Carbon monoxide

aesthetics  →
being  →
complexity  →
database  →
enterprise  →
ethics  →
fiction  →
history  →
internet  →
knowledge  →
language  →
licensing  →
linux  →
logic  →
method  →
news  →
perception  →
philosophy  →
policy  →
purpose  →
religion  →
science  →
sociology  →
software  →
truth  →
unix  →
wiki  →
essay  →
feed  →
help  →
system  →
wiki  →
critical  →
discussion  →
forked  →
imported  →
original  →
Carbon monoxide
[ temporary import ]
please note:
- the content below is remote from Wikipedia
- it has been imported raw for GetWiki
{{for|the song by Cake|Carbon Monoxide (song)}}{{Chembox| verifiedrevid = 477004453| ImageFileL1 = Carbon-monoxide-3D-balls.png| ImageNameL1 = Ball-and-stick model of carbon monoxide| ImageFileR1 = Carbon-monoxide-3D-vdW.png| ImageNameR1 = Spacefill model of carbon monoxide| ImageFile2 = Carbon monoxide 2D.svg| ImageSize2 = 170px| ImageName2 = model of carbon monoxide| PIN = Carbon monoxide| OtherNames = Carbon monooxideCarbonous oxideCarbon(II) oxideCarbonylFlue gasMonoxide|Section1={{Chembox Identifiers| InChI = 1/CO/c1-2| InChIKey = UGFAIRIUMAVXCW-UHFFFAOYAT| CASNo = 630-08-0!Concentration!Source| 0.1 ppmv| 0.5–5 ppmv| 5–15 ppmv| Near-properly adjusted gas stoves in homes, modern vehicle exhaust emissionsWEB
, Gosink
, Tom
, What Do Carbon Monoxide Levels Mean?
, Alaska Science Forum
, Geophysical Institute, University of Alaska Fairbanks
, 1983-01-28
, 2007-12-01
,weblink" title="">weblink
, 2008-12-25
, dead
| 17 ppmv|Atmosphere of Venus| 100–200 ppmv| 700 ppmv|Atmosphere of Mars|

