You are using an unsupported browser. Please upgrade your browser to a newer version to get the best experience on Toxin, Toxin Target Database.
Record Information
Creation Date2009-03-06 18:58:01 UTC
Update Date2014-12-24 20:21:01 UTC
Accession NumberT3D0066
Common NameMethane
ClassSmall Molecule
DescriptionMethane (CH4), is a gas produced by a group of colonic anaerobes, absorbed from the colon and excreted in expired air. As a result, breath CH4 excretion can be used as an indicator of the in situ activity of the methanogenic flora. All CH4 produced in human beings is a metabolic product of intestinal bacteria, and about 50% of CH4 produced in the gut is absorbed and excreted in expired air. Because there appears to be no catabolism of this gas by other colonic organisms or host cells, breath CH4 measurements provide a rapid, simple means of semi quantitatively assessing the ongoing in situ metabolism of the methanogenic flora. It could seem likely that the intracolonic activity of a variety of bacteria similarly might be assessed quantitatively via analysis of expired air. However, the application of this methodology has been confounded by the rapid catabolism of many volatile bacterial products by other bacteria or human tissue. A striking aspect of the studies of breath CH4 measurements is the enormous individual variations in the excretion of this gas. Virtually all children under 5 years of age and 66% of the adult population do not exhale appreciable quantities of CH4. The remaining 34% of the adult population has appreciable breath methane concentrations of up to 80 ppm (mean, 15.2 ppm; median, 11.8 ppm). On this basis the population can be divided into CH4 producers or nonproducers, although a more accurate term would be to define subjects as being low or high CH4 producers. The primary methanogen present in the human colon, Methanobrevibacter smithii, produces methane via a reaction that relies entirely on H2 produced by other organisms to reduce CO2 to CH4. Thus, breath CH4 concentrations might be expected to mirror breath H2 concentrations; however, the high levels of CH4 observed in the fasting state may result from H2 derived from endogenous rather than dietary substrates. A diverse assortment of conditions has been associated with a high prevalence of methane producers including diverticulosis, cystic fibrosis, high fasting serum cholesterol levels, encopresis in children, and aorto-iliac vascular disease, whereas obesity (measured as skin-fold thickness) was related inversely to methane production. The challenge that remains is to determine to what extent methanogens actively influence body physiology vs. simply serve as passive indicators of colonic function. (22)
Compound Type
  • Food Toxin
  • Fuel
  • Industrial Precursor/Intermediate
  • Industrial/Workplace Toxin
  • Metabolite
  • Natural Compound
  • Organic Compound
Chemical Structure
Marsh gas
Methyl hydride
Chemical FormulaCH4
Average Molecular Mass16.043 g/mol
Monoisotopic Mass16.031 g/mol
CAS Registry Number74-82-8
IUPAC Namemethane
Traditional Namemethane
InChI IdentifierInChI=1S/CH4/h1H4
Chemical Taxonomy
Description belongs to the class of organic compounds known as alkanes. These are acyclic branched or unbranched hydrocarbons having the general formula CnH2n+2 , and therefore consisting entirely of hydrogen atoms and saturated carbon atoms.
KingdomOrganic compounds
Super ClassHydrocarbons
ClassSaturated hydrocarbons
Sub ClassAlkanes
Direct ParentAlkanes
Alternative ParentsNot Available
  • Acyclic alkane
  • Alkane
  • Aliphatic acyclic compound
Molecular FrameworkAliphatic acyclic compounds
External Descriptors
Biological Properties
StatusDetected and Not Quantified
Cellular Locations
  • Cytoplasm
  • Extracellular
Biofluid LocationsNot Available
Tissue Locations
  • Adipose Tissue
  • Fibroblasts
  • Intestine
  • Kidney
  • Liver
  • Muscle
  • Platelet
PathwaysNot Available
Biological Roles
Chemical Roles
Physical Properties
AppearanceColorless gas.
