MARPOL Annex II

MARPOL Annex II governs the control of pollution by noxious liquid substances (NLS) carried in bulk. Cargoes are categorised into four groups — X, Y, and Z — depending on their hazard to marine resources, human health, and the amenity of the sea. Category X substances present the greatest hazard and may not be discharged into the sea at all; Category Y and Z substances may only be discharged under specific conditions relating to distance from land, ship speed, and residue concentration. For an officer on a chemical tanker, Annex II is a central operational framework. The Cargo Record Book must record every loading, transfer, cleaning, and discharge operation. Prewash requirements — washing out tanks before discharge to port reception facilities — apply to many Category X cargoes. The ship must carry a Procedures and Arrangements Manual approved by the flag state, detailing how each cargo category is to be handled and cleaned. Chemical tankers operating under the IBC Code are subject to Annex II requirements for their specific cargoes. Port state control inspectors check the Cargo Record Book for completeness and consistency, and verify that the ship holds the appropriate certificates for the NLS categories it carries. Masters must ensure that no cargo is loaded or discharged without the correct entries being made, as MARPOL violations carry significant penalties in most port states.