Ohio Rev. Code Ann. § 124.323

Employees shall be laid off in the order set forth in this section within the primary appointment categories of part-time probationary, part-time permanent, full-time probationary, and full-time permanent. Whenever a reduction in force is necessary within each of the primary appointment categories, first part-time probationary, then part-time permanent, then full-time probationary, and then full-time permanent employees shall be laid off.