- content above as imported from Wikipedia
- "Carbon monoxide" does not exist on GetWiki (yet)
- time: 3:34am EDT - Tue, Oct 15 2019
[ this remote article is provided by Wikipedia ]
LATEST EDITS [ see all ]
Eastern Philosophy
History of Philosophy
M.R.M. Parrott
correct|CAS}}| PubChem = 281| ChemSpiderID = 275correct|chemspider}}correct|FDA}}| UNII = 7U1EE4V452| EINECS = 211-128-3| UNNumber = 1016correct|kegg}}| KEGG = D09706| MeSHName = Carbon+monoxidecorrect|EBI}}| ChEBI = 17245| RTECS = FG3500000| SMILES = [C-]#[O+]correct|chemspider}}| StdInChI = 1S/CO/c1-2correct|chemspider}}| StdInChIKey = UGFAIRIUMAVXCW-UHFFFAOYSA-N| Beilstein = 3587264| Gmelin = 421}}|Section2={{Chembox Properties| Formula = CO| MolarMass = 28.010 g/mol| Appearance = colorless gas| Odor = odorless| Density = 789 kg/m3, liquid1.250 kg/m3 at 0 Â°C, 1 atm1.145 kg/m3 at 25 Â°C, 1 atm| Solubility = 27.6 mg/L (25 Â°C)| SolubleOther = soluble in chloroform, acetic acid, ethyl acetate, ethanol, ammonium hydroxide, benzene| MeltingPtC = −205.02| BoilingPtC = −191.5Debye>D| RefractIndex = 1.0003364| HenryConstant = 1.04 atm·m3/mol| MagSus = −9.8·10−6 cm3/mol
}}|Section4={{Chembox Thermochemistry| HeatCapacity = 29.1 J/(K·mol)| Entropy = 197.7 J/(mol·K)| DeltaGf = | DeltaHf = −110.5 kJ/mol| DeltaHc = −283.4 kJ/mol
}}|Section7={{Chembox Hazards| ExternalSDS = ICSC 0023| EUClass = {{Hazchem F+}} {{Hazchem T+}}
TITLE=SITTIG'S HANDBOOK OF TOXIC AND HAZARDOUS CHEMICALS AND CARCINOGENSPUBLISHER=ELSEVIERPAGE=572URL=HTTPS://BOOKS.GOOGLE.COM/BOOKS?ID=F6HCLGOIKJCC&PG=PA572, 5 September 2015, | NFPA-H = 3| NFPA-F = 4| NFPA-R = 0| RPhrases = {{R61}} {{R12}} {{R26}} {{R48/23}}| SPhrases = {{S53}} {{S45}}| FlashPtC = −191| AutoignitionPtC = 609| ExploLimits = 12.5–74.2%0105}}| PEL = TWA 50 ppm (55 mg/m3)| REL = TWA 35 ppm (40 mg/m3) C 200 ppm (229 mg/m3)| IDLH = 1200 ppm630080|Carbon monoxide}}| LCLo = 4000 ppm (human, 30 min)5000 ppm (human, 5 min)
}}WEB,weblink CARBON MONOXIDE - CAMEO Chemicals - NOAA, NOAA Office of Response and Restoration, US, GOV,, |Section8={{Chembox Related| OtherFunction_label = carbon oxides| OtherFunction = Carbon dioxideCarbon suboxideOxocarbons
}}Carbon monoxide (CO) is a colorless, odorless, and tasteless flammable gas that is slightly less dense than air. It is toxic to animals that use hemoglobin as an oxygen carrier (both invertebrate and vertebrate) when encountered in concentrations above about 35 ppm, although it is also produced in normal animal metabolism in low quantities, and is thought to have some normal biological functions. In the atmosphere, it is spatially variable and short lived, having a role in the formation of ground-level ozone.
Carbon monoxide consists of one carbon atom and one oxygen atom, connected by a triple bond that consists of two covalent bonds as well as one dative covalent bond.WEB, Molecular orbitals in Carbon Monoxide CO, University of Liverpool,weblink May 10, 2016, It is the simplest oxocarbon and is isoelectronic with other triply-bonded diatomic molecules having ten valence electrons, including the cyanide anion, the nitrosonium cation and molecular nitrogen. In coordination complexes the carbon monoxide ligand is called carbonyl.


Aristotle (384–322 BC) first recorded that burning coals produced toxic fumes. An ancient method of execution was to shut the criminal in a bathing room with smoldering coals. What was not known was the mechanism of death. Greek physician Galen (129–199 AD) speculated that there was a change in the composition of the air that caused harm when inhaled.Penney, David G. (2000) Carbon Monoxide Toxicity, CRC Press, p. 5, {{ISBN|0-8493-2065-8}}. In 1776, the French chemist {{ill|de Lassone|fr|Joseph-Marie-François de Lassone}} produced CO by heating zinc oxide with coke, but mistakenly concluded that the gaseous product was hydrogen, as it burned with a blue flame. The gas was identified as a compound containing carbon and oxygen by the Scottish chemist William Cruikshank in 1800.Cruickshank, W. (1801) "Some observations on different hydrocarbonates and combinations of carbone with oxygen, etc. in reply to some of Dr. Priestley's late objections to the new system of chemistry," Journal of Natural Philosophy, Chemistry and the Arts [a.k.a. Nicholson's Journal], 1st series, 5 : 1–9.Cruickshank, W. (1801) "Some additional observations on hydrocarbonates, and the gaseous oxide of carbon," Journal of Natural Philosophy, Chemistry and the Arts, 1st series, 5 : 201–211. Its toxic properties on dogs were thoroughly investigated by Claude Bernard around 1846.BOOK,weblink 38, Molecules of death, Waring, Rosemary H., Steventon, Glyn B., Mitchell, Steve C., Imperial College Press, 2007, 978-1-86094-814-5, During World War II, a gas mixture including carbon monoxide was used to keep motor vehicles running in parts of the world where gasoline and diesel fuel were scarce. External (with a few exceptions) charcoal or wood gas generators were fitted, and the mixture of atmospheric nitrogen, hydrogen, carbon monoxide, and small amounts of other gases produced by gasification was piped to a gas mixer. The gas mixture produced by this process is known as wood gas. Carbon monoxide was also used on a large scale during the Holocaust at some Nazi German extermination camps, the most notable by gas vans in Chełmno, and in the Action T4 "euthanasia" program.BOOK,weblink 323, A history of modern Germany, 1800–2000, Kitchen, Martin, Wiley-Blackwell, 2006, 978-1-4051-0041-0,


