Registration of the New Active Ingredient Fenamidone Contained in the Pesticide Product Reason 500 SC Fungicide (EPA Reg. No.

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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: CERTIFIED MAIL RETURN RECEIPT REQUESTED Princy A. Jesudason, Ph.D. State Regulatory Affairs Bayer CropScience, LP P.O. Box Research Triangle Park, North Carolina Dear Dr. Jesudason: March 13, 2006 Re: Registration of the New Active Ingredient Fenamidone Contained in the Pesticide Product Reason 500 SC Fungicide (EPA Reg. No ) The New York State Department of Environmental Conservation (Department) has completed a technical review of the application and supplemental information submitted to date by Bayer CropScience, LP (BCS) in support of registration of the referenced pesticide product in New York State. Reason 500 SC Fungicide (EPA Reg. No ) contains the new active ingredient fenamidone (Chemical Code ). Reason 500 SC Fungicide (44.4% fenamidone) is a broad-spectrum foliar fungicide for control of certain plant diseases of potatoes and other tuberous and corm vegetables, tomatoes, onions and other bulb vegetables, lettuce (leaf and head), squash, melons, cucumbers and other cucurbit crops. Maximum application rates per growing season range from 22 fluid ounces Reason 500 SC Fungicide (0.71 pounds fenamidone/acre) for bulb vegetables and cucurbit crops to 24.6 fluid ounces product (0.80 pounds fenamidone/acre) for tomatoes, potatoes (except sweet potatoes) and other tuberous and corm vegetables, and lettuce (head and leaf). The Department hereby accepts Reason 500 SC Fungicide (EPA Reg. No ) for registration as a Restricted Use Pesticide product in New York State. Acceptable labeling bears the following text under the DIRECTIONS FOR USE section of the label: In the State of New York only; not for sale, distribution or use in Nassau or Suffolk County. A synopsis of the review and risk assessments follows: The application package was deemed complete for purposes of technical review on April 11, 2005 following one determination of incompleteness (1/06/2005). Pursuant to the review time frame specified in Environmental Conservation Law (ECL) , a registration decision date of September 8, 2005 was established. The decision date was subsequently waived in order to address the Department s concerns regarding impacts of certain degradates of fenamidone to groundwater/drinking water.

2 Princy A. Jesudason, Ph.D. 2. Toxicological, ecological, and environmental fate risk assessments were conducted for fenamidone and the end-use product Reason 500 SC Fungicide. Analytical methods for the determination of fenamidone in water and soil were also reviewed. TOXICOLOGICAL RISK ASSESSMENT: Neither the active ingredient fenamidone nor the formulated product Reason 500 SC were very acutely toxic to laboratory animals by the oral, dermal or inhalation routes of exposure. The active ingredient and the formulated product were also not very irritating to the eyes or skin (tested on rabbits), nor were they skin sensitizers (tested on guinea pigs). In an acute neurotoxicity feeding study in rats, fenamidone caused clinical signs and unsteady gait in females at 500 milligrams per kilogram body weight per day (mg/kg/day); the no-observed-effect level (NOEL) was 125 mg/kg/day. In a subchronic neurotoxicity feeding study, a decrease in brain weights in male rats was observed at a dose of mg/kg/day; the NOEL was 73.5 mg/kg/day. No clinical signs or pathological changes were reported in this study. In a subchronic feeding study in dogs, no effects from fenamidone were observed at a dose of 500 mg/kg/day, which was the highest dose tested, whereas in rats fed this chemical subchronically, increases in both liver weights and liver histopathology occurred in male and female animals at 68.3 and 83.3 mg/kg/day, respectively. The respective NOELs were 10.4 and 12 mg/kg/day. In a subchronic feeding study in mice, fenamidone caused an increase in liver weights and morphological changes in liver at and mg/kg/day in males and females, respectively; the respective NOELs were 44.5 and 54.1 mg/kg/day. Fenamidone caused some toxicity in chronic animal feeding studies. In a one-year dog feeding study, an increase in liver weight, triglycerides and biliary proliferation occurred in males, and an increase in alkaline phosphatase activity occurred in males and females at 100 mg/kg/day; the NOEL was 1,000 mg/kg/day. In a chronic feeding/oncogenicity study in rats, liver effects (increased weights and gross pathological changes) occurred doses of 47.7 and 60.9 mg/kg/day in males and females, respectively, while increased thyroid gland cell proliferation was observed at doses of 7.07 and 9.24 mg/kg/day for males and females, respectively. The respective NOELs were 2.83 and 3.63 mg/kg/day. In a chronic feeding/oncogenicity study in mice, a decrease in body weights, body weight gains and an increase in liver weight and liver histopatholgy were observed at doses of mg/kg/day (males) and mg/kg/day (females). The respective NOELs were 47.5 and 63.8 mg/kg/day. The United States Environmental Protection Agency (USEPA) Office of Pesticide Programs calculated an oral reference dose (RfD) for fenamidone of mg/kg/day based on the NOEL of 2.83 mg/kg/day in the chronic feeding/oncogenicity study in rats and an uncertainty factor of 1,000 (10x for interspecies differences, 10x for intraspecies variations and 10x data base uncertainty factor for lack of a developmental neurotoxicity study). This RfD value has not been adopted by the USEPA Integrated Risk Information System (IRIS). Fenamidone caused some developmental toxicity in the offspring of pregnant rats, but not pregnant rabbits, administered this chemical during organogenesis at doses that also caused maternal toxicity. In rats, an increased incidence of incomplete ossification and reduced fetal weights were reported at a maternal dose of 1,000 mg/kg/day; the NOEL was 150 mg/kg/day. Maternal toxicity (decreased body weight gain and food consumption) was reported at 1,000 mg/kg/day with a NOEL of 150 mg/kg/day. In rabbits, no developmental toxicity was reported

3 Princy A. Jesudason, Ph.D. 3. at the highest dose tested (100 mg/kg/day). Maternal animals showed an increase in liver weights at 30 mg/kg/day; the NOEL was 10 mg/kg/day. In a rat multigeneration reproduction study, a decrease in brain weights in adult female parental animals and female offspring was reported at a dose of 89.2 mg/kg/day; respectively; the NOEL was 5.5 mg/kg/day. Fenamidone did not cause oncogenic effects either in rat or mouse chronic feeding studies. This chemical gave predominantly negative results in genotoxicity studies. Based on the lack of evidence for carcinogenicity in rats and mice, USEPA classified fenamidone as not likely to be carcinogenic to humans. The USEPA established tolerances for fenamidone residues in or on cucurbit crops at 0.15 parts per million (ppm); tomatoes (1.0 ppm); tuberous and corm vegetables (0.02 ppm); onion, dry bulb (0.20 ppm); shallot, bulb (0.20 ppm); onion, green (1.5 ppm); and garlic, bulb (0.20 ppm). The chronic population adjusted dose (cpad) for fenamidone is mg/kg/day and has the same basis as the RfD. USEPA estimated that chronic dietary exposure to fenamidone would be 29% of the cpad for the general U.S. population and 69% for children one to two years old. This chronic exposure analysis is based on average field trial residues and projected percent crop treated estimates. The USEPA conducted a risk assessment for short- and intermediate-term combined dermal and inhalation exposures of workers to fenamidone. For mixers/loaders/applicators, the combined margins of exposure (MOEs) for short-term dermal and inhalation exposures were 2,260 and above. For intermediate-term dermal and inhalation exposures, the combined MOEs were 990 and above. The USEPA used a dermal absorption factor of 10% (based on study data in rats) and assumed 100% absorption for inhalation exposure. For these exposures, it was assumed that workers wore a single layer of clothing and gloves (the Reason 500 SC label requires long-sleeved shirt, long pants, shoes plus socks and chemical-resistant gloves). The NOEL used for estimating the short-term dermal and inhalation MOEs was 10.4 mg/kg/day from the subchronic feeding study in rats (increase in liver weights and liver histopathology). For the intermediate-term dermal and inhalation MOEs, the NOEL used was 5.5 mg/kg/day from the multigeneration reproduction study in rats (decrease in brain weights in adult females and female offspring). Generally, the USEPA considers MOEs of 100-fold or greater to provide adequate worker protection. For post-application exposures of workers involved in hand harvesting and thinning activities (determined by USEPA to be short-term tasks in duration), the estimated short-term MOE was about 350. The New York State Department of Health briefly reviewed the environmental fate data on fenamidone. These data indicate that this chemical and at least two of its degradates, denoted as RPA , and RPA , may have the ability to leach through certain soil types and contaminate groundwater; the adsorption coefficients (K oc ), depending on soil type, ranged from 259 to 494 for fenamidone, 17 to 36 for RPA , and 15 to 52 for RPA There are no chemical-specific federal or New York State drinking water/groundwater standards for fenamidone or its degradates. Based on their chemical structures, these compounds fall under the 50 microgram per liter (_g/l) New York State drinking water standard for unspecified organic contaminants (10 NYCRR Part 5, Public Water Systems). The New York State drinking water standard for the sum of unspecified organic contaminants and principal organic contaminants is 100 _g/l. If one uses the RfD for fenamidone (0.003 mg/kg/day) and procedures for deriving ambient water quality standards and guidelines based on non-oncogenic effects (6 NYCRR Part 702.5), a value of 21 _g/l can be derived.

