May 15, DELIVERY CONFIRMATION (Co. No. 352) Mr. Tim McPherson DuPont Crop Protection PO Box 30 Newark, DE Dear Mr.

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1 New York State Department of Environmental Conservation Division of Solid and Hazardous Materials Bureau of Pesticides Management Pesticide Product Registration Section 625 Broadway, Albany, New York Phone: (518) Fax: (518) Website: Alexander B. Grannis Commissioner May 15, 2009 DELIVERY CONFIRMATION (Co. No. 352) Mr. Tim McPherson DuPont Crop Protection PO Box 30 Newark, DE Dear Mr. McPherson: Re: Registration of a Major Change in Labeling for DuPont Matrix FNV Herbicide (EPA Reg. No ) Containing the Active Ingredient Rimsulfuron (Active Ingredient Code ) The New York State Department of Environmental Conservation (Department) has evaluated your application and supplemental materials received to date in support of the registration of the above-mentioned pesticide product in New York State. Rimsulfuron was initially registered by the Department on August 15, 1997 for use on potatoes and field corn. As a condition of registration, aerial application was prohibited in New York State. The major change in labeling application for DuPont Matrix FNV Herbicide proposes to add citrus fruit, stone fruit, tree nuts, pome fruit, and grapes as labeled use sites in New York State. Subsequent to the original submission, DuPont Crop Protection (DuPont) requested that the Department include non-crop uses such as roadsides, industrial plant sites and utility substations as part of the pending review. DuPont Matrix FNV Herbicide contains 25.0 % rimsulfuron as a dry flowable formulation. It is labeled for broadcast and banded application. Aerial application of the subject product is prohibited. The maximum labeled use rates are the same per application and per year ( pounds of active ingredient per acre). The application was determined to be complete for purposes of technical review on July 29, Pursuant to the review time frames set forth in Environmental Conservation Law , a decision date of December 26, 2008 was established. On December 23, 2008, Department staff indicated by to DuPont Crop Protection that the Department would not be supporting registration at such time due to concerns regarding data deficiencies with regard to environmental fate characteristics of rimsulfuron and its degradates. As a result, DuPont requested, and was granted, a waiver of the legislatively mandated decision. A formal letter detailing the data deficiencies was sent to DuPont on February 2, On March 17, 2009, the Department received DuPont s response to the concerns expressed in the letter. This response included additional information regarding environmental fate not previously submitted to the Department. The additional information sufficiently mitigated the Department s concerns regarding the additional proposed uses on agricultural sites. However, the Department continues to have concerns regarding the proposed use on noncrop use sites including roadsides, highway medians, industrial plant sites, and utility substations. The

2 Mr. Tim McPherson 2 following technical reviews were performed to evaluate the risk of the additional uses of rimsulfuron. Human Health Risk Assessment: New York State Department of Health (NYSDOH) staff previously reviewed rimsulfuron and the formulated product DuPont Matrix FNV Herbicide for the registration of Matrix, Basis, and Basis Gold Herbicides; DuPont Matrix FNV Herbicide is identical in formulation to the Matrix Herbicide product. Neither rimsulfuron nor the formulated product was very toxic in acute oral, dermal or inhalation exposure studies in laboratory animals. In addition, neither was a skin sensitizer nor very irritating to the skin and eyes nor skin. Rimsulfuron caused some toxicity in subchronic and chronic animal feeding studies, including liver, kidney, and testicular toxicity. However, this chemical did not cause any developmental toxicity in offspring when administered to pregnant rats and rabbits during organogenesis. In a multi-generation reproductive toxicity study, reproductive effects did not occur, but decreased body weight and body weight gain in the F 1 generation was reported. Rimsulfuron did not cause oncogenic effects in rat or mouse chronic feeding studies and was negative in a number of genotoxicity studies. Based on these studies, the U.S. Environmental Protection Agency (U.S. EPA) classified rimsulfuron as not likely to be a human carcinogen. A current search of the toxicological literature did not find any significant new information on the toxicity of rimsulfuron. The U.S. EPA established tolerances for rimsulfuron residues in or on a number of crops (Federal Register 72 (No. 147): 41,909 41,913; August 1, 2007). The U.S. EPA derived a chronic population adjusted dose (cpad) for rimsulfuron of milligrams per kilogram body weight per day (mg/kg/day) from the no-observed-effect-level (NOEL) of 81.8 mg/kg/day in a one year dog study (increased absolute liver and kidney weights and testicular toxicity) and an uncertainty factor of 100. The U.S. EPA estimated that the chronic dietary exposure from food and drinking water to rimsulfuron residues would be less than 1 percent of the cpad for the general population and all population subgroups. This chronic exposure analysis is based on the conservative assumptions that 100 percent of the crops are treated and that these treated crops contain tolerance level residues. The U.S. EPA did not conduct an occupational risk assessment for exposure to rimsulfuron from DuPont Matrix FNV Herbicide because no dermal or inhalation toxicological endpoints were identified in the toxicity database for any exposure time period. No direct residential exposures are anticipated to occur from the labeled use of DuPont Matrix FNV Herbicide. There are no chemical specific federal or New York State drinking water/groundwater standards for rimsulfuron. Based on its chemical structure, this chemical falls under the 50 microgram per liter (µg/l) New York State drinking water standard for unspecified organic contaminants (10 NYCRR Part 5, Public Water Systems). The available information on rimsulfuron and the formulated product DuPont Matrix FNV Herbicide indicates that they are not very acutely toxic in laboratory animal studies, nor were they irritating or sensitizers. While rimsulfuron caused some adverse effects in chronic animal feeding studies, it did not cause oncogenic, teratogenic or reproductive effects. The expected direct exposure from the labeled use of the formulated product is rather low and should not pose a significant risk to the general public or to workers. Given the above, NYSDOH does not object to the registration of DuPont Matrix FNV Herbicide in the State. However, as NYSDOH staff noted in our previous review, rimsulfuron may pose a risk of groundwater/drinking water contamination and the Bureau of Pesticides Management

3 Mr. Tim McPherson 3 should consider whether mitigative measures (e.g., prohibiting its use in vulnerable areas of the State) are necessary before making a final decision on registration of this product in New York State. Ecological Effects Risk Assessment: Chemical Description: Matrix FNV Herbicide is a sulfonylurea herbicide with the active ingredient rimsulfuron that was originally registered for use on corn and potatoes. The Bureau of Habitat completed the original review of rimsulfuron in June The active ingredient rimsulfuron is applied at a single and maximum application rate of lbs AI/year (28