# The Air Quality Standards Regulations 2010, Schedule 5: Information and alert thresholds


Alert thresholds for Sulphur dioxide and Nitrogen dioxide
1 To be measured over three consecutive hours at locations representative of air quality over at least 100 km 2 or an entire zone, whichever is smaller.
Pollutant
Alert threshold 1
Sulphur dioxide
500 µg/m3
Nitrogen dioxide
400 µg/m3
Information and alert thresholds for ozone
Purpose
Averaging period
threshold
Information
1 hour
180 µg/m3
Alert
1 hour
240 µg/m3

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Source: https://www.legislation.gov.uk/uksi/2010/1001/schedule/5 (the official version)
Page: https://openlegislation.uk/air-quality-standards-regulations-2010/schedule-5
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.