Life at sea is not easy. Lot of rules and precautions have to be taken for safe voyage as well as the seafarers. Lot of accidents have taken place in the past and if one ship meets with an accident, lot of lives and money is lost. Therefore, IMO (Indian Maritime Organisation) has come up with many sets of rules that are to be followed by people onboard. SOLAS regulates the shipping industry to follow safety at sea. MARPOL on the other hand that safeguards the marine industry against pollution at sea.

Air Pollution from Ships


MARPOL, the International Convention for the Prevention of Pollution from Ships, came into force in 1973 and then was revised in 1978. It has stated the points to make sure that the environment at the seas remains preserved by elimination of harmful substances which are discharged from the ship. It consists of six annexures stating different points. As of January 2018, 166 countries have signed for this.

The ships that have flagged under this are signatories to MARPOL and have to obey to all rules and requirements, no matter where they sail and crew they have.

MARPOL is divided into annexes according to the categories of pollutants and each have to obey different set of rules mentioned in their part.

Annex VI:- Prevention of Air Pollution from Ships

w.e.f- 19 may, 2005

Since, ships float on water, it’s seen that they don’t have any direct cause of air pollution. But there are lot of accidents and incidents that impose a lot of damage to air. One such accident is oil spills that

not only causes a lot of water pollution but also produces a lot of harmful gases into the atmosphere which can be very toxic for the environment. These gases thereby cause acid rains that has a lot of negative impact on nature.

MARPOL Annex 6 was adopted in 1997. It gives points to reduce main air pollutants that are exhausted by the ships and they’re sulphur oxides, ozone depleting substances (ODS) and nitrous oxides. It also gives instructions about shipboard incineration and volatile organic compounds (VOC) emissions from the tankers.

So, basically MARPOL Annex VI addresses the following points:-

*The impact that the air pollution has on human health and environment from shipping activities.

*The impact due to emissions from shipping activities on weather, change of climate and the process of depletion of ozone layer. Later, Annex 6 of MARPOL was decided to be revised. So, on 19th May 2005, Marine Environment Protection Committee (MEPC) revised MARPOL Annex 6 and it came into force on 1st July 2010.

Revised Annex VI

The most important amendments that were done in Annex 6 are control of progressive global emissions of sulphur oxides, nitrogen oxides and particulate matter. It also brought introduction of emission control areas (ECAs). Its purpose was to reduce emissions of air pollutants in designated sea areas.

Because of the revised annexure, it was predicted that the global sulphur limit would be reduced from 3.50% to 0.50% effective from 1st January 2020.

Reductions in nitrogen oxides emissions limits from marine diesel engines on ships were also included with a “Tier 2” emission limit; also, a “Tier 3” emission limit for engines was also imposed on ships constructed on or after 1st January 2016. Marine engines installed on ship on or after 1st January 1990 but prior to 1st January 2000 are required to comply with “Tier 1“ limits.

Nitrogen Oxide(NOx) controls the marine diesel engines that have a power output of 130 KW or above, on vessels built on or after 1st January 2000.

Later more amendments were made to these three tiers to make them even more successful. Revisions to regulations for the substances that deplete the ozone layer, volatile organic compounds, shipboard incineration, reception facilities and the quality of the fuel used and it also made regulations on the availability of fuel oil.

These revisions in MARPOL Annexure 6 has proven to be very beneficial to the shipping industry as well as the environment. This has also proven to reduce the effects on human and marine health, especially to the people onboard and those in port cities.

IMO 2020 Sulfur Cap

The MARPOL on and after 1st January 2020 permitted limit for sulphur content in ships’ bunker fuel oil to be reduced from 3.5% by mass (m/m) to 0.50% m/m for ships operating outside designated emission control areas. The ECA limit of 0.10% will still apply.

The International Group Clubs recognize that the 2020 Global Sulphur Cap presents important challenges to the mariners and are closely monitoring discussions at the IMO. There are penalties for non-compliance of these rules and they include detentions, fines, etc.


*The MARPOL permitted limit for the content of sulphur in ships’ bunker from 1st January 2020 will be reduced from 3.5% to 0.50% m/m. This is for the ships operating outside designated emission control areas.

*From 1st March 2020, the carriage of non-compliant fuel had prohibition to it.

*The penalties that are charged because of non-compliance of these rules are fines, detentions and maybe PSC banning orders.

*The discretion of the Club’s Board of Directors makes available the cover for other fines.

Authored By:- Cdt. Rounak Raj, TMI

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