On 1 January 2020, a new limit on the sulphur content in the fuel oil used on board ships came into force, marking a significant milestone to improve air quality, preserve the environment and protect human health.
Known as “IMO 2020”, the rule limits the sulphur in the fuel oil used on board ships operating outside designated emission control areas to 0.50% m/m (mass by mass) – a significant reduction from the previous limit of 3.5%. Within specific designated emission control areas the limits were already stricter (0.10%). This new limit was made compulsory following an amendment to Annex VI of the International Convention for the Prevention of Pollution from Ships (MARPOL).
The resulting reduction in sulphur oxide (SOx) emissions from ships is having major health and environmental benefits for the world, particularly for populations living close to ports and coasts. Sulphur oxides are harmful to human health, causing respiratory, cardiovascular and lung disease. Once released in the atmosphere, SOx can lead to acid rain, which impacts crops, forests and aquatic species and contributes to the acidification of the oceans.
Before the entry into force of the new limit, most ships were using heavy fuel oil. Derived as a residue from crude oil distillation, heavy fuel oil had a much higher sulphur content which, following combustion in the engine, ended up in ships’ emissions. Now, the vast majority of ships are using very low sulphur fuel oil (VLSFO) to comply with the new limit, and no safety issues have to date been reported to IMO.
IMO 2020 – five key changes
Below you will find answers to some of the frequently asked questions about the sulphur limit.
1. How significant is the reduction in sulphur oxides emissions?
We have seen a substantial cut in the limit for sulphur content of fuel oil for ships operated outside designated emission control areas: from 3.50% m/m (mass by mass) to 0.50% m/m.
There is an even stricter limit of 0.10% m/m in effect in emission control areas (ECAS) which have been established by IMO. The four ECAS are: the Baltic Sea area; the North Sea area; the North American area (covering designated coastal areas off the United States and Canada); and the United States Caribbean Sea area (around Puerto Rico and the United States Virgin Islands).
Countries bordering the Mediterranean Sea are currently considering the possibility of applying to designate the Mediterranean Sea or parts thereof as an ECA (click here to learn more).
2. What are the impacts of the new limit on human health?
Simply put, limiting sulphur oxides emissions from ships reduces air pollution as well as particulate matter, which are tiny harmful particles which form when fuel is burnt.
The new limit was forecast to lead to a 77% drop in overall sulphur oxide emissions from ships – a reduction equivalent to 8.5 million metric tonnes of SOx. Sulphur oxides are linked to asthma, pulmonary, cardiovascular and respiratory diseases. Reducing these harmful emissions will therefore improve the health of populations, especially those living near ports and coasts, and help prevent premature deaths.
A study on the human health impacts of SOx emissions from ships, submitted to IMO’s Marine Environment Protection Committee (MEPC) in 2016 by Finland, estimated that by not reducing the SOx limit for ships from 2020, the air pollution from ships would contribute to more than 570,000 additional premature deaths worldwide between 2020-2025.
IMO 2020 – A Breath of Fresh Air – download the infographic (PDF) by clicking on the image
3. What must ships do to comply with the new IMO regulations?
The IMO MARPOL regulations limit the sulphur content in fuel oil. This means ships must use fuel oil which is inherently low enough in sulphur, or install an appropriate exhaust “alternative” method, in order to meet IMO requirements.
Refineries may blend fuel oil with a high (non-compliant) sulphur content with fuel oil with a sulphur content lower than the required sulphur content to achieve a compliant fuel oil. Additives may be added to enhance other properties, such as lubricity.
Some ships limit the air pollutants by installing exhaust gas cleaning systems, also known as “scrubbers”. This is accepted by flag States as an alternative means to meet the sulphur limit requirement. These scrubbers are designed to remove sulphur oxides from the ship’s engine and boiler exhaust gases. A ship fitted with a scrubber can use heavy fuel oil, since the sulphur oxides emissions will be reduced to a level equivalent to the required fuel oil sulphur limit. By mid-July 2020, some 2,359 systems had formally been reported to IMO as an approved “equivalent method” by Administrations (flag States).
