oxygen

oxygen,

gaseous chemical element; symbol O; at. no. 8; interval in which at. wt. ranges 15.99903–15.99977; m.p. −218.4&degC;; b.p. −182.962&degC;; density 1.429 grams per liter at STP; valence −2. The existence and properties of oxygen had been noted by many scientists before the announcement of its isolation by Priestley in 1774. Scheele had also succeeded in preparing oxygen from a number of substances, but publication of his findings was delayed until after that of Priestley's. As a result, Priestley and Scheele are credited with the discovery of the element independently. The fact that the gas is a component of the atmosphere was finally and definitely established by Lavoisier a few years later. In 1929, W. F. Giaque and H. L. Johnston announced the discovery of two isotopes of oxygen, of mass numbers 17 and 18.

Properties and Compounds

Oxygen is a colorless, odorless, tasteless gas; it is the first member of Group 16 of the periodic tableperiodic table,
chart of the elements arranged according to the periodic law discovered by Dmitri I. Mendeleev and revised by Henry G. J. Moseley. In the periodic table the elements are arranged in columns and rows according to increasing atomic number (see the table entitled
..... Click the link for more information. . It is denser than air and only slightly soluble in water. A poor conductor of heat and electricity, oxygen supports combustion but does not burn. Normal atmospheric oxygen is a diatomic gas (O₂) with molecular weight 31.9988. Ozoneozone
, an allotropic form of the chemical element oxygen (see allotropy). Pure ozone is an unstable, faintly bluish gas with a characteristic fresh, penetrating odor. The gas has a density of 2.144 grams per liter at STP.
..... Click the link for more information. is a highly reactive triatomic (O₃) allotrope of oxygen (see allotropyallotropy
[Gr.,=other form]. A chemical element is said to exhibit allotropy when it occurs in two or more forms in the same physical state; the forms are called allotropes.
..... Click the link for more information. ). When cooled below its boiling point oxygen becomes a pale blue liquid; when cooled still further the liquid solidifies, retaining its color. Oxygen is paramagnetic in its solid, liquid, and gaseous forms. Although eight isotopes of oxygen are known, atmospheric oxygen is a mixture of the three isotopes with mass numbers 16, 17, and 18.

Oxygen is extremely active chemically, forming compounds with almost all of the elements except the inert gases. Oxygen unites directly with a number of other elements to form oxidesoxide,
chemical compound containing oxygen and one other chemical element. Oxides are widely and abundantly distributed in nature. Water is the oxide of hydrogen. Silicon dioxide is the major component of sand and quartz.
..... Click the link for more information. . It is a constituent of many acids and of hydroxides, carbohydrates, proteins, fats and oils, alcohols, cellulose, and numerous other compounds such as the carbonates, chlorates, nitrates and nitrites, phosphates and phosphites, and sulphates and sulphites.

The common reaction in which it unites with another substance is called oxidation (see oxidation and reductionoxidation and reduction,
complementary chemical reactions characterized by the loss or gain, respectively, of one or more electrons by an atom or molecule. Originally the term oxidation
..... Click the link for more information. ). The burning of substances in air is rapid oxidation or combustioncombustion,
rapid chemical reaction of two or more substances with a characteristic liberation of heat and light; it is commonly called burning. The burning of a fuel (e.g., wood, coal, oil, or natural gas) in air is a familiar example of combustion.
..... Click the link for more information. . The respirationrespiration,
process by which an organism exchanges gases with its environment. The term now refers to the overall process by which oxygen is abstracted from air and is transported to the cells for the oxidation of organic molecules while carbon dioxide (CO₂
..... Click the link for more information. of animals and plants is a form of oxidation essential to the liberation of the energy stored in such food materials as carbohydrates and fats. The rusting of iron and the corrosion of many metals results from the action of the oxygen in the air.

Natural Occurrence and Preparation

Oxygen is the most abundant element on earth, constituting about half of the total material of its surface. Most of this oxygen is combined in the form of silicates, oxides and water. It makes up about 90% of water, two thirds of the human body and one fifth by volume of air. It is found in the sun, and has a role in the stellar carbon cycle (see nucleosynthesisnucleosynthesis
or nucleogenesis,
in astronomy, production of all the chemical elements from the simplest element, hydrogen, by thermonuclear reactions within stars, supernovas, and in the big bang at the beginning of the universe (see nucleus; nuclear energy).
..... Click the link for more information. ). Oxygen is prepared for commercial use by the liquefaction and fractional distillation of air and more expensively by the electrolysis of water; it is stored and transported under high pressure in steel cylinders. It can also be obtained by heating certain of its compounds, such as barium peroxide, potassium chlorate, and the red oxide of mercury.

Uses

Oxygen is of great importance in the chemical and the iron and steel industries. Its major use is in steel production, for example in the Bessemer processBessemer process
[for Sir Henry Bessemer], industrial process for the manufacture of steel from molten pig iron. The principle involved is that of oxidation of the impurities in the iron by the oxygen of air that is blown through the molten iron; the heat of oxidation raises the
..... Click the link for more information. . The oxyacetylene torchoxyacetylene torch
, tool that mixes and burns oxygen and acetylene to produce an extremely hot flame. This torch can be used for cutting steel and for welding iron and various other metals. The temperature of the flame can reach as high as 6,300&degF; (3,480&degC;).
..... Click the link for more information. is another important industrial application. Oxygen is utilized in medicine in the treatment of respiratory diseases and is mixed with other gases for respiration in submarines, high-flying aircraft, and spacecraft. Liquid oxygen is used as an oxidizer in the fuel systems of large rockets.

Oxygen was formerly the official standard for the atomic weightsatomic weight,
mean (weighted average) of the masses of all the naturally occurring isotopes of a chemical element, as contrasted with atomic mass, which is the mass of any individual isotope. Although the first atomic weights were calculated at the beginning of the 19th cent.
..... Click the link for more information. of elements. The chemists used natural oxygen, a mixture of three isotopes, to which the value of 16 was assigned while the physicists assigned the value of 16 specifically to the oxygen isotope 16. In 1961 carbon-12 replaced oxygen as the standard.

Oxygen

O, a chemical element of group VI of Mendeleev’s periodic system. Atomic number, 8; atomic mass, 15.9994. Under normal conditions, oxygen is a colorless, tasteless, and odorless gas. It would be difficult to name another element that plays as important a role on earth as oxygen.

History. The processes of combustion and respiration have long attracted the attention of scientists. The first hints that not all of the air but only its “active” part supports combustion were found in Chinese eighth-century manuscripts. Much later, Leonardo da Vinci (1452–1519) regarded air as a mixture of two gases, of which only one is consumed during cumbustion and respiration. The ultimate discovery of the two principal constituents of air, nitrogen and oxygen, a discovery of epochal importance in science, was made only in the late 18th century. Oxygen was prepared almost simultaneously by K. Scheele (1769–70) by calcination of nitrates (KNO₃, NaNO₃), manganese dioxide (MnO₂), and other substances and by J. Priestley (1774) by the heating of red lead oxide, Pb₃O₄, and mercuric oxide, HgO. D. Rutherford discovered nitrogen in 1772. A. Lavoisier, performing a quantitative analysis of air, found that it “consists of two [gases] of different and, so to speak opposite character,” namely of oxygen and nitrogen. On the basis of extensive experimental studies, he correctly interpreted combustion and respiration as processes of the interaction of various substances and oxygen. Since oxygen in a constituent of acids, Lavoisier called it oxygène, that is, “acid former” (from the Greek oxys [acidic]) and gennao [I generate]; hence the Russian name kislorod, from kislyi [acidic] and rodif [to generate].

Distribution in nature. Oxygen is the most widespread element on earth. Combined oxygen constitutes about six-sevenths of the earth’s hydrosphere (85.82 percent by weight) and almost one-half of the lithosphere (47 percent by weight). Only in the atmosphere, where oxygen is present in the free state, is it the second most abundant element (23.15 percent by weight), after nitrogen.

Oxygen is also in first place in the number of minerals formed by it (1,364). The most widespread minerals containing oxygen are silicates (feldspars, micas), quartz, iron oxides, carbonates, and sulfates. Living organisms on the average contain about 70 percent oxygen; it is a constituent of most of the important organic compounds (proteins, fats, carbohydrates) and a component of the inorganic constituents of the skeleton. The role of free oxygen is especially important in biochemical and physiological processes, particularly in respiration. With the exception of some anaerobic microorganisms, all animals and plants receive the energy required by life processes from the biological oxidation of various substances with oxygen.

The entire mass of the free oxygen on earth originated from and is being maintained by the life activities of green plants, which evolve oxygen in the course of photosynthesis, on land and in the oceans. Photosynthesis and the dominance of free oxygen on the earth’s surface give rise to strongly oxidizing conditions. Conversely, reducing media are formed where oxygen is absent, as in magma, in deep levels of subterranean water, in the silt of the oceans and lakes, and in marshes. Reduction-oxidation processes with the participation of oxygen determine the concentration of many elements and the formation of such mineral deposits as coal, oil, sulfur, iron, and copper ores. The oxygen cycle is also changed by the economic activities of man. In some industrial countries more oxygen is consumed during fuel combustion than the amount evolved by the photosynthesis of plants. The annual oxygen consumption for combustion of fuels on the earth is about 9 X 19⁹ tons.

Isotopes, atoms, and molecules. Oxygen has three stable isotopes—¹⁶O, ¹⁷O, and ¹⁸O—the average content of which constitutes, respectively, 99.759 percent, 0.037 percent, and 0.204 percent of the total number of oxygen atoms on the earth. The predominance of the lightest isotope ¹⁶O in the isotope mixture is due to the ¹⁶O nucleus consisting of eight protons and eight neutrons. The theory of the atomic nucleus indicates that such nuclei are particularly stable.

In accordance with oxygen’s position in Mendeleev’s periodic system of elements, the electrons of the oxygen atom are arranged in two shells: two in the inner shell and six in the outer shell (configuration Is²2s²2p⁴). Since the outer shell is not filled and the ionization potential and the electron affinity are 12.61 and 1.46 eV, respectively, the oxygen atom usually acquires electrons in the course of formation of chemical compounds and has a negative effective charge. Conversely, rare are the compounds in which electrons are torn away (or more precisely, pulled away) from the oxygen atom (as in F₂O and F₂O₂). In the past, proceeding solely from the position of oxygen in the periodic system, a negative charge ( — 2) was ascribed to the oxygen atom. However, experimental data have indicated that the ion O^2- does not exist either in the free state or in compounds and that the effective negative charge of the oxygen atom practically never exceeds unity.

Under ordinary conditions, the oxygen molecule is diatomic (O₂). A triatomic molecule, ozone (O₃), is formed in a silent electric discharge; small amounts of tetratomic molecules (O₄) have been detected at high pressures. The electronic structure of O₂ is of great theoretical interest. The molecule has two unpaired electrons in the ground state; the usual “classical” structural formula O ⇄ O with two two-electron bonds is inapplicable to it. An exhaustive explanation of this fact is provided by the theory of molecular orbitals.

The ionization energy of the oxygen molecule (O₂ — e → O⁺₂) constitutes 12.2 eV, and the electron affinity (O₂ + e → O^-₂)> 0.94 eV. The dissociation of molecular oxygen into atoms is negligible at ordinary temperatures, becoming noticeable only at 1500°C; at 5000°C the oxygen molecules are almost completely dissociated into atoms.

Physical properties. Oxygen is a colorless gas that liquifies at — 182.9°C and normal pressure to a pale blue liquid, which, in turn, solidifies at — 218.7°C forming blue crystals. The density of gaseous oxygen (at 0°C and normal pressure) is 1.42897 g/l. The critical temperature of oxygen is fairly low (t_Crit = -118.84°C), that is, lower than that of Cl₂, CO₂, SO₂, and some other gases; P_crit = 4.97 meganewtons per square meter (49.71 atm). The heat conductivity (at 0°C) is 23.86 X 10^-3 W/(m.°K), or 57 X 10^-6 cal/(sec · cm.°C). The molar heat capacities (at 0°C) are C_p = 28.9 and C_v = 20.5 in joules (mole·°K) and C_p = 6.99 and C_v = 4.98 in cal/(mole· °C), respectively; C_P/C_V = 1.403. The dielectric permeability of gaseous oxygen is 1.000547 (at 0°C), and of liquid oxygen 1.491. The viscosity is 189 millipoises (at 0°C). Oxygen is poorly soluble in water: at 20°C and 1 atm, 0.031 m³ dissolves in 1 m³ of water; 0.049 m³ dissolves at 0°C. Platinum black and activated charcoal are efficient solid absorbents for oxygen.

