Chemical Properties
Colorless to yellow liquid
Uses
Used as buffer; removal of carbon dioxide and hydrogen sulfide from gas mixtures.
Definition
ChEBI: A member of the class of ethanolamines that is ethane with an amino substituent at C-1 and a hydroxy substituent at C-2, making it both a primary amine and a primary alcohol.
General Description
A clear colorless liquid with an odor resembling that of ammonia. Flash point 185°F. May attack copper, brass, and rubber. Corrosive to tissue. Moderately toxic. Produces toxic oxides of nitrogen during combustion.
Reactivity Profile
ETHANOLAMINE(141-43-5) is a base. Reacts with organic acids (acetic acid, acrylic acid), inorganic acids (hydrochloric acid, hydrofluoric acid, nitric acid, sulfuric acid, chlorosulfonic acid), acetic anhydride, acrolein, acrylonitrile, cellulose, epichlorohydrin, mesityl oxide, beta-propiolactone, vinyl acetate. Emits toxic fumes of nitrogen oxides when heated to decomposition [Sax, 9th ed., 1996, p. 1498].
Air & Water Reactions
Water soluble with evolution of heat.
Health Hazard
Vapor irritates eyes and nose. Liquid causes local injury to mouth, throat, digestive tract, skin, and eyes.
Potential Exposure
Monoethanolamine is widely used in
industry for scrubbing acid gases and in production of
detergents and alkanolamide surfactants; to remove carbon dioxide and hydrogen from natural gas, to remove hydrogen
sulfide and carbonyl sulfide; as an alkaline conditioning
agent; as an intermediate for soaps, detergents, dyes, and
textile agents. Diethanolamine is an absorbent for gases; a
solubilizer for 2,4- dichlorophenoxyacetic acid (2,4-D); and
a softener and emulsifier intermediate for detergents. It also
finds use in the dye and textile industry. Triethanolamine is
used as plasticizers, neutralizer for alkaline dispersions;
lubricant additive; corrosion inhibitor; and in the manufacture of soaps, detergents, shampoos, shaving preparations;
face and hand creams; cements, cutting oils, insecticides,
surface active agents; waxes, polishes, and herbicides.
Fire Hazard
Special Hazards of Combustion Products: Irritating vapors generated when heated.
First aid
If this chemical gets into the eyes, remove any
contact lenses at once and irrigate immediately for at least
15 minutes, occasionally lifting upper and lower lids. Seek
medical attention immediately. If this chemical contacts the
skin, remove contaminated clothing and wash immediately
with soap and water. Speed in removing material from skin
is of extreme importance. Shampoo hair promptly if contaminated. Seek medical attention immediately. If this
chemical has been inhaled, remove from exposure, begin
rescue breathing (using universal precautions, including
resuscitation mask) if breathing has stopped and CPR if
heart action has stopped. Transfer promptly to a medical
facility. When this chemical has been swallowed, get medical attention. Give large quantities of water and induce
vomiting. Do not make an unconscious person vomit
Shipping
UN2491 Ethanol
amine or Ethanolamine solutions, Hazard class: 8; Labels: 8-Corrosive material.
Incompatibilities
Monoethanolamine: This chemical is a
medium-strong base. Reacts violently with strong oxidizers,
acetic acid; acetic anhydride; acrolein, acrylic acid; acrylonitrile, cellulose nitrate; chlorosulfonic acid; epichlorohydrin, hydrochloric acid; hydrogen fluoride; mesityl oxide;
nitric acid; oleum, sulfuric acid; β-propiolactone; and vinyl
acetate. Reacts with iron. May attack copper, aluminum,
and their alloys, and rubber. Di-isomer: Oxidizers, strong
acids; acid anhydrides; halides. Reacts with CO2 in the air.
Hygroscopic (i.e., absorbs moisture from the air). Corrosive
to copper, zinc, and galvanized iron (di-). The aqueous
solution is a medium strong base. Attacks copper, zinc,
aluminum, and their alloys.
Waste Disposal
Controlled incineration; incinerator equipped with a scrubber or thermal unit to reduce
nitrogen oxides emissions
Production Methods
Monoethanolamine is prepared commercially by the ammonolysis
of ethylene oxide. The reaction yields a mixture of monoethanolamine,
diethanolamine, and triethanolamine, which is separated to
obtain the pure products. Monoethanolamine is also produced from
the reaction between nitromethane and formaldehyde.
Flammability and Explosibility
Nonflammable
Pharmaceutical Applications
Monoethanolamine is used primarily in pharmaceutical formulations
for buffering purposes and in the preparation of emulsions.
Other uses include as a solvent for fats and oils and as a stabilizing
agent in an injectable dextrose solution of phenytoin sodium.
Monoethanolamine is also used to produce a variety of salts with
therapeutic uses. For example, a salt of monoethanolamine with
vitamin C is used for intramuscular injection, while the salicylate
and undecenoate monoethanolamine salts are utilized respectively
in the treatment of rheumatism and as an antifungal agent.
However, the most common therapeutic use of monoethanolamine
is in the production of ethanolamine oleate injection, which is used
as a sclerosing agent.
Safety
Monoethanolamine is an irritant, caustic material, but when it is
used in neutralized parenteral and topical pharmaceutical formulations
it is not usually associated with adverse effects, although
hypersensitivity reactions have been reported. Monoethanolamine
salts are generally regarded as being less toxic than monoethanolamine.
