Mallinckrodt Baker -- UREA 57-13-6
Fisher - Urea, Pearls 57-13-6
Fisher - Urea 57-13-6
Fisher - Urea, Reagent ACS 57-13-6
Fisher - Urea, p.a. 57-13-6
UREA
CAS Nr 57-13-6
The following information was generated from the
Hazardous Substances Databank (HSDB),
a database of the National Library of Medicine's TOXNET system
(http://toxnet.nlm.nih.gov) on September 7, 2002.
Query: Records containing the word nr
Singular and plural forms were searched.
Information added from ChemIDplus:
Chemid Name: urea [57-13-6]
( carbamide, varioform ii, urevert, ureophil, ureaphil, pseudourea,
mocovina,
isourea, carbonyldiamine, carbonyl diamide, carbamimidic acid )
urea ( carbamide, varioform ii, urevert, ureophil, pseudourea, mocovina, isourea,
carbonyldiamine, carbonyl diamide, carbamimidic acid )
cas Chemid Name: [41427-34-3]
Registry Numbers:
57-13-6 57-13-6 41427-34-3
1
NAME: UREA
RN: 57-13-6
HUMAN HEALTH EFFECTS:
HUMAN TOXICITY EXCERPTS:
ADVERSE REACTIONS INCLUDE HEADACHE, NAUSEA,
VOMITING, SYNCOPE,
DISORIENTATION, TRANSIENT CONFUSION, &
ELECTROLYTE DEPLETION
(HYPONATREMIA & HYPOKALEMIA). [GENNARO.
REMINGTON'S PHARM SCI 17TH ED
1985 p 935]**PEER REVIEWED**
BECAUSE THE EYE IS PERMEABLE TO UREA, REBOUND
ELEVATION IN INTRAOCULAR
PRESSURE & VITREOUS VOL MAY OCCUR AFTER
OCULAR HYPOTENSIVE EFFECT HAS
TERMINATED (ABOUT 8 TO 12 HR AFTER ADMIN).
[American Medical Association,
AMA Department of Drugs, AMA Drug Evaluations.
3rd ed. Littleton,
Massachusetts: PSG Publishing Co., Inc., 1977.
936]**PEER REVIEWED**
THE SYSTEMIC TOXICITY OF UREA IS SIMILAR TO THAT
OF MANNITOL. UREA IS
IRRITATING TO TISSUES; IT CAUSES PAIN AT SITE OF
INFUSION & NECROSIS
MAY RESULT IF EXTRAVASATION OCCURS. SUPERFICIAL
& DEEP THROMBOSIS MAY
RESULT IF UREA IS INFUSED IN VEINS OF LOWER
EXTREMITIES. [American Medical
Association, AMA Department of Drugs, AMA Drug
Evaluations. 3rd ed.
Littleton, Massachusetts: PSG Publishing Co.,
Inc., 1977. 936]**PEER
REVIEWED**
HUMAN TOXICITY VALUES:
Human, skin 22 mg/3 days intermittent, toxic
effects: mild irritation
[NIOSH; Current Awareness Listing (1985)]**PEER
REVIEWED**
SKIN, EYE AND RESPIRATORY IRRITATIONS:
Urea causes redness and irritation of skin and
eyes. [Environment Canada;
Tech Info for Problem Spills: Urea p.2
(1985)]**PEER REVIEWED**
DRUG WARNINGS:
UREA SHOULD NOT BE USED IN PATIENTS WITH SEVERELY
IMPAIRED RENAL FUNCTION.
[American Medical Association, AMA Department of
Drugs, AMA Drug
Evaluations. 3rd ed. Littleton, Massachusetts:
PSG Publishing Co., Inc.,
1977. 936]**PEER REVIEWED**
UREA IS OFTEN RECONSTITUTED WITH INVERT SUGAR
SOLN. INVERT SUGAR CONTAINS
FRUCTOSE, WHICH CAN CAUSE SEVERE REACTION
(HYPOGLYCEMIA, NAUSEA, VOMITING,
TREMORS, COMA, & CONVULSIONS) IN PATIENTS
WITH HEREDITARY FRUCTOSE
INTOLERANCE (ALDOLASE DEFICIENCY). [American
Medical Association, AMA
Department of Drugs, AMA Drug Evaluations. 3rd
ed. Littleton,
Massachusetts: PSG Publishing Co., Inc., 1977.
936]**PEER REVIEWED**
PROBABLE ROUTES OF HUMAN EXPOSURE:
Occupational exposure to urea occurs through
dermal contact and inhalation
of dust, especially to workers applying urea
fertilizers(1). [(1)
Parmeggiani L; Encyl Occup Health &
Safety 3rd ed. Geneva,
Switzerland: International Labour Office p. 846-8
(1983)]**PEER REVIEWED**
The National Occupational Hazard Survey conducted
by NIOSH estimated that
855,894 workers may be exposed to urea; 7% from
actual observed use, 31%
from observed use of a tradename product known to
contain this chemical,
and 62% from observed use of a product in some
type of general use which
leads NIOSH to suspect that this chemical may be
contained in the product.
[NIOSH National Hazard Exposure Survey
(1972-1974)]**PEER REVIEWED**
NIOSH (NOES Survey 1981-1983) has statistically
estimated that 661,00
workers are potentially exposed to urea in the
USA(1). NIOSH (NOHS Survey
1972-1974) has statistically estimated that
855,894 workers are
potentially exposed to urea in the USA(2). [(1)
NIOSH; National
Occupational Exposure Survey (NOES) (1983) (2)
NIOSH; National
Occupational Hazard Survey (NOHS) (1974)]**PEER
REVIEWED**
MINIMUM FATAL DOSE LEVEL:
In ruminants unaccustomed to urea, ingestion of
0.3-0.5 g urea/kg may be
toxic ... The toxic dose of urea in (presumably
unaccustomed) cattle is
0.45 g/kg (50 g total dose) but that animals can
ingest more urea than
this if the dose is increased gradually. [Booth,
N.H., L.E. McDonald
(eds.). Veterinary Pharmacology and Therapeutics.
5th ed. Ames, Iowa: Iowa
State University Press, 1982. 1029]**PEER
REVIEWED**
EMERGENCY MEDICAL TREATMENT:
EMERGENCY MEDICAL TREATMENT:
EMT COPYRIGHT DISCLAIMER:
Portions of the POISINDEX(R) database are provided here for general
reference.
THE COMPLETE POISINDEX(R) DATABASE, AVAILABLE FROM MICROMEDEX, SHOULD
BE
CONSULTED FOR ASSISTANCE IN THE DIAGNOSIS OR TREATMENT OF SPECIFIC
CASES.
Copyright 1974-1998 Micromedex, Inc. Denver, Colorado. All Rights
Reserved.
Any duplication, replication or redistribution of all or part of
the
POISINDEX(R) database is a violation of Micromedex' copyrights and is
strictly
prohibited.<p>The following Overview, *** UREA ***, is
relevant for this HSDB
record chemical.
LIFE SUPPORT:
o This overview assumes that basic life support measures
have been
instituted.
CLINICAL EFFECTS:
SUMMARY OF EXPOSURE
0.2.1.1 ACUTE EXPOSURE
o WITH POISONING/EXPOSURE
1. Urea is considered a mild to moderate
intoxicant and a
mild irritant.
Exposure causes erythema of eyes and
skin. Urea's
systemic toxicity is similar to that of
mannitol.
o WITH THERAPEUTIC USE
1. Adverse effects include nausea,
vomiting, dizziness,
disorientation,
drowsiness, diuresis, hyponatremia,
hypokalemia, and
confusion. Urea's systemic toxicity
is similar to that of
mannitol.
o ANIMAL STUDIES - In sheep and cattle,
clinical effects
included pronounced muscle
fasciculations, trembling,
grinding teeth, dysrhythmias,
ataxia, lateral
recumbency, anuria, dry mouth,
frothy salivation,
dyspnea, bloating, abdominal
pain, regurgitation,
hyperesthesia, mydriasis and
convulsions. The primary
cause of death was
respiratory arrest. Laboratory
examination showed increased
glucose, ammonia and urea
levels.
HEENT
0.2.4.1 ACUTE EXPOSURE
o WITH POISONING/EXPOSURE
1. Eye damage is expected only when
concentrations are
high or duration of
exposure is extended . Rebound
increases in intraocular
pressure have been seen.
CARDIOVASCULAR
0.2.5.1 ACUTE EXPOSURE
o WITH THERAPEUTIC USE
1. Therapeutic administration of
intravenous solutions
may cause a fall in blood
pressure.
RESPIRATORY
0.2.6.1 ACUTE EXPOSURE
o WITH POISONING/EXPOSURE
1. Human data not found.
o ANIMAL STUDIES have shown dyspnea and
respiratory
arrest.
NEUROLOGIC
0.2.7.1 ACUTE EXPOSURE
o WITH THERAPEUTIC USE
1. Therapeutic administration of
intravenous solution has
caused intracranial
hemorrhage, headache and
confusion.
o ANIMAL STUDIES - Animals have developed
trembling,
fasciculations, hyperreflexia,
convulsions, ataxia, and
lethargy.
GASTROINTESTINAL
0.2.8.1 ACUTE EXPOSURE
o WITH THERAPEUTIC USE
1. Nausea and vomiting have been seen with
both oral and
intravenous
administration.
o ANIMAL STUDIES - Grinding teeth, dry
mouth, bloating,
and regurgitation were observed
in animals.
GENITOURINARY
0.2.10.1 ACUTE EXPOSURE
o WITH THERAPEUTIC USE
1. High urea levels will produce diuresis
and should not
be used in patients with
severely impaired renal
function.
HEMATOLOGIC
0.2.13.1 ACUTE EXPOSURE
o WITH THERAPEUTIC USE
1. Thrombosis and leukocytosis are
possible. Rapid
intravenous
administration may cause hemolysis.
DERMATOLOGIC
0.2.14.1 ACUTE EXPOSURE
o WITH POISONING/EXPOSURE
1. Is a mild skin irritant.
MUSCULOSKELETAL
0.2.15.1 ACUTE EXPOSURE
o WITH THERAPEUTIC USE
1. Urea is irritating to tissues.
Extravasation may lead
to pain and necrosis.
METABOLISM
0.2.17.1 ACUTE EXPOSURE
o WITH THERAPEUTIC USE
1. An intolerance to carbohydrates may
develop with high
urea levels.
REPRODUCTIVE HAZARDS
o Intraplacental and intrauterine administration
of urea
to humans has produced abortions.
CARCINOGENICITY
0.2.21.2 HUMAN OVERVIEW
o Carcinogenicity data are
questionable. Both negative
and positive studies have been
reported.
GENOTOXICITY
o Human mutation data have been reported.
LABORATORY:
o Follow blood urea nitrogen (BUN) to detect urea increases.
o When diuresis is extensive, follow fluids and
electrolytes.
TREATMENT OVERVIEW:
ORAL EXPOSURE
o Urea is not highly toxic, and extensive
decontamination
and treatment is seldom
necessary. Gastric
decontamination is not indicated in
high concentrations
due to possible strong irritant
effects. Gastric
decontamination may be of value with
high volumes of
lower concentrations. Activated
charcoal has not been
tested.
o Urea is effectively eliminated by the
kidney. If normal
renal function exists, diuresis will
ensue. Patients
should have adequate hydration.
If diuresis is
extensive, monitor electrolytes.
INHALATION EXPOSURE
o INHALATION: Move patient to fresh
air. Monitor for
respiratory distress. If cough
or difficulty breathing
develops, evaluate for respiratory
tract irritation,
bronchitis, or pneumonitis.
Administer oxygen and
assist ventilation as required.
Treat bronchospasm with
beta2 agonist and
corticosteroid aerosols.
o Urea would be a mild to moderate irritant if
inhaled in
an aerosol. After the exposure
has been terminated,
patients should be evaluated for
respiratory distress.
Dyspnea and respiratory failure has
been seen in
poisoned animals, respiratory support
should be
available in severe cases.
EYE EXPOSURE
o DECONTAMINATION: Irrigate exposed eyes
with copious
amounts of tepid water for at least
15 minutes. If
irritation, pain, swelling,
lacrimation, or photophobia
persist, the patient should be seen
in a health care
facility.
o Urea may be mild to moderately irritating to
the eye.
Most exposures may be handled by
irrigation and
observation for prolonged pain or
erythema (not
expected).