Chemical properties. Oxygen forms chemical compounds with all other elements except the light inert gases. Being the most active nonmetal (after fluorine), oxygen interacts directly with most elements. The only exceptions are the heavy inert gases, the halogens, gold, and platinum; their compounds with oxygen are obtained by indirect methods. Almost all of the reactions involving oxygen are exothermic oxidation reactions, that is, accompanied by the evolution of heat. Oxygen reacts with hydrogen at ordinary temperatures very slowly, whereas this reaction proceeds explosively above 550°C: 2H₂ + O₂ = 2H₂O. Oxygen reacts with sulfur, carbon, nitrogen, and phosphorus very slowly under ordinary conditions. The reaction rate increases with increasing temperature until at an ignition temperature characteristic for each element combustion occurs. The reaction of oxygen with nitrogen is endothermic because of the particular stability of the N₂ molecule and becomes noticeable only above 1200°C or in an electric discharge: N₂ + O₂ = 2NO. Oxygen actively oxidizes almost all metals and, with particular ease, the alkali and alkaline-earth metals. The reactivity of a metal with oxygen depends on many factors, such as the condition of the metal surface, the degree of subdivision, and the presence of impurities.

The role of water is of particular importance in the interaction of substances with oxygen. For example, such an active metal as potassium does not react at all with oxygen that is completely devoid of moisture, but it ignites in oxygen at room temperature in the presence of the minutest quantities of water vapor. It has been calculated that the annual loss owing to corrosion amounts to as much as 10 percent of the entire metal production.

Oxides of some metals form peroxides by the addition of oxygen. The resulting compounds contain two or more oxygen atoms bonded to each other. Thus, the peroxides Na₂O₂ and BaO₂ contain the peroxide ion O₂^2-, the superoxides NaO₂ and KO₂ contain the ion O_2-, and the ozonides NaO₃, KO₃, RbO₃, and CsO₃ contain the ion O_3-. Oxygen reacts exothermally with numerous complex substances. Thus, ammonia burns in oxygen in the absence of catalysts, the reaction proceeding according to the equation 4NH₃ X 3O₂ = 2N₂ X 6H₂O. Oxidation of ammonia with oxygen in the presence of catalysts yields NO (this process is used in the production of nitric acid). Of particular importance is the combustion of hydrocarbons (natural gas, gasoline, kerosene), which constitutes the most important heat source for consumers and industry; for example, CH₄ + 2O₂ = CO₂ + 2H₂O. The reaction of hydrocarbons with oxygen forms the basis of many important industrial processes, such as the reforming of methane, which is used for the production of hydrogen: 2CH₄ + O₂ + 2H₂O = 2CO₂ + 6H₂. Many organic compounds (hydrocarbons with double and triple bonds, aldehydes, phenols, turpentine, drying oils) vigorously add oxygen. The oxidation of nutrients with oxygen in the cells serves as a source of energy for living organisms.

Preparation. There are three basic methods for preparing oxygen: chemical, electrolytic (electrolysis of water), and physical (separation of air).

The chemical method was discovered first. Oxygen may be prepared, for example, from potassium chlorate, KClO₃, which decomposes on heating with evolution of O₂ in amounts of 0.27 m³ per 1 kg of the salt. Barium oxide, BaO, absorbs oxygen at first, when heated up to 540°C, to give the peroxide BaO₂, which decomposes on further heating to 870°C with the evolution of pure oxygen. It may be also obtained from KMnO₄, Ca₂PbO₄, K₂Cr₂O₇, and other substances by heating in the presence of catalysts. The chemical method of preparing oxygen is inefficient and expensive and is used only in laboratory practice.

The electrolytic method consists of passing a direct electric current through water containing a solution of sodium hydroxide, NaOH, to increase its conductivity. In this case, water is decomposed into oxygen and hydrogen. The oxygen is collected at the positive electrode of the electrolysis unit, and the hydrogen at the negative electrode. Oxygen is obtained in this method as a byproduct of hydrogen manufacture. The expenditure of 12–15 kW-hr of electric energy is required for the production of 2 m³ of hydrogen and 1 m³ of oxygen.

The principal method for the production of oxygen in modern technology is the separation of air. To separate air in its normal gaseous state is very difficult and, therefore it is first liquified and then separated into components. This method for the production of oxygen is known as the low-temperature method of air separation. The air is first compressed with a compressor and then, after passing through heat exchangers, expanded in an expansion turbine or through a nozzle; this leads to its cooling to 93°K (—180°C) and conversion to liquid air. Further separation of liquid air, consisting primarily of liquid nitrogen and liquid oxygen, is based on the boiling point differences of its components (the boiling point of O₂ is 90.18°K [-182.9°C], and that of N₂, 77.36°K [-195.8°C]). Gradual evaporation of liquid air leads, at first, to the evaporation of mainly nitrogen, and the remaining liquid becomes ever more enriched in oxygen. Continuous repetition of this process on the rectification plates of the air-separator columns yields liquid oxygen of the required purity (concentration).

The smallest (capacity of several liters) and largest oxygen air-separation units (35,000 m³/hr of oxygen) in the world have been constructed in the USSR. The units are used in the production of industrial oxygen with a concentration of 95–98.5 percent, technical-grade oxygen with a concentration of 99.2–99.9, and the higher purity oxygen used in medicine. The product may be gaseous or liquified oxygen. The expenditure of electric energy ranges from 0.41 to 1.6 kW-hr/m³.

It is also possible to prepare oxygen by separating air using the method of selective permeation (diffusion) through membrane barriers. Air under pressure is passed through barriers made of fluorocarbons, glass, or plastics, the structural lattices of which are capable of allowing some components to pass through while retaining others. This method of oxygen production has been used to date (1973) only in laboratories.

Gaseous oxygen is stored and transported in steel cylinders and receivers at pressures of 15 and 42 meganewtons per square meter (corresponding to 150 and 420 bars, or 150 and 420 atm, respectively). Liquid oxygen is stored and shipped in metal Dewar vessels or in special tanks. Special pipelines are also used for transporting liquid and gaseous oxygen. Oxygen cylinders are painted light blue and are labeled “oxygen” in black.

