12.—(1) The Scottish Ministers may by notice served on the occupier of any premises (other than infected premises) investigated under article 11 declare that they are to be regarded as two or more separate production units if the Chief Veterinary Officer (Scotland) advises at the time of the veterinary inquiry that in the opinion of the Chief Veterinary Officer (Scotland)–
(a)the structure, including the administration and size of the premises, allow, for each separate unit, a complete separation of housing and keeping for their susceptible animals, including separate air space;
(b)the operations on each separate unit, and in particular stable and pasture management, milking, feeding, and removal of dung or manure are completely separated and carried out by different personnel;
(c)the machinery, non-susceptible working animals, equipment, installations, instruments and disinfection facilities used in each separate unit are completely separate; and
(d)each of those sub paragraphs has applied continuously for at least–
(i)28 days immediately prior to the date of the inquiry, if only bovine animals or swine have been on the premises within that period; or
(ii)42 days immediately prior to that date in any other case.
(2) A declaration under paragraph (1) shall identify, and designate the boundaries of each separate unit and shall declare every separate unit which is free of disease to be a free unit.
(3) A unit shall cease to be a free unit on–
(a)variation of the notice declaring it such that it is no longer declared to be a free unit, or
(b)revocation of the notice declaring it.