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 (NO2) |
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 (NOx) |
Annual mean (NO2 equivalent): 30 µg/m³ (for the vegetation protection). |
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Sulphur dioxide (SO2) |
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. |
Lead (Pb) |
Annual mean: 0,5 µg/m³. |
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Particles with a diameter of 10 micrometers or less (PM10) |
Annual mean: 40 µg/m³. Daily mean: 50 µg/m³ not to be exceeded more than 35 per year. |
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Carbon monoxide (CO) |
Maximum daily on a 8-hour mean: 10 000 µg/m³. |
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Benzene (C6H6) |
Annual mean: 5 µg/m³. |

Polluant | Target value | Long-term objectives | Recommendation and information threshold |
Alert threshold |
---|---|---|---|---|
Ozone (O3) |
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 (PM2,5) |
Protection of human Health: |
Protection of human Health: Annual mean : (which should be met by 2010): 25 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). |

Polluant | Target value* which should be met by the 31st of December 2012 |
---|---|
Arsenic | 6 ng/m³ |
Cadmium | 5 ng/m³ |
Nickel | 20 ng/m³ |
Benzo(a)pyrène (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 |