29 CFR §1911.16

1. (a)To regulate the course of the proceedings;
2. (b)To dispose of procedural requests, objections, and comparable matters;
3. (c)To confine the presentations to the issues specified in the notice of hearing, or, where no issues are specified, to matters pertinent to the proposed rule;
4. (d)To regulate the conduct of those present at the hearing by appropriate means;
5. (e)In his discretion, to permit cross- examination of any witness;
6. (f)To take official notice of material facts not appearing in the evidence in the record, so long as parties are entitled, on timely request, to an opportunity to show the contrary; and
7. (g)In his discretion, to keep the record open for a reasonable, stated time to receive written recommendations, and supporting reasons, and additional data, views, and arguments from any person who has participated in the oral proceeding.