The IHR (2005) Ship Sanitation Certificates (SSCs) are of particular importance for the prevention and control of public health risks on board ships on international voyages. They provide internationally recognized documentation regarding the sanitary conditions of a ship, while reducing the need for further and more frequent inspections of the ship during the period for which the certificate is valid (but with options for additional inspections under certain limited circumstances).This handbook is to be used as reference material for port health officers, regulators, ship operators and other competent authorities in charge of implementing the IHR (2005) at ports and on ships. The handbook is based on the IHR (2005) provisions regarding ship inspection and issue of SSCs. They provide guidance for preparing and performing the inspection, completing the certificates and applying public health measures within the framework of the IHR (2005).This handbook also addresses environmental issues that may constitute public health risks, such as the discharge by ships of sewage, waste and ballast water. Harmful contamination (other than microbial contamination), such as from radio-nuclear sources, could also be found on ships.Throughout this book, references are provided on occupational health issues for ships crews or other events that affect public health, and inspections applicable to items of IHR Annex 3. References are also provided on the prevention and control of events that may constitute a public health event of international concern (as defined in the IHR). "The Guide to Ship Sanitation" (WHO, 2011) and the "International Medical Guide for Ships" (WHO, 2007) are companion volumes to this handbook, oriented towards preventive health and curative health, respectively, on board ships."