It is a mandatory requirement under MARPOL Annex V for shippers to declare whether a cargo is HME cargo or not. If a cargo is declared as HME cargo (a cargo that is Harmful to the Marine Environment), there could be difficulties and significant amount of costs to send the cargo residue and hold washings to port reception facilities. MARPOL Annex V strictly bans discharge of any amount of HME cargo residue and hold washings into the sea, anywhere including high seas.
Here are the 5 types of material linked to “HME cargo”:
