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Encyclopedia > Hydrogen sulfide
Hydrogen sulfide
IUPAC name Hydrogen sulfide, sulfane
Other names Sulfuretted hydrogen; sulfane; sulfur hydride; sour gas; sulfurated hydrogen; hydrosulfuric acid; sewer gas; stink damp
Identifiers
CAS number [7783-06-4]
RTECS number MX1225000
Properties
Molecular formula H2S
Molar mass 34.082 g/mol
Appearance Colorless gas.
Density 1.363 g/L, gas.
Melting point

-82.30 °C (190.85 K) Image File history File links Emblem-important. ... Image File history File links Hydrogen-sulfide-2D-dimensions. ... Image File history File links Download high-resolution version (1100x1092, 145 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Hydrogen sulfide User:Benjah-bmm27/Gallery User:Ben Mills/Gallery User:Benjah-bmm27/Gallery/Hydrogen ... IUPAC nomenclature is a system of naming chemical compounds and of describing the science of chemistry in general. ... CAS registry numbers are unique numerical identifiers for chemical compounds, polymers, biological sequences, mixtures and alloys. ... RTECS, also known as Registry of Toxic Effects of Chemical Substances, is a database of toxicity information compiled from the open scientific literature that is available for charge. ... A chemical formula is an easy way of expressing information about the atoms that constitute a particular chemical compound. ... Molar mass is the mass of one mole of a chemical element or chemical compound. ... For other uses, see Density (disambiguation). ... The melting point of a solid is the temperature range at which it changes state from solid to liquid. ...

Boiling point

-60.28 °C (212.87 K) Italic text This article is about the boiling point of liquids. ...

Solubility in water 0.25 g/100 mL (40 °C)
Acidity (pKa) 6.89
19±2 (See Text)
Structure
Molecular shape Bent
Dipole moment 0.97 D
Hazards
EU classification Corrosive(C)
Toxic (T)
Highly Flammable (F+)
R-phrases R12, R26, R50
S-phrases (S1/2), S9, S16
S36, S38, S45, S61
Flash point -82.4 °C
Related compounds
Related hydrogen compounds water; hydrogen selenide; hydrogen telluride
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox disclaimer and references

Hydrogen sulfide (or hydrogen sulphide) is the chemical compound with the formula H2S. This colorless, toxic and flammable gas is responsible for the foul odour of rotten eggs and flatulence. Solubility is a chemical property referring to the ability for a given substance, the solute, to dissolve in a solvent. ... Impact from a water drop causes an upward rebound jet surrounded by circular capillary waves. ... An acid dissociation constant, denoted by Ka, is an equilibrium constant for the dissociation of a weak acid. ... Four sp3 orbitals. ... The Earths magnetic field, which is approximately a dipole. ... The debye (symbol: D) is a non-SI and non-CGS unit of electrical dipole moment. ... Council Directive 67/548/EEC of 27 June 1967 on the approximation of laws, regulations and administrative provisions relating to the classification, packaging and labelling of dangerous substances (as amended) is the main European Union law concerning chemical safety. ... R-phrases are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous substances and preparations. ... S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. ... For other uses, see Flash point (disambiguation). ... H2O and HOH redirect here. ... Hydrogen selenide is H2Se, the simplest hydride of selenium. ... Hydrogen telluride is H2Te, the simplest hydride of tellurium. ... The plimsoll symbol as used in shipping In chemistry, the standard state of a material is its state at 1 bar (100 kilopascals exactly). ... Look up chemical compound in Wiktionary, the free dictionary. ... A chemical formula is an easy way of expressing information about the atoms that constitute a particular chemical compound. ... This article is about the chemistry of hydrogen. ... This article is about the chemical element. ... Toxic redirects here, but this is also the name of a song by Britney Spears; see Toxic (song) Look up toxic and toxicity in Wiktionary, the free dictionary. ... For other uses, see Gas (disambiguation). ... In most birds and reptiles, an egg (Latin ovum) is the zygote, resulting from fertilization of the ovum. ... Flatulence is the presence of a mixture of gases in the digestive tract of mammals. ...


It often results from the bacterial break down of organic matter in the absence of oxygen, such as in swamps and sewers (anaerobic digestion). It also occurs in volcanic gases, natural gas and some well waters. The odor of H2S is commonly misattributed to elemental sulfur, which is in fact odorless. Hydrogen sulfide has numerous names, some of which are archaic (see Table). Phyla Actinobacteria Aquificae Chlamydiae Bacteroidetes/Chlorobi Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Lentisphaerae Nitrospirae Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Verrucomicrobia Bacteria (singular: bacterium) are unicellular microorganisms. ... This article is about the chemical element and its most stable form, or dioxygen. ... This article does not cite any references or sources. ... Anaerobic digestion component of Lübeck mechanical biological treatment plant in Germany, 2007 Anaerobic digestion is a process in which microorganisms break down biodegradable material in the absence of oxygen. ... Cleveland Volcano in the Aleutian Islands of Alaska photographed from the International Space Station For other uses, see Volcano (disambiguation). ... For other uses, see Natural gas (disambiguation). ... This article is about the chemical element. ...

