E X T O X N E T
Extension Toxicology Network
A Pesticide Information Project of Cooperative Extension Offices of
Cornell University, Michigan State University, Oregon State University, and
University of California at Davis. Major support and funding was provided
by the USDA/Extension Service/National Agricultural Pesticide Impact
Publication Date: 9/95
TRADE AND OTHER NAMES
Trade names for products containing carbophenothion include Trithion,
Garrathion, Dagadip, R-1303(1), Endyl, Lethox (2), Nephocarp, Acarithion, and
Carbophenothion is a Restricted Use Pesticide (RUP). It is for retail
sale to and use only by certified applicators or people directly supervised by
them. The EPA requires a 2-day safety waiting interval between application
and worker reentry to fields to prevent unnecessary skin exposure (1, 4).
Carbophenothion is an insecticide and acaricide (1, 2). A member of the
organo-phosphate class of chemicals, it has a long residual activity. For this
reason, it is effective against the eggs and recently hatched young of many
species (6). It affects insects on contact and when consumed. It is used on
citrus fruit and cotton to control aphids and spider mites. When combined with
petroleum oil, it controls over-wintering mites, aphids, and scale bugs (8,
9). It is also used to control aphids, mites, suckers, and other pests on
fruit, nuts, vegetables, sorghum, maize, and others. It is used to control
parasites on animals. Carbophenothion is available as an emulsifiable
concentrate, wettable powder, granules, and a seed treatment (9). The EPA has
classified carbophenothion as Category I - highly toxic. Products containing
the active ingredient bear the SIGNAL WORD: DANGER (5). Carbophenothion may
enhance the toxicity of malathion and some other compounds which are processed
into more toxic forms by living organisms (10).
Carbophenothion affects the nervous system by inhibiting chlolinesterase
(3). Symptoms of poisoning include headache, blurred vision, weakness, nausea,
discomfort in the chest, abdominal cramps, vomiting, diarrhea, salivation,
sweating and pinpoint pupils (12, 16). It is highly toxic when eaten and
nearly as toxic when absorbed through the skin.
The LD50, the dose of carbophenothion which kills half of the study
animals who eat it, is 10 mg/kg for female rats, 30 mg/kg for male rats and
218 mg/kg for mice (9). The LD50 for skin exposure to carbophenothion is 27
mg/kg for female rats, 54 mg/kg for male rats, and 1,270 to 1,850 mg/kg for
rabbits (8, 9, 11). The LC50, the concentration at which half of the test rats
die by inhaling carbophenothion is 0.002 mg/l of air (14). Carbophenothion
causes irritation to rabbit eyes, but symptoms clear within days (14).
A three generation study showed that a dose of 1-2 mg/kg/day of
carbophenothion in the diet caused reduced birth weight, increased
stillbirths, and a decreased survival to weaning in rats (7). The level at
which it has no observable effect (NOEL) on reproduction is 0.5 mg/kg/day (4).
The lowest dose which had an effect on reproduction (LEL) is 1.5 mg/kg/day. At
this level, rat pups' survival decreased and they weighed less than normal
Carbophenothion is not teratogenic (7).
No information is available. However, since carbophenothion is an
organophosphate compound and most organophosphate compounds are not mutagenic,
it is unlikely to be mutagenic (10).
A two-year feeding study of rats showed that a dose of 4 mg/kg/day of
carbophenothion, the highest dose tested, did not cause tumors (14).
As a cholinesterase inhibitor, carbophenothion affects the activity of
nerves and the brain (9, 10). Studies have shown that carbophenothion may also
cause some reduction in the number of red blood cells and increased adrenal
gland weights in females (10).
Fate in Humans and Animals
Carbophenothion is absorbed through the skin very quickly. It penetrates
rat skin in less than an hour (8). It is excreted from the body rapidly. The
majority is excreted in urine and feces within 72 hours. Almost none is
retained in tissue (15).
Effects on Birds
Carbophenothion is highly toxic to many birds (3). The LD50 is 5.6 mg/kg
for European starlings, 29-35 mg/kg for the Canada goose, 121 mg/kg for
mallard ducks, and 56.8 for Japanese quail. The LC50 for Japanese quail who
consume carbophenothion in their diet is 4,434 ppm (8).
Effects on Aquatic Organisms
Carbophenothion is highly toxic to fish, crustaceans, marine organisms
and amphibians (3, 6). The LD50 is 56 ppb for rainbow trout and 13 ppb for
bluegill sunfish, 0.47 ppb for pink shrimp and 17 ppb for sheepshead minnow.
Preliminary data show that Carbophenothion may accumulate in some species of
Effects on Others (Nontarget species)
Carbophenothion is highly toxic to bees. It is also highly toxic to
wildlife, including upland game birds (3, 4). Leaf damage may occur to
Delicious apples and injury also has been reported on grapefruit, kumquat, and
citron from exposure to carbophenothion. It may injure ferns and a few
sensitive rose varieties, especially in warm, moist conditions (6, 9).
Breakdown of Chemical in Soil and Groundwater
Carbophenothion persists in soils for longer than 6 months (8).
Preliminary data indicate that it is relatively immobile in sandy loam soils
Breakdown of Chemical in Surface Water
No information currently available.
Breakdown of Chemical in Vegetation
A ten day waiting period between treatment with carbophenothion and
application of dinitro compounds is recommended because the combination may
damage plant leaves (6).
PHYSICAL PROPERTIES AND GUIDELINES
Carbophenothion in the pure form is a yellow-brown liquid with a mild
mercaptan-like odor. It is non-corrosive and relatively stable to hydrolysis
and to temperatures up to 80 degrees C (9).
|CAS #: ||786-19-6
|Chemical Name: ||S-[[(p-chlorophenyl)thio] methyl] O,O-diethyl phosphorodithioate
|Water solubility: ||0.34 ppm at 20 degrees C (8)
|Solubility in other solvents: ||Miscible in most organic solvents including alcohols, ethers, toluene, benzene, xylene, ketones, and mineral and vegetable oils (9)
|Boiling point: ||82 degrees C
|ADI: ||0.0125 mg/kg/day (13)
|NOEL: ||1.1 mg/kg/day (rat)(13)
ICI Americas, Inc.
New Murphy Road
Wilmington, DE 19897
Telephone: 302-886-1000 or 800-323-8633
Review by Basic Manufacturer:
Comments solicited: October, 1994
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