1. HIGH CONCENTRATIONS - or prolonged exposures
may
produce more significant
irritation and should be seen
by an ophthalmologist for
evaluation.
DERMAL EXPOSURE
o DECONTAMINATION: Remove contaminated
clothing and wash
exposed area thoroughly with
soap and water. A
physician may need to examine
the area if irritation or
pain
persists.
RANGE OF TOXICITY:
o IRRITATION -
1. SUMMARY - As with all irritants, concentration is not the
only factor which affects the extent of
tissue damage.
The concentrations below should only be
used as a rough
guide, and each patient examined
individually.
2. INHALATION - Concentrations under 50% are not likely to
cause tissue damage.
3. SKIN/MUCOUS MEMBRANES - 25% to 50% concentrations did not
produce toxicity in the ear.
4. INJECTION - SQ injection of a 6% to 30% solution did not
produce toxicity. Injection of a 58%
solution in the
uterus produced necrosis, 10% injected in
the cervix did
not.
ANTIDOTE AND EMERGENCY TREATMENT:
This should involve the use of weak acid as a
chemical antidote,
demulcents and stimulants. ... Recommended 2.5-5
l of 5% acetic acid as an
effective antidote to urea poisoning in cattle.
... /It was/ also shown
that weak acids such as acetic and propionic acid
offer some protection
against the harmful effects of urea. Drenching
with acetic acid those
animals showing signs of intoxication does not
lower their blood ammonia
concentration within 120 minutes ... . However,
administration of 2 mol of
acetic acid per mol of urea at 15 minutes, and 1
mol per mol 180 minutes
after giving 0.44 g/kg body weight of urea ...
resulted in the survival of
28 of 29 pregnant cows ... . Emptying the rumen
of fistulated cattle
showing clinical signs of poisoning results in a
rapid fall in their blood
ammonia concentration and recovery within one to
two hours ... .
[Humphreys, D.J. Veterinary Toxicology. 3rd ed.
London, England: Bailliere
Tindell, 1988. 18]**PEER REVIEWED**
In animals that are not too ill, the cold water
acetic acid treatment may
work. the adult cow is given 19-38 liters cold
water and 3.8 liters 5%
acetic acid (or vinegar) orally. This treatment
limits absorption of
ammonia from the rumen by diluting the rumen
contents and slowing the rate
of hydrolysis of urea by decreasing rumen pH and
temperature. The
treatment also promotes urine flow that, if
maintained by fluid therapy,
may assure recovery from urea toxicosis. Gaseous
or fluid bloat should be
relieved before pumping water into the rumen.
[Booth, N.H., L.E. McDonald
(eds.). Veterinary Pharmacology and Therapeutics.
5th ed. Ames, Iowa: Iowa
State University Press, 1982. 1033]**PEER
REVIEWED**
This involves chemical examination of the suspect
fertilizer, feed or
rumen contents. In most cases of urea poisoning
the ammonial level in the
rumen contents will be greater than 80 mg/100 ml
(47 mmol/l) and may be as
high as 200 mg/100 ml (117 mmol/l). It should be
remembered that rumen
contents should be examined quickly after death
or kept frozen until they
can be analysed. The reason for this is that
microbial decomposition can
produce ammonia and thus lead to misleading
results. The possible uneven
distribution of the causal agent in feed and
rumen contents must be borne
in mind when collecting samples for chemical
examination. Blood and serum
ammonia nitrogen concentrations between 2 and 4
mg/100 ml (1.17 and 2.35
mmol/l) or greater which are associated with urea
poisoning may also have
diagnostic applications. [Humphreys, D.J.
Veterinary Toxicology. 3rd ed.
London, England: Bailliere Tindell, 1988.
18]**PEER REVIEWED**
ANIMAL TOXICITY STUDIES:
NON-HUMAN TOXICITY EXCERPTS:
INTRAVITREAL INJECTION OF 0.2 ML OF 10 MOLAR /SOLN
INTO VITREOUS HUMOR OF/
RABBITS HAS CAUSED INFLAMMATION, CHORIORETINITIS,
& DEGENERATION OF
RETINA. [Grant, W.M. Toxicology of the Eye. 3rd
ed. Springfield, IL:
Charles C. Thomas Publisher, 1986. 965]**PEER
REVIEWED**
UREA MIXED WITH SOYA MEAL IS PARTICULARLY
DANGEROUS, AS UREASE IN LATTER
LEADS TO FORMATION OF AMMONIA ... POISONING OF
CATTLE MAY ALSO BE CAUSED
BY UREA AS FERTILIZER & SPREAD UNEVENLY
ON PASTURE [Clarke, E.G., and
M. L. Clarke. Veterinary Toxicology. Baltimore,
Maryland: The Williams and
Wilkins Company, 1975. 30]**PEER REVIEWED**
LAMBS GIVEN 2 G/KG OF UREA DIED IN 90-200 MIN.
ADULT SHEEP GIVEN SAME DOSE
EXHIBITED ALMOST CONTINUOUS CONVULSIONS AFTER 165
MIN ... SHEEP CAN
CONSUME UP TO 100 G OF UREA A DAY PROVIDED THAT
CONCN OF UREA IN RATION
DOES NOT EXCEED 6% ... LIVER DYSFUNCTION INCR
SUSCEPTIBILITY TO POISONING.
[Clarke, E.G., and M. L. Clarke. Veterinary
Toxicology. Baltimore,
Maryland: The Williams and Wilkins Company, 1975.
30]**PEER REVIEWED**
... ORAL ADMIN OF 50 G OF UREA KILLED 4 OUT OF 5
GOATS WITHIN 30 MIN, 450
G GIVEN BY MOUTH KILLED 7 PONIES OUT OF 8 ...
[Clarke, E.G., and M. L.
Clarke. Veterinary Toxicology. Baltimore,
Maryland: The Williams and
Wilkins Company, 1975. 30]**PEER REVIEWED**
TOXIC DOSE IN CATTLE GIVEN UREA FOR FIRST TIME IS
VARIOUSLY CONSIDERED TO
BE 0.45 G/KG ... OR TOTAL OF 100-200 G ... SLOWLY
INCR UREA CONTENT OF
FEED, MATURE BULLOCKS CAN DIGEST AS MUCH AS 400 G
A DAY WITHOUT ILL
EFFECT. AS LITTLE AS 50 G MAY CAUSE POISONING IN
CATTLE NOT ACCUSTOMED TO
IT ... . [Clarke, E.G., and M. L. Clarke.
Veterinary Toxicology.
Baltimore, Maryland: The Williams and Wilkins
Company, 1975. 30]**PEER
REVIEWED**
Urea was tested for mutagenicity in the
Salmonella/microsome preincubation
assay using the standard protocol approved by the
National Toxicology
Program. Urea was tested at doses of 0.10, 0.33,
1.0, 3.3, and 10 mg/plate
in as many as 5 Salmonella typhimurium strains
(TA1535, TA1537, TA97,
TA98, and TA100) in the presence and absence of
rat or hamster liver S-9.
Urea was negative in these tests and the highest
ineffective dose tested
in any Salmonella typhimurium strain was 10
mg/plate. [Mortelmans K et al;
Environ Mutagen 8:1-119 (1986)]**PEER REVIEWED**
Single doses of 16 g/kg body weight and 10% of
urea in the feed has been
reported to have no apparent effect on ten week
old piglets ... . Although
the highest level made the feed unpalatable,
incorporation of 0.4, 0.6 or
1.0 g of urea per kg body weight into the ration
of 18 month old pigs
weighing 120-140 kg also failed to produce
intoxication ... . [Humphreys,
D.J. Veterinary Toxicology. 3rd ed. London,
England: Bailliere Tindell,
1988. 17]**PEER REVIEWED**
Administration of 450 g of urea, which caused the
death of seven of eight
ponies, resulted in an increase in blood urea,
ammonia,
alphaketoglutarate, glucose and pyruvate
concentrations. The sequence and
nature of the changes produced suggested that
inhibition of
alphaketoglutarate decarboxylation may be the
primary site of ammonia
intoxication. [Humphreys, D.J. Veterinary
Toxicology. 3rd ed. London,
England: Bailliere Tindell, 1988. 17]**PEER
REVIEWED**
Urea poisoning has been reported in sheep which
drank a 21% solution used
as a fertilizer for cotton ... and in those
consuming treated rations ...
. Sheep grazing pastures low in protein are
particularly susceptible to
urea poisoning ... . The short term feeding of
protein concentrates before
giving urea supplements can increase sheep's
tolerance to urea ... .
Experimental administration of 0.5 g/kg of urea
has been shown to cause
intoxication in the heaviest, while 0.8 g/kg
resulted in poisoning in all
the treated sheep ... . Urea poisoning in sheep
is associated with an
elevated blood ammonia concentration, increased
erythrocyte counts and
packed cell volume values, and decreased
leucocyte counts ... . Detailed
clinical biochemical studies on experimental urea
poisoned sheep have been
reported ... . The blood ammonia concentration of
the fetus in fatally
poisoned sheep is lower than that of the dam at
death, and the ammonia
concentrations in their livers, kidneys, spleen
and muscles are similarly
different. [Humphreys, D.J. Veterinary
Toxicology. 3rd ed. London,
England: Bailliere Tindell, 1988. 17]**PEER
REVIEWED**
On rabbit eyes saturated urea solution causes
loss of epithelium from the
cornea after five minutes contact, and produces
moderate grayness of the
stroma, with subsequent slow regeneration of the
epithelium. A rabbit's
cornea can return to normal in several weeks
after exposure for an hour to
40% urea solution. [Grant, W.M. Toxicology of the
Eye. 3rd ed.
Springfield, IL: Charles C. Thomas Publisher,
1986. 965]**PEER REVIEWED**
Intravenous urea in monkeys has not damaged the
ciliary epithelium,
supporting a belief that reduction of intraocular
pressure in glaucomatous
patients is accomplished by an osmotic, rather
than a toxic mechanism.
However, intracarotid injection of concentrated
urea in monkeys has done
dramatic damage to the retina and the ciliary
body. Retinal pigment
epithelial cells are affected and blood-retina
barrier broken down. The
blood-aqueous barrier is broken down secondary to
changes in the
capillaries and selective damage to the ciliary
body epithelium.
Intraocular pressure is strikingly reduced and
the aqueous outflow system
rapidly shows swelling of the connective tissue
of the inner wall of
Schlemm's canal, and then edema of the trabecular
meshwork. However, in
several weeks there is general return to normal,
except for failure of
pigmented ciliary epithelium to regenerate.
[Grant, W.M. Toxicology of the
Eye. 3rd ed. Springfield, IL: Charles C. Thomas
Publisher, 1986.
965]**PEER REVIEWED**
Serine-specific reagents, anticholinesterase
organophosphorus compounds
like VX provoke, in the micromolar range,
digitalis-like ventricular
arrhythmias of non-cholinergic origin in rodent
hearts. The sensitivities
of the two rat cardiac sodium + or - potassium
ATPase isoforms (alpha 1
and alpha 2) to VX (0.1-100 uM) were measured in
sarcolemma vesicles. At 1
microM VX, the inhibition of the total activity
averaged 18% but never
exceeded 75% with 100 uM. When the alpha 2
isoform activity was inhibited
by 0.1 uM ouabain, alpha 1 was 35% inhibited by 1
uM VX, i.e. a 16 + or -
4% inhibition of the total activity. The cardiac
alpha 1 being related to
the digitalis-induced toxicity, its selective
inhibition by a micromolar
dose of VX fully accounts for the cardiotoxicity
of VX. Inasmuch as VX had
no effect on the rat kidney alpha 1,
differentially inactivated the
cardiac isozymes and specifically reacted with
serine residues, the
putative binding-site(s) of the organophosphorus
compound on the sodium +
or - potassium ATPase molecules has been
indicated. [Robineau P et al;
FEBS Lett 281 (1-2): 145-8 (1991)]**PEER
REVIEWED**
Accidental urea intoxication resulted in the
death of 17 of 29 suckler
cows within six hours after the contamination of
their drinking water with
urea fertiliser. The other cows showed no lasting
ill effects and neither
their three-month-old calves nor the stock bull
were affected. The urea
concentration in the water was 86 mmol/litre, and
the concentrations of
ammonia nitrogen in the rumen fluid of two of the
cows which were examined
after death were 1825 and 957 mg/litre. [Caldow
GL, Wain EB; Vet Rec 128
(21): 489-91 (1991)]**PEER REVIEWED**
NON-HUMAN TOXICITY VALUES:
LD100 Sheep 500 mg/l; mean survival time: 165
minutes [Edjtehad; M et al;
Canadian J Comp Med 64 (1): 63-68 (1978) as cited
in Environment Canada;
Tech Info for Problem Spills: Urea p.46
(1985)]**PEER REVIEWED**
LD50 Sheep acute oral 28.5 g/100 kg [Booth, N.H.,
L.E. McDonald (eds.).
