# The Air Quality Standards (Wales) Regulations 2010, Paragraph

Extent: E+W

Alert thresholds for sulphur dioxide and nitrogen dioxide
Pollutant
Alert threshold
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/wsi/2010/1433/schedule/4/paragraph/wrapper4n1 (the official version)
Page: https://openlegislation.uk/air-quality-standards-wales-regulations-2010/schedule-4/paragraph-wrapper4n1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.