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Interpretation Response #98-0184 ([American Association for Respitory Care] [Ms. Kathleen Adams])

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

Interpretation Response Details

Response Publish Date:

Company Name: American Association for Respitory Care

Individual Name: Ms. Kathleen Adams

Location State: TX Country: US

View the Interpretation Document

Response text:

OCT 7, 1998


Ms. Kathleen Adams                  Ref. No. 98-0184
Chair, Transport Section
American Association
for Respitory Care
11030 Ables Lane
Dallas, TX 75229-4593

Dear Ms. Adams:

This is in response to your letter of July 7, 1998, requesting clarification on the use of nitric oxide and nitrogen mixtures for medical use under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180). Specifically you ask if a mixture comprised of .08% nitric oxide with the balance nitrogen is regulated when used in ground ambulances, medical helicopters and medical fixed wing aircraft.

It is the opinion of this Office that a compressed gas mixture containing .08% of nitric oxide with the balance nitrogen is properly classed as Division 2.2. Such a gas is not poisonous by inhalation.

An ambulance that uses a compressed gas to treat a patient being transported is not regulated under the HMR. Such materials are not being transported as items of commerce and are not subject to the HMR. It is regulated, however, when transported on board commercial medical helicopters and medical fixed wing aircraft.

For your information, as provided by § 175.10(a) (14), a transport incubator unit necessary to protect life transported by aircraft is not regulated under the HMR when: (1) the compressed gas used to operate the unit is in an authorized DOT specification cylinder which is marked, labeled, filled and maintained as prescribed by the HMR; (2) any batteries used in its 9peration are of the non-spillable type; (3) the unit is constructed so that valves, fittings, and gauges are protected from damage; (4) the pilot in command is advised that the unit is onboard and when it is intended for use; {5} it is accompanied by a person qualified to operate it; (6) it is secured in the aircraft in a manner that does not restrict access to or use of any required emergency or regular exit or of the aisle in the passenger compartment; and (7) there is no smoking within ten feet of the unit.

An incubator unit using a Division 2.2 (non-flammable gas) compressed gas mixture is not regulated for air transport when the above conditions are met. Therefore, you may transport an incubator as described above as unregulated.

I hope this information is helpful.



Delmer F. Billings
Chief, Standards Development
Office of Hazardous Materials Standards


Regulation Sections

Section Subject
172.101 Purpose and use of hazardous materials table