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Ethyl carbamate (also called urethane) is a substance first prepared in the nineteenth century. Structurally it is an ester of carbamic acid, i. e., ethyl carbamate as shown. Urethane itself is: (NH2-COOC2H5) and is not a component of polyurethanes. Image File history File links Download high resolution version (2000x3231, 52 KB) Description: chemical structure of urethane Source/Drawer: Self made, 13:23, 31 May 2005 (UTC) License: GNU FDL --Rhododendronbusch 13:23, 31 May 2005 (UTC) (Picture is optimized for printable medias, so its width/resolution is ≥ 2000 pixel...
IUPAC nomenclature is a system of naming chemical compounds and of describing the science of chemistry in general. ...
A chemical formula (also called molecular formula) is a concise way of expressing information about the atoms that constitute a particular chemical compound. ...
The molecular mass (abbreviated MM) of a substance, called molecular weight and abbreviated as MW, is the mass of one molecule of that substance, relative to the unified atomic mass unit u (equal to 1/12 the mass of one atom of carbon-12). ...
CAS registry numbers are unique numerical identifiers for chemical compounds, polymers, biological sequences, mixtures and alloys. ...
Density (symbol: Ï - Greek: rho) is a measure of mass per unit of volume. ...
The melting point of a solid is the temperature at which it changes state from solid to liquid. ...
The boiling point of a substance is the temperature at which it can change its state from a liquid to a gas throughout the bulk of the liquid at a given pressure. ...
The simplified molecular input line entry specification or SMILES is a specification for unambiguously describing the structure of chemical molecules using short ASCII strings. ...
Carbamates are a group of organic compounds sharing a common functional group with the general structure -NH(CO)O-. More precisely the carbamate group is considered an amide group with an alkoxy or hydroxy functional group next to the carbonyl group. ...
General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless Atomic mass 14. ...
General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ...
General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Atomic mass 12. ...
General Name, Symbol, Number oxygen, O, 8 Chemical series Nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless Atomic mass 15. ...
A polyurethane is any polymer consisting of a chain of organic units joined by urethane links. ...
Synthesis This ethyl ester is a white crystalline substance produced by the action of ammonia on ethyl carbonate or by heating urea nitrate and ethyl alcohol (Merck 1989). Ammonia is a compound of nitrogen and hydrogen with the formula NH3. ...
Ethyl alcohol, also known as ethanol or grain alcohol, is a flammable, colorless chemical compound, one of the alcohols that is most often found in alcoholic beverages. ...
Other carbamates include methyl carbamate (urethylane, m. p. 52-54°C)(HSDB 2006b), butyl carbamate(HSDB 2006c), and phenyl carbamate (m. p. 149-152°C) (Dean 1985), which can also be prepared from the corresponding chloroformate and ammonia. Image File history File links Urethane_prep. ...
Methyl carbamate (also called methylurethane, or urethylane) is an organic compound and the simplest ester of the hypothetic carbamic acid (NH2COOH). ...
Properties These esters are white, crystalline solids at room temperature. Except for the phenyl carbamate, they sublime at moderate temperatures; methyl carbamate sublimes at room temperatures. The first two and urethane are very soluble in water, benzene, and ether (HSBD 2006a,b,c).
Uses In the past urethane has been produced commercially in the United States for over 30 years. It has been used as an antineoplastic agent and for other medicinal purposes. By US FDA regulations urethane has been withdrawn from pharmaceutical use. Formerly, cross linking agents for permanent press textile treatments were synthesized from urethane(NTP 2005). Although reports made to the USEPA for the Toxics Release Inventory indicate that over 100,000 pounds of urethane was used in 2004 (USEPA 2006); this is probably in error, because of incorrect reporting. Apparently, small quantities of this ester are used in laboratories as an anesthetic for animals (VCU 2006). The other carbamates (methyl, butyl, and phenyl) are only used in small quantities for research purposes. The Toxics Release Inventory (TRI) is a publicly available database from the EPA that contains information on toxic chemical releases and other waste management activities reported annually by certain covered industry groups as well as federal facilities. ...
Methyl carbamate (also called methylurethane, or urethylane) is an organic compound and the simplest ester of the hypothetic carbamic acid (NH2COOH). ...
Occurrence of Urethane in Beverages and Food After 1984 studies showed that various alcoholic beverages contained traces (15 ppb to 12 ppm) of urethane (Segal 1988). Later studies have shown that other foods and beverages that are prepared by fermentation processes also contain trace amounts of urethane. For example, bread has been found to contain 2 ppb (Haddon, et. al. 1994), while as much a 20 ppb has been found in some samples of soy sauce (Matsudo, et. al., 1993). It has been shown that urethane forms from the reaction of alcohol(ethanol) with urea. In chemistry, an alcohol is any organic compound in which a hydroxyl group (-OH) is bound to a carbon atom of an alkyl or substituted alkyl group. ...
Urea is an organic compound of carbon, nitrogen, oxygen and hydrogen, with the formula CON2H4 or (NH2)2CO. Urea is also known as carbamide, especially in the recommended International Non-proprietary Names (rINN) in use in Europe. ...
 Image File history File links EtOH_plus_urea. ...
This reaction is much faster at higher temperatures, and, therefore, higher concentrations of urethane are found in beverages that are heated in processing, such as desert wines, fruit brandies, and whiskey. The urea in wines results from the metabolism of arginine or citrulline by yeast or other organisms. Although this process can not be eliminated, it can be minimized by controlling fertilization of grape vines, minimizing heat exposure, and other actions (Butzke & Bisson 1997) Traces of methyl carbamate have also been found in wines. In 1988 wine and other alcoholic beverage manufacturers agreed to control the levels of urethane in wine to less than 15 ppb, and in stronger alcoholic drinks to less than 125 ppb (Segal 1988). Other countries have set limits on the concentration of urethane in alcoholic beverages (see the German record: Urethan). Arginine (Arg) is an α-amino acid. ...
The chemical compound citrulline is an α-amino acid (AA). ...
Methyl carbamate (also called methylurethane, or urethylane) is an organic compound and the simplest ester of the hypothetic carbamic acid (NH2COOH). ...
Hazards Urethane is not acutely toxic to humans, as shown by its use as a medicine. Acute toxicity studies show that the lowest fatal dose in rats, mice, and rabbits equals 1.2 grams/kg. or more. When urethane was used medicinally, about 50 percent of the patients exhibited nausea and vomiting, and long time use lead to gastroenteric hemorrhages(USEPA 1979). The compound has almost no odor and a cooling, saline, bitter taste (HSDB 2006a).
Studies with rats, mice, and hamsters has shown that urethane will cause cancer when it is administered orally, injected, or applied to the skin, but no adequate studies of urethane-caused cancer in humans has been reported (IARC,1974). The International Agency for Research on Cancer has stated that urethane can be “reasonably anticipated to be a human carcinogen based on sufficient evidence of carcinogenicity in experimental animals.” (NTP 2005). This evaluation has lead to the following US regulatory actions:
NESHAP: Listed as a Hazardous Air Pollutant (HAP) Comprehensive Environmental Response, Compensation, and Liability Act Reportable Quantity (RQ) = 100 lb The National Emissions Standards for Hazardous Air Pollutants (NESHAPS) are emissions standards set by the United States EPA for an air pollutant not covered by NAAQS that may cause an increase in fatalities or in serious, irreversible, or incapacitating illness. ...
Emergency Planning and Community Right-To-Know Act EPA’s Toxics Release Inventory A listed substance subject to RCRA reporting requirements RCRA Listed Hazardous Waste: substance - U238
References Butzke, C E & L F Bisson, “Ethyl Carbamate Preventative Action Manual” from Depart. of Viticulture & Enology, U. of CA, Davis, CA, for US FDA, 1997 accessed May 13, 2006 at http://www.cfsan.fda.gov/~frf/ecaction.html
Dean, JA (editor), Lange’s Handbook of Chemistry, 13th Ed., 1985, p. 7-586, #p191.
HSDB National Library of Medicine, Hazardous Data Bank, Ethyl Carbamate 2006a, accessed May 13, 2006 at http://toxnet.nlm.nih.gov/
Haddon W F, M I Mancini, M Mclaren, A Effio, L A Harden, R I Egre, & J L Bradford; Cereal Chemistry; 71 (2).. 207-215, 1994; accessed May 12, 2006 at http://toxnet.nlm.nih.gov
HSDB National Library of Medicine, Hazardous Data Bank, Methyl Carbamate 2006b, accessed May 13, 2006 at http://toxnet.nlm.nih.gov
HSDB National Library of Medicine, Hazardous Data Bank, Butyl Carbamate 2006c, accessed May 13, 2006 at http://toxnet.nlm.nih.gov
Matsudo T, T Aoki, K Abe, N Fukuta, T Higuchi, M Sasaki & K Uchida, J Agric Food Chem; 41 (3). 352-356(1993); accessed May 12, 2006 at http://toxnet.nlm.nih.gov
Merck S. Budavari (editor), The Merck Index, 11th Edition, no. 9789, 1989.
NTP National Toxicology Program, NIEHS, National Institutes of Health, “Eleventh Report on Carcinogens, Urethane”, 2005: accessed May 13,2006 at: http://ntp.niehs.nih.gov/ntp/roc/eleventh/profiles/s184uret.pdf
OTS EPA. Office of Toxic Substances, “Chemical Hazard Information Profile Urethane, CAS No. 51-79-6 , U.S. EPA, Washington, D.C., 12 pages, 26 references, 1979, accessed May 13, 2006 at http://toxnet.nlm.nih.gov
Segal, M “Too Many Drinks Spiked with Urethane” US Food and Drug Administration, September 1988, accessed at http://www.cfsan.fda.gov/~frf/fc0488ur.html.
USEPA Toxic Release Inventory, Urethane Data 2004 (released April 12, 2006).
VCU Virginia Commonwealth University, The Chemical/Biological Safety Section (CBSS) of the Office of Environmental Health and Safety, “Working with Urethane” 2006 accessed May 13,2006 at http://www.vcu.edu/oehs/chemical/biosafe/urethane.pdf.
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