21 CFR §12.89

1. (a)A nonparty participant may—
   1. (1)Attend all conferences (including the prehearing conference), oral proceedings, and arguments;
   2. (2)Submit written testimony and documentary evidence for inclusion in the record;
   3. (3)File written objections, briefs, and other pleadings; and
   4. (4)Present oral argument.
2. (b)A nonparty participant may not—
   1. (1)Submit written interrogatories; and
   2. (2)Conduct cross-examination.
3. (c)A person whose petition is the subject of the hearing has the same right as a party.
4. (d)A nonparty participant will be permitted additional rights if the presiding officer concludes that the participant's interests would not be adequately protected otherwise or that broader participation is required for a full and true disclosure of the facts, but the rights of a nonparty participant may not exceed the rights of a party.