Carbon monoxide is produced from the partial oxidation of carbon-containing compounds; it forms when there is not enough oxygen to produce carbon dioxide (CO2), such as when operating a stove or an internal combustion engine in an enclosed space. In the presence of oxygen, including atmospheric concentrations, carbon monoxide burns with a blue flame, producing carbon dioxide.Thompson, Mike. Carbon Monoxide – Molecule of the Month, Winchester College, UK. Coal gas, which was widely used before the 1960s for domestic lighting, cooking, and heating, had carbon monoxide as a significant fuel constituent. Some processes in modern technology, such as iron smelting, still produce carbon monoxide as a byproduct.BOOK,weblink 36, Crossing the Energy Divide: Moving from Fossil Fuel Dependence to a Clean-Energy Future, Ayres, Robert U., Ayres, Edward H., Wharton School Publishing, 2009, 978-0-13-701544-3, A large quantity of CO byproduct is formed during the oxidative processes for the production of chemicals. For this reason, the process off-gases have to be purified. On the other hand, considerable research efforts are made in order to optimize the process conditions,BOOK, Kinetic studies of propane oxidation on Mo and V based mixed oxide catalysts, 2011,weblink develop catalyst with improved selectivity JOURNAL, Multifunctionality of Crystalline MoV(TeNb) M1 Oxide Catalysts in Selective Oxidation of Propane and Benzyl Alcohol, ACS Catalysis, 26 April 2013, 3, 6, 1103–1113,weblink 10.1021/cs400010q, Amakawa, Kazuhiko, Kolen'Ko, Yury V., Villa, Alberto, Schuster, Manfred E/, Csepei, Lénárd-István, Weinberg, Gisela, Wrabetz, Sabine, Naumann d'Alnoncourt, Raoul, Girgsdies, Frank, Prati, Laura, Schlögl, Robert, Trunschke, Annette, and to understand the reaction pathways leading to the target product and side products.JOURNAL, The reaction network in propane oxidation over phase-pure MoVTeNb M1 oxide catalysts, Journal of Catalysis, March 2014, 311, 369–385,weblink 10.1016/j.jcat.2013.12.008, Naumann d'Alnoncourt, Raoul, Csepei, Lénárd-István, Hävecker, Michael, Girgsdies, Frank, Schuster, Manfred E., Schlögl, Robert, Trunschke, Annette, 2018-04-14,weblink" title="">weblink 2016-02-15, dead, JOURNAL, Surface chemistry of phase-pure M1 MoVTeNb oxide during operation in selective oxidation of propane to acrylic acid, Journal of Catalysis, January 2012, 285, 1, 48–60,weblink 10.1016/j.jcat.2011.09.012, Hävecker, Michael, Wrabetz, Sabine, Kröhnert, Jutta, Csepei, Lenard-Istvan, Naumann d'Alnoncourt, Raoul, Kolen'Ko, Yury V., Girgsdies, Frank, Schlögl, Robert, Trunschke, Annette, 2018-04-14,weblink" title="">weblink 2016-10-30, dead, Worldwide, the largest source of carbon monoxide is natural in origin, due to photochemical reactions in the troposphere that generate about 5{{e|12}} kilograms per year.JOURNAL, 10.1126/science.176.4032.290, Carbon Monoxide Balance in Nature, 1972, Weinstock, B., Niki, H., Science, 176, 290–2, 5019781, 4032, 1972Sci...176..290W, Other natural sources of CO include volcanoes, forest fires, other forms of combustion, and carbon monoxide-releasing molecules.In biology, carbon monoxide is naturally produced by the action of heme oxygenase 1 and 2 on the heme from hemoglobin breakdown. This process produces a certain amount of carboxyhemoglobin in normal persons, even if they do not breathe any carbon monoxide. Following the first report that carbon monoxide is a normal neurotransmitter in 1993,JOURNAL, 10.1126/science.7678352, Carbon monoxide: A putative neural messenger, 1993, Verma, A, Hirsch, D., Glatt, C., Ronnett, G., Snyder, S., Science, 259, 5093, 381–4, 7678352, 1993Sci...259..381V, NEWS, Carbon Monoxide Gas Is Used by Brain Cells As a Neurotransmitter, Gina, Kolata,weblink The New York Times, January 26, 1993, May 2, 2010, as well as one of three gases that naturally modulate inflammatory responses in the body (the other two being nitric oxide and hydrogen sulfide), carbon monoxide has received a great deal of clinical attention as a biological regulator. In many tissues, all three gases are known to act as anti-inflammatories, vasodilators, and promoters of neovascular growth.JOURNAL, 19486912, 2009, Li, L, Hsu, A, Moore, PK, Actions and interactions of nitric oxide, carbon monoxide and hydrogen sulphide in the cardiovascular system and in inflammation—a tale of three gases!, 123, 3, 386–400, 10.1016/j.pharmthera.2009.05.005, Pharmacology & Therapeutics, Clinical trials of small amounts of carbon monoxide as a drug are ongoing. Too much carbon monoxide causes carbon monoxide poisoning.