Uses. Technical-grade oxygen is used in the gaseous flame working of metals, in welding, in oxygen cutting, in case hardening, in metallization, and in other processes, as well as in aviation, in underwater navigation, and elsewhere. Industrial oxygen is used in the chemical industry for the production of such products as synthetic liquid fuels, lubricating oils, nitric and sulfuric acids, methanol, ammonia, ammonia fertilizers, and peroxides of metals. Liquid oxygen is used in working with explosives, in rocket engines, and in laboratory applications as a cooling agent.

Pure cylinder oxygen is used for breathing at high altitudes, during space flights, and in underwater navigation. In medicine, oxygen is administered intramuscularly and to aid the respiration of the gravely ill; it is also used in oxygen, water, and air baths (in oxygen tents).

V. L. VASILEVSKII I. P. VISHNEV, and A. I. PEREL’MAN

Oxygen is widely used in metallurgy for the enhancement of various pyrometallurgical processes. A full or partial replacement of air fed to metallurgical aggregates with oxygen has changed the chemism of processes, their heat-engineering parameters, and engineering economics indexes. Oxygen blasting has made it possible to reduce heat losses with outgoing gases, which in air blasting largely consisted of nitrogen. Without participating significantly in the chemical processes, nitrogen retarded the reactions by lowering the concentration of the active reagents of the oxidation-reduction medium. Blasting with oxygen lowers the fuel consumption and improves the quality of the metal; new types of production becomes possible in metallurgical aggregates (for example, of slags and gases, which are unusual in composition for a given process and which find special industrial uses).

The first experiments in the use of blast enriched with oxygen in blast-furnace production for the smelting of cast iron for steel production and of ferromanganese were performed simultaneously in the USSR and Germany in 1932–33. The increased oxygen content in the blast of blast furnaces is accompanied by a considerable reduction in the consumption of the oxygen and the simultaneous increase of the carbon monoxide content of the blast-furnace gases and its heat of combustion. Enrichment of the blast with oxygen has made it possible to increase the productivity of the blast furnace and, together with the gaseous or liquid fuel fed to the furnace, leads to a decrease of the coke consumption. In this case, for each additional percent of oxygen in the blast, the productivity increases by about 2.5 percent, and the consumption of coke decreases by 1 percent.

Oxygen in open-hearth production in the USSR was first used to increase fuel combustion efficiency (the first industrial uses of oxygen for this purpose were at the Serp i Molot and the Krasnoe Sormovo plants in 1932–33). The first blasting of oxygen into the bath was begun in 1933 to oxidize the impurities in the final stages. An increase in blasting intensity of the melt to 1 m³/ton/hr leads to a 5–10 percent increase in furnace productivity and a 4–5 percent decrease in fuel consumption. However, metal losses increase during the blasting. An oxygen consumption of up to 10 m³ton/hr leads to an insignificant decrease in the yield of steel (up to 1 percent). Oxygen is finding increasing use in open-hearth production. Thus, while 52.1 percent of steel was produced in 1965 using oxygen in open-hearth furnaces, 71 percent was produced in 1971.

Experiments in the use of oxygen in electric-arc steel-smelting furnaces in the USSR were begun in 1946 at the Elektrostal’ Plant. Adoption of oxygen blasting has made it possible to increase furnace productivity by 25–30 percent, to decrease the specific consumption of electric energy by 20–30 percent, to improve the quality of steel, and to reduce the consumption of electrodes and certain alloys in short supply. Feeding oxygen into electric furnaces proved to be especially effective in the production of stainless steel of low carbon content, which is difficult to manufacture owing to the carburizing effect of the electrodes. The quantity of electric steel being produced in the USSR using oxygen is continuously increasing and in 1970 constituted 74.6 percent of the overall steel production.

In cupola furnace smelting, oxygen-enriched blast is mainly used to superheat cast iron, which is necessary in the production of high-quality melts, particularly highly alloyed ones (with silicon, chromium, and other metals). Depending on the extent of oxygen enrichment of the cupola furnace, the fuel consumption is reduced by 30–50 percent, the sulfur content of the metal is reduced by 30–40 percent, the productivity of the cupola furnace is increased by 80–100 percent, and the temperature of the resulting cast iron is substantially increased (up to 1500°C).

The use of oxygen in nonferrous metallurgy was begun somewhat later than in ferrous metallurgy. The blasting air enriched in oxygen is used in the conversion of mattes, in the slag sublimation process, in the rotary-kiln process, in the agglomeration process, and in the reverberatory smelting of copper concentrates. Oxygen blasting in lead, nickel, and copper production has increased the efficiency of shaft smelting by reducing coke consumption by 10–20 percent, increasing the output by 15–20 percent, and reducing the flux quantity in some cases by a factor of 2–3. An increase of up to 30 percent in the oxygen content of the air blast used in the smelting of zinc sulfide concentrates has led to a 70 percent increase in production and a 30-percent reduction in the volume of outgoing gases. New, highly efficient processes are being developed for the smelting of sulfide materials using pure oxygen: smelting in an oxygen jet, conversion of mattes in vertical converters, and smelting in molten baths.

S. G. AFANAS’EV

REFERENCES

Chugaev, L. A. Otkrytie kisloroda i teoriia goreniia v sviazi s filosofskimi ucheniiami drevnego mira. Izbr. trudy, vol. 3. Moscow, 1962. Page 350.
Cotton, F., and G. Wilkinson. Sovremennaia neorganicheskaia khimiia, vols. 1–3. Moscow, 1969. (Translated from English.)
Nekrasov, B. V. Osnovy obshchei khimii, vol. 1. Moscow, 1965.
Kislorod, parts 1–2. A handbook edited by D. L. Glizmanenko. Moscow, 1967.
Razdelenie vozdukha metodom glubokogo okhlazhdeniia, vols. 1–2. Edited by V. I. Epifanova and L. S. Aksel’rod. Moscow, 1964.
Spravochnik po fiziko-tekhnicheskim osnovam glubokogo okhlazhdeniia. Moscow-Leningrad, 1963.

oxygen

[′äk·sə·jən] (chemistry) A gaseous chemical element, symbol O, atomic number 8, and atomic weight 15.9994; an essential element in cellular respiration and in combustion processes; the most abundant element in the earth's crust, and about 20% of the air by volume.