4 Princy A. Jesudason, Ph.D. 4. The available information on fenamidone and Reason 500 SC Fungicide indicates that neither the active ingredient nor the formulated product was very acutely toxic, irritating or a sensitizer in laboratory animal studies. Furthermore, fenamidone was not carcinogenic in rats or mice. Although data from subchronic, chronic and developmental/reproductive studies showed that this chemical has the potential to cause some toxicity, the estimated risks to workers from use of Reason 500 SC Fungicide are within the range that is generally considered acceptable. In addition, dietary exposure of the general public to fenamidone on currently labeled crops is not expected to pose significant health risks. This chemical and some of its degradates, however, appear to have the potential to leach through soil and contaminate groundwater/drinking water. ECOLOGICAL RISK ASSESSMENT: 1. CHEMICAL BACKGROUND Reason 500 SC is a fungicide for use on potatoes and other tuberous and corm vegetables, tomatoes, onions and bulb vegetables, lettuce, and cucurbit crops. It contains the new active ingredient fenamidone, which is in the imidazolinone family of foliar fungicides. Its mode of action is to inhibit mitochondrial respiration of the target fungal cells by blocking electron transfer. Reason 500 SC contains 44.4% fenamidone, which is equivalent to 4.13 lbs active ingredient per gallon. The single application rate of fenamidone is 0.18 to 0.27 lbs per acre. It can be reapplied at five- to ten-day intervals. The maximum seasonal application rate of fenamindone is 0.53 lbs/acre on sweet potatoes, 0.71 lbs/acre on bulb and cucurbit vegetables, and 0.8 lbs/acre for all other applications. At those rates, three to four fenamidone applications can be made over a 15- to 40-day period. Fenamidone s solubility in water is C, and its log octanol-water partition coefficient is TOXICITY In general, fenamidone is not very toxic to mammals and birds. One study suggested that it might be more highly toxic to waterfowl, as represented by mallard ducks. This issue will be discussed in detail in Section 4. It is highly toxic, however, to aquatic life including fish and invertebrates. It is less toxic to marine fish than freshwater fish, but it is very highly toxic to marine invertebrates. A table summary of the ecotoxicological data for fenamidone follows:

5 Princy A. Jesudason, Ph.D. 5. Toxicity Summary Organism tested Test Risk thresholds rat mammalian acute oral, single dose, 49.2% AI LD 50 >5,000 mg/kg NOEL = 5,000 mg/kg rat mammalian 90 day feeding study LOEC = 1,000 ppm NOEC = 150 ppm rat mammalian 2 generation reproduction Parental LOEL= 1,000 ppm NOEL = 60 ppm Offspring LOEL = 1,000 ppm NOEL = 60 ppm bobwhite quail avian acute oral, single dose LD 50 >2,000 mg/kg NOEL = 2,000 mg/kg bobwhite quail avian 8 day dietary LC 50 >5,040 ppm NOEC = 5,040 ppm mallard duck avian 8 day dietary LC 50 >5,120 ppm NOEC = 2,580 ppm bobwhite quail avian reproduction LOEC >1,640 ppm NOEC = 1,640 ppm mallard duck avian reproduction LOEC 395 ppm NOEC <395 ppm bluegill sunfish warmwater fish 96 hour acute LC 50 = 0.74 mg/l NOEC = 0.57 mg/l rainbow trout coldwater fish 96 hour acute LC 50 = 0.74 mg/l NOEC = 0.35 mg/l fathead minnow fish early life stage NOTE: supplemental study, highest dose tested did not affect fish Daphnia magna freshwater invertebrate 48 hour acute Daphnia magna freshwater fish 28 day life cycle Sheepshead minnow marine/estuarine fish, 96 hour acute mysid shrimp marine/estuarine invertebrate, 96 hour acute oyster larvae marine/estuarine invertebrate, 96 hour acute Lemna gibba freshwater macrophyte, 5 day EC 50 growth Selenastrum FW green algae, 5 day EC 50 capricornutum population growth Navicula pelliculosa FW diatom, 5 day EC 50 population growth Skeletonema costatum marine diatom, 5 day EC 50 population growth Anabena flos-aquae FW blue-green algae, 5 day EC 50 population growth EC 50 >0.041 mg/l NOEC = mg/l LC 50 = mg/l NOEC = mg/l LOEC = mg/l NOEC = mg/l LC 50 = 2.5 mg/l NOEC = 1.1 mg/l LC 50 = mg/l NOEC = mg/l EC 50 = 0.12 mg/l EC 10 = mg/l EC 50 >0.88 mg/l NOEC = 0.88 mg/l EC 50 >0.82 mg/l NOEC = 0.82 mg/l EC 50 >mg/l NOEC = 0.9 mg/l EC 50 = 0.07 mg/l NOEC = mg/l EC 50 >0.94 mg/l NOEC = 0.94 mg/l

6 Princy A. Jesudason, Ph.D ENVIRONMENTAL FATE Fenamidone can be applied at rates of 0.18 to 0.27 lbs/acre for most crops. It can be applied three to four times at intervals ranging from five to ten days. The maximum seasonal application rate of fenamidone is 0.8 lbs/acre. Given the rate at which fenamidone breaks down, the accumulated loading that would result from lowest use rates (four applications of 0.18 lbs/acre every ten days) would be equivalent to a single application of 0.52 lbs/acre; whereas the accumulated loading that would result from the highest use rate (three applications of 0.27 lbs/acre every five days) would be equivalent to a single application of 0.73 lbs/acre. At these use rates, the following residues on treated vegetation would be expected to occur (see Table 1): Table 1. Expected residues of fenamidone in mg/kg of treated vegetation (ppm) Application Rates Vegetation type 0.18 lbs/a 0.27 lbs/a 0.52 lbs/a 0.73 lbs/a Long grass Short grass broadleaf vegetation (forage) fruit Fenamidone is broken down primarily by microbial degradation. Its field dissipation rate ranged from a half-life of 8.7 days on a sandy loam soil in Washington to 81.5 days on a sandy loam soil in California. The geometric mean half-life of these and other field dissipation studies in Florida and North Dakota was 24 days. Three major degradation products resulted from microbial breakdown of fenamidone. Some were more persistent, but all were significantly less toxic. Fenamidone is removed from water by photolysis, sedimentation, and microbial degradation. In two studies, the rate of photolysis in water ranged from half-lives of 5 to 5.8 days. In aerobic, sandy-clay-loam sediment-water system, fenamidone partitioned slowly from water to sediment. The half-lives were 21 days for water and 108 days for the entire system; the half-life in sediment was not calculated. In an aerobic sandy-loam sediment system, the halflives of fenamidone were 12, 85, and 67 days in water, sediment, and the entire system, respectively. In an anaerobic sediment-water system, fenamidone partitioned rapidly to sediments with a half-life of about a day for the water column. It degraded from the sediments much more slowly than in aerobic sediments, however, with a half-life of 1,386 days. 4. RISK ASSESSMENT The AVTOX model showed, when used as labeled, fenamidone did not exceed any acute or chronic risk avian risk thresholds. The MAMTOX model showed that, when used as labeled, fenamidone did not exceed any acute mammalian risk thresholds. The chronic/reproductive NOELs for mammals consuming short grass or long grass that was treated at the highest maximum seasonal application rate (three applications of 0.27 lbs ai/acre five days apart, or 0.73 lbs ai/acre) were exceeded marginally (RQs = 1.1 and 1.5, respectively). These risks were not considered significant. The exceedances were marginal, and the risk threshold barely exceeded the NOEL. The high application rate is unlikely to occur, and the residues are based on

7 Princy A. Jesudason, Ph.D. 7. applications to target plants, i.e., agricultural commodities. Nontarget wildlife will not be exposed to treatment levels this high from consuming nontarget vegetation exposed by drift or overspray. The PONDTOX model was used to estimate risks to aquatic organisms. Fenamidone s log K OW is 2.8, so runoff percentages of 1%, 3%, and 5% from a ten acre treated field into one acre ponds one foot, three feet, and six feet deep were modeled. The worst-case scenario was fenamidone being applied at the maximum seasonal rate (0.73 lbs/acre) directly on to bare ground (no foliar intercept), and running off at the highest percent runoff rate of 5%. Under this scenario, fenamidone exceeds no freshwater fish risk thresholds regardless of water depth. The Daphnia magna LC 50 and NOEC were exceeded in one foot deep pond, and the NOEC was also exceeded in the three foot deep pond. Chronic risk thresholds (LOEC and NOEC) for the fathead minnow were exceeded in the one foot deep pond. All risk thresholds in all pond depths were exceeded for mysid shrimp. A more reasonable risk scenario was also modeled. Fenamidone being applied at the maximum seasonal rate (0.73 lbs/acre) to target vegetation. A foliar intercept value of 25% was selected. The average percent runoff rate of 3% was used. In this exposure scenario, the Daphnia magna NOEC was marginally (RQ = 1.1) exceeded only in the one foot pond depth. Mysid