Classification of the Barcelona Air Quality Condition (EQAB)

To facilitate the understanding of the level of Barcelona air quality in real time a five level classification has been established. These levels, represented with a colour code, range from good to very bad quality. Level scaling is based in Nitrogen Dioxide (NO2) and Particulate Matter (PM10) concentrations in the atmosphere.

The classification is based on the reference thresholds of the World Health Organization (WHO) and on the various phases established in the City Council Protocol for high pollution episodes.

EQAB NO2 Maximum hourly (µg/m3) PM10 Average per day (µg/m3)
Good 0-40 0-20
Moderate 40-140 20-40
Regular 140-160 40-50
Bad 160-200 50-80
Very bad more than 200 more than 80

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