The MARPOL Annex V convention is a key international agreement for preventing marine pollution from ships. It requires that residues of solid bulk cargoes be managed based on whether they are classified as Harmful to the Marine Environment (HME) or non-HME.

A cargo is considered HME if it meets any of the seven criteria from the UN GHS, which relate to a substance's potential for aquatic toxicity, carcinogenicity, or other long-term environmental and health risks. This classification is crucial, as HME residues must be disposed of at a port facility, while non-HME residues can be discharged at sea under specific conditions. To ensure compliance, the IMSBC Code now specifically requires shippers to declare if a cargo is HME, making proper classification more important than ever for environmental safety.