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Interpretation Response #09-0264 ([Kelly Aerospace] [Mr. Mark Mertes])

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

Interpretation Response Details

Response Publish Date:

Company Name: Kelly Aerospace

Individual Name: Mr. Mark Mertes

Location State: KS Country: US

View the Interpretation Document

Response text:

January 28, 2011




Mr. Mark Mertes

Kelly Aerospace

3414 West 29th Street South

Wichita, KS 67217

Reference No. 09-0264

Dear Mr. Mertes:

This is in response to your e-mail and telephone conversations with members of my staff concerning the applicability of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) to cylinders containing "UN 1072, Oxygen, compressed, 2.2 (non-flammable), 5.1 (oxidizer)" residue. Specifically, you ask whether the HMR apply to the transportation of a Division 2.2 and 5.1 gas having a pressure in a container below 200 kPa (29.0 psig/43.8 psia). We apologize for the delay in responding and any inconvenience this may have caused.

PHMSA revised the definition in § 173.115(b)(1) for a Division 2.2 gas in final rules issued on January 14, 2009 and January 4, 2010. Section 173.115(b) states a Division 2.2 gas is a non-flammable, non-poisonous compressed gas that includes compressed gas, liquefied gas, pressurized cryogenic gas, compressed gas in solution, asphyxiant gas, and oxidizing gas. Therefore, as amended, a Division 2.2 gas, including one with an oxidizer subsidiary hazard, is one that exerts a gauge pressure on a packaging of at least 200 kPa at 20 °C (68 °F). In accordance with the revised definition, after January 1, 2010, a cylinder of oxygen gas that exerts a gauge pressure less than 200 kPa at 20 °C is not subject to the HMR. See Docket Nos. PHMSA"2007"0065 (HM"224D) and PHMSA"2008"0005 (HM"215J) (74 FR 2200 and 75 FR 63).

You also note that the definition in § 173.29(b)(2)(iv)(B) for an empty container of Division 2.2 gas was not revised to reflect the new lower limit of 200 kPa at 20 °C in § 173.115(b)(1), and ask if this is an error. It is. We thank you for bringing this matter to our attention and again apologize for any inconvenience this may have caused. We made this correction in the January 4, 2010 final rule we discussed in the previous paragraph.

I hope this satisfies your request.


T. Glenn Foster

Chief, Regulatory Review and Reinvention Branch

Standards and Rulemaking Division

173.115(b)(1), 173.29(b)

Regulation Sections

Section Subject
173.115 Class 2, Divisions 2.1, 2.2, and 2.3-Definitions
173.29 Empty packagings