{
  "url": "https://openlegislation.uk/control-of-substances-hazardous-to-health-regulations-1988/schedule-1",
  "json_url": "https://openlegislation.uk/control-of-substances-hazardous-to-health-regulations-1988/schedule-1.json",
  "legislation": "uksi/1988/1657",
  "legislation_title": "The Control of Substances Hazardous to Health Regulations 1988",
  "legislation_url": "https://openlegislation.uk/control-of-substances-hazardous-to-health-regulations-1988",
  "path": "schedule/1",
  "kind": "schedule",
  "number": "1",
  "heading": "LIST OF SUBSTANCES ASSIGNED MAXIMUM EXPOSURE LIMITS",
  "text": "Reference periods\nLong-term maximum exposure limit (8-hour TWA reference period)\nShort-term maximum exposure limit (10-minute reference period)\nppm\nppm\nSubstance\nFormula\nmg m—3\nmg m—3\n* Limit relates to cyclohexane soluble material\n† Vinyl chloride is also subject to an overriding annual maximum exposure limit of 3 ppm.\nAcrylonitrile\nCH2=CHCN\n2\n4\n—\n—\nArsenic & compounds, except arsine and lead arsenate (as As)\nAs\n—\n0.2\n—\n—\nButa—1, 3—diene\nCH2=CHCH=CH2\n10\n—\n—\n—\n2—Butoxyethanol\nC4H9OCH2CH2OH\n25\n120\n—\n—\nCadmium & cadmium compounds, except cadmium oxide fume and cadmium sulphide pigments (as Cd)\nCd\n—\n0.05\n—\n—\nCadmium oxide fume (as Cd)\nCdO\n—\n0.05\n—\n0.05\nCadmium sulphide pigments (respirable dust as Cd)\nCdS\n—\n0.04\n—\n—\nCarbon disulphide\nCS2\n10\n30\n—\n—\nDichloromethane\nCH2Cl2\n100\n350\n—\n—\n2,2'—Dichloro—4,4'—methylene dianiline (MbOCA)\nCH2(C6H3ClNH2)2\n—\n0.005\n—\n—\n2—Ethoxyethanol\nC2H5OCH2CH2OH\n10\n37\n—\n—\n2—Ethoxyethyl acetate\nC2H5OCH2CH2OOCCH3L\n10\n54\n—\n—\nEthylene dibromide\nBrCH2CH2Br\n1\n8\n—\n—\nEthylene oxide\nCH2CH2O\n5\n10\n—\n—\nFormaldehyde\nHCHO\n2\n2.5\n2\n2.5\nHydrogen cyanide\nHCN\n—\n—\n10\n10\nIsocyanates, all (as—NCO)\n—\n0.02\n—\n0.07\nMan-made mineral fibre\n—\n5\n—\n—\n1—Methoxypropan—2—ol\nCH3OCH2CHOHCH3\n100\n360\n—\n—\n2—Methoxyethanol\nCH3OCH2CH2OH\n5\n16\n—\n—\n2—Methoxyethyl acetate\nCH3COOCH2CH2OCH3\n5\n24\n—\n—\nRubber Process Dust\n—\n8\n—\n—\nRubber Fume\n—\n0.75\n—\n—\nStyrene\nC6H5CH=CH2\n100\n420\n250\n1050\n1,1,1—Trichloroethane\nCH3CCl3\n350\n1900\n450\n2450\nTrichloroethylene\nCCl2=CHCl\n100\n535\n150\n802\nVinyl chloride\nCH2=CHCl\n7\n—\n—\n—\nVinylidene chloride\nCH2=CCl2\n10\n40\n—\n—\nWood dust (hard wood)\n—\n5\n—\n—",
  "extent": null,
  "status": null,
  "version": "current",
  "annotations": [
    {
      "type": "footnote",
      "label": "f1",
      "text": "* Limit relates to cyclohexane soluble material"
    },
    {
      "type": "footnote",
      "label": "f2",
      "text": "† Vinyl chloride is also subject to an overriding annual maximum exposure limit of 3 ppm."
    }
  ],
  "outstanding_effects": [
    {
      "type": "replaced",
      "affecting": "uksi/1990/2026",
      "affecting_title": "The Control of Substances Hazardous to Health (Amendment) Regulations 1990"
    }
  ],
  "provenance": {
    "source": "legislation.gov.uk",
    "source_url": "https://www.legislation.gov.uk/uksi/1988/1657/schedule/1",
    "retrieved_at": "2026-10-29T15:57:35.141344+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."
}