Within five days after receipt of the notice described in § 125.39 the applicant or holder may request disqualification of any member of the Hearing Board on the grounds of personal bias or other cause. The request shall be accompanied by an affidavit setting forth in detail the facts alleged to constitute grounds for disqualification. The affidavit may be supplemented by an oral presentation if desired. If after due consideration the Chairman believes a challenged member is qualified notwithstanding the challenge, he shall notify the person who made the challenge and arrange to proceed with the hearing. If the person who made the challenge takes exception to the ruling of the Chairman, the exception and data relating to the claim of disqualification shall be made a matter of record. If the Chairman finds that there is reasonable ground for disqualification he shall furnish the person who made the challenge with the name of an alternate in lieu of the challenged member and arrange to proceed with the hearing. In the event the Chairman is challenged, he shall forthwith notify the Commandant, furnishing the grounds for the claim of disqualification, and the Commandant shall act upon the challenge in accordance with the foregoing procedure. In addition to the right to challenge for cause, a person who has requested a hearing shall have two peremptory challenges, one challenge for the management member and one challenge for the labor member of the Hearing Board. Should the management member be so challenged, the person who made the challenge may elect to have the management member replaced by another management member or by a member not representing either management or labor; if the member peremptorily challenged represents labor, the person who made the challenge may elect to have the labor member replaced by another labor member or by a member not representing either management or labor.