|
IDLH
The term immediately dangerous to life or health (IDLH) is defined by the US National Institute for Occupational Safety and Health (NIOSH) as exposure to airborne contaminants that is "likely to cause death or immediate or delayed permanent adverse health effects or prevent escape from such an environment." Examples include smoke or other poisonous gases at sufficiently high concentrations. It is calculated using the Median lethal dose, LD50 or LC50. The Occupational Safety and Health Administration (OSHA) regulation (1910.134(b)) defines the term as "an atmosphere that poses an immediate threat to life, would cause irreversible adverse health effects, or would impair an individual's ability to escape from a dangerous atmosphere." IDLH values are often used to guide the selection of breathing apparatus that are made available to workers or firefighters in specific situations. The NIOSH definition does not include hypoxia (medical), oxygen deficiency (below 19.5 percent) although ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
:en:Acetylene Tetrabromide
Tetrabromoethane (TBE) is a halogenated hydrocarbon, chemical formula C2H2Br4. Although three bromine atoms may bind to one of the carbon atoms creating 1,1,1,2-tetrabromoethane this is not thermodynamically favorable, so in practice tetrabromoethane is equal to 1,1,2,2-tetrabromoethane, where each carbon atom binds two bromine atoms. Uses It has an unusually high density for an organic compound, near 3 g/mL, due largely to the four bromine atoms.Organic based heavy liquids heavyliquids.com TBE is a at , and is used to separate [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
:en:Ammonia
Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous waste, particularly among aquatic organisms, and it contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to 45% of the world's food and fertilizers. Around 70% of ammonia is used to make fertilisers in various forms and composition, such as urea and Diammonium phosphate. Ammonia in pure form is also applied directly into the soil. Ammonia, either directly or indirectly, is also a building block for the synthesis of many pharmaceutical products and is used in many commercial cleaning products. It is mainly collected by downward displacement of both air and water. Although common in nature—both terrestrially and in the outer planets of the Solar System—and in wide use, ammonia is both ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
:en:Aldrin
Aldrin is an organochlorine insecticide that was widely used until the 1990s, when it was banned in most countries. Aldrin is a member of the so-called "classic organochlorines" (COC) group of pesticides. COCs enjoyed a very sharp rise in popularity during and after The Second World War. Other noteworthy examples of COCs include DDT. After research showed that organochlorines can be highly toxic to the ecosystem through bioaccumulation, most were banned from use. It is a colourless solid. Before the ban, it was heavily used as a pesticide to treat seed and soil. Aldrin and related "cyclodiene" pesticides (a term for pesticides derived from Hexachlorocyclopentadiene) became notorious as persistent organic pollutants.Robert L. Metcalf "Insect Control" in Ullmann’s Encyclopedia of Industrial Chemistry" Wiley-VCH, Weinheim, 2002. Structure & Reactivity The structure formula of aldrin is C12H8Cl6. The molecule has a molecular weight of 364.896 g/mol. The melting point of al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
:en:Aniline
Aniline is an organic compound with the formula C6 H5 NH2. Consisting of a phenyl group attached to an amino group, aniline is the simplest aromatic amine. It is an industrially significant commodity chemical, as well as a versatile starting material for fine chemical synthesis. Its main use is in the manufacture of precursors to polyurethane, dyes, and other industrial chemicals. Like most volatile amines, it has the odor of rotten fish. It ignites readily, burning with a smoky flame characteristic of aromatic compounds. It is toxic to humans. Relative to benzene, it is electron-rich. It thus participates more rapidly in electrophilic aromatic substitution reactions. Likewise, it is also prone to oxidation: while freshly purified aniline is an almost colorless oil, exposure to air results in gradual darkening to yellow or red, due to the formation of strongly colored, oxidized impurities. Aniline can be diazotized to give a diazonium salt, which can then undergo vario ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
:en:Acetone
Acetone (2-propanone or dimethyl ketone), is an organic compound with the formula . It is the simplest and smallest ketone (). It is a colorless, highly volatile and flammable liquid with a characteristic pungent odour. Acetone is miscible with water and serves as an important organic solvent in its own right, in industry, home, and laboratory. About 6.7 million tonnes were produced worldwide in 2010, mainly for use as a solvent and production of methyl methacrylate (and from that PMMA) as well as bisphenol A.Acetone World Petrochemicals report, January 2010Stylianos Sifniades, Alan B. Levy, "Acetone" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005. It is a common building block in o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
:en:Acetaldehyde
Acetaldehyde (IUPAC systematic name ethanal) is an organic chemical compound with the formula CH3CHO, sometimes abbreviated by chemists as MeCHO (Me = methyl). It is a colorless liquid or gas, boiling near room temperature. It is one of the most important aldehydes, occurring widely in nature and being produced on a large scale in industry. Acetaldehyde occurs naturally in coffee, bread, and ripe fruit, and is produced by plants. It is also produced by the partial oxidation of ethanol by the liver enzyme alcohol dehydrogenase and is a contributing cause of hangover after alcohol consumption. Pathways of exposure include air, water, land, or groundwater, as well as drink and smoke. Consumption of disulfiram inhibits acetaldehyde dehydrogenase, the enzyme responsible for the metabolism of acetaldehyde, thereby causing it to build up in the body. The International Agency for Research on Cancer (IARC) has listed acetaldehyde as a Group 1 carcinogen. Acetaldehyde is "one of the mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
