The Air Quality Directive 2008/50/EG having been adopted by the European Parliament and the European Union Council and having come into effect on 11th June, 2008, serves as a basis for the avoidance of health risks caused by nitrogen dioxide and fine dust. With date from 11th June, 2010, the directive replaced the former Air Quality Framework Directive (Directive 96/62/EG of the Council dated 27th September, 1996, about the assessment and supervision of air quality dated 27th September, 1996).
The required transposition into national law has been realised in Germany by means of an adaptation of the application of the Federal Immission Control Act and by adoption of a new legislative decree (39th BimSchV Federal Emission Control Act). According to these directives, two limit values have been applied for NO2 in the ambient air since 2010:

• The annual average must not exceed 40 µg/m³
• The maximum values are allowed to be exceeded not more often than 18 times per year above 200 µg/m³

As far as cities knew already in 2008 that these limited values could not be observed for a longer period, they could address themselves to the EU commission in order to apply for an extension of time of up to five years after entry into force which meant until the year 2015 maximum.
However, an extension of time could only be guaranteed if the community could prove demonstrably and logically with the aid of a clean air plan how the required limits could be observed in the future.
But more than half of the applications submitted to the EU commission have been rejected so far because the responsible authorities could not prove how and by which suitable means they will guarantee the respect of the required limit values.
But also the other half of the cities/communities having obtained an extension of time will be confronted with the problem clean air plan, their 5 years transitional period expired in December 2015
If from the beginning of 2016 a member state should be unable to prove the observance of limit values, a confrontation with an infringement procedure allied with a fine will take place.