane, 2.2" or "Refrigerant gas, R 12B1", respectively.

The HMR specify requirements for classification, packaging, preparation of shipping papers, marking, labeling, placarding, emergency response information, and training. The definition and packaging requirements for compressed gases are found in 49 CFR 173.115 and 173.302, respectively. A list of commercial suppliers of the HMR is enclosed. You may also access the HMR at

I hope this information is helpful. If we can be of further assistance, please contact us.


Charles E. Betts

Chief, Standards Development

Office of Hazardous Materials Standards


173.22, 173.115, 173.302

Regulation Sections

Section Subject
173.115 Class 2, Divisions 2.1, 2.2, and 2.3-Definitions
173.22 Shipper's responsibility
173.302 Filling of cylinders with nonliquefied (permanent) compressed gases or adsorbed gases