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Regulations for the Prevention of Air Pollution from Ships to Be Further Strengthened

Date. 2021-04-28
Hit. 244

- Permissible emission limits for nitrogen oxides (NOx) and sulfur oxides (SOx) to be strengthened and range of applicability expanded -


The Ministry of Oceans and Fisheries (MOF; Minister Moon, Seong-hyeok) stated that according to the revised “Regulations for the Prevention of Pollution from Ships,” the permissible nitrogen oxide (NOx) emission limit for domestic ships will be strengthened starting May 19th (Wednesday).


Up to now, “Tier 1*” from the table below has been applied to domestic ships constructed in or after 2006 while “Tier 2**” has been applied to ships constructed in or after 2013. Tier 2 requires a 20% reduction in the emission of nitrogen oxides compared to Tier 1. However, when a ship’s engine was replaced with a diesel engine constructed before 2013, Tier 1 has been exceptionally applied.


<Permissible Nitrogen Oxide Emission Limits for Ships (Enforcement Rule of the Clean Air Conservation Act, Attached Table 35)>

Engine power Rated engine speed
(n=crankshaft revolutions per minute)
Nitrogen oxide emission standards (g/kWh)
Tier 1 Tier 2
Excess of 130kW n=less than 130rpm 17 or less 14.4 or less
n=130rpm - 2,000rpm 45.0×n(-0.2) or less 44.0×n(-0.23) or less
n=2,000rpm or more 9.8 or less 7.7 or less

* Emission tiers: emission restrictions applicable to diesel engines to keep the nitrogen oxide emissions (g) per kWh at or below the standards. The emission amount depends on the engine’s power and speed

** For a diesel engine running at 1,000 rpm, application of Tier 2 results in an approximate 20.5% reduction in nitrogen oxide emissions compared to Tier 1.


Starting on May 19th, however, Tier 2 will be applied to all replacement engines regardless of their years of manufacture, strengthening nitrogen oxide emissions restrictions. In the case of ships on international navigation, Tier 2 is already being applied to ships constructed in or after 2011 and Tier 1 to ships constructed in or after 2000, in both cases without exception.


Sulfur oxides (SOx) are another type of air pollutant produced by ships together with nitrogen oxides. Therefore, the standards for sulfur content in ship fuel have been considerably strengthened from 3.5% to 0.5%, from January 2020 for ships on international navigation and from the inspection date of marine pollution prevention equipment this year for domestic ships with such equipment. These standards will apply to all ships starting January 1st next year for the continued reduction of sulfur oxides emissions.


Besides, strengthened Sulfur Content Standards for Fuel Oil are currently only applicable to ships anchoring or coming alongside the sulfur oxides emission control areas designated in five principal harbors (sulfur content 0.1% or below). However, starting from January 1st next year, reinforced standards will be applied to all ships from the entry and exit of the emission control area.

* Emission control areas (5 ports): Busan Harbor, Incheon Harbor, Yeosu/Gwangyang Harbor, Pyeongtaek/Dangjin Harbor


Choi Jong-wook, Director of the Maritime Industry and Technology Division of MOF, stated, “The expanded applicability and revisions of the nitrogen oxides and sulfur oxides emission regulations concerning domestic ships and principal ports are expected to significantly reduce pollutant emissions such as fine dust, contributing to an improvement of air quality in port areas.” He continued, “The Ministry of Oceans and Fisheries will do its best for the distribution and promotion of environmentally-friendly ships such as by obligating the central government or municipal governments to construct environmentally-friendly ships and providing subsidies of up to 20% of the ship price to private shipping companies constructing such ships.”