Interpretation Response #19-0049
Below is the interpretation response detail and a list of regulations sections applicable to this response.
Interpretation Response Details
Response Publish Date:
Company Name: Linde Gas North America
Individual Name: Billy Stover
Location State: NJ Country: US
View the Interpretation Document
Response text:
August 14, 2019
Mr. Billy Stover
HSE Transport Safety and Compliance Manager
Linde Gas North America
200 Somerset Blvd.
Suite 6000
Bridgewater, NJ 08807
Reference No. 19-0049
Dear Mr. Stover:
This letter is in response to your April 10, 2019, letter requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to filling limits for cylinders. Specifically, you request clarification regarding the use of Department of Transportation (DOT) 3A and 3AA cylinders for the transport of Deuterium. In your letter, you state that on January 21, 2016, a final rule was published in the Federal Register (HM-233F; 81 FR 3636) that incorporated DOT Special Permit 6530 (SP 6530) which allowed certain 3-series cylinders of hydrogen and hydrogen mixtures to be filled to 110 percent of their marked service pressure. This incorporation was added as a new paragraph, § 173.302a(c). You also state that because of this revision to the HMR, you believe that it is not necessary to be a party to this SP, mark the SP number on your trailers, or maintain a copy of the SP on board the trailers and at the fill site.
We have paraphrased and answered your questions as follows:
Q1. You ask whether the HMR currently allow Deuterium and Deuterium gas mixtures to be transported in DOT 3A and 3AA cylinders and filled to 110 percent of their marked service pressure.
A1. The answer is no. Deuterium and Deuterium gas mixtures were not included in SP 6530 until December 2, 2015. The HM-233F Notice of Proposed Rulemaking (NPRM) [80 FR 5340], Section I., Executive Summary, stated that the proposal was based on a review of all active special permits as of January 1, 2013. Deuterium and Deuterium gas mixtures were not authorized in SP 6530 as of January 1, 2013, and thus were not considered in the adoption of the SP in the rulemaking. As currently written, § 173.302a(c) does not allow cylinders containing Deuterium or Deuterium gas mixtures to be filled to 110 percent of their marked service pressure.
Q2. You ask why Deuterium and Deuterium gas mixtures are included in SP 6530 but not included in the current HMR.
A2. Please see answer A1.
Q3. Provided the HMR do not authorize Deuterium and Deuterium gas mixtures to be filled to 110 percent of their marked service pressure, you ask whether you may utilize the 10 percent overfill allowance.
A3. As currently written, § 173.302a(c) does not authorize cylinders of Deuterium and Deuterium gas mixtures to be filled to 110 percent of their marked service pressure. However, SP 6530, to which your company appears to be a party, continues to be active and allows this overfill. Therefore, provided you continue to comply with the terms and conditions of the SP, you may overfill the specified cylinders to 110 percent of their marked service pressure.
I hope this information is helpful. Please contact us if we can be of further assistance.
Sincerely,
T. Glenn Foster
Chief, Regulatory Review and Reinvention Branch
Standards and Rulemaking Division
173.302a(c)