All notices of intention to cancel a registration, all notices of intention to change a classification, and all denials of registrations, all together with the reasons (including the factual basis therefor), and all notices of intention by the Administrator to hold a hearing, together with the statement of issues as provided by §164.20(b) shall be sent to the registrant or applicant by registered or certified mail (return receipt requested), and published by appropriate announcement in the Federal Register by the Administrator. The Administrative Law Judge shall cause to be published in the Federal Register by appropriate announcement, a notice of the filing of any objections, pursuant to §164.20(b) or responses pursuant to §164.24, and a notice of the public hearing as provided by §164.80 et seq. Said notice of public hearing shall designate the place where the hearing will be held and specify the time when the hearing will commence. The hearing shall convene at the place and time announced in the notice, unless amended by subsequent notice published in the Federal Register, but thereafter it may be moved to a different place and may be continued from day to day or recessed to a later day without other notice than announcement thereof at the hearing.