EXTOXNET PIP - PROPOXUR
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Revised June 1996
Propoxur
Trade and Other Names:
Trade and other names for propoxur include Arprocarb, Bay 9010,
Baygon, Bayer 39007, Bifex, Blattanex, Brifur, Bolfo, BO Q
5812315, ENT 25671, Invisi-Gard, OMS 33, PHC, Pillargon, Prentox
Carbamate, Propogon, Proprotox, Propyon, Rhoden, Sendran,
Suncide, Tendex, Tugen, Unden, and Undene.
Regulatory Status:
Propoxur is a highly toxic compound; various formulations are in
diffferent EPA toxicity classes. It is a General Use Pesticide
(GUP), although some formulations may be for professional use
only. Labels for pesticide products containing Propoxur must bear
the Signal Word DANGER, WARNING or CAUTION, depending on the
formulation.
Chemical Class:
carbamate
Introduction:
Propoxur is a non-systemic insecticide which was introduced in
1959. It is compatible with most insecticides and fungicides
except alkalines, and may be found in combination with
azinphosmethyl, chlorpyrifos, cyfluthrin, dichlorvos, disulfoton,
or methiocarb. It is used on a variety of insect pests such as
chewing and sucking insects, ants, cockroaches, crickets, flies,
and mosquitoes, and may be used for control of these in
agricultural or (as Baygon) in non-agricultural (e.g. private or
public facilities and grounds) applications. Agricultural
applications include cane, cocoa, fruit, grapes, maize, rice,
sugar, vegetables, cotton, lucerne, forestry, and ornamentals. It
has contact and stomach action that is long-acting when it is in
direct contact with the target pest. Propoxur is available in
several types of formulations and products, including
emulsifiable concentrates, wettable powders, baits, aerosols,
fumigants, granules, and oilsprays.
Formulation: Propoxur
is available in several types of formulations and products,
including emulsifiable concentrates, wettable powders, baits,
aerosols, fumigants, granules, and oilsprays. Toxicological Effects:
- Acute toxicity: Propoxur is highly toxic
via the oral route, with reported LD50 values of
approximately 100 mg/kg in rats and mice [10]. An oral
LD50 of 40 mg/kg is reported for guinea pigs [5].
Propoxur is only slightly toxic via the dermal route,
with reported dermal LD50 values of 1000 mg/kg to greater
than 2400 mg/kg in rats, and greater than 500 mg/kg in
rabbits [5]. Tests show that propoxur does not cause skin
or eye irritation in rabbits [10]. Via the inhalation
route, it is also slightly toxic, with a reported 1-hour
inhalation LC50 of greater than 1.44 mg/L [10]. Like
other carbamates, propoxur can inhibit the action of
cholinesterase and disrupt nervous system function.
Depending on the severity of exposure, this effect may be
short-term and reversible [5]. Signs of propoxur
intoxication can include nausea, vomiting, abdominal
cramps, sweating, diarrhea, excessive, salivation,
weakness, imbalance, blurring of vision, breathing
difficulty, increased blood pressure, incontinence, or
death [5]. In rats, propoxur poisoning resulted in brain
pattern and learning ability changes at lower
concentrations than those which caused
cholinesterase-inhibition and/or organ weight changes
[8]. During wide-scale spraying of propoxur in malarial
control activities conducted by the World Health
Organization (WHO), only mild cases of poisoning were
noted. Applicators who used propoxur regularly showed a
pronounced daily fall in whole blood cholinesterase
activity and a distinct recovery after exposure stopped.
No adverse cumulative effects on cholinesterase activity
were demonstrated [8]. Human adults have ingested single
doses of 50 mg of propoxur without apparent symptoms [5].
- Chronic toxicity: Prolonged or repeated
exposure to propoxur may cause symptoms similar to acute
effects. Propoxur is very efficiently detoxified
(transformed into less toxic or practically nontoxic
forms), thus making it possible for rats to tolerate
daily doses approximately equal to the LD50 of the
insecticide for long periods, provided that the dose is
spread out over the entire day, rather than ingested all
at once [5].
- Reproductive effects: In female rats
given high dietary doses of approximately 18 mg/kg/day of
propoxur as a part of a three-generation reproduction
study, reduced parental food consumption, growth,
lactation, and litter size were observed [5]. At 25
mg/kg/day administered to pregnant rats there was a
decrease in the number of offspring [5]. Dietary doses of
approximately 2.25 mg/kg/day did not affect fertility,
litter size, or lactation, but parental food intake and
growth were depressed in the exposed group [5]. This
evidence suggest that reproductive effects in humans are
unlikely at expected exposure levels.
- Teratogenic effects: Offspring of female
rats fed 5 mg/kg/day of propoxur during gestation and
weaning exhibited reduced birth weight, retarded
development of some reflexes, and evidence of central
nervous system impairment [5]. In another rat study,
growth reduction was observed in the offspring of
pregnant rats given doses of 3, 9 and 30 mg/kg/day, but
no other physiological or anatomical abnormalities were
observed. The evidence suggests that teratogenic effects
will only occur at high doses.
