# The Air Quality Limit Values (Scotland) Regulations 2001, Paragraph 2.1: Limit values for nitrogen dioxide and oxides of nitrogen


Averaging Period
Limit value
Margin of tolerance
Date by which limit value is to be met
1.Hourly limit value for the protection of human health
1 hour
200μg/m3 NO2 not to be exceeded more than 18 times a calendar year
290μg/m3 on 19th July 2001, reducing on 1st January of each following year by 10μg/m3 to reach 200μg/m3 by 1st January 2010
1st January 2010
2.Annual limit value for the protection of human health
Calendar year
40μg/m3 NO2
58μg/m3 on 19th July 2001 reducing on 1st January of each following year by 2μg/m3 to reach 40μg/m3 by 1st January 2010
1st January 2010
3.Annual limit value for the protection of vegetation
Calendar year
30μg/m3 NOx
None
19th July 2001

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Source: https://www.legislation.gov.uk/ssi/2001/224/schedule/1/part/II/paragraph/2n1 (the official version)
Page: https://openlegislation.uk/air-quality-limit-values-scotland-regulations-2001/schedule-1/part-II/paragraph-2n1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.