Contents

General properties

Hydrogen sulfide is a covalent hydride structurally related to water (H2O) since oxygen and sulfur occur in the same periodic table group. Covalent bonding is a form of chemical bonding characterized by the sharing of one or more pairs of electrons between atoms, in order to produce a mutual attraction, which holds the resultant molecule together. ... Hydride is the name given to the negative ion of hydrogen, H−. Although this ion does not exist except in extraordinary conditions, the term hydride is widely applied to describe compounds of hydrogen with other elements, particularly those of groups 1–16. ... Impact from a water drop causes an upward rebound jet surrounded by circular capillary waves. ... This article is about the chemical element and its most stable form, or dioxygen. ... This article is about the chemical element. ... A periodic table group is a vertical column in the periodic table of the chemical elements. ...


Hydrogen sulfide is weakly acidic, dissociating in aqueous solution into hydrogen cations H+ and the hydrosulfide anion HS: For alternative meanings see acid (disambiguation). ... A cation is an ion with positive charge. ... Bisulfide, also called hydrosulfide, refers the anion with the formula HS−, commonly written SH−. This species is the conjugate base of hydrogen sulfide: H2S HS− + H+ A variety of salts are known, including sodium hydrosulfide, potassium hydrosulfide, and ammonium hydrosulfide. ... An anion is an ion with negative charge. ...

H2S → HS + H+
Ka = 6.9×10−7 mol/L; pKa = 6.89.

The sulfide ion, S2−, is known in the solid state but not in aqueous solution (c.f. oxide). The second dissociation constant of hydrogen sulfide is often stated to be around 10−13, but it is now clear that this is an error caused by oxidation of the sulfur in alkaline solution. The current best estimate for pKa2 is 19±2.[1] An acid dissociation constant, denoted by Ka, is an equilibrium constant for the dissociation of a weak acid. ... Formally, sulfide is the dianion, S2−, which exists in strongly alkaline aqueous solutions formed from H2S or alkali metal salts such as Li2S, Na2S, and K2S. Sulfide is exceptionally basic and, with a pKa > 14, it does not exist in appreciable concentrations even in highly alkaline water. ... An oxide is a chemical compound containing at least one oxygen atom and other elements. ... An acid dissociation constant, denoted by Ka, is an equilibrium constant for the dissociation of a weak acid. ... The most fundamental reactions in chemistry are the redox processes. ...


Hydrogen sulfide reacts with many metals cations to produce the corresponding metal sulfides. Well-known examples are silver sulfide (Ag2S), the tarnish that forms on silver when exposed to the hydrogen sulfide of the atmosphere, and cadmium sulfide (CdS), a pigment also known as cadmium yellow. Transition metal sulfides are characteristically insoluble, thus H2S is commonly used to separate metal ions from aqueous solutions. (Sulfides should not be confused with sulfites or sulfates, which contain the sulfite ion SO32− and the sulfate ion SO42−, respectively.) This article is about metallic materials. ... Formally, sulfide is the dianion, S2−, which exists in strongly alkaline aqueous solutions formed from H2S or alkali metal salts such as Li2S, Na2S, and K2S. Sulfide is exceptionally basic and, with a pKa > 14, it does not exist in appreciable concentrations even in highly alkaline water. ... Silver sulfide (or Silver sulphide in British English) is a black compound of silver. ... Tarnish is a layer of corrosion that develops over copper, brass, silver, aluminum as well as a degree of semi-reactive metals as they undergo oxidation. ... This article is about the chemical element. ... Cadmium sulfide (UK English sulphide), the mineral greenockite, is an hexagonal, yellowish crystal with specific gravity of 4. ... Natural Ultramarine pigment in powdered form. ... In chemistry, the term transition metal (sometimes also called a transition element) has two possible meanings: It commonly refers to any element in the d-block of the periodic table, including zinc, cadmium and mercury. ... Formally, sulfide is the dianion, S2−, which exists in strongly alkaline aqueous solutions formed from H2S or alkali metal salts such as Li2S, Na2S, and K2S. Sulfide is exceptionally basic and, with a pKa > 14, it does not exist in appreciable concentrations even in highly alkaline water. ... Sulfites (also sulphite) are compounds that contain the sulfite ion SO32−. They are often used as preservatives in wines (to prevent spoilage and oxidation), dried fruits, and dried potato products. ... The sulfate anion, SO42− The structure and bonding of the sulfate ion In inorganic chemistry, a sulfate (IUPAC-recommended spelling; also sulphate in British English) is a salt of sulfuric acid. ...


