Benefluralin (Elanco/Eli Lilly). Also known as Benefin. March 1985 Herbicide Profile (PMEP).

FLUORIDE ACTION NETWORK PESTICIDE PROJECT

Benfluralin (Elanco/Eli Lilly). Also known as Benefin. March 1985 Herbicide Profile.

From the Pesticide Management Education Program (PMEP) at Cornell University

Benefin (Balan, Balfin) Herbicide Profile 3/85

CHEMICAL NAME: N-Butyl-N-ethyl-a,a,a-trifluoro-2,6-dinitro-p- toluidine (56)

TRADE NAME(S): Balan, Balfin (58)

FORMULATION(S): Concentrate 10%, 20% (Pel-Tech). Liquid (1.5 lb/gal) for agricultural purposes; 2.5% granular for turf (56).

TYPE: Dinitrotoluidine herbicide

BASIC PRODUCER(S): Elanco Products Co. Div. of Eli Lilly and Co. 740 South Alabama St. Indianapolis, IN 46285

STATUS: General use

PRINCIPAL USES: For control of annual grasses and broadleaf weeds in direct-seeded lettuce, established turf, seeded alfalfa, red clover, birdsfoot trefoil, and ladino clover (56).

APPLICATION METHOD(S): Benefin is a preemergence herbicide and must be soil incorporated within 4 hours (western United States) or 8 hours (eastern United States) after application with equipment that breaks up large clods and mixes the soil thoroughly; e.g., PTO-driven cultivators, hoes or tillers; double disc, rolling cultivator, or bed conditioner. Application and incorporation can be preplanting or postplanting. Surface applications of benefin 2.5G for weed control in established turfgrassses are also registered (58).

I. EFFICACY Grass and broadleaf weeds controlled are: annual bluegrass (Poa annua), barnyardgrass (Echinochloa crus-galli), crabgrasses (Digitaria sp.), crowfootgrass (Dactylocetenium aegyptium), fall panicum (Panicum dichotomiflorum), foxtails (Setaria sp.), goosegrass (Eleusine indica), seedling johnsongrass (Sorghum halepense), junglerice (Echinochloa colonum), ryegrass (Lolium multiflorum), sandbur (Cenchrus incertus), Texas panicum (Panicum texanum), carpetweed (Mollugo verticillata), chickweed (Stellaria media), knotweed (Polygonum aviculare), lambsquarters (Chenopodium album), pigweeds (Amaranthus sp.), purslane (Portulaca oleracea), redmaids (Calandrinia ciliata), and Florida pusley (Richardia scabra) (58).

Will not control established weeds (56).

Tolerant weeds include nightshade, mallows, nutgrass, cocklebur, groundsel, and ragweed (8b).

Incorporation less than 2 inches deep may result in erratic weed control. Do not use on muck or peat soils (8b).

Season-long control can be expected. Kills weed seeds as they germinate. Rainfall is not required to activate the chemical. Shallow cultivations will not reduce the effectiveness (8b).

II. PHYSICAL PROPERTIES

MOLECULAR FORMULA: C13 H16 F3 N3 O4 (62)

MOLECULAR WEIGHT: 335.3 (62)

PHYSICAL STATE: Yellow-orange crystalline solid (pure compound) (62)

ODOR: No appreciable odor (pure compound) (58)

MELTING POINT: 65-66.5 C (pure compound) (62)

BOILING POINT: 121-122 C at 0.5 mmHg (pure compound) (58)

VAPOR PRESSURE: 52 mPa at 30 C (pure compound) (62)

SOLUBILITY: <1 mg/l water at 25 C (pure compound) (62) III. HEALTH HAZARD INFORMATION

OSHA STANDARD: NA

NIOSH RECOMMENDED LIMIT: NA

ACGIH RECOMMENDED LIMIT: NA

TOXICOLOGY

A. ACUTE TOXICITY

DERMAL: No apparent toxicity to skin for technical benefin. Solvent system in liquid concentrate may be irritating to skin (58).

ORAL: LD0 = >10,000 mg/kg (adult rat), >2,000 mg/kg (dog, chicken, rabbit) (technical benefin) (58). LD50 = 800 mg/kg (newborn rat, technical benefin) (58). LD50 = 5,000* mg/kg (adult rat, Balan LC; * 5 ml/kg, toxicity due entirely to solvent system) (58).

INHALATION: No apparent danger through inhalation of technical benefin (58).

EYES: Solvent system in liquid concentrate may be irritating to eyes (58).

B. SUBACUTE AND CHRONIC TOXICITY:

Safe levels after 3 months feeding:

Rats - 1,250 ppm in diet.

Dogs - 500 ppm (12.5 mg/kg in capsule administered daily) (58).

In 2-yr feeding trials NEL for rats was 1,000 mg/kg diet. LC50 for bluegill fingerlings is 0.37 mg/l (62).

IV. ENVIRONMENTAL CONSIDERATIONS

Behavior In Or On Soils

1. Adsorption and leaching characteristics in basic soil types: Benefin is strongly adsorbed on soil and shows negligible leaching. Organic matter and clay content of the soil influence the application rate for herbicidal activity.

2. Microbial breakdown: No direct evidence is available that microorganisms are responsible for the degradation and disappearance of benefin. Indirect evidence suggest that microorganisms do play a role in the disappearance of benefin from soil.

3. Loss from photodecomposition and/or volatilization: Benefin is slightly volatile. Material remaining on the soil surface can be subject to photodecomposition.

4. Resultant average persistence at recommended rates: Recommended application rates give season long weed control. Fall-seeded grain crops planted in soil that received benefin applications the preceding spring have not been injured under warm, moist conditions.

References

Golab, T., R.J. Herberg, J.V. Gramlick, A.P. Raun, and G.W.

Probst. 1970. Fate of benefin in soils, plants, artificial rumen fluid and the ruminant animal. J. Agr. Food Chem. 18:838-844.

Probst, G.W., Golab, T., Wright, W.L.: in "Herbicides", Vol. 1, 2nd ed. Kearney, P.C. Kaufman, D.D., Ed., Marcel Dekker, New York, 1975, pp. 453-500.

Parka, S.J. and Q.F. Soper. 1977. The physiology and mode of action of the dinitroaniline herbicides. Weed Sci. 25:79-87 (58).

Acute oral LD50 = >2,000 mg/kg (bobwhite quail, mallard duck); LC50 for bluegill fingerlings is 0.37 mg/l (62).

No hazard to mammals and birds; toxic to fish if placed directly in water. Physical properties of compound (strong adsorption on soil) and application methods (soil incorporation) preclude possibility of hazard to fish in recommended usage (58).

V. EMERGENCY AND FIRST AID PROCEDURES

The chemical information provided below has been condensed from original source documents, primarily from "Recognition and Management of Pesticide Poisonings", 3rd ed. by Donald P. Morgan, which have been footnoted. This information has been provided in this form for your convenience and general guidance only. In specific cases, further consultation and reference may be required and is recommended. This information is not intended as a sub- stitute for a more exhaustive review of the literature nor for the judgement of a physician or other trained professional.

If poisoning is suspected, do not wait for symptoms to develop. Contact a physician, the nearest hospital, or the nearest Poison Control Center.

KNOWN OR SUSPECTED ADVERSE EFFECTS: Slightly to moderately irritating to skin, eyes, and mucous membranes. These agents do not uncouple oxidative phosphorylation (25).

SKIN CONTACT: WASH contaminated SKIN with soap and water (25).

INGESTION: INGESTIONS of SMALL amounts (less than 10 mg/kg body weight) occurring less than an hour before treatment, are probably best treated by:

A. SYRUP OF IPECAC, followed by 1-2 glasses of water. Dose for adults and children over 12 years: 30 ml. Dose for children under 12 years: 15 ml.

B. ACTIVATED CHARCOAL Administer 30-50 gm as a slurry in tap water, after vomiting stops.

C. SODIUM OR MAGNESIUM SULFATE, 0.25 gm/kg in tap water, as a cathartic (25).

EYE CONTACT: FLUSH contaminated EYES with copious amounts of fresh water for 15 minutes (25).

NOTES TO PHYSICIAN: INGESTIONS of LARGE amounts (more than 10 mg/kg) occurring less than an hour before treatment, should probably be treated by gastric lavage:

A. INTUBATE stomach and ASPIRATE contents.

B. LAVAGE stomach with slurry of ACTIVATED CHARCOAL IN 0.9% saline. Leave 30-50 gm activated charcoal in the stomach before withdrawing tube.

C. SODIUM SULFATE, 0.25 gm/kg in tap water, as a cathartic.

CAUTION: Hydrocarbons (kerosene, petroleum distillates) are included in some formulations of these chemicals. Ingestion of very LARGE AMOUNTS may cause CNS depression. In this case, IPECAC IS CONTRAINDICATED. Also, gastric intubation incurs a risk of HYDROCARBON PNEUMONITIS. For this reason observe the following precautions:

(1) If the victim is unconscious or obtunded and facilities are at hand, insert an ENDOTRACHEAL TUBE (cuffed, if available) prior to gastric intubation.

(2) Keep victim's HEAD BELOW LEVEL OF STOMACH during intubation and lavage (Trendelenburg, or left lateral decubitus, with head of table tipped downward). Keep victim's head turned to the left.

(3) ASPIRATE PHARYNX as regularly as possible to remove gagged or vomited stomach contents.

INGESTIONS occurring MORE THAN an HOUR before treatment are probably best treated only by ACTIVATED CHARCOAL, 30-50 gm, and SODIUM or MAGNESIUM SULFATE, 0.25 gm/kg, as described above. There are no specific antidotes for these chemicals. Because manifestations of toxicity do occasionally occur in peculiarly predisposed individuals, MAINTAIN CONTACT with victim for at least 72 hours so that unexpected adverse effects can be treated promptly (25).

VI. FIRE AND EXPLOSION INFORMATION

Technical material is not flammable. For the emulsifiable concentrates, use ordinary precautions for volatile solvents (58). Flash point is 78 F (Balan) (56).

VII. COMPATIBILITY

No incompatibilities have been experienced with hard water or other pesticides. The emulsifiable concentrates can be successfully impregnated on granular fertilizers. Benefin is not corrosive (58). Corrosive (Balan) (56).

VIII. PROTECTIVE MEASURES

STORAGE AND HANDLING: Avoid freezing; store above 40 F. Do not store near heat or flame. Do not get in eyes. Wear goggles or face shield when handling concentrate. Do not contaminate foodstuffs or feed. Keep out of reach of children (56).

IX. PROCEDURES FOR SPILLS AND LEAKS IN CASE OF EMERGENCY, CALL, DAY OR NIGHT (800) 424-9300 PESTICIDE TEAM SAFETY NETWORK/CHEMTREC

X. LITERATURE CITED

8b. Thomson, W.T. 1981. Agricultural chemicals - book 2: herbicides. Revised ed. Thomson Publications, Fresno, CA. 274 pp.

25. Morgan, D.P. 1982. Recognition and management of pesticide poisonings, 3rd ed. U.S. Environmental Protection Agency, Washington, DC. 120 pp.

56. Farm Chemicals Handbook, 70th ed. 1984. R. T. Meister, G. L. Berg, C. Sine, S. Meister, and J. Poplyk, eds. Meister Publishing Co., Willoughby, OH.

58. Weed Science Society of America, Herbicide Handbook Committee. 1983. Herbicide handbook of the weed science society of America, 5th ed. Weed Science Society of America, Champaign, IL. 515 pp.

62. The Pesticide Manual: A World Compendium, 7th ed. 1983. C.R. Worthing, ed. The British Crop Protection Council, Croydon, England. 695 pp.

3/4/85

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