{
  "url": "https://openlegislation.uk/dark-smoke-permitted-periods-regulations-1958/regulation-2",
  "json_url": "https://openlegislation.uk/dark-smoke-permitted-periods-regulations-1958/regulation-2.json",
  "legislation": "uksi/1958/498",
  "legislation_title": "The Dark Smoke (Permitted Periods) Regulations 1958",
  "legislation_url": "https://openlegislation.uk/dark-smoke-permitted-periods-regulations-1958",
  "path": "regulation/2",
  "kind": "regulation",
  "number": "2",
  "heading": null,
  "text": "(1) The Interpretation Act, 1889, applies to the interpretation of these regulations as it applies to the interpretation of an Act of Parliament.\n(2) In these regulations “the Act of 1956” means the Clean Air Act, 1956, and “black smoke” means smoke which, if compared in the appropriate manner with a chart of the type known at the date of the passing of the Act of 1956 as the Ringelmann Chart, would appear to be as dark as or darker than shade 4 on the chart.\n(3) Where a single boiler or unit of industrial plant is fired by more than one furnace discharging to the same chimney those furnaces shall, for the purposes of these regulations, be deemed to be one furnace.",
  "extent": null,
  "status": null,
  "version": "current",
  "annotations": [],
  "outstanding_effects": [],
  "provenance": {
    "source": "legislation.gov.uk",
    "source_url": "https://www.legislation.gov.uk/uksi/1958/498/regulation/2",
    "retrieved_at": "2026-10-30T01:03:34.826575+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."
}