In order to protect human health and the environment, the Council of the European Union drew up a directive with air quality standards in April 1999. The Hungarian government transposed the European Air Quality Directive into national law by 11 June 2011. Before this the Commission sent a reasoned opinion, because the legislation was not adopted in Hungary by 11 June 2010. The directive establishes limit values for pollutant concentration in order to maintain the air quality. Accordingly, the limit value for particulate matter was set at 50 micrograms per cubic meter of air, which may be exceeded on a maximum of 35 days a year. The average annual value for nitrogen dioxide was set at 40µg/m3. The county government offices are responsible for preparing and controlling air quality plans in the regions where the pollution exceeds the limit values. Air quality plans were prepared accordingly for several zones and their agglomeration in 2005. Then, in 2008 the plans were amended and have been reviewed several times since then, because of the continuous breaches of limit values. The plans should contain a list and the description of measures, a timetable for implementation of some measures and an estimation of the improvement of the air quality. Unfortunately the majority of the air quality plans fail to provide with concrete measures and strict, short term deadlines. Moreover, due to the lack of political will, not all measures have been implemented according to the timetable. In 2018, Clean Air Action Group (CAAG), a Hungarian NGO launched a legal procedure with the support of ClientEarth in order to have the air quality plan of Budapest and its agglomeration reviewed. The NGO also decided to start a similar case in the countryside and to use all appeal and remedy possibilities available in both cases to reach more effective plans.
The general administrative law of Hungary allows clients to participate in an administrative procedure. According to the environmental law, NGOs are entitled to take part in environmental administrative procedures as clients and therefore take part in the decision-making as well as access to justice. In addition, if a certain project has an impact area, those who live there can also act as clients. Additionally the Hungarian Environmental Law entitles the NGOs operating in the field of environmental protection to litigate in order to prohibit activities causing environmental pollution or harm. Residents concerned may appeal to the municipal notary or to the court against anybody who violates their property e.g. by polluting their environment (property protection). Individuals concerned can also go to the civil court for compensation if they have suffered material or immaterial damages. In the recent years CAAG have used or supported the whole variety of legal actions concerning air pollution trying to put pressure on the decision-makers and the authorities to ensure better air quality in Hungary.