2020: Cleaner shipping for cleaner air

Global limit on sulphur in ships’ fuel oil reduced from 01 January 2020

A global regulation that will substantially reduce harmful sulphur oxide (SOx) emissions from ships comes into effect from 1 January 2020, bringing significant benefits for both human health and the environment.  

From 1 January 2020 the global upper limit on the sulphur content of ships’ fuel oil will be reduced to 0.50% (from 3.50%). Known as “IMO 2020”, the reduced limit is mandatory for all ships operating outside certain designated Emission Control Areas*, where the limit is already 0.10%.

The new limit will mean a 77% drop in overall SOx emissions from ships, equivalent to an annual reduction of approximately 8.5 million metric tonnes of SOx. Particulate matter – tiny harmful particles which form when fuel is burnt – will also be reduced.

As a result, reductions in stroke, asthma, lung cancer, cardiovascular and pulmonary diseases are expected. Cutting sulphur emissions from ships will also help prevent acid rain and ocean acidification, benefitting crops, forests and aquatic species.

The new limit is part of the International Convention for the Prevention of Pollution form ships (MARPOL), a key environmental treaty under the auspices of the International Maritime Organization (IMO) – the United Nations specialized agency responsible for developing and adopting standards for preventing pollution from ships, as well as shipping safety and efficiency, and maritime security. 

The decision to cut the global limit for sulphur in ships fuel oil to 0.50% was made in 2008 and confirmed again in October 2016.

An immense amount of preparatory work has been undertaken by IMO and industry stakeholders to ensure the changeover goes smoothly. IMO has issued a series of guidelines to help the shipping sector and its Member States to prepare, including ship implementation planning guidance (addressing issues such as risk assessment for new fuels and tank cleaning) and port State control guidelines.

IMO Secretary-General Kitack Lim said, “For the past three years, IMO Member States, the shipping industry and fuel oil suppliers have been working tirelessly to prepare for this major change in the sulphur content of ships’ fuel oil. I am confident that the benefits will soon be felt and that implementation will be smooth.”

He added, “I am very appreciative of all the efforts made by refineries, shipowners, seafarers, industry organizations and others in preparing for this hugely important change – which will have significant positive benefits for human health and the environment.”

To support smooth implementation, the IMO Secretariat has set up a dedicated hotline email address for any queries from Member States and the shipping industry as the regulation comes into effect.

To supply compliant fuel oil, refineries may blend fuel oils with a higher and lower sulphur content. Additives may be used to enhance other properties, such as lubricity. Ships may also use different fuels, with low or even zero sulphur – for example, liquefied natural gas, or biofuels. However, mixture and co-mingling of different fuels are not recommended on board the ship . Shipowners should refer to the relevant  International Standardization Organization (ISO) standards (ISO 8217 and ISO/PAS 23263:2019). Shipowners should test compatibility, stability and other relevant characters of compliant fuels to be used.

Limiting air pollutants by installing exhaust gas cleaning systems, also known as “scrubbers”, is accepted if flag States approve as an alternative means to meet the sulphur limit requirement. Scrubbers remove sulphur oxides from the ship’s engine and boiler exhaust gases, enabling ships fitted with them to continue to use heavy fuel oil, in accordance with IMO Guidelines.

*Baltic Sea; North Sea; North American area; United States Caribbean Sea area


  • IMO web page on Sulphur 2020 answers frequently asked questions and includes an IMO leaflet (download here) which outlines the requirement, answers the most frequently asked questions about the rule and provides a list of the IMO instruments supporting implementation, best practice guidance, port State control and sampling guidelines and others.
  • IMO has published a compilation of all related guidance, best practices and so on, as a single IMO publication (hard copy and electronic formats). (IMO 2020: Consistent Implementation of MARPOL Annex VI, 2019 Edition I666E,  Price £22,  ISBN 978-92-801-17189) .
  • Presentations from the IMO symposium on sulphur 2020 and alternative fuels can be downloaded here
  • IMO 2020 ICS Guidance on compliance for shipping companies and crews
  • Joint Industry Guidance on supply and use of 0.50% sulphur marine fuel 
  • INTERTANKO 2020 Practical Guide 
  • A Videotel training package is free to download and includes video information on the regulations and how to comply. Download:  https://landing.videotel.com/sulphur2020
  •  An open source free to access e-learning course is being developed with Videotel through the joint industry project, for free use by seafarers and others. The course will offer three modules and is expected to be available soon. 
  • CIMAC Guideline: Marine fuel handling in connection to stability and compatibility”, issued by the International Council of Combustion Engines (CIMAC).

The IMO 2020 publication, including all the IMO guidelines and guidance documents, can be purchased here.

Sulphur 2020 – Five key changes

5 changes – Sulphur 2020 – infographic web

Source: IMO

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