12.75—Disqualification of presiding officer.
        
        (a) 
         A participant may request the presiding officer to disqualify himself/herself and withdraw from the proceeding. The ruling on any such request may be appealed in accordance with  § 12.97(b).
    
    
        
        (b) 
         A presiding officer who is aware of grounds for disqualification shall withdraw from the proceeding.