The International Convention for the Prevention of Pollution from Ships, 1973 as modified by the Protocol of 1978, or "MARPOL 73/78" (short for "marine pollution") is one of the most important international marine environmental conventions.[2] It was developed by the International Maritime Organization with an objective to minimize pollution of the oceans and seas, including dumping, oil and air pollution.

MARPOL 73/78
International Convention for the Prevention of Pollution from Ships, 1973 as modified by the Protocol of 1978
MARPOL 73/78 ratifying states (as of April 2008)
Effective2 October 1983

The original MARPOL was signed on 17 February 1973, but did not come into force at the signing date. The current convention is a combination of 1973 Convention and the 1978 Protocol,[3] which entered into force on 2 October,1983. As of January 2018, 156 states are parties to the convention, being flag states of 99.42% of the world's shipping tonnage.[1]

All ships flagged under countries that are signatories to MARPOL are subject to its requirements, regardless of where they sail, and member nations are responsible for vessels registered on their national ship registry.[4]



MARPOL is divided into Annexes according to various categories of pollutants, each of which deals with the regulation of a particular group of ship emissions.

List of the MARPOL 73/78 Annexes
Annex Title Entry into force[1][5] No. of Contracting Parties/States[1]α % of the World Tonnage[1]β
Annex I Prevention of pollution by oil & oily water 2 October 1983
Annex II Control of pollution by noxious liquid substances in bulk 6 April 1987
Annex III Prevention of pollution by harmful substances carried by sea in packaged form 1 July 1992 138 97.59
Annex IV Pollution by sewage from ships 27 September 2003
Annex V Pollution by garbage from ships 31 December 1988
Annex VI Prevention of air pollution from ships 19 May 2005 72 94.70


As of 31 July 2013
Based on World Fleet Statistics as of 31 December 2012

Annex I


MARPOL Annex I came into force on 2 October 1983 and deals with the discharge of oil into the ocean environment.[6] It incorporates the oil discharge criteria prescribed in the 1969 amendments to the 1954 International Convention for the Prevention of Pollution of the Sea by Oil (OILPOL). It specifies tanker design features that are intended to minimize oil discharge into the ocean during ship operations and in case of accidents. It provides regulations with regard to the treatment of engine room bilge water (OWS) for all large commercial vessels and ballast and tank cleaning waste (ODME). It also introduces the concept of "special sea areas (PPSE)", which are considered to be at risk to pollution by oil. Discharge of oil within them has been completely outlawed, with a few minimal exceptions.[5]

The first half of MARPOL Annex I deals with engine room waste. There are various generations of technologies and equipment that have been developed to prevent waste such as oily water separators (OWS), oil content meters (OCM), and port reception facilities.[7]

The second part of the MARPOL Annex I has more to do with cleaning the cargo areas and tanks. Oil discharge monitoring equipment (ODME) is a very important technology mentioned in MARPOL Annex I that has greatly helped improve sanitation in these areas.[7]

The oil record book is another integral part of MARPOL Annex I, helping crew members log and keep track of oily wastewater discharges, among other things.

Annex II


MARPOL Annex II came into force on 2 October,1983. It details the discharge criteria for the elimination of pollution by noxious liquid substances carried in large quantities. It divides substances into and introduces detailed operational standards and measures. The discharge of pollutants is allowed only to reception facilities with certain concentrations and tions. No matter what, no discharge of residues containing pollutants is permitted within 12 nautical miles (22 kilometres) of the nearest land. Stricter restrictions apply to "special areas".[5]

Annex II covers the International Bulk Chemical Code (IBC Code) in conjunction with Chapter 7 of the SOLAS Convention. Previously, chemical tankers constructed before 1 July 1986 must comply with the requirements of the Code for the Construction and Equipment of Ships Carrying Dangerous Chemicals in Bulk (BCH Code).[8]

Annex III


MARPOL Annex III came into force on 1 July 1992. It contains general requirements for the standards on packing, marking, labeling, documentation, stowage, quantity subtraction, division and notifications for preventing pollution by harmful substances. The Annex is in line with the procedures detailed in the International Maritime Dangerous Goods (IMDG) Code, which has been expanded to include marine pollutants.[9] The amendments entered into force on 1 January,1991.[5]

Annex IV


Marpol Annex IV came into force on 27 September 2003. It introduces requirements to control pollution of the sea by sewage from ships.

Annex V

MARPOL 73-78 Instructions

MARPOL Annex V (Regulations for the Prevention of Pollution by Garbage from Ships) came into force on 31 December 1988. It specifies the distances from land in which materials may be disposed of and subdivides different types of garbage and marine debris. The requirements are much stricter in a number of "special areas" but perhaps the most prominent part of the Annex is the complete ban of dumping plastic into the ocean.[10]

Annex VI


MARPOL Annex VI came into force on 19 May 2005. It introduces requirements to regulate the air pollution being emitted by ships, including the emission of ozone-depleting substances, Nitrogen Oxides (NOx), Sulfur Oxides (SOx), Volatile Organic Compounds (VOCs) and shipboard incineration. It also establishes requirements for reception facilities for wastes from exhaust gas cleaning systems, incinerators, fuel oil quality, off-shore platforms and drilling rigs, and the establishment of Sulfur Emission Control Areas (SECAs).[5]

IMO 2020


As of 1st January, 2020, new emission standards are enforced for fuel oil used by ships, in a regulation known as IMO 2020. The global sulphur limit (outside SECA's) dropped from an allowed 3.5% sulphur in marine fuels to 0.5%. This will significantly improve the air quality in many populated coastal and port areas, which will prevent over 100,000 early deaths each year, and many more cases of asthma in these regions and cities.[11][12] Over 170 countries have signed on to the changes, including the United States.[13] This is expected to create massive changes for the shipping and oil industries, with major updates required to ships and the increased production of lower sulfur fuel.[14]

Bunker fuels used within an emission control zone (i.e. North Sea) must have a sulphur content level of less than 0.1% (1000ppm).

The IMO has worked on ensuring consistent implementation of the 0.5% sulphur limit in its Marine Environmental Protection Committee (MEPC) and its subcommittee on Pollution Prevention and Response (PPR). This has led to the development on several regulatory and practical measures (FONAR's, Carriage Ban, Ship Implementation Plan etc.) to enable any non-compliance to be detected, for example during port state controls (PSC's).[15]



MARPOL Annex VI amendments according with MEPC 176(58) came into force 1 July 2010.[16]

Amended Regulations 12 concerns control and record keeping of Ozone Depleting Substances.[17]

Amended Regulation 14[18] concerns mandatory fuel oil change over procedures for vessels entering or leaving SECA areas and FO sulphur limits.

MARPOL Annex V has been amended multiple times, changing different aspects of the original text.

MEPC.219(63) came into force on 2 March 2012 to generally prohibit the discharge of any garbage into the ocean, with the exception of food wastes, cargo residues, wash-water, and animal carcasses.[19] There are further provisions describing when and how to dispose of the acceptable wastes.

MEPC.220(63) came into force on 2 March 2012 to encourage the creation of a waste management plan on-board vessels.[20]

Implementation and enforcement


In order for IMO standards to be binding, they must first be ratified by a total number of member countries whose combined gross tonnage represents at least 50% of the world's gross tonnage, a process that can be lengthy. A system of tacit acceptance has therefore been put into place, whereby,if no objections are heard from a member state after a certain period has elapsed, it is assumed they have assented to the treaty.

All six Annexes have been ratified by the requisite number of nations; the most recent is Annex VI, which took effect in May 2005. The country where a ship is registered (Flag State) is responsible for certifying the ship's compliance with MARPOL's pollution prevention standards. Each signatory nation is responsible for enacting domestic laws to implement the convention and effectively pledges to comply with the convention, annexes, and related laws of other nations. In the United States, for example, the relevant implementation legislation is the Act to Prevent Pollution from Ships.

One of the difficulties in implementing MARPOL arises from the very international nature of maritime shipping. The country that the ship visits can conduct its own examination to verify a ship's compliance with international standards and can detain the ship if it finds significant noncompliance. When incidents occur outside such country's jurisdiction or jurisdiction cannot be determined, the country refers cases to flag states, in accordance with MARPOL. A 2000 US GAO report documented that even when referrals have been made, the response rate from flag states has been poor.[21]

On 1 January 2015, maritime shipping levels became legally subject to new MARPOL directives because the SECA (Sulphur Emission Controlled Areas) zone increased in size. This larger SECA zone will include the North Sea, Scandinavia, and parts of the English Channel. This area is set to include all of the Republic of Ireland's international waters in 2020 culminating in all of Western Europe's subjection to the MARPOL directive. This has proven controversial for shipping and ferry operators across Europe.

Concerns have been raised about the environmental damage moving back to the roads by some of the larger ferry operators that ship substantial amounts of freight and passenger traffic via these routes affected by IMO standards. They claim that MARPOL will drive up ferry costs for the consumer and freight forwarding companies pushing them back onto the European roadways as a financially more cost effective measure compared to increased ferry costs, thereby defeating the object of reducing water pollution.[22]

Enforcement of MARPOL Annex VI


Concerns have also been raised whether the emission regulation in MARPOL Annex VI, such as the 0.5% global sulphur limit, can be enforced on international waters by non-flag States, as some ships sail under a flag of convenience. It is believed that the United Nations Convention on the Law Of the Sea (UNCLOS) allows port States to assert jurisdiction over such violations of emission regulation (also of future regulations of GHG) when they occur on the high seas. Coastal States can assert jurisdiction over violations occurring within their waters, with certain exceptions pertaining to innocent passage and the right of transit passage. The special obligations for flag States and the broadened jurisdictions for coastal and port States, to enforce MARPOL (including Annex VI) are found within the special provisions of part XII of UNCLOS.[23]

See also



  1. ^ a b c d e "Status of Treaties" (PDF), IMO, 16 December 2019, archived from the original (PDF) on 28 May 2020, retrieved 31 December 2019
  2. ^ "What is MARPOL Convention? IMO Convention for the Prevention of Pollution from Ships".
  3. ^ "Chronology & Search". MAX1 Studies. Archived from the original on 4 March 2016. Retrieved 15 July 2015.
  4. ^ Copeland, Claudia (6 February 2008). "Cruise Ship Pollution: Background, Laws and Regulations, and Key Issues" (PDF). Congressional Research Service. Archived from the original (PDF) on 25 April 2013. This article incorporates text from this source, which is in the public domain
  5. ^ a b c d e "MARPOL73-78: Brief history - list of amendments to date and where to find them". MARPOL73-78: Brief history - list of amendments to date and where to find them. IMO. 2012. Retrieved 3 June 2015.
  6. ^ Law, Published with the Institute of Maritime; University, Southampton (9 December 2022). "The Ratification of Maritime Conventions". {{cite journal}}: Cite journal requires |journal= (help)
  7. ^ a b "International Convention for the Prevention of Pollution from Ships (MARPOL)". Archived from the original on 4 October 2019. Retrieved 23 July 2015.
  8. ^ "IBC Code". Archived from the original on 30 July 2019. Retrieved 2 July 2017.
  9. ^ Anish (23 August 2022). "What is International Maritime Dangerous Goods Code (IMDG)?". Marine Insight. Retrieved 30 June 2023.
  10. ^ "Garbage". Pollution Prevention. Archived from the original on 15 April 2018. Retrieved 14 April 2018.
  11. ^ Sofiev, Mikhail; Winebrake, James J.; Johansson, Lasse; Carr, Edward W.; Prank, Marje; Soares, Joana; Vira, Julius; Kouznetsov, Rostislav; Jalkanen, Jukka-Pekka; Corbett, James J. (6 February 2018). "Cleaner fuels for ships provide public health benefits with climate tradeoffs". Nature Communications. 9 (1): 406. Bibcode:2018NatCo...9..406S. doi:10.1038/s41467-017-02774-9. ISSN 2041-1723. PMC 5802819. PMID 29410475.
  12. ^ Corbett, James J.; Winebrake, James J.; Carr, Edward W. (12 August 2016). "Health Impacts Associated with Delay of MARPOL Global Sulphur Standards" (Document). Finnish Meteorological Institute.
  13. ^ Meredith, Sam (15 July 2019). "The 'biggest change in oil market history' is less than six months away". CNBC. Retrieved 19 November 2019.
  14. ^ Viens, Ashley (12 June 2019). "IMO 2020: The Big Shipping Shake-Up". Visual Capitalist. Retrieved 19 November 2019.
  15. ^ "Index of MEPC Resolutions and Guidelines related to MARPOL Annex VI", IMO, archived from the original on 9 August 2020, retrieved 4 October 2019
  16. ^ "MEPC 176(58)" (PDF). Archived from the original on 7 July 2009. Retrieved 7 February 2018.{{cite web}}: CS1 maint: bot: original URL status unknown (link)
  17. ^ "Regulations 12". Archived from the original on 22 May 2010.
  18. ^ "Regulation 14". Archived from the original on 22 May 2010.
  19. ^ "MEPC.219(63)" (PDF). Archived from the original (PDF) on 14 February 2020. Retrieved 14 April 2018.
  20. ^ "MEPC.220(63)" (PDF). Archived from the original (PDF) on 14 February 2020. Retrieved 14 April 2018.
  21. ^ Office, U. S. Government Accountability (7 March 2000). "Marine Pollution: Progress Made to Reduce Marine Pollution by Cruise Ships, but Important Issues Remain" (PDF) (RCED-00-48): 20. Archived (PDF) from the original on 6 March 2010. {{cite journal}}: Cite journal requires |journal= (help)
  22. ^ Jesper Jarl Fanø (2019). Enforcing International Maritime Legislation on Air Pollution through UNCLOS. Hart Publishing. ISBN 9781509927760