(a) Party means, for the purposes of this subpart:

(1) The Assistant Administrator or the Assistant Administrator's representative;

(2) A person who has notified the Assistant Administrator by specified dates of his or her intent to participate in the hearing pursuant to §§228.5 and 228.14(b).

(b) Witness means, for the purpose of this part, any person who submits written direct testimony on the proposed regulations. A person may be both a party and a witness.