The primary focus for introduction of emissions charges was: Reduction of specific aviation emissions by supporting and forcing the use of best available technology.

Aircraft engines are divided into five emission classes, according to their charging emission factor. The charging emission factor of a particular engine is the sum of NOx- and HC-emissions in the landing and take-off cycle (LTO), divided by the maximum thrust of the engine.

Depending on the emission class of the engine, the emissions charge will be a percentage between 0 and 40% of the landing charge. The revenue has to be strictly used for measures to reduce negative impact on local air quality by the airport.

Classification of jet, turboprop, piston and helicopter engines:

There has been a need for international harmonization of existing emissions charges models. Switzerland has contributed to the development of a new European model, which is recommended by the European Civil Aviation Conference (ECAC). The new model (ECAC 27/4) strongly follows the polluter pays principle. The basis for the so called emission value of a certain engine is the absolute amount of NOx emissions in the landing and take-off cycle. Sweden was the first country to change to the new model. In the UK, Heathrow airport has introduced a similar model and Switzerland plans to change to the ECAC model, too.