Any party to the adversary adjudication other than the applicant and the Commission investigative attorney may file comments on an application within 30 days after it is served or on an answer within 15 days after it is served. A commenting party may not participate further in proceedings on the application unless the presiding officer determines that the public interest requires such participation in order to permit full exploration of matters raised in the comments.
19 C.F.R. § 212.23