In April 1996 the Swedish Ports' and Stevedores' Association (SPSA), the Swedish National Maritime Administration and the Swedish Shipowners' Association reached a principle agreement on taking strong measures to reduce air pollution caused by shipping in the form of primarily nitrogen oxide and sulphur emissions. The goal set up by the parties is for these emissions to decrease by 75 % by the start of the 21st century.
The most efficient way of dramatically reducing the emission of nitrogen oxide (NOx) is to install catalytic purification of exhaust, while an equivalent reduction in sulphur emissions (SOx) is possible provided fuel with a sulphur content not exceeding 0,5 % is used. It is primarily these two measures that are dealt with in the tripartite agreement.
For the agreement in its entirety