Limit EPA reliance on CAA Section 301 general rulemaking authority

Research notes

• Negative search (2026-08-27): no EPA rule, proposed rule or notice in the window announces a limit on the agency’s reliance on §301 general rulemaking authority, and the Federal Register full-text search for the section returns only rules that cite it in their authority blocks.
• This is a self-restraint ask with no natural instrument: the way it would show up is a preamble disclaiming §301 as a source of substantive authority, which is not something a title search can find.
• Preamble search 2026-09-06. Status unchanged. A title search could not answer this, so the Federal Register full-text API was run against preamble text, restricted to EPA and to publication dates from 2025-01-20, with a control first. Control: “zzqqxnonsenseterm” → 0, “endangerment finding” → 12. So the zeroes below are measurements.
  • “Clean Air Act section 301” → 0
  • “section 301(a)(1) of the Clean Air Act” → 0
  • “substantive authority elsewhere” → 0
  • “general rulemaking authority” → 4, and none is about CAA §301: two Ohio and Michigan ozone redesignation proposals, one Indiana CSAPR allowance rule, and the May 2026 HFC reconsideration, whose hit reads “the authority to promulgate this rule arises out of the Agency’s subsection (i) authority and is not solely derived from general rulemaking authority under subsection (k)(1)(A)” — the AIM Act, not the Clean Air Act.
  • “42 U.S.C. 7601” (the section’s US Code cite) → 6, every one an authority-block citation or a reference to §301(d)‘s treatment of Tribes as States.
• So the ask’s own words return nothing and the section’s citation returns only routine use. That is the shape the note already described, now measured rather than asserted: EPA has neither disclaimed §301 nor stopped invoking it.
• The negative reaches everything EPA published in the Federal Register, which is where a preamble limit would have to appear. It does not reach internal legal positions or litigation briefs, and the Quote is about rulemaking, so that gap is narrow.