You are here: Home / Documentation / FAQ / Which concentrations may not be exceeded?

Which concentrations may not be exceeded?

The 2008 European directive on air quality sets limit values for some pollutants. They are science-based concentration levels that must not be exceeded in order to reduce harmful effects on human health and/or the environment as a whole.

The limit values are maximum concentrations expressed in µg/m³ for different time periods: hourly, daily or annual average concentration. There are levels for sulphur dioxide, nitrogen dioxide, PM₁₀, PM₂.₅, lead, benzene and carbon monoxide.

Pollutant

 Averaging period

Limit value

Date by which limit value is to be met

PM₁₀

Annual average

40 µg/m³

Since 1 January 2005

 

Daily average

50 µg/m³

Since 1 January 2005

PM₂.₅

Annual average

25 µg/m³

Since 1 January 2015

Benzeen

Annual average

5 µg/m³

Since 1 January 2010

CO

Maximum daily eight hour mean

10 µg/m³

Since 1 January 2005

Lood

Annual average

0,5 µg/m³

Since 1 January 2005

NO₂

Annual average

40 µg/m³

Since 1 January 2010

 

Hourly average

200 µg/m³

Since 1 January 2010

SO₂

Daily average

125 µg/m³

Since 1 January 2005

Hourly average 350 µg/m³

Since 1 January 2005

In addition to these limit values, which are mandatory to attain, the directive also describes target values, information thresholds and alert thresholds for various pollutants. Target values are concentrations to be attained where possible, while information and alert thresholds are concentration levels at which Belgium is obliged to inform the public.

Every year, we test the entire Belgian territory against these limit values in our annual air quality report.

Navigation