Section 57(4)(a) in The Indian Port Health Rules, 1955
(a)If the port is approved for the purpose of issuing Deratting Certificate, the Health Officer may derat the ship or cause the deratting to be done under his direction and control. He shall decide in each case the technique which should be employed to secure the extermination of rodents on the ship. Deratting shall be carried out so as to avoid as far as possible damage to the ship and to any cargo and shall not take longer than is absolutely necessary. Wherever possible deratting shall be done when the holds are empty. When deratting has been satisfactorily completed, the Health Officer shall issue a Deratting Certificate.