shrimp chronic LOEC and NOEC were exceeded in the one foot pond depth (RQ = 1.7 and 3.5, respectively), and the chronic NOEC was exceeded in the three foot pond depth (RQ = 1.7). At higher rates of foliar intercept, the risk threshold exceedances disappear. Some impacts to the freshwater diatom Skeletonema costatum were also noted in both scenarios. No impacts from the use of single application rates were noted. One problem was noted with the fenamidone data support package. The mallard duck reproductive study was not acceptable, and as a condition of federal registration, the study must be repeated. The study found impacts to number and survival of hatchlings and female weight gain at the lowest dose tested, 395 ppm fenamidone in diet. The new study will test lower concentrations to determine the no effects concentration. A similar study was done with bobwhite quail, but reproductive impairments were not observed at similar dietary exposures. An eight week old mallard duck weighs about 2.5 kg, and normally consumes about 10% of its body weight daily or 0.25 kg. At the maximum seasonal application rate of 0.8 lbs fenamidone/acre, the highest residues, 100 ppm, would be expected to occur on short grass. Assuming that a duck would eat short grass, this application is nearly only a quarter of the 395 ppm dietary exposure at which some reproductive impairments were observed. This suggests that risks to waterfowl from eating vegetation exposed to fenamidone via drift or overspray is probably slight. 5. RISK ANALYSIS Fenamidone could potentially put aquatic invertebrates at risk, if applied to bare ground at the maximum application rate with the shortest interval between applications, and a rainstorm removed 5% of the applied material. This is unlikely to occur, as fenamidone is a foliar fungicide and is not applied to bare ground. Even at the worst case scenario, the exceedances noted were generally small. If introduced into the water via runoff, fenamidone will be degraded by both photolysis and sediment sorption. Under the reasonable model scenario, risks are greatly

8 Princy A. Jesudason, Ph.D. 8. reduced. Used as labeled, Reason 500 SC should not put nontarget aquatic organisms at risk and is unlikely to have any adverse ecological impacts. ANALYTICAL METHODS: Analysis methods for determination of fenamidone and its metabolites in water and soil were acceptable with a comment regarding use of a needle spike to correct recoveries for metabolites RPA and RPA in the soil method. The modification states that this would only be done if the initial LOQ recovery was outside of the % acceptance criteria. Review of the attached validation report indicated that this was not necessary during the validation procedure. The Department will not expect to see any such corrected recovery information from actual sample analyses and, as such, will not accept the same. ENVIRONMENTAL FATE RISK ASSESSMENT: Reason 500 SC Fungicide is a broad spectrum fungicide containing 44.4% by weight fenamidone (or 4.13 lb ai/gallon) for control of certain plant diseases of potatoes and other tuberous and corm vegetables, tomatoes, onions and other bulb vegetables, leaf and head lettuce, squash, melons, cucumbers and other cucurbit crops. The application rate ranges from to lb ai/acre/application; three applications may be applied for a maximum application rate of 0.8 lb ai/acre/year. For cucurbits and onions and other bulb vegetables, the application rate is limited to lb ai/acre/application; four applications may be applied for a total of 0.71 lb ai/acre/year. Each application must be alternated with a fungicide from a different resistance management group. The Data Evaluation Record (DERs) reports were performed by Dynamac Corporation, and approved by the USEPA. Staff also referred to the Canadian Regulatory Note (REG ) for Fenamidone Technical Fungicide and Reason 500 SC Fungicide found at Major Transformation Products: RPA methyl-5-phenyl-3-phenylaminoimidazolidin-2,4-dione RPA methyl-2-methylthio-3-(4-nitrophenylamino)-5-phenyl-3,5-dihydroimidazol-4-one RPA methyl-2-methylthio-5-phenyl-3,5-dihydroimidazol-4-one RPA methyl-3-(4-nitrophenylamino)-5-phenylimidazolidine-2,4-dione RPA methyl-2-methylthio-3-(2-nitrophenylamino)-5-phenyl-3,5-dihydroimidazol-4-one RPA methyl-3-(2-nitrophenylamino)-5-phenylimidazolidine-2,4-dione RPA (S)-5-methyl-5-phenylimidazolidine-2,4-dione [S-enantiomer of RPA717879] RPA methyl-5-phenylimidazolidine-2,4-dione S-enantiomers: RPA is the S-enantiomer of RPA RPA is the S-enantiomer of RPA RPA is the S-enantiomer of RPA RPA is the S-enantiomer of RPA RPA is the S-enantiomer of RPA RPA is the S-enantiomer of RPA RPA is the S-enantiomer of RPA