oxygen

In its free form, a colorless, tasteless, and odorless gaseous element. The second most abundant gas in the earth's atmosphere and a prerequisite for virtually all forms of animal life. It makes up 20.946% of dry air by volume, and its molecular formula is O₂. Oxygen is present primarily in molecular form up to an altitude of about 12 miles (20 km) and above that, as atomic oxygen as a result of photo dissociation.

oxygen

a. a colourless odourless highly reactive gaseous element: the most abundant element in the earth's crust (49.2 per cent). It is essential for aerobic respiration and almost all combustion and is widely used in industry. Symbol: O; atomic no.: 8; atomic wt.: 15.9994; valency: 2; density: 1.429 kg/m³; melting pt.: --218.79?C; boiling pt.: --182.97?C b. (as modifier): an oxygen mask

oxygen

Oxygen/Ozone Therapy

Definition

Oxygen/ozone therapy is a term that describes a number of different practices in which oxygen, ozone, or hydrogen peroxide are administered via gas or water to kill disease microorganisms, improve cellular function, and promote the healing of damaged tissues. The rationale behind bio-oxidative therapies, as they are sometimes known, is the notion that as long as the body's needs for antioxidants are met, the use of certain oxidative substances will stimulate the movement of oxygen atoms from the bloodstream to the cells. With higher levels of oxygen in the tissues, bacteria and viruses are killed along with defective tissue cells. The healthy cells survive and multiply more rapidly. The result is a stronger immune system.Ozone itself is a form of oxygen, O3, produced when ultraviolet light or an electric spark passes through air or oxygen. It is a toxic gas that creates free radicals, the opposite of what antioxidant vitamins do. Oxidation, however, is good when it occurs in harmful foreign organisms that have invaded the body. Ozone inactivates many disease bacteria and viruses.

Purpose

Oxygen and ozone therapies are thought to benefit patients in the following ways:

stimulating white blood cell production
killing viruses (ozone and hydrogen peroxide)
improving the delivery of oxygen from the blood stream to the tissues of the body
speeding up the breakdown of petrochemicals
increasing the production of interferon and tumor necrosis factor, thus helping the body to fight infections and cancers
increasing the efficiency of antioxidant enzymes
increasing the flexibility and efficiency of the membranes of red blood cells
speeding up the citric acid cycle, which in turn stimulates the body's basic metabolism

Description

Origins

The various forms of oxygen and ozone therapy have been in use since the late nineteenth century. The earliest recorded use of oxygen to treat a patient was by Dr. J. A. Fontaine in 1879. In the 1950s, hyperbaric oxygen treatment was used by cancer researchers. The term "hyperbaric" means that the oxygen is given under pressure higher than normal air pressure. Recently, oxygen therapy has also been touted as a quick purification treatment for mass-market consumers. Oxygen bars can be found in airports and large cities, and provide pure oxygen in 20-minute sessions for approximately $16. While proponents claim that breathing oxygen will purify the body, most medical doctors do not agree. What is more, oxygen can be harmful to people with severe lung diseases, and these people should never self-treat with oxygen.Ozone has been used since 1856 to disinfect operating rooms in European hospitals, and since 1860 to purify the water supplies of several large German cities. Ozone was not, however, used to treat patients until 1915, when a German doctor named Albert Wolff began to use it to treat skin diseases. During World War I, the German Army used ozone to treat wounds and anaerobic infections. In the 1950s, several German physicians used ozone to treat cancer alongside mainstream therapeutic methods. It is estimated that as of the late 1990s, about 8,000 practitioners in Germany were using ozone in their practices. This figure includes medical doctors as well as naturopaths and homeopaths.Hydrogen peroxide is familiar to most people as an over-the-counter preparation that is easily available at supermarkets as well as pharmacies, and is used as an antiseptic for cleansing minor cuts and scrapes. It was first used as an intravenous infusion in 1920 by a British physician in India, T. H. Oliver, to treat a group of 25 Indian patients who were critically ill with pneumonia. Oliver's patients had a mortality rate of 48%, compared to the standard mortality rate of 80% for the disease. In the 1920s, an American physician named William Koch experimented with hydrogen peroxide as a treatment for cancer. He left the United States after a legal battle with the FDA. In the early 1960s, researchers at Baylor University studied the effects of hydrogen peroxide in removing plaque from the arteries as well as its usefulness in treating cancer, but their findings were largely ignored.Oxygen, ozone, and hydrogen peroxide are used therapeutically in a variety of different ways.

Hyperbaric oxygen therapy (hbo)

Hyperbaric oxygen therapy (HBO) involves putting the patient in a pressurized chamber in which he or she breathes pure oxygen for a period of 90 minutes to two hours. HBO may also be administered by using a tight-fitting mask, similar to the masks used for anesthesia. A nasal catheter may be used for small children.

Ozone therapy

Ozone therapy may be administered in a variety of ways.

Intramuscular injection: A mixture of oxygen and ozone is injected into the muscles of the buttocks.
Rectal insufflation: A mixture of oxygen and ozone is introduced into the rectum and absorbed through the intestines.
Autohemotherapy: Between 10-15 mL of the patient's blood is removed, treated with a mixture of oxygen and ozone and reinjected into the patient.
Intra-articular injection: Ozone-treated water is injected into the patient's joints to treat arthritis, rheumatism and other joint diseases.
Ozonated water: Ozone is bubbled through water that is used to cleanse wounds, burns, and skin infections, or to treat the mouth after dental surgery.
Ozonated oil: Ozone is bubbled through olive or safflower oil, forming a cream that is used to treat fungal infections, insect bites, acne, and skin problems.
Ozone bagging: Ozone and oxygen are pumped into an airtight bag that surrounds the area to be treated, allowing the body tissues to absorb the mixture.

Hydrogen peroxide

Hydrogen peroxide may be administered intravenously in a 0.03% solution. It is infused slowly into the patient's vein over a period of one to three hours. Treatments are given about once a week for chronic illness but may be given daily for such acute illnesses as pneumonia or influenza. A course of intravenous hydrogen peroxide therapy may range from one to 20 treatments, depending on the patient's condition and the type of illness being treated. Injections of 0.03% hydrogen peroxide have also been used to treat rheumatoid and osteoarthritis. The solution is injected directly into the inflamed joint.Hydrogen peroxide is also used externally to treat stiff joints, psoriasis, and fungal infections. The patient soaks for a minimum of 20 minutes in a tub of warm water to which 1 pint of 35% food-grade hydrogen peroxide (a preparation used by the food industry as a disinfectant) has been added.

