43 CFR §4.414

1. (a)General procedures. Permission to file an interlocutory appeal is a two-step process, requiring a party to do both of the following:
   1. (1)File an application in accordance with § 4.122(d) asking the ALJ to certify an ALJ order, in whole or in part, for interlocutory appeal; and
   2. (2)Within 14 days of the ALJ's ruling on the application for certification, petition the Board in accordance with § 4.122(g) for permission to file an interlocutory appeal of the ALJ's order, in whole or in part.
2. (b)Permission from the Board. The Board will grant permission to file an interlocutory appeal under the following circumstances:
   1. (1)The ALJ grants certification, and the Board agrees that the ALJ's interlocutory ruling involves a controlling question of law about which there are substantial grounds for a difference of opinion and that an immediate appeal will materially advance the completion of the proceeding; or
   2. (2)The ALJ denies certification, and the Board determines that the ALJ abused their discretion in doing so.