FLUORIDE ACTION NETWORK PESTICIDE PROJECT
Return to FAN's Pesticide Homepage
Return to Hydramethylnon Index Page
Hydramethylnon. TOXNET profile from Hazardous Substances Data Bank.
HYDRAMETHYLNON
CASRN: 67485-29-4
For other data, click on the Table of Contents
Human Health Effects:
Probable Routes of Human Exposure:
Occupational exposure to hydramethylnon
may occur through inhalation of dust particles and dermal contact with this
compound at workplaces where hydramethylnon
is produced or used. The general population may be exposed to hydramethylnon
via ingestion and dermal contact with food and other products containing hydramethylnon.
(SRC)
Emergency Medical Treatment:
Animal Toxicity Studies:
Non-Human Toxicity Excerpts:
Non-teratogenic and non-embryotoxic in rats and rabbits. Non-mutagenic.
Not a skin irritant to rabbits or guinea pigs, reversible irritant to eyes
of rabbits. No skin sensitization in guinea pigs.
Non-Human Toxicity Values:
LD50 Rat male oral 1,131 mg/kg, female rat 1,300 mg/kg
LD50 Rabbit percutaneous >5,000 mg/kg
NOEL Rat 75 mg/kg diet /28-day trial/
NOEL Rat 50 mg/kg diet /90-day trial/
NOEL Rat 50 mg/kg diet /2-yr trial/
NOEL Mouse 25 mg/kg diet /18-month trial/
NOEL Beagle 3.0 mg/kg daily /90-day trial/
NOEL Beagle 3.0 mg/kg daily /6-month trial/
Ecotoxicity Values:
LD50 Mallard duck oral >2,510 mg/kg
LD50 Bobwhite quail oral 1,828 mg/kg
LC50 Bluegill sunfish 1.70 mg/L/96 hr /conditions of bioassay not specified/
LC50 Rainbow trout 0.16 mg/L/96 hr /conditions of bioassay not specified/
LC50 Channel catfish 0.10 mg/L/96 hr /conditions of bioassay not specified/
LC50 Carp 0.34 mg/L/72 hr /conditions of bioassay not specified/
EC50 Daphnia 1.14 mg/L/48 hr /conditions of bioassay not specified/
Metabolism/Pharmacokinetics:
Absorption, Distribution & Excretion:
In rats, following oral admin, rapidly eliminated in the feces and urine.
No residues were detectable in the milk or tissues of goats (0.2 mg/kg in
the daily diet for 8 days). No residues were found in the milk or tissues of
cows (0.05 mg/kg for 21 consecutive days).
Pharmacology:
Environmental Fate & Exposure:
Environmental Fate/Exposure Summary:
Hydramethylnon's (Amdro)
production and use as a slow-acting toxicant used successfully in bait for the
fire ant, other ants, and cockroaches will result in its release to the environment.
If released into the atmosphere, hydramethylnon
is expected to exist predominantly in the particulate phase in the ambient atmosphere,
based on an experimental vapor pressure of 2.0X10-8 mm Hg at 25 deg C. Vapor
phase hydramethylnon is degraded in
the atmosphere by reaction with photochemically-produced hydroxyl radicals with
a half-life of about 2.7 hours. An estimated Koc value of 430 suggests that
hydramethylnon will have moderate mobility
in soil. The average Rf value for hydramethylnon,
determined using TLC, was reported to be 0.64, again suggesting that hydramethylnon
is expected to have moderate mobility in soil. The half-life of hydramethylnon
in sandy loam was determined to range from approximately 7 to 28 days. Volatilization
from moist soil may be an important fate process based upon an estimated Henry's
Law constant of 2.2X10-6 atm-cu m/mole. Volatilization from dry soil surfaces
should not be important given the vapor pressure of this compound. In water,
hydramethylnon is expected to adsorb
very little to sediment or particulate matter based on its Koc value. This compound
may be expected to volatilize from water surfaces given its estimated Henry's
Law constant. Estimated volatilization half-lives for a model river and model
lake are 37 days and 278 days, respectively. Photolysis has been determined
to be an important fate process for hydramethylnon.
