ethalfluralin (Curbit, Sonalan) Herbicide Profile 6/85
CHEMICAL FACT SHEET FOR:
FACT SHEET NUMBER: 58
DATE ISSUED: JUNE 30, 1985
1. DESCRIPTION OF CHEMICAL
- Generic Name: N-ethyl-N-(2-methyl-2-propenyl)-2,6-dinitro-4-
- Common Name: ethalfluralin
- Trade Names:
- EPA Shaughnessy Code: 113101
- Chemical Abstracts Service (CAS) Number: 55283-68-6
- Year of Initial Registration: 1983
- Pesticide Type: herbicide
- U.S. Producer: Elanco Products Company
2. USE PATTERNS AND FORMULATIONS
- Emulsifiable concentrate: Preplant incorporated (PPI) to dry peas,
dry beans, and soybeans.
- Surface applied, cucurbits direct seeded: cantaloupe, cucumber,
pumpkin, and watermelon.
3. SCIENCE FINDINGS
Ethalfluralin is a yellow crystalline solid with a faint amine odor.
It has a molecular weight of 333.3, a specific gravity of 1.32/ml,
a melting range of 57 to 59 degrees C, an n-octanol-to-water partition
coefficient of 5-11, a vapor pressure of 8.2 x 10(-5) mmHg at 25
degrees C, and is susceptible to decomposition by ultraviolet light.
Ethalfluralin is readily soluble in organic solvents; its solubility
in water is 0.3 ppm at 25 degrees C.
- Ethalfluralin is considered a skin sensitizer.
- EC formulation is irritating to the eyes and skin.
- EC formulation is toxic to fish.
- Toxicology studies on ethalfluralin are as follows:
- Oral LD50, rat: greater than 10 g/kg
- Oral LD50, mouse: greater than 10 g/kg
- Oral LD50, dog: greater than 200 mg/kg
- Oral LD50, cat: greater than 200 mg/kg
- Acute dermal LD50, rabbit: greater than 2 g/kg
- Primary eye irritation, rabbit: conjunctivitis, no corneal
- Acute inhalation LC50, rat: greater than 0.028 mg/l/hr.
- Toxicology studies on EC formulation are as follows:
- Oral LD50, rat: greater than 2 ml/kg
- Acute dermal LD50, rabbit: greater than 2 ml/kg
- Primary dermal irritation, rabbit: slight to moderate
- Primary eye irritation, rabbit: slight iritis and conjunctivitis;
corneal dulling reversible in 21 days
- Acute inhalation LC50, rat: greater than 74.4 l/l/hr.
- Ethalfluralin is oncogenic in the rat; mammary gland
fibroadenomas (benign) in females at mid (250) and high (750)
ppm dose levels. Using a one-hit model, the worst-case dietary
oncogenic risk is calculated to be 3.77 incidences in one million.
- Ethalfluralin is considered a teratogen in the rabbit; teratogenic
No-Observed-Effect-Level (NOEL) is 75 mg/kg.
Ethalfluralin binds readily to soil particles and is thus not prone to
leaching. It is volatile and readily photodegraded. Ethalfluralin
concentrations in water would be expected to decline rapidly with a
half-life of 1-2 days. Ethalfluralin residues may transport to
aquatic environments via soil erosion. Label warnings include: Do
not apply directly to any body of water or wetlands. Runoff or
erosion from treated areas may be hazardous to fish in neighboring
- Avian acute oral LD50: Bobwhite quail > 2,000 mg/kg
- Avian dietary LC50: Bobwhite quail > 5,000 ppm
- Avian dietary LC50: Mallard duck > 5,000 ppm
- Fish acute LC50: Bluegill, 0.032 ppm (highly toxic); rainbow trout,
0.037 ppm (highly toxic)
- Aquatic invertebrate acute LC50: <<Daphnia>>, 0.365 ppm (highly
- Mallard and bobwhite 1-generation reproduction: Supplementary
dietary levels up to 1,000 ppm did not affect reproduction.
Tolerance levels of 0.05 ppm established for parent compound
ethalfluralin in commodities: dry beans, dry peas, soybeans, and
cucurbit vegetable group. Real residues of ethalfluralin detectable
in forage items; thus label restriction, Do not graze or forage crop
grown in treated soil or cut for hay or silage.
4. SUMMARY OF REGULATORY POSITION AND RATIONALE
Ethalfluralin is regulated as an oncogen and teratogen. Benefits
associated with registered crop uses are considered to outweigh
oncogenic risks. There are adequate margins of safety for teratogenic
effects. Analysis of benefits and risks is provided in an Agency
position document accompanying the tolerance regulation published
December 21, 1983, in the FR for this pesticide.
5. SUMMARY OF MAJOR DATA GAPS
- Chronic non-rodent feeding (dog)
- Teratology: second species
DISCLAIMER: THE INFORMATION PRESENTED IN THIS CHEMICAL INFORMATION FACT
SHEET IS FOR INFORMATIONAL PURPOSES ONLY AND NOT TO BE USED TO FULFILL
DATA REQUIREMENTS FOR PESTICIDE REGISTRATION AND REREGISTRATION.