Hydrogen sulfide is corrosive and renders some steels brittle, leading to sulfide stress cracking — a concern especially for handling "sour gas" and sour crude oil in the oil industry. Hydrogen sulfide burns to give the gas sulfur dioxide, which is more familiar as the odor of a burnt match. For the hazard, see corrosive. ... For other uses, see Steel (disambiguation). ... Sulphide stress cracking (SSC), or sulphide stress corrosion cracking (SSCC), is a special corrosion type, a form of stress corrosion cracking. ... Sour gas is natural gas or any other gas containing significant amounts of hydrogen sulfide (H2S). ... Sour crude oil contains the impurities hydrogen sulfide (H2S) and carbon dioxide,or mercaptans. ... The Oil industry brings to market what is currently considered the lifeblood of nearly all other industry, if not industrialized civilization itself. ... Sulfur dioxide (or Sulphur dioxide) has the chemical formula SO2. ...


Occurrence

Deposit of sulfur on a rock, caused by volcanic gases
Deposit of sulfur on a rock, caused by volcanic gases

Small amounts of hydrogen sulfide occur in crude petroleum but natural gas can contain up to 90%. Volcanoes and hot springs emit some H2S, where it probably arises via the hydrolysis of sulfide minerals, i.e. MS + H2O → MO + H2S. Normal concentration in clean air is about 0.0001-0.0002 ppm.[citation needed] Image File history File linksMetadata Download high-resolution version (1280x960, 599 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Hydrogen sulfide Metadata This file contains additional information, probably added from the digital camera or scanner used to... Image File history File linksMetadata Download high-resolution version (1280x960, 599 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Hydrogen sulfide Metadata This file contains additional information, probably added from the digital camera or scanner used to... Nodding donkey pumping an oil well near Sarnia, Ontario, 2001 Petroleum (from Latin petrus – rock and oleum – oil), mineral oil, or crude oil, sometimes colloquially called black gold, is a thick, dark brown or greenish flammable liquid, which exists in the upper strata of some areas of the Earths... For other uses, see Natural gas (disambiguation). ... Cleveland Volcano in the Aleutian Islands of Alaska photographed from the International Space Station For other uses, see Volcano (disambiguation). ... Green Dragon Spring at Norris Geyser A hot spring is a place where warm or hot groundwater issues from the ground on a regular basis for at least a predictable part of the year, and is significantly above the ambient ground temperature (which is usually around 55~57 F or... Hydrolysis is a chemical reaction or process in which a chemical compound is broken down by reaction with water. ... Parts per million (ppm) is a measure of concentration that is used where low levels of concentration are significant. ...


Sulfate-reducing bacteria obtain energy by oxidizing organic matter or hydrogen with sulfates, producing H2S. These microorganisms are prevalent in low-oxygen environments, such as in swamps and standing waters. Sulfur-reducing bacteria (such as Salmonella) and some archaea obtain their energy by oxidizing organic matter or hydrogen with elemental sulfur, also producing H2S. Other anaerobic bacteria liberate hydrogen sulfide when they digest sulfur-containing amino acids, for instance during the decay of organic matter. H2S-producing bacteria also operate in the human colon, and the odor of flatulence is largely due to trace amounts of the gas. Such bacterial action in the mouth may contribute to bad breath. Evidence exists that hydrogen sulfide produced by sulfate-reducing bacteria in the colon may cause or contribute to ulcerative colitis. Sulfate-reducing bacteria comprise several groups of bacteria that use sulfate as an oxidizing agent, reducing it to sulfide. ... ed|other uses|reduction}} Illustration of a redox reaction Redox (shorthand for reduction/oxidation reaction) describes all chemical reactions in which atoms have their oxidation number (oxidation state) changed. ... The sulfate anion, SO42− The structure and bonding of the sulfate ion In inorganic chemistry, a sulfate (IUPAC-recommended spelling; also sulphate in British English) is a salt of sulfuric acid. ... Sulfur-reducing bacteria specialize in producing energy by reducing elemental sulfur to hydrogen sulfide with hydrogen or organic compounds. ... Species S. enterica This article is about the bacteria. ... Phyla Crenarchaeota Euryarchaeota Korarchaeota Nanoarchaeota ARMAN The Archaea (pronounced ) are a group of prokaryotic and single-celled microorganisms. ... This article is about the chemical element. ... Aerobic and anaerobic bacteria can be identified by growning them in liquid culture: 1: Obligate aerobic bacteria gather at the top of the test tube in order to absorb maximal amount of oxygen. ... This article is about the class of chemicals. ... It has been suggested that this article or section be merged with Large intestine. ... Flatulence is the presence of a mixture of gases in the digestive tract of mammals. ... Halitosis, breath odour, or most commonly bad breath are terms used to describe noticeably unpleasant odours exhaled in breathing. ...


About 10% of total global emissions of H2S are due to human activity. By far the largest industrial route to H2S occurs in petroleum refineries: the hydrodesulfurization process liberates sulfur from petroleum by the action of hydrogen. The resulting H2S is converted to elemental sulfur by partial combustion via the Claus process, which is a major source of elemental sulfur. Other anthropogenic sources of hydrogen sulfide include coke ovens, paper mills (using the sulfate method), and tanneries. H2S arises from virtually anywhere where elemental sulfur comes into contact with organic material, especially at high temperatures. View of Shell Oil Refinery in Martinez, California. ... Hydrodesulfurization is one means of lowering the sulfur content of liquids from oil/coal. ... Petro redirects here. ... This article needs to be cleaned up to conform to a higher standard of quality. ... Coke Coke is a solid carbonaceous material derived from destructive distillation of low-ash, low-sulfur bituminous coal. ... International Paper Companys Kraft paper mill in Georgetown, South Carolina. ... This article is about making hides into leather. ...


