EPA is approving miscellaneous revisions to the Tennessee State Implementation Plan (SIP) regarding prevention of significant deterioration (PSD) and volatile organic compounds (VOC). The revisions to the PSD regulation add an additional supplement to the EPA ``Guideline on Air Quality Models.'' The revisions to the VOC regulation make minor changes to the regulation for the manufacture of high-density polyethylene, polypropylene and polystyrene resins and to the regulation containing test methods and compliance procedures for VOC sources.