The information in this profile may be out-of-date. It was last revised
in 1996. EXTOXNET no longer updates this information, but it may be useful
as a reference or resource.
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E X T O X N E T
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
EXTOXNET primary files maintained and archived at Oregon State
Revised June 1996
Trade and Other Names:
Trade names include Aljaden, Alloxol S, BAS 9052H, Checkmate,
Expand, Fervinal, Grasidim, Nabu, NP-55, Poast, Tritex-Extra, and
Sethoxydim is a General Use Pesticide (GUP). It is in EPA
toxicity class III - slightly toxic. Products containing
sethoxydim bear the Signal Word CAUTION on the label.
Chemical Class: Not
Sethoxydim is a selective post-emergence herbicide used to
control annual and perennial grass weeds in broad-leaved
vegetable, fruit, field, and ornamental crops. It also has indoor
uses. It is available in emulsifiable concentrate formulations.
Formulation: It is
available in emulsifiable concentrate formulations.
- Acute toxicity: Sethoxydim is slightly
toxic by ingestion, and practically nontoxic by dermal
absorption . It causes skin and eye irritation.
Inhalation of dusts or vapors can cause irritation of the
throat and nose . Other symptoms of poisoning include
incoordination, sedation, tears, salivation, tremors,
blood in the urine, and diarrhea . Sethoxydim does
not cause allergic skin reactions . The oral LD50 for
sethoxydim in rats is 2600 to 3100 mg/kg [1,58]. The
dermal LD50 in rats is greater than 5000 mg/kg (1,58) and
the 4-hour inhalation LC50 for sethoxydim in rats is
greater than 6.3 mg/L .
- Chronic toxicity: Long-term contact with
sethoxydim can cause redness and swelling of the eyes or
skin . No adverse effects were observed in mice given
2, 6, or 18 mg/kg/day for 2 years [58,126]. In a 1-year
dog feeding study, doses above 8.86 mg/kg/day in males
and 9.41 mg/kg/day in females produced anemia [13,58].
- Reproductive effects: When pregnant
rabbits were fed 40, 160, or 480 mg/kg/day, decreased
litter size, low fetal weights, severe maternal weight
loss, increased fetal resorptions, spontaneous abortions,
and maternal deaths occurred at the 480 mg/kg level
. Based on this study, reproductive effects are
unlikely in humans at expected exposure levels.
- Teratogenic effects: No developmental
effects were observed in offspring of rats at maternal
dose levels of 40, 100, or 250 mg/kg/day . Increased
numbers of skeletal and visceral abnormalities occurred
in rabbits at doses of 480 mg/kg/day . These data
suggest that sethoxydim is unlikely to be teratogenic in
humans at expected exposure levels.
- Mutagenic effects: Several tests of the
mutagenicity of sethoxydim indicate that it is not
- Carcinogenic effects: No carcinogenic
effects were observed at any dose level when mice were
fed 6, 18, 54, or 162 mg/kg/day for 2 years [13,126].
This suggests that sethoxydim is not carcinogenic.
- Organ toxicity: Liver and bone marrow
effects and increased thyroid weight have been reported
in dogs .
- Fate in humans and animals: Single doses
of the compound fed to rats were nearly completely
eliminated (98.6%) through urine and feces within 48
- Effects on birds: Sethoxydim is
practically nontoxic to birds. The acute oral LD50 for
sethoxydim in mallard ducks is greater than 2510 mg/kg
, and in Japanese quail is greater than 5000 mg/kg
. Its dietary LC50 in mallards and bobwhite quail is
greater than 5620 ppm [58,127].
- Effects on aquatic organisms: Sethoxydim
is moderately to slightly toxic to aquatic species. A
3-hour LC50 of 1.5 mg/L is reported in Daphnia . In
fish, 96-hour LC50 valuees range from 1.6 mg/L in carp
, to 32 mg/L in rainbow trout, and 100 mg/L in
bluegill sunfish .
- Effects on other organisms: Sethoxydim
has low toxicity to wildlife . It is nontoxic to bees
- Breakdown in soil and groundwater:
Sethoxydim is of low soil persistence. Reported field
half-lives are 5 to 25 days [58,11]. It has a weak
tendency to adsorb to soil particles . Laboratory
leaching tests have suggested that sethoxydim could leach
in soil. However, in field tests, sethoxydim did not
leach below the top 4 inches of soil, and it did not
persist . On soil, photodegradation of sethoxydim
takes less than 4 hours . The product Poast
photodegrades on soil surfaces with a half-life of
approximately 3.7 hours . Disappearance of
sethoxydim is primarily due to action by soil microbes.
- Breakdown in water: In water,
photodegradation of sethoxydim takes less than 1 hour
. The product Poast is fairly stable to the chemical
action of water (hydrolysis), with a half-life of about
40 days in a neutral solution at 25 C .
- Breakdown in vegetation: Sethoxydim is
absorbed rapidly by roots and foliage, and moves both
upward and downward in plants from the point of
absorption . Sethoxydim is rapidly detoxified in most
tolerant plants . The product Poast accumulates in
the tissues of crops planted in fields after harvest of
treated crops. Measured residues were all below 0.066 ppm
- Appearance: Sethoxydim is an
amber-colored, oily, odorless liquid .
- Chemical Name: (+/-) 2 [1(ethoxyimino)
- CAS Number: 74051-80-2
- Molecular Weight: 327.50
- Water Solubility: 4700 mg/L @ pH 7 and
20 C 
- Solubility in Other Solvents: v.s. in
methanol, hexane, and acetone 
- Melting Point: Not Available
- Vapor Pressure: <0.1 mPa @ 20 C 
- Partition Coefficient: 1.6542 @ pH 7
- Adsorption Coefficient: 100 (estimated)
- ADI: Not Available
- MCL: Not Available
- RfD: 0.09 mg/kg/day 
- PEL: Not Available
- HA: Not Available
- TLV: Not Available
Agricultural Products Group
P.O. Box 13528
Research Triangle Park, NC 27709-3528
- Phone: 800--669-2273
- Emergency: 800-832-4357
References for the information in this PIP can be found in
Reference List Number 10
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