The USEPA is approving revisions to the Ohio State Implementation Plan (SIP) adopted by the Ohio Environmental Protection Agency (OEPA) on March 15, 1993, and December 30, 1994. The OEPA submitted these revisions to the USEPA on June 7, 1993, and February 17, 1995. The revisions concern Ohio Administrative Code (OAC) Chapter 3745-21, ``Carbon Monoxide, Photochemically Reactive Materials, [[Page 15236]] Hydrocarbons, and Related Materials Standards.'' The USEPA has evaluated the revisions to Rules 01, 04, 09, and 10 and is approving the requested revisions. The USEPA's action is based upon a revision request which was submitted by the State to satisfy the requirements of the Clean Air Act.