Chemical Properties
Diethylamine is a colorless, strongly alkaline, highly inflammable, liquid. It is completely soluble
in water. On burning, diethylamine releases ammonia, carbon monoxide, carbon dioxide,
and nitrogen oxides. It is incompatible with several chemical substances, such as strong
oxidizers, acids, cellulose nitrate, some metals, and dicyanofuroxan. N-nitrosamines, many
of which are known to be potent carcinogens, may be formed when diethylamine comes in
contact with nitrous acid, nitrates, or atmospheres with high nitrous oxide concentrations. It
has several applications in industries, such as organic synthesis of resins, as rubber accelerator,
pharmaceuticals, pesticides, dyes, electroplating operations, and as a polymerization inhibitor.
General Description
A clear colorless liquid with an ammonia-like odor. Density 5.9 lb/gal. Flash point-15°F. A respiratory irritant. Corrosive to the eyes and skin. Vapors heavier than air. Toxic oxides of nitrogen produced during combustion.
Reactivity Profile
DIETHYLAMINE(109-89-7) is strongly alkaline. Incompatible with strong oxidizing agents and with strong acids. Violent reactions occur with sulfuric acid. Causes ignition on contact with cellulose nitrate. Explodes on contact with dicyanofurazan or dicyanofuroxan. Attacks some forms of plastics, rubber and coatings.
Air & Water Reactions
Highly flammable. Soluble in water. Sensitive to heat. May be sensitive to prolonged exposure to air.
Health Hazard
Exposures to diethylamine cause adverse health effects. The symptoms of toxicity include
irritation of skin, eyes, and mucous membrane. The acute oral LD50 and acute dermal LD50
in rats and rabbits are 540 and 580 mg/kg, respectively, and the acute inhalation LC50 (4
h) in rats is 4000 ppm. The pathomorphological changes caused by diethylamine include
lungs, liver, and kidneys, cellular infi ltration, bronchopneumonia, parenchymatous
degeneration, and nephritis.
Health Hazard
Irritation and burning of eyes, skin, and respiratory system. High concentration of vapor can cause asphyxiation.
Physical properties
Colorless liquid with a fishy, ammonia-like odor. Experimentally determined detection and recognition odor threshold concentrations were 60 μg/m3 (20 ppbv) and 180 μg/m3 (60 ppbv), respectively (Hellman and Small, 1974). Diethylamine is a very strong base in aqueous solution (pKb = 3.0). Its chemistry is governed by the unshared electron pair on the nitrogen, thus it tends to react with acids to form salts.
Occurrence
Diethylamine occurs in low concentrations in food and other biological materials.
Concentrations (in p.p.m.) in fresh products include: spinach (15), apples (3), butterbeans
(2.4), shelled peas (0.1), bean salad (1.5) and red cabbage (2.4) (HSDB
1989). Pickled vegetables contain 0-3.2 p.p.m. diethylamine while concentrations
(in p.p.m.) in other materials include herring (0-5.2), barley (5.7), hops (3.1), boiled
beef (2), tobacco leaf (0.1-35) and cigarette smoke concentrate (0-0.4). Interest in
the occurrence of diethylamine in foods arises in part because of its possible formation
of a carcinogenic N-nitroso derivative (Neurath et al 1977). Diethylamine has
been reported in the exhaust from a gasoline engine (Hampton et al 1982).
Uses
Diethylamine is manufactured by heating ethyl chloride and
alcoholic ammonia under pressure or by hydrogenation of
aziridines in the presence of catalysts. DEA is used as a
solvent, as a rubber accelerator, in the organic synthesis of
resins, dyes, pesticides, and pharmaceuticals, in electroplating,
and as a polymerization inhibitor. Other
applications include uses as a corrosion inhibitor. It was
reported noneffective as a skin depigmentator.
Uses
In flotation agents, resins, dyes, resins, pesticides, rubber chemicals, and pharmaceuticals;
selective solvent; polymerization and corrosion inhibitors; petroleum chemicals; electroplating;
organic synthesis.
Uses
In the rubber and petroleum industry;
in flotation agents; in resins, dyes,
pharmaceuticals
Definition
ChEBI: A secondary aliphatic amine where both N-substituents are ethyl.
Production Methods
Diethylamine is produced using the three methods also used for the manufacture of
ethylamine with very slight modification. The most widely used method is the
passing of ammonia and ethanol over a catalyst such as alumina or silica (Schweizer
et al 1978). Diethylamine can be separated from the mixture by selective
distillations and extractions. This secondary amine can also be produced by the
other two methods which involve: 1) passing ammonia, ethanol, and hydrogen
over a dehydrogenation catalyst; and 2) passing ammonia and an aldehyde or
ketone and hydrogen over a hydrogenation catalyst. U.S. production in 1984 is
estimated at 19.7 million pounds (HSDB 1989).
Flammability and Explosibility
Highlyflammable
Chemical Reactivity
Reactivity with Water No reaction; Reactivity with Common Materials: No hazardous reaction; Stability During Transport: Stable; Neutralizing Agents for Acids and Caustics: Flush with water; Polymerization: Not pertinent; Inhibitor of Polymerization: Not pertinent.
Industrial uses
Diethylamine, like many of the other short chain aliphatic amines, has achieved
widespread industrial use as an intermediate in the manufacture of a number of
commercial products. Among these are included insecticides, pharmaceuticals,
textile finishing agents, and corrosion inhibitors (Hawley 1981; Schweizer et al
1978). It is used as a polymerization inhibitor and/or catalyst in the polymer
industry and in the manufacture of surfactants and rubber processing accelerators.
This amine also is useful as a depilatory agent for animal skins, as a selective
solvent for the removal of impurities from oils, fats, and waxes, and as a flotation
agent in the petroleum industry (NIOSH/OSHA 1981; HSDB 1989).
Toxicology
Exposure to low vapor concentrations are reported to transiently impair vision in humans (reduction of sensitivity to light): no-effect threshold 0.022 – 0.028 mL/m3 ( 0.08mg/m3 ). The odor threshold in air is ca. 0.02 – 0.3 mL/m3 ( 0.9 mg/m3 ). Transient physiological effects in rats after 90-d exposure to vapors were reported to already be visible at 0.37 – 4.19 mg/m3 with no effects at 0.05 mg/m3 , but with morphological, apparently reversible changes in the lung and cerebral neurons at the highest concentration. On the other hand, 50 mL/m3 (150 mg/m3 ) was the lowest concentration to show mild, but signifi- cant effects in the lung and liver of rabbits on prolonged inhalation. There were no visible signs of toxicity following exposure of rats to 25 mL/m3 (75 mg/m3 ) for 120 d, but a moderate, bronchiolar hyperplasia of lymphoid cells. It was assumed that diethylamine may exert a certain neurotoxic effect, which, however, was not confirmed by others.
Potential Exposure
Tumorigen,Mutagen. Primary Irritant. Diethylamine (DEA) is used in themanufacture of the following chemicals: diethyldithiocarbamate and thiurams (rubber processing accelerators);diethylaminoethanol (medicinal intermediate); diethylaminopropylamine (epoxy curing agent); N,N-diethyl-m-toluamide and other pesticides; and 2-diethylaminoethylmethacrylate. Itis used in the manufacture of several drugs.
First aid
If this chemical gets into the eyes, remove anycontact lenses at once and irrigate immediately for at least15 min, occasionally lifting upper and lower lids. Seek medical attention immediately. If this chemical contacts theskin, remove contaminated clothing and wash immediatelywith soap and water. Seek medical attention immediately. Ifthis chemical has been inhaled, remove from exposure,begin rescue breathing (using universal precautions, including resuscitation mask) if breathing has stopped and CPR ifheart action has stopped. Transfer promptly to a medicalfacility. When this chemical has been swallowed, get medical attention. Give large quantities of water and inducevomiting. Do not make an unconscious person vomit.Medical observation is recommended for 24-48 h afterbreathing overexposure, as pulmonary edema may bedelayed. As first aid for pulmonary edema, a doctor orauthorized paramedic may consider administering a corticosteroid spray.
Carcinogenicity
No evidence of mutagenicity was seen
in Ames bacterial assays.8 Diethylamine has
an ammonia-like odor that is detectable at
0.13ppm.
The 2003 ACGIH threshold limit valuetime-
weighted average (TLV-TWA) for
diethylamine is 5ppm (15mg/m3) with
a short-term excursion limit of 15ppm
(45mg/m3) and an A4-not classifiable as a
human carcinogen designation; there is a notation
for skin absorption.
Environmental Fate
Photolytic. Low et al. (1991) reported that the photooxidation of aqueous secondary amine
solutions by UV light in the presence of titanium dioxide resulted in the formation of ammonium
and nitrate ions.
Chemical/Physical. Diethylamine reacted with NOx in the dark forming diethylnitrosamine. In
an outdoor chamber, photooxidation by natural sunlight yielded the following products:
diethylnitramine, diethylformamide, diethylacetamide, ethylacetamide, ozone, acetaldehyde, and
peroxyacetyl nitrate (Pitts et al., 1978).
Reacts with mineral acids forming water-soluble salts (Morrison and Boyd, 1971).
Metabolism
Little information is available regarding the metabolism of diethylamine. The
amine can be readily absorbed from the respiratory and gastrointestinal tract. It has
been reported that following oral administration of diethylamine hydrochloride to
humans, much of the amine was recovered in the urine (Beard and Noe 1978). This
suggests that it is not readily metabolized and, therefore, may not be a substrate for
monoamine oxidase. When administered intraperitoneally to rats, it was moderately
inhibitory with respect to liver monoamine oxidase (Valiev 1974). Diethylamine
may serve as a precursor for the formation of the reportedly carcinogenic
N-nitrosoamines and, indeed, when a diethylamine containing liquid was examined
for nitrosation reactions under simulated conditions of the human stomach,
N-nitrosodiethylamine was formed (Ziebarth 1985).
Shipping
This compound requires a shipping label of“FLAMMABLE LIQUID.” It falls in Hazard Class 3 andPacking Group II.
Purification Methods
Dry diethylamine with LiAlH4 or KOH pellets. Reflux with, and distil it from, BaO or KOH. Convert it to the p-toluenesulfonamide and crystallise to constant melting point from dry pet ether (b 90-120o), then hydrolyse with HCl, excess NaOH is added, and the amine is passed through a column of activated alumina. Redistil the amine and dry it with activated alumina before use [Swift J Am Chem Soc 64 115 1942]. [Beilstein 4 III 313.] § A polystyrene diethylaminomethyl supported version is commercially available.
Incompatibilities
Forms explosive mixture with air. Mayaccumulate static electrical charges, and may cause ignitionof its vapors. Violent reaction with strong oxidizers, strongacids, cellulose nitrate. Incompatible with organic anhydrides, isocyanates, vinyl acetate, acrylates, substitutedallyls, alkylene oxides, epichlorohydrin, ketones, aldehydes,alcohols, glycols, mercury, phenols, cresols, caprolactumsolution. Attacks aluminum, copper, lead, tin, zinc, andalloys.
