Major Gases

While there are literally thousands of available industrial gases, certain industrial gases are major elements of the world economy. Major gases include:

• Hydrogen (H) - a colorless, highly flammable, gaseous element.  It is used in the production of synthetic ammonia and methanol, in petroleum refining, in the hydrogenation of organic materials, as a reducing atmosphere, in oxyhydrogen torches, and in rocket fuels. Ordinary hydrogen gas is made of diatomic molecules (H2) that react with oxygen to form water (H2O) and hydrogen peroxide (H2O2), usually as a result of combustion.

• Hydrogen Bromide - an irritating, colorless gas used in the manufacture of barbiturates and synthetic hormones.

• Hydrogen Chloride (HCl) - a highly corrosive and toxic, colorless gas. White fumes form on contact with humidity. HCl often refers to hydrochloric acid, which is actually a mixture of hydrogen chloride in water.

• Hydrogen Fluoride (HF) - a colorless, fuming, corrosive liquid or a highly soluble, corrosive gas used in the manufacture of hydrofluoric acid; as a reagent, catalyst, and fluorinating agent; and in the refining of uranium and the preparation of many fluorine compounds.
• Hydrogen Sulfide (H2Se) - a colorless, flammable, poisonous gas with a characteristic rotten-egg odor. It is used as an antiseptic, bleach, or reagent.

• Nitrogen - a nonmetallic element that constitutes nearly four-fifths of the air by volume. It occurs as a colorless, odorless, almost inert, diatomic gas (N2), in various minerals. Nitrogen is found in all proteins and used in a wide variety of important manufactures, including ammonia, nitric acid, TNT, and fertilizers. Atomic number 7; atomic weight 14.0067; melting point -209.86°C; boiling point -195.8°C; valence 3, 5.

• Ammonia (NH3) - toxic and corrosive to some materials; with a pungent odor. Ammonia is used in the production of fertilizers, explosives, polymers, and household cleaners.

• Nitric Oxide (NO) - a toxic air pollutant produced by automobiles and power plants.

• Nitrous Oxide -include dinitrogen oxide (N2O, nitrous oxide), dinitrogen trioxide (N2O3), dinitrogen tetroxide (N2O4), and dinitrogen pentoxide (N2O5).
• Nitrogen Dioxide (NO2) - a poisonous brown gas often found in smog and automobile exhaust fumes. It is synthesized for use as a nitrating agent, a catalyst, and an oxidizing agent.
• Nitrogen Trifluoride (NF3) - a colorless gas that has a melting point of -206.6°C and a boiling point of -128.8°C; used as an oxidizer for high-energy fuels.

• Air - a colorless, odorless, tasteless, gaseous mixture; mainly nitrogen (approximately 78 percent) and oxygen (approximately 21 percent), with lesser amounts of argon, carbon dioxide, hydrogen, neon, helium, and other gases.

• Oxygen (O2) - an atmospheric gas. The abundance of free oxygen is due to photosynthesis by plants.

• Carbon Dioxide (CO2) - a common chemical compound formed as a byproduct of respiration, fire, and combustion.

• Carbon Monoxide (CO) - a flammable, toxic, colorless, and odorless. It is also a major byproduct of combustion.
• Ethylene Oxide (CH2)2O - a colorless gas, soluble in organic solvents and miscible in water; boiling point 11°C; used in organic synthesis for sterilizing, and fumigating. Also known as 1,2-epoxyethane epoxide; oxiranet.
• Sulfur Dioxide - sulfur dioxide (SO2) is a colorless, extremely irritating gas or liquid used in many industrial processes, especially the manufacture of sulfuric acid.

• Argon - one of the inert or noble gases. Argon gas is colorless, odorless, nontoxic, and nonflammable. Argon is typically shipped as a compressed gas.

• Helium - a colorless, odorless, inert, gaseous element occurring in natural gas and with radioactive ores. It is used as a component of artificial atmospheres and laser media, as a refrigerant, as a lifting gas for balloons, and as a superfluid in cryogenic research. Atomic number 2; atomic weight 4.0026; boiling point -268.9°C; density at 0°C 0.1785 gram per liter.
• Krypton -  a whitish, largely inert, gaseous element used chiefly in gas discharge lamps and fluorescent lamps. Atomic number 36; atomic weight 83.80; melting point -156.6°C; boiling point -152.30°C; density 3.73 grams per liter (0°C).
• Neon -  a whitish, largely inert, gaseous element used chiefly in gas discharge lamps and fluorescent lamps. Atomic number 36; atomic weight 83.80; melting point -156.6°C; boiling point -152.30°C; density 3.73 grams per liter (0°C).

