29 CFR 1955.14: Ex parte communications.

(a) Except to the extent required for the disposition of ex parte matters, the administrative law judge shall not consult any interested person or party or their representative on any fact in issue or on the merits of any matter before him except upon notice and opportunity for all parties to participate.

(b)(1) Written or oral communications from interested persons outside the Department of Labor involving any substantive or procedural issues in a proceeding directed to the administrative law judge, the Secretary of Labor, the Assistant Secretary, the Associate Assistant Secretary for Regional Programs, the Solicitor of Labor, or the Associate Solicitor for Occupational Safety and Health, or their staffs shall be deemed ex parte communications and are not to be considered part of any record or the basis for any official decision, unless the communication is made by motion to the administrative law judge and served upon all the parties.

(2) To facilitate implementation of this requirement, the above-mentioned offices shall keep a log of such communications which shall be made available to the public and which may, by motion, be entered into the record.

(c) No employee or agent of the Department of Labor engaged in the investigation or presentation of the withdrawal proceeding governed by this part shall participate or advise in the initial or final decision, except as a witness or counsel in the proceeding.