IOPP stands for International Oil Pollution Prevention. It's most commonly associated with a certificate issued to ships.
The IOPP Certificate is an International Oil Pollution Prevention Certificate issued under regulation 7 of Annex I of the International Convention for the Prevention of Pollution from Ships, 1973, as modified by the Protocol of 1978 relating thereto (MARPOL). This certificate verifies that a ship's construction and equipment meet the requirements for preventing oil pollution as defined in MARPOL Annex I. In essence, it confirms the vessel's compliance with international standards designed to protect the marine environment from oil spills.
