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EXTOXNET primary files maintained and archived at Oregon State
Revised June 1996
Trade and Other Names:
Trade names include Blade, DPX 1410, Oxamil, Oxamimidic Acid,
Pratt, Thioxamil, and Vydate.
Oxamyl is a highly toxic compound in EPA toxicity class I. The
U.S. Environmental Protection Agency (EPA) has classified most
products containing oxamyl as Restricted Use Pesticides (RUPs)
due to oxamyl's acute toxicity to humans and its toxicity to
birds and mammals. Restricted Use Pesticides may be purchased and
used only by certified applicators. Granular formulations of
oxamyl are banned in the United States. Labels on containers of
oxamyl and/or its formulated products must bear the Signal Words
DANGER - POISON.
Oxamyl is a carbamate insecticide/acaricide/nematicide that
controls a broad spectrum of insects, mites, ticks, and
roundworms. It may work both through systemic distribution in the
target pest and on contact. Oxamyl is used on field crops,
vegetables, fruits, and ornamental plants and may be applied
directly onto plants or the soil surface. It is available in both
liquid and granular form, but as is stated above, the granular
form is banned in the U.S.
Formulation: It is
available in both liquid and granular form, but as is stated
above, the granular form is banned in the U.S.
- Acute toxicity: Oxamyl is highly toxic
via the oral route, with a reported oral LD50 of 5.4
mg/kg in rats . Exposure to oxamyl will cause similar
effects to the other carbamate compounds, and as with
other carbamates the cholinesterase-inhibiting effects
are short-term and reversible . These effects include
headache, nausea, sweating, tearing, tremors, and blurred
vision. It is slightly toxic via the dermal route, with a
reported dermal LD50 for technical oxamyl of 2960 mg/kg
in rabbits . Skin and eye exposure may cause
poisoning, although absorption through the skin and eye
is slower than through the gastrointestinal tract .
Exposure of rabbit's eyes to technical oxamyl caused mild
irritation . Oxamyl is highly toxic via the inhalation
route as well with a reported 4-hour LC50 of 0.12 to 0.17
mg/L in rats .
- Chronic toxicity: Prolonged or repeated
exposure to oxamyl may cause symptoms similar to those
caused by acute exposure. In a 2-year mouse feeding
study, no effects were observed at a dose of 1.25
mg/kg/day, although at the very high doses of 2.5 and
3.75 mg/kg/day there was decreased body weight and
changed nutritional performance . Liver impairment
was suggested by a slight biochemical change seen in dogs
that were fed 3.75 mg/kg/day as a part of a 2-year
feeding study . Male rats fed the very high dose of
7.5 mg/kg/day oxamyl for 2 years had decreased organ
weight of the heart, testes, and adrenals. In females,
there was an increase in the relative weights of the
brain, heart, lungs, and adrenals at these doses .
- Reproductive effects: When pregnant rats
were fed oxamyl, no effects were observed (relative to
unexposed animals) on the number of implantation sites,
resorptions, and live fetuses in rats fed doses of 2.5,
5, 7.5, or 15 mg/kg/day on days 6 through 15 of
pregnancy. There were, however, dose-related decreases in
maternal body weights and in food consumption rates .
Litter size, viability, lactation and body weights of
offspring were decreased in a three-generation (two
litters per generation) reproduction study in rats fed
very high doses, approximately 5 and 7.5 mg/kg/day
technical oxamyl . Based on these studies, oxamyl is
unlikely to cause reproductive effects in humans at
expected exposure levels.
- Teratogenic effects: No teratogenic
effects were observed in the offspring of rabbits fed 2
and 4 mg/kg/day during days 6 to 19 of gestation .
Oxamyl was not teratogenic or embryotoxic in the
offspring of pregnant rats fed up to 15 mg/kg/day of the
insecticide [3,42]. No teratogenic effects were observed
in rabbits given oxamyl levels at doses of approximately
4 mg/kg/day in the diet . Thus, it appears that oxamyl
does not cause teratogenic effects.
- Mutagenic effects: Oxamyl was not
mutagenic in several test systems [5,42].
