{
  "name": "Gas group, temperature class and autoignition temperature by substance",
  "description": "Hazardous area (explosive atmosphere) classification of individual flammable gases, vapours and combustible dusts. Each record is one substance as classified by one publisher, giving the apparatus / gas group (IIA, IIB, IIC, IIB+H2 under IEC 60079 and ATEX, or Class I Group A/B/C/D under the US National Electrical Code), the temperature class (T1 to T6), and the autoignition temperature the publisher prints. Answers 'is toluene IIA or IIB', 'what temperature class is acetone', 'MEK autoignition temperature for explosion proof equipment', 'NEC Group C equivalent IEC gas group', 'what gas group is hydrogen sulphide', and 'ethylene gas group and T class'. Publishers disagree on the autoignition temperature of the same substance -- hydrogen is printed as 500 C, 520 C and 560 C by three different manufacturers, and ethylene as 450 C and 490 C -- and because the temperature class is derived from that number the disagreement changes which equipment is legal to install. Every value is quoted from the page that printed it and attributed, so the disagreements are visible rather than averaged away.",
  "url": "https://referencesource.org/hazardous-area-substance-classification/",
  "licence": "Facts extracted from freely published manufacturer and industry reference pages. Gas group and temperature class assignments are safety classifications and the underlying values are facts, not copyrightable expression. The authoritative documents (NFPA 497, IEC 60079-20-1) are not reproduced and were not opened -- the fact is taken, never the document. No bulk take from any single source: records come one or two substances at a time from five separate publishers.",
  "last_verified": "2026-08-06",
  "stale_after": "2028-08-05",
  "sources": [
    "https://www.e2s.com/guide-for-hazardous-areas/apparatus-groups-and-common-flammable-ga",
    "https://www.cortemgroup.com/en/news/the-zones-of-the-plant-the-groups-and-the-temperature-classes-of-gases",
    "https://ldpi-inc.com/resources/classification-codes/class-1-locations/",
    "https://exknowledge.com/pages/gas-groups.html"
  ],
  "records": [
    {
      "substance": "Di-ethyl ether",
      "classification_system": "IEC / ATEX",
      "group": "IIB",
      "temperature_class": "T4",
      "ignition_temperature_c": "160",
      "id": "160-iec-atex-di-ethyl-ether",
      "url": "https://referencesource.org/hazardous-area-substance-classification/160-iec-atex-di-ethyl-ether/",
      "source": "https://www.e2s.com/guide-for-hazardous-areas/apparatus-groups-and-common-flammable-ga",
      "source_quote": "Di-ethyl ether | T4 | IIB | 160",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "substance",
        "temperature_class"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Benzaldehyde",
      "classification_system": "IEC / ATEX",
      "group": "IIA",
      "temperature_class": "T4",
      "ignition_temperature_c": "192",
      "id": "192-iec-atex-benzaldehyde",
      "url": "https://referencesource.org/hazardous-area-substance-classification/192-iec-atex-benzaldehyde/",
      "source": "https://www.cortemgroup.com/en/news/the-zones-of-the-plant-the-groups-and-the-temperature-classes-of-gases",
      "source_quote": "Benzaldehyde, which has an auto-ignition temperature of 192\u00b0 C, will be classified in the T4 temperature class.",
      "verified_fields": [
        "ignition_temperature_c",
        "substance",
        "temperature_class"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Cyclohexane",
      "classification_system": "IEC / ATEX",
      "group": "IIA",
      "temperature_class": "T3",
      "ignition_temperature_c": "245",
      "id": "245-iec-atex-cyclohexane",
      "url": "https://referencesource.org/hazardous-area-substance-classification/245-iec-atex-cyclohexane/",
      "source": "https://www.e2s.com/guide-for-hazardous-areas/apparatus-groups-and-common-flammable-ga",
      "source_quote": "Cyclohexane | T3 | IIA | 245",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "substance",
        "temperature_class"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Gasoline",
      "classification_system": "IEC / ATEX",
      "group": "IIA",
      "ignition_temperature_c": "280",
      "ignition_temperature_f": "536",
      "id": "280-iec-atex-gasoline",
      "url": "https://referencesource.org/hazardous-area-substance-classification/280-iec-atex-gasoline/",
      "source": "https://ldpi-inc.com/resources/classification-codes/class-1-locations/",
      "source_quote": "Gasoline | D | 280 | 536 | 600 PSI | IIA",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "ignition_temperature_f",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Gasoline (petrol)",
      "classification_system": "IEC / ATEX",
      "group": "IIA",
      "temperature_class": "T3",
      "ignition_temperature_c": "280",
      "id": "280-iec-atex-gasoline-petrol",
      "url": "https://referencesource.org/hazardous-area-substance-classification/280-iec-atex-gasoline-petrol/",
      "source": "https://www.e2s.com/guide-for-hazardous-areas/apparatus-groups-and-common-flammable-ga",
      "source_quote": "Gasoline (petrol) | T3 | IIA | 280",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "substance",
        "temperature_class"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Gasoline",
      "classification_system": "NEC 500 (North America)",
      "group": "D",
      "ignition_temperature_c": "280",
      "ignition_temperature_f": "536",
      "id": "280-nec-500-north-america-gasoline",
      "url": "https://referencesource.org/hazardous-area-substance-classification/280-nec-500-north-america-gasoline/",
      "source": "https://ldpi-inc.com/resources/classification-codes/class-1-locations/",
      "source_quote": "Gasoline | D | 280 | 536 | 600 PSI | IIA",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "ignition_temperature_f",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Kerosene",
      "classification_system": "IEC / ATEX",
      "group": "IIA",
      "temperature_class": "T3",
      "ignition_temperature_c": "295",
      "id": "295-iec-atex-kerosene",
      "url": "https://referencesource.org/hazardous-area-substance-classification/295-iec-atex-kerosene/",
      "source": "https://www.e2s.com/guide-for-hazardous-areas/apparatus-groups-and-common-flammable-ga",
      "source_quote": "Kerosene | T3 | IIA | 295",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "substance",
        "temperature_class"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Acetylene",
      "classification_system": "IEC / ATEX",
      "group": "IIC",
      "temperature_class": "T2",
      "ignition_temperature_c": "305",
      "id": "305-iec-atex-acetylene",
      "url": "https://referencesource.org/hazardous-area-substance-classification/305-iec-atex-acetylene/",
      "source": "https://www.e2s.com/guide-for-hazardous-areas/apparatus-groups-and-common-flammable-ga",
      "source_quote": "Acetylene | T2 | IIC | 305",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "substance",
        "temperature_class"
      ],
      "derived_fields": [
        "classification_system"
      ],
      "also_reported": [
        {
          "field": "ignition_temperature_f",
          "value": "581",
          "source": "https://ldpi-inc.com/resources/classification-codes/class-1-locations/",
          "source_quote": "Acetylene | A | 305 | 581 | 6,000 PSI | IIC",
          "as_of": "2026-08-06"
        }
      ],
      "disagreements": []
    },
    {
      "substance": "Acetylene",
      "classification_system": "NEC 500 (North America)",
      "group": "A",
      "ignition_temperature_c": "305",
      "ignition_temperature_f": "581",
      "id": "305-nec-500-north-america-acetylene",
      "url": "https://referencesource.org/hazardous-area-substance-classification/305-nec-500-north-america-acetylene/",
      "source": "https://ldpi-inc.com/resources/classification-codes/class-1-locations/",
      "source_quote": "Acetylene | A | 305 | 581 | 6,000 PSI | IIC",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "ignition_temperature_f",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Ethanol (ethyl alcohol)",
      "classification_system": "IEC / ATEX",
      "group": "IIA",
      "temperature_class": "T2",
      "ignition_temperature_c": "365",
      "id": "365-iec-atex-ethanol-ethyl-alcohol",
      "url": "https://referencesource.org/hazardous-area-substance-classification/365-iec-atex-ethanol-ethyl-alcohol/",
      "source": "https://www.e2s.com/guide-for-hazardous-areas/apparatus-groups-and-common-flammable-ga",
      "source_quote": "Ethanol (ethyl alcohol) | T2 | IIA | 365",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "substance",
        "temperature_class"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Propan-1-ol (n-propyl alcohol)",
      "classification_system": "IEC / ATEX",
      "group": "IIB",
      "temperature_class": "T2",
      "ignition_temperature_c": "371",
      "id": "371-iec-atex-propan-1-ol-n-propyl-alcohol",
      "url": "https://referencesource.org/hazardous-area-substance-classification/371-iec-atex-propan-1-ol-n-propyl-alcohol/",
      "source": "https://www.e2s.com/guide-for-hazardous-areas/apparatus-groups-and-common-flammable-ga",
      "source_quote": "Propan-1-ol (n-propyl alcohol) | T2 | IIB | 371",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "substance",
        "temperature_class"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Coal dust (lignite)",
      "classification_system": "IEC / ATEX",
      "group": "IIIB",
      "ignition_temperature_c": "380",
      "layer_ignition_temperature_c": "225",
      "id": "380-iec-atex-coal-dust-lignite",
      "url": "https://referencesource.org/hazardous-area-substance-classification/380-iec-atex-coal-dust-lignite/",
      "source": "https://www.e2s.com/guide-for-hazardous-areas/apparatus-groups-and-common-flammable-ga",
      "source_quote": "Coal dust (lignite) | IIIB | 380 | 225",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "layer_ignition_temperature_c",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Propan-2-ol (iso-propyl alcohol)",
      "classification_system": "IEC / ATEX",
      "group": "IIA",
      "temperature_class": "T2",
      "ignition_temperature_c": "399",
      "id": "399-iec-atex-propan-2-ol-iso-propyl-alcohol",
      "url": "https://referencesource.org/hazardous-area-substance-classification/399-iec-atex-propan-2-ol-iso-propyl-alcohol/",
      "source": "https://www.e2s.com/guide-for-hazardous-areas/apparatus-groups-and-common-flammable-ga",
      "source_quote": "Propan-2-ol (iso-propyl alcohol) | T2 | IIA | 399",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "substance",
        "temperature_class"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Butane",
      "classification_system": "IEC / ATEX",
      "group": "IIA",
      "temperature_class": "T2",
      "ignition_temperature_c": "405",
      "id": "405-iec-atex-butane",
      "url": "https://referencesource.org/hazardous-area-substance-classification/405-iec-atex-butane/",
      "source": "https://www.e2s.com/guide-for-hazardous-areas/apparatus-groups-and-common-flammable-ga",
      "source_quote": "Butane | T2 | IIA | 405",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "substance",
        "temperature_class"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Methyl cellulose",
      "classification_system": "IEC / ATEX",
      "group": "IIIB",
      "ignition_temperature_c": "420",
      "layer_ignition_temperature_c": "320",
      "id": "420-iec-atex-methyl-cellulose",
      "url": "https://referencesource.org/hazardous-area-substance-classification/420-iec-atex-methyl-cellulose/",
      "source": "https://www.e2s.com/guide-for-hazardous-areas/apparatus-groups-and-common-flammable-ga",
      "source_quote": "Methyl cellulose | IIIB | 420 | 320",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "layer_ignition_temperature_c",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Polythene",
      "classification_system": "IEC / ATEX",
      "group": "IIIB",
      "ignition_temperature_c": "420",
      "layer_ignition_temperature_c": "(melts)",
      "id": "420-iec-atex-polythene",
      "url": "https://referencesource.org/hazardous-area-substance-classification/420-iec-atex-polythene/",
      "source": "https://www.e2s.com/guide-for-hazardous-areas/apparatus-groups-and-common-flammable-ga",
      "source_quote": "Polythene | IIIB | 420 | (melts)",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "layer_ignition_temperature_c",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Acetic acid",
      "classification_system": "IEC / ATEX",
      "group": "IIA",
      "temperature_class": "T1",
      "ignition_temperature_c": "427",
      "id": "427-iec-atex-acetic-acid",
      "url": "https://referencesource.org/hazardous-area-substance-classification/427-iec-atex-acetic-acid/",
      "source": "https://www.e2s.com/guide-for-hazardous-areas/apparatus-groups-and-common-flammable-ga",
      "source_quote": "Acetic acid | T1 | IIA | 427",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "substance",
        "temperature_class"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Ethylene",
      "classification_system": "IEC / ATEX",
      "group": "IIB",
      "ignition_temperature_c": "450",
      "ignition_temperature_f": "842",
      "id": "450-iec-atex-ethylene",
      "url": "https://referencesource.org/hazardous-area-substance-classification/450-iec-atex-ethylene/",
      "source": "https://ldpi-inc.com/resources/classification-codes/class-1-locations/",
      "source_quote": "Ethylene | C | 450 | 842 | 1,200 PSI | IIB",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "ignition_temperature_f",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Ethylene",
      "classification_system": "NEC 500 (North America)",
      "group": "C",
      "ignition_temperature_c": "450",
      "ignition_temperature_f": "842",
      "id": "450-nec-500-north-america-ethylene",
      "url": "https://referencesource.org/hazardous-area-substance-classification/450-nec-500-north-america-ethylene/",
      "source": "https://ldpi-inc.com/resources/classification-codes/class-1-locations/",
      "source_quote": "Ethylene | C | 450 | 842 | 1,200 PSI | IIB",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "ignition_temperature_f",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Starch",
      "classification_system": "IEC / ATEX",
      "group": "IIIB",
      "ignition_temperature_c": "460",
      "layer_ignition_temperature_c": "435",
      "id": "460-iec-atex-starch",
      "url": "https://referencesource.org/hazardous-area-substance-classification/460-iec-atex-starch/",
      "source": "https://www.e2s.com/guide-for-hazardous-areas/apparatus-groups-and-common-flammable-ga",
      "source_quote": "Starch | IIIB | 460 | 435",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "layer_ignition_temperature_c",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Xylene",
      "classification_system": "IEC / ATEX",
      "group": "IIA",
      "temperature_class": "T1",
      "ignition_temperature_c": "463",
      "id": "463-iec-atex-xylene",
      "url": "https://referencesource.org/hazardous-area-substance-classification/463-iec-atex-xylene/",
      "source": "https://www.e2s.com/guide-for-hazardous-areas/apparatus-groups-and-common-flammable-ga",
      "source_quote": "Xylene | T1 | IIA | 463",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "substance",
        "temperature_class"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Acetone",
      "classification_system": "IEC / ATEX",
      "group": "IIA",
      "temperature_class": "T1",
      "ignition_temperature_c": "465",
      "id": "465-iec-atex-acetone",
      "url": "https://referencesource.org/hazardous-area-substance-classification/465-iec-atex-acetone/",
      "source": "https://www.e2s.com/guide-for-hazardous-areas/apparatus-groups-and-common-flammable-ga",
      "source_quote": "Acetone | T1 | IIA | 465",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "substance",
        "temperature_class"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Methanol (methyl alcohol)",
      "classification_system": "IEC / ATEX",
      "group": "IIA",
      "temperature_class": "T2",
      "ignition_temperature_c": "470",
      "id": "470-iec-atex-methanol-methyl-alcohol",
      "url": "https://referencesource.org/hazardous-area-substance-classification/470-iec-atex-methanol-methyl-alcohol/",
      "source": "https://www.e2s.com/guide-for-hazardous-areas/apparatus-groups-and-common-flammable-ga",
      "source_quote": "Methanol (methyl alcohol) | T2 | IIA | 470",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "substance",
        "temperature_class"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Propane",
      "classification_system": "IEC / ATEX",
      "group": "IIA",
      "temperature_class": "T1",
      "ignition_temperature_c": "470",
      "id": "470-iec-atex-propane",
      "url": "https://referencesource.org/hazardous-area-substance-classification/470-iec-atex-propane/",
      "source": "https://www.e2s.com/guide-for-hazardous-areas/apparatus-groups-and-common-flammable-ga",
      "source_quote": "Propane | T1 | IIA | 470",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "substance",
        "temperature_class"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Ethylene",
      "classification_system": "IEC / ATEX",
      "group": "IIB",
      "temperature_class": "T2",
      "ignition_temperature_c": "490",
      "id": "490-iec-atex-ethylene",
      "url": "https://referencesource.org/hazardous-area-substance-classification/490-iec-atex-ethylene/",
      "source": "https://www.e2s.com/guide-for-hazardous-areas/apparatus-groups-and-common-flammable-ga",
      "source_quote": "Ethylene | T2 | IIB | 490",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "substance",
        "temperature_class"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Flour",
      "classification_system": "IEC / ATEX",
      "group": "IIIB",
      "ignition_temperature_c": "490",
      "layer_ignition_temperature_c": "340",
      "id": "490-iec-atex-flour",
      "url": "https://referencesource.org/hazardous-area-substance-classification/490-iec-atex-flour/",
      "source": "https://www.e2s.com/guide-for-hazardous-areas/apparatus-groups-and-common-flammable-ga",
      "source_quote": "Flour | IIIB | 490 | 340",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "layer_ignition_temperature_c",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Sugar",
      "classification_system": "IEC / ATEX",
      "group": "IIIB",
      "ignition_temperature_c": "490",
      "layer_ignition_temperature_c": "460",
      "id": "490-iec-atex-sugar",
      "url": "https://referencesource.org/hazardous-area-substance-classification/490-iec-atex-sugar/",
      "source": "https://www.e2s.com/guide-for-hazardous-areas/apparatus-groups-and-common-flammable-ga",
      "source_quote": "Sugar | IIIB | 490 | 460",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "layer_ignition_temperature_c",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Hydrogen",
      "classification_system": "IEC / ATEX",
      "group": "IIC",
      "temperature_class": "T1",
      "ignition_temperature_c": "500",
      "id": "500-iec-atex-hydrogen",
      "url": "https://referencesource.org/hazardous-area-substance-classification/500-iec-atex-hydrogen/",
      "source": "https://www.e2s.com/guide-for-hazardous-areas/apparatus-groups-and-common-flammable-ga",
      "source_quote": "Hydrogen | T1 | IIC | 500",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "substance",
        "temperature_class"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Methyl ethyl ketone (MEK)",
      "classification_system": "IEC / ATEX",
      "group": "IIB",
      "temperature_class": "T2",
      "ignition_temperature_c": "505",
      "id": "505-iec-atex-methyl-ethyl-ketone-mek",
      "url": "https://referencesource.org/hazardous-area-substance-classification/505-iec-atex-methyl-ethyl-ketone-mek/",
      "source": "https://www.e2s.com/guide-for-hazardous-areas/apparatus-groups-and-common-flammable-ga",
      "source_quote": "Methyl ethyl ketone (MEK) | T2 | IIB | 505",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "substance",
        "temperature_class"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Grain dust",
      "classification_system": "IEC / ATEX",
      "group": "IIIB",
      "ignition_temperature_c": "510",
      "layer_ignition_temperature_c": "300",
      "id": "510-iec-atex-grain-dust",
      "url": "https://referencesource.org/hazardous-area-substance-classification/510-iec-atex-grain-dust/",
      "source": "https://www.e2s.com/guide-for-hazardous-areas/apparatus-groups-and-common-flammable-ga",
      "source_quote": "Grain dust | IIIB | 510 | 300",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "layer_ignition_temperature_c",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Hydrogen",
      "classification_system": "IEC / ATEX",
      "group": "IIC",
      "ignition_temperature_c": "520",
      "ignition_temperature_f": "968",
      "id": "520-iec-atex-hydrogen",
      "url": "https://referencesource.org/hazardous-area-substance-classification/520-iec-atex-hydrogen/",
      "source": "https://ldpi-inc.com/resources/classification-codes/class-1-locations/",
      "source_quote": "Hydrogen | B | 520 | 968 | 6,000 PSI | IIC",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "ignition_temperature_f",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Hydrogen",
      "classification_system": "NEC 500 (North America)",
      "group": "B",
      "ignition_temperature_c": "520",
      "ignition_temperature_f": "968",
      "id": "520-nec-500-north-america-hydrogen",
      "url": "https://referencesource.org/hazardous-area-substance-classification/520-nec-500-north-america-hydrogen/",
      "source": "https://ldpi-inc.com/resources/classification-codes/class-1-locations/",
      "source_quote": "Hydrogen | B | 520 | 968 | 6,000 PSI | IIC",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "ignition_temperature_f",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Phenolic resin",
      "classification_system": "IEC / ATEX",
      "group": "IIIB",
      "ignition_temperature_c": "530",
      "layer_ignition_temperature_c": ">450",
      "id": "530-iec-atex-phenolic-resin",
      "url": "https://referencesource.org/hazardous-area-substance-classification/530-iec-atex-phenolic-resin/",
      "source": "https://www.e2s.com/guide-for-hazardous-areas/apparatus-groups-and-common-flammable-ga",
      "source_quote": "Phenolic resin | IIIB | 530 | >450",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "layer_ignition_temperature_c",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Toluene",
      "classification_system": "IEC / ATEX",
      "group": "IIA",
      "temperature_class": "T1",
      "ignition_temperature_c": "535",
      "id": "535-iec-atex-toluene",
      "url": "https://referencesource.org/hazardous-area-substance-classification/535-iec-atex-toluene/",
      "source": "https://www.e2s.com/guide-for-hazardous-areas/apparatus-groups-and-common-flammable-ga",
      "source_quote": "Toluene | T1 | IIA | 535",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "substance",
        "temperature_class"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Hydrogen",
      "classification_system": "IEC / ATEX",
      "group": "IIC",
      "temperature_class": "T1",
      "ignition_temperature_c": "560",
      "id": "560-iec-atex-hydrogen",
      "url": "https://referencesource.org/hazardous-area-substance-classification/560-iec-atex-hydrogen/",
      "source": "https://www.cortemgroup.com/en/news/the-zones-of-the-plant-the-groups-and-the-temperature-classes-of-gases",
      "source_quote": "Hydrogen, which has an auto-ignition temperature of 560\u00b0 C, will be classified in the T1 temperature class.",
      "verified_fields": [
        "ignition_temperature_c",
        "substance",
        "temperature_class"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Methane (natural gas) (non-mining)",
      "classification_system": "IEC / ATEX",
      "group": "IIA",
      "temperature_class": "T1",
      "ignition_temperature_c": "580",
      "id": "580-iec-atex-methane-natural-gas-non-mining",
      "url": "https://referencesource.org/hazardous-area-substance-classification/580-iec-atex-methane-natural-gas-non-mining/",
      "source": "https://www.e2s.com/guide-for-hazardous-areas/apparatus-groups-and-common-flammable-ga",
      "source_quote": "Methane (natural gas) (non-mining) | T1 | IIA | 580",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "substance",
        "temperature_class"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Aluminium",
      "classification_system": "IEC / ATEX",
      "group": "IIIC",
      "ignition_temperature_c": "590",
      "layer_ignition_temperature_c": ">450",
      "id": "590-iec-atex-aluminium",
      "url": "https://referencesource.org/hazardous-area-substance-classification/590-iec-atex-aluminium/",
      "source": "https://www.e2s.com/guide-for-hazardous-areas/apparatus-groups-and-common-flammable-ga",
      "source_quote": "Aluminium | IIIC | 590 | >450",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "layer_ignition_temperature_c",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Ammonia",
      "classification_system": "IEC / ATEX",
      "group": "IIA",
      "temperature_class": "T1",
      "ignition_temperature_c": "651",
      "id": "651-iec-atex-ammonia",
      "url": "https://referencesource.org/hazardous-area-substance-classification/651-iec-atex-ammonia/",
      "source": "https://www.e2s.com/guide-for-hazardous-areas/apparatus-groups-and-common-flammable-ga",
      "source_quote": "Ammonia | T1 | IIA | 651",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "substance",
        "temperature_class"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "PVC",
      "classification_system": "IEC / ATEX",
      "group": "IIIB",
      "ignition_temperature_c": "700",
      "layer_ignition_temperature_c": ">450",
      "id": "700-iec-atex-pvc",
      "url": "https://referencesource.org/hazardous-area-substance-classification/700-iec-atex-pvc/",
      "source": "https://www.e2s.com/guide-for-hazardous-areas/apparatus-groups-and-common-flammable-ga",
      "source_quote": "PVC | IIIB | 700 | >450",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "layer_ignition_temperature_c",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Soot",
      "classification_system": "IEC / ATEX",
      "group": "IIIB",
      "ignition_temperature_c": "810",
      "layer_ignition_temperature_c": "570",
      "id": "810-iec-atex-soot",
      "url": "https://referencesource.org/hazardous-area-substance-classification/810-iec-atex-soot/",
      "source": "https://www.e2s.com/guide-for-hazardous-areas/apparatus-groups-and-common-flammable-ga",
      "source_quote": "Soot | IIIB | 810 | 570",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "layer_ignition_temperature_c",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Carbon Disulphine",
      "classification_system": "IEC / ATEX",
      "group": "IIC",
      "temperature_class": "T6",
      "ignition_temperature_c": "95",
      "id": "95-iec-atex-carbon-disulphine",
      "url": "https://referencesource.org/hazardous-area-substance-classification/95-iec-atex-carbon-disulphine/",
      "source": "https://www.e2s.com/guide-for-hazardous-areas/apparatus-groups-and-common-flammable-ga",
      "source_quote": "Carbon Disulphine | T6 | IIC | 95",
      "verified_fields": [
        "group",
        "ignition_temperature_c",
        "substance",
        "temperature_class"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Acetone",
      "classification_system": "IEC / ATEX",
      "group": "IIA",
      "id": "iec-atex-acetone",
      "url": "https://referencesource.org/hazardous-area-substance-classification/iec-atex-acetone/",
      "source": "https://exknowledge.com/pages/gas-groups.html",
      "source_quote": "IIA | >0.90 | >0.80 | Methane, propane, butane, acetone, ethanol, benzene, diesel, ammonia",
      "verified_fields": [
        "group",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Acetylene",
      "classification_system": "IEC / ATEX",
      "group": "IIC",
      "id": "iec-atex-acetylene",
      "url": "https://referencesource.org/hazardous-area-substance-classification/iec-atex-acetylene/",
      "source": "https://exknowledge.com/pages/gas-groups.html",
      "source_quote": "IIC | Hydrogen, acetylene, carbon disulphide",
      "verified_fields": [
        "group",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Ammonia",
      "classification_system": "IEC / ATEX",
      "group": "IIA",
      "id": "iec-atex-ammonia",
      "url": "https://referencesource.org/hazardous-area-substance-classification/iec-atex-ammonia/",
      "source": "https://exknowledge.com/pages/gas-groups.html",
      "source_quote": "IIA | >0.90 | >0.80 | Methane, propane, butane, acetone, ethanol, benzene, diesel, ammonia",
      "verified_fields": [
        "group",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Benzene",
      "classification_system": "IEC / ATEX",
      "group": "IIA",
      "id": "iec-atex-benzene",
      "url": "https://referencesource.org/hazardous-area-substance-classification/iec-atex-benzene/",
      "source": "https://exknowledge.com/pages/gas-groups.html",
      "source_quote": "IIA | >0.90 | >0.80 | Methane, propane, butane, acetone, ethanol, benzene, diesel, ammonia",
      "verified_fields": [
        "group",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Butane",
      "classification_system": "IEC / ATEX",
      "group": "IIA",
      "id": "iec-atex-butane",
      "url": "https://referencesource.org/hazardous-area-substance-classification/iec-atex-butane/",
      "source": "https://exknowledge.com/pages/gas-groups.html",
      "source_quote": "IIA | >0.90 | >0.80 | Methane, propane, butane, acetone, ethanol, benzene, diesel, ammonia",
      "verified_fields": [
        "group",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Carbon disulphide",
      "classification_system": "IEC / ATEX",
      "group": "IIC",
      "id": "iec-atex-carbon-disulphide",
      "url": "https://referencesource.org/hazardous-area-substance-classification/iec-atex-carbon-disulphide/",
      "source": "https://exknowledge.com/pages/gas-groups.html",
      "source_quote": "IIC | Hydrogen, acetylene, carbon disulphide",
      "verified_fields": [
        "group",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Diesel",
      "classification_system": "IEC / ATEX",
      "group": "IIA",
      "id": "iec-atex-diesel",
      "url": "https://referencesource.org/hazardous-area-substance-classification/iec-atex-diesel/",
      "source": "https://exknowledge.com/pages/gas-groups.html",
      "source_quote": "IIA | >0.90 | >0.80 | Methane, propane, butane, acetone, ethanol, benzene, diesel, ammonia",
      "verified_fields": [
        "group",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Diethyl ether",
      "classification_system": "IEC / ATEX",
      "group": "IIB",
      "id": "iec-atex-diethyl-ether",
      "url": "https://referencesource.org/hazardous-area-substance-classification/iec-atex-diethyl-ether/",
      "source": "https://exknowledge.com/pages/gas-groups.html",
      "source_quote": "IIB | 0.50\u20130.90 | 0.45\u20130.80 | Ethylene, hydrogen sulphide, diethyl ether, ethylene oxide, town gas",
      "verified_fields": [
        "group",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Ethanol",
      "classification_system": "IEC / ATEX",
      "group": "IIA",
      "id": "iec-atex-ethanol",
      "url": "https://referencesource.org/hazardous-area-substance-classification/iec-atex-ethanol/",
      "source": "https://exknowledge.com/pages/gas-groups.html",
      "source_quote": "IIA | >0.90 | >0.80 | Methane, propane, butane, acetone, ethanol, benzene, diesel, ammonia",
      "verified_fields": [
        "group",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Ethylene",
      "classification_system": "IEC / ATEX",
      "group": "IIB",
      "id": "iec-atex-ethylene",
      "url": "https://referencesource.org/hazardous-area-substance-classification/iec-atex-ethylene/",
      "source": "https://exknowledge.com/pages/gas-groups.html",
      "source_quote": "IIB | 0.50\u20130.90 | 0.45\u20130.80 | Ethylene, hydrogen sulphide, diethyl ether, ethylene oxide, town gas",
      "verified_fields": [
        "group",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Ethylene oxide",
      "classification_system": "IEC / ATEX",
      "group": "IIB",
      "id": "iec-atex-ethylene-oxide",
      "url": "https://referencesource.org/hazardous-area-substance-classification/iec-atex-ethylene-oxide/",
      "source": "https://exknowledge.com/pages/gas-groups.html",
      "source_quote": "IIB | 0.50\u20130.90 | 0.45\u20130.80 | Ethylene, hydrogen sulphide, diethyl ether, ethylene oxide, town gas",
      "verified_fields": [
        "group",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Hydrogen",
      "classification_system": "IEC / ATEX",
      "group": "IIC",
      "id": "iec-atex-hydrogen",
      "url": "https://referencesource.org/hazardous-area-substance-classification/iec-atex-hydrogen/",
      "source": "https://exknowledge.com/pages/gas-groups.html",
      "source_quote": "IIC | Hydrogen, acetylene, carbon disulphide",
      "verified_fields": [
        "group",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Hydrogen sulphide",
      "classification_system": "IEC / ATEX",
      "group": "IIB",
      "id": "iec-atex-hydrogen-sulphide",
      "url": "https://referencesource.org/hazardous-area-substance-classification/iec-atex-hydrogen-sulphide/",
      "source": "https://exknowledge.com/pages/gas-groups.html",
      "source_quote": "IIB | 0.50\u20130.90 | 0.45\u20130.80 | Ethylene, hydrogen sulphide, diethyl ether, ethylene oxide, town gas",
      "verified_fields": [
        "group",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Methane",
      "classification_system": "IEC / ATEX",
      "group": "IIA",
      "id": "iec-atex-methane",
      "url": "https://referencesource.org/hazardous-area-substance-classification/iec-atex-methane/",
      "source": "https://exknowledge.com/pages/gas-groups.html",
      "source_quote": "IIA | >0.90 | >0.80 | Methane, propane, butane, acetone, ethanol, benzene, diesel, ammonia",
      "verified_fields": [
        "group",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "n-Hexane",
      "classification_system": "IEC / ATEX",
      "group": "IIA",
      "id": "iec-atex-n-hexane",
      "url": "https://referencesource.org/hazardous-area-substance-classification/iec-atex-n-hexane/",
      "source": "https://exknowledge.com/pages/gas-groups.html",
      "source_quote": "Group IIA: Methane (CH\u2084) \u2014 natural gas, biogas Propane (C\u2083H\u2088) \u2014 LPG Butane (C\u2084H\u2081\u2080) \u2014 LPG Acetone \u2014 solvents Ethanol \u2014 pharmaceutical, food/beverage Benzene, toluene, xylene \u2014 petrochemical Ammonia (NH\u2083) \u2014 refrigeration, agriculture n-Hexane \u2014 extraction processes",
      "verified_fields": [
        "group",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Propane",
      "classification_system": "IEC / ATEX",
      "group": "IIA",
      "id": "iec-atex-propane",
      "url": "https://referencesource.org/hazardous-area-substance-classification/iec-atex-propane/",
      "source": "https://exknowledge.com/pages/gas-groups.html",
      "source_quote": "IIA | >0.90 | >0.80 | Methane, propane, butane, acetone, ethanol, benzene, diesel, ammonia",
      "verified_fields": [
        "group",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Toluene",
      "classification_system": "IEC / ATEX",
      "group": "IIA",
      "id": "iec-atex-toluene",
      "url": "https://referencesource.org/hazardous-area-substance-classification/iec-atex-toluene/",
      "source": "https://exknowledge.com/pages/gas-groups.html",
      "source_quote": "Group IIA: Methane (CH\u2084) \u2014 natural gas, biogas Propane (C\u2083H\u2088) \u2014 LPG Butane (C\u2084H\u2081\u2080) \u2014 LPG Acetone \u2014 solvents Ethanol \u2014 pharmaceutical, food/beverage Benzene, toluene, xylene \u2014 petrochemical Ammonia (NH\u2083) \u2014 refrigeration, agriculture n-Hexane \u2014 extraction processes",
      "verified_fields": [
        "group",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Town gas",
      "classification_system": "IEC / ATEX",
      "group": "IIB",
      "id": "iec-atex-town-gas",
      "url": "https://referencesource.org/hazardous-area-substance-classification/iec-atex-town-gas/",
      "source": "https://exknowledge.com/pages/gas-groups.html",
      "source_quote": "IIB | 0.50\u20130.90 | 0.45\u20130.80 | Ethylene, hydrogen sulphide, diethyl ether, ethylene oxide, town gas",
      "verified_fields": [
        "group",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    },
    {
      "substance": "Xylene",
      "classification_system": "IEC / ATEX",
      "group": "IIA",
      "id": "iec-atex-xylene",
      "url": "https://referencesource.org/hazardous-area-substance-classification/iec-atex-xylene/",
      "source": "https://exknowledge.com/pages/gas-groups.html",
      "source_quote": "Group IIA: Methane (CH\u2084) \u2014 natural gas, biogas Propane (C\u2083H\u2088) \u2014 LPG Butane (C\u2084H\u2081\u2080) \u2014 LPG Acetone \u2014 solvents Ethanol \u2014 pharmaceutical, food/beverage Benzene, toluene, xylene \u2014 petrochemical Ammonia (NH\u2083) \u2014 refrigeration, agriculture n-Hexane \u2014 extraction processes",
      "verified_fields": [
        "group",
        "substance"
      ],
      "derived_fields": [
        "classification_system"
      ]
    }
  ]
}