Section 25(7)(B) in The Indian Port Health Rules, 1955
(B)Any unloading shall be carried out under the control of the Health Officer, who shall take all measures which, in his opinion, are necessary to prevent the infection of the staff engaged on this work. The staff so engaged may, at the discretion of the Health Officer, be subjected to isolation or to surveillance for a period not exceeding five days from the time when they have ceased to work at the unloading of the ship.