- Carcinogenic effects: In a study of mice
fed up to 9 mg/kg/day, no carcinogenic effects were seen
. In addition, no evidence of carcinogenic potential
was seen following long-term dietary exposure of rats
. This indicates that oxamyl is not carcinogenic.
- Organ toxicity: Effects noted in animal
studies include changes in liver function, and changes in
organ weights of the brain, heart, lungs, testes, and
- Fate in humans and animals: When oxamyl
was administered to rats, most of the dose was rapidly
eliminated in the urine and feces as breakdown
by-products, or metabolites . Carbamates generally are
excreted rapidly and do not accumulate in mammalian
- Effects on birds: Oxamyl is very highly
toxic to birds . The acute oral LD50 for oxamyl in
quail is 4.18 mg/kg . Hens given single oral doses of
oxamyl at 20 to 40 mg/kg of body weight followed by
intramuscular injections of 0.5 mg of atropine, an
antidote, exhibited early symptoms of cholinesterase
inhibition with full recovery after 12 hours. No signs of
delayed neurotoxicity were observed in these same hens
. The oral LD50 for oxamyl is 2.6 mg/kg in mallard
ducks and 9.4 mg/kg in bobwhite quail .
- Effects on aquatic organisms: Oxamyl is
moderately to slightly toxic to fish . The reported
96-hour LC50 values for technical oxamyl are 5.6 mg/L in
bluegill sunfish, 27.5 mg/L in goldfish, 4.2 mg/L in
rainbow trout and 17.5 mg/L in channel catfish .
Concentrations of 0.5 to 5.0 mg/L may have an effect on
Daphnia magna, an aquatic invertebrate .
- Effects on other organisms: Oxamyl is
highly toxic to bees .
- Breakdown in soil and groundwater:
Oxamyl is of low persistence in soil with reported field
half-lives of 4 to 20 days . Loss is due to
decomposition by aerobic and anaerobic bacteria (44).
Oxamyl is hydrolyzed rapidly in neutral and alkaline
soils and more slowly in acid soils . It does not
readily bind, or "adsorb," to soil or sediments
and it has been shown to leach in soil [13,42]. Its
adsorption is strongest in soils of high organic matter,
and on sandy loam is fairly weak. An increase in
temperature causes a decrease in adsorption . Since
oxamyl degrades relatively quickly in the presence of
bacteria, it is more likely to be found in groundwater
than in surface water. It has been found in very small
amounts in the states of New York (1 to 60 ug/L) and
Rhode Island (1 ug/L) . Wherever conditions favor
very rapid movement of leachate, oxamyl may reach the
- Breakdown in water: In a river water
study, oxamyl had a half-life of 1 to 2 days .
- Breakdown in vegetation: Oxamyl has a
residual period in plants of approximately 1 to 2 weeks.
It is considered non-toxic to plants . Plants take
oxamyl up through both leaves and roots; it is
translocated in treated plants . Oxamyl is
metabolized rapidly by plants .
- Appearance: Oxamyl is a colorless or
white crystalline solid with a garlic-like odor.
- Chemical Name:
- CAS Number: 23135-22-0
- Molecular Weight: 219.36
- Water Solubility: 280 g/L @ 25 C 
- Solubility in Other Solvents: v.s. in
acetone, ethanol, 2-propanol, and methanol; s. in toluene
- Melting Point: 100-102 C , at which
point it changes to a different crystalline structure
that melts at 108-110 C 
- Vapor Pressure: 31 mPa @ 25 C 
- Partition Coefficient: Not Available
- Adsorption Coefficient: 25 
- ADI: 0.03 mg/kg/day 
- MCL: 0.2 mg/L 
- RfD: 0.025 mg/kg/day 
- PEL: Not Available
- HA: Not Available
- TLV: Not Available
DuPont Agricultural Products
Walker's Mill, Barley Mill Plaza
P.O. Box 80038
Wilmington, DE 19880-0038
- Phone: 800-441-7515
- Emergency: 800-441-3637
References for the information in this PIP can be found in
Reference List Number 3
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