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Ethanolamine, formally 2-aminoethanol, is a viscous, alkaline liquid with an unpleasant, ammonia-like odor. It is miscible in all proportions with water and several oxygenated organic solvents, including methanol, acetone, and glycerol. As the hazard information table shows, it is hazardous to humans and the environment.
In one of the earliest literature references to ethanolamine (1897), noted chemist Ludwig Knorr at the University of Jena (Germany) made the compound on a large scale by treating ethylene oxide with ammonia. The author cited work from as early as 1860 in which researchers made ethanolamine salts but could not isolate the free base. More recent ethanolamine research included synthesis from nitromethane and formaldehyde, but the prevailing manufacturing method still goes back to Knorr鈥檚 work.
Ethanolamine has several important industrial uses: as a 鈥渟crubber鈥� to remove carbon dioxide, hydrogen sulfide, and other acidic pollutants from waste gas streams; as a starting material for manufacturing surfactants, chelating agents, and even pharmaceuticals; as an agent for softening leather; and as an additive for controlling pH in industrial water streams.
What鈥檚 new with ethanolamine? As with several recent Molecules of the Week, it has been . V铆ctor M. Rivilla, Bel茅n Tercero, Sergio Mart铆n, and colleagues in Spain, Italy, Japan, Chile, and the United States identified ethanolamine in a molecular cloud in the interstellar medium, specifically in a complex in the Milky Way鈥檚 Galactic Center.
More than most molecules found in space, ethanolamine has particular relevance to possible origins of life on Earth. It is present in the water-soluble 鈥渉eads鈥� of phospholipids, which form all known cell membranes. And it could be a direct precursor of glycine, the simplest amino acid, which has been detected in the comet聽67P/Churyumov鈥揋erasimenko.
Rivilla et al. conclude that their results 鈥渋ndicate that ethanolamine forms efficiently in space and, if delivered onto early Earth, could have contributed to the assembling and early evolution of primitive membranes.鈥�
Ethanolamine hazard information
Hazard class* | Hazard statement | |
---|---|---|
Flammable liquids, category 4 | H227鈥擟ombustible liquid | |
Acute toxicity, oral, category 4 | H302鈥擧armful if swallowed | ![]() |
Acute toxicity, dermal, category 4 | H312鈥擧armful聽 in contact with skin | ![]() |
Skin corrosion/irritation, category 1B | H314鈥擟auses severe skin burns and eye damage | ![]() |
Serious eye damage/eye irritation, category 1 | H318鈥擟auses serious eye damage | ![]() |
Acute toxicity, inhalation, category 4 | H332鈥擧armful if inhaled | ![]() |
Specific target organ toxicity, single exposure, respiratory tract irritation, category 3 | H335鈥擬ay cause respiratory irritation | ![]() |
Short-term (acute) aquatic hazard, category 2 | H401鈥擳oxic to aquatic life | ![]() |
Long-term (chronic) aquatic hazard, category 3 | H412鈥擧armful to aquatic life with long-lasting聽 effects | ![]() |
*Globally Harmonized System of Classification and Labeling of Chemicals.聽聽
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Ethanolamine fast facts
CAS Reg. No. | 141-43-5 |
nomenclature | Ethanol, 2-amino- |
Empirical formula | C2H7NO3 |
Molar mass | 61.08 g/mol |
Appearance | Viscous colorless liquid |
Melting point | 10.5 掳C |
Boiling point | 171 掳C |
Water solubility | Miscible |

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