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U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation

Interpretation Response #12-0260 ([TEN-E Packaging Services, Inc.] [Mr. Robert J. Ten Eyck])

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

Interpretation Response Details

Response Publish Date:

Company Name: TEN-E Packaging Services, Inc.

Individual Name: Mr. Robert J. Ten Eyck

Location State: MN Country: US

View the Interpretation Document

Response text:

February 14, 2013



Mr. Robert J. Ten Eyck
Director, Technical Services
TEN-E Packaging Services, Inc.
1666 County Road 74
Newport, MN  55055

Reference No. 12-0260

Dear Mr. Ten Eyck:

This is in response to your November 12, 2012 letter requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the definition of an "aerosol."  In your letter, you describe a microfoam delivery system that consists of two separate 300 ml (10.25 ounces) canisters, one that contains "UN 1072, Oxygen, compressed, 2.2 (non-flammable compressed gas), 5.1 (oxidizer)" under 5.4 bars of pressure and the other that contains a foaming product that does not meet the definition of a Department of Transportation hazard class and "UN 1013, Carbon dioxide, 2.2" under 1.2 bars of pressure.  You also state these canisters are joined together with a protective collar equipped with a safety clip and a packaging system that allows the two canisters to be twisted together, the oxygen dispensed into the canister with the foaming product, and the pressurized foaming product to be released at the time of use through the use of manometer tubing and syringe.  You ask whether the microfoam delivery system meets the definition of an "aerosol." 

The answer is no.  The HMR defines an aerosol as "any non-refillable receptacle containing a gas compressed, liquefied or dissolved under pressure, the sole purpose of which is to expel a nonpoisonous (other than a Division 6.1 Packing Group III material) liquid, paste, or powder and fitted with a self-closing release device allowing the contents to be ejected by the gas" (see § 171.8).  Based on the information you provided, the canister that contains the foaming product and carbon dioxide meets the definition of an aerosol after it has been charged with oxygen from the other canister, and this occurs when both canisters are no longer in transportation.  While in transport, the canister that contains the foaming product is not under sufficient pressure at 1.2 bars of pressure to allow its product to be expelled.  Further, the canister containing 300 ml of oxygen exceeds the 4 ounce capacity limit under § 173.306(a)(1) that would allow it to be transported as a limited quantity.  Therefore, it is the opinion of this Office that the canister containing the foaming product is not regulated as a hazardous material under the HMR, and the canister that contains the oxygen must be described as "UN 2037, Receptacles, small, containing gas (gas cartridges), 2.2, 5.1" or "UN 1072, Oxygen, compressed, 2.2."

I hope this satisfies your request.


T. Glenn Foster
Chief, Regulatory Review and Reinvention Branch
Standards and Rulemaking Division

171.8, 173.306

Regulation Sections

Section Subject
171.8 Definitions and abbreviations
173.306 Limited quantities of compressed gases