ethanolamine ethanolamine ethanolamine (2-aminoethanol, monoethanolamine, eta, or mea) is an organic chemical compound with the formula hoch2ch2nh2 or c2h7no. the molecule is bifunctional, containing both a primary amine and a primary alcohol. ethanolamine is a colorless, viscous liquid with an odor reminiscent of ammonia. eta molecules are a component in the formation of cellular membranes and are thus a molecular building block for life. it was thought to exist only on earth and on certain asteroids, but in 2021 evidence was found that eta molecules exist in interstellar space. ethanolamine names preferred iupac name 2-aminoethan-1-ol other names 2-aminoethanol2-amino-1-ethanolethanolamine (not recommended)monoethanolamineβ-aminoethanolβ-hydroxyethylamineβ-aminoethyl alcoholglycinololaminemeaethylolamine2-hydroxyethylaminecolamine identifiers cas number 141-43-5 y 3d model (jsmol) interactive image chebi chebi:16000 y chembl chembl104943 y chemspider 13835336 y drugbank db03994 y echa infocard 100.004.986 ec number 205-483-3 kegg d05074 y pubchem cid 700 rtecs number kj5775000 unii 5kv86114pt y comptox dashboard (epa) dtxsid6022000 inchi inchi=1s/c2h7no/c3-1-2-4/h4h,1-3h2 ykey: hzaxfhjvjlsvmw-uhfffaoysa-n yinchi=1/c2h7no/c3-1-2-4/h4h,1-3h2key: hzaxfhjvjlsvmw-uhfffaoyad smiles ncco properties chemical formula c2h7no molar mass 61.084 g·mol−1 appearance viscous colourless liquid odor unpleasant ammonia-like odour density 1.0117 g/cm3 melting point 10.3 °c (50.5 °f; 283.4 k) boiling point 170 °c (338 °f; 443 k) solubility in water miscible vapor pressure 64 pa (20 °c) acidity (pka) 9.50 refractive index (nd) 1.4539 (20 °c) hazards ghs labelling: pictograms signal word danger hazard statements h302, h312, h314, h332, h335, h412 precautionary statements p261, p273, p303+p361+p353, p305+p351+p338 nfpa 704 (fire diamond) 3 2 0 flash point 85 °c (185 °f; 358 k) (closed cup) autoignitiontemperature 410 °c (770 °f; 683 k) explosive limits 5.5–17% lethal dose or concentration (ld, lc): ld50 (median dose) 3320 mg/kg (rat, oral)620 mg/kg (guinea pig, oral)2050 mg/kg (rat, oral)1475 mg/kg (mouse, oral)1000 mg/kg (rabbit, oral)700 mg/kg (mouse, oral)1720–1970 mg/kg (rat, oral) niosh (us health exposure limits): pel (permissible) twa: 3 ppm (6 mg/m3) rel (recommended) twa: 3 ppm (8 mg/m3)st: 6 ppm (15 mg/m3) idlh (immediate danger) 30 ppm safety data sheet (sds) sigma related compounds related compounds n-methylethanolaminediethanolaminetriethanolamine except where otherwise noted, data are given for materials in their standard state (at 25 °c , 100 kpa). y verify (what is yn ?) infobox references derivatives of ethanolamine are widespread in nature; e.g., lipids, as precursor of a variety of n-acylethanolamines (naes), that modulate several animal and plant physiological processes such as seed germination, plant–pathogen interactions, chloroplast development and flowering, as well as precursor, combined with arachidonic acid c20h32o2 20:4, ω-6), to form the endocannabinoid anandamide (aea: c22h37no2; 20:4, ω-6). the ethanolamines comprise a group of amino alcohols. a class of antihistamines is identified as ethanolamines, which includes carbinoxamine, clemastine, dimenhydrinate, chlorphenoxamine, diphenhydramine and doxylamine. industrial production monoethanolamine is produced by treating ethylene oxide with aqueous ammonia; the reaction also produces diethanolamine and triethanolamine. the ratio of the products can be controlled by the stoichiometry of the reactants. biochemistry ethanolamine is biosynthesized by decarboxylation of serine: hoch2ch(co2h)nh2 → hoch2ch2nh2 + co2 ethanolamine is the second-most-abundant head group for phospholipids, substances found in biological membranes (particularly those of prokaryotes); e.g., phosphatidylethanolamine. it is also used in messenger molecules such as palmitoylethanolamide, which has an effect on cb1 receptors. applications ethanolamine is commonly called monoethanolamine or mea in order to be distinguished from diethanolamine (dea) and triethanolamine (tea). it is used as feedstock in the production of detergents, emulsifiers, polishes, pharmaceuticals, corrosion inhibitors, and chemical intermediates. for example, reacting ethanolamine with ammonia gives ethylenediamine, a precursor of the commonly used chelating agent, edta. gas stream scrubbing monoethanolamines can scrub combusted-coal, combusted-methane and combusted-biogas flue emissions of carbon dioxide (co2) very efficiently. mea carbon dioxide scrubbing is also used to regenerate the air on submarines. solutions of mea in water are used as a gas stream scrubbing liquid in amine treaters. for example, aqueous mea is used to remove carbon dioxide (co2) and hydrogen sulfide (h2s) from various gas streams; e.g., flue gas and sour natural gas. the mea ionizes dissolved acidic compounds, making them polar and considerably more soluble. mea scrubbing solutions can be recycled through a regeneration unit. when heated, mea, being a rather weak base, will release dissolved h2s or co2 gas resulting in a pure mea solution. other uses in pharmaceutical formulations, mea is used primarily for buffering or preparation of emulsions. mea can be used as ph regulator in cosmetics. it is an injectable sclerosant as a treatment option of symptomatic hemorrhoids. 2–5 ml of ethanolamine oleate can be injected into the mucosa just above the hemorrhoids to cause ulceration and mucosal fixation thus preventing hemorrhoids from descending out of the anal canal. it is also an ingredient in cleaning fluid for automobile windshields. ph-control amine ethanolamine is often used for alkalinization of water in steam cycles of power plants, including nuclear power plants with pressurized water reactors. this alkalinization is performed to control corrosion of metal components. eta (or sometimes a similar organic amine; e.g., morpholine) is selected because it does not accumulate in steam generators (boilers) and crevices due to its volatility, but rather distributes relatively uniformly throughout the entire steam cycle. in such application, eta is a key ingredient of so-called "all-volatile treatment" of water (avt). reactions upon reaction with carbon dioxide, 2 equivalents of ethanolamine react through the intermediacy of carbonic acid to form a carbamate salt, which when heated reforms ethanolamine and carbon dioxide.