Veterinary Pharmacology and Therapeutics. 5th ed.
Ames, Iowa: Iowa State
University Press, 1982. 1029]**PEER REVIEWED**
METABOLISM/PHARMACOKINETICS:
ABSORPTION, DISTRIBUTION & EXCRETION:
SOME SMALL, WATER SOL, BUT NONIONIZABLE COMPD
SUCH AS UREA READILY
TRAVERSE MAMMALIAN MEMBRANES, PROBABLY ALONG WITH
WATER, BY WAY OF THE
PORES. THIS FILTRATION PROCESS IS PARTICULARLY
RAPID BETWEEN CAPILLARIES
& EXTRACELLULAR FLUID. [Hayes, W. J., Jr.
Toxicology of Pesticides
Baltimore: Williams & Wilkins, 1975.
130]**PEER REVIEWED**
... UREA ... PENETRATES OTHER CELLS RAPIDLY,
ENTERS THE BRAIN ONLY VERY
SLOWLY ... [LaDu, B.N., H.G. Mandel, and E.L.
Way. Fundamentals of Drug
Metabolism and Disposition. Baltimore: Williams
and Wilkins, 1971.
51]**PEER REVIEWED**
... DISTRIBUTED APPROX IN TOTAL BODY WATER ...
HAVE BEEN USED FOR
MEASUREMENT OF TOTAL BODY WATER. [LaDu, B.N., H.G.
Mandel, and E.L. Way.
Fundamentals of Drug Metabolism and Disposition.
Baltimore: Williams and
Wilkins, 1971. 53]**PEER REVIEWED**
EXCRETION OF UREA DURING SWEATING IN MAN: 1.84
SWEAT/PLASMA RATIO WITH PKA
@ 13.8. /FROM TABLE/ [LaDu, B.N., H.G. Mandel,
and E.L. Way. Fundamentals
of Drug Metabolism and Disposition. Baltimore:
Williams and Wilkins, 1971.
143]**PEER REVIEWED**
Regional variations in the absorption of benzoic
acid, cortisone, urea,
and water in sections obtained from the back and
abdominal skin of male
and female Osborne-Mendel rats were determined
using in vitro diffusion
cell techniques. Skin permeability constants and
lag times were determined
for the substances. Benzoic acid was absorbed
from a petrolatum vehicle,
and the other compounds were applied to the skin
samples in an aqueous
solution. Differences in absorption were compared
with skin thickness
measurements. The mechanism of sex related
permeability differences was
studied in castrated rats with subsequent
permeability and histological
examination of the skin. Results showed a sex
related difference in
variation of absorption in the back and abdominal
skin of both sexes. In
general, female back skin was approximately twice
as permeable as male
back skin. Abdominal skin, particularly in the
male rat, was more
permeable than back skin. The male rat back
stratum corneum was
approximately twice as thick as that of the
female, correlating with the
observed permeability differences. Similar
stratum corneum thicknesses
were observed in the abdominal skin from both
sexes. The back skin of
castrated males was similar in permeability and
thickness to that of the
females. [Bronaugh RL et al; J Soc Cosmet Chem
34: 127-35 (1983)]**PEER
REVIEWED**
The maternal and newborn renal function in 84
normal pregnant women
delivering at term was investigated. There was no
difference between
maternal and newborn plasma concentrations of
urea (3.9 + or - 1.0 vs. 3.9
+ or - 1.2 mmol/l) and creatinine (65.8 + or -
13.3 vs. 65.3 + or - 11.6
mumols/l). Newborn urea with maternal urea
concentrations (p = 0.0001),
and newborn creatinine with maternal creatinine
concentrations (p =
0.0001). [Lao TT et al; Gynecol Obstet Invest 28
(2): 70-2 (1989)]**PEER
REVIEWED**
MECHANISM OF ACTION:
... The primary mechanism of ammonia toxicosis
appears to be inhibition of
the citric acid cycle. There is an increase in
anaerobic glycolysis, blood
glucose, and blood lactate ... . Acidosis is
manifested. The exact means
by which ammonia blocks the citric acid cycle is
not known. It is
postulated that ammonia saturation of the
glutamine-synthesizing system
causes a backing-up in the citrate cycle, a
decrease in its intermediates,
and a decrease in energy production and cellular
respiration, which leads
to convulsions ... . The decrease of citrate
cycle intermediates is
postulated to result from reamination of pyruvic,
ketoglutaric, and
oxaloacetic acids. [Booth, N.H., L.E. McDonald
(eds.). Veterinary
Pharmacology and Therapeutics. 5th ed. Ames,
Iowa: Iowa State University
Press, 1982. 1031]**PEER REVIEWED**
INTERACTIONS:
A case of sudden collapse after the
intra-amniotic injection of 5 mg
dinoprostone (Prostaglandin E2) and 40 g urea for
pregnancy termination in
a 36 yr old woman after the diagnosis of fetal
Down's syndrome is
reported. Within one minute of injection of a
test dose of one mg of
dinoprostone, the patient collapsed. Intravenous
injections of 100 mg
hydrocortisone and 10 mg chlorpheniramine maleate
were administered and
the patient was given oxygen by a face mask.
Within 10 minutes blood
pressure had returned to 110/68 mm Hg, and after
a further 15 minutes
pulse rate was normal. [Cameron IT, Baird DT;
Lancet 2: 1046-7
(1984)]**PEER REVIEWED**
TREATMENT OF GUINEA PIGS WITH UREA INCR THE
EFFECT OF THEIR SUBSEQUENT
SENSITIZATION WITH EPOXY RESIN (EGK-19) OR
K2CR207. UREA TREATMENT INCR
PERCENTAGE OF ANIMALS SENSITIZED BY EPOXY RESINS
FROM 50-87%. UREA ALONE
DID NOT SENSITIZE SKIN. [ZIGLER F, ROETER A;
DERMATOL VENEROL (SOFIA) 18
(1): 25-28 (1979)]**PEER REVIEWED**
The hemolytic action on human red blood cells (RBC)
and the aggregations
of human and rat red blood cells in the presence
of sodium alginate were
studied. Sodium alginate had no hemolytic action
on human red blood cells.
Human and rat red blood cells showed a marked
aggregation by sodium
alginate in a neutral medium. Sodium alginates
having larger molecular
weights showed more pronounced activities for
aggregation of red blood
cells as compared with those having smaller
molecular weights, and the
aggregation of red blood cells increased with an
increase in the
concentration of sodium alginate. The aggregation
was inhibited by urea,
suggesting the aggregation of red blood cells is
caused by hydrogen
bonding. When sodium alginate was added to human
or rat blood rouleaux
formation of red blood cells covered with fibrin
net was observed in the
coagulation cruor (blood clot). [Daigo K et al;
Yakugaku Zasshi 102 (6):
573-578 (1982)]**PEER REVIEWED**
Osmotic diuretics (mannitol, urea) decrease the
effect on serum lithium
level; significant increase in lithium excretion.
/Lithium-drug
interactions; from table/ [Ellenhorn, M.J. and
D.G. Barceloux. Medical
Toxicology - Diagnosis and Treatment of Human
Poisoning. New York, NY:
Elsevier Science Publishing Co., Inc. 1988.
1043]**PEER REVIEWED**
PHARMACOLOGY:
THERAPEUTIC USES:
Dermatologic Agents; Diuretics, Osmotic [National
Library of Medicine's
Medical Subject Headings online file (MeSH,
1999)]**QC REVIEWED**
UREA IS /USED LESS COMMONLY THAN OTHER OSMOTIC
AGENTS/ FOR THE SHORT-TERM
REDUCTION OF INTRAOCULAR PRESSURE &
VITREOUS VOL ... IN ANGLE-CLOSURE
GLAUCOMA .. PRIOR TO SURGERY ... IN CHRONIC
GLAUCOMA ... PRE- AND
POSTOPERATIVE TREATMENT. [American Medical
Association. AMA Drug
Evaluations Annual 1991. Chicago, IL: American
Medical Association, 1991.
1825]**PEER REVIEWED**
DOSE--USUAL, IV INFUSION, 100 MG TO 1 G/KG DAILY,
AS 30% SOLN IN DEXTROSE
INJECTION @ RATE NOT EXCEEDING 4 ML/MIN. [GENNARO.
REMINGTON'S PHARM SCI
17TH ED 1985 p 935]**PEER REVIEWED**
USED TOPICALLY IN THE TREATMENT OF PSORIASIS,
ICHTHYOSIS, ATOPIC
DERMATITIS, AND OTHER DRY, SCALY CONDITIONS. [GENNARO.
REMINGTON'S PHARM
SCI 17TH ED 1985 p 785]**PEER REVIEWED**
Experimental: A study was made in which 57
symmetrically affected
psoriatic patients applied to their lesions on
opposite sides either 0.1%
dithranol (anthralin) /urea cream (Psordrate
0.1%) or 0.1% beta-methasone
valerate (Betnovate). After six weeks the
dithranol/ urea cream proved to
be more effective. [Ferguson A, Maden CJ; Br J
Clin Prac 36: 60-67
(1982)]**PEER REVIEWED**
The efficacy of oral urea in producing a
sufficiently high osmotic
diuresis was studied in 7 patients with the
syndrome of inappropriate
secretion of antidiuretic hormone. In all
patients, urea corrected the
hyponatremia despite a normal fluid intake. Five
patients were controlled
with a dose of 30 g daily. The patients who
needed 30 g drank up to 2
liters of fluid daily, while those who needed 60
g drank up to 3
liters/day. No major side effects were noted,
even after treatment periods
of up to 270 days. It was concluded that urea is
a safe and efficacious
treatment of the syndrome of inappropriate
secretion of antidiuretic
hormone. [Decaux G, Genette F; Br Med 283:
1081-1083 (1981)]**PEER
REVIEWED**
Experimental: Use of urea kinetics in the
estimation of protein balance of
nutritionally unstable renal failure patients,
and for optimal management
of nutrition therapy. [Bennett N; Nutr Support
Serv 4: 21-25 (1984)]**PEER
REVIEWED**
Experimental: A number of studies evaluating an
osmotic cervical dilator
consisting of polyvinyl foam saturated with
magnesium sulfate in women
undergoing mid trimester abortion with
intra-amniotic hyperosmolar urea
plus prostaglandin F2A were completed.
Comparisons with women receiving no
pre-treatment with a laminaria tent or with one
laminaria indicate that
their use appears to shorten injection-abortion
intervals, particularly in
parous women, and reduce risk of endometritis and
cervical laceration
compared to women not receiving any type of
device. The data suggests that
two osmotic dilators may be more effective than
one. Also, magnesium
toxicity does not appear to be a substantial risk
with their use. [Atienza
MF et al; Contraception 30 (3): 215-223
(1984)]**PEER REVIEWED**
EXPTL: REPORTED HELPFUL IN TREATING SICKLE-CELL
CRISIS [Hawley, G.G. The
Condensed Chemical Dictionary. 9th ed. New York:
Van Nostrand Reinhold
Co., 1977. 905]**PEER REVIEWED**
In patients with squamous cell carcinoma of
palpebral and bulbar
conjunctiva, repeated applications of urea powder
have been made to
eradicate the malignant growth. [Grant, W.M.
Toxicology of the Eye. 3rd
ed. Springfield, IL: Charles C. Thomas Publisher,
1986. 965]**PEER
REVIEWED**
A sterile preparation of urea (UREAPHIL) is
available that may be
reconstituted for intravenous use. When
administered in this manner, the
solution contains 30% urea and either 5 or 10%
dextrose or invert sugar
(equal parts of dextrose and fructose).
Intravenous doses of 1 to 1.5 g of
urea per kilogram of body weight are optimal in
preparation for
neurosurgical procedures or for reduction of
intraocular pressure. On a
molar basis urea is less effective as a diuretic
than is mannitol, since
approximately 50% of the compound is reabsorbed
from the tubular fluid.
