{
  "url": "https://openlegislation.uk/air-quality-limit-values-regulations-northern-ireland-2002/schedule-2/part-I",
  "json_url": "https://openlegislation.uk/air-quality-limit-values-regulations-northern-ireland-2002/schedule-2/part-I.json",
  "legislation": "nisr/2002/94",
  "legislation_title": "The Air Quality Limit Values Regulations (Northern Ireland) 2002",
  "legislation_url": "https://openlegislation.uk/air-quality-limit-values-regulations-northern-ireland-2002",
  "path": "schedule/2/part/I",
  "kind": "part",
  "number": "I",
  "heading": "UPPER AND LOWER ASSESSMENT THRESHOLDS",
  "text": "The following upper and lower assessment thresholds will apply:\n(a) SULPHUR DIOXIDE\nHealth protection\nEcosystem protection\nUpper assessment threshold\n60% of 24-hour limit value (75 μg/m3) not to be exceeded more than 3 times in any calendar year\n60% of winter limit value (12 μg/m3)\nLower assessment threshold\n40% of 24-hour limit value (50 μg/m3) not to be exceeded more than 3 times in any calendar year\n40% of winter limit value (8 μg/m3)\n(b) NITROGEN DIOXIDE AND OXIDES OF NITROGEN\nHourly limit value for the protection of human health (NO2)\nAnnual limit value for the protection of human health (NO2)\nAnnual limit value for the protection of vegetation (NOx)\nUpper assessment threshold\n70% of limit value (140 μg/m3) not to be exceeded more than 18 times in any calendar year\n80% of limit value (32 μg/m3)\n80% of limit value (24 μg/m3)\nLower assessment threshold\n50% of limit value (100 μg/m3) not to be exceeded more than 18 times in any calendar year\n65% of limit value (26 μg/m3)\n65% of limit value (19.5 μg/m3)\n(c) PARTICULATE MATTER\n24-hour average\nAnnual average\nUpper assessment threshold\n60% of limit value (30 μg/m3) not to be exceeded more than 7 times in any calendar year\n70% of limit value (14 μg/m3)\nLower assessment threshold\n40% of limit value (20 μg/m3) not to be exceeded more than 7 times in any calendar year\n50% of limit value (10 μg/m3)\nAveraging Period\nLimit Value\nMargin of tolerance\nDate by which limit value is to be met\n1 24-hour limit value for the protection of human health\n24 hours\n50mg/m3 PM10 not to be exceeded more than 7 times a calendar year\nTo be derived from data and to be equivalent to Stage 1 limit value.\n1st January 2010\n2 Annual limit value for the protection of human health\nCalendar year\n20 mg/m3 PM10\n50% on 1st January 2005 reducing every 12 months thereafter by equal annual percentages to reach 0% by 1st January 2010\n1st January 2010\n(d) LEAD\nAnnual average\nUpper assessment threshold\n70% of limit value (0.35 μg/m3)\nLower assessment threshold\n50% of limit value (0.25 μg/m3)",
  "extent": "N.I.",
  "status": null,
  "version": "current",
  "annotations": [
    {
      "type": "I",
      "label": "I1",
      "text": "Sch. 2 Pt. I in operation at 1.5.2002, see reg. 1"
    },
    {
      "type": "footnote",
      "label": "f1",
      "text": "The upper and lower assessment thresholds for PM10 are based on the following indicative limit values for 1 January 2010, which will be reviewed in the light of further information on health and environmental effects, technical feasibility and experience in the application of the existing “Stage 1” limit values"
    }
  ],
  "outstanding_effects": [
    {
      "type": "added",
      "affecting": "nisr/2002/357",
      "affecting_title": "The Air Quality Limit Values (Amendment) Regulations (Northern Ireland) 2002"
    }
  ],
  "provenance": {
    "source": "legislation.gov.uk",
    "source_url": "https://www.legislation.gov.uk/nisr/2002/94/schedule/2/part/I",
    "retrieved_at": "2026-10-29T02:08:23.952723+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."
}