Preparations

Oxygen is usually delivered to the patient as a gas; ozone as a gas mixed with oxygen or bubbled through oil or water; and hydrogen peroxide as an 0.03% solution for intravenous injection or a 35% solution for external hydrotherapy.

Precautions

Patients interested in oxygen/ozone therapies must consult with a physician before receiving treatment. Hyperbaric oxygen treatment should not be given to patients with untreated pneumothorax, a condition in which air or gas is present in the cavity surrounding the lungs. Patients with a history of pneumothorax, chest surgery, emphysema, middle ear surgery, uncontrolled high fevers, upper respitory infections, seizures, or disorders of the red blood cells are not suitable candidates for oxygen/ozone therapy. In addition, patients should be aware that oxygen is highly flammable. If treatments are administered incorrectly or by an unskilled person, there is a risk of fire.

Side effects

Typical side effects of oxygen or ozone therapy can include elevated blood pressure and ear pressure similar to that experienced while flying. Side effects may also include headache, numbness in the fingers, temporary changes in the lens of the eye, and seizures.

Research and general acceptance

Oxygen/ozone therapies are far more widely accepted in Europe than in the United States. The most intensive research in these therapies is presently being conducted in the former Soviet Union and in Cuba. In the United States, the work of the Baylor researchers was not followed up. In 2000, the Office of Alternative Medicine of the National Institutes of Health (presently the National Center for Complementary and Alternative Medicine, or NCCAM) indicated interest in conducting clinical trials of oxygen/ozone therapies; as of 2003, however, these studies have not been carried out.Recent European research in ozone therapy includes studies in the oxygenation of resting muscles, the treatment of vascular disorders, and the relief of pain from herniated lumbar disks. No corresponding studies are being done in the United States as of late 2003.

Key terms

Autohemotherapy — A form of ozone therapy in which a small quantity of the patient's blood is withdrawn, treated with a mixture of ozone and oxygen, and reinfused into the patient.Hydrogen peroxide — A colorless, unstable compound of hydrogen and oxygen (H₂O₂). An aqueous solution of hydrogen peroxide is used as an antiseptic and bleaching agent.Hyperbaric oxygen therapy (HBO) — A form of oxygen therapy in which the patient breathes oxygen in a pressurized chamber.Ozone — A form of oxygen with three atoms in its molecule (O₃), produced by an electric spark or ultraviolet light passing through air or oxygen. Ozone is used therapeutically as a disinfectant and oxidative agent.

Resources

Periodicals

Andreula, C. F., L. Simonetti, F. De Santis, et al. "Minimally Invasive Oxygen-Ozone Therapy for Lumbar Disk Herniation." American Journal of Neuroradiology 24 (May 2003): 996-1000.Clavo, B., J. L. Perez, L. Lopez, et al. "Effect of Ozone Therapy on Muscle Oxygenation." Journal of Alternative and Complementary Medicine 9 (April 2003): 251-256.Tylicki, L., T. Nieweglowski, B. Biedunkiewicz, et al. "The Influence of Ozonated Autohemotherapy on Oxidative Stress in Hemodialyzed Patients with Atherosclerotic Ischemia of Lower Limbs." International Journal of Artificial Organs 26 (April 2003): 297-303.

Organizations

International Bio-Oxidative Medicine Foundation (IBOMF). P.O. Box 891954. Oklahoma City, OK 73109. (405) 634-7855. Fax (405) 634-7320.International Ozone Association, Ind. Pan American Group. 31 Strawberry Hill Ave. Stamford, CT 06902. (203) 348-3542. Fax (203) 967-4845.NIH National Center for Complementary and Alternative Medicine (NCCAM). NCCAM Clearinghouse. P. O. Box 8218. Silver Spring, MD 20907-8218. TTY/TDY: (888) 644-6226. http://nccam.nih.gov.

Other

Oxygen Healing Therapies. http://www.oxygenhealingtherapies.com.

