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The information in this profile may be out-of-date.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

Oxyfluorfen

Trade and Other Names: Trade names include Goal, Koltar and RH-2915.

Regulatory Status: Oxyfluorfen is a slightly to practically non-toxic compound in EPA toxicity class III [2]. Products containing oxyfluorfen must bear the Signal Word WARNING on the label because some formulated products may have higher toxicities. It is a General Use Pesticide (GUP).

Chemical Class: Not Available

Introduction: Oxyfluorfen is a selective pre- and post-emergent herbicide used to control certain annual broadleaf and grassy weeds in vegetables, fruit, cotton, ornamentals, and on non-crop areas (e.g. rail- and highway right-of-ways). It is a contact herbicide and light is required for it to affect target plants. It is available in emulsifiable concentrate and granular formulations.

Formulation: It is available in emulsifiable concentrate and granular formulations.

Toxicological Effects:

• Acute toxicity: Oxyfluorfen is practically nontoxic by ingestion, with reported oral LD50 values of 5000 mg/kg in both rats and dogs, and 2700 to 5000 mg/kg in mice [1,58]. The dermal LD50 is greater than 5000 mg/kg in both rats and rabbits, also indicating slight toxicity by this route [58]. It causes no skin irritation in rabbits, no skin sensitization in guinea pigs, and moderate eye irritation in rabbits [58]. However, Goal and other formulations may show severe skin and eye irritant properties, and may be skin sensitizers [58]. The 4-hour inhalation LC50 for the technical product is not available, but that for Goal 1.6E is greater than 22.64 mg/L, indicating practically no toxicity via this route [58].
• Chronic toxicity: Effects on the liver have been observed in long-term feeding studies with rats, mice, and dogs [56,108].
• Reproductive effects: In a developmental study with rats given doses of 10, 100, or 1000 mg/kg/day by gavage, decreased implantation, increased resorption, and lower fetal survival was seen at the 1000 mg/kg level. Toxic effects on the mothers were also seen at this dose [108]. At 5 mg/kg/day, there was decreased survival of fetuses and decreased maternal and fetal weights [108]. It does not appear likely that oxyfluorfen will cause reproductive effects in humans at likely levels of exposure.
• Teratogenic effects: In a developmental study with rabbits, 30 mg/kg/day, the highest dose tested, produced an increase in fused sternal bones in the fetuses as well as toxic effects on the mothers [108]. These data suggest oxyflurofen may have teratogenic effects, but only at very high doses.
• Mutagenic effects: Mutagenicity tests on rats, mice and on bacterial cell cultures have produced mixed results. However, unscheduled DNA synthesis assays have been negative [58,108]. Due to the conflicting results, it is not possible to determine the mutagenic potential of oxyfluorfen.
• Carcinogenic effects: In a 20-month study with mice fed 0.3, 3, or 30 mg/kg/day, doses at and above 3 mg/kg/day produced non-significant increases in both benign and malignant liver tumors in male mice [58,108]. No increased tumor formation was seen in female mice at any dose [58,108]. No carcinogenic effects were observed in a 23-year study with rats fed doses 2 mg/kg/day, nor in dogs at doses of 3 mg/kg/day [58,108]. These data suggest that oxyfluorfen is not carcinogenic.
• Organ toxicity: The liver appears to be the main target organ, based on long-term feeding studies.

• Fate in humans and animals: Because oxyfluorfen is highly hydrophobic, it may have the potential to bioconcentrate in animal fatty tissues [108].

Ecological Effects:

• Effects on birds: Oxyfluorfen is practically nontoxic to birds; the reported oral LD50 values are greater than 2200 mg/kg in bobwhite quail, and greater than 4000 mg/kg in mallard duck [108]. The dietary 8-day dietary LC50 values are greater than 5000 ppm in bobwhite quail, and 4000 ppm in mallard ducks [58,109]. Dietary concentrations as high as 100 ppm had no effect on reproduction in mallards or bobwhite quail [109].
• Effects on aquatic organisms: Oxyfluorfen is highly toxic to aquatic invertebrates, freshwater clams, oysters, aquatic plants, and fish. The reported 96-hour LC50 values are 200 ug/L in bluegill sunfish, 410 ug/L in rainbow trout, 400 ug/L in channel catfish, 150 ug/L in fathead minnow, and 32 ug/L in grass shrimp and oysters [58,109]. Its 96-hour LC50 in freshwater clams is 10 ug/L. The 96-hour LC50 for the product Goal 2E in Daphnia magna, a small freshwater crustacean, is 1500 ug/L [58,109]. Oxyfluorfen accumulated up to 13 mg/kg (13,000 ug/kg) in bluegill sunfish exposed to 10 ug/L for 40 days [108]. This represents a bioconcentration factor (BCF) of 1300. The BCF in channel catfish was 700 to 5000 in one 30-day study [109]. These results indicate a low to moderate potential for bioaccumulation in aquatic species.
• Effects on other organisms: Oxyfluorfen is nontoxic to honeybees, with a reported oral LC50 of greater than 10,000 ppm [58].

Environmental Fate:

• Breakdown in soil and groundwater: Oxyfluorfen is moderately persistent in most soil environments, with a representative field half-life of about 30 to 40 days [58,110]. Oxyfluorfen is not subject to microbial degradation or hydrolysis [58,11]. The main mechanism of degradation in soils may be photodegradation and evaporation/codistillation in moist soils [58,110]. In laboratory studies, its soil half-life was 6 months, indicating very low rates of microbial degradation [58,11]. Oxyfluorfen is very well-sorbed to most soils [11]. Soil binding is highest in soils with high organic matter and clay content [58,11]. Once oxyfluorfen is adsorbed to soil particles, it is not readily removed [58]. It is practically insoluble in water, and therefore is unlikely to be appreciably mobile in most instances, unless the sorptive capacity of the soil is exceeded. Oxyfluorfen did not leach below 4 inches in any soil except sand [11].
• Breakdown in water: In water, oxyfluorfen is rapidly decomposed by light [3]. Because oxyfluorfen is nearly insoluble in water and has a tendency to adsorb to soil, it will be sorbed to suspended particles or sediments [58,109].
• Breakdown in vegetation: There is very little movement of oxyfluorfen within treated plants. It is not readily metabolized by plants, but since it is not readily taken up by roots, residues in plants are generally very low [58]. Residues of oxyfluorfen accumulated in carrots and oats grown on previously treated fields, but not in cotton or lettuce [109].

Physical Properties:

• Appearance: Oxyfluorfen is a white to orange or red-brown crystalline solid with a smoke-like odor [1,108].
• Chemical Name: 2-chloro-alpha,alpha,alpha-trifluoro-p-tolyl 3-ethoxy-4-nitrophrnyl ether [1]
• CAS Number: 42874-03-3
• Molecular Weight: 361.70
• Water Solubility: 0.1 mg/L [1]
• Solubility in Other Solvents: v.s. in most organic solvents (e.g acetone, cyclohexanone, isophorone ) [1]
• Melting Point: 84-85 C [1]
• Vapor Pressure: 0.026 mPa @ 25 C [1]
• Partition Coefficient: 4.4683 [1]
• Adsorption Coefficient: 100,000 (estimated) [11]

Exposure Guidelines:

• ADI: Not Available
• MCL: Not Available
• RfD: 0.003 mg/kg/day [13]
• PEL: Not Available
• HA: Not Available
• TLV: Not Available

Basic Manufacturer:

Rohm and Haas Co.
Agricultural Chemicals
100 Independence Mall West
Philadelphia, PA 19106

• Phone: 215-592-3000
• Emergency: Not Available
  

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.