Any person wishing to participate in any proceeding commenced pursuant to any notice by the Administrator of intention to hold a hearing, shall file with the hearing clerk, within the time set by the Administrator in the notice (in no case less than 30 days from the date of the notice), a written response to the statement of issues which shall include the position and interest of such person with respect thereto. If any such person is a registrant or an applicant for registration, he shall also file the registration number of the pesticide, if applicable, a copy of the currently accepted and/or proposed labeling and a list of the currently registered or proposed uses of said pesticide.