The EPA is proposing to add requirements for sources to reclassify from major source status to area source status under the National Emission Standards for Hazardous Air Pollutants (NESHAP) program. The requirements of this proposal would apply to all sources that choose to reclassify, including any sources which have reclassified since January 25, 2018. The EPA is proposing that sources reclassifying from major source status to area source status under the NESHAP program must satisfy the following criteria: any permit limitations taken to reclassify from a major source of hazardous air pollutants (HAP) under the Clean Air Act to an area source of HAP must be federally enforceable, any such permit limitations must contain safeguards to prevent emission increases after reclassification beyond the applicable major source NESHAP requirements at time of reclassification, and reclassification will only become effective once a permit has been issued containing enforceable conditions reflecting the requirements proposed in this action and electronic notification has been submitted to the EPA. Additionally, we are proposing clarifications to reporting requirements and updating language regarding submittal of confidential business information. Comments must be received on or before November 13, 2023.