[Gilman, A.G., T.W. Rall, A.S. Nies and P. Taylor
(eds.). Goodman and
Gilman's The Pharmacological Basis of
Therapeutics. 8th ed. New York, NY.
Pergamon Press, 1990. 715]**PEER REVIEWED**
UREA HAS BEEN USED AS AN INSECT (MOSQUITO)
REPELLENT. [HILL JA ET AL; MOSQ
NEWS 39 (2): 307-310 (1979)]**QC REVIEWED**
DRUG WARNINGS:
UREA SHOULD NOT BE USED IN PATIENTS WITH SEVERELY
IMPAIRED RENAL FUNCTION.
[American Medical Association, AMA Department of
Drugs, AMA Drug
Evaluations. 3rd ed. Littleton, Massachusetts:
PSG Publishing Co., Inc.,
1977. 936]**PEER REVIEWED**
UREA IS OFTEN RECONSTITUTED WITH INVERT SUGAR
SOLN. INVERT SUGAR CONTAINS
FRUCTOSE, WHICH CAN CAUSE SEVERE REACTION
(HYPOGLYCEMIA, NAUSEA, VOMITING,
TREMORS, COMA, & CONVULSIONS) IN PATIENTS
WITH HEREDITARY FRUCTOSE
INTOLERANCE (ALDOLASE DEFICIENCY). [American
Medical Association, AMA
Department of Drugs, AMA Drug Evaluations. 3rd
ed. Littleton,
Massachusetts: PSG Publishing Co., Inc., 1977.
936]**PEER REVIEWED**
INTERACTIONS:
A case of sudden collapse after the
intra-amniotic injection of 5 mg
dinoprostone (Prostaglandin E2) and 40 g urea for
pregnancy termination in
a 36 yr old woman after the diagnosis of fetal
Down's syndrome is
reported. Within one minute of injection of a
test dose of one mg of
dinoprostone, the patient collapsed. Intravenous
injections of 100 mg
hydrocortisone and 10 mg chlorpheniramine maleate
were administered and
the patient was given oxygen by a face mask.
Within 10 minutes blood
pressure had returned to 110/68 mm Hg, and after
a further 15 minutes
pulse rate was normal. [Cameron IT, Baird DT;
Lancet 2: 1046-7
(1984)]**PEER REVIEWED**
TREATMENT OF GUINEA PIGS WITH UREA INCR THE
EFFECT OF THEIR SUBSEQUENT
SENSITIZATION WITH EPOXY RESIN (EGK-19) OR
K2CR207. UREA TREATMENT INCR
PERCENTAGE OF ANIMALS SENSITIZED BY EPOXY RESINS
FROM 50-87%. UREA ALONE
DID NOT SENSITIZE SKIN. [ZIGLER F, ROETER A;
DERMATOL VENEROL (SOFIA) 18
(1): 25-28 (1979)]**PEER REVIEWED**
The hemolytic action on human red blood cells (RBC)
and the aggregations
of human and rat red blood cells in the presence
of sodium alginate were
studied. Sodium alginate had no hemolytic action
on human red blood cells.
Human and rat red blood cells showed a marked
aggregation by sodium
alginate in a neutral medium. Sodium alginates
having larger molecular
weights showed more pronounced activities for
aggregation of red blood
cells as compared with those having smaller
molecular weights, and the
aggregation of red blood cells increased with an
increase in the
concentration of sodium alginate. The aggregation
was inhibited by urea,
suggesting the aggregation of red blood cells is
caused by hydrogen
bonding. When sodium alginate was added to human
or rat blood rouleaux
formation of red blood cells covered with fibrin
net was observed in the
coagulation cruor (blood clot). [Daigo K et al;
Yakugaku Zasshi 102 (6):
573-578 (1982)]**PEER REVIEWED**
Osmotic diuretics (mannitol, urea) decrease the
effect on serum lithium
level; significant increase in lithium excretion.
/Lithium-drug
interactions; from table/ [Ellenhorn, M.J. and
D.G. Barceloux. Medical
Toxicology - Diagnosis and Treatment of Human
Poisoning. New York, NY:
Elsevier Science Publishing Co., Inc. 1988.
1043]**PEER REVIEWED**
MINIMUM FATAL DOSE LEVEL:
In ruminants unaccustomed to urea, ingestion of
0.3-0.5 g urea/kg may be
toxic ... The toxic dose of urea in (presumably
unaccustomed) cattle is
0.45 g/kg (50 g total dose) but that animals can
ingest more urea than
this if the dose is increased gradually. [Booth,
N.H., L.E. McDonald
(eds.). Veterinary Pharmacology and Therapeutics.
5th ed. Ames, Iowa: Iowa
State University Press, 1982. 1029]**PEER
REVIEWED**
ENVIRONMENTAL FATE & EXPOSURE:
ENVIRONMENTAL FATE/EXPOSURE SUMMARY:
Urea occurs naturally in urine and animal waste
and can be formed
naturally in the environment through protein
metabolism. It is
artificially released to the environment through
direct application to
soil as a nitrogen-release fertilizer. If
released to the atmosphere, urea
will degrade rapidly in the vapor-phase by
reaction with photochemically
produced hydroxyl radicals (half-life of 9.6 hr).
If released to soil,
urea is hydrolyzed to ammonium through soil
urease activity (the basis of
its use as a fertilizer). The rate of hydrolysis
can be fast (24 hr);
however, a number a variables (such as increasing
the pellet size of the
fertilizer) can decrease the degradation rate
from days to weeks. If
released to water, urea can degrade readily
through biotic hydrolysis as
demonstrated by various screening studies. The
presence of
naturally-occurring phytoplankton increases the
degradation rate because
phytoplankton use urea as a nitrogen source and
because urea is decomposed
by phytoplankton photosynthesis. In
phytoplankton-rich waters, degradation
occurs much faster in sunlight than in the dark.
Abiotic hydrolysis of
urea occurs very slowly in relation to biotic
hydrolysis. Occupational
exposure to urea occurs through dermal contact
and inhalation of dust,
especially to workers applying urea fertilizers.
(SRC) **PEER REVIEWED**
PROBABLE ROUTES OF HUMAN EXPOSURE:
Occupational exposure to urea occurs through
dermal contact and inhalation
of dust, especially to workers applying urea
fertilizers(1). [(1)
Parmeggiani L; Encyl Occup Health &
Safety 3rd ed. Geneva,
Switzerland: International Labour Office p. 846-8
(1983)]**PEER REVIEWED**
The National Occupational Hazard Survey conducted
by NIOSH estimated that
855,894 workers may be exposed to urea; 7% from
actual observed use, 31%
from observed use of a tradename product known to
contain this chemical,
and 62% from observed use of a product in some
type of general use which
leads NIOSH to suspect that this chemical may be
contained in the product.
[NIOSH National Hazard Exposure Survey
(1972-1974)]**PEER REVIEWED**
NIOSH (NOES Survey 1981-1983) has statistically
estimated that 661,00
workers are potentially exposed to urea in the
USA(1). NIOSH (NOHS Survey
1972-1974) has statistically estimated that
855,894 workers are
potentially exposed to urea in the USA(2). [(1)
NIOSH; National
Occupational Exposure Survey (NOES) (1983) (2)
NIOSH; National
Occupational Hazard Survey (NOHS) (1974)]**PEER
REVIEWED**
NATURAL POLLUTION SOURCES:
Urea is a natural product of nitrogen and protein
metabolism(1,3); it
occurs in urine(2) and animal waste(3). Urea can
be formed in natural
waters as a result of protein decomposition(3).
[(1) Windholz M; The Merck
Index 10th ed. Rahway, NJ: Merck & Co p.
1410 (1983) (2) Mavrovic I,
Shirley AR Jr; Kirk-Othmer Encycl Chem Technol
3rd ed, NY: John Wiley
& Sons Inc 23: 548 (1983) (3) Brockett
OD; Water Res 11: 317-21
(1977)]**PEER REVIEWED**
ARTIFICIAL POLLUTION SOURCES:
In its primary use, urea is released to the
environment through direct
application to soil as a nitrogen-release
fertilizer(1). Small amounts of
urea can be released in wastewater effluents from
manufacturing and use
sites(1). [(1) Mavrovic I, Shirley AR Jr; Kirk-Othmer
Encycl Chem Technol
3rd ed. NY: John Wiley & Sons Inc 23:
548-75 (1983)]**PEER REVIEWED**
ENVIRONMENTAL FATE:
Terrestial Fate: A forest fertilization study led
to the conclusion that
application rates less than 224 kg/ha (200 lb
N2/acre) were ineffective in
supplying nitrogen. Urea applications above this
threshold brought about
increases in soil nitrogen, pH, absorbed ammonia,
and cation exchange
capacity, the latter especially in surface and
litter material. Addition
of urea appeared to have adverse effects on the
uptake of phosphorus.
[Baker J; Some Effects of Urea Fertilization on
Soil Characteristics and
Tissue Mineral Content in Overstocked Western
Hemlock Stands. Canadian
Forestry Service Report No. BC-X-39 (1970) as
cited in Environment Canada;
Tech Info for Problem Spills: Urea p.47
(1985)]**PEER REVIEWED**
Terrestrial Fate: Urea fertilizer was applied to
a pasture and the runoffs
were measured. Maximum concn of runoff was
attained for ammonia nitrogen 3
weeks after application and for nitrate nitrogen
1 week after application.
In the runoff, ammonia-nitrogen was only 0.3% of
that applied, nitrogen
nitrate was 1.0%, and total nitrogen was 7.1% of
that applied. It was
concluded that most of the applied urea will not
run off. [Sharpley AN et
al; Water, Air and Soil Pollution 14 (3): 425-430
(1983) as cited in
Environment Canada; Tech Info for Problem Spills:
Urea p.47 (1985)]**PEER
REVIEWED**
Terrestrial and Aquatic Fate: If the soil surface
is saturated with
moisture at the time of the spill, as might be
the case after a rainfall,
the spilled /urea/ may run off into the surface
water. ... Upon reaching
the groundwater table, the contaminant will
continue to move, now in the
direction of groundwater flow. A contaminated
plume will be produced, with
diffusion and dispersion serving to reduce the
acid concn. [Environment
Canada; Tech Info for Problem Spills: Urea p.37
(1985)]**PEER REVIEWED**
Terrestrial Fate: When solid urea is spilled,
only a limited groundwater
contamination hazard exists if the soil is dry
and if no precipitation
falls prior to cleanup. ... Concentrated
solutions of /urea/ can
infiltrate the soil. Some interaction between
urea and the soil will
occur. However, much of the urea exchanged ions
will migrate downward
/SRP: as well as lateral/ through the soil.
[Environment Canada; Tech Info
for Problem Spills: Urea p.37 (1985)]**PEER
REVIEWED**
TERRESTRIAL FATE: Various field and laboratory
studies have demonstrated
that urea degrades rapidly in most soils(1-3). In
general, urea is rapidly
hydrolyzed to ammonium through soil urease
activity(1). In various soils,
the hydrolysis may near completion within 24
hrs(2); however, the rate of
hydrolysis can be much slower depending upon soil
type, moisture content,
and urea formulation(1). For example, increasing
the pellet size of urea
fertilitizers can decrease the urea decomposition
rate from days to
weeks(1). Soil adsorption studies have
demonstrated that urea adsorbs very
weakly to soil(4); therefore, leaching is
possible(SRC). Ultimate urea
degradation produces ammonia and CO2 as volatile
products(5). [(1) Malhi
SS, Nyborg M; Plant Soil 51: 177-86 (1979) (2)
Sankhayan SD, Shukla UC;
Geoderma 16: 171-8 (1976) (3) Scheunert I et al;
Chemosphere 16: 1031-41
(1987) (4) Hance RJ; Weed Res 5: 98-107 (1965)
(5) Mavrovic I, Shirley AR
Jr; Kirk-Othmer Encycl Chem Technol 3rd ed. NY:
John Wiley & Sons Inc
23: 548 (1983)]**PEER REVIEWED**
AQUATIC FATE: Biodegradation is expected to be
the major fate process in
the aquatic ecosystem. Various screening studies
have demonstrated that
urea can biodegrade readily(1-5) with the release
of CO2 and ammonia. The
rate of biodegradation generally decreases with
decreasing
temperatures(4); under cold winter-like
conditions, biodegradation may be
relatively slow (0-6% per day)(4). The presence
of naturally-occurring
phytoplankton increases the degradation rate(2,5)
because phytoplankton
use urea as a nitrogen source(2) and because urea
is decomposed by
phytoplankton photosynthesis(5); in
phytoplankton-rich waters, degradation
occurs much faster in sunlight than in the
dark(5). Abiotic hydrolysis of
urea occurs very slowly in relation to biotic
hydrolysis(6); abiotic
hydrolysis yields ammonium carbamate which
decomposes to form CO2 and
ammonia(6); the enzyme urease catalyzes urea
hydrolysis(6).