Molecular properties

Carbon monoxide has a molar mass of 28.0, which, according to the ideal gas law, makes it slightly less dense than air, whose average molar mass is 28.8.The bond length between the carbon atom and the oxygen atom is 112.8 pm.JOURNAL, Gilliam, O. R., Johnson, C. M., Gordy, W., Microwave Spectroscopy in the Region from Two to Three Millimeters, 1950, Physical Review, 78, 2, 140–144, 10.1103/PhysRev.78.140, 1950PhRv...78..140G, {{CRC91|page=9–33}} This bond length is consistent with a triple bond, as in molecular nitrogen (N2), which has a similar bond length (109.76 pm) and nearly the same molecular mass. Carbon–oxygen double bonds are significantly longer, 120.8 pm in formaldehyde, for example.{{CRC91|page=9–39}} The boiling point (82 K) and melting point (68 K) are very similar to those of N2 (77 K and 63 K, respectively). The bond-dissociation energy of 1072 kJ/mol is stronger than that of N2 (942 kJ/mol) and represents the strongest chemical bond known.Common Bond Energies (D) and Bond Lengths (r). wiredchemist.comThe ground electronic state of carbon monoxide is a singlet stateWEB, Highly Excited Triplet States of Carbon Monoxide, C. R., Vidal, 28 June 1997,weblinkweblink" title="">weblink 2006-08-28, August 16, 2012, since there are no unpaired electrons.

Bonding and dipole moment

The carbon monoxide has a very high bond-dissociation energy, the strongest of any neutral molecule, 11.65 eV. Carbon and oxygen together have a total of 10 electrons in the valence shell. Following the octet rule for both carbon and oxygen, the two atoms form a triple bond, with six shared electrons in three bonding molecular orbitals, rather than the usual double bond found in organic carbonyl compounds. Since four of the shared electrons come from the oxygen atom and only two from carbon, one bonding orbital is occupied by two electrons from oxygen, forming a dative or dipolar bond. This causes a C←O polarization of the molecule, with a small negative charge on carbon and a small positive charge on oxygen. The other two bonding orbitals are each occupied by one electron from carbon and one from oxygen, forming (polar) covalent bonds with a reverse C→O polarization, since oxygen is more electronegative than carbon. In the free carbon monoxide, a net negative charge δ– remains at the carbon end and the molecule has a small dipole moment of 0.122 D.JOURNAL, Scuseria, Gustavo E., Miller, Michael D., Jensen, Frank, Geertsen, Jan, The dipole moment of carbon monoxide, J. Chem. Phys., 94, 10, 6660, 1991, 10.1063/1.460293, 1991JChPh..94.6660S, The molecule is therefore asymmetric: oxygen has more electron density than carbon, and is also slightly positively charged compared to carbon being negative. By contrast, the isoelectronic dinitrogen molecule has no dipole moment.(File:Carbon Monoxide-2.png|thumb|The most important resonance form of carbon monoxide is C–≡O+. An important minor contributor is the non-octet carbenic structure :C=O.)Carbon monoxide has a computed fractional bond order of 2.6, indicating that the "third" bond is important but constitutes somewhat less than a full bond.JOURNAL, Martinie, Ryan J., Bultema, Jarred J., Vander Wal, Mark N., Burkhart, Brandon J., Vander Griend, Douglas A., DeKock, Roger L., 2011-08-01, Bond Order and Chemical Properties of BF, CO, and N2, Journal of Chemical Education, 88, 8, 1094–1097, 10.1021/ed100758t, 0021-9584, Thus, in valence bond terms, –C≡O+ is the most important structure, while :C=O is non-octet, but has a neutral formal charge on each atom and represents the second most important resonance contributor. Because of the lone pair and divalence of carbon in this resonance structure, carbon monoxide is often considered to be an extraordinarily stabilized carbene.BOOK, Cumulenes in click reactions, 1925-, Ulrich, Henri, 2009, Wiley, Wiley InterScience (Online service), 9780470747957, Chichester, U.K., 45, 476311784, Isocyanides are compounds in which the O is replaced by an NR (R = alkyl or aryl) group and have a similar bonding scheme.If carbon monoxide acts as a ligand, the polarity of the dipole may reverse with a net negative charge on the oxygen end, depending on the structure of the coordination complex.JOURNAL, Lupinetti, Anthony J., Fau, Stefan, Frenking, Gernot, Strauss, Steven H., Theoretical Analysis of the Bonding between CO and Positively Charged Atoms, J. Phys. Chem. A, 1997, 101, 49, 9551–9559, 10.1021/jp972657l, 1997JPCA..101.9551L, See also the section "Coordination chemistry" below.

