Titre European standards

In terms of air quality, three levels of overlapping standards can be distinguished (European, national and local). All of these regulations has main purposes:

  • Assessment of the pollution exposure of the population and vegetation.
  • The evaluation of the actions undertaken by the various authorities in order to limit this pollution.
  • To inform about air quality.

The Community strategy for monitoring air quality is based on the European Directive (2008/50/EC) of 14 April 2008 ( pdf - 231 ko) and Directive No. 2004/107/EC of 15 December 2004 ( pdf - 79 ko). These guidelines establish measures to:

  • Define and fix objectives for ambient air quality in order to avoid, prevent or reduce harmful effects on human health and the environment as a whole.
  • Assess the ambient air quality in Member States on the basis of common methods and criteria.
  • Obtain information on the quality of ambient air in order to contribute against air pollution and nuisance and to monitor long-term trends and improvements resulting from national and Community measures.
  • Ensure that information on the quality of ambient air is available to the public.
  • Preserve the quality of ambient air, where it is good and improve it in other cases.
Polluants Limit value Alert threshold Critical level
Nitrogen dioxide
Annual mean: 40 µg/m³.

Hourly mean:
200 µg/m³ not to be exceeded more than 18 per year.
400 µg/m³ exceeded on 3 consecutive hours.

Nitrogen oxides

Annual mean (NO2 equivalent):
30 µg/m³ (for the vegetation protection).
Sulphur dioxide
Hourly mean (for the protection of human Health): 125 µg/m³ not to be exceeded more than 3 per year.

Daily mean (for the protection of human health): 350 µg/m³ not to be exceeded more than 24 per year.
Hourly mean 500 µg/m³ exceeded on 3 consecutive hours.

Annual & winter mean - (for the vegetation protection ) : 20 µg/m³.

Annual mean: 0,5 µg/m³.

Particles with a diameter of 10 micrometers or less
Annual mean: 40 µg/m³.

Daily mean: 50  µg/m³ not to be exceeded more than 35 per year.
Carbon monoxide
Maximum daily on a 8-hour mean: 10 000 µg/m³.
Annual mean: 5 µg/m³.
Polluant Target value Long-term objectives

Recommendation and information threshold

Alert threshold
Protection of human Health:
on a hourly running 8 hours average: 120 µg/m³, not to be exceeded on more than 25days per calendar year averaged over 3years.

Protection of AOT 40* from May to July 8am to 8pm: 18 000 µg/m³.h (average over 5years).
Protection of human Health:
on a maximum daily eight-hour mean: 120 µg/m³ per civil year.

Protection of Vegetation, AOT 40* from May to July 8am to 8pm: 6 000 µg/m³.h.
Hourly mean: 180 µg/m³. Information : 240 µg/m³ hourly mean.

Mandatory actions: 240 µg/m³ during 3 consecutive hours.
*AOT40 (expressed in (μg/m3) ∙ hours) means the sum of the difference between hourly concentrations greater than 80 μg/m3 (= 40 parts per billion) and 80 μg/m3 over a given period using only the one-hour values measured between 8.00 and 20.00 Central European Time (CET) each day.
Polluant Limit value Target value Exposure reduction target relative to the AEI**2011 Exposure concentration obligation
Particles with a diameter of 2.5 micrometers or less

Protection of human Health:
Annual mean:
Phase 1 : 27,9 µg/m³ for 2011, decreasing every year by equal annual percentage to reach 25 µg/m³ by 2015.
Phase 2 : 20 µg/m³ in 2020*.

Protection of human Health: Annual mean : (which should be met by 2010):  25 µg/m³.

Initial Concentration: Reduction target in percent:
<= à 8,5 µg/m³ 0%
>=8,5 and <13 µg/m³ 10%
>=13 and <18 µg/m³ 15%
>=18 and <22 µg/m³ 20%
>= à 22 µg/m³ All appropriate measures to archive
18 µg/m³
20 µg/m³ by AEI** 2015.
* to be reviewed by the European Commission in 2013 in the light of information on the health and environmental impact, technical feasibility and experience gained in the target value in Member States.
** AEI : The Average Exposure Indicator (AEI), is a 3 calendar year running annual mean concentration average. (ex : AEI 2011 is the annual concentration average for the year 2009, 2010, 2011).
Limit value (Annual mean) :
decreasing every year

2008: 30 µg/m³
2009: 29,3 µg/m³
2010: 28,6 µg/m³
2011: 27,9 µg/m³
2012: 27,1 µg/m³
2013: 26,4 µg/m³
2014: 25,7 µg/m³
2015: 25 µg/m³
Polluant Target value*
which should be met by the 31st of December 2012

6 ng/m³


5 ng/m³


20 ng/m³

(used as a tracer of the carcinogenic risk of polycyclic aromatic hydrocarbons - PAHs)

1 ng/m³

* Averaged over the calendar year of the total content in the PM10 fraction