Adverse Effects:

Anemia
Blood
Body Weight Decrease
Bone
Brain
Cancer: Possible Human Carcinogen - LIVER
Endocrine: Adrenal
Endocrine: Pituitary
Endocrine: Thymus
Endocrine: Thyroid
Kidney
Liver
Spleen

Environmental Effects:

Highly Toxic to fish

Bioaccumulation Potential

Phototoxic. Oxyfluorfen may pose risks to animals not conveyed by standard guideline toxicity studies because its mode of action suggests it may be more toxic in the presence of light (phototoxic)

Sub-chronic and chronic risks to terrestrial birds and mammals present a serious concern. These toxic effects may be manifested as reproductive, developmental, and hemolytic consequences.

Contamination Incidents:

Aug 2000: Fifteen Mile Creek near the Dalles Dam, Oregon. Truck carring 20,000 pounds crashed into bridge spilling herbicide into creek yards from where it enters the Columbia River.

March 1996: Madera County, CA. Aerial drift onto 90-100 acres of almonds. Estimated damage $520,000 to $760,000.

May 1996: Desha County, AR. Aerial drift onto 160 acres of rice.

March 1996: Kern County, CA. Aerial drift onto 10 acres of oranges.

Australia, Canada, Hungary, India, New Zealand, Philippines, Portugal, South Africa, US 

Australia:
Grape

• Jan 11, 2002 - Overview of Oxyfluorfen Risk Assessment

• Dec 18, 2001 - Revised Human Health Risk Assessment.

• Dec 11, 2001 - Revised Environmental Fate and Effects Division Preliminary Risk Assessment for the Oxyfluorfen RED

• Aug 8, 2001 - Toxicology chapter for RED document.

• March 7, 2001 - Phototoxic Pesticides: Memo Requesting Phototoxicity Study Protocol for Light-Dependent Peroxidizing Herbicides

Rationale for US EPA to add Oxyfluorfen to the Toxic Release Inventory

Oxyfluorfen is a phenoxyphenyl-type herbicide. Several chronic oral toxicity studies suggest that oxyfluorfen may be hepatotoxic. Hepatic effects (e.g. increased absolute liver weight, necrosis, regeneration, and hyperplastic nodules) were observed in mice fed diets containing greater than 3 mg/kg/day oxyfluorfen for 20 months (the NOEL was 0.3 mg/kg/day). Based on these findings, an oral RfD value of 0.003 mg/kg/ day was derived. This study was supported by other chronic feeding studies that demonstrated increases in liver weight, alkaline phosphatase activity, and bile pigmented hepatocytes (the LOEL was 15 mg/kg/day; the NOEL was 2.5 mg/kg/day) in dogs, and minimal hypertrophy of centrilobular hepatocytes (the LOEL was 40 mg/kg/day; the NOEL was 2 mg/kg/day) in rats. EPA believes that there is sufficient evidence for listing oxyfluorfen on EPCRA section 313 pursuant to EPCRA section 313(d)(2)(B) based on the hepatotoxic effects of this chemical.

The estimated chronic MATC values for fish and daphnids are 9 ppb and 20 ppb oxyfluorfen, respectively. The estimated log Kow is 6.1. EPA believes that there is sufficient evidence for listing oxyfluorfen on EPCRA section 313 pursuant to EPCRA section 313(d)(2)(C) based on the environmental toxicity data and potential for bioaccumulation for this chemical.

Ref: USEPA/OPPT. Support Document for the Health and Ecological Toxicity Review of TRI Expansion Chemicals. U. S. Environmental Protection Agency, Washington, DC (1993). As cited by US EPA in: Federal Register: January 12, 1994. Part IV. 40 CFR Part 372. Addition of Certain Chemicals; Toxic Chemical Release Reporting; Community Right-to-Know; Proposed Rule.

Use Profile

Oxyfluorfen is a diphenyl-ether herbicide used for broad spectrum pre- and post-emergent control of annual broadleaf and grassy weeds in a variety of tree fruit, nut, vine, and field crops. The largest agricultural markets in terms of total pounds active ingedient are wine grapes and almonds. There are also non-agricultural ornamental and forestry uses. Oxyfluorfen is also used for weed control in landscapes, patios, driveways, and similar areas in residential sites.
Ref: Oct 30, 2002 - RED Fact Sheet. US EPA.

From 1992 to 1997 the use of oxyfluorfen increased by 54%, from an estimated 458,000 pounds active ingredient in 1992 to an estimated 705,000 lbs active ingredient in 1997 (Gianessi and Silvers, 2000). Much of this increase was driven by changes in usage on four agricultural crops. An estimated 2% of broccoli acreage in California was treated with oxyfluorfen in 1992; that estimate increased to 15% of broccoli acreage in California in 1997. Treated acreage of Texas onions increased from 15% to 100% and treated acreage of California onions increased from 55% to 67% between 1992 to 1997. Much of this increase in treated broccoli and onion acreage was due to the end of production of DCPA (a pre-emergence herbicide). An estimated 12% of cotton acreage in Louisiana was treated with oxyfluorfen in 1992; that estimate increased to 20% of cotton acreage in Louisiana in 1997. This change was attributed to the adoption of planting a "stale" seedbed (similar to conventional planting, except a ÒburndownÓ herbicide, such as oxyfluorfen, is required to remove weeds). Use on California pistachio acreage increased from an estimated 44% to 62% between 1992 and 1997. During this time interval, the total acreage in pistachios increased by 78%, thus resulting in a large total poundage increase in oxyfluorfen usage.
Ref: US EPA. Revised Environmental Fate and Effects Division Preliminary Risk - December 11, 2001.

Proposed Tolerance Action. EPA is proposing to modify certain tolerances for the herbicide oxyfluorfen and is proposing to establish new tolerances. The regulatory actions proposed in this document are in follow-up to the Agency's reregistration program under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), and tolerance reassessment program under the Federal Food, Drug, and Cosmetic Act (FFDCA) section 408(q). EPA has issued a post-FQPA REDs for oxyfluorfen.

Comments must be received on or before July 2, 2007.

Based on available data that showed residues of oxyfluorfen as high as 0.03 ppm in or on mint hay, EPA determined that the tolerance on mint hay (peppermint and spearmint) should be decreased from 0.1 to 0.05 ppm. Therefore, the Agency is proposing in 40 CFR 180.381(a) to revise the commodity terminology for mint hay into separate tolerances on peppermint, tops and spearmint, tops and decrease each tolerance to 0.05 ppm.

Based on available exaggerated (5x to 7x MTDB) cattle feeding data that showed residues of oxyfluorfen as high as < 0.003 ppm in milk, 0.007 ppm in fat, < 0.003 ppm in meat, < 0.003 ppm in kidney, and < 0.003 ppm in liver, EPA expected residues below the LOQ (0.01 ppm) in milk, fat, meat, and meat byproducts at the 1x MTDB for cattle. The Agency determined that the tolerances on milk and the fat, meat and meat byproducts of cattle, goats, hogs, horses, and sheep should be set at the LOQ and decreased from 0.05 to 0.01 ppm. Therefore, EPA is proposing in 40 CFR 180.381(a) to decrease the tolerances on milk; cattle, fat; cattle, meat; cattle, meat byproducts; goat, fat; goat, meat; goat, meat byproducts; hog, fat; hog, meat; hog, meat byproducts; horse, fat; horse, meat; horse, meat byproducts; sheep, fat; sheep, meat; and sheep, meat byproducts to 0.01 ppm.

Based on available exaggerated (2.0x MTDB) poultry feeding data that showed residues of oxyfluorfen as high as 0.024 ppm in eggs, 0.163 ppm in fat, 0.004 ppm in meat, and 0.006 ppm in liver, EPA expected residues of 0.012 ppm in egg, 0.082 ppm in fat, 0.002 ppm in meat, and 0.003 ppm in liver at the 1x MTDB for poultry. The Agency determined that the tolerances should be decreased on egg from 0.05 to 0.03 ppm, meat and meat byproducts from 0.05 to 0.01 ppm, and increased on fat from 0.05 to 0.2 ppm. Therefore, EPA is proposing in 40 CFR 180.381(a) to decrease the tolerances on egg to 0.03 ppm, poultry, meat to 0.01 ppm, poultry, meat byproducts to 0.01 ppm, and increase the tolerance on poultry, fat to 0.2 ppm. The Agency determined that the increased tolerance is safe; i.e., there is a reasonable certainty that no harm will result from aggregate exposure to the pesticide chemical residue. Based on available data that showed oxyfluorfen residues from use of oxyfluorfen on grass grown for seed in Oregon and Washington were not detectable (< 0.03 ppm) in or on grass forage, hay, and seed screenings, EPA determined that the reassessed animal commodity tolerances are adequate to cover any residue contribution from regional registration uses of oxyfluorfen on grasses grown for seed and tolerances should be established on grass forage, hay, and seed screenings at 0.05 ppm. Therefore, the Agency is proposing to establish tolerances in 40 CFR 180.381(c) on grass, forage; grass, hay; and grass, seed screenings; each at 0.05 ppm.

In addition, EPA is proposing to revise commodity terminology in 40 CFR 180.381 to conform to current Agency practice as follows:

``banana (including plantain)'' to ``banana''
``coffee, bean'' to ``coffee, bean, green;'' `
`corn, grain'' to ``corn, field, grain'' and ``corn, pop, grain;''
``onion, dry bulb'' to ``onion, bulb;''
``taro, corm and leaves'' to ``taro, corm'' and ``taro, leaves.

Moreover, it should be noted that use of oxyfluorfen on plantains is covered by the existing tolerance at 0.05 ppm for banana under 40 CFR 180.1(g), and there is no need to establish a separate tolerance on plantains at 0.05 ppm. Also, because use of oxyfluorfen on garlic is covered by the existing tolerance at 0.05 ppm for onion bulb under 40 CFR 180.1(g), there is no need to establish a separate tolerance on garlic at 0.05 ppm as had been recommended in the RED.

Notice of Receipt of Requests to Voluntarily Cancel Certain Pesticide Registrations.

Requests to Voluntarily Cancel Certain Pesticide Registrations.

Cancellation of Pesticides for Non-payment of Year 2005 Registration Maintenance Fees.

Availability of Court Orders in Washington Toxics Coalition v. EPA Litigation. The Order (with some exceptions) enjoins, vacates and sets aside EPA's authorization of certain pesticides' uses within 20 yards for ground applications and 100 yards for aerial applications, adjacent to salmon supporting waters in California, Oregon and Washington, effectively establishing buffer zones around those waters. This order applies to 38 pesticides, including the fluoridated
Diflubenzuron, Oxyfluorfen, Trifluralin.
The Court's January 22 Order, which carries an effective date of February 5, 2004, and other related materials, including the Court's previous Orders, are available at:
January 22, 2004
August 8, 2003
July 16, 2003
July 2, 2002