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Interpretation Response #00-0133 ([Buck Research Instruments, LLC] [Mr. John Buetow])

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

Interpretation Response Details

Response Publish Date:

Company Name: Buck Research Instruments, LLC

Individual Name: Mr. John Buetow

Location State: CO Country: US

View the Interpretation Document

Response text:

November 6, 2000

Mr. John Buetow                Ref. No. 00-0133
President and CEO
Buck Research Instruments, LLC
5375 Western Ave.
Boulder, CO 80301

Dear Mr. Buetow:

This responds to your letter and telephone conversation with Dr. George Cushmac of the Office of Hazardous Materials Technology regarding the applicability of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) to your ionization cells that contain a trace amount of nitric oxide.  You intend to offer these cells to air carriers for domestic and international air transportation and it is your opinion that they should be excepted from the HMR.

You state that the ionization cells are used in a Lyman-alpha hygrometer, a humidity measuring instrument, and are made of thick glass tubes which are 1"long and 3/4" in diameter.  Each tube contains a trace (1/47.5 of an atmosphere) amount of nitric oxide under vacuum.  Ten tubes are placed in an intermediate packaging with cushioning and then placed into a strong, corrugated outer packaging.  In your opinion, if the tubes were to break or leak while in transportation, the nitric oxide would immediately mix with air and be rendered nontoxic.

Under the HMR, nitric oxide is classed as a Division 2.3 toxic gas.  However, it is also our opinion that because of the trace amount of nitric oxide in each tube and the manner in which it is packaged, the tubes would not pose a significant hazard to health during transportation and, therefore, are not subject to the HMR.

I trust this satisfies your request.  Please contact us again if we can be of further assistance.


Edward T. Mazzullo
Director, Office of Hazardous
Materials Standards


Regulation Sections

Section Subject
172.101 Purpose and use of hazardous materials table