Volatilization, bioconcentration and adsorption
to sediment are not
expected to be important fate processes(SRC).
[(1) Freitag D et al;
Chemosphere 14: 1589-616 (1985) (2) Remsen CC;
Ecology 53: 921-6 (1972)
(3) Scheunert I et al; Chemosphere 16: 1031-41
(1987) (4) Evans WH et al;
Water Res 7: 975-85 (1973) (5) Mitamura O, Saijo
Y; Marine Biology 58:
147-152 (1980) (6) Stiff MJ, Gardiner DK; Water
Treat Exam 22: 259-68
(1973)]**PEER REVIEWED**
ATMOSPHERIC FATE: Based upon a vapor pressure of
1.2X10-5 mm Hg at 25 deg
C(1), urea can exist in both the vapor and
particulate-phases in the
ambient atmosphere, although the vapor-phase can
be expected to
dominate(2,SRC). It will degrade rapidly in the
vapor-phase by reaction
with photochemically produced hydroxyl radicals
with an estimated
half-life of 9.6 hr(3,SRC). Particulate-phase
urea and aerosols released
to air during spray applications of urea
fertilizers will be removed from
air physically by dry and wet deposition(SRC).
[(1) Jones AH; J Chem Eng
Data 5: 196-200 (1960) (2) Bidleman TF; Environ
Sci Technol 22: 361-7
(1988) (3) Atkinson R; Environ Toxicol Chem 7:
435-42 (1988)]**PEER
REVIEWED**
ENVIRONMENTAL BIODEGRADATION:
Waste water treatment: degradation rate by
psychrophilic bacteria: at 20
deg C: maximum: 11.6 mg/l/hr with an average of
10.9 mg/l/hr; at 2 deg C:
maximum: 4.0 mg/l/hr with an average of 3.2
mg/l/hr. [Verschueren, K.
Handbook of Environmental Data of Organic
Chemicals. 2nd ed. New York, NY:
Van Nostrand Reinhold Co., 1983. 1178]**PEER
REVIEWED**
At 100 mg/l, no inhibition of NH3 oxidation by
Nitrosomonas sp /was
observed/. [Verschueren, K. Handbook of
Environmental Data of Organic
Chemicals. 2nd ed. New York, NY: Van Nostrand
Reinhold Co., 1983.
1178]**PEER REVIEWED**
/Urea concentrations/ from 1 to 15 mg/l for up to
14 days in river water
at < 8 deg C exhibited
negligible degradation; the same concentrations
at 4 to 6 days in river water a 20 deg C
exhibited complete degradation.
/Data derived from table/ [Evans WH, Patterson S;
Water Res 7: 975-985
(1973) as cited in Environment Canada; Tech Info
for Problem Spills: Urea
p.48 (1985)]**PEER REVIEWED**
Using an activated sludge seed, a CO2 evolution
of 85.9% was measured over
a 5-day incubation period(1). At the relatively
high concns of 20-100 ppm,
5-day theoretical BODs of 0% were measured in
freshwater and synthetic
seawater to which a raw wastewater seed was
added(2). In a river die-away,
1.05-2.20% of added urea hydrolyzed after 10-days
while only 0.35%
hydrolyzed in sterile controls(3). Urea was
completely biodegraded in
aerobic biodegradation studies using activated
sludge and a 14-day
incubation period(4). In degradation studies
using estuary and coastal
waters from Georgia, avg urea degradation rates
of 6.2 to 19.6 nmoles/L-hr
were observed(5); phytoplankton in the waters
were responsible for the
major urea decomposition(5). In a 5-day CO2
evolution study using a
suspended soil inocula, CO2 evolution was 70.1%
in anaerobic conditions
and 66.3% in aerobic conditions(6). [(1) Freitag
D et al; Chemosphere 14:
1589-616 (1985) (2) Takemoto S et al; Suishitsu
Odaku Kenkyu 4: 80-90
(1981) (3) Atkinson R; Water Treat Exam 20:
193-203 (1971) (4) Ebisuno T
et al; Seitai Kagaku 7: 27-34 (1984) (5) Remsen
CC; Ecology 53: 921-6
(1972) (6) Scheunert I et al; Chemosphere 16:
1031-41 (1987)]**PEER
REVIEWED**
The degradation of urea was examined in a river
die-away study using
various river waters and various test
conditions(1); the degradation rate
increased with increasing temperatures; at 20 deg
C, degradation was
general complete within 6-14 days of incubation
while in some waters at
lower temperatures (4-12 deg C) little or no
degradation occurred in 10-14
days(1); below 8 deg C (simulating winter
conditions), a maximum daily
degradation of 3-6% was observed during the first
7 days of incubation(1);
depending upon the source of the water,
degradation under aerobic
conditions varied from slightly faster to more
than twice as fast as
compared to anaerobic conditions(1). In 4-day CO2
evolution tests using
waters collected from three regions of the
Pacific Ocean, CO2 evolution
was observed to occur much faster in sunlight
than in dark controls (the
ratio of light to light+dark was 61.6-86.4%)(2);
the reason for the
accelerated rate in sunlight is that urea is
actively decomposed by
photosynthesis of phytoplankton that occur in
seawater(2). [(1) Evans WH
et al; Water Res 7: 975-85 (1973) (2) Mitamura O,
Saijo Y; Marine Biology
58: 147-152 (1980)]**PEER REVIEWED**
ENVIRONMENTAL ABIOTIC DEGRADATION:
The rate constant for the vapor-phase reaction of
urea with
photochemically produced hydroxyl radicals has
been estimated to be
4X10-11 cu cm/molecule-sec at 25 deg C which
corresponds to an atmospheric
half-life of about 9.6 hr at an atmospheric concn
of 5X10+5 hydroxyl
radicals per cu cm(1,SRC). The rate constant for
the reaction between
photochemically produced hydroxyl radicals in
water and urea is reported
to be 7.9X10+5 L/mole-sec(2); assuming that the
conc of hydroxyl radicals
in brightly sunlit natural water is 1X10-17 M(3),
the half-life would be
in excess of 3000 yrs of continuous (24 hr/day)
sunlight(SRC). In one
photodegradation study using a silica gel
adsorbent(4), only 0.2% of
applied urea photomineralized after a 17-hr
irradiation with a UV lamp
( > 290 nm). [(1) Atkinson R; Environ
Toxicol Chem 7: 435-42 (1988) (2)
Buxton GV et al; J Phys Chem Ref Data 17: 727
(1988) (3) Mill T et al; Sci
207: 886-7 (1980) (4) Freitag D et al;
Chemosphere 14: 1589-616
(1985)]**PEER REVIEWED**
In aqueous solution, urea is in equilibrium with
ammonia and isocyanate
ions(1); in the absence of microorganisms, urea
hydrolyzes very slowly to
yield ammonium carbamate which decomposes to form
ammonia and carbon
dioxide(2). The hydrolysis is catalyzed by
increasing temperatures,
increasing alkalinity, and especially, by the
presence of the enzyme
urease(1); in hydrolysis studies where urease was
artificially added to
aqueous urea solutions, 20 to 50% of initial urea
hydrolyzed in 3 hr at
respective temperatures of 2 to 10 deg C(1); at 0
deg C (with added
urease), hydrolysis ranged from 25 to 100% after
24 hr at respective pHs
of 6.4 to 8.4(1). At 5 deg C in demineralized/distilled
water, only 0.35%
of added urea hydrolyzed during a 10-day test
period(3). [(1) Stiff MJ,
Gardiner DK; Water Treat Exam 22: 259-68 (1973)
(2) Mavrovic I, Shirley AR
Jr; Kirk-Othmer Encycl Chem Technol 3rd ed. NY:
John Wiley & Sons Inc
23: 548 (1983) (3) Atkinson R; Water Treat Exam
20: 193-203 (1971)]**PEER
REVIEWED**
ENVIRONMENTAL BIOCONCENTRATION:
In 6 to 72 hr bioaccumulation studies using carp
(Cyprinus carpio) and a
static flow system, the concn of urea was found
to be equally distributed
in all organs and in the water at all time
periods(1); thus, the BCF would
be only 1(SRC). In 3-day static-system tests
using golden ide fish
(Leuciscus idus melanotus), the BCF of urea was
less then 10(2). [(1)
Gluth G et al; Comp Biochem Physiol 81C: 273-7
(1985) (2) Freitag D et al;
Chemosphere 14: 1589-616 (1985)]**PEER REVIEWED**
SOIL ADSORPTION/MOBILITY:
Urea is essentially non-volatile. [Environment
Canada; Tech Info for
Problem Spills: Urea p.21 (1985)]**PEER
REVIEWED**
The adsorption of urea was measured in six
different British soils with
organic carbon contents ranging from 1.76 to
36.5%(1); no adsorption was
measurable in five of the soils(1); in the sixth
soil (36.5% organic
carbon), a KOC of 8 can be determined from the
measured Freundlich
isotherm(1,SRC); according to a suggested
classification scheme(2), a Koc
value of 8 indicates high mobility in soil(SRC).
It has been reported that
urea can adsorb to humic acids through a
free-radical addition interaction
to form a complex(3). [(1) Hance RJ; Weed Res 5:
98-107 (1965) (2) Swann
RL et al; Res Rev 85: 23 (1983) (3) Choudhry GG;
Toxicol Environ Chem 6:
127-71 (1983)]**PEER REVIEWED**
VOLATILIZATION FROM WATER/SOIL:
Based upon a measured water solubility of
5.45X10+5 mg/L(1) and an
extrapolated vapor pressure of 1.2X10-5 mm Hg at
25 deg C(2,SRC), the
Henry's Law constant for urea can be estimated to
be 1.74X10-12 atm cu
m/mole(SRC); a Henry's Law constant of this
magnitude indicates that urea
is essentially non-volatile from environmental
waters(3,SRC). [(1)
Yalkowsky SH; Arizona Database of Aqueous
Solubilities. Univ of AZ,
College of Pharmacy (1989) (2) Jones AH; J Chem
Eng Data 5: 196-200 (1960)
(3) Lyman WJ et al; Handbook of Chemical Property
Estimation Methods
Washington, DC: Amer Chem Soc pp. 15-15 to 15-29
(1990)]**PEER REVIEWED**
ENVIRONMENTAL WATER CONCENTRATIONS:
SURFACE WATER: Urea concns in surface waters off
the continental shelf
between Panama and Callao, Peru varied from
0.54-5.00 ug/L(1); along the
continental shelf of the northeast US between
Cape Cod and Cape May, urea
concn varied from a low of 0.25 ug/L (in a deep
water sample) to a high of
11.20 ug/L in New York Harbor(1). In monitoring
conducted in Mar 1971,
urea concns ranged from 36 to 535 ug/L in the
Savannah-Wilmington-Ogeechee
estuaries and adjacent coastal waters in
Georgia(2). The following urea
concns were detected in water samples collected
from three regions of the
Pacific Ocean(3): 0.85-1.43 ug/L (Sagami Bay,
Japan), 0.19-0.51 ug/L
(northwestern Pacific central waters), and
0.17-0.40 ug/L (subarctic
Pacific waters)(3). [(1) Remsen CC; Limnol
Oceanogr 16: 732-40 (1971) (2)
Remsen CC; Ecology 53: 921-6 (1972) (3) Mitamura
O, Saijo Y; Marine
Biology 58: 147-152 (1980)]**PEER REVIEWED**
EFFLUENT CONCENTRATIONS:
Contents of domestic sewage: 2-6 mg/L; domestic
sewer effluent: 0.020
mg/L; primary domestic sewage plant effluent:
0.016-0.043 mg/L
[Verschueren, K. Handbook of Environmental Data
of Organic Chemicals. 2nd
ed. New York, NY: Van Nostrand Reinhold Co.,
1983. 1178]**PEER REVIEWED**
ENVIRONMENTAL STANDARDS & REGULATIONS:
FIFRA REQUIREMENTS:
Residues of urea are exempted from the
requirement of a tolerance when
used as a stabilizer or inhibitor in accordance
with good agricultural
practices as inert (or occasionally active)
ingredients in pesticide
formulations applied to growing crops or to raw
agricultural commodities
after harvest. [40 CFR 180.1001(c)
(7/1/91)]**PEER REVIEWED**
Urea is exempted from the requirement of a
tolerance when used as a
adjuvant/intensifier for herbicides in accordance
with good agricultural
practice as inert (or occasionally active)
ingredients in pesticide
formulations applied to growing crops only. [40
CFR 180.1001(d)
(7/1/91)]**PEER REVIEWED**
Urea is exempted from the requirement of a
tolerance when used as a
stabilizer or inhibitor in accordance with good
agricultural practice as
inert (or occasionally active) ingredients in
pesticide formulations
applied to animals. [40 CFR 180.1001(e)
(7/1/91)]**PEER REVIEWED**
As the federal pesticide law FIFRA directs, EPA
is conducting a
comprehensive review of older pesticides to
consider their health and
environmental effects and make decisions about
their future use. Under
this pesticide reregistration program, EPA
examines health and safety data
for pesticide active ingredients initially
registered before November 1,
1984, and determines whether they are eligible
for reregistration. In
addition, all pesticides must meet the new safety
standard of the Food
Quality Protection Act of 1996. Pesticides for
which EPA had not issued
Registration Standards prior to the effective
date of FIFRA, as amended in
1988, were divided into three lists based upon
their potential for human
exposure and other factors, with List B
containing pesticides of greater
concern and List D pesticides of less concern.