Bond polarity and oxidation state

Theoretical and experimental studies show that, despite the greater electronegativity of oxygen, the dipole moment points from the more-negative carbon end to the more-positive oxygen end.JOURNAL, Blanco, Fernando, Alkorta, Ibon, Solimannejad, Mohammad, Elguero, Jose, Theoretical Study of the 1:1 Complexes between Carbon Monoxide and Hypohalous Acids, J. Phys. Chem. A, 2009, 113, 13, 19275137, 3237–3244, 10.1021/jp810462h, 2009JPCA..113.3237B, 10261/66300, JOURNAL, Meerts, W, Electric and magnetic properties of carbon monoxide by molecular-beam electric-resonance spectroscopy, Chemical Physics, 22, 2, 1 June 1977, 319–324, 10.1016/0301-0104(77)87016-X, 1977CP.....22..319M, De Leeuw, F.H., Dymanus, A., The three bonds are in fact polar covalent bonds that are strongly polarized. The calculated polarization toward the oxygen atom is 71% for the σ-bond and 77% for both π-bonds.JOURNAL, Stefan, Thorsten, Janoschek, Rudolf, How relevant are S=O and P=O Double Bonds for the Description of the Acid Molecules H2SO3, H2SO4, and H3PO3, respectively?, Journal of Molecular Modeling, 6, 2, 2000, 282–288, 10.1007/PL00010730, The oxidation state of carbon in carbon monoxide is +2 in each of these structures. It is calculated by counting all the bonding electrons as belonging to the more electronegative oxygen. Only the two non-bonding electrons on carbon are assigned to carbon. In this count, carbon then has only two valence electrons in the molecule compared to four in the free atom.

