27 C.F.R. § 71.96
An administrative law judge shall, at any time, withdraw from any proceeding if he or she deems him or herself disqualified; and upon the filing in good faith by the applicant or respondent, or by the attorney for the Government, of a timely and sufficient affidavit of facts showing personal bias or otherwise warranting the disqualification of any administrative law judge, the Administrator shall upon appeal as provided in § 71.115 , if the administrative law judge fails to disqualify him or herself, determine the matter as a part of the record and decision in the proceeding. If the Administrator decides the administrative law judge should have declared him or herself disqualified, the Administrator will remand the record for hearing de novo before another administrative law judge. If the Administrator should decide against the disqualification of the administrative law judge, the proceeding will be reviewed on its merits.
27 C.F.R. §71.96