{
  "url": "https://openlegislation.uk/air-quality-standards-regulations-2010/regulation-2",
  "json_url": "https://openlegislation.uk/air-quality-standards-regulations-2010/regulation-2.json",
  "legislation": "uksi/2010/1001",
  "legislation_title": "The Air Quality Standards Regulations 2010",
  "legislation_url": "https://openlegislation.uk/air-quality-standards-regulations-2010",
  "path": "regulation/2",
  "kind": "regulation",
  "number": "2",
  "heading": "Definitions",
  "text": "In these Regulations—\n“ambient air” means outdoor air in the troposphere, excluding workplaces where members of the public do not have regular access;\n“AOT 40” (expressed in (μg/m3)∙ hours) means the sum of the difference between hourly concentrations greater than 80 μg/m3 (=40 parts per billion) and 80 μg/m3 over a given period using only the one-hour values measured between 08.00 hours and 20.00 hours Central European Time (CET) each day;\n“arsenic”, “cadmium”, “nickel” and “benzo(a)pyrene” mean the total content of those elements and compounds within the PM10 present in ambient air;\n“Directive 2008/50/EC” means Directive 2008/50/EC of the European Parliament and of the Council on ambient air quality and cleaner air for Europe;\n“Directive 2004/107/EC” means Directive 2004/107/EC of the European Parliament and of the Council relating to arsenic, cadmium, mercury, nickel and polycyclic aromatic hydrocarbons in ambient air;\n“fixed measurements” means measurements taken at fixed locations, either continuously or by sampling from time to time, to determine levels of pollutants in accordance with the relevant data quality objectives;\n“indicative measurement” means measurements which meet data quality objectives that are less strict than those required for fixed measurements;\n“margin of tolerance” means the percentage of the limit value by which that value may be exceeded in a given year;\n“oxides of nitrogen” means the sum of the volume mixing ratio (ppbv) of nitrogen monoxide (nitric oxide) and nitrogen dioxide expressed in units of mass concentration of nitrogen dioxide (μg/m3);\n“ozone precursor substances” means substances which contribute to the formation of ground level ozone;\n“PM10” means particulate matter which passes through a size-selective inlet as defined in the reference method for the sampling and measurement of PM10, EN 12341, with a 50% efficiency cut-off at 10 μm aerodynamic diameter;\n“PM2.5” means particulate matter which passes through a size-selective inlet as defined in the reference method for the sampling and measurement of PM2.5, EN 14907, with a 50% efficiency cut-off at 2.5μm aerodynamic diameter;\n“particulate matter” means PM2.5 and PM10;\n“pollutant” means any of the following—\n(a)sulphur dioxide,\n(b)nitrogen dioxide,\n(c)oxides of nitrogen,\n(d)particulate matter,\n(e)lead,\n(f)benzene,\n(g)carbon monoxide,\n(h)arsenic,\n(i)cadmium,\n(j)mercury,\n(k)nickel,\n(l)benzo(a)pyrene or other polycyclic aromatic hydrocarbons,\n(m)ozone;\n“polycyclic aromatic hydrocarbons” means those organic compounds composed of at least two fused aromatic rings made entirely from carbon and hydrogen;\n“relevant administration” means—\n(a)the Welsh Ministers for Wales;\n(b)the Scottish Ministers for Scotland; and\n(c)the Department of the Environment for Northern Ireland;",
  "extent": "E+W+S+N.I.",
  "status": null,
  "version": "current",
  "annotations": [
    {
      "type": "F",
      "label": "F1",
      "text": "Words in reg. 2 substituted (31.12.2016) by The Air Quality Standards (Amendment) Regulations 2016 (S.I. 2016/1184), regs. 1(1), 2(1)"
    },
    {
      "type": "F",
      "label": "F2",
      "text": "Words in reg. 2 substituted (31.12.2016) by The Air Quality Standards (Amendment) Regulations 2016 (S.I. 2016/1184), regs. 1(1), 2(2)"
    }
  ],
  "outstanding_effects": [],
  "provenance": {
    "source": "legislation.gov.uk",
    "source_url": "https://www.legislation.gov.uk/uksi/2010/1001/regulation/2",
    "retrieved_at": "2026-10-29T02:45:20.255559+00:00"
  },
  "licence": "Open Government Licence v3.0",
  "licence_url": "https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/",
  "attribution": "Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives."
}