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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 #23-0027

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

Interpretation Response Details

Response Publish Date:

Company Name: Electronic Fluorocarbons

Individual Name: Mr. Jason Bombard, PE

Location State: PA Country: US

View the Interpretation Document

Response text:

February 1, 2024

Mr. Jason Bombard, PE
Electronic Fluorocarbons
3266 Bergey Road
Hatfield, PA  19440

Reference No. 23-0027

Dear Mr. Bombard:

This is in response to your March 14, 2023, letter concerning the filling densities of specification cylinders under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180). In your letter, you ask about the maximum allowable filling density of a specification cylinder containing a mixture comprised of 30% Fluorine, 60% Nitrogen, and 10% Argon by volume. You state that you offer this mixture using the proper shipping name "UN3306, Compressed gas, toxic, oxidizing, corrosive, n.o.s. Inhalation Hazard Zone B, 2.3, (5.1, 8)." You also note that § 173.301a(d)(3) limits the pressure in a specification cylinder to no higher than its service pressure at 55°C (131°F). You ask whether there is any additional hazard posed by the fluorine content of this mixture that would further limit the service pressure of the specification cylinder.

The answer is no. Provided your material is properly classed as "UN3306, Compressed gas, toxic, oxidizing, corrosive, n.o.s. Inhalation Hazard Zone B, 2.3, (5.1, 8)," the pressure in a specification cylinder at 55°C (131°F) must be limited to the service pressure of the cylinder in accordance with §§ 173.301a(d)(3) and 173.40(b). Please note that sufficient outage must be provided so that the cylinder will not be liquid full at 55°C (131°F).

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


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

173.301a(d)(3), 173.40(b)

Regulation Sections

Section Subject
173.301 General requirements for shipment of compressed gases and other hazardous materials in cylinders, UN pressure receptacles and spherical pressure vessels
173.40 General packaging requirements for toxic materials packaged in cylinders