• Xenon - a colorless, odorless, highly unreactive, gaseous element found in minute quantities in the atmosphere, extracted commercially from liquefied air and used in stroboscopic, bactericidal, and laser-pumping lamps. Atomic number 54; atomic weight 131.29; melting point -111.9°C; boiling point -107.1°C; density (gas) 5.887 grams per liter; specific gravity (liquid) 3.52 (-109°C).

• Acetylene - a colorless, highly flammable or explosive gas; C2H2 is used for metal welding and cutting and as an illuminant. Also called ethyne.

• Butane - two isomers of a gaseous hydrocarbon; C4H10 is produced synthetically from petroleum and is used as a household fuel, refrigerant, and aerosol propellant, and in the manufacture of synthetic rubber.
• Butadiene - a colorless, highly flammable hydrocarbon, C4H6 is obtained from petroleum and used in the manufacture of synthetic rubber.
• Butene - any of three isomeric hydrocarbons C4H8; all used in making synthetic rubbers; also known as butylene.
• Ethane - a colorless, odorless, gaseous alkane; C2H6 occurs as a constituent of natural gas and is used as a fuel and a refrigerant.
• Ethylene - A colorless flammable gas; C2H4 is derived from natural gas and petroleum, and is used as a source of many organic compounds: in welding and cutting metals, to coloring citrus fruits, and as an anesthetic. Also called ethene.
• Methane - an odorless, colorless, flammable gas; CH4, the major constituent of natural gas, is used as a fuel, and is an important source of hydrogen and a wide variety of organic compounds.
• Butadiene - a colorless, highly flammable hydrocarbon, C4H6 is obtained from petroleum and used in the manufacture of synthetic rubber.
• Propane - A colorless gas, C3H8 is found in natural gas and petroleum, and is widely used as a fuel.
• Propylene - a flammable gas, CH3CH:CH2 is derived from petroleum hydrocarbon cracking and used in organic synthesis. Also called propene..

• Chlorine (Cl2) - a diatomic gas that is yellow-green in color. It is a halogen that combines easily with nearly all other elements. Chlorine irritates the respiratory system and mucous membranes. It is fatal in amounts of 1,000 ppm or more. Prolonged exposures at lower, non-fatal levels weaken the lungs..

•  Boron Trichloride - A flammable gas, CH3CH:CH2 is derived from petroleum hydrocarbon cracking and used in organic synthesis. Also called propene.
• Chlorine Trifluoride (ClF3) - a colorless, poisonous, corrosive, and very reactive gas that condenses to a pale, greenish-yellow liquid -- the form in which it is most often sold (pressurized at room temperature). The compound is primarily of interest as a component in rocket fuels, in industrial cleaning and etching operations in the semiconductor industry, in nuclear reactor fuel processing, and other industrial operations
•  Dichlorosilane (H2SiCl2) - or DCS as it is commonly known, is usually mixed with ammonia (NH3) in LPCVD chambers to grow silicon nitride in semiconductor processing.
• Ethyl Chloride (C2H5Cl) - a gas at ordinary temperatures and a colorless, volatile, flammable liquid when compressed; used as a solvent, as a refrigerant, and in the manufacture of tetraethyl lead..
• Silicon Tetrachloride (C2H5Cl) - a gas at ordinary temperatures and a colorless, volatile, flammable liquid when compressed; used as a solvent, as a refrigerant, and in the manufacture of tetraethyl lead
• Trichlorosilane - a chemical compound containing silicon, hydrogen, and chlorine. At high temperatures it decomposes to produce silicon, and therefore purified trichlorosilane is the principal source of ultrapure silicon in the semiconductor industry. In water, it rapidly decomposes to produce a silicone polymer while giving off hydrochloric acid. Because of its reactivity and wide availability it is frequently used in the synthesis of silicon-containing organic compounds..
• Fluorine (F) - a poisonous, pale, yellow-green gas that is the most chemically reactive of all the elements. It is highly dangerous in its pure form and can cause severe burns if it comes into contact with the skin..
• Boron Trifluoride (BF3) - a pungent, colorless toxic gas that forms white fumes in moist air. It is a useful Lewis acid and a versatile building block for other boron compounds.
• Sulfur Hexafluoride (SF6) - one of the most popular insulating gases (next to air). It is non-flammable, non-toxic, moderately inexpensive, and a good insulator because of its electronegativity. SF6 has a breakdown strength of about three times that of air. At normal temperatures it is non-corrosive and fairly inert; however, at temperatures above 500°C SF6 decomposes. The decomposition products (i.e., fluorine) react with most substances, especially any water vapor.
• Tungsten Hexafluoride - an inorganic compound with the formula WF6. This corrosive, colorless compound is the densest known gas at a pressure of 1 atm and room temperature (25 °C). The gas is most commonly used in the production of semiconductor circuits and circuit boards through the process of chemical vapor deposition.