# The Air Quality (Wales) Regulations 2000, Part I

Extent: E+W

TABLE
AIR QUALITY OBJECTIVES
Substance/ Air Quality Objective levels
Date by which objective to be achieved
Benzene: 16.25 micrograms per cubic metre or less, when expressed as a running annual mean
31 December 2003
Benzene: 5 micrograms per cubic metre or less, when expressed as an annual mean
31 December 2010
1, 3 -Butadiene: 2.25 micrograms per cubic metre or less, when expressed as a running annual mean
31 December 2003
Carbon monoxide: 10 milligrams per cubic metre or less, when expressed as a maximum daily running 8 hour mean
31 December 2003
Nitrogen dioxide: 200 micrograms per cubic metre or less, when expressed as an hourly mean, not to be exceeded more than 18 times a year
31 December 2005
Nitrogen dioxide: 40 micrograms per cubic metre or less, when expressed as an annual mean
31 December 2005
Lead: 0.5 micrograms per cubic metre or less, when expressed as an annual mean
31 December 2004
Lead: 0.25 micrograms per cubic metre or less, when expressed as an annual mean
31 December 2008
PM10: 50 micrograms per cubic metre or less, when expressed as a 24 hour mean, not to be exceeded more than 35 times a year
31 December 2004
PM10 40 micrograms per cubic metre or less, when expressed as an annual mean
31 December 2004
Sulphur dioxide: 125 micrograms per cubic metre or less, when expressed as a 24 hour mean, not to be exceeded more than 3 times a year
31 December 2004
Sulphur dioxide: 350 micrograms per cubic metre or less, when expressed as an hourly mean, not to be exceeded more than 24 times a year
31 December 2004
Sulphur dioxide: 266 micrograms per cubic metre or less, when expressed as a 15 minute mean, not to be exceeded more than 35 times a year
31 December 2005

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Source: https://www.legislation.gov.uk/wsi/2000/1940/schedule/part/I (the official version)
Page: https://openlegislation.uk/air-quality-wales-regulations-2000/schedule/part-I
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.