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EXTOXNET primary files maintained and archived at Oregon State
Revised June 1996
Trade and Other Names:Trade
names include AC 217,300, Amdro, Combat, Maxforce, and Wipeout.
Hydramethylnon is a slightly toxic compound in EPA toxicity class
III. Products containing hydramethylnon must bear the Signal Word
CAUTION. It is a General Use Pesticide (GUP) .
Hydramethylnon is a trifluoromethyl aminohydrazone insecticide
used in baits to control fire ants, leafcutter ants, and
cockroaches in both indoor and outdoor applications. It is
available in a ready-to-use bait formulation. The data presented
here refer to the technical product unless otherwise stated.
Formulation: It is
available in a ready-to-use bait formulation.
- Acute toxicity: Hydramethylnon is
slightly toxic via ingestion, with reported oral LD50
valus of 1100 to 1300 mg/kg in rats . It is also
slightly toxic by skin exposure, with a dermal LD50 in
rabbits of greater than 5000 mg/kg . The reported
4-hour inhalation LC50 for hydramethylnon is greater than
5 mg/L, indicating slight toxicity by this route as well
. It is not reported to cause skin sensitization in
guinea pigs nor skin irritation in rabbits . It may,
however, be an eye irritant in rabbits . Acute
exposure in humans may result in irritation of the eyes
and mucous membranes of the respiratory tract.
- Chronic toxicity: In a 26-week study in
male and female dogs, doses of up to 3.0 mg/kg/day
resulted in increased liver wieghts and increased
liver:body weight ratios. No other effects were
observable in either the structure of tissues examined,
the chemistry and consistency of the blood, or the
chemistry of other bodily fluids . A 2-year study in
rats showed decreased food consumption and organ weight
changes at 5.0 mg/kg/day, but not at 2.5. mg/kg/day .
Similar effects were seen in rats over 90 days at the
same doses . In dogs, 6 mg/kg/day caused decreased
food consumption and body weight gain over a 90-day
period . In an 18-month cancer assay, hydramethylnon
at about 3.8 mg/kg/day was associated with amyloidosis, a
syndrome in which abnormal protein deposition in the
kidney fitration unit (glomerulus) results in damage
- Reproductive effects: Doses of 6
mg/kg/day caused testicular atrophy in dogs in a 90-day
feeding study . In rats, this effect was also
observed at doses of approximately 5 mg/kg/day over the
same time frame . Testicular lesions were seen in
mice at doses of approximately 3.8 mg/kg/day over 18
months. Male infertility, probably attributable to
testicular effects, was seen in a three-generation rat
study at 5 mg/kg/day . The available data suggest
that reproductive effects are unlikely in humans at
expected exposure levels.
- Teratogenic effects: Maternal body
weight gain was reduced in rats at 10 mg/kg/day, but not
at 3 mg/kg/day in a teratology study . In the same
study, maternal doses of 30 mg/kg/day were required to
produce decreased fetal weights . In another study of
potential birth defects in rabbits, reduced fetal weight
gain was also noted, but at a dose of 10 mg/kg/day .
It was not clear whether the decrements in fetal weight
were severe enough to result in reduced survival rate.
The available data suggest that teratogenic effects are
unlikely in humans at expected exposure levels.
- Mutagenic effects: Not Available
- Carcinogenic effects: In an 18-month
tumor assay in mice, no increases in tumor rates were
reported at doses of up to 3.8 mg/kg/day . The data
regarding carcinogenic effects are insufficient, but
suggest that hydramethylnon is not carcinogenic.
- Organ toxicity: Chronic studies in
several animals have shown the testis as a target organ.
- Fate in humans and animals: In rats,
following oral administration, hydramethylnon was rapidly
eliminated in the feces and urine . No residues were
detectable in the milk or tissues of goats at a dietary
dose of 0.2 ppm in the daily diet for 8 days . No
residues were found in the milk or tissues of cows at a
dietary dose of 0.05 ppm for 21 consecutive days .
- Effects on birds: The oral LD50 for
hydramethylnon in mallard ducks is greater than 2510
mg/kg, and in bobwhite quail is 1828 mg/kg, indicating
that the compound is practically nontoxic to these
- Effects on aquatic organisms:
Hydramethylnon is highly to very highly toxic to fish in
laboratory studies . The reported 96-hour LC50 values
for hydramethylnon are 160 ug/L in rainbow trout, 100
ug/L in channel catfish, and 1700 ug/L in bluegill
sunfish [1,8]. The reported 72-hour LC50 of
hydramethylnon in carp is 340 ug/L . The 48-hour LC50
for the compound in waterfleas (Daphnia) is 1.14 mg/L
. Hydramethylnon accumulated in bluegill sunfish at
1300 times its concentration in surrounding waters,
indicating low to moderate capacity to bioaccumulate .
Due to its very low water solubility, it is not likely to
be found in surface waters.
- Effects on other organisms:
Hydramethylnon is nontoxic to honey bees .
- Breakdown in soil and groundwater:
Hydramethylnon is of low persistence in the soil
environment; soil half-lives of 7 to 28 days have been
reported [11,154]. A representative value is estimated to
be 10 days [11,154]. However, a soil half-life of 18
hours has been reported, with breakdown probably due to
decomposition by light and the rapid foraging of ants
[11,154]. Because hydramethylnon is only slightly soluble
in water and is very strongly sorbed by soil organic
matter and clay particles, it is not appreciably mobile
in most soils [11,154]. These properties, along with its
low persistence, make it unlikely to contaminate
groundwater [11,154]. When Amdro, a granular bait
formulation, was applied to an aged soil column under
laboratory conditions, 72% of the applied material
remained in the treated soil after 45 days . Less than
0.2% was recovered in leachate. This evidence supports
the conclusion that neither Amdro nor its metabolites
- Breakdown in water: The reported
hydrolysis half-life for hydramethylnon is 10 to 11 days
over a pH range of 7 to 8.9, and 24 to 33 days at a pH of
- Breakdown in vegetation: Over a 90-day
rotation interval, hydramethylnon did not accumulate in
crop plants . In another study, residues in grass 4
months after treatment were less than 0.01 ppm.
Negligible residues were found in radishes, barley, and
French beans planted 3 months after treatment of the soil
- Appearance: Hydramethylnon is an
odorless, yellow to orange crystalline solid .
- Chemical Name:
- CAS Number: 67485-29-4
- Molecular Weight: 494.50
- Water Solubility: 0.005-0.007 mg/L @ 25
- Solubility in Other Solvents: v.s. in
acetone, chlorobenzene, methanol, ethanol, and xylene 
- Melting Point: 185-190 C 
- Vapor Pressure: 0.0027 mPa @ 25 C 
- Partition Coefficient: 2.3139 
- Adsorption Coefficient: 730,000 
- ADI: Not Available
- MCL: Not Available
- RfD: Not Available
- PEL: Not Available
- HA: Not Available
- TLV: Not Available
One Cyanamid Plaza
Wayne, NJ 07470-8426
- Phone: 201-831-2000
- Emergency: 201-835-3100
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