Hydramethylnon is rapidly degraded in
sunlight by photolysis, with a half-life of approximately 1 hour; formulated
bait decomposes rapidly in daylight. Sunlight irradiation of hydramethylnon
in aqueous media at various pH values resulted in 80 to 94 percent transformation
within 10 hours. Hydramethylnon recoveries
were 11.28, 9.43 and 6.32 percent with half-lives of 3.24, 3.0, and 2.58 hours
at pH 4.8, 6.5 and 8.0, respectively. Two major photoproducts of hydramethylnon
after 10 hours of irradiation isolated as pure crystalline substances were 1,5-bis(alpha,
alpha, alpha-trifluoro-p-tolyl)-1,4-pentadien-3-one and N,N'-azo-(5,5-dimethylperhydropyrimidin-2-one
hydrazone. Bioconcentration in aquatic organisms should be moderate based upon
an estimated BCF value of 36. Given the commercial uses of hydramethylnon,
human exposure appears to be likely from occupational situations through dermal
routes. The general population may be exposed to hydramethylnon
via ingestion and dermal contact with food and other products containing hydramethylnon.
(SRC)
Probable Routes of Human Exposure:
Occupational exposure to hydramethylnon
may occur through inhalation of dust particles and dermal contact with this
compound at workplaces where hydramethylnon
is produced or used. The general population may be exposed to hydramethylnon
via ingestion and dermal contact with food and other products containing hydramethylnon.
(SRC)
Artificial Pollution Sources:
Hydramethylnon's production and use
as a slow-acting toxicant used successfully in bait for the fire ant, other
ants, and cockroaches(1) will result in its release to the environment(SRC).
Environmental Fate:
TERRESTRIAL FATE: Based on a recommended classification scheme(1), an estimated
Koc value of 430(SRC), determined from an experimental log Kow(2,SRC) and a
recommended regression-derived equation(3), indicates that hydramethylnon
is expected to have moderate mobility in soil(SRC). Volatilization of hydramethylnon
from moist soil surfaces may be important(SRC) given an estimated Henry's Law
constant of 2.2X10-6 atm-cu m/mole(SRC), estimated from the experimental values
for water solubility(4) and vapor pressure(2). Hydramethylnon
is not expected to volatilize from dry soil surfaces based on an experimental
vapor pressure of 2.0X10-8 mm Hg(SRC). The half-life of hydramethylnon
in sandy loam was determined to range from approximately 7 to 28 days(2). The
average Rf value for hydramethylnon,
determined using soil TLC, was reported to be 0.64(5). According to a classification
scheme(6), this Rf value suggests that hydramethylnon
is expected to have moderate mobility in soil(SRC).
AQUATIC FATE: Based on a recommended classification scheme(1), an estimated
Koc value of 430(SRC), determined from an experimental log Kow(2,SRC) and a
recommended regression-derived equation(3), indicates that hydramethylnon
is expected to adsorb very little to suspended solids and sediment in water(SRC).
Hydramethylnon may volatilize from water
surfaces(3,SRC) based on an estimated Henry's Law constant of 2.2X10-6 atm-cu
m/mole(SRC), estimated from the experimental values for water solubility(4)
and vapor pressure(2). Estimated volatilization half-lives for a model river
and model lake are 37 days and 278 days, respectively(3,SRC). According to a
classification scheme(5), an estimated BCF of 36(3,SRC), from an experimental
log Kow(2,SRC), suggests that bioconcentration in aquatic organisms is moderate
high(SRC). Sunlight irradiation of hydramethylnon
in aqueous media at various pH values resulted in 80 to 94 percent transformation
within 10 hours. Hydramethylnon recoveries
were 11.28, 9.43 and 6.32 percent with half-lives of 3.24, 3.0, and 2.58 hours
at pH 4.8, 6.5 and 8.0, respectively(6). After 10 hours of irradiation, eight
photoproducts were formed and two were isolated as pure crystalline substances:
1,5-bis(alpha, alpha, alpha-trifluoro-p-tolyl)-1,4-pentadien-3-one and N,N'-azo-(5,5-dimethylperhydropyrimidin-2-one
hydrazone(6).
ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile
organic compounds in the atmosphere(1), hydramethylnon,
which has an experimental vapor pressure of 2.0X10-8 mm Hg at 25 deg C(3,SRC),
is expected to exist predominantly in the particulate phase in the ambient atmosphere.
Any vapor-phase hydramethylnon is degraded
in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC);
the half-life for this reaction in air is estimated to be about 2.7 hours(2,SRC).
Particulate-phase hydramethylnon may
be physically removed from the air by wet and dry deposition(SRC). Hydramethylnon
is rapidly degraded in sunlight by photolysis, with a half-life of approximately
1 hour; formulated bait decomposes rapidly in daylight(3). Sunlight irradiation
of hydramethylnon in aqueous media at
various pH values resulted in 80 to 94 percent transformation within 10 hours.
