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Interpretation Response #17-0074

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

Interpretation Response Details

Response Publish Date:

Company Name: Western International Gas & Cylinders, Inc.

Individual Name: Ms. Kathy McKenzie

Location State: TX Country: US

View the Interpretation Document

Response text:

November 16, 2017
Ms. Kathy McKenzie
Safety & Compliance Director
Western International Gas & Cylinders, Inc.
P.O. Box 668
Bellville, TX  77418
Reference No. 17-0074
Dear Ms. McKenzie:
This letter is in response to your July 13, 2017, email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the transport of “Acetylene, solvent free” as a gas sample.  Specifically, you request confirmation of your understanding that “Acetylene, solvent free” may be transported under the Hazardous Materials Table entry “UN3167, Gas sample, non-pressurized, flammable, n.o.s. (Acetylene), Class 2.1” in accordance with the requirements of § 173.306(a)(4).  
In your email, you provided data indicating that when prepared in accordance with § 173.306(a)(4), “Acetylene, solvent free” would not meet the criteria for “forbidden” but rather only exhibit the properties of a Division 2.1 flammable gas.  Additionally, you provided data indicating that the pressure in the gas sample container is below that which is required to generate an explosion, and therefore the stability issue that would typically require acetylene to be transported in solvent is not present.
As specified in § 172.101(d)(1), if any specifically listed forbidden material is diluted, stabilized, or incorporated in a device and is classed in accordance with the definitions of hazardous materials contained in Part 173 of the HMR, it is no longer considered a forbidden material.  Based on the information you provided and the requirements of the HMR, it is the opinion of this Office that the material “Acetylene, solvent free” in your scenario may be described as “UN3167, Gas sample, non-pressurized, flammable, n.o.s. (Acetylene), Class 2.1,” subject to the conditions prescribed in § 173.306(a)(4) as it would not be unstable at pressure of 15.22 psia or less.
I hope this information is helpful.  Please contact us if we can be of further assistance.
Duane A. Pfund
International Standards Coordinator
Standards and Rulemaking Division
173.306(a)(4), 172.101(d)(1)

Regulation Sections

Section Subject
172.101 Purpose and use of hazardous materials table
173.306 Limited quantities of compressed gases