Ill. Admin. Code tit. 2, § 1520.80 – Appointment and Disqualification of Administrative Law Judges

a) In appointing an administrative law judge, the Commission shall inquire as to any personal or pecuniary interest or relationship the prospective appointee may have with respect to the complainant or respondent and shall appoint no administrative law judge who appears to the Commission to be biased for or against any party or who has a conflict of interest.
b) A complainant or respondent who has reason to believe the administrative law judge should be disqualified on the basis of bias or conflict of interest may object to the appointment on that basis and ask that the administrative law judge be disqualified any time before evidence is taken, but must do so at or before the prelimary conference if the party is aware of disqualifying facts at that time. If the administrative law judge does not disqualify himself in response to the objection, the objector may present facts to the Commission on the issue of bias or conflict of interest at the beginning of the meeting or hearing, and the question shall be resolved before further proceedings. Failure to object before the taking of evidence shall constitute a waiver of the objection.
c) If the complainant or respondent discovers facts that would form a basis for objection to the appointment of an administrative law judge for bias or conflict of interest only after the taking of evidence begins, the party shall move for disqualification within three business days of the discovery, but in no event after the final decision of the Commission, or the issue is waived.