Hydramethylnon recoveries were 11.28,
9.43 and 6.32 percent with half-lives of 3.24, 3.0, and 2.58 hours at pH 4.8,
6.5 and 8.0, respectively(4). After 10 hours of irradiation, eight photoproducts
were formed and two were isolated as pure crystalline substances: 1,5-bis(alpha,
alpha, alpha-trifluoro-p-tolyl)-1,4-pentadien-3-one and N,N'-azo-(5,5-dimethylperhydropyrimidin-2-one
hydrazone(4).
Environmental Biodegradation:
The half-life of hydramethylnon in
sandy loam was determined to range from approximately 7 to 28 days(1).
Environmental Abiotic Degradation:
The rate constant for the vapor-phase reaction of hydramethylnon
with photochemically-produced hydroxyl radicals has been estimated as 1.43X10-11
cu cm/molecule-sec at 25 deg C(SRC) using a structure estimation method(1,SRC).
This corresponds to an atmospheric half-life of about 2.7 hours at an atmospheric
concentration of 5X10+5 hydroxyl radicals per cu cm(1,SRC). Hydramethylnon
is not expected to undergo hydrolysis in the environment due to the lack of
hydrolyzable functional groups(2). Hydramethylnon
is rapidly degraded in sunlight by photolysis, with a half-life of approximately
1 hour; formulated bait decomposes rapidly in daylight(3). Photodegradation
of C14-labeled hydramethylnon at benzylic
and pyrimidine-2 positions was carried out separately under borosilicate-filtered
xenon arc lamps (to simulate natural sunlight) at 27 deg C as a suspension in
distilled water. The half-life of hydramethylnon
was calculated to be 42 minutes. Photoproducts of benzylic C14-labeled hydramethylnon
include 1,5-bis(alpha, alpha, alpha-trifluoro-p-tolyl)-1,4-pentadien-3-one;
alpha, alpha, alpha-trifluoro-p-toluic acid; and p-(trifluoromethyl)cinnamic
acid. The photoproduct from both benzylic and pyrimidine-2 C14-labeled hydramethylnon
was determined to be 6,7,8,9-tetrahydro-7,7-dimethyl-3-(p-(trifluoromethyl)styryl)+-4H-pyrimido(2,1-c
)-as-triazin-4-one(4). Sunlight irradiation of hydramethylnon
in aqueous media at various pH values resulted in 80 to 94 percent transformation
within 10 hours. Hydramethylnon recoveries
were 11.28, 9.43 and 6.32 percent with half-lives of 3.24, 3.0, and 2.58 hours
at pH 4.8, 6.5 and 8.0, respectively(5). After 10 hours of irradiation, eight
photoproducts were formed and two were isolated as pure crystalline substances:
1,5-bis(alpha,alpha, alpha-trifluoro-p-tolyl)-1,4-pentadien-3-one and N,N'-azo-(5,5-dimethylperhydropyrimidin-2-one
hydrazone(5).
Environmental Bioconcentration:
An estimated BCF of 36 was calculated for hydramethylnon(SRC),
using an experimental log Kow of 2.31(1,SRC) and a recommended regression-derived
equation(2). According to a classification scheme(3), this BCF suggests that
bioconcentration in aquatic organisms is moderate(SRC).
Soil Adsorption/Mobility:
The Koc of hydramethylnon is estimated
as approximately 430(SRC), using a measured log Kow of 2.31(1) and a regression-derived
equation(2,SRC). According to a recommended classification scheme(3), this estimated
Koc value suggests that hydramethylnon
is expected to have moderate mobility in soil(SRC). The average Rf value for
hydramethylnon, determined using TLC,
was reported to be 0.64(4). According to a classification scheme(5), this Rf
value suggests that hydramethylnon is
expected to have moderate mobility in soil(SRC).
Volatilization from Water/Soil:
The Henry's Law constant for hydramethylnon
is estimated as 2.2X10-6 atm-cu m/mole(SRC) from its experimental values for
vapor pressure, 2.0X10-8 mm Hg(1), and water solubility, 0.006 mg/l(2). This
value indicates that hydramethylnon
may volatilize from water surfaces(3,SRC). Based on this Henry's Law constant,
the estimated volatilization half-life from a model river (1 m deep, flowing
1 m/sec, wind velocity of 3 m/sec) is estimated as approximately 37 days(3,SRC).
