Air quality is managed through regulation of the major sources of emissions. The regulatory process for controlling emissions from large point sources such as industrial processes and combustion sources is complex and varies from region to region. In general terms, the process takes into account national and regional targets as well as the current regional and local air quality. These are considered in the context of cost benefit analyses which considers a number of factors including the capabilities of Best Available Technologies. The process is coordinated and managed through a permitting procedure.

The global regulatory framework for controlling air pollution cascades from the World Health Organisation (WHO) Air Quality Guidelines, which offer guidance on thresholds and limits for key air pollutants globally.

WHO Air Quality Guidelines 2005

Pollutant Guideline Values
PM2.5 10 μg/m3 annual mean 25 μg/m3  24-hour mean
PM10 20 μg/m3 annual mean 50 μg/m3  24-hour mean
O3 100 μg/m3  8-hour mean
NO2 40 μg/m3 annual mean 200 μg/m3  1-hour mean
SO2 20 μg/m3 24-hour mean 500 μg/m3  10-minute mean


Regional legislation, such as the EU Ambient Air Quality Directive and the US Environmental Protection Agency (EPA) National Ambient Air Quality Standards (NAAQS) set legally binding limits for concentrations of major air pollutants that impact public health. Regional and national authorities also set technology-based standards for specific sectors. Such limits and standards are transposed into national law. It is the responsibility of national and local authorities to enforce standards and to manage the emissions from point sources. 

Details on the United States Clean Air Legislation may be found at:

Information about the EPA's Mercury and Air Toxics Standards (MATS):

Information about RICE NESHAP may be found at:

Information on EU Emissions Limits may be found at:

Information on China Air Pollution Control is available at:

Information on India Air Quality Standards is available at:

Information on Latin America Air Quality is available at:

Information about Worldwide Diesel Engine Emissions Regulations may be found at:

Information about Worldwide NOx Emissions Regulations for Marine Diesel and related engines may be found at: