{
 "license": "CC BY 4.0 — Tremon Solutions, https://www.tremon.nl/gases/ch4",
 "generated": "2026-09-17",
 "key": "ch4",
 "name": "Methane",
 "formula": "CH₄",
 "formula_plain": "CH4",
 "iupac": "methane",
 "synonyms": [],
 "cas": "74-82-8",
 "ec_number": "200-812-7",
 "un_number": "1971",
 "un_shipping_name": "Methane, compressed or Natural gas, compressed, with a high methane content",
 "transport_class": "2.1 (Flammable Gases)",
 "pubchem_cid": 297,
 "molar_mass_g_mol": 16.04,
 "mg_m3_per_ppm_20c": 0.667,
 "boiling_point_c": -161.5,
 "sublimation_point_c": null,
 "melting_point_c": -182.47,
 "critical_temp_c": -82.6,
 "critical_pressure_bar": 45.95,
 "vapour_pressure_bar": null,
 "vapour_pressure_at_c": null,
 "density_gas_kg_m3": 0.7175,
 "density_condition": "0 °C, 1013 mbar",
 "relative_density_air": 0.56,
 "solubility_water": "36,7 ml/l at 20 °C",
 "appearance": "compressed gas, colourless, odourless",
 "odour": "odourless",
 "chemical_character": [
  "Extremely flammable gas. Forms hazardous explosive mixtures with air.",
  "Only slightly soluble in water.",
  "Gas is lighter than air."
 ],
 "hazard_class": "flammable (simple asphyxiant)",
 "ghs_classification": [
  "Flammable gases, Category 1; H220",
  "Gases under pressure, compressed gas; H280"
 ],
 "ghs_signal_word": "Danger",
 "ghs_hazard_statements": [
  "H220: Extremely flammable gas.",
  "H280: Contains gas under pressure; may explode if heated."
 ],
 "euh_statements": [],
 "nfpa704": {
  "health": 2,
  "flammability": 4,
  "instability": 0,
  "special": "SA"
 },
 "lel_vol_pct": 4.4,
 "uel_vol_pct": 17.0,
 "autoignition_c": 595.0,
 "temperature_class": "T1",
 "explosion_group": "IIA",
 "eu_ioelv": {
  "twa_8h_ppm": null,
  "twa_8h_mg_m3": null,
  "stel_15min_ppm": null,
  "stel_15min_mg_m3": null,
  "directive": null
 },
 "de_agw": {
  "twa_ppm": null,
  "twa_mg_m3": null,
  "source": "TRGS 900 via GESTIS"
 },
 "nl_grenswaarde": {
  "note": "Netherlands: wettelijke grenswaarden (Arboregeling, bijlage XIII) — check the SER grenswaarden database (https://www.ser.nl/nl/thema/arbeidsomstandigheden/grenswaarden) for the current legal value; EU IOELVs are transposed into it."
 },
 "niosh_rel": {
  "twa_ppm": null,
  "stel_or_ceiling_ppm": null,
  "raw": null
 },
 "osha_pel": null,
 "idlh_ppm": null,
 "idlh_raw": null,
 "gwp100": {
  "ar4": 25,
  "ar6": 27.9,
  "eu_fgas_2024_573_annex": 27.9
 },
 "atmospheric_lifetime_years": 11.8,
 "odp": 0,
 "gwp_note": null,
 "seveso_named": true,
 "health_effects": "Simple asphyxiant with no direct toxicity; the hazard is displacement of oxygen and explosion (LEL 4.4 vol%). Odourless — natural gas is odorised artificially.",
 "main_toxic_effects_gestis": "Acute: \nCold damage/frostbite following contact with refrigerated liquid or expanded gas; \nin high concentrations suffocating action due to displacement of oxygen \nChronic: \nNo substance-related effects known",
 "routes_of_exposure": "Main routes of exposure\nThe main intake pathway for methane (M.) is via the respiratory tract. \nRespiratory tract\nM. is absorbed via the lungs. In comparison with rats, pulmonary absorption in humans is less rapid, but the largest proportion of the dose retained in humans and animals is exhaled unchanged again. [8089, 454]\nSkin\nUptake through the skin seems to have no toxicological significance. \nBased on its physicochemical properties (gas with poor solubility in water), M. is not expected to penetrate the skin to a significant extent. \nGastrointestinal tract\nSwallowing of M. could only be possible as a refrigerated liquid, but even in this case absorption in the gastrointestinal tract is unlikely because of its high volatility.",
 "ir_absorption_band_um": "3.3 µm (ν₃ C–H stretch, 3019 cm⁻¹); 7.7 µm (ν₄, 1306 cm⁻¹)",
 "monitoring": [
  "NDIR (3.3 µm) is the modern choice for 0–100 %LEL and 0–100 vol%: no O₂ needed, immune to catalyst poisons (silicones, H₂S), fail-safe. Catalytic beads remain for legacy %LEL loops.",
  "Alarms 10 %LEL (pre) / 20 %LEL (main); sensors at ceiling level (lighter than air). LDAR under Reg. 2024/1787 needs quantification (ppm → %) plus leak localisation."
 ],
 "regulation_windows": [
  "Methane Regulation (EU) 2024/1787 — LDAR surveys, MRV; leaks ≥ 500 ppmv repaired: first attempt within 5 days, completed within 30 days (Art. 14(9)); importer MRV from 1 Jan 2027",
  "REPowerEU biomethane — 35 bcm/yr by 2030",
  "ATEX 2014/34/EU + EN 60079-29-1 for %LEL detectors"
 ],
 "tremon_products": [
  "IR·OEM CH₄ channel (%LEL / vol%)",
  "TRM-EX-IR (Ex db IIC T6)",
  "TRM-PGA biogas analyzer"
 ],
 "sources": [
  "https://gestis-database.dguv.de/data?name=010000",
  "https://pubchem.ncbi.nlm.nih.gov/compound/297",
  "IPCC AR6 WG1 Ch.7 Supplementary Material, Table 7.SM.7 (https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_Chapter07_SM.pdf)",
  "IPCC AR4 WG1 Ch.2, Table 2.14 (https://www.ipcc.ch/site/assets/uploads/2018/02/ar4-wg1-chapter2-1.pdf)",
  "Regulation (EU) 2024/573, Annex I/III (https://eur-lex.europa.eu/eli/reg/2024/573/oj)",
  "HITRAN/NIST IR band positions (approximate centre of the strongest band used for NDIR; https://hitran.org, https://webbook.nist.gov)"
 ]
}