Hydrogen sulfide can be present naturally in well water. In such cases, ozone is often used for its removal. An alternative method uses a filter with manganese dioxide. Both methods oxidize sulfides to less toxic sulfates. For other uses, see Ozone (disambiguation). ... Manganese(IV) oxide is the chemical compound MnO2, commonly called manganese dioxide. ... The sulfate anion, SO42− The structure and bonding of the sulfate ion In inorganic chemistry, a sulfate (IUPAC-recommended spelling; also sulphate in British English) is a salt of sulfuric acid. ...


A buildup of hydrogen sulfide in the atmosphere could have caused the Permian-Triassic extinction event 252 million years ago.[2] The Permian-Triassic (P-T or PT) extinction event, sometimes informally called the Great Dying, was an extinction event that occurred approximately 251 million years ago (mya), forming the boundary between the Permian and Triassic geologic periods. ...


Uses

Production of thioorganic compounds

Several organosulfur compounds are produced using hydrogen sulfide. These include methanethiol, ethanethiol, and thioglycolic acid. Organosulfur compounds are organic compounds containing sulfur. ... Methanethiol (also known as methyl mercaptan) is a colorless gas with a smell like rotten cabbage. ... Ethanethiol, also known as ethyl mercaptan, is an organic compound used as an odorant in propane. ... Thioglycolic acid (TGA) is the organic compound HSCH2CO2H. It contains both a thiol (mercaptan) and a carboxylic acid. ...


Alkali metal sulfides

Upon combining with alkali metal bases, hydrogen sulfide converts to alkali hydrosulfides such as sodium hydrosulfide and sodium sulfide, which are used in the degradation of biopolymers. The depilation of hides and the delignification of pulp by the Kraft process both are effected by alkali sulfides. Sodium hydrosulfide is the chemical compound with the formula NaSH. Other names include sodium bisulfide, sodium sulfhydrate, and sodium hydrogen sulfide. ... Sodium sulfide, or Na2S, is a water soluble chemical compound. ... Depilation is a generic term for hair removal which affects the part of the hair above the surface of the skin. ... The Kraft process (also known as Kraft pulping or sulfate process) is used in production of paper pulp and involves the use of caustic sodium hydroxide and sodium sulfide to extract the lignin from wood chips in large pressure vessels called digesters. ...


In analytical chemistry

Hydrogen sulfide used to have importance in analytical chemistry for well over a century, in the qualitative inorganic analysis of metal ions. For such small-scale laboratory use, H2S was made as needed in a Kipp generator by reaction of sulfuric acid (H2SO4) with ferrous sulfide FeS. Kipp generators were superseded by the use of thioacetamide, an organic solid that converts in water to H2S. In these analyses, heavy metal (and nonmetal) ions (e.g. Pb(II), Cu(II), Hg(II), As(III)) are precipitated from solution upon exposure to H2S. The components of the resulting precipitate redissolve with some selectivity. This article does not cite any references or sources. ... Classical qualitative inorganic analysis is a method of analytical chemistry which seeks to find elemental composition of inorganic compounds. ... Kipps apparatus, also called Kipp generator, is an apparatus used in chemical laboratories for preparation of small volumes of gases. ... Sulfuric acid, (also known as sulphuric acid) H2SO4, is a strong mineral acid. ... Iron(II) sulfide is a form of iron sulfide (others include iron pyrite a. ... Structural formula of thioacetamide Thioacetamide is an organic compound (formula CH3CSNH2, CAS: 62-55-5)), that appears as a white crystal under standard conditions. ... Together with the metals and metalloids, a nonmetal is one of three categories of chemical elements as distinguished by ionization and bonding properties. ...


A precursor to metal sulfides

As indicated above, many metal ions react with hydrogen sulfide to give the corresponding metal sulfides. This conversion is widely exploited. In the purification of metal ores by flotation, mineral powders are often treated with hydrogen sulfide to enhance the separation. Metal parts are sometimes passivated with hydrogen sulfide. Catalysts used in hydrodesulfurization are routinely activated with hydrogen sulfide, and the behavior of metallic catalysts used in other parts of a refinery is also modified using hydrogen sulfide. Flotation is a method for the separation of mixtures. ... Hydrodesulfurization is one means of lowering the sulfur content of liquids from oil/coal. ... A refinery is composed of a group of chemical engineering unit processes and unit operations used for refining certain materials or converting raw material into products of value. ...


Suicide

Hydrogen Sulfide has been used frequently in Japan, created when mixing a detergent with a shampoo. Inhalation of the compound is lethal. The Japanese government have been battling an alarming surge in suicides using this method.


