E X T O X N E T
Extension Toxicology
Network
Pesticide Information Profiles
A Pesticide Information Project of Cooperative Extension Offices of Cornell
University, Oregon State University, the University of Idaho, and the University
of California at Davis and the Institute for Environmental Toxicology, Michigan
State University. Major support and funding was provided by the USDA/Extension
Service/National Agricultural Pesticide Impact Assessment Program.
EXTOXNET primary files maintained and archived at Oregon State University
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.
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