- Mutagenic effects: Propoxur did not
cause mutations in six different types of bacteria [46].
The evidence indicates that propoxur is not mutagenic.
- Carcinogenic effects: No carcinogenic
effects have been reported for propoxur [5].
- Organ toxicity: As determined in animal
tests and data from human autopsies in poisoned
individuals, the nervous system, and liver are the organs
principally affected by propoxur [5,46].
- Fate in humans and animals: Propoxur is
broken down and excreted rapidly in urine [5]. In humans
given a single oral dose of 92.2 mg of Baygon, 38% of the
dose was excreted in urine over the first 24 hours, with
most of it excreted in the first 8 to 10 hours [5].
Carbamates generally are excreted rapidly and do not
accumulate in mammalian tissue [5].
Ecological Effects:
- Effects on birds: Propoxur is very
highly to highly toxic to many bird species, but its
toxicity varies by the species. The reported LD50 is 25.9
mg/kg in bobwhite quail [10]. Other reported oral LD50
values (for a 97 to 98% technical grade propoxur
product), are 4 mg/kg in mourning doves and house
finches, 6 mg/kg in Canada geese, 10.5 mg/kg in mallards,
20 mg/kg in pheasants, 26 mg/kg and 28 mg/kg in
California and Japanese quail respectively and 120 mg/kg
in grouse [17]. The 5-day dietary LC50 for Japanese quail
is greater than 5000 ppm [10]. Acute symptoms of propoxur
poisoning in birds include eye tearing, salivation,
muscle incoordination, diarrhea, and trembling [47].
Depending on the type of bird, poisoning signs can appear
within 5 minutes of exposure, with deaths occurring
between 5 and 45 minutes, or overnight. Symptoms in
survivors disappeared from 90 minutes to several days
after treatment [47].
- Effects on aquatic organisms: Propoxur is moderately to
slightly toxic to fish and other aquatic species. The
reported 96-hour LC50 values are 3.7 mg/L in rainbow
trout, and 6.6 mg/L in bluegill sunfish [10]. The oral
LD50 for propoxur in bullfrogs is 595 mg/kg [17]. The
compound is not expected to accumulate significantly in
aquatic organisms. The calculated accumulation factor for
propoxur is nine times the ambient water concentration.
- Effects on other organisms: Propoxur is
highly toxic to honeybees [10]. The oral LD50 for
propoxur in mule deer is 100 to 350 mg/kg [17].
Environmental Fate:
- Breakdown in soil and groundwater:
Propoxur is of moderate to low persistence in the soil
environment, with reported field half-lives of 14 to 50
days [13]. It has a low affinity for soil binding, and so
may be mobile in many soils [13]. Because it is highly
soluble in water, is moderately persistent, and does not
adsorb strongly to soil particles, propoxur has a high
potential for groundwater penetration [14,48]. In one
study, there was practically no loss of propoxur from a
silt-loam soil to which it was applied during a 6-month
period, but 25% of applied Baygon was lost from sand in
100 days [48]. In another study, propoxur was very mobile
in sandy loam, silt loam and silty clay soils. The rate
of biodegradation in soil increases in soils that have
been previously exposed to propoxur or other
methylcarbamate pesticides [48].
- Breakdown in water: Propoxur hydrolyzes,
or breaks down in water, at a rate of 1.5% per day in a
1% aqueous solution at pH of 7.0 [48].
- Breakdown in vegetation: Propoxur can
enter the roots of a plant and travel to the leaves,
where it can then poison insects that feed on the leaves,
and can have residual activity of up to 1 month when
applied to plant surfaces [8].
Physical Properties:
- Appearance: Technical propoxur is a
white to cream-colored crystalline solid.
- Chemical Name: 2-isopropoxyphenyl
methylcarbamate [10]
- CAS Number: 114-26-1
- Molecular Weight: 209.25
- Water Solubility: 2000 mg/L @ 20 C [10]
- Solubility in Other Solvents: Soluble in
most polar organic solvents, e.g, acetone, methanol,
cyclohexanone, chloroform, and toluene [10]
- Melting Point: 84-87 C [10]
- Vapor Pressure: 300 mPa @ 120 C [10]
- Partition Coefficient: 0.14 [48]
- Adsorption Coefficient: 30 [13]
Exposure Guidelines:
- ADI: 0.02 mg/kg/day [10]
- MCL: Not Available
- RfD: Not Available
- PEL: 0.5 mg/m3 (8-hour) [31]
- HA: 0.003 mg/L [48]
- TLV: Not Available
Basic Manufacturer:
Atomergic Chemetals Corp.
222 Sherwood Avenue
Farmingdale, NY 11735-1718
- Phone: 516-694-9000
- Emergency: 800-424-9300
References:
References for the information in this PIP can be found in
Reference List Number 3
DISCLAIMER: The
information in this profile does not in any way replace or
supersede the information on the pesticide product labeling or
other regulatory requirements. Please refer to the pesticide
product labeling.
