Alternate Leakproofness Test
Pipeline and Hazardous Materials Safety Administration · Oct 18, 2001 · Reference No. 01-0177
Interprets: 49 CFR § 173.28
Reggie’s quick take
A company that tests used drums asked whether its own air pressure test meets the reuse rules in § 173.28 for UN 1H1 drums. PHMSA says the method conforms to Appendix B to Part 178 and to the reuse provisions in § 173.28(b). The 3 psi test is only suitable for drums marked for PG II or PG III liquids. Drums for PG I materials need a leakproofness test at 7 psi.
Written by AI (Claude) on Oct 22, 2026. Robots make mistakes and leave things out, so the letter below is what counts. Not legal advice.
This responds to your July 13, 2001 letter requesting clarification on cleaning and testing a UN 1H1 drum for reuse under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180). Specifically, you ask whether your new air pressure test satisfies requirements for reuse of packagings in § 173.28.
You have developed your own pressure testing machine that will apply 3 psi of air and hold it for the specified time frame. You want to air pressure test your drums in order to make them acceptable for reuse for transporting hazardous materials on common carriers.
Based on the information provided in your letter, it is the opinion of this Office that your new method of pressure testing conforms to Appendix B to Part 178 - Alternate Leakproofness Test Methods and with the reuse provisions in § 173.28(b). However, leakproofness testing at 3 psi will only be suitable for drums marked for PG II or PG III liquids; PG I materials require a leakproofness test conducted at 7 psi.
A letter of interpretation applies the regulations to the facts the requester described. It isn’t a regulation and isn’t legal advice. The agency’s copy.