Biological and physiological properties


Carbon monoxide poisoning is the most common type of fatal air poisoning in many countries.JOURNAL, Omaye ST, Metabolic modulation of carbon monoxide toxicity, Toxicology, 2002, 139–150, 180, 2, 10.1016/S0300-483X(02)00387-6, 12324190, Carbon monoxide is colorless, odorless, and tasteless, but highly toxic. It combines with hemoglobin to produce carboxyhemoglobin, which usurps the space in hemoglobin that normally carries oxygen, but is ineffective for delivering oxygen to bodily tissues. Concentrations as low as 667 ppm may cause up to 50% of the body's hemoglobin to convert to carboxyhemoglobin.JOURNAL, 1592720, 1992, Tikuisis, P, Kane, DM, McLellan, TM, Buick, F, Fairburn, SM, Rate of formation of carboxyhemoglobin in exercising humans exposed to carbon monoxide, 72, 4, 1311–9, Journal of Applied Physiology, 10.1152/jappl.1992.72.4.1311, A level of 50% carboxyhemoglobin may result in seizure, coma, and fatality. In the United States, the OSHA limits long-term workplace exposure levels above 50 ppm.WEB, OSHA CO guidelines,weblink OSHA, May 27, 2009, dead,weblink January 26, 2010, The most common symptoms of carbon monoxide poisoning may resemble other types of poisonings and infections, including symptoms such as headache, nausea, vomiting, dizziness, fatigue, and a feeling of weakness. Affected families often believe they are victims of food poisoning. Infants may be irritable and feed poorly. Neurological signs include confusion, disorientation, visual disturbance, syncope (fainting), and seizures.Some descriptions of carbon monoxide poisoning include retinal hemorrhages, and an abnormal cherry-red blood hue.BOOK, Ganong, William F, Review of medical physiology,weblink May 27, 2009, 22, 2005, McGraw-Hill, 978-0-07-144040-0, 684, 37, In most clinical diagnoses these signs are seldom noticed.JOURNAL, Blumenthal, Ivan, 1 June 2001, Carbon monoxide poisoning, J R Soc Med, 94, 6, 270–272, 11387414, 1281520, 10.1177/014107680109400604, One difficulty with the usefulness of this cherry-red effect is that it corrects, or masks, what would otherwise be an unhealthy appearance, since the chief effect of removing deoxygenated hemoglobin is to make an asphyxiated person appear more normal, or a dead person appear more lifelike, similar to the effect of red colorants in embalming fluid. The "false" or unphysiologic red-coloring effect in anoxic CO-poisoned tissue is related to the meat-coloring commercial use of carbon monoxide, discussed below.Carbon monoxide also binds to other molecules such as myoglobin and mitochondrial cytochrome oxidase. Exposures to carbon monoxide may cause significant damage to the heart and central nervous system, especially to the globus pallidus,JOURNAL, Prockop LD, Chichkova RI, Carbon monoxide intoxication: an updated review, J Neurol Sci, 2007, 122–130, 262, 1–2, 17720201, 10.1016/j.jns.2007.06.037, often with long-term chronic pathological conditions. Carbon monoxide may have severe adverse effects on the fetus of a pregnant woman.BOOK,weblink 325, Maternal, fetal, & neonatal physiology: a clinical perspective, Tucker Blackburn, Susan, Elsevier Health Sciences, 2007, 978-1-4160-2944-1,

Normal human physiology

{{see also|Gaseous signaling molecules}}Carbon monoxide is produced naturally by the human body as a signaling molecule. Thus, carbon monoxide may have a physiological role in the body, such as a neurotransmitter or a blood vessel relaxant.JOURNAL, Wu, L, Carbon Monoxide: Endogenous Production, Physiological Functions, and Pharmacological Applications, Pharmacol Rev, 57, 4, 585–630, December 2005, 16382109, 10.1124/pr.57.4.3, Wang, R, Because of carbon monoxide's role in the body, abnormalities in its metabolism have been linked to a variety of diseases, including neurodegenerations, hypertension, heart failure, and pathological inflammation. Relative to inflammation, carbon monoxide has been shown to inhibit the movement of leukocytes to inflamed tissues, stimulate leukocyte phagocytosis of bacteria, and reduce the production of pro-inflammatory cytokines by leukocytes. In animal model studies, furthermore, carbon monoxide reduced the severity of experimentally induced bacterial sepsis, pancreatitis, hepatic ischemia/reperfusion injury, colitis, osteoarthritis, lung injury, lung transplantation rejection, and neuropathic pain while promoting skin wound healing. These actions are similar to those of Specialized pro-resolving mediators which act to dampen, reverse, and repair the tissue damage due to diverse inflammation responses. Indeed, carbon monoxide can act additively with one of these mediators (Resolvin D1) to limit inflammatory responses. The studies implicate carbon monoxide as a physiological contributor to limiting inflammation and suggest that its delivery by inhalation or carbon monoxide-forming drugs may be therapeutically useful for controlling pathological inflammatory responses.JOURNAL, Wallace JL, Ianaro A, Flannigan KL, Cirino G, Gaseous mediators in resolution of inflammation, Seminars in Immunology, 27, 3, 227–33, 2015, 26095908, 10.1016/j.smim.2015.05.004, JOURNAL, Uehara EU, Shida Bde S, de Brito CA, Role of nitric oxide in immune responses against viruses: beyond microbicidal activity, Inflammation Research, 64, 11, 845–52, 2015, 26208702, 10.1007/s00011-015-0857-2, JOURNAL, Nakahira K, Choi AM, Carbon monoxide in the treatment of sepsis, American Journal of Physiology. Lung Cellular and Molecular Physiology, 309, 12, L1387–93, 2015, 26498251, 10.1152/ajplung.00311.2015, 4683310, JOURNAL, Shinohara M, Serhan CN, Novel Endogenous Proresolving Molecules:Essential Fatty Acid-Derived and Gaseous Mediators in the Resolution of Inflammation, Journal of Atherosclerosis and Thrombosis, 23, 6, 655–64, 2016, 27052783, 10.5551/jat.33928,
CO functions as an endogenous signaling molecule, modulates functions of the cardiovascular system, inhibits blood platelet aggregation and adhesion, suppresses, reverses, and repairs the damage caused by inflammatory responses.It may play a role as potential therapeutic agent.JOURNAL, Olas, Beata, Carbon monoxide is not always a poison gas for human organism: Physiological and pharmacological features of CO, Chemico-Biological Interactions, 25 April 2014, 222, 5 October 2014, 37–43, 10.1016/j.cbi.2014.08.005, 25168849,


