When evidence of a public health risk, including sources of infection and contamination, is detected on board and after required control measures have been satisfactorily completed; the SSC must record the evidence found and the control measures taken. Extension of the Ship Sanitation Control Exemption Certificate: when the inspection or control measures required cannot be carried out at a port and there is no evidence of infection or contamination, the competent authority may extend the validity of the certificate for a period of one month, allowing the ship to arrive at a port in which the inspection and any necessary control measures can be carried out and the new Ship Sanitation Control Certificate may be issued.