February 3, 2006 CERTIFIED MAIL RETURN RECEIPT REQUESTED

Transcription

1 New York State Department of Environmental Conservation Division of Solid and Hazardous Materials Bureau of Pesticides Management, 11th Floor 625 Broadway, Albany, New York Phone: (518) FAX: (518) Website: February 3, 2006 CERTIFIED MAIL RETURN RECEIPT REQUESTED Mr. Don Johnson State Registration Manager FMC Corporation, Agricultural Products Group 1735 Market Street Philadelphia, Pennsylvania Dear Mr. Johnson: Re: Withdrawal of Application to Register the New Active Ingredient Sulfentrazone Contained in the Pesticide Product Spartan 4F Herbicide (EPA Reg. No ) The New York State Department of Environmental Conservation (Department) acknowledges your request for withdrawal from consideration for registration of the referenced pesticide product. Spartan 4F Herbicide (EPA Reg. No ) contains the new active ingredient sulfentrazone (Chemical Code ). The Department has completed a technical review of the application (received February 2, 2005) and supplemental information submitted to date by FMC Corporation, Agricultural Products Group (FMC) in support of the subject pesticide product. A synopsis of the review and available risk assessments follows. Spartan 4F Herbicide (39.6% sulfentrazone) is a flowable formulation containing four pounds active ingredient per gallon. Product is labeled for application to soil as a preplant incorporated treatment or as a preemergence (to weed and crop) surface application on soybeans, sugarcane, sunflowers, tobacco, cabbage (processing only), dry peas (chickpea and dry field pea), horseradish, lima beans (succulent) and mint for control of certain broadleaf, grass and sedge weeds. Use on lima beans (succulent) is limited to the state of Tennessee. The maximum allowable Spartan 4F use per acre per 12-month period ranges from eight fluid ounces product (0.25 pounds sulfentrazone) for dry peas, horseradish and sunflowers to 12 fluid ounces product (0.375 pounds sulfentrazone) for soybeans, sugarcane, tobacco, cabbage and mint.

2 Mr. Don Johnson 2. The total allowed usage per 12-month period includes all applications made to the field per 12- month interval. This includes fallow treatments, burndown treatments, planting time and all in-season treatments. The 12-month period is considered to begin upon the initial Spartan 4F Herbicide application. The subject application package was deemed complete for purposes of technical review on August 24, 2005 following two determinations of incompleteness. Pursuant to the review time frame specified in Environmental Conservation Law (ECL) , a registration decision date of January 21, 2006 was established. Health effects and environmental fate risk assessments were conducted for sulfentrazone and the Spartan 4F Herbicide formulated product. An ecotoxicity risk assessment was not produced for this product. Analytical methods for the determination of sulfentrazone in water and soil were deemed complete and acceptable following the receipt of additional information submitted on November 22, HEALTH EFFECTS RISK ASSESSMENT: Neither the active ingredient sulfentrazone nor the formulated product Spartan 4F Herbicide was very toxic in acute oral, dermal or inhalation exposure studies in laboratory animals, nor were they very irritating to the eyes and skin (tested on rabbits). Also, neither material was a skin sensitizer (tested on guinea pigs). Sulfentrazone caused some toxicity in chronic animal feeding studies. In dogs, rats and mice, sulfentrazone caused hematological effects, characterized primarily by a decrease in hemoglobin levels, at doses of 61.2, 82.8 and milligrams per kilogram body weight per day (mg/kg/day), respectively, in males, and 61.9, 67 and 198 mg/kg/day in females. The respective-no-observed-effect levels (NOELs) in male dogs, rats and mice were 24.9, 40 and 93.9 mg/kg/day, whereas in females, the respective NOELs were 29.6, 36.4 and mg/kg/day. Sulfentrazone caused some developmental toxicity in the offspring of pregnant rabbits and rats administered this compound during organogenesis. In a rabbit oral developmental toxicity study, an increase in fetal resorptions and decreases in live fetuses per litter and fetal weight occurred at a dose of 250 mg/kg/day; the NOEL was 100 mg/kg/day. In this study, maternal toxicity characterized by reduced body weight gain, was reported at a dose level of 250 mg/kg/day, with a NOEL of 100 mg/kg/day. In a rat oral developmental toxicity study, retarded fetal skeletal development and decreased fetal weight were observed at a dose of 25 mg/kg/day; the NOEL was ten mg/kg/day. Maternal toxicity, characterized by an increase in relative spleen weight and splenic extramedullary hematopoiesis, occurred at 50 mg/kg/day with a NOEL of 25 mg/kg/day. In another rat developmental toxicity study, but this time conducted by the dermal route of exposure, sulfentrazone caused an increase incidence of fetal abnormalities (incompletely ossified lumbar vertebral arches, hypoplastic or wavy ribs) at a dose of 250 mg/kg/day; the NOEL was 100 mg/kg/day. No maternal toxicity was observed at the highest dose tested, which was 250 mg/kg/day. In a multigeneration reproduction study in rats, sulfentrazone caused an increased duration of gestation in both generations and testicular damage in the F 1 generation at 40 and 33 mg/kg/day for females and males, respectively; the respective NOELs were 16 and 14 mg/kg/day. Parental toxicity which was characterized by a decrease in body weight gain and body weights was also observed at 33 and 40

3 Mr. Don Johnson 3. mg/kg/day for male and female animals respectively, with respective NOELs of 14 and 16 mg/kg/day. The United States Environmental Protection Agency (USEPA) Office of Pesticide Programs established an oral reference dose (RfD) of 0.14 mg/kg/day based on a NOEL of 14 mg/kg/day from the multigeneration reproduction study in rats and an uncertainty factor of 100. This RfD has not yet been adopted by the USEPA s Integrated Risk Information System (IRIS). Sulfentrazone did not cause oncogenic effects in either rat or mouse chronic feeding studies. In addition, genotoxicity studies on sulfentrazone gave negative results. Based on the lack of evidence for carcinogenicity in rats and mice, the USEPA classified sulfentrazone as not likely to be carcinogenic to humans. The USEPA established tolerances for sulfentrazone residues in or on soybeans at 0.05 parts per million (ppm); asparagus, lima beans, potatoes, peas/beans, each at 0.15 ppm; cabbage (0.20 ppm); and field corn (forage, grain and stover at 0.20, 0.15 and 0.30 ppm, respectively). The chronic population adjusted dose (cpad) for sulfentrazone is 0.14 mg/kg/day and has the same basis as the RfD. The USEPA estimated that the chronic dietary exposure to sulfentrazone residues would be one percent of the cpad for each of the following population subgroups: general U.S. population; infants less than one year old; children one to two years old; children three to five years old. This chronic exposure analysis is based on the conservative assumptions that 100% of the crops are treated and that these treated crops contain tolerance level residues. The USEPA conducted a risk assessment for dermal and inhalation exposure of workers to sulfentrazone from its use on turf grass, including golf courses, and a variety of crops for which tolerances have been established, as noted above. For mixers/loaders/applicators, the margins of exposure (MOEs) for dermal and inhalation exposures were estimated to range from 200 to 5,700 and 2,400 to 15,000, respectively, for use on crops. For use on turf, the estimated dermal and inhalation MOEs were 91,000 and 187,000, respectively. For these estimates, it was assumed that workers wore a long-sleeved shirt, long pants, shoes and socks and gloves (the Spartan 4F Herbicide label requires the use of this personal protective equipment). The NOEL used for estimating the dermal MOE was 100 mg/kg/day from the dermal developmental toxicity study in rats, and for estimating the inhalation MOE, the NOEL used was 14 mg/kg/day from the multigeneration reproduction study in rats. For post-application exposures of workers to sulfentrazone-treated crops, the estimated MOE was 450. For golfers, the MOEs ranged from 1,200,000 to 2,000,000, whereas for post-application exposures to sulfentrazone-treated residential lawns, the estimated MOE for adults was 12,000 and for children, estimated MOEs ranged from 8,500 to 64,000. Generally, the USEPA considers MOEs of 100-fold or greater to provide adequate protection for workers, short-term nonworkers (e.g., golfers) and the general public. The New York State Department of Health (NYSDOH) briefly reviewed the environmental fate data for sulfentrazone. These data indicate that this chemical may have the ability to leach through certain soil types and contaminate groundwater; the adsorption coefficients (K oc ) depending on soil type, ranged from 26 to 77. These values suggest that sulfentrazone has a high mobility through some soils. In addition, the Spartan 4F product label contains the groundwater advisory, This chemical is known to leach through soil into groundwater under certain conditions as a result of label use. Use of this chemical in areas where soils are permeable, particularly where the water table is shallow, may result in

4 Mr. Don Johnson 4. groundwater contamination. There are no chemical-specific federal or New York State drinking water/groundwater standards for sulfentrazone. Based on its chemical structure, this compound falls under the 50 microgram per liter New York State drinking water standard for unspecified organic contaminants (10 NYCRR Part 5, Public Water Systems). The available information on sulfentrazone and Spartan 4F Herbicide indicates that neither the active ingredient nor the formulated product was very acutely toxic, irritating or a sensitizer in laboratory animal studies. Furthermore, sulfentrazone was not carcinogenic in rats or mice. Although data from chronic and developmental/reproductive studies showed that this chemical has the potential to cause some toxicity, the estimated risks to workers from the use of the Spartan 4F product or to workers and the general public from post-application exposure to sulfentrazone are within the range that the USEPA generally considers acceptable. In addition, dietary exposure of the general public to sulfentrazone from currently labeled crops was determined by the USEPA to not pose significant health risks. Since there were clear NOELs/LOELs and the dietary exposure assessment has a reliable and conservative basis, USEPA did not include an additional uncertainty factor when deriving the cpad to account for potentially greater fetal sensitivity. If an extra ten-fold uncertainty factor was incorporated in the cpad, dietary exposure estimates would still not exceed this value, indicating acceptable risks. Given the above, NYSDOH did not object to the registration of Spartan 4F Herbicide on the basis of direct human health risks. Sulfentrazone, however, appears to have the potential to leach through soil and contaminate groundwater/drinking water. ECOLOGICAL EFFECTS RISK ASSESSMENT: The Department s Bureau of Habitat had no basis to object to registration of Spartan 4F Herbicide, however, an ecological effects risk assessment was not completed for this product. ENVIRONMENTAL FATE RISK ASSESSMENT: Sulfentrazone is also referred to as methanesulfonamide or F6285 in the data package submitted for review. The application rate is based upon the soil texture (coarse, medium or fine) and the percent of organic matter, with the higher application rates for fine soils and soils with >3% organic matter. The product is applied to the soil, and can be applied as preplant, preemergent, or post-plant treatment. The product requires moisture to be activated, or may be incorporated into the soil to be activated if no irrigation is present. The product is taken up by the germinating seeds and seedlings. The amount of product available for uptake is determined by soil type, amount of organic matter and soil and irrigation water ph. Sulfentrazone adsorbs to clay and organic matter, and is thus not available for uptake. As soil ph decreases, the amount of product available for uptake decreases. Also, as the ph of the irrigation water decreases, the amount of sulfentrazone available for uptake increases.

5 Mr. Don Johnson 5. The following table shows the maximum allowable Spartan 4F use on soybeans per acre per 12- month period based on soil texture and percent organic matter. Coarse soils are sand, loamy sand and sandy loam. Medium soils are sandy clay loam, sandy clay, loam, silt loam, and silt. Fine soils are silty clay loam, silty clay, clay loam and clay. Fluid Ounces of Product to be applied for Soybeans % Organic Matter COARSE SOIL MEDIUM SOIL FINE SOILS < > Solubility: Sulfentrazone has a solubility of 780 mg/l. Hydrolysis: According to the June 16, 2003 EFED memorandum for Section 3 Registration, sulfentrazone is not susceptible to hydrolysis with half-lives of 143 days at ph 5; 207 to 375 days at ph 7; and 348 days at ph 9 in sterile buffered solutions. Aqueous Photolysis: In an acceptable study (MRID ), sulfentrazone photodegraded with a halflife of 12 hours in ph 5, one hour in ph 7 and one hour in ph 9 sterile buffer solutions. Major degradates were found at ph 7; des-dichloromonohydroxy sulfentrazone at 12.8%; 2,4-dihydroxy sulfentrazone at 11.7%. Methyl triazole was the major degradation product, reaching 25.7% of the applied at the end of ten days exposure. Soil Photolysis: According to the June 16, 2003 EFED memorandum for Section 3 Registration, sulfentrazone is very stable to photolysis on sand and sandy loam soils with half-lives of 98 and 161, respectively. Aerobic Soil Metabolism: In an acceptable study (MRID ), sulfentrazone degraded with a halflife of 535 to 555 days in a sandy loam soil (1.6% OM and ph 6.7) and 534 to 541 days in a silty clay loam soil (4.2% OM and ph 6.6). One major degradate was found, F carboxylic acid at 10.8%. Anaerobic Aquatic Metabolism: In an acceptable study (MRID ), sulfentrazone degraded very slowly in a flooded loamy sand sediment with an estimated half-life of nine years. Adsorption/Desorption: In a partially acceptable study (MRID ), the DER states that radiolabeled sulfentrazone was mobile in columns of sandy loam. Two degradates were found, both minor, but USEPA indicated that they were very mobile. They were 3-hydroxymethyl F6285 and 3- carboxylic acid F6285.

6 Mr. Don Johnson 6. This study was scientifically sound but did not meet Subdivision N Guidelines (MRID ). %OM ph Koc adsorption Koc desorption sandy loam silt loam silty clay loam sand Terrestrial Field Dissipation: In an acceptable study (MRID ), sulfentrazone dissipated in the 0 to six-inch layer of a bareground clay loam soil with a half-life of one year. Sulfentrazone was detected in the six- to 12-inch soil layer at four to nine ppb at 61 through 451 days and 20 ppb at 531 days. At all sampling intervals, sulfentrazone averaged <4 ppb at soil at depths below 12 inches. Degradate 3- carboxylic acid F6285 averaged <11 ppb in the 0 to six-inch depth and <2 ppb below the six-inch depth at all sampling intervals. In an acceptable study (MRID ), sulfentrazone dissipated in the 0 to six-inch layer of a bareground clay loam soil with a half-life of 1.5 years. Sulfentrazone was detected in the 0 to six-inch soil layer 67 to 95 ppb at 453 to 554 days. Trace amounts <3 ppb were detected at the six- to 12-inch depth. Degradate 3-carboxylic acid F6285 ranged between three to 13 ppb in the 0 to six-inch depth in all soil samples collected between day three and day 554. In an acceptable study (MRID ), sulfentrazone dissipated with an estimated half-life of 121 days in the entire 48-inch soil column of a plot of loamy sand soil. Sulfentrazone was detected in the 0 to sixinch soil layer at 13.4 to 22 ppb 103 to 368 days. Sulfentrazone was detected in the soil to a depth of 48 inches, with maximum average concentrations of 36.7 ppb in the six- to 12-inch depth, 10.9 ppb in the 12- to 18-inch depth, 6.6 ppb in the 18- to 24-inch depth, 5.2 in the 24- to 30-inch depth, 10.8 ppb in the 30- to 36-inch depth, three ppb in the 36- to 42-inch depth, and one ppb in the 42- to 48-inch depth. Degradate 3-carboxylic acid F6285 ranged between averaged <11.5 ppb in soil from the 0 to six-inch depth and <7.3 in soil collected from depths below six inches at all sampling intervals. Prospective Small-Scale Groundwater Study: According to the information presented, FMC is currently conducting three prospective groundwater monitoring studies at three sites. These studies were required based on the original registration for soybeans. Selection of the three sites was to represent the 75 th, 85 th and 95 th percentile vulnerability of groundwater in the projected use area. A single small-scale prospective groundwater monitoring study was previously conducted prior to the conditional registration of sulfentrazone, and, in spite of having to be terminated early because of an irrigation accident, confirmed the leaching of sulfentrazone and its acid derivative to groundwater.

