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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 #20-0053

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

Interpretation Response Details

Response Publish Date:

Company Name: Hasa, Inc.

Individual Name: Dave Johnson

Location State: CA Country: US

View the Interpretation Document

Response text:

April 27, 2021

Mr. Dave Johnson
Hasa, Inc.
23119 Drayton Street
Saugus, CA 91350

Reference No. 20-0053

This letter is in response to your July 17, 2020, letter and subsequent emails requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to pressure differential testing. In your letter, you state that your company reuses and refills 5, 15, 30, and 55 gallon polyethylene drums—rated for Packing Group (PG) II or III materials—with materials similar to materials the drums previously contained. You ask whether your company's proposed test procedure, as outlined below, is in compliance with the pressure differential testing requirements specified in paragraph 2 of Appendix B to Part 178 - Alternative Leakproofness Test Methods.

You described your proposed test procedure as follows:

  • A test fixture with a single pressure gauge is connected to an opening in the drum. All other openings on the drum are sealed with closures.
  • Utilizing a compressed air source and hand valve, the drum under test is pressurized to 3 psig, as indicated on a single pressure gauge measuring the internal pressure of the drum.
  • A hand valve is closed, isolating the air source from the drum and pressure gauge measuring the internal pressure of the drum.
  • The pressure gauge is monitored for one minute. If no pressure drop is observed on the pressure gauge, the drum is considered to pass the test and is marked accordingly, per § 173.28. If the pressure is not maintained, the drum is considered to fail and is marked out of service and disposed of through a plastic recycler.

It is the opinion of this Office that the proposed test procedure you describe complies with the pressure differential test requirements in paragraph (2) of Appendix B to Part 178. Therefore, the PG II and III polyethylene drums that successfully pass this test may be reused and refilled under § 173.28, provided these packagings comply with all applicable requirements of the HMR. Please be advised that plastic drums may expand under pressure. Therefore, it is recommended that the drums be pressurized to 20kPa and held at that pressure prior to testing. In addition, as it may be difficult to detect a slow leak, it is also recommended that a low-pressure gauge be used.

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

Regulation Sections

Section Subject
173.28 Reuse, reconditioning and remanufacture of packagings