International Convention for the Prevention of Pollution from Ships (MARPOL)

Adoption: 1973 (Convention), 1978 (1978 Protocol), 1997 (Protocol – Annex VI); Entry into force: 2 October 1983 (Annexes I and II).

​The MARPOL Convention is the main international convention covering prevention of pollution of the marine environment by ships from operational or accidental causes. It is a combination of two treaties adopted in 1973 and 1978 respectively and also includes the Protocol of 1997 (Annex VI).  It has been updated by amendments through the years.


The International Convention for the Prevention of Pollution from Ships (MARPOL) was adopted on 2 November 1973 at IMO and covered pollution by oil, chemicals, harmful substances in packaged form, sewage and garbage. The Protocol of 1978 relating to the 1973 International Convention for the Prevention of Pollution from Ships (1978 MARPOL Protocol) was adopted at a Conference on Tanker Safety and Pollution Prevention in February 1978 held in response to a spate of tanker accidents in 1976-1977. As the 1973 MARPOL Convention had not yet entered into force, the 1978 MARPOL Protocol absorbed the parent Convention. The combined instrument is referred to as the International Convention for the Prevention of Marine Pollution from Ships, 1973, as modified by the Protocol of 1978 relating thereto (MARPOL 73/78), and it entered into force on 2 October 1983 (Annexes I and II). In 1997 a Protocol was adopted to add a new Annex VI.
The Convention includes regulations aimed at preventing and minimizing pollution from ships – both accidental pollution and that from routine operations – and currently includes six technical Annexes. special Areas with strict controls on operational discharges are included in most Annexes:
Annex I  Regulations for the Prevention of Pollution by Oil (entered into force 2 October 1983)
Covers prevention of pollution by oil from operational measures as well as from accidental discharges. The 1992 amendments to Annex I made it mandatory for new oil tankers to have double hulls and brought in a phase-in schedule for existing tankers to fit double hulls, which was subsequently revised in 2001 and 2003.

Annex II  Regulations for the Control of  Pollution by Noxious Liquid Substances in Bulk  (entered into force 2 October 1983)

Annex II details the discharge criteria and measures for the control of pollution by noxious liquid substances carried in bulk.
Some 250 substances were evaluated and included in the list appended to the Convention.  The discharge of their residues is allowed only to reception facilities until certain concentrations and conditions (which vary with the category of substances) are complied with.
In any case, no discharge of residues containing noxious substances is permitted within 12 miles of the nearest land.  More stringent restrictions applied to the Baltic and Black Sea areas.
Annex III Prevention of Pollution by Harmful Substances Carried by Sea in Packaged Form (entered into force 1 July 1992)
Annex III contains general requirements for the issuing of detailed standards on packing, marking, labelling, documentation, stowage, quantity limitations, exceptions and notifications for preventing pollution by harmful substances. The International Maritime Dangerous Goods (IMDG) Code has, since 1991, included marine pollutants.
Annex IV Prevention of Pollution by Sewage from Ships  (entered into force 27 September 2003) 
Annex IV contains requirements to control pollution of the sea by sewage.
Annex V Prevention of Pollution by Garbage from Ships (entered into force 31 December 1988) 
This deals with different types of garbage and specifies the distances from land and the manner in which they may be disposed of.  The requirements are much stricter in a number of “special areas” but perhaps the most important feature of the Annex is the complete ban imposed on the dumping into the sea of all forms of plastic.


Annex VI Prevention of  Air Pollution from Ships (entered into force 19 May 2005)

The regulations in this annex set limits on sulphur oxide and nitrogen oxide emissions from ship exhausts as well as particulate matter and prohibit deliberate emissions of ozone depleting substances. Emission control areas set more stringent standards.