Approval effectiveness: Portable Tanks
Pipeline and Hazardous Materials Safety Administration · Sep 8, 1992 · Reference No. 92-0076
Reggie’s quick take
Someone asked whether an interim approval for a portable tank still works. The approval covers shipments of nitromethane mixtures with at least 40% 1,2-butylene oxide by weight, in an 1M 101 portable tank. The agency says it stays valid until October 1, 1996, under the HM-181 transition period. Until then, the approval can still be used for those mixtures, as long as the shipment meets the approval's terms.
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 is in reply to your letter of May 26, 1992, regarding the effectiveness of an 1M Portable Tank interim approval issued by DOT on February 8, 1983. That approval authorized transportation of nitromethane mixtures containing no less than 40% by weight of 1,2-butylene oxide in an 1M 101 portable tank under the conditions specified in the interim approval.
This interim approval is valid until October 1, 1996, pursuant to the transition period provision given in HM-181. Therefore, you may continue to use the interim approval to transport nitromethane mixtures meeting the terms prescribed in the approval.
I hope this information is helpful. If we can be of further assistance, please contact us.
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.