Experimental Properties
Melting Point-182.4°C
Boiling PointNot Available
Solubility0.022 mg/mL at 25°C
Predicted Properties
Water Solubility0 g/LALOGPS
Physiological Charge0ChemAxon
Hydrogen Acceptor Count0ChemAxon
Hydrogen Donor Count0ChemAxon
Polar Surface Area0 ŲChemAxon
Rotatable Bond Count0ChemAxon
Refractivity6.35 m³·mol⁻¹ChemAxon
Polarizability2.59 ųChemAxon
Number of Rings0ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleYesChemAxon
MDDR-like RuleYesChemAxon
Spectrum TypeDescriptionSplash KeyView
GC-MSGC-MS Spectrum - EI-B (Non-derivatized)splash10-014i-9000000000-42e2bf163f3e1178d2b7JSpectraViewer | MoNA
GC-MSGC-MS Spectrum - EI-B (Non-derivatized)splash10-014i-9000000000-42e2bf163f3e1178d2b7JSpectraViewer | MoNA
Predicted GC-MSPredicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positivesplash10-014i-9000000000-c8167f7817582bf388a4JSpectraViewer
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Positivesplash10-014i-9000000000-9d8342b86bcfe423c16eJSpectraViewer
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Positivesplash10-014i-9000000000-9d8342b86bcfe423c16eJSpectraViewer
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Positivesplash10-014i-9000000000-9d8342b86bcfe423c16eJSpectraViewer
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Negativesplash10-014i-9000000000-c888af3d1348fef91ee6JSpectraViewer
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Negativesplash10-014i-9000000000-c888af3d1348fef91ee6JSpectraViewer
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Negativesplash10-014i-9000000000-c888af3d1348fef91ee6JSpectraViewer
MSMass Spectrum (Electron Ionization)splash10-014i-9000000000-349ab823203cc040e2eeJSpectraViewer | MoNA
1D NMR1H NMR SpectrumNot AvailableJSpectraViewer
Toxicity Profile
Route of ExposureInhalation (24)
Mechanism of ToxicityMethane is an asphyxiant and displaces oxygen in enclosed spaces. At high enough concentrations, oxygen depletion may cause asphyxiation. Low concentrations of surrounding oxygen results in deficient oxygen to the organs, compounded by increased oxygen exhalation during respiration. This results in generalized hypoxia and possibly death. (23, 1)
MetabolismMethane is biologically inactive. (24)
Toxicity ValuesLC50: 326 gm/m3 over 2 hours (Inhalation, Mouse) (25)
Lethal DoseNot Available
Carcinogenicity (IARC Classification)No indication of carcinogenicity to humans (not listed by IARC).
Uses/SourcesMethane is the major component of natural gas, which is found in geological deposits known as natural gas fields and used as vehicle fuel in its compressed form. Methane may be burned to produce electricity and is often piped into homes for domestic heating and cooking purposes. Methane is also used in industrial processes to produce chemicals such as hydrogen, methanol, acetic acid, and acetic anhydride. (23)
Minimum Risk LevelNot Available
Health EffectsMethane is an asphyxiant and displaces oxygen in enclosed spaces. At high enough concentrations, oxygen depletion may cause asphyxiation, resulting in generalized hypoxia and possibly death. (23, 24)
SymptomsSymptoms of methane asphyxiation include nausea, vomiting, difficulty breathing, irregular heartbeat, headache, drowsiness, fatigue, dizziness, disorientation, mood swings, tingling sensation, loss of coordination, suffocation, convulsions, unconsciousness, coma, and possibly death. (25)
TreatmentAsphyxiation should be treated by moving the affected person to an uncontaminated area, then giving artificial respiration and administering oxygen, if necessary. (25)
Normal Concentrations
Not Available
Abnormal Concentrations
Not Available
DrugBank IDNot Available
PubChem Compound ID297
ChemSpider ID291
UniProt IDNot Available
OMIM ID250650 , 609236
ChEBI ID16183
BioCyc IDCH4
CTD IDD008697
Stitch IDMethane
ACToR ID3261
Wikipedia LinkMethane
Synthesis ReferenceTamaura, Yutaka. Method for manufacture of methane. Jpn. Kokai Tokkyo Koho (1994), 9 pp.
General References
  1. Watanabe T, Morita M: Asphyxia due to oxygen deficiency by gaseous substances. Forensic Sci Int. 1998 Aug 31;96(1):47-59. [9800365 ]
  2. Minh NH, Someya M, Minh TB, Kunisue T, Iwata H, Watanabe M, Tanabe S, Viet PH, Tuyen BC: Persistent organochlorine residues in human breast milk from Hanoi and Hochiminh City, Vietnam: contamination, accumulation kinetics and risk assessment for infants. Environ Pollut. 2004 Jun;129(3):431-41. [15016464 ]
