ANNEX XII
INFORMATION AND ALERT THRESHOLDS
A. Alert thresholds for pollutants other than ozone
To be measured over three consecutive hours at locations representative of air quality over at least 100 km2 or an entire zone or agglomeration, whichever is the smaller.
Pollutant | Alert threshold
Sulphur dioxide | 500 μg/m3
Nitrogen dioxide | 400 μg/m3
B. Information and alert thresholds for ozone
Purpose | Averaging period | Threshold
Information | 1 hour | 180 μg/m3
Alert | 1 hour (1) | 240 μg/m3
(1)(^{1}) For the implementation of Article 24, the exceedance of the threshold is to be measured or predicted for three consecutive hours.