Ships can have engines which use alternative fuels, which may contain low or zero sulphur, for example liquefied natural gas or biofuels.
4. What is IMO doing to ensure compliance with the 0.50% limit?
Monitoring compliance and enforcing the new limit falls under the remit of Governments and national authorities of Member States that are Parties to MARPOL Annex VI. Flag States (the State of registry of a ship) and port States have rights and responsibilities to enforce compliance. IMO has adopted 2019 Guidelines for port State control under MARPOL Annex VI Chapter 3 (download here).
Ahead of the entry into force of the new limit, on 1 January 2020, IMO worked with Member States as well as industry (including the shipping industry and the bunker supply and refining industry) to identify and mitigate transitional issues so that ships may meet the new requirement.
This work included developing guidance and standardised forms for reporting fuel oil non availability if a ship cannot obtain compliant fuel oil, as well as considering verification and control issues.
In October 2018, IMO’s Marine Environment Protection Committee (MEPC) adopted a MARPOL amendment to prohibit the carriage of non-compliant fuel oil for combustion purposes for propulsion or operation on board a ship – unless the ship has an exhaust gas cleaning system (“scrubber”) fitted. The amendment entered into force in March 2020 and is intended as an additional measure to support consistent implementation and compliance and provide a means for effective enforcement by States, particularly port State control.
A set of guidelines for the consistent implementation of the MARPOL regulation was developed by IMO and issued by the MEPC.
5. Are new fuels being used to meet the 2020 limit?
Yes, new blends of fuel oil for ships have been developed. For example, a gas oil, with a very low sulphur content can be blended with heavy fuel oil to lower its sulphur content.
Ships can also choose to switch to a different fuel altogether. Or they may continue to purchase heavy fuel oil, but install ”scrubbers” to reduce the output of SOx in order to levels that ensure compliance with the requirement.
Of course, some ships were already using low sulphur fuel oil to meet the even more stringent limits of 0.10% m/m when trading in the established emission control areas (ECAS). So those fuel oil blends suitable for ECAS also meet the 0.50% m/m limit.
6. Are low sulphur blend fuel oils safe? Can new low sulphur fuels cause problems for a ship’s engine?
All fuel oil for combustion purposes on a ship must meet required fuel oil quality standards, as set out in IMO MARPOL Annex VI (regulation 18.3). For example, the fuel oil must not include any added substance or chemical waste that jeopardizes the safety of ships or adversely affects the performance of the machinery.
Through 2020, and into 2021 to date, IMO has not received any reports of safety issues linked to VLSFO.
Nonetheless, during 2020, an IMO correspondence group was established to consider fuel oil safety issues in general and consider the need for further mandatory requirements to ensure fuel oil supplied meets the required standards and required quality. The report of the group (MSC 102/6) is available on IMODOCS). The report will be discussed at the next IMO Maritime Safety Committee (MSC) session, MSC 103 in May 2021.
Prior to that meeting, the Sub-Committee on Prevention of Pollution from Ships (PPR 8, schedule to meet in remote session 22-26 March 2021) will further consider VLSFO fuel quality issues, including possible effects on black carbon emissions.
Guidance on best practice for fuel oil suppliers has also been issued. The Guidance is intended to assist fuel oil purchasers and users in assuring the quality of fuel oil delivered to and used on board ships, with respect to both compliance with the MARPOL requirements and the safe and efficient operation of the ship. The guidance pertains to aspects of the fuel oil purchase up to the loading of the purchased fuel oil on board.
Regulations in the International Convention for the Safety of Life at Sea (SOLAS) cover issues such as flashpoint (SOLAS regulation II- 2/4.2.1).
An International Standardization Organization (ISO) standard (ISO 8217) specifies the requirements for fuels for use in marine diesel engines and boilers.