9 Princy A. Jesudason, Ph.D. 9. Hydrolysis: In a study (MRID ) that was found acceptable, fenamidone had a half-life of 41.8 days at ph 4; days at ph 5; days at ph 7 and 27.6 days at ph 9. No major transformation products were found at phs 5 or 7. Solubility: Fenamidone has a solubility of 7.8 mg/l in water at 20 degrees C. Soil Photolysis: According to the Canadian Regulatory Note (REG ) for Fenamidone Technical Fungicide and Reason 500 SC Fungicide, fenamidone was resistant to photodegradation under normal environmental conditions. Aqueous Photolysis: Two studies were performed using different labeled rings. In the phenyl imidazolinone moiety labeled ring (MRID ), fenamidone has a half-life of 25.5 hours under continuous artificial light. The predicted environmental phototransformation half-life derived from the laboratory measured half-life was calculated at 5.0 days of cloudless summer sunlight at 20 to 50 degrees north latitude. Two major transformation products were found: RPA at 35.6% and RPA at 13.4%. In the second study (MRID ), the halflife was 28.8 hours under continuous artificial light. The predicted environmental phototransformation half-life derived from the laboratory measured half-life was calculated at 5.8 days of cloudless summer sunlight at 20 to 50 degrees north latitude. One major transformation product was found: RPA at 9.25%. Both studies together fully satisfied the Subdivision N Guidelines for Aerobic Soil Metabolism: In a study found to be acceptable (MRID ): % OM ph Half-life Biphasic 1 st Sandy loam biphasic 1 st 4.8 days Half-life Biphasic 2 nd Biphasic 2 nd days Major Transformation Products RPA % RPA % RPA % Sandy loam days days RPA % RPA % RPA % RPA % Loam days 86.8 days RPA % RPA % Aerobic Water-Sediment: In a sandy clay loam soil flooded with river water under forced air, the half-life in water was days, the half-life in the sediment was not determined, the halflife in the entire system was days with one major transformation product RPA at 21.73%. In a sandy loam soil (MRID ) flooded with stream water under forced air, the half-life in water was days, the half-life in the sediment was days, and the half-life in the entire system was days with one major transformation product RPA at 13.52%. In a loam soil (MRID ) flooded with stream water under forced air, the half-life in water was days, the half-life in the sediment was not determined, and the half-life in the entire system was days with no major transformation products. These two studies together were found to be acceptable. Anaerobic Soil Metabolism: In a study found to be acceptable (MRID ), in a clay sediment flooded with river water and incubated under nitrogen, the half-life in water was less

10 Princy A. Jesudason, Ph.D. 10. than one day, the half-life in the sediment was not determined, and the half-life in the entire system was 1, days. No major transformation products were found. Adsorption/Desorption: In a study found to be acceptable (MRID ): Adsorption Koc Desorption Koc ph % OC Silt loam 486 9, Sandy loam 494 3, Loam 313 1, Sandy clay loam 387 1, Silt loam 259 3, Field Dissipation: In a study found to be acceptable (MRID ): T _ ph % OC Major Transformation Products Florida sand 22.4 days RPA % North Dakota loam 20.5 days None California 81.5 days None loamy sand Washington loamy sand 8.7 days None TRANSFORMATION PRODUCTS Aerobic Metabolism of RPA (RPA ): This study (MRID ), along with the aerobic metabolism study of the parent (MRID ) were found to be acceptable: T_ Major Transformation Products Sand days None Clay loam days CO2 Loam days CO2 According to the Canadian Regulatory Note (REG ) for Fenamidone Technical Fungicide and Reason 500 SC Fungicide, the half-life for this degradate was 110 to 128 days. Adsorption/Desorption of RPA (RPA ): In a study found to be acceptable (MRID ): Adsorption Koc Desorption Koc Silt loam Sandy loam 36 5,189 Loam Sandy clay loam 28 1,249 Silt loam

