National Institute of Meteorology and Hydrology

Bulgaria Academy of Sciences

National Institute of Geophysics, Geodesy and Geography

Bulgarian legislation for Ozone (O3):
Daily maximum (8-hour running average) threshold (D8T): 120 μg/m3
Permitted number of exceedings of D8T in a year: 25 (mean for 3 years)
Information threshold (hourly value): 180 μg/m3
Alert threshold (hourly value): 240 μg/m3


Funded by the
National Science Fund of Bulgaria