ISO has issued a further standard: ISO/PAS 23263:2019 Petroleum products – Fuels (class F) – Considerations for fuel suppliers and users regarding marine fuel quality in view of the implementation of maximum 0.50 % sulphur in 2020. It addresses quality considerations that apply to marine fuels in view of the implementation of the sulphur 2020 limit and the range of marine fuels that will be placed on the market in response. It defines general requirements that apply to all 0.50% sulphur fuels and confirms the applicability of ISO 8217 for those fuels. It gives technical considerations which might apply to particular fuels for the following characteristics: kinematic viscosity; cold flow properties; stability; ignition characteristics; and catalyst fines. Additionally, it provides considerations on the compatibility between fuels and gives additional information on ISO 8217.
7. What did IMO do to help shipowners comply with the 0.50% sulphur limit?
To assist ship operators and owners to plan ahead for the 0.50% sulphur 2020 limit, the MEPC approved various guidance and guidelines.
The 2019 Guidelines on consistent implementation of 0.50% sulphur limit under MARPOL Annex VI adopted by resolution MEPC.320(74) are available here.
These comprehensive guidelines include a template for a “Fuel Oil Non-Availability Report (FONAR)” set out in Appendix 1 and a “Technical review of identified possible potential safety implications associated with the use of 2020 compliant fuels” set out in appendix 2.
Guidance on ship implementation planning (issued November 2018) can be downloaded here.
The ship implementation planning guidance includes sections on: risk assessment and mitigation plan (impact of new fuels); fuel oil system modifications and tank cleaning (if needed); fuel oil capacity and segregation capability; procurement of compliant fuel; fuel oil changeover plan (conventional residual fuel oils to 0.50% sulphur compliant fuel oil); and documentation and reporting.
Guidance on best practice for fuel oil suppliers was also issued. The Guidance is intended to assist fuel oil purchasers and users in assuring the quality of fuel oil delivered to and used on board ships, with respect to both compliance with the MARPOL requirements and the safe and efficient operation of the ship. The guidance pertains to aspects of the fuel oil purchase up to the loading of the purchased fuel oil on board.
A full list of guidance and guidelines can be found on the infographic.
8. What is the “carriage ban” and how does it work?
The carriage ban refers to the MARPOL amendment adopted in 2018 to prohibit the carriage of non-compliant fuel oil for combustion purposes for propulsion or operation on board a ship – unless the ship has an exhaust gas cleaning system (“scrubber”) fitted.
The amendment is intended as an additional measure to support consistent implementation and compliance and provides a means for effective enforcement by States, particularly port State control.
The specific provision requires that fuel oil used on board ships shall not exceed 0.50% sulphur limit. The amended provision to prohibit the carriage of non-compliant fuel oil reads as follows: “The sulphur content of fuel oil used or carried for use on board a ship shall not exceed 0.50% m/m.”
As a result, carriage of fuel oil for use on board ships is now prohibited if the sulphur content exceeds 0.50%.
Regulation 2.9 of MARPOL Annex VI provides the definition for ‘fuel oil’ – “Fuel oil means any fuel delivered to and intended for combustion purposes for propulsion or operation on board a ship, including gas, distillate and residual fuels.”
The provision does not apply to fuel oil being carried as cargo.
9. Do small ships have to comply with the sulphur limit?
Yes, the MARPOL regulations apply to all ships. Only larger ships of 400 gross tonnage and above engaged in voyages to ports or offshore terminals under the jurisdiction of other Parties have to obtain an International Air Pollution Prevention Certificate, issued by the ship’s flag State. But all sizes of ships must use fuel oil that meets the 0.50% limit since 1 January 2020.
Some smaller ships were already using fuel oil that meets the limit, such as a marine distillate suitable for their engines.
This article is shared by courtesy of IMO. Read the rest of the frequently asked questions here.