  3. Castelain P, Van Hummelen P, Deleener A, Kirsch-Volders M: Automated detection of cytochalasin-B blocked binucleated lymphocytes for scoring micronuclei. Mutagenesis. 1993 Jul;8(4):285-93. [7690875 ]
  4. Rumessen JJ, Gudmand-Hoyer E: Fructans of chicory: intestinal transport and fermentation of different chain lengths and relation to fructose and sorbitol malabsorption. Am J Clin Nutr. 1998 Aug;68(2):357-64. [9701194 ]
  5. Florin TH, Woods HJ: Inhibition of methanogenesis by human bile. Gut. 1995 Sep;37(3):418-21. [7590441 ]
  6. Tsai WB, Shi Q, Grunkemeier JM, McFarland C, Horbett TA: Platelet adhesion to radiofrequency glow-discharge-deposited fluorocarbon polymers preadsorbed with selectively depleted plasmas show the primary role of fibrinogen. J Biomater Sci Polym Ed. 2004;15(7):817-40. [15318794 ]
  7. Bernalier A, Willems A, Leclerc M, Rochet V, Collins MD: Ruminococcus hydrogenotrophicus sp. nov., a new H2/CO2-utilizing acetogenic bacterium isolated from human feces. Arch Microbiol. 1996 Sep;166(3):176-83. [8703194 ]
  8. Ringvoll J, Nordstrand LM, Vagbo CB, Talstad V, Reite K, Aas PA, Lauritzen KH, Liabakk NB, Bjork A, Doughty RW, Falnes PO, Krokan HE, Klungland A: Repair deficient mice reveal mABH2 as the primary oxidative demethylase for repairing 1meA and 3meC lesions in DNA. EMBO J. 2006 May 17;25(10):2189-98. Epub 2006 Apr 27. [16642038 ]
  9. Poyart C, Bursaux E, Freminet A, Bertin M: Interactions of short chain aliphatic hydrocarbons with human blood and haemoglobin A solutions. Biomedicine. 1976 Jul;25(6):224-7. [963185 ]
  10. Rabot S, Viso M, Martin F, Blanquie JP, Popot F, Bensaada M, Vaissade P, Searby N, Szylit O: Effects of chair-restraint on gastrointestinal transit time and colonic fermentation in male rhesus monkey (Macaca mulatta). J Med Primatol. 1997 Aug;26(4):190-5. [9416569 ]
  11. Kresimon J, Gruter UM, Hirner AV: HG/LT-GC/ICP-MS coupling for identification of metal(loid) species in human urine after fish consumption. Fresenius J Anal Chem. 2001 Nov;371(5):586-90. [11767883 ]
  12. Nakamura M, Ueki S, Hara H, Arata T: Calcium structural transition of human cardiac troponin C in reconstituted muscle fibres as studied by site-directed spin labelling. J Mol Biol. 2005 Apr 22;348(1):127-37. [15808858 ]
  13. Kayar SR, Miller TL, Wolin MJ, Aukhert EO, Axley MJ, Kiesow LA: Decompression sickness risk in rats by microbial removal of dissolved gas. Am J Physiol. 1998 Sep;275(3 Pt 2):R677-82. [9728062 ]
  14. Chien YH, Bau DT, Jan KY: Nitric oxide inhibits DNA-adduct excision in nucleotide excision repair. Free Radic Biol Med. 2004 Apr 15;36(8):1011-7. [15059641 ]
  15. Eastwood MA, Brydon WG, Anderson DM: The effects of dietary gum karaya (Sterculia) in man. Toxicol Lett. 1983 Jun;17(1-2):159-66. [6623502 ]
  16. Supko JG, Malspeis L: Characterization of the urinary metabolites of merbarone in cancer patients. Drug Metab Dispos. 1991 Jan-Feb;19(1):263-73. [1673412 ]
  17. Escobar R, Cano Pavon JM: Selective spectrophotometric determination of trace amounts of iron with di(2-pyridyl)-NN-di[(8-quinolyl)amino]methane: determination of iron in blood serum. Analyst. 1983 Jul;108(1288):821-6. [6614500 ]
  18. Wolever TM, Fernandes J, Rao VA, Chiasson JL, Josse RG, Leiter LA: Positive methane-producing status associated with increased serum cholesterol in subjects with impaired glucose tolerance. Diabetes Care. 1995 Jul;18(7):1010-2. [7555532 ]
  19. Masson P, Marnot B, Lombard JY, Morelis P: [Electrophoretic study of aged butyrylcholinesterase after inhibition by soman]. Biochimie. 1984 Mar;66(3):235-49. [6331528 ]
  20. Sudaryanto A, Kunisue T, Tanabe S, Niida M, Hashim H: Persistent organochlorine compounds in human breast milk from mothers living in Penang and Kedah, Malaysia. Arch Environ Contam Toxicol. 2005 Oct;49(3):429-37. Epub 2005 Aug 24. [16132420 ]
  21. Nagao M, Takatori T, Oono T, Iwase H, Iwadate K, Yamada Y, Nakajima M: Death due to a methane gas explosion in a tunnel on urban reclaimed land. Am J Forensic Med Pathol. 1997 Jun;18(2):135-9. [9185928 ]
  22. Levitt MD, Furne JK, Kuskowski M, Ruddy J: Stability of human methanogenic flora over 35 years and a review of insights obtained from breath methane measurements. Clin Gastroenterol Hepatol. 2006 Feb;4(2):123-9. [16469670 ]
  23. Wikipedia. Methane. Last Updated 20 May 2009. [Link]
  24. Bacharach, Inc. (2004). Materials Safety Data Sheet (MSDS) for Methane. [Link]
  25. Matheson Tri-Gas, Inc. (2008). Materials Safety Data Sheet (MSDS) for Methane. [Link]
Gene Regulation
Up-Regulated GenesNot Available
Down-Regulated GenesNot Available