Miscellaneous applications

Hydrogen sulfide is also used in the separation of deuterium oxide, i.e. heavy water, from normal water via the Girdler Sulfide process. Heavy water is dideuterium oxide, or D2O or 2H2O. It is chemically the same as normal water, H2O, but the hydrogen atoms are of the heavy isotope deuterium, in which the nucleus contains a neutron in addition to the proton found in the nucleus of any hydrogen atom. ... The Girdler Sulfide process is an industrial production method for making heavy water (dideuterium oxide), an important component of many nuclear reactors because it acts as a neutron moderator. ...


Safety

Hydrogen sulfide is a highly toxic and flammable gas. Being heavier than air, it tends to accumulate at the bottom of poorly ventilated spaces. Although very pungent at first, it quickly deadens the sense of smell, so potential victims may be unaware of its presence until it is too late. For more information see an MSDS. Toxic redirects here, but this is also the name of a song by Britney Spears; see Toxic (song) Look up toxic and toxicity in Wiktionary, the free dictionary. ... This page meets Wikipedias criteria for speedy deletion. ...


In Japan in early 2008, several people either attempted or succeeded in committing suicide using "homemade" hydrogen sulfide, in some cases sickening others in the immediate surroundings.[3][4]


Toxicity

Hydrogen sulfide is considered a broad-spectrum poison, meaning that it can poison several different systems in the body, although the nervous system is most affected. The toxicity of H2S is comparable with that of hydrogen cyanide. It forms a complex bond with iron in the mitochondrial cytochrome enzymes, thereby blocking oxygen from binding and stopping cellular respiration. Since hydrogen sulfide occurs naturally in the environment and the gut, enzymes exist in the body capable of detoxifying it by oxidation to (harmless) sulfate.[5] Hence low levels of sulfide may be tolerated indefinitely. However, at some threshold level, the oxidative enzymes will be overwhelmed. This threshold level is believed to average around 300-350 ppm. Many personal safety gas detectors are set to alarm at as low as 5 PPM to 10 PPM and to go into high alarm at 15 PPM (Utility, sewage & petrochemical workers). The nervous system is a highly specialized network whose principal components are nerves called neurons. ... R-phrases , , , , . S-phrases , , , , , , , , . Flash point −17. ... General Name, symbol, number iron, Fe, 26 Chemical series transition metals Group, period, block 8, 4, d Appearance lustrous metallic with a grayish tinge Standard atomic weight 55. ... In cell biology, a mitochondrion is an organelle found in the cells of most eukaryotes. ... Cytochromes are generally membrane-bound proteins that contain heme groups and carry out electron transport or catalyse reductive/oxidative reactions. ... Ribbon diagram of the enzyme TIM, surrounded by the space-filling model of the protein. ... Cellular respiration was discovered by mad scientist Mr. ...


An interesting diagnostic clue of extreme poisoning by H2S is the discoloration of copper coins in the pockets of the victim. Treatment involves immediate inhalation of amyl nitrite, injections of sodium nitrite, inhalation of pure oxygen, administration of bronchodilators to overcome eventual bronchospasm, and in some cases hyperbaric oxygen therapy. For other uses, see Copper (disambiguation). ... Amyl nitrite is the chemical compound with the formula C5H11ONO. A variety of isomers are known, but they all feature an amyl group attached to the nitrito functional group. ... Sodium nitrite, with chemical formula NaNO2, is used as a color fixative and preservative in meats and fish. ... A bronchodilator is a medication intended to improve bronchial airflow. ... Bronchospasm is a difficulty in breathing caused by a sudden constriction of the muscles in the walls of the bronchioles. ...


Exposure to lower concentrations can result in eye irritation, a sore throat and cough, nausea, shortness of breath, and fluid in the lungs. These symptoms usually go away in a few weeks. Long-term, low-level exposure may result in fatigue, loss of appetite, headaches, irritability, poor memory, and dizziness. Chronic exposures to low level H2S (around 2 ppm) has been implicated in increased miscarriage and reproductive health issues amongst Russian and Finnish wood pulp workers, but the reports hadn't (as of circa 1995) been replicated. Higher concentrations of 700-800 ppm tend to be fatal. For other uses, see Eye (disambiguation). ... For the village in Tibet, see Lung, Tibet. ... The word fatigue is used in everyday living to describe a range of afflictions, varying from a general state of lethargy to a specific work induced burning sensation within muscle. ... A headache is a condition of mild to severe pain in the head; sometimes upper back or neck pain may also be interpreted as a headache. ... Many different terms are often used to describe what is collectively known as dizziness. ... Parts per million (ppm) is a measure of concentration that is used where low levels of concentration are significant. ... Parts per million (ppm) is a measure of concentration that is used where low levels of concentration are significant. ...

