{
  "url": "https://openlegislation.uk/control-of-major-accident-hazards-regulations-2015/schedule-1/paragraph-4",
  "json_url": "https://openlegislation.uk/control-of-major-accident-hazards-regulations-2015/schedule-1/paragraph-4.json",
  "legislation": "uksi/2015/483",
  "legislation_title": "The Control of Major Accident Hazards Regulations 2015",
  "legislation_url": "https://openlegislation.uk/control-of-major-accident-hazards-regulations-2015",
  "path": "schedule/1/paragraph/4",
  "kind": "paragraph",
  "number": "4",
  "heading": null,
  "text": "The following rules governing the addition of dangerous substances, or categories of dangerous substances, apply where appropriate.\nIn the case of an establishment where no individual dangerous substance is present in a quantity above or equal to the relevant qualifying quantity, the following rule must be applied to determine whether these Regulations apply to the establishment.\nAn establishment is an upper tier establishment if the sum: q1/QU1 + q2/QU2 + q3/QU3 + q4/QU4 + q5/QU5 + … is greater than or equal to 1, where qx = the quantity of dangerous substance x (or category of dangerous substances) falling within Part 1 or Part 2 of this Schedule, and QUX = the relevant qualifying quantity of dangerous substance or category x from Column 3 of Part 1 or from Column 3 of Part 2 of this Schedule.\nAn establishment is a lower tier establishment if the sum: q1/QL1 + q2/QL2 + q3/QL3 + q4/QL4 + q5/QL5 + … is greater than or equal to 1, where qx = the quantity of dangerous substance x (or category of dangerous substances) falling within Part 1 or Part 2 of this Schedule, and QLX = the relevant qualifying quantity for dangerous substance or category x from Column 2 of Part 1 or from Column 2 of Part 2 of this Schedule.\nThis rule must be used to assess the health hazards, physical hazards and environmental hazards. It must therefore be applied three times—\n(a) for the addition of dangerous substances listed in Part 2 that fall within acute toxicity category 1, 2 or 3 (inhalation route) or STOT SE category 1, together with dangerous substances falling within section H, entries H1 to H3 of Part 1;\n(b) for the addition of dangerous substances listed in Part 2 that are explosives, flammable gases, flammable aerosols, oxidising gases, flammable liquids, self-reactive substances and mixtures, organic peroxides, pyrophoric liquids and solids, oxidising liquids and solids, together with dangerous substances falling within section P, entries P1 to P8 of Part 1;\n(c) for the addition of dangerous substances listed in Part 2 that fall within hazardous to the aquatic environment acute category 1, chronic category 1 or chronic category 2, together with dangerous substances falling within section E, entries E1 and E2 of Part 1.\nThese Regulations apply where any of the sums obtained by (a), (b) or (c) is greater than or equal to 1.",
  "extent": null,
  "status": null,
  "version": "current",
  "annotations": [],
  "outstanding_effects": [],
  "provenance": {
    "source": "legislation.gov.uk",
    "source_url": "https://www.legislation.gov.uk/uksi/2015/483/schedule/1/paragraph/4",
    "retrieved_at": "2026-10-28T23:45:01.967239+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."
}