Carbon monoxide is a nutrient for methanogenic archaea, which reduce it to methane using hydrogen.JOURNAL, Thauer, R. K., Biochemistry of methanogenesis: a tribute to Marjory Stephenson. 1998 Marjory Stephenson Prize Lecture, 1998, Microbiology (journal), Microbiology, 144, 9, 2377–2406,weblink Free, 10.1099/00221287-144-9-2377, 9782487, This is the theme for the emerging field of bioorganometallic chemistry. Extremophile micro-organisms can, thus, utilize carbon monoxide in such locations as the thermal vents of volcanoes.Hogan, C. Michael (2010). "Extremophile" in E. Monosson and C. Cleveland (eds.). Encyclopedia of Earth. National Council for Science and the Environment, Washington, DCSome microbes can convert carbon monoxide to carbon dioxide to yield energy.JOURNAL, Martian life must be rare as free energy source remains untapped, New Scientist, May 13, 2017,weblink In bacteria, carbon monoxide is produced via the reduction of carbon dioxide by the enzyme carbon monoxide dehydrogenase, an Fe-Ni-S-containing protein.BOOK, Bioorganometallics: Biomolecules, Labeling, Medicine, Jaouen, G., Wiley-VCH, Weinheim, 2006, 978-3-527-30990-0, CooA is a carbon monoxide sensor protein.JOURNAL, Roberts, G. P., Youn, H., Kerby, R. L., CO-Sensing Mechanisms, Microbiology and Molecular Biology Reviews, 2004, 68, 453–473, 10.1128/MMBR.68.3.453-473.2004, 15353565, 3, 515253, The scope of its biological role is still unknown; it may be part of a signaling pathway in bacteria and archaea. Its occurrence in mammals is not established.


(File:MOP CO M.ogv|thumb|Monthly averages of global concentrations of tropospheric carbon monoxide at an altitude of about 12,000 feet. Data were collected by the MOPITT (Measurements Of Pollution In The Troposphere) sensor on NASA’s Terra satellite.Global Maps. Carbon Monoxide. monoxide occurs in various natural and artificial environments. Typical concentrations in parts per million are as follows:{| class="wikitable"
Composition of dry atmosphere, by volumeSource for figures: Carbon dioxide, NOAA Earth System Research Laboratory, (updated 2010.06). Methane, Intergovernmental Panel on Climate Change>IPCC TAR table 6.1, (updated to 1998). The NASA total was 17 ppmv over 100%, and CO2 was increased here by 15 ppmv. To normalize, N2 should be reduced by about 25 ppmv and O2 by about 7 ppmv.
ppmv: parts per million by volume (note: volume fraction is equal to mole fraction for ideal gas only, see volume (thermodynamics))