oxygen

(O) [ok´sĭ-jen] a chemical element, atomic number 8, atomic weight 15.999. (See Appendix 6.) It is a colorless and odorless gas that makes up about 20 per cent of the atmosphere. In combination with hydrogen, it forms water; by weight, 90 per cent of water is oxygen. It is the third most abundant of all the elements of nature. Large quantities of it are distributed throughout the solid matter of the earth because it combines readily with many other elements. With carbon and hydrogen, oxygen forms the chemical basis of much organic material. Oxygen is essential in sustaining all kinds of life. Among the land animals, it is obtained from the air and drawn into the lungs by the process of respiration. See also blood gas analysis.Oxygen Balance and “Oxygen Debt.” The need of every cell for oxygen requires a balance in supply and demand. But this balance need not be exact at all times. In fact, in strenuous exercise the oxygen needs of muscle cells are greater than the amount the body can absorb even by the most intense breathing. Thus, during athletic competition, the participants make use of the capacity of muscles to function even though their needs for oxygen are not fully met. When the competition is over, however, the athletes will continue to breathe heavily until the muscles have been supplied with sufficient oxygen. This temporary deficiency is called oxygen debt.
Severe curtailment of oxygen, as during ascent to high altitudes or in certain illnesses, may bring on a variety of symptoms of hypoxia, or oxygen lack. A number of poisons, such as cyanide and carbon monoxide,, as well as large overdoses of sedatives, disrupt the oxygen distribution system of the body. Such disruption occurs also in various illnesses, such as anemia and diseases of lungs, heart, kidneys, and liver.oxygen 15 an artificial radioactive isotope of oxygen having a half-life of 2.04 minutes and decaying by positron emission. It is used as a tracer in the measurement of regional blood volume and flow and oxygen metabolism by tomography" >positron emission tomography.oxygen analyzer an instrument that measures the concentration of oxygen in a gas mixture. There are three types of handheld analyzers: physical/paramagnetic, electric, and electrochemical analyzers.oxygen blender a device used to mix oxygen with other gases to any concentration between 21 per cent and 100 per cent.oxygen concentrator an electronic device that removes nitrogen from room air, thus increasing the oxygen concentration; commonly used by patients who require long-term oxygen administration at home.oxygen consumption the amount of oxygen consumed by the tissues of the body, usually measured as the oxygen uptake in the lung. The normal value is 250 ml/min (or 3.5 to 4.0 ml/kg/min), and it increases with increased metabolic rate.oxygen hood a device that fits over the head of an infant or small child for administration of oxygen or aerosolized medications.hyperbaric oxygen oxygen under greater than atmospheric pressure.liquid oxygen oxygen in liquid form, a common storage form of oxygen; one liter of liquid oxygen will produce 860 liters of gas.oxygen tent a large plastic canopy that encloses the patient in a controlled environment, formerly much used for oxygen therapy, humidity therapy, or aerosol therapy.oxygen therapy 1. in the nursing interventions classification, a intervention" >nursing intervention defined as administration of oxygen and monitoring of its effectiveness.2. a form of respiratory care involving administration of supplemental oxygen for relief of hypoxemia and prevention of damage to the tissue cells as a result of oxygen lack (hypoxia). Oxygen can be toxic and therefore, as with a drug, its dosage and mode of administration are based on an assessment of the needs of the individual patient. Although many types of hypoxia can be treated successfully by the administration of oxygen, not all cases respond to this therapy. There also is the possibility that the injudicious use of oxygen can produce serious and permanent damage to the body tissues. The administration of oxygen should never be considered a “routine” or harmless procedure.Adverse Effects of Oxygen. Although it is true that all living organisms require oxygen to maintain life, an environment of 100 per cent oxygen inhibits growth of living tissue cultures, and laboratory experiments have shown that hyperoxygenation of body tissues can cause irreversible damage. It is known that high concentrations of inhaled oxygen can result in collapse of alveoli because of displacement of nitrogen by oxygen. retinopathy of prematurity in premature infants was found to be caused in part by excessively high levels of oxygen in the blood.
Another serious complication of high-oxygen concentration therapy is the development of a membrane" >hyaline membrane because of a deficiency of pulmonary surfactant; surfactant is vitally important to normal expansion and deflation of the alveoli. Prolonged exposure to inspired oxygen concentrations in excess of 50 per cent can impair the production of this surfactant in a patient of any age. The result is a loss of lung compliance and reduction of the transport of oxygen across the alveolar membrane.
The danger of oxygen toxicity can be minimized by careful assessment of each patient's need for oxygen therapy and systematic blood gas analysis" >blood gas analysis to determine patient response and effectiveness of treatment. Symptoms of oxygen toxicity are substernal distress, nausea and vomiting, malaise, fatigue, and numbness and tingling of the extremities.Indications for Oxygen Therapy. In general, the clinical situations in which the administration of supplemental oxygen is indicated are: (1) Profound but potentially reversible hypoxia that appears amenable to the short-term administration of high concentrations of oxygen. Examples would include the patient who is apneic, is suffering from cardiovascular collapse, or is a victim of carbon monoxide poisoning. (2) Conditions in which there is a need to reduce the work load of the cardiovascular and pulmonary systems and at the same time assure an adequate supply of oxygen to the tissues. Congestive heart failure, myocardial infarction, and such acute pulmonary diseases as pulmonary embolism and pneumonia are examples of the types of clinical situations that are best treated by the administration of moderate levels of oxygen concentration. (3) Evidence of hypoventilation, whether from anesthesia and sedation, chronic obstructive pulmonary disease, or other conditions. The patient who is hypoventilating is in danger of suffering from an adverse effect of oxygen therapy because increased oxygenation can lead to decreased respiratory effort. In other words, the oxygen acts as a respiratory depressant and may produce an increase in partial pressure of carbon dioxide in the arterial blood, thus contributing to rather than overcoming the problem of hypoxia. If there is evidence that the patient is hypoventilating, it may be necessary to administer the oxygen by assisted or controlled ventilation.
The delivery of appropriate and effective oxygen therapy requires frequent monitoring of arterial blood gases. An initial blood gas analysis at the time the therapy is started provides baseline data with which to evaluate changes in the patient's status.
In addition to monitoring blood gases to assess the patient's need for and response to supplemental oxygen, it is helpful to observe the patient closely for signs of hypoxemia. However, these signs are not as reliable as blood gas analysis because the clinical manifestations of hypoxemia vary widely in individual patients. The typical clinical manifestations of hypoxemia are confusion, impaired judgment, restlessness, tachycardia, central cyanosis, and loss of consciousness.Dosage and Method of Administration. It must be kept in mind that oxygen is considered a drug and should be prescribed and administered as such; thus it is apparent that vague orders about its administration are never acceptable. There must be specific written orders for flow rate and mode of administration. Decisions about the initial dosage, as well as any changes in mode of administration and dosage, including the discontinuance of oxygen therapy, should be based on evaluation of the P_O_₂, the P_CO_₂, and the blood pH. (See also transcutaneous oxygen monitoring and oximeter" >pulse oximeter.)
The clinical signs and symptoms of hypoxemia may vary from patient to patient, and they should not be depended upon as valid indications of oxygen insufficiency. This is especially true of cyanosis, a symptom that depends on local circulation to the area, the red cell count, and hemoglobin level. In addition to the data obtained from blood gas analyses, an oxygen analyzer should be used occasionally to check inspired oxygen concentration.
In general, the dosage and mode of administration fall into the following categories. High concentrations above 50 per cent usually are prescribed when there is a need for the delivery of high levels of oxygen for a short period of time to overcome acute hypoxemia, as in cardiovascular failure and pulmonary edema. The flow rate may be as high as 12 liters per minute, administered through a close-fitting face mask with or without a rebreathing bag, or via an endotracheal tube.
Moderate concentrations of oxygen are indicated when the patient is suffering from impaired circulation of oxygen, as in congestive heart failure and pulmonary embolism, or from increased need for oxygen, as in thyrotoxicosis, in which the increased metabolic rate creates a need for more oxygen. The rate of flow should be 4 to 8 liters per minute, administered through an air entrainment mask that delivers concentrations above 23 per cent, or in a dosage of 3 to 5 liters per minute through a nasal cannula.
Low concentrations of oxygen are indicated when the patient is receiving oxygen therapy over an extended period of time, as in chronic obstructive pulmonary disease, and there is the possibility of hypoventilation and the danger of increased CO₂ retention. The rate of flow should be 1 to 2 liters per minute, administered through a nasal cannula, or via an air entrainment mask that delivers 24 to 35 per cent oxygen.
Other methods of oxygen administration include the nasal catheter and the oxygen tent. The nasal catheter can cause some discomfort to the patient, and since it is no more and no less effective than the cannula, most therapists and patients prefer not to use it. The oxygen tent is considered by many to be obsolete, its use being limited to the administration of oxygen to children who cannot or will not tolerate other modes of delivery, and to children in whom the objective is to provide oxygen and humidity or humidity alone.Patient Care. No matter what mode of administration is used, it is essential that the inspired air be moisturized. This is necessary to prevent drying of the respiratory mucosa and thickening of secretions that can further inhibit the flow of air through the air passages. Humidity may be provided by humidifying the oxygen with water, or by aerosoling the water into fine particles and adding it to the oxygen. Most patients need 60 to 65 per cent relative humidity at room temperature. Patients with endotracheal tubes require as close to 100 per cent humidity as possible.
Oxygen is not an explosive gas, but it does support combustion and presents a serious fire hazard. All electrical equipment should be checked for defects that could produce sparks. All appliances that transmit house current must be kept outside an oxygen tent, and all equipment with exposed switches and meters must be considered potential sources of fire. Static electricity is a minimal risk which can be further reduced by maintaining a relatively high humidity in the oxygen tent. Smoking in the immediate area of oxygen administration is prohibited and there should be signs informing visitors and others of this restriction.
When the patient is wearing a mask for an extended period of time, discomfort can be minimized by removing the mask and washing and drying the face at least every eight hours. To be effective the mask must fit snugly and follow the contour of the face. This means that reddened areas will appear where the mask has pressed against the skin. These areas should be gently massaged and the skin lightly powdered to reduce friction.
A program of infection control is especially important in the prevention of cross-infection from the equipment that is used to administer oxygen. Humidifiers and nebulizers may serve as sources of infection because they provide a medium for the growth of bacteria and molds. There is less danger of this happening when disposable equipment is used, but this does not preclude the need for a systematic development of policies and procedures to prevent and control the spread of infection. Every person involved in the care of the patient must be aware of this program and cooperate in its implementation.transcutaneous oxygen monitoring a method for obtaining data about oxygen levels through electrodes attached to the skin. This method is preferred for ill neonates who cannot tolerate frequent drawing of blood samples for blood gas analysis. The P_O_₂ levels obtained by cutaneous monitoring correlate with those obtained from samples of arterial blood and spare the neonate blood loss and interruption of rest.
The transcutaneous electrodes are heated to encourage an adequate supply of blood to the area of skin to which they are attached and remain in place to permit continuous monitoring of arterial oxygen levels. To avoid burns, the electrode site can be changed every two hours. An ongoing record provides information about the neonate's oxygen level at any given moment. It allows caregivers to observe the neonate's response to handling and other procedures that may require modification to avoid severe anoxia. Placing the electrodes at specific sites can also aid the diagnosis of patent ductus arteriosus.

