Pollutant

Averaging interval

Limit value
LV

Margin
of tolerance
MT

Assessment threshold

Date
for achieving LV

Upper
UAT

Lower
LAT

SO₂

calendar year
and winter season
(1. 10.-31. 3.)

20 μg.m^-3

without margin
of tolerance

12 μg.m^-3

8 μg.m^-3

on coming the 
Regulation into force

NO_x

calendar year

30 μg.m^-3

without margin
of tolerance

24 μg.m^-3

19.5 μg.m^-3

on coming the 
Regulation into force

O₃

AOT40, calculated from 1-h
values in the period May-July,
average for 5 years

18 000 μg.m^-3.h

without margin
of tolerance

6 000 μg.m^-3.h

-

1. 1. 2010