MARPOL is the international convention that established rules for preventing oil pollution from ships, adopted in its original form in 1973.
The convention's full name is the International Convention for the Prevention of Pollution from Ships. Its oil-pollution provisions regulate discharges, require equipment and recordkeeping, and establish standards for ships carrying oil and other harmful substances.
The framework was strengthened by the 1978 protocol adopted after a series of tanker accidents. Because the combined instrument is commonly called MARPOL 73/78, dates can cause confusion: the original convention was adopted in 1973, while the protocol was adopted in 1978.
MARPOL is broader than oil alone. Its annexes cover oil, noxious liquid substances, harmful substances in packaged form, sewage, garbage and air pollution from ships. SOLAS, by contrast, focuses mainly on maritime safety.