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in 1996. EXTOXNET no longer updates this information, but it may be useful
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E X T O X N E T
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and the Institute for Environmental Toxicology, Michigan State
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EXTOXNET primary files maintained and archived at Oregon State
Revised June 1996
Trade and Other Names:
Trade names include Alirox, Eptam, Eradicane, Eradicane Extra,
Genep, Genep Plus, and Shortstop.
EPTC is a slightly toxic compound in EPA toxicity class III. It
is a General Use Pesticide (GUP); labels for products containing
EPTC must bear the Signal Word CAUTION.
EPTC is a selective thiocarbamate herbicide used for control of
annual grassy weeds, perennial weeds, and some broadleaf weeds in
beans, forage legumes, potatoes, corn, and sweet potatoes. It is
usually applied preemergence, that is before weed seeds
germinate, and is usually incorporated into the soil immediately
after application either mechanically or by overhead irrigation.
EPTC is available as emulsifiable concentrates and granular
Formulation: EPTC is
available as emulsifiable concentrates and granular formulations.
- Acute toxicity: EPTC is slightly toxic
via ingestion, with reported oral LD50 values of 1632
mg/kg in rats, 3160 mg/kg in mice, 112 mg/kg in cats, and
2460 mg/kg in rabbits [4,7]. It is slightly toxic via the
dermal route as well, with reported dermal LD50 values of
5000 mg/kg in rabbits and 3200 mg/kg in rats . The
reported 1-hour inhalation LC50 in rats of 31.56 mg/L
indicates slight toxicity by this route . It is a mild
to moderate skin irritant in rabbits, a weak skin
sensitizer in guinea pigs, and a mild eye irritant in
rabbits . EPTC is a cholinesterase inhibitor. Early
symptoms of cholinesterase inhibition are blurred vision,
fatigue, headache, vertigo, nausea, pupil contraction,
abdominal cramps, and diarrhea. Severe inhibition of
cholinesterase may cause excessive sweating, tearing,
slowed heartbeat, giddiness, slurred speech, confusion,
excessive fluid in the lungs, convulsions, and coma.
Workers subjected to inhalation exposure to EPTC
experienced headaches, nausea, general malaise, and
impaired working capacity. Animals poisoned in
experimental tests displayed excitement, salivation,
tearing, spasmodic winking, and depression (28,29).
- Chronic toxicity: In a 16-week study of
dogs fed 45 mg/kg/day, effects of brain cholinesterase
inhibition and gastric mucosal changes were reported
. In a 54-week feeding study of EPTC no effects were
observed at 20 mg/kg/day . In a two-generation study
with rats fed 10 or 40 mg/kg/day, technical EPTC caused
degeneration of tissues of the spinal chord, nerves,
muscle, and heart tissue. No evidence of these effects
was seen in a survey of workers who produced and
formulated technical EPTC .
- Reproductive effects: In a study where
oral doses of 30, 100 or 300 mg/kg/day were administered
on days 6 to 15 of pregnancy, maternal mortality and
decreased weight gain and food consumption occurred at
the highest dose. Decreased fetal body weight and
increased loss of fetuses occurred at 100 and 300
mg/kg/day . It is not likely that EPTC will cause
reproductive effects in humans under normal
- Teratogenic effects: No effects were
observed in a teratogenic study in which rats were given
300 mg/kg/day [7,27]. The available evidence suggests
that EPTC is not teratogenic.
- Mutagenic effects: EPTC was not
mutagenic when tested in a series of assays with
microbial and human cell culture lines [7,29].
- Carcinogenic effects: In a 2-year
feeding and oncogenicity study of EPTC in mice no excess
tumors were seen at doses of up to 20 mg/kg/day . The
available evidence suggests that EPTC is not
- Organ toxicity: In lifetime studies with
animals, the target organs of technical EPTC toxicity
were nerves, muscle, and heart tissue .
- Fate in humans and animals: In rats, low
oral amounts of EPTC (approximately 0.6 mg) were mainly
eliminated via expired air, and much smaller amounts were
eliminated via the urine and feces. When the amount was
increased to 100 mg, the relative proportion excreted via
urine and feces was increased .
- Effects on birds: EPTC is slightly toxic
to relatively nontoxic to birds. The oral LC50 for
technical EPTC in bobwhite quail is 20,000 ppm for a
7-day feed treatment .
- Effects on aquatic organisms: EPTC is slightly toxic to
fish and aquatic organisms. The reported 96-hour LC50
values for EPTC are 19 mg/L in rainbow trout, 27 mg/L in
bluegill sunfish, 17 mg/L in mosquito fish, 17 mg/L in
cuttthroat trout, and 16 mg/L in lake trout [3,7,16]. The
24-hour LC50 in the blue crab is greater than 20 mg/L
. Bioconcentration values for fish range from 37 to
190 times the ambient water concentration indicating that
the compound will not significantly accumulate in these
- Effects on other organisms: EPTC is
practically nontoxic to bees, with a reported LD50 of
0.011 mg per bee .
- Breakdown in soil and groundwater: EPTC
is of low persistence in the soil environment, with
reported field half-lives of 6 to 32 days; a
representative field half-life for most soil regimes is 6
days . It is not strongly bound to soils, especially
those lower in organic matter and clay content [7,20].
Microbial breakdown and volatilization are the main
mechanisms by which EPTC is lost from soils . Due to
its short half-life, it is not a threat to groundwater.
- Breakdown in water: There is little
chance that it will enter surface waters, due to its
- Breakdown in vegetation: EPTC is readily
absorbed by the roots of plants and translocated upward
to the leaves and stems. EPTC is rapidly metabolized by
plants to carbon dioxide and naturally occurring plant
- Appearance: EPTC is a colorless to pale
yellow liquid with an aromatic odor .
- Chemical Name: s-ethyl
- CAS Number: 759-94-4
- Molecular Weight: 189.32
- Water Solubility: 375 mg/L @ 25 C 
- Solubility in Other Solvents: v.s. in
acetone, ethyl alcohol, kerosene, methyl isobutyl ketone,
and xylene 
- Melting Point: Not Available
- Vapor Pressure: 4700 mPa @ 25 C 
- Partition Coefficient: 3.2041 
- Adsorption Coefficient: 200 
- ADI: Not Available
- MCL: Not Available
- RfD: Not Available
- PEL: Not Available
- HA: Not Available
- TLV: Not Available
Zeneca Ag Products
1800 Concord Pike
Wilmington DE 19897
- Phone: 800-759-4500
- Emergency: 800-759-2500
References for the information in this PIP can be found in
Reference List Number 4
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