ox·y·gen (O),

(ok'si-jen), 1. A gaseous element, atomic no. 8, atomic wt. 15.9994 on the basis of ¹²C = 12.0000; an abundant and widely distributed chemical element, which combines with most other elements to form oxides and is essential to animal and plant life. 2. The molecular form of oxygen, O₂, also called dioxygen. 3. A medicinal gas that contains not less than 99.0%, by volume, of O₂. [G. oxys, sharp, acid and genes, forming]

ox·y·gen

(O) (ok'si-jĕn) 1. A gaseous element, atomic no. 8, atomic wt. 15.9994 on basis of ¹²C = 12.0000; an abundant and widely distributed chemical element, which combines with most of the other elements to form oxides and is essential to animal and plant life. 2. The molecular form of oxygen, O₂. 3. A medicinal gas that contains not less than 99.0%, by volume, of O₂. [G. oxys, sharp, acid, + genes, forming]

oxygen

A colourless, odourless gas, essential for life, that constitutes about one fifth of the earth's atmosphere. Oxygen is required for the functioning and survival of all body tissues, and deprivation for more than a few minutes is fatal. The respiratory system captures oxygen from the atmosphere and passes it to the blood by means of which it is conveyed to all parts of the body. Oxygen is needed for the fundamental chemical process of oxidation of fuel to release energy. This series of reactions is known as oxidative phosphorylation and involves the synthesis of the universal energy carrier ATP (ADENOSINE TRIPHOSPHATE) in the inner membranes of the MITOCHONDRIA of the cells. Oxygen is on the WHO official list.

oxygen

a colourless, tasteless gas forming about 21% of the earth's atmosphere, that is capable of combining with all other elements except the inert gases. Oxygen is particularly important in physical combustion processes and in AEROBIC RESPIRATION.

ox·y·gen

(ok'si-jĕn) Abundant and widely distributed gaseous chemical element, which combines with most other elements to form oxides and is essential to animal and plant life. [G. oxys, sharp, acid and genes, forming]

Patient discussion about oxygen

Q. hi my name is ray i am from england and i am on oxygen i am a retainer of carbon monxide do you guys know whoa any place working with stem cell or natural medicalemial rsantolla@aol.co.ukA. i had a whole course on stem cell use in tissue engineering and from what i know this is an area that still in research and very little clinical use. the ability to create lungs from Mesenchimal Stem Cells is a far away dream right now. but here are some links to labs that research that area:
http://organizedwisdom.com/Stem_Cells_for_Emphysema

Q. HONEY Use honey to seal MRSA (METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS) wound. A. honey has an antimicrobial activity due to it's acidity, osmotic power and hydrogen peroxide. about MRSA - there is a New Zealandic research about a type of honey that is effective against infections of MRSA. but it's only one research and another investigation is required.

More discussions about oxygen

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Properties and Compounds

Natural Occurrence and Preparation

Uses

Oxygen

REFERENCES

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Oxygen/Ozone Therapy

Definition

Purpose

Description

Origins

Hyperbaric oxygen therapy (hbo)

Ozone therapy

Hydrogen peroxide

Preparations

Precautions

Side effects

Research and general acceptance

Key terms

Resources

Periodicals

Organizations

Other

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Patient discussion about oxygen

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Synonyms for oxygen

noun a nonmetallic bivalent element that is normally a colorless odorless tasteless nonflammable diatomic gas

Synonyms

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