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The information in this profile may be out-of-date.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.

Please visit the National Pesticide Information Center (NPIC) to find updated pesticide fact sheets. If you don't find a fact sheet related to your question, feel free to call 1-800-858-7378. NPIC is open five days a week from 8:00am to 12:00pm Pacific Time.

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E X T O X N E T

Extension Toxicology Network

Pesticide Information Profiles

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 Assessment Program.

EXTOXNET primary files maintained and archived at Oregon State University

Revised June 1996

Hydramethylnon

Trade and Other Names:Trade names include AC 217,300, Amdro, Combat, Maxforce, and Wipeout.

Regulatory Status: 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) [1].

Chemical Class: trifluoromethyl aminohydrazone

Introduction: 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.

Toxicological Effects:

• Acute toxicity: Hydramethylnon is slightly toxic via ingestion, with reported oral LD50 valus of 1100 to 1300 mg/kg in rats [1]. It is also slightly toxic by skin exposure, with a dermal LD50 in rabbits of greater than 5000 mg/kg [1]. The reported 4-hour inhalation LC50 for hydramethylnon is greater than 5 mg/L, indicating slight toxicity by this route as well [1]. It is not reported to cause skin sensitization in guinea pigs nor skin irritation in rabbits [8]. It may, however, be an eye irritant in rabbits [1]. 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 [13]. 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 [13]. Similar effects were seen in rats over 90 days at the same doses [13]. In dogs, 6 mg/kg/day caused decreased food consumption and body weight gain over a 90-day period [13]. 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 [13].
• Reproductive effects: Doses of 6 mg/kg/day caused testicular atrophy in dogs in a 90-day feeding study [13]. In rats, this effect was also observed at doses of approximately 5 mg/kg/day over the same time frame [13]. 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 [13]. 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 [13]. In the same study, maternal doses of 30 mg/kg/day were required to produce decreased fetal weights [13]. 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 [13]. 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 [13]. 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 [8]. 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 [8]. No residues were found in the milk or tissues of cows at a dietary dose of 0.05 ppm for 21 consecutive days [1].

Ecological Effects:

• 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 species [8].
• Effects on aquatic organisms: Hydramethylnon is highly to very highly toxic to fish in laboratory studies [8]. 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 [1]. The 48-hour LC50 for the compound in waterfleas (Daphnia) is 1.14 mg/L [8]. Hydramethylnon accumulated in bluegill sunfish at 1300 times its concentration in surrounding waters, indicating low to moderate capacity to bioaccumulate [8]. 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 [8].

Environmental Fate:

• 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 [8]. Less than 0.2% was recovered in leachate. This evidence supports the conclusion that neither Amdro nor its metabolites leach [8].
• 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 4.9 [8].
• Breakdown in vegetation: Over a 90-day rotation interval, hydramethylnon did not accumulate in crop plants [154]. 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 [8].

Physical Properties:

• Appearance: Hydramethylnon is an odorless, yellow to orange crystalline solid [1].
• Chemical Name: 5,5-dimethylperhydropyrimidin-2-one 4-trifluoromethyl-alpha-(4-trifluoromethylstyryl)-cinnamylidenehydrazone [1]
• CAS Number: 67485-29-4
• Molecular Weight: 494.50
• Water Solubility: 0.005-0.007 mg/L @ 25 C [1]
• Solubility in Other Solvents: v.s. in acetone, chlorobenzene, methanol, ethanol, and xylene [1]
• Melting Point: 185-190 C [1]
• Vapor Pressure: 0.0027 mPa @ 25 C [1]
• Partition Coefficient: 2.3139 [1]
• Adsorption Coefficient: 730,000 [11]

Exposure Guidelines:

• ADI: Not Available
• MCL: Not Available
• RfD: Not Available
• PEL: Not Available
• HA: Not Available
• TLV: Not Available

Basic Manufacturer:

American Cyanamid
One Cyanamid Plaza
Wayne, NJ 07470-8426

• Phone: 201-831-2000
• Emergency: 201-835-3100
  

References:

References for the information in this PIP can be found in Reference List Number 10

DISCLAIMER: The 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 product labeling.