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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 #18-0025

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

Interpretation Response Details

Response Publish Date:

Company Name: FHP-CVE West Palm Beach Office

Individual Name: Sergeant Steve L. Brown

Location State: FL Country: US

View the Interpretation Document

Response text:

July 13, 2018

Sergeant Steve L. Brown
FHP-CVE West Palm Beach Office
Lake Worth Service Plaza, Bldg 9320
Milepost 94, Florida Turnpike
Lake Worth, FL  33467

Reference No. 18-0025

Dear Sergeant Brown:

This letter is in response to your February 19, 2018, email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to exceptions for “UN1073, Oxygen, refrigerated liquid (cryogenic liquid)” under § 173.320.

We have paraphrased and answered your questions as follows:

Q1. You ask whether the labeling and placarding requirements in Subparts E and F of Part 172 apply to “UN1073, Oxygen, refrigerated liquid” with respect to § 173.320(a)(2).
A1. The answer is yes.  All subparts of Part 172, including Subparts E and F, are applicable when shipping cryogenic liquids (i.e., refrigerated liquid oxygen) in accordance with § 173.320.
Q2. You ask whether non-specification cylinders, cargo tanks, and portable tanks are authorized for refrigerated liquid oxygen when shipping in accordance with the exceptions for cryogenic liquids in § 173.320(a).
A2. The answer is yes, provided the requirements of § 173.320(a) are met.  To use the exceptions provided in § 173.320, cryogenic liquids—such as UN1073—must be transported in Dewar flasks, insulated cylinders, insulated portable tanks, insulated cargo tanks, or insulated tank cars that are designed and constructed so that the pressure will not exceed 25.3 psig under ambient conditions.  Note that shipping under this exception is restricted to transportation by rail and highway.

I hope this information is helpful.  Please contact us if we can be of further assistance.


Dirk Der Kinderen
Chief, Standards Development Branch
Standards and Rulemaking Division

173.320, 173.320(a)(2), 173.320(a)

Regulation Sections

Section Subject
173.320 Cryogenic liquids; exceptions