Interpretation Response #15-0157 ([Fleet Services Business Department] [Ms. Elizabeth Carson])

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

Interpretation Response Details

Response Publish Date: 10/29/2015

Company Name: Fleet Services Business Department

Individual Name: Ms. Elizabeth Carson

Location State: NM Country: US

View the Interpretation Document

Response text:

October 29, 2015

Ms. Elizabeth Carson
Department of Transportation Program Lead
Fleet Services Business Department
P.O. Box 5800
MS0950
Albuquerque, New Mexico  87185-0950

Reference No. 15-0157

Dear Ms. Carson:

This is in response to your July 14, 2015 letter requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the shipment of an emptied non-specification pressure cylinder used to store hydrogen gas at your facility.  In your letter, you state that you have a hydrogen storage system that incorporates mounted non-Department of Transportation (DOT) specification cylinders.  The system is filled with 12,690 pounds per square inch (psi) of Hydrogen while at a fixed location.  Your intent is to vent and purge the cylinders with nitrogen gas before transporting the cylinders by highway.  You add that this process will leave a 97% Nitrogen / 3% Hydrogen gas composition at less than 29 psi inside the cylinders.  You ask if the non-DOT specification cylinders that are cleaned and purged as you describe would constitute an empty package under                                 § 173.29(b)(2)(iv)(B).  

Provided that the empty packaging described in your letter is cleaned and purged in accordance with § 173.29(b)(2)(iv)(B), the answer is yes.  In addition, § 173.29(b)(2)(iii) states that an empty packaging that is refilled with a material which is non-hazardous to such an extent that any residue remaining in the packaging no longer poses a hazard is not subject to the requirements of the HMR.  Please note that for purposes of the HMR, cleaned and purged means no residual hazardous material or vapor remain in a container.  The procedure presented in your letter appears to leave the cylinders sufficiently cleaned of residue and purged of vapors to remove any potential hazard.  Your cylinders would not be considered to contain hazardous material provided any residue remaining in the cylinders no longer meets any of the hazard class definitions in the HMR.

I hope this satisfies your request.

Sincerely,

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

173.29(b)(2)(iv)(B), 173.29(b)(2)(iii)

Regulation Sections