40 CFR §178.20

1. (a)On or before the 60th day after the date of publication in the Federal Register of an order under part 180 of this chapter establishing, modifying, or revoking a regulation, or denying all or any portion of a petition, a person adversely affected by such order or petition denial may submit, in accordance with § 178.25, one or more written objections to the order (or to the action that is the subject of the order).
2. (b)A person may include with any such objection a written request for an evidentiary hearing on such objection in accordance with § 178.27
3. (c)A person who submits objections need not request a hearing. For instance, if the person's objections are of a purely legal or policy nature, a hearing request would be inappropriate; the purpose of an evidentiary hearing is to resolve factual disputes. The Administrator will rule on the objections, whether or not a hearing is requested.
4. (d)As a matter of discretion, the Administrator may order a hearing on an objection even though no person has requested a hearing.