Trump Rolls Back Biden-Era Copper Smelter Pollution Rules to Boost U.S. Mineral Security

President Donald Trump on Friday repealed a Biden-era air pollution rule that had set tougher emission limits for U.S. copper smelters, granting the industry a two-year exemption from compliance. The White House said the move aims to strengthen America’s mineral independence and relieve regulatory pressure on domestic producers.

The 2024 rule had required smelters to curb toxic emissions such as lead, arsenic, mercury, benzene, and dioxins under updated federal air standards. In reversing it, Trump argued that the regulation threatened the viability of an already “limited and strained” domestic copper industry, risking further plant closures and increased reliance on foreign processing.

The order applies specifically to Freeport-McMoRan’s Arizona smelter, one of only two operating in the country. Freeport praised the decision, calling it “a recognition of copper’s importance to national security” and an opportunity to reassess future regulatory approaches. Rio Tinto’s Utah facility remains unaffected, having already invested heavily in emissions-capture technologies.

The rollback follows Trump’s executive order earlier this year designating copper as a critical mineral for defense, infrastructure, and clean energy technologies. After a national security review, the administration imposed a 50% tariff on certain imported copper and directed that more U.S.-produced scrap copper be sold domestically.

Environmental groups condemned the decision, saying it prioritizes industrial interests over public health and climate commitments.

Weaker federal pollution rules for copper smelters don't reduce corporate liability - they just push it into state permitting, community litigation and international scrutiny under IRMA and CSRD supply-chain diligence. Our sustainability-due-diligence and supply-chain-and-operations teams help metal producers and their downstream buyers evaluate what this shift means for responsible-sourcing exposure and disclosure.