  • 0.0047 ppm is the recognition threshold, the concentration at which 50% of humans can detect the characteristic odor of hydrogen sulfide [3], normally described as resembling "a rotten egg".
  • 10-20 ppm is the borderline concentration for eye irritation.
  • 50-100 ppm leads to eye damage.
  • At 150-250 ppm the olfactory nerve is paralyzed after a few inhalations, and the sense of smell disappears, often together with awareness of danger,
  • 320-530 ppm leads to pulmonary edema with the possibility of death.
  • 530-1000 ppm causes strong stimulation of the central nervous system and rapid breathing, leading to loss of breathing;
    • 800 ppm is the lethal concentration for 50% of humans for 5 minutes exposure(LC50).
  • Concentrations over 1000 ppm cause immediate collapse with loss of breathing, even after inhalation of a single breath.

A practical test used in the oilfield industry to determine whether someone requires overnight observation for pulmonary edema is the knee test: if a worker that gets "gassed" loses his balance and at least one knee touches the ground, the dose was high enough to cause pulmonary edema. Pulmonary edema is swelling and/or fluid accumulation in the lungs. ... A diagram showing the CNS: 1. ... In toxicology, the LD50 or colloquially semilethal dose of a particular substance is a measure of how much constitutes a lethal dose. ... Pulmonary edema is swelling and/or fluid accumulation in the lungs. ...


Function in the body

Hydrogen sulfide is produced in small amounts by some cells of the mammalian body and has a number of biological functions. (nitric oxide (NO) and carbon monoxide (CO) are also implicated as gaseous signalling agents.) It is produced from cysteine by various enzymes. It acts as a vasodilator and is also active in the brain, where it increases the response of the NMDA receptor and facilitates long term potentiation, which is involved in the formation of memory. Eventually the gas is converted to sulfites and further oxidized to thiosulfate and sulfate.[citation needed] Due to its effects similar to NO (without it's potential to form peroxides by interacting with superoxide), hydrogen sulfide is now recognized as a potential cardioprotective agent.[6] Vasoactivity of garlic is caused by catabolism of its polysulfides to H2S, a reaction which could depend on reduction mediated by glutathione.[7] In trisomy 21 (the most common form of Down syndrome) the body produces an excess of hydrogen sulfide. Subclasses & Infraclasses Subclass †Allotheria* Subclass Prototheria Subclass Theria Infraclass †Trituberculata Infraclass Metatheria Infraclass Eutheria For the folk-rock band see The Mammals. ... R-phrases , , , , S-phrases , , , Except where noted otherwise, data are given for materials in their standard state (at 25 Â°C, 100 kPa) Infobox disclaimer and references Nitric oxide or Nitrogen monoxide is a chemical compound with chemical formula NO. This gas is an important signaling molecule in the body of... Carbon monoxide, with the chemical formula CO, is a colorless, odorless, and tasteless gas. ... Cysteine is a naturally occurring, sulfur-containing amino acid that is found in most proteins, although only in small quantities. ... Ribbon diagram of the enzyme TIM, surrounded by the space-filling model of the protein. ... A vasodilator is a drug or chemical that relaxes the smooth muscle in blood vessels, which causes them to dilate. ... For other uses, see Brain (disambiguation). ... The NMDA receptor (NMDAR) is an ionotropic receptor for glutamate (NMDA (N-methyl d-aspartate) is a name of its selective specific agonist). ... In neuroscience, long-term potentiation (LTP) is the strengthening (or potentiation) of the connection between two nerve cells which lasts for an extended period of time (minutes to hours in vitro and hours to days and months in vivo). ... Sulfites (also sulphite) are compounds that contain the sulfite ion SO32−. They are often used as preservatives in wines (to prevent spoilage and oxidation), dried fruits, and dried potato products. ... It has been suggested that thiosulfate ion be merged into this article or section. ... The sulfate anion, SO42− The structure and bonding of the sulfate ion In inorganic chemistry, a sulfate (IUPAC-recommended spelling; also sulphate in British English) is a salt of sulfuric acid. ... Peroxide has three distinct meanings: Colloquial meaning In common usage, peroxide is an aqueous solution of hydrogen peroxide (HOOH or H2O2) sold for use as a disinfectant or mild bleach. ... Lewis electron configuration of superoxide. ... Binomial name L. Allium sativum L., commonly known as garlic, is a species in the onion family Alliaceae. ... Anabolism is the aspect of metabolism that contributes to growth. ... Allicin is a powerful antibiotic and anti-fungal compound obtained from garlic. ... Glutathione (GSH) is a tripeptide. ... A child with Down syndrome Down syndrome (also called Downs syndrome) encompasses a number of genetic disorders, of which trisomy 21 (a nondisjunction) is the most representative, causing highly variable degrees of learning difficulties and physical disabilities. ...


