Ethanolamine Ethanolamine Chemical name 2-aminoethanol Other names ethanolamine , monoethanolamine Chemical formula C 2 H 7 NO Molecular mass 61.08 g/mol CAS number [ 141-43-5 ] Density 1.012 g/cm 3 Melting point 10.3 °C Boiling point 170 °C SMILES NCCO Disclaimer and references Ethanolamine , also called 2-aminoethanol or monoethanolamine ( often abbreviated as MEA ) , is an organic chemical compound which is both a primary amine ( due to an amino group in its molecule ) and a primary alcohol ( due to a hydroxyl group ) . Like other amines , monoethanolamine acts as a weak base . Ethanolamine is a toxic flammable corrosive colorless viscous liquid with an odor similar to ammonia . Ethanolamine is commonly called monoethanolamine or MEA to distinguish it from diethanolamine ( DEA ) and triethanolamine ( TEA ) . Monoethanolamine is produced by reacting ethylene oxide with ammonia . Further treatment with ethylene oxide can yield DEA and/or TEA. Ethanolamine is the second most abundant head group for phospholipids . Ethanolamine also refers to a class of antihistamines containing an ethyl-amine group attached to a diphenyl structure . Examples of drugs within this class include diphenhydramine ( Benadryl ) , phenyltoloxamine ( Percogesic ) , and doxylamine ( Unisom Sleep Tablets ) . They are one of the oldest classes of antihistamine drugs , yet remain the most effective for treating allergy symptoms , even exceeding the effectiveness of new OTC and prescription antihistamines such as loratadine ( Claritin ) and Fexofenadine ( Allegra ) . However , all ethanolamines are extremely sedating , even more so than many barbiturates . For this reason , they are not always desirable drugs for treatment , and less-effective drugs are indicated to avoid the substantial drowsiness inherent in ethanolamines . On the other hand , they are such effective sedatives that they are marketed as over-the-counter sleep-aids in addition to anti-allergy medications . Uses of monoethanolamine ( MEA ) MEA is used in aqueous solutions for scrubbing certain acidic gases and is also used in surface active agents , emulsifiers , polishes , pharmaceuticals , corrosion inhibitors , chemical intermediates . In pharmaceutical formulations , MEA is primarily used for buffering or preparation of emulsions . Aqueous solutions of MEA ( 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 ( CO 2 ) from flue gas . Aqueous solutions can weakly dissolve certain kinds of gases from a mixed gas stream . The MEA in such solutions , acting as a weak base , then neutralizes acidic compounds dissolved in the solution to turn the molecules into an ionic form , making them polar and considerably more soluble in a cold MEA solution and thus keeping such acidic gases dissolved in this gas-scrubbing solution . Therefore , large surface area contact with such a cold scrubbing solution in a scrubber unit can selectively remove such acidic components as hydrogen sulfide ( H 2 S ) and CO 2 from some mixed gas streams . For example , basic solutions such as aqueous MEA or aqueous potassium carbonate can neutralize H 2 S into hydrosulfide ion ( HS - ) or CO 2 into bicarbonate ion ( HCO 3 - ) . H 2 S and CO 2 are only weakly acidic gases . An aqueous solution of a strong base such as sodium hydroxide ( NaOH ) will not readily release these gases once they have dissolved . However , MEA is rather weak base and will re-release H 2 S or CO 2 when the scrubbing solution is heated . Therefore , the MEA scrubbing solution is recycled through a regeneration unit which heats the MEA solution from the scrubber unit to release these only slightly acidic gases into a purer form and returns the regenerated MEA solution to the scrubber unit again for reuse . See also N -Methylethanolamine External links Link page to external chemical sources . Categories : Alcohols | Amines In other languages : Deutsch | Polski | Русский 