The estimated volatilization half-life from a model lake (1 m deep, flowing
0.05 m/sec, wind velocity of 0.5 m/sec) is estimated as approximately 278 days(3,SRC).
Hydramethylnon's Henry's Law constant(1,2,SRC)
indicates that volatilization from moist soil surfaces may occur(SRC). Hydramethylnon
is not expected to volatilize from dry soil surfaces(SRC) based on a measured
vapor pressure of 2.0X10-8 mm Hg(1).
Food Survey Values:
Negligible residues of hydramethylnon
were found in radishes, barley, and french beans planted three months after
treatment of the soil(1).
Plant Concentrations:
Residues of hydramethylnon in grass
four months after treatment were <0.01 ppm(1).
Animal Concentrations:
No residues of hydramethylnon were
detectable in the milk or tissues of goats after being exposed to 0.2 mg/kg
hydramethylnon in the daily diet for
8 days(1). No residues were found in the milk or tissues of cows after being
exposed to 0.05 mg/kg hydramethylnon
for 21 consecutive days(1).
Environmental Standards & Regulations:
Chemical/Physical Properties:
Molecular Formula:
C25-H24-F6-N4
Color/Form:
Yellow-tan, free-flowing granules
Crystals from isopropanol
Odor:
Characteristic of vegetable oil
Melting Point:
190 deg C
Octanol/Water Partition Coefficient:
log Kow = 2.31
Solubilities:
In acetone 360, ethanol 72, 1,2-dichloroethane 170, methanol 230, isopropanol
12, xylene 94, chlorobenzene 390 (all in g/l @ 20 deg C)
Water solubility = 0.006 mg/l @ 25 deg C
Vapor Pressure:
2.03X10-8 mm Hg @ 25 deg C
Chemical Safety & Handling:
Flash Point:
>220 deg F (SFCC)
Fire Fighting Procedures:
Water, foam, carbon dioxide, or dry chemical.
Preventive Measures:
Wash thoroughly after handling. Do not contaminate water, food, or feed by
storage or disposal.
Stability/Shelf Life:
When stored in original unopened container, stable in excess of 24 months
at 25 deg C, 12 months at 37 deg C, and 3 months at 45 deg C.
Undergoes photolysis in sunlight (DT50 circa 1 hour). DT50 in aqueous suspension
(25 deg C) 24-33 days at pH 4.9, 10-11 days at pH 7.03, and 11-12 days at pH
8.87.
Storage Conditions:
Store in a cool, dry, secure place and keep container tightly closed. Use
product within 3 months after opening for best results. /Amdro/
Cleanup Methods:
Sweep up any spill and place in a closed container for disposal. /Amdro/
Disposal Methods:
SRP: At the time of review, criteria for land treatment or burial (sanitary
landfill) disposal practices are subject to significant revision. Prior to implementing
land disposal of waste residue (including waste sludge), consult with environmental
regulatory agencies for guidance on acceptable disposal practices.
Occupational Exposure Standards:
Manufacturing/Use Information:
Major Uses:
Slow-acting insecticide for ants (big headed, fire,
harvester)
Slow activating stomach poison insecticide
A slow-acting toxicant used successfully in bait
for the fire ant, other ants, and cockroaches
Manufacturers:
American Cyanamid Co., One Campus Drive,
Parsippany, NJ 07054-4492 (201)683-2000
AgrEvo Environmental Health Ltd.(distributor), 95 Chestnut Ridge Rd., Montvale,
NJ 07645 (201)307-3281
American Cyanamid Company: Cyanamid Agricultural Products Division, P.O. Box
817, Route 168 and J.J. Spur, Hannibal, MO 63401
Methods of Manufacturing:
4-(Trifluormethylbenzaldehyde) + acetone + hydrazine + neopentyl glycol +
urea (carbonyl condensation/ imine formation/ condensation/ imine formation)
Formulations/Preparations:
J.B. Lovell, U.S. pat. 4,087,525 (1975 to Am. Cyanamid)
Laboratory Methods:
Special References:
Synonyms and Identifiers:
Formulations/Preparations:
J.B. Lovell, U.S. pat. 4,087,525 (1975 to Am. Cyanamid)
Administrative Information:
Hazardous Substances Databank Number: 6673
Last Revision Date: 20000929
Last Review Date: Reviewed by SRP on 9/18/1997
Update History:
Complete Update on 06/03/1998, 39 fields added/edited/deleted.