Ohio Revised Code Title XXXV. Elections § 3505.29

From the time the ballot box is opened and the count of ballots begun until the ballots are counted and certificates of votes cast are made out, signed, certified and given to the voting location manager for delivery to the headquarters of the board of elections, the precinct election officials in each precinct shall not separate, nor shall a precinct election official leave the polling place except from unavoidable necessity. In cases of illness or unavoidable necessity, the board may substitute another qualified person for any precinct official so incapacitated.