7 Mr. Don Johnson 7. Preliminary results from the three groundwater studies suggest that sulfentrazone and the acid degradate are very mobile. USEPA Comments: In a March 22, 1996 EF&GWB Memorandum, USEPA states: No decision has been made at this time regarding what additional measures might be necessary to mitigate any potential for sulfentrazone use to contaminate groundwater. Recommendations will be made upon completion of the Agency s review of the final report for the small-scale prospective groundwater monitoring study submitted by the registrant. Modeling: The Department s groundwater model (LEACHP) using Riverhead soil, a K oc of 29, a half-life of 535 days, and the maximum application rate of lb ai/acre/year predicts breakthrough in four months and cyclical sulfentrazone concentrations ranging from 20 to 110 ppb over the ten-year modeling cycle. The Department s groundwater model using Howard soil, a K oc of 40, a half-life of 534 days, and the maximum application rate of lb ai/acre/year predicts breakthrough in year two and sulfentrazone concentrations ranging from 50 to 90 ppb over the ten-year modeling cycle. Label Statements: Spartan 4F Herbicide contains the following text under the Environmental Hazards section of label: Groundwater Advisory: This chemical is known to leach through soil into groundwater under certain conditions as a result of label use. Use of this chemical in areas where soils are permeable, particularly where the water table is shallow, may result in groundwater contamination. Do not use on coarse soils classified as sand, which have less than one percent organic matter. Surface Water Advisory: Sulfentrazone can contaminate surface water through spray drift. Under some conditions, sulfentrazone may also have a high potential for runoff into surface water (primarily via dissolution in runoff water), for several to many months post-application. These include poorly draining or wet soils with readily visible slopes toward adjacent surface waters, frequently flooded areas, areas overlying extremely shallow groundwater, areas with in-field canals or ditches that drain to surface water, areas not separated from adjacent surface waters with vegetated filter strips, and areas over-lying tile drainage systems that drain to surface waters. Given sulfentrazone s long half-life, very low Kocs, the modeling projections and the ground and surface water advisories, it appears that use of Spartan 4F Herbicide as labeled will have a significant negative impact on water quality in New York State. DISCUSSION: After reviewing all the information submitted by FMC in support of registration of the referenced pesticide product, the Department has determined that use of Spartan 4F Herbicide as labeled would result in deterioration of groundwater/drinking water resources in New York State. Sulfentrazone has high leaching potential and the environmental fate data, preliminary small-scale prospective groundwater monitoring data, and LEACHP simulations confirm this chemical s ability to leach in

8 Mr. Don Johnson 8. vulnerable and less vulnerable soils. Due to the above-mentioned concerns, FMC has requested withdrawal of the application to register Spartan 4F Herbicide (EPA Reg. No ) in New York State. The Department is aware that FMC is currently conducting three small-scale prospective groundwater monitoring studies at three different sites classified as approximating a 95 th, 85 th and 75 th percentile vulnerability for potential groundwater contamination. FMC anticipates in the near future USEPA will allow termination of these studies so a final report can be written and submitted for review. Upon completion of USEPA s review of these studies, FMC intends to submit a new application and fee for registration of Spartan 4F Herbicide (EPA Reg. No ) in New York State. Please note that the application should be accompanied by USEPA s review documents and any other information that would address the Department s concerns regarding the leaching potential of sulfentrazone. You are reminded that any unregistered pesticide product may not be sold, offered for sale, distributed, or used in New York State. Please contact Samuel Jackling, Chief of our Pesticide Product Registration Section, at (518) , if you have any questions. Sincerely, Maureen P Serafini Maureen P. Serafini Director Bureau of Pesticides Management cc: N. Kim/D. Luttinger, NYS Dept. of Health R. Zimmerman/R. Mungari, NYS Dept. of Ag. & Markets W. Smith, Cornell University, PSUR