LD50 (mouse, IP): 0.05 g/kg
LD50 (mouse, oral): 0.7 g/kg
LD50 (rabbit, skin): 1.0 g/kg
LD50 (rat, IM): 1.75 g/kg
LD50 (rat, IP): 0.07 g/kg
LD50 (rat, IV): 0.23 g/kg
LD50 (rat, oral): 1.72 g/kg
LD50 (rat, SC): 1.5 g/kg
Environmental Fate
Biological. Bridié et al. (1979) reported BOD and COD values of 0.93 and 1.28 g/g using
filtered effluent from a biological sanitary waste treatment plant. These values were determined
using a standard dilution method at 20 °C for a period of 5 d. Similarly, Heukelekian and Rand
(1955) reported a 5-d BOD value of 0.85 g/g which is 65.0% of the ThOD value of 1.31 g/g.
Chemical/Physical. Aqueous chlorination of ethanolamine at high pH produced Nchloroethanolamine,
which slowly degraded to unidentified products (Antelo et al., 1981).
At an influent concentration of 1,012 mg/L, treatment with GAC resulted in an effluent
concentration of 939 mg/L. The adsorbability of the carbon used was 15 mg/g carbon (Guisti et
al., 1974).
Metabolism
Animal
Ethanolamine is a naturally occurring constituent in mammalian urine; the excretion
rate is about 1.36 mg/kg/d for rats, 0.91 mg/kg/d for rabbits, and 0.454
mg/kg/d for cats (Luck and Wilcox 1953). It was suggested that deamination of
ethanolamine occurs in vivo, since within 24 h after administration of [15N]-ethanolamine
to rabbits, 40% of the [15N]-label was excreted as urea (Beard and Noe
1981). Sprinson and Weliky (1969) found that labeled ethanolamine was extensively
converted to labeled acetate in rats.
Eight h after intraperitoneal injection of 0.52μmoles of [14C]-ethanolamine in
Wistar rats, 11.5% of the injected dose was recovered as 14C02 (Taylor and
Richardson 1967). At that time, about 50% of the injected radioactivity was found
in the liver, and significant amounts (>2% [14C]/g tissue) were detected in the
spleen and brain. In the liver, greater than 90% of the radioactivity was found in
the lipid fraction; in the kidney, spleen and brain, the per cent in the lipid fraction
was about 60, 30, and 54%, respectively. It was suggested that the main metabolic
pathway for ethanolamine in rats involves its incorporation into phospholipids,
presumably via exchange with serine in phosphatidylserine, resulting in the
formation of phosphatidylethanolamine. The incorporation of [14C]-ethanolamine
into ethanolamine phosphoglycerides in liver, heart and brain has been extensively
studied and is thought to occur via the CDP-ethanolamine pathway or by a base
exchange reaction (Ansell and Spanner 1967; Weinhold and Sanders 1971;
Zelinski and Choy 1982).
Fifty h after topical application of [14C]-ethanolamine to excised pig skin in
vitro (4μg/cm2), greater than 60% of the applied dose was found associated with
the skin (Klain et al 1985). Twenty-four h after dermal application of [14C]-
ethanolamine to athymic nude mice (4μg to 1.45 cm2), 19% of the applied dose
was recovered in expired C02; this value was similar to that obtained after ip
injection of ethanolamine. Radioactivity from [14C]ethanolamine was widely
distributed in the body, with the highest levels found in the liver (26%) and
kidneys (2.2%). Radioactivity was observed in hepatic phospholipids as the
ethanolamine, serine, and choline bases, and in proteins and amino acids isolated
from liver and skin sections. Urinary excretion included radioactive ethanolamine,
urea, glycine, serine, uric acid, and choline. Thus, ethanolamine penetrates mouse
skin and may be oxidized to C02, incorporated into hepatic phospholipids, or
metabolized to amino acids.
Twenty-four h after administration of [14C]-ethanolamine to dogs, total radioactivity
in the blood was 1.69% of the administered dse (Rhodes and Case 1977). Eleven % of the dose was excreted in the urine. The half-life of the persistent low
level of radioactivity in the blood was 19 d.
Human
Ethanolamine is a naturally occurring constituent in human urine, with a mean
excretion rate in males of 0.162 mg/kg/d and in females of 0.491 mg/kg/d (Luck
and Wilcox 1953). [14C]-ethanolamine was topically applied to human skin
grafted onto athymic nude mice at a dose of 4μg to a 1.45 cm2 graft area (Klain et
al 1985). The rate and amount of radioactivity expired as 14C02 was similar to that
described above for mice. Thus, the penetration rates of ethanolamine in human
skin grafts and mouse skin appear to be similar.
storage
Monoethanolamine is very hygroscopic and is unstable when
exposed to light. Aqueous monoethanolamine solutions may be
sterilized by autoclaving.
When monoethanolamine is stored in large quantities, stainless
steel is preferable for long-term storage. Copper, copper alloys, zinc,
and galvanized iron are corroded by amines and should not be used
for construction of storage containers. Ethanolamines readily
absorb moisture and carbon dioxide from the air; they also react
with carbon dioxide. This can be prevented by sealing the
monoethanolamine under an inert gas. Smaller quantities of
monoethanolamine should be stored in an airtight container,
protected from light, in a cool, dry place.
Regulatory Status
Included in parenteral and nonparenteral medicines licensed in the
UK and USA. Included in the Canadian List of Acceptable Nonmedicinal
Ingredients.