:en:Ammonium Sulfamate
Ammonium sulfamate (or ammonium sulphamate) is a white crystalline solid, readily soluble in water. It is commonly used as a broad spectrum herbicide, with additional uses as a compost accelerator, flame retardant and in industrial processes. Manufacture and distribution It is a salt formed from ammonia and sulfamic acid. Ammonium sulfamate is distributed under the following tradenames, which are principally herbicidal product names: Amicide, Amidosulfate, Ammate, Amcide, Ammate X-NI, AMS, Fyran 206k, Ikurin, Sulfamate, AMS and Root-Out. Uses Herbicide Ammonium sulfamate is considered to be particularly useful in controlling tough woody weeds, tree stumps and brambles. Ammonium sulfamate has been successfully used in several major UK projects by organisations like the British Trust for Conservation Volunteers, English Heritage, the National Trust, and various railway, canal and waterways authorities. Several years ago the Henry Doubleday Research Association (HDRA) (kno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
:en:Acrylonitrile
Acrylonitrile is an organic compound with the formula and the structure . It is a colorless, volatile liquid although commercial samples can be yellow due to impurities. It has a pungent odor of garlic or onions. In terms of its molecular structure, it consists of a vinyl group () linked to a nitrile (). It is an important monomer for the manufacture of useful plastics such as polyacrylonitrile. It is reactive and toxic at low doses. Acrylonitrile was first synthesized by the French chemist Charles Moureu (1863–1929) in 1893. Occurrence Acrylonitrile is not naturally formed on Earth. It has been detected at the sub-ppm level at industrial sites. It persists in the air for up to a week. It decomposes by reacting with oxygen and hydroxyl radical to form formyl cyanide and formaldehyde. Acrylonitrile is harmful to aquatic life. Acrylonitrile has been detected in the atmosphere of Titan, a moon of Saturn. Computer simulations suggest that on Titan conditions exist such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
:en:Acrolein
Acrolein (systematic name: propenal) is the simplest unsaturated aldehyde. It is a colorless liquid with a piercing, acrid smell. The smell of burnt fat (as when cooking oil is heated to its smoke point) is caused by glycerol in the burning fat breaking down into acrolein. It is produced industrially from propylene and mainly used as a biocide and a building block to other chemical compounds, such as the amino acid methionine. History Acrolein was first named and characterized as an aldehyde by the Swedish chemist Jöns Jacob Berzelius in 1839. He had been working with it as a thermal degradation product of glycerol, a material used in the manufacture of soap. The name is a contraction of ‘acrid’ (referring to its pungent smell) and ‘oleum’ (referring to its oil-like consistency). In the 20th century, acrolein became an important intermediate for the industrial production of acrylic acid and acrylic plastics. Production Acrolein is prepared industrially by oxidation of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
:en:Acetonitrile
Acetonitrile, often abbreviated MeCN (methyl cyanide), is the chemical compound with the formula and structure . This colourless liquid is the simplest organic nitrile (hydrogen cyanide is a simpler nitrile, but the cyanide anion is not classed as organic). It is produced mainly as a byproduct of acrylonitrile manufacture. It is used as a polar aprotic solvent in organic synthesis and in the purification of butadiene. The skeleton is linear with a short distance of 1.16 Å. Acetonitrile was first prepared in 1847 by the French chemist Jean-Baptiste Dumas. Applications Acetonitrile is used mainly as a solvent in the purification of butadiene in refineries. Specifically, acetonitrile is fed into the top of a distillation column filled with hydrocarbons including butadiene, and as the acetonitrile falls down through the column, it absorbs the butadiene which is then sent from the bottom of the tower to a second separating tower. Heat is then employed in the separa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
:en:p-Anisidine
''p''-Anisidine (or ''para''-anisidine) is an organic compound with the formula CH3OC6H4NH2. A white solid, commercial samples can appear grey-brown owing to air oxidation. It is one of three isomers of anisidine, methoxy-containing anilines. It is prepared by reduction of 4-nitroanisole. Anisidine value ''p''-Anisidine condenses readily with aldehydes and ketones to form Schiff bases, which absorb at 350 nm. This colorimetric reaction is used to test for the presence of oxidation products in fats and oils, an official method for detecting them by the American Oil Chemists' Society The American Oil Chemists' Society (AOCS) is an international professional organization based in Urbana, Illinois dedicated to providing the support network for those involved with the science and technology related to fats, oils, surfactants, an .... It is particularly good at detecting unsaturated aldehydes, which are the ones that are most likely to generate unacceptable flavors, making it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
:en:n-Amyl Acetate
Amyl acetate (pentyl acetate) is an organic compound and an ester with the chemical formula CH3COO H2sub>4CH3 and the molecular weight 130.19g/mol. It is colorless and has a scent similar to bananas and apples. The compound is the condensation product of acetic acid and 1-pentanol. However, esters formed from other pentanol isomers ( amyl alcohols), or mixtures of pentanols, are often referred to as amyl acetate. The symptoms of exposure to amyl acetate in humans are dermatitis, central nervous system depression, narcosis and irritation to the eyes and nose. Uses It is used as a flavoring agent, as a paint and lacquer solvent, and in the preparation of penicillin. It is an inactive ingredient in liquid bandages. It is used as a fuel in the Hefner lamp. See also *Isoamyl acetate Isoamyl acetate, also known as isopentyl acetate, is an organic compound that is the ester formed from isoamyl alcohol and acetic acid, with the molecular formula C7H14O2.It is a colorless ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
-3D-balls.png "Click for more on -> :en:Ammonia")