11 Princy A. Jesudason, Ph.D. 11. Adsorption/Desorption of RPA (RPA ): In a study found to be acceptable (MRID ): Desorption Koc, Day 0 Desorption Koc, Day 3 Desorption Koc, Day 10 Loam Not determined 130 2,414.8 Sand Not determined 4,779 1, Clay loam 2,665 1,117 1, Silt loam Not determined Not determined Not determined Aerobic Metabolism of RPA (RPA ): According to the Canadian Regulatory Note (REG ) for Fenamidone Technical Fungicide and Reason 500 SC Fungicide, the half-life for this degradate was 28 to 255 days. Adsorption/Desorption of RPA (RPA ): In a study found to be acceptable (MRID ): Adsorption Koc Desorption Koc ph % OC Silt loam Sandy loam Loam 33 1, Clay 15 1, Silt loam 21 5, Adsorption/Desorption of RPA (RPA ): In a study found to be acceptable (MRID ): Adsorption Koc Desorption Koc ph % OC Silt loam , Sandy loam 746 2, Loam 746 1, Clay Silt loam 347 3, Adsorption/Desorption of RPA (RPA ): In a study found to be acceptable (MRID ): Adsorption Koc Desorption Koc ph % OC Silt loam , Sandy loam 622 3, Loam 450 1, Clay Silt loam 261 1, Adsorption/Desorption of RPA (RPA ): In a study found to be acceptable (MRID ) the reviewer calculated K oc s were:

12 Princy A. Jesudason, Ph.D. 12. Adsorption Koc Desorption Koc ph % OC Silt loam 264 3, Sandy loam Silt loam 98 1, Sandy clay loam Loam 393 1, Surface Water Advisories: The following surface water advisories appear on the final product label: This product may contaminate water through drift of spray in wind. This product has a high potential for runoff for several months or more after application. Poorly draining soils and soils with shallow water tables are more prone to produce runoff that contains this product. A level, well maintained vegetative buffer strip between areas to which this product is applied and surface water features such as ponds, streams and springs will reduce the potential for contamination of water from rainfall-runoff. Runoff of this product will be reduced by avoiding applications when rainfall is forecasted to occur within 48 hours. Groundwater Advisory: An October 2, 2002 USEPA Environmental Fate & Effects Division memorandum indicated that this product required a groundwater advisory on the label as follows: A major metabolite of this chemical has properties and characteristics associated with chemicals detected in groundwater. The use of this chemical in areas where soils are permeable, particularly where the water table is shallow, may result in groundwater contamination. This advisory did not appear on the Reason 500 SC Fungicide (EPA Reg. No ) labeling accompanying the Notice of Registration dated October 8, Computer Modeling: Running LEACHP on Riverhead soil for the parent using a K oc of 494, a half-life of 4.8 days and an application rate of 0.8 lb fenamidone/acre/year, the model projected two peaks of about 1 X 10-8 ppb. Running the degradate RPA , with a K oc of 36 at 35% of the parent, or 0.17 lb ai/acre/year, and a half-life of 105 days, the model projected cyclical peaks of about 7.3 to 16.5 ppb. Running the degradate RPA with a K oc of 32 at 13% of the parent, or 0.07 lb ai/acre/year, and a half-life of 28 days, the model projected cyclical peaks of about 0.4 to 1.1 ppb. Canada Review: The Regulatory Note (REG ) for Fenamidone Technical Fungicide and Reason 500 SC Fungicide for temporary registration on late blight on potatoes. In the review, Canada stated: The results from Level 1 LEACHM modeling indicate that fenamidone is expected to reach groundwater sources of drinking water. LEACHM predicts acute (yearly peak) and chronic (yearly average) concentrations at the 90 th percentile. By factoring in surface runoff into reservoirs and dugouts, Level 1 PRZM/EXAMS modelling predicts acute (yearly peak) and chronic (yearly average) concentrations at the 90 th percentile. These values are considered to be upper bound concentrations in surface water that potentially may be used as a source of drinking water. Groundwater Risk Assessment Summary: Environmental fate data indicate that fenamidone and at least two of its degradates have the ability to leach through certain soil types and contaminate groundwater. In the absence of groundwater monitoring data, LEACHP modeling was conducted. Based on these simulations, the parent fenamidone does not appear to pose a risk to groundwater. However, LEACHP modeling predicts that the degradate RPA is likely to impact groundwater in vulnerable aquifers.

