European Commission closes infringement procedure against Bulgaria over air quality

The European Commission has closed the infringement procedure against Bulgaria concerning air quality, after the country took measures to address exceedances of the limit values for sulfur dioxide (SO₂) set out in the Air Quality Directive (INFR (2009) 2135).

The case was opened in 2009 to ensure that Bulgaria reduced ambient air levels of sulfur dioxide — a pollutant from industrial installations that can cause respiratory problems and exacerbate cardiovascular disease.

In July 2019, the Commission referred Bulgaria to the Court of Justice of the European Union (CJEU). The Court’s ruling on 12 May 2022 confirmed that the limit values for SO₂ in the south-eastern region had been systematically exceeded for several years after Bulgaria joined the EU, and that the country had not taken adequate measures to keep the period of exceedance as short as possible.

Following the 2022 CJEU decision, Bulgarian authorities implemented measures to reduce emissions in the south-eastern zone, home to the country’s four largest thermal power plants. In January 2023, Bulgaria also amended national legislation to provide for real-time data reporting.

Additional preventive measures were introduced, including enhanced monitoring and instructions to reduce emissions during exceedances and under adverse weather conditions.

Air quality data reported by Bulgaria show compliance with the daily and hourly SO₂ limit values for three consecutive years — 2022, 2023 and 2024. This outcome, together with the measures taken to achieve it, led the Commission to conclude that Bulgaria has appropriately addressed the concerns identified by the CJEU in May 2022.