The U.S. Environmental Protection Agency (EPA) is proposing amendments to the National Emission Standards for Hazardous Air Pollutants (NESHAP) for the Carbon Black Production major source category. The proposal addresses the results of the residual risk and technology review (RTR) for this source category as required under the Clean Air Act (CAA). The proposed amendments address hazardous air pollutant (HAP) emissions that occur after the main unit filter of a carbon black production unit, as well as emissions from boilers and process heaters.

The Environmental Protection Agency (EPA) is adopting greenhouse gas (GHG) emission standards applicable to certain classes of engines used by certain civil subsonic jet airplanes with a maximum takeoff mass greater than 5,700 kilograms and by certain civil larger subsonic propeller-driven airplanes with turboprop engines having a maximum takeoff mass greater than 8,618 kilograms.

This proposal presents the results of the U.S. Environmental Protection Agency's (EPA's) residual risk and technology review (RTR) for the National Emission Standards for the Hazardous Air Pollutants (NESHAP) for Primary Magnesium Refining, as required under the Clean Air Act (CAA). Based on the results of the risk review, the EPA is proposing that risks from emissions of air toxics from this source category are acceptable and that after removing the exemptions for startup, shutdown, and malfunction (SSM), the NESHAP provides an ample margin of safety.

The Environmental Protection Agency (EPA) is proposing to approve in part and to disapprove in part the state implementation plan (SIP) revision submitted by the State of Arizona to meet Clean Air Act (CAA or ``Act'') requirements for the 1987 PM<INF>10</INF> national ambient air quality standards (NAAQS or ``standard'') in the West Pinal County PM<INF>10</INF> nonattainment area.