13 Princy A. Jesudason, Ph.D. 13. MITIGATION: BCS mutually agreed to waive the registration decision date and submitted a response to the groundwater concerns expressed in the Department s technical issues letter (August 18, 2005). As noted by BCS, the maximum application rate for the degradates used in the LEACHP simulations has been corrected for differences in molecular weight. The absence of a Groundwater Advisory statement for the degradate RPA on the final product label was attributed to a refined drinking water assessment. USEPA removed the requirement for the groundwater advisory statement in their final environmental and ecological risk assessment, dated July 16, However, this environmental fate risk assessment contains the following comment: The terminal degradate of fenamidone is RPA , which forms only in soils and water-sediment systems under aerobic conditions. It is very persistent (half-life as high as 462 days in aerobic soils, laboratory studies). Because of this persistence, it has a potential to accumulate in soils over time. It is very mobile and has a high potential to leach to groundwater or reach surface water by runoff. Once in surface water, RPA predominantly stays in the water column. Due to the Department s continuing concern regarding the potential for the fenamidone degradate RPA to impact vulnerable groundwater resources, BCS proposed addition of the following text to the DIRECTIONS FOR USE section of the label: In the State of New York only; not for sale, distribution or use in Nassau or Suffolk County. On January 31, 2006, the Department received a copy of the notification (12/15/05) to USEPA regarding this minor labeling change together with updated product labeling. A number of mitigating factors and benefits were considered in the evaluation of Reason 500 SC Fungicide for use in upstate New York. Major use of this product in upstate New York is expected to occur on soils which are less susceptible to leaching. USEPA granted reduced risk status to fenamidone for use in potatoes, tomatoes, cucurbits, bulb vegetables and lettuce. As the first commercial product of the imidazolinone class of fungicides, Reason 500 SC Fungicide will provide an alternative fungicide that can be used in resistance management programs with other fungicides that have alternative modes of action. REGISTRATION ACTION: The Department accepts Reason 500 SC Fungicide (EPA Reg. No ) for registration as a Restricted Use Pesticide product in New York State. Acceptable labeling bears the following text under the DIRECTIONS FOR USE section of the label: In the State of New York only; not for sale, distribution or use in Nassau or Suffolk County. Enclosed for your files are the Certificate of Pesticide Registration and New York State stamped ACCEPTED labeling. Reason 500 SC Fungicide contains a YES in the RESTRICTION column on the Certificate and is classified as a Restricted Use Pesticide under rules and regulations 6 NYCRR Part (e). As such, this product is restricted in its purchase, distribution, sale, use and possession in New York State. According to Department regulations specified in 6 NYCRR 326.3(a): It shall be unlawful for any person to distribute, sell, offer for sale, purchase for the purpose of resale, or possess for the purpose of resale, any restricted pesticide unless said person shall have applied for, and been issued a commercial permit. If you require information regarding a commercial

14 Princy A. Jesudason, Ph.D. 14. permit, please contact Maggie O Neil, Chief, Pesticide Reporting and Certification Section, at (518) The Pesticide Reporting Law (PRL) requires all certified commercial pesticide applicators to report information annually to the Department regarding each pesticide application they make. Commercial pesticide retailers are required to report all sales of restricted pesticide products and sales of general use pesticide products to private applicators for use in agricultural crop production. If no sales are made within New York State, a report still must be filed with the Department indicating this is the case. Information relating to the PRL or annual report forms is available at the Department s website at or from the Pesticide Reporting and Certification Section, at (518) Please note that a proposal by Bayer CropScience, LP or any other registrant to register a product containing fenamidone, whose labeled uses are likely to increase the potential for significant exposure to humans or impact to the environment, would constitute a major change in labeled (MCL) use pattern. An application for a MCL must be accompanied by a new application fee and meet the requirements specified in 6 NYCRR Part Please contact Samuel Jackling, Chief of our Pesticide Product Registration Section, at (518) , if you have any questions. Enclosures Sincerely, Maureen P Serafini Maureen P. Serafini Director Bureau of Pesticides Management cc: w/enc. - N. Kim/D. Luttinger, NYS Dept. of Health R. Zimmerman/R. Mungari, NYS Dept. of Ag. & Markets W. Smith, Cornell University, PSUR