Local Air Quality (LAQ)
One of ICAO's environmental goals is to limit or reduce the impact of aviation emissions on local air quality (LAQ). Starting during the late 1970s, ICAO has been developing measures to address emissions from aircraft engines in the vicinity of the airport and from relevant airport sources. Volume II of Annex 16 to the Convention on International Civil Aviation contains Standards for aircraft engine emissions and is accompanied by related guidance material and technical documentation.
Following the successful adoption of the CAEP/10 nvPM Standard based on visibility criterion, CAEP/11 agreed on nvPM mass and number Standard, which was adopted by the ICAO Council in March of 2020 and is applicable from January 2021 onwards. For the new triennium (2025-2028), CAEP will develop new NOx LTO stringency options based on the existing NOx metrics and building upon already reached progress on this topic.
ICAO provisions on LAQ also address liquid fuel venting, non-volatile Particulate Matter (nvPM) impacts from mass and particles number perspectives, and the main gaseous exhaust emissions from jet engines, namely: hydrocarbons (HC), oxides of nitrogen (NOx), carbon monoxide (CO).
More details on the ICAO initiatives on LAQ are provided in the following pages: