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Administrator Zeldin Updates Sen. Sullivan on EPA's Diesel Exhaust Fluid Actions

May 1, 2026 · U.S. Environmental Protection Agency · 0:01:51

Embedded from the source channel — never re-uploaded. Watch on YouTube

What happened

Sen. Dan Sullivan asked EPA Administrator Lee Zeldin for an update on diesel exhaust fluid (DEF) rules, noting, as Sullivan stated it, that an Obama administration regulation effectively shuts down diesel engines at 12 degrees — a balmy day in Alaska — and that a hearing had shown the risk to lives and safety, not only in Alaska but anywhere with cold weather.

Zeldin replied that last August at the Iowa State Fair, alongside Small Business Administrator Kelly Loeffler, Secretary Brooke Rollins, and Sen. Joni Ernst, the EPA announced a significant reversal of the deratements through new EPA guidance. He said that in February the agency sent a demand letter for information to 14 engine manufacturers seeking their warranty data for future decisions, and issued right-to-repair guidance so farmers and others can repair their own equipment, as he stated it.

Zeldin added that the President recently announced new actions on DEF, that EPA guidance got rid of the DEF sensors so they are no longer required, and that the agency is moving to its 2027 NOx proposal, which, as he stated it, the EPA intends to use to completely eliminate all deratements. He also thanked Alaska’s haul truckers for feedback on filters gathered during a Fairbanks visit and said the agency will not forget them.

Why it matters

The exchange is the EPA’s progress report on one of the most-complained-about rules Zeldin says he inherited, moving the DEF fight from guidance toward a formal rulemaking that would end engine deratements outright.

Scoreboard watch

Flagged for the scoreboard editor: Zeldin stated the EPA intends to propose, as part of the upcoming 2027 NOx rulemaking, to remove DEF deratements entirely; no verdict is given here.

Sources: U.S. Environmental Protection Agency, “Administrator Zeldin on EPA\u2019s Incredible Progress on Diesel Exhaust Fluid with Sen. Dan Sullivan”, 2026-05-01 (official upload, embedded above; published 2026-05-01). Transcript via Supadata (private research store, paraphrased and attributed, not republished). All figures and characterizations as stated by the speakers.