Induced hibernation

In 2005 it was shown that mice can be put into a state of suspended animation-like hypothermia by applying a low dosage of hydrogen sulfide (80 ppm H2S) in the air. The breathing rate of the animals sank from 120 to 10 breaths per minute and their temperature fell from 37 °C to just 2 °C above ambient temperature (in effect, they had become cold-blooded). The mice survived this procedure for 6 hours and afterwards showed no negative health consequences.[8] In 2006 it was shown that the blood pressure of mice treated in this fashion with hydrogen sulfide did not significantly decrease.[9] Binomial name Mus musculus Linnaeus, 1758 Mus musculus is the common house mouse. ... This article is about suspended animation in a medical context. ... Hypothermia is a condition in which an organisms temperature drops below that Required fOr normal metabolism and Bodily functionS. In warm-blooded animals, core [[body Temperature]] is maintained nEar a constant leVel through biologic [[homEostasis]]. But wheN the body iS exposed to cold Its internal mechanismS may be unable... Parts per million (ppm) is a measure of concentration that is used where low levels of concentration are significant. ... This article needs to be cleaned up to conform to a higher standard of quality. ... A sphygmomanometer, a device used for measuring arterial pressure. ...


Such a hibernation occurs naturally in many mammals and also in toads, but not in mice. (Mice can fall into a state called clinical torpor when food shortage occurs). If the H2S-induced hibernation can be made to work in humans, it could be useful in the emergency management of severely injured patients, and in the conservation of donated organs. This article refers to the process of hibernation in biology. ... Subclasses & Infraclasses Subclass †Allotheria* Subclass Prototheria Subclass Theria Infraclass †Trituberculata Infraclass Metatheria Infraclass Eutheria For the folk-rock band see The Mammals. ... For other uses, see Toad (disambiguation). ... Torpor is a state of regulated hypothermia in an endotherm lasting for periods ranging from just a few hours to several months. ...


As mentioned above, hydrogen sulfide binds to cytochrome oxidase and thereby prevents oxygen from binding, which leads to the dramatic slowdown of metabolism. Animals and humans naturally produce some hydrogen sulfide in their body; researchers have proposed that the gas is used to regulate metabolic activity and body temperature, which would explain the above findings.[10] Cytochrome c oxidase The enzyme cytochrome c oxidase (PDB 2OCC, EC 1. ... Structure of the coenzyme adenosine triphosphate, a central intermediate in energy metabolism. ...


However, a 2008 study failed to reproduce the effect in pigs, concluding that the effects seen in mice were not present in larger mammals.[11]


Participant in the sulfur cycle

Hydrogen sulfide is a central participant in the sulfur cycle, the biogeochemical cycle of sulfur on Earth. As mentioned above, sulfur-reducing and sulfate-reducing bacteria derive energy from oxidizing hydrogen or organic molecules in the absence of oxygen by reducing sulfur or sulfate to hydrogen sulfide. Other bacteria liberate hydrogen sulfide from sulfur-containing amino acids. Several groups of bacteria can use hydrogen sulfide as fuel, oxidizing it to elemental sulfur or to sulfate by using dissolved oxygen, metal oxides (e.g. Fe oxyhyroxides and Mn oxides) or nitrate as oxidant[12]. The purple sulfur bacteria and the green sulfur bacteria use hydrogen sulfide as electron donor in photosynthesis, thereby producing elemental sulfur. (In fact, this mode of photosynthesis is older than the mode of cyanobacteria, algae and plants which uses water as electron donor and liberates oxygen.) Wikipedia does not have an article with this exact name. ... In ecology, a biogeochemical cycle is a circuit where a nutrient moves back and forth between both biotic and abiotic components of ecosystems. ... This article is about the chemical element. ... ed|other uses|reduction}} Illustration of a redox reaction Redox (shorthand for reduction/oxidation reaction) describes all chemical reactions in which atoms have their oxidation number (oxidation state) changed. ... This article is about the class of chemicals. ... ed|other uses|reduction}} Illustration of a redox reaction Redox (shorthand for reduction/oxidation reaction) describes all chemical reactions in which atoms have their oxidation number (oxidation state) changed. ... Families Chromatiaceae Ectothiorhodospiraceae Halothiobacillaceae The purple sulfur bacteria are a group of Proteobacteria capable of photosynthesis, collectively referred to as purple bacteria. ... Green sulfur bacteria - Wikipedia, the free encyclopedia /**/ @import /skins-1. ... Photosynthesis splits water to liberate O2 and fixes CO2 into sugar The leaf is the primary site of photosynthesis in plants. ... Orders The taxonomy is currently under revision. ... Osborne (talk) 20:17, 5 December 2007 (UTC):For the programming language, see algae (programming language) Laurencia, a marine red alga from Hawaii. ... For other uses, see Plant (disambiguation). ...


H2S implicated in mass extinctions

Hydrogen sulfide has been implicated in some of the five mass extinctions that have occurred in the Earth's past. Although asteroid impacts are thought to have caused some extinctions, the Permian mass extinction (sometimes known as the "Great Dying") may have been caused by hydrogen sulfide. Organic residues from these extinction boundaries indicate that the oceans were anoxic (oxygen depleted) and had species of shallow plankton that metabolized H2S. The formation of H2S may have been initiated by massive volcanic eruptions, which emitted CO2 and methane into the atmosphere which warmed the oceans, lowering their capacity to absorb oxygen which would otherwise oxidize H2S. The increased levels of hydrogen sulfide could have killed oxygen-generating plants as well as depleted the ozone layer causing further stress. Small H2S blooms have been detected in modern times in the Dead Sea and in the Atlantic ocean off the coast of Namibia.[2] The Permian-Triassic extinction event, sometimes informally called the Great Dying, was an extinction event that occurred approximately 252 million years ago (mya), forming the boundary of the Permian and Triassic geologic periods. ... The Dead Sea (Hebrew: ‎, , Sea of Salt; Arabic: , , Dead Sea) is a salt lake between the West Bank and Israel to the west, and Jordan to the east. ...