Urea is found on List D.
Case No: 4096; Pesticide type: antimicrobial;
Case Status: No products
containing the pesticide are actively registered
... The case /is
characterized/ as "cancelled." Under
FIFRA, pesticide producers may
voluntarily cancel their registered products. EPA
also may cancel
pesticide registrations if registrants fail to
pay required fees or
make/meet certain reregistration commitments, or
if EPA reaches findings
of unreasonable adverse effects.; Active
ingredient (AI): Urea; AI Status:
The active ingredient is no longer contained in
any registered pesticide
products ... "cancelled." [USEPA/OPP;
Status of Pesticides in
Registration, Reregistration and Special Review
p.343 (Spring, 1998) EPA
738-R-98-002]**QC REVIEWED**
FDA REQUIREMENTS:
Substance added directly to human food affirmed
as generally recognized as
safe (GRAS). [21 CFR 184.1923 (4/1/91)]**PEER
REVIEWED**
ALLOWABLE TOLERANCES:
Residues of urea are exempted from the
requirement of a tolerance when
used as a stabilizer or inhibitor in accordance
with good agricultural
practices as inert (or occasionally active)
ingredients in pesticide
formulations applied to growing crops or to raw
agricultural commodities
after harvest. [40 CFR 180.1001(c)
(7/1/91)]**PEER REVIEWED**
Urea is exempted from the requirement of a
tolerance when used as a
adjuvant/intensifier for herbicides in accordance
with good agricultural
practice as inert (or occasionally active)
ingredients in pesticide
formulations applied to growing crops only. [40
CFR 180.1001(d)
(7/1/91)]**PEER REVIEWED**
Urea is exempted from the requirement of a
tolerance when used as a
stabilizer or inhibitor in accordance with good
agricultural practice as
inert (or occasionally active) ingredients in
pesticide formulations
applied to animals. [40 CFR 180.1001(e)
(7/1/91)]**PEER REVIEWED**
CHEMICAL/PHYSICAL PROPERTIES:
MOLECULAR FORMULA:
C-H4-N2-O [Budavari, S. (ed.). The Merck Index -
Encyclopedia of
Chemicals, Drugs and Biologicals. Rahway, NJ:
Merck and Co., Inc., 1989.
1553]**PEER REVIEWED**
MOLECULAR WEIGHT:
60.06 [Budavari, S. (ed.). The Merck Index -
Encyclopedia of Chemicals,
Drugs and Biologicals. Rahway, NJ: Merck and Co.,
Inc., 1989. 1553]**PEER
REVIEWED**
COLOR/FORM:
WHITE CRYSTALS [Sax, N.I. Dangerous Properties of
Industrial Materials.
6th ed. New York, NY: Van Nostrand Reinhold,
1984. 2713]**PEER REVIEWED**
TETRAGONAL PRISMS [Budavari, S. (ed.). The Merck
Index - Encyclopedia of
Chemicals, Drugs and Biologicals. Rahway, NJ:
Merck and Co., Inc., 1989.
1553]**PEER REVIEWED**
COLORLESS TO WHITE, PRISMATIC CRYSTALS OR WHITE
CRYSTALLINE POWDER [Osol,
A. and J.E. Hoover, et al. (eds.). Remington's
Pharmaceutical Sciences.
15th ed. Easton, Pennsylvania: Mack Publishing
Co., 1975. 864]**PEER
REVIEWED**
ODOR:
ALMOST ODORLESS; MAY GRADUALLY DEVELOP SLIGHT
ODOR OF AMMONIA, ESP IN
PRESENCE OF MOISTURE [Osol, A. and J.E. Hoover,
et al. (eds.). Remington's
Pharmaceutical Sciences. 15th ed. Easton,
Pennsylvania: Mack Publishing
Co., 1975. 864]**PEER REVIEWED**
TASTE:
COOLING, SALINE TASTE [Osol, A. and J.E. Hoover,
et al. (eds.).
Remington's Pharmaceutical Sciences. 15th ed.
Easton, Pennsylvania: Mack
Publishing Co., 1975. 864]**PEER REVIEWED**
Detection by taste of urea in water is as
follows: 1.20 x 10-1 m/l (purity
not specified); Taste values of chemically pure
urea: 2.51 x 10-1
moles/liter, 3.16 x 10-1 moles/liter, 3.98 x 10-1
moles/liter, 3.63 x 10-1
moles/liter, 5.01 x 10-1 moles/liter. [ASTM;
Compilation of Odor and Taste
Threshold Values Data p.162 (1978)]**PEER
REVIEWED**
MELTING POINT:
132.70 deg C [Budavari, S. (ed.). The Merck Index
- Encyclopedia of
Chemicals, Drugs and Biologicals. Rahway, NJ:
Merck and Co., Inc., 1989.
1553]**PEER REVIEWED**
DENSITY/SPECIFIC GRAVITY:
1.3230 @ 20 DEG C/4 DEG C [Lide, D.R. (ed). CRC
Handbook of Chemistry and
Physics. 72nd ed. Boca Raton, FL: CRC Press,
1991-1992.,p. 3-509]**PEER
REVIEWED**
DISSOCIATION CONSTANTS:
PKA: 0.1 @ 21 DEG C [Osol, A. and J.E. Hoover, et
al. (eds.). Remington's
Pharmaceutical Sciences. 15th ed. Easton,
Pennsylvania: Mack Publishing
Co., 1975. 864]**PEER REVIEWED**
OCTANOL/WATER PARTITION COEFFICIENT:
log Kow = -2.11 [Hansch, C., Leo, A., D. Hoekman.
Exploring QSAR -
Hydrophobic, Electronic, and Steric Constants.
Washington, DC: American
Chemical Society., 1995. 3]**QC REVIEWED**
PH:
7.2 (10% solution) [Environment Canada; Tech Info
for Problem Spills: Urea
p.4 (1985)]**PEER REVIEWED**
SOLUBILITIES:
1 G DISSOLVES IN 1 ML WATER, 10 ML 95% ALC, 6 ML
METHANOL, 1 ML BOILING
95% ALC, 20 ML ABS ALC, 2 ML GLYCEROL; ALMOST
INSOL IN CHLOROFORM, ETHER;
SOL IN CONCN HCL [Budavari, S. (ed.). The Merck
Index - Encyclopedia of
Chemicals, Drugs and Biologicals. Rahway, NJ:
Merck and Co., Inc., 1989.
1553]**PEER REVIEWED**
INSOL IN BENZENE; SOL IN ACETIC ACID [Weast, R.C.
(ed.). Handbook of
Chemistry and Physics. 60th ed. Boca Raton,
Florida: CRC Press Inc.,
1979.,p. C-536]**PEER REVIEWED**
Sol in pyrimidine [Lide, D.R. (ed). CRC Handbook
of Chemistry and Physics.
72nd ed. Boca Raton, FL: CRC Press, 1991-1992.,p.
3-509]**PEER REVIEWED**
SPECTRAL PROPERTIES:
MAX ABSORPTION (SODIUM HYDROXIDE): BELOW 220 NM;
SADTLER REF NUMBER: 447
(IR, PRISM) [Weast, R.C. (ed.). Handbook of
Chemistry and Physics. 60th
ed. Boca Raton, Florida: CRC Press Inc., 1979.,p.
C-536]**PEER REVIEWED**
IR: 123 (Sadtler Research Laboratories IR Grating
Collection) [Weast, R.C.
and M.J. Astle. CRC Handbook of Data on Organic
Compounds. Volumes I and
II. Boca Raton, FL: CRC Press Inc. 1985.,p. V2
415]**PEER REVIEWED**
UV: 1-3 (Organic Electronic Spectral Data,
Phillips et al, John Wiley
& Sons, New York) [Weast, R.C. and M.J.
Astle. CRC Handbook of Data on
Organic Compounds. Volumes I and II. Boca Raton,
FL: CRC Press Inc.
1985.,p. V2 415]**PEER REVIEWED**
NMR: 16982 (Sadtler Research Laboratories
Spectral Collection) [Weast,
R.C. and M.J. Astle. CRC Handbook of Data on
Organic Compounds. Volumes I
and II. Boca Raton, FL: CRC Press Inc. 1985.,p.
V2 415]**PEER REVIEWED**
MASS: 7 (Aldermaston, Eight Peak Index of Mass
Spectra, UK) [Weast, R.C.
and M.J. Astle. CRC Handbook of Data on Organic
Compounds. Volumes I and
II. Boca Raton, FL: CRC Press Inc. 1985.,p. V2
415]**PEER REVIEWED**
VISCOSITY:
1.78 mPas 46% solution at 20 deg C; 1.81 mPas at
137 deg C; 1.90 mPas
(saturated solution at 20 deg C) [Environment
Canada; Tech Info for
Problem Spills: Urea p.3 (1985)]**PEER REVIEWED**
OTHER CHEMICAL/PHYSICAL PROPERTIES:
ON FURTHER HEATING IT DECOMP TO BIURET, NH3,
CYANURIC ACID; PH OF 10%
WATER SOLN: 7.2; DENSITY OF WATER SOLN (WT/WT):
1.027 @ 10%; 1.054 @ 20%;
1.145 @ 50% [Budavari, S. (ed.). The Merck Index
- Encyclopedia of
Chemicals, Drugs and Biologicals. Rahway, NJ:
Merck and Co., Inc., 1989.
1553]**PEER REVIEWED**
ON STANDING OR ON HEATING, DECOMP INTO NH3 AND
CO2 [Osol, A. and J.E.
Hoover, et al. (eds.). Remington's Pharmaceutical
Sciences. 15th ed.
Easton, Pennsylvania: Mack Publishing Co., 1975.
864]**PEER REVIEWED**
Ionization potential: 9 ev [Environment Canada;
Tech Info for Problem
Spills: Urea p.4 (1985)]**PEER REVIEWED**
Latent heat of fusion: 15.1 kJ/mole (at melting
point) [Environment
Canada; Tech Info for Problem Spills: Urea p.4
(1985)]**PEER REVIEWED**
Latent heat of sublimation: 87.9 kJ/mole at 25
deg C [Environment Canada;
Tech Info for Problem Spills: Urea p.4
(1985)]**PEER REVIEWED**
Heat of formation: -333.7 kJ/mole at 25 deg C
[Environment Canada; Tech
Info for Problem Spills: Urea p.4 (1985)]**PEER
REVIEWED**
Decomposition temperature 135 deg C [Environment
Canada; Tech Info for
Problem Spills: Urea p.3 (1985)]**PEER REVIEWED**
Boiling point: urea decomposes before boiling.
