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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 #17-0096

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

Interpretation Response Details

Response Publish Date:

Company Name: Tracerco

Individual Name: Andrew Booton

Location State: TX Country: US

View the Interpretation Document

Response text:

Andrew Booton
Operations Manager
4106 New West Drive
Pasadena, TX  77507

Reference No. 17-0096

Dear Mr. Booton:

This letter is in response to your August 24, 2017, email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to limited quantities of compressed gas. You describe a scenario in which your facility will be shipping "UN1971, Natural gas, compressed" in U.S. Department of Transportation (DOT) 3E specification cylinders to your laboratories for analysis. Each cylinder will have a volume (meaning capacity) of less than 4 fluid ounces; will have a service pressure of 1,800 psi; and will be placed in hard‑plastic cases with foam inners to meet the strong outer packaging requirements.

We have paraphrased and answered your questions as follows:

Q1. You ask if a shipment of approximately 20 cylinders in hard-plastic cases, with each case having a gross weight of less than 30 kg (66 pounds), would be excepted from the labeling and shipping paper requirements as prescribed in § 173.306.

A1. Based on the scenario you provided, the subsequent phone conversation with a member of my staff regarding the clarification and meaning of the word "volume" versus "capacity," and the provisions found in § 173.306(a)(1), your shipment would be excepted from the labeling (unless the material is offered for transportation or transported by aircraft) and specification packaging requirements. The material must be packaged in containers meeting the capacity requirements of § 173.306(a)(1) of not more than 4 fluid ounces and the completed package may not exceed 30 kg (66 pounds) gross weight. Additional exceptions for limited quantities of compressed gas meeting (a)(1) are found in § 173.306(i) including exception from shipping paper requirement, if the package and transport meets the conditions in paragraph (i). Note, you are not required to use specification packaging (e.g., DOT 3E); however, if you choose to use this type of packaging as the container and represent it as a DOT 3E as qualified for transportation, you must adhere to the specification and continued service requirements for a DOT 3E cylinder. Otherwise, you must obliterate or cover the markings that indicate it is a DOT 3E cylinder qualified for transportation.

Q2. You ask if § 173.306(a)(2) would be applicable to your packaging of "UN1971."

A2. The requirements of § 173.306(a)(2) are for refillable metal containers that are filled with a material that is not classed as a hazardous material and then charged with a non-flammable (non-poisonous), non-liquefied gas.  Based on the information you have provided, the material you have is a Division 2.1 flammable gas and, therefore, would not be eligible for § 173.306(a)(2).

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

Regulation Sections

Section Subject
173.306 Limited quantities of compressed gases