See also

Amine gas treating is a means to remove organosulfur and other undesirable compounds from acid gas by contacting the gas with amine. ... This article needs to be cleaned up to conform to a higher standard of quality. ... Hypothermia being induced by using water circulated through heat-conducting pads Induced hypothermia (also known as therapeutic hypothermia) is the intentional induction of hypothermia for medical purposes. ...

References

  1. ^ Giggenbach, W. (1971). Inorg. Chem. 10:1333. Meyer, B.; Ward, K.; Koshlap, K.; & Peter, L. (1983). Inorganic Chemistry 22:2345. Myers, R. J. (1986). Journal of Chemical Education 63:687.
  2. ^ a b "Impact From the Deep" in the October 2006 issue of Scientific American.
  3. ^ [1]Number of suicides using detergent surges in Japan, alarms officials
  4. ^ [2] Hydrogen sulfide suicides putting family, neighbors at risk
  5. ^ S. Ramasamy, S. Singh, P. Taniere, M. J. S. Langman, M. C. Eggo (2006). "Sulfide-detoxifying enzymes in the human colon are decreased in cancer and upregulated in differentiation". Am J Physiol Gastrointest Liver Physiol 291: G288-G296. Retrieved on 2007-10-20. 
  6. ^ A new gaseous signaling molecule emerges: Cardioprotective role of hydrogen sulfide. Since H2S is not "new", the term most likely refers to commentator's prior subjective unawareness.
  7. ^ Hydrogen sulfide mediates the vasoactivity of garlic.
  8. ^ Mice put in 'suspended animation', BBC News, 21 April 2005
  9. ^ Gas induces 'suspended animation', BBC News, 9 October 2006
  10. ^ Mark B. Roth and Todd Nystul. Buying Time in Suspended Animation. Scientific American, 1 June 2005
  11. ^ Li, Jia; Zhang, Gencheng; Cai, Sally; Redington, Andrew N (January 2008). "Effect of inhaled hydrogen sulfide on metabolic responses in anesthetized, paralyzed, and mechanically ventilated piglets.". Pediatric Critical Care Medicine 9 (1): 110-112. Retrieved on 2008-02-07. “H2S does not appear to have hypometabolic effects in ambiently cooled large mammals and conversely appears to act as a hemodynamic and metabolic stimulant.” 
  12. ^ Jørgensen, B. B. & D. C. Nelson (2004) Sulfide oxidation in marine sediments: Geochemistry meets microbiology, pp. 36-81. In J. P. Amend, K. J. Edwards, and T. W. Lyons (eds.) Sulfur Biogeochemistry - Past and Present. Geological Society of America.
  • "Hydrogen Sulfide", Committee on Medical and Biological Effects of Environmental Pollutants, University Park Press, 1979, Baltimore. ISBN 0-8391-0127-9
  • "Girl's suicide leaves dozens ill from fumes", http://edition.cnn.com/2008/WORLD/asiapcf/04/24/detergent.suicide.ap/index.html?iref=mpstoryview
  • "Number of suicides using detergent surges in Japan, alarms officials", http://mdn.mainichi.jp/national/news/20080426p2a00m0na002000c.html

Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 293rd day of the year (294th in leap years) in the Gregorian calendar. ... 2008 (MMVIII) is the current year, a leap year that started on Tuesday of the Anno Domini (or common era), in accordance to the Gregorian calendar. ... is the 38th day of the year in the Gregorian calendar. ...

External links


  Results from FactBites:
 
Hydrogen sulfide - Wikipedia, the free encyclopedia (2004 words)
Hydrogen sulfide is corrosive and penetrates the lattice of some steels and makes them brittle, leading to sulphide stress cracking - a concern especially for handling acid gas and sour crude in the oil industry.
Metal sulfides should not to be confused with sulfites, which are derived from the sulfite ion SO Hydrogen sulfide burns to give the gas sulfur dioxide, which is more familiar to people as the odor of a burnt match.
Hydrogen sulfide is a central participant in the sulfur cycle, the biogeochemical cycle of sulfur on Earth.
Hydrogen sulfide - definition of Hydrogen sulfide in Encyclopedia (330 words)
S is a sulfide compound that has an unpleasant smell; it is responsible for the smell of rotten eggs.
Hydrogen sulfide is produced by the breakdown of sulfur-containing proteins and is responsible for much of the foul odor of feces and flatulence.
Hydrogen sulfide occurs naturally in crude petroleum, natural gas, volcanic gases, and hot springs.
  More results at FactBites »

 
 

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