The question in a particular matter rests with that individual member. Each member should weigh carefully the question of his qualification with respect to any matter wherein he or any relatives or former business associates or clients are involved. He should disqualify himself in the event he obtained knowledge prior to becoming a member of the facts at issue before him in a quasi-judicial proceeding, or in other types of proceeding in any matter involving parties in whom he has any interest or relationship directly or indirectly. If an interested person suggests that a member should disqualify himself in a particular matter because of bias or prejudice, the member shall be the judge of his own qualification.