The International Convention for the Prevention of Pollution from Ships, 1973 as modified by the Protocol of 1978 (MARPOL 73/78, MARPOL is short for marine pollution and 73/78 short for the years 1973 and 1978) is one of the most important international marine environmental conventions. It was developed by the International Maritime Organization in an effort to minimize pollution of the oceans and seas, including dumping, oil and air pollution. The objective of this convention is to preserve the marine environment in an attempt to completely eliminate pollution by oil and other harmful substances and to minimize accidental spillage of such substances.

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,[1] 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.[2]

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.[3]


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[4][5] No. of Contracting Parties/States[4]α  % of the World Tonnage[4]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 discharge of oil into the ocean environment. 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 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.[6]

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.[6]

The Oil Record Book is another integral part of MARPOL Annex I. The Oil Record Book helps crew members log and keep track of oily waste water discharges among other things.

Annex II

MARPOL Annex II came into force on 6 April 1987. 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 conditions. No matter what, no discharge of residues containing pollutants is permitted within 12 miles 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).[7]

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. 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.[5]

Annex V

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.[5]

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), Sulphur 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, for off-shore platforms and drilling rigs and for the establishment of SOx Emission Control Areas (SECAs).[5]


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

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

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

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.[8]

On January 1, 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.[9]

See also


  1. ^ "Chronology & Search". MAX1 Studies. Retrieved 2015-07-15. 
  2. ^ http://www.imo.org/en/About/Conventions/StatusOfConventions/Documents/StatusOfTreaties.pdf
  3. ^ Copeland, Claudia. "Cruise Ship Pollution: Background, Laws and Regulations, and Key Issues" (Order Code RL32450). Congressional Research Service (Updated 6 February 2008). This article incorporates text from this source, which is in the public domain.
  4. ^ a b c Summary of Status of Conventions Archived 1 May 2014 at the Portuguese Web Archive, www.imo.org
  5. ^ a b c d e f g "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. ^ a b "International Convention for the Prevention of Pollution from Ships (MARPOL)". www.imo.org. Retrieved 2015-07-23. 
  7. ^ "IBC Code". www.imo.org. Retrieved 2 July 2017. 
  8. ^ Office, U. S. Government Accountability (March 7, 2000). "Marine Pollution: Progress Made to Reduce Marine Pollution by Cruise Ships, but Important Issues Remain" (PDF) (RCED-00-48): 20. 

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