[Environment Canada; Tech
Info for Problem Spills: Urea p.1 (1985)]**PEER
REVIEWED**
The possibility of improving the dissolution of
chlorthalidone (Hygroton)
via solid dispersion techniques was investigated
by means of phase
diagrams. Physical mixtures and melts of various
compositions of
chlorthalidone and urea were prepared.
Substantial increases in
dissolution rate were found for molten discs and
compressed molten discs
with a chlorthalidone concn of 35% w/w, as
compared to physical mixtures.
Urea generally enhanced dissolution in all forms.
Thermodynamic parameters
of the interaction between chlorthalidone and
urea are also reported.
[Bloch DW et al; Drugs Made Ger 25: 231-235
(1982)]**PEER REVIEWED**
The effect of urea (1), thiourea (2), niacinamide
(3), succinamide (4),
succinimide sodium (5), saccharin sodium (6),
caffeine citrate (7), ...
caffeine (8) on the solubility of
hydrochlorothiazide and chlorothiazide
in water was studied with the exception of (4),
all of the tested
compounds increased the solubility of both
diuretics. Solubility in (5),
(6), (7), and (8) was better than in (1), (2), or
(3). ... [Ammar HO et
al; Pharm Ind 43 (3): 292-295 (1981)]**PEER
REVIEWED**
1.73 kPa at 20 deg C; 5.33 kPa at 40 deg C
(saturated solutions in water)
[Environment Canada; Tech Info for Problem
Spills: Urea p.4 (1985)]**PEER
REVIEWED**
Henry's Law constant: 1.74X10-12 atm cu m/mole (est)
[SRC;; Lyman WJ et
al; Handbook of Chemical Property Estimation
Methods Washington, DC: Amer
Chem Soc pp. 15-15 to 15-29 (1990)]**PEER
REVIEWED**
CHEMICAL SAFETY & HANDLING:
SKIN, EYE AND RESPIRATORY IRRITATIONS:
Urea causes redness and irritation of skin and
eyes. [Environment Canada;
Tech Info for Problem Spills: Urea p.2
(1985)]**PEER REVIEWED**
FIRE POTENTIAL:
NONCOMBUSTIBLE [Sax, N.I. and R.J. Lewis, Sr.
(eds.). Hawley's Condensed
Chemical Dictionary. 11th ed. New York: Van
Nostrand Reinhold Co., 1987.
1209]**PEER REVIEWED**
HAZARDOUS REACTIVITIES & INCOMPATIBILITIES:
REACTS VIOLENTLY WITH GALLIUM PERCHLORATE. [Sax,
N.I. Dangerous Properties
of Industrial Materials. 5th ed. New York: Van
Nostrand Rheinhold, 1979.
467]**PEER REVIEWED**
... Urea ... /is/ excreted in human urine, react
/s/ with chlorine to form
chloramines. [Seiler, H.G., H. Sigel and A. Sigel
(eds.). Handbook on the
Toxicity of Inorganic Compounds. New York, NY:
Marcel Dekker, Inc. 1988.
229]**PEER REVIEWED**
HAZARDOUS DECOMPOSITION:
When heated to decomposition it emits toxic fumes
of nitrogen oxides.
[Sax, N.I. Dangerous Properties of Industrial
Materials. 6th ed. New York,
NY: Van Nostrand Reinhold, 1984. 2713]**PEER
REVIEWED**
PREVENTIVE MEASURES:
SRP: The scientific literature for the use of
contact lenses in industry
is conflicting. The benefit or detrimental
effects of wearing contact
lenses depend not only upon the substance, but
also on factors including
the form of the substance, characteristics and
duration of the exposure,
the uses of other eye protection equipment, and
the hygiene of the lenses.
However, there may be individual substances whose
irritating or corrosive
properties are such that the wearing of contact
lenses would be harmful to
the eye. In those specific cases, contact lenses
should not be worn. In
any event, the usual eye protection equipment
should be worn even when
contact lenses are in place. **PEER REVIEWED**
CLEANUP METHODS:
Water Spill: Contain by damming, water diversion
or natural barriers.
Remove and treat contaminated liquids. Absorb
small amounts of liquid
spill with natural or synthetic sorbents, shovel
into containers and
cover. [Environment Canada; Tech Info for Problem
Spills: Urea p.2
(1985)]**PEER REVIEWED**
If urea is spilled in solid form, shovel material
into containers and
cover. Construct barriers to contain solutions or
divert to impermeable
holding area. Remove material by manual or
mechanical means. [Environment
Canada; Tech Info for Problem Spills: Urea p.1
(1985)]**PEER REVIEWED**
DISPOSAL METHODS:
Urea is a waste chemical stream constituent which
may be subjected to
ultimate disposal by controlled incineration.
Incinerator is equipped with
a scrubber or thermal unit to reduce nitrogen
oxide emissions. [USEPA;
Engineering Handbook for Hazardous Waste
Incineration p.2-10 (1981) EPA
68-03-3025]**PEER REVIEWED**
The following wastewater treatment technology has
been investigated for
urea: Concentration process: Biological
treatment. [USEPA; Management of
Hazardous Waste Leachate, EPA Contract
No.68-03-2766 p.E-36 (1982)]**PEER
REVIEWED**
OCCUPATIONAL EXPOSURE STANDARDS:
OTHER OCCUPATIONAL PERMISSIBLE LEVELS:
Workplace Environmental Exposure Level (WEEL):
8-hr Time-weighted Average
(TWA) 10 mg/cu m. [American Industrial Hygiene
Association. The AIHA 1999
Emergency Response Planning Guidelines and
Workplace Environmental
Exposure Level Guides Handbook.American
Industrial Hygiene Association.
Fairfax, VA 1999. 41]**QC REVIEWED**
MANUFACTURING/USE INFORMATION:
MAJOR USES:
The active ingredient is no longer contained in
any registered pesticide
products ... "cancelled." [USEPA/OPP;
Status of Pesticides in
Registration, Reregistration and Special Review
p.343 (Spring, 1998) EPA
738-R-98-002]**QC REVIEWED**
MFR OF RESINS & PLASTICS; CONDENSED WITH
MALONIC ESTER TO FORM
BARBITURIC ACID; CELLULOSE SOFTENER; IN
AMMONIATED DENTIFRICES. [Budavari,
S. (ed.). The Merck Index - Encyclopedia of
Chemicals, Drugs and
Biologicals. Rahway, NJ: Merck and Co., Inc.,
1989. 1553]**PEER REVIEWED**
CHEMICAL INTERMEDIATE; STABILIZER IN EXPLOSIVES;
IN MEDICINE (DIURETIC);
SEPARATION OF HYDROCARBONS; SULFAMIC ACID
PRODUCTION; FLAMEPROOFING
AGENTS. [Sax, N.I. and R.J. Lewis, Sr. (eds.).
Hawley's Condensed Chemical
Dictionary. 11th ed. New York: Van Nostrand
Reinhold Co., 1987.
1209]**PEER REVIEWED**
LIQUID & OTHER FERTILIZER APPLICATIONS;
LIVESTOCK NUTRIENT; MONOMER
FOR UREA-FORMALDEHYDE RESINS; CHEMICAL
INTERMEDIATE FOR MELAMINE
[SRI]**PEER REVIEWED**
Incorporation of high concentrations of
urea > 300 g/l in a print paste
greatly accelerates the fixation of low molecular
weight dyes on wool.
[Kirk-Othmer Encyclopedia of Chemical Technology.
3rd ed., Volumes 1-26.
New York, NY: John Wiley and Sons, 1978-1984.,p.
V24 612 (1984)]**PEER
REVIEWED**
UREA HAS BEEN USED AS AN INSECT (MOSQUITO)
REPELLENT. [HILL JA ET AL; MOSQ
NEWS 39 (2): 307-310 (1979)]**QC REVIEWED**
45% urea solutions are used in dentifrices [Kirk-Othmer
Encyclopedia of
Chemical Technology. 3rd ed., Volumes 1-26. New
York, NY: John Wiley and
Sons, 1978-1984.,p. V7 522 (1979)]**PEER
REVIEWED**
Urea is dehydrated and condensed to produce
melamine [Kirk-Othmer
Encyclopedia of Chemical Technology. 3rd ed.,
Volumes 1-26. New York, NY:
John Wiley and Sons, 1978-1984.,p. V7 303
(1979)]**PEER REVIEWED**
Urea is a decomposition inhibitor for ammonium
perchlorate [Kirk-Othmer
Encyclopedia of Chemical Technology. 3rd ed.,
Volumes 1-26. New York, NY:
John Wiley and Sons, 1978-1984.,p. V5 650
(1979)]**PEER REVIEWED**
Urea is reacted with alcohols to form
alkylcarbamates [Kirk-Othmer
Encyclopedia of Chemical Technology. 3rd ed.,
Volumes 1-26. New York, NY:
John Wiley and Sons, 1978-1984.,p. V4 475
(1978)]**PEER REVIEWED**
Urea is a building block for amino resins [Kirk-Othmer
Encyclopedia of
Chemical Technology. 3rd ed., Volumes 1-26. New
York, NY: John Wiley and
Sons, 1978-1984.,p. V2 442 (1978)]**PEER
REVIEWED**
Urea is reacted with fatty acids from coconut oil
to produce amides in 90%
yields [Kirk-Othmer Encyclopedia of Chemical
Technology. 3rd ed., Volumes
1-26. New York, NY: John Wiley and Sons,
1978-1984.,p. V2 253
(1978)]**PEER REVIEWED**
Urea is used with zinc formaldehyde sulfoxylate
to remove permanent hair
dye [Kirk-Othmer Encyclopedia of Chemical
Technology. 3rd ed., Volumes
1-26. New York, NY: John Wiley and Sons,
1978-1984.,p. V12 109
(1980)]**PEER REVIEWED**
Urea is reacted with alpha-diketones or
dialdehydes to form hydantoins
[Kirk-Othmer Encyclopedia of Chemical Technology.
3rd ed., Volumes 1-26.
New York, NY: John Wiley and Sons, 1978-1984.,p.
V12 702 (1980)]**PEER
REVIEWED**
Urea is used to partially reverse the
methylolamine chain reaction in glue
gellation processes [Kirk-Othmer Encyclopedia of
Chemical Technology. 3rd
ed., Volumes 1-26. New York, NY: John Wiley and
Sons, 1978-1984.,p. V11
913 (1980)]**PEER REVIEWED**
Urea and phosphoric acid mixtures impart flame
resistance to cotton
fabrics [Kirk-Othmer Encyclopedia of Chemical
Technology. 3rd ed., Volumes
1-26. New York, NY: John Wiley and Sons,
1978-1984.,p. V10 421
(1980)]**PEER REVIEWED**
Concentrated urea solutions are used to promote
the rate of reaction
between reactive dyes and wools [Kirk-Othmer
Encyclopedia of Chemical
Technology. 3rd ed., Volumes 1-26. New York, NY:
John Wiley and Sons,
1978-1984.,p. V8 387 (1979)]**PEER REVIEWED**
Urea is used as a moisture resistant paper
additive [Kirk-Othmer
Encyclopedia of Chemical Technology. 3rd ed.,
Volumes 1-26. New York, NY:
John Wiley and Sons, 1978-1984.,p. V16 791
(1981)]**PEER REVIEWED**
Ammonolysis of urea and ammonium thiocyanate
produces guanidine
[Kirk-Othmer Encyclopedia of Chemical Technology.
3rd ed., Volumes 1-26.
New York, NY: John Wiley and Sons, 1978-1984.,p.
S 519 (1984)]**PEER
REVIEWED**
Urea is used as a deicing compound on airport
runways [Kirk-Othmer
Encyclopedia of Chemical Technology. 3rd ed.,
Volumes 1-26. New York, NY:
John Wiley and Sons, 1978-1984.,p. V21 219
(1983)]**PEER REVIEWED**
Formulation and fermentation aid in yeast-raised
bakery products,
alcoholic beverages, and gelatin products. [21
CFR 184.1923
(4/1/91)]**PEER REVIEWED**
Urea and other organic and inorganic sources of
nitrogen such as biuret
and ammonium phosphate are added to ruminant
rations as a source of
nonprotein nitrogen. However, urea is the most
widely used. It is also
used as a fertilizer and a substitute for salts
in melting of snow and ice
in residential areas. [Booth, N.H., L.E. McDonald
(eds.). Veterinary
Pharmacology and Therapeutics. 5th ed. Ames,
Iowa: Iowa State University
Press, 1982. 1029]**PEER REVIEWED**
MEDICATION **QC REVIEWED**
MANUFACTURERS:
Agricultural Minerals Corp, Hq, 5100 E Skelly
Drive, Suite 800, Tulsa, OK
74135-6549, (918) 660-0050, (800) 523-9083;
Production site: Blytheville,
AK 72319; Verdigris, OK 74015 [SRI. 1992
Directory of Chemical
Producers-United States of America. Menlo Park,
CA: SRI International,
1992. 1045]**PEER REVIEWED**
Air Products and Chemicals, Inc, Hq, 7201
Hamilton Blvd, Allentown, PA
18195-1501, (215) 481-4911; Chemicals Group (800)
345-3148; Industrial
Chemicals Division; Production site: Pace, FL
32571 [SRI. 1992 Directory
of Chemical Producers-United States of America.
Menlo Park, CA: SRI
International, 1992. 1045]**PEER REVIEWED**
American Cyanamid Company, Hq, One Cyanamid
Plaza, Wayne, NJ 07470, (201)
831-2000; Chemical Products Division; Production
site: Fortier Plant,
Avondale, LA 70094 [SRI. 1992 Directory of
Chemical Producers-United
States of America. Menlo Park, CA: SRI
International, 1992. 1045]**PEER
REVIEWED**
Arcadian Corp, Hq, 6750 Poplar Avenue, Suite 600,
Memphis, TN 38138-7419,
(901) 758-5200; Production sites: Augusta, GA
30903; Clinton, IA 52732;
Geismar, LA 70734; Lake Charles, LA 70602; La
Platte, NE 68005; Memphis,
TN 38127 [SRI. 1992 Directory of Chemical
Producers-United States of
America. Menlo Park, CA: SRI International, 1992.
1045]**PEER REVIEWED**
Borden Chemicals and Plastics Partnership, Hq,
Highway 73, Geismar, LA
70734, (504) 387-5101; Production site: Geismar,
LA 70734 [SRI. 1992
Directory of Chemical Producers-United States of
America. Menlo Park, CA:
SRI International, 1992. 1045]**PEER REVIEWED**
BP America, Inc, Hq, 200 Public Sq, Cleveland, OH
44114-2375, (216)
586-4141; Subsidiary: BP Chemicals America, Inc;
Production site: Lima, OH
45802 [SRI. 1992 Directory of Chemical
Producers-United States of America.
Menlo Park, CA: SRI International, 1992.
1046]**PEER REVIEWED**
CF Industries, Inc, Hq, Salem Lake Dr, Long
Grove, IL 60047, (312)
438-9500; Production site: Donaldsonville, LA
70346 [SRI. 1992 Directory
of Chemical Producers-United States of America.
Menlo Park, CA: SRI
International, 1992. 1046]**PEER REVIEWED**
Chevron Corporation, Hq, 225 Bush St, San
Francisco, CA 94104, (415)
894-7700; Subsidiarie: Chevron Chemical Company;
Chevron Fertilizer
Division, 6001 Bolinger Canyon Rd, San Ramon, CA
94583-0947; Production
site: St Helens, OR 97051 [SRI. 1992 Directory of
Chemical
Producers-United States of America. Menlo Park,
CA: SRI International,
1992. 1046]**PEER REVIEWED**
The Coastal Corp, Hq, Coastal Tower, 9 Greenway
Plaza, Houston, TX
77046-0995, (713) 877-1400; Subsidiary: Coastal
Chem, Inc; Productions
site: Cheyeme, WY 82003 [SRI. 1992 Directory of
Chemical Producers-United
States of America. Menlo Park, CA: SRI
International, 1992. 1046]**PEER
REVIEWED**
Cominco American Inc, Hq, 601 West Riverside,
Spokane, WA 99201, (509)
747-6111; Cominco Fertilizers Division;
Production site: Borger, TX 79008
[SRI. 1992 Directory of Chemical Producers-United
States of America. Menlo
Park, CA: SRI International, 1992. 1046]**PEER
REVIEWED**
Farmland Industries, Inc, Hq, 3315 North Oak
Trafficway, PO Box 7305,
Kansas City, MO 64116, (816) 459-6000; Production
sites: Beatrice, NE
68310; Dodge City, KS 67801; Enid, OK 73702;
Lawrence, KS 66044 [SRI. 1992
Directory of Chemical Producers-United States of
America. Menlo Park, CA:
SRI International, 1992. 1046]**PEER REVIEWED**
Freeport-McMoRan Resource Partners, Hq, 1615
Poydras, New Orleans, LA
70112, (504) 582-4000; Agrico Chemical Co, PO Box
60031; New Orleans, LA
70160; Production site: Donaldsonville, LA 70346
[SRI. 1992 Directory of
Chemical Producers-United States of America.
Menlo Park, CA: SRI
International, 1992. 1046]**PEER REVIEWED**
Inspiration Resources Corporation, Hq;
Subsidiary: Terra International,
Inc, Terra Centre, 600 Fourth St, Sioux City, IA
51101, (712) 277-1340;
Production site: Sergeant Bluff, IA 51054 [SRI.
1992 Directory of Chemical
Producers-United States of America. Menlo Park,
CA: SRI International,
1992. 1046]**PEER REVIEWED**
La Roche Holdings Inc, Hq, La Roche Industries,
Inc, Perimeter 400 Center,
1100 Johnson Ferry Rd NE, Atlanta, GA 30342,
(404) 851-0300; Production
site: Cherokee, AL 35616 [SRI. 1992 Directory of
Chemical Producers-United
States of America. Menlo Park, CA: SRI
International, 1992. 1046]**PEER
REVIEWED**
Mississippi Chemical Corporation, Hq, PO Box 388,
Yazoo City, MS 39194,
(601) 746-4131; Production site: Yazoo City, MS
39194 [SRI. 1992 Directory
of Chemical Producers-United States of America.
Menlo Park, CA: SRI
International, 1992. 1046]**PEER REVIEWED**
Nitrogen Products, Inc, Hq, PO Box 825, Helena,
AR 72342, (501) 338-9111;
Production site: Helena, AR 72342 [SRI. 1992
Directory of Chemical
Producers-United States of America. Menlo Park,
CA: SRI International,
1992. 1046]**PEER REVIEWED**
Triad Chemical, Hq, PO Box 388, Yazoo City, MS
39194, (601) 746-4131;
Production site: Donaldsonville, LA 70346 [SRI.
1992 Directory of Chemical
Producers-United States of America. Menlo Park,
CA: SRI International,
1992. 1046]**PEER REVIEWED**
Unocal Corp, Hq, 1201 West Fifth St, PO Box 7600,
Los Angeles, CA 90051,
(213) 977-7600; Unocal Minerals and Chemicals
Division; Agricultural
Products Group; Production site: Kenai, AK 99611
[SRI. 1992 Directory of
Chemical Producers-United States of America.
Menlo Park, CA: SRI
International, 1992. 1046]**PEER REVIEWED**
The Vigoro Corporation, Hq, 225 N Michigan Ave,
Suite 2416, Chicago, IL
60601, (312) 819-2020; Phoenix Chemical Company,
11675 Highway 20 West, PO
Box 229, East Dubuque, IL 61025-0229; Production
site: East Dubuque, IL
61025-0229 [SRI. 1992 Directory of Chemical
Producers-United States of
America. Menlo Park, CA: SRI International, 1992.
1046]**PEER REVIEWED**
Willard Feed and Grain, Hq, Route 2, Box 41,
Celina, TX 75009, (214)
382-2367; Wil-Gro Fertilizer, Inc, division,
Pryor, OK 74362 [SRI. 1992
Directory of Chemical Producers-United States of
America. Menlo Park, CA:
SRI International, 1992. 1046]**PEER REVIEWED**
Columbia Nitrogen Corporatin, Hq, PO Box 1483,
Augusta, GA 30903, (404)
823-4300 [United States International Trade
Commission. Synthetic Organic
Chemicals-United States Production and Sales,
1989. USITC Publication
2338, 1990. Washington, DC:United States
International Trade Commission,
1990.,p. 14-10]**PEER REVIEWED**
Mississippi Chemical Corporation, Hq, PO Box 388,
Yazoo City, MS 39194,
(601) 746-4131 [United States International Trade
Commission. Synthetic
Organic Chemicals-United States Production and
Sales, 1989. USITC
Publication 2338, 1990. Washington, DC:United
States International Trade
Commission, 1990.,p. 14-10]**PEER REVIEWED**
Olin Corporation, Hq, 120 Long Ridge Road,
Stanford, CT 06904, (203)
354-2000 [United States International Trade
Commission. Synthetic Organic
Chemicals-United States Production and Sales,
1989. USITC Publication
2338, 1990. Washington, DC:United States
International Trade Commission,
1990.,p. 14-10]**PEER REVIEWED**
JR Simplot Company, Hq, PO Box 912, Pocatello, ID
83204, (208) 336-2110
[United States International Trade Commission.
Synthetic Organic
Chemicals-United States Production and Sales,
1989. USITC Publication
2338, 1990. Washington, DC:United States
International Trade Commission,
1990.,p. 14-10]**PEER REVIEWED**
Triad Chemical, Hq, PO box 310, Donaldsonville,
LA 70346, (504) 473-9231
[United States International Trade Commission.
Synthetic Organic
Chemicals-United States Production and Sales,
1989. USITC Publication
2338, 1990. Washington, DC:United States
International Trade Commission,
1990.,p. 14-10]**PEER REVIEWED**
Tennessee Valley Authority, Hq, Muscle Shoals, AL
35660, (205) 386-3521;
Division of Developmental Production [United
States International Trade
Commission. Synthetic Organic Chemicals-United
States Production and
Sales, 1989. USITC Publication 2338, 1990.
Washington, DC:United States
International Trade Commission, 1990.,p.
14-10]**PEER REVIEWED**
Union Oil Company of California, 1201 W Fifth
Street, Los Angeles, Ca
90017, (213) 977-5131 [United States
International Trade Commission.
Synthetic Organic Chemicals-United States
Production and Sales, 1989.
USITC Publication 2338, 1990. Washington,
DC:United States International
Trade Commission, 1990.,p. 14-10]**PEER
REVIEWED**
METHODS OF MANUFACTURING:
DEHYDRATION OF AMMONIUM CARBONATE WHICH IS
SYNTHESIZED FROM AMMONIA AND
CARBON DIOXIDE. [SRI]**PEER REVIEWED**
... FROM AMMONIA, CARBON MONOXIDE &
SULFUR IN METHANOL. [Budavari, S.
(ed.). The Merck Index - Encyclopedia of
Chemicals, Drugs and Biologicals.
Rahway, NJ: Merck and Co., Inc., 1989.
1553]**PEER REVIEWED**
LIQ AMMONIA & LIQ CARBON DIOXIDE @
1750-3000 PSI & 160-200 DEG C
REACT TO FORM AMMONIUM CARBAMATE, NH4CO2NH2,
WHICH DECOMP @ LOWER PRESSURE
(ABOUT 80 PSI) TO UREA & WATER. METHOD OF
PURIFICATION:
CRYSTALLIZATION. [Sax, N.I. and R.J. Lewis, Sr.
(eds.). Hawley's Condensed
Chemical Dictionary. 11th ed. New York: Van
Nostrand Reinhold Co., 1987.
1209]**PEER REVIEWED**
GENERAL MANUFACTURING INFORMATION:
OCCURS IN URINE & OTHER BODY FLUIDS.
FIRST ORG CMPD TO BE SYNTHESIZED
... [Sax, N.I. and R.J. Lewis, Sr. (eds.).
Hawley's Condensed Chemical
Dictionary. 11th ed. New York: Van Nostrand
Reinhold Co., 1987.
1209]**PEER REVIEWED**
PURE UREA SHOULD NOT GIVE THE BIURET REACTION
UNLESS HEATED ABOVE MELTING
POINT. IN PRACTICE ALL REAGENT GRADE UREA GIVES
POSITIVE BIURET REACTION.
[Budavari, S. (ed.). The Merck Index -
Encyclopedia of Chemicals, Drugs
and Biologicals. Rahway, NJ: Merck and Co., Inc.,
1989. 1553]**PEER
REVIEWED**
&nb