On April 15, 1996, the Environmental Protection Agency (EPA) proposed several modifications to provisions of the rule listing regulated substances and establishing threshold quantities under section 112(r) of the Clean Air Act as amended (List Rule Amendments). The proposed List Rule Amendments, if promulgated in a final rule, would clarify or establish that part 68 does not apply to several types of processes and sources. In addition, EPA proposed, pursuant to Clean Air Act section 301(a)(1), 42 U.S.C. 7601(a)(1), to stay the effectiveness of provisions that would be affected by the proposed List Rule Amendments, for so long as necessary to take final action on the proposed List Rule Amendments. EPA received no adverse public comment on the short-term stay. Today EPA is amending part 68 to promulgate the stay, under which owners and operators of processes and sources that EPA has proposed not be subject to part 68 would not become subject to part 68 until EPA has determined whether to proceed with the List Rule Amendments. The effect of today's action will be to give owners and operators of sources affected by the proposed List Rule Amendments the same amount of time to achieve compliance with the requirements of part 68 as owners and operators of other sources in the event that EPA does not proceed with the List Rule Amendments as proposed.