On July 24, 2023, the U.S. Environmental Protection Agency (EPA) published a supplemental proposed rule titled ``National Emission Standards for Hazardous Air Pollutants: Primary Copper Smelting.'' The EPA is extending the comment period on this proposed rule that currently closes on September 7, 2023, by 15 days. The comment period will now remain open until September 22, 2023, to allow additional time for Tribal Nations and stakeholders to review and comment on the proposal.