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Interpretation Response #09-0242 ([DGD Inc.] [Mr. Luis Lopez])

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

Interpretation Response Details

Response Publish Date:

Company Name: DGD Inc.

Individual Name: Mr. Luis Lopez

Location State: FL Country: US

View the Interpretation Document

Response text:

November 25, 2009




Mr. Luis Lopez


DGD Inc.

1561 NW 82 Ave

Doral FL 33126

Ref. No. 09-0242

Dear Mr. Lopez:

This is in response to your October 21, 2009 email requesting clarification on the Hazardous Materials Regulations (HMR; 49 CFR 171-180) applicable to the transportation of oxygen cylinders and chemical oxygen generators on aircraft. On January 31, 2007, PHMSA published a final rule that amended the HMR applicable to the air transportation of cylinders containing oxygen and oxidizing gas and oxygen generators (HM-224B). Your questions are paraphrased and answered as follows:

Q1. Are fire extinguishers subject to the requirements in the HM-224B final rule?

A1. No. Fire extinguishers conforming to the provisions in § 173.309 are not subject to the requirements adopted in the HM-224B final rule.

Q2. Are cylinders exerting a pressure of less than 40.6 psia subject to the requirements in the HM-224B final rule?

A2. No. Under § 173.115(b), the definition of a Division 2.2 non-flammable, non-poisonous compressed gas, including an oxidizing gas, specifies that the material must exert in the packaging an absolute pressure 200 kPa (29.0 psig/43.7 psia) or greater at 20 °C (68 °F).

Q3. Are the requirements of the final rule applicable to shipments offered for transportation to an international location?

A4. Yes, when transported by aircraft. As provided in § 171.24, a package containing "Oxygen, compressed" or certain oxidizing gases must be packaged as required by Parts 173 and 178.

Q5. Are the requirements outlined in the final rule applicable to ground transportation in the United States?

A5. No. The requirements of the HM-224B final rule apply to the transport of oxygen, compressed and certain oxidizing gases by aircraft.

Q6. Do the requirements of the HM-224B final rule apply to empty oxygen cylinders or oxygen generators?

A6. No. See A2 above. Note, however, that spent chemical oxygen generators are forbidden aboard both passenger and cargo only aircraft.

Q7. Please verify that the requirements outlined in the HM-224B only apply to materials meeting the definition of a compressed gas as defined in § 173.115.

A7. See A2.

I trust this satisfies your inquiry. If we can be of further assistance, please contact us.


Charles E. Betts

Chief, Standards Development

Office of Hazardous Materials Standards

173.115(b), 173.309

Regulation Sections

Section Subject
173.115 Class 2, Divisions 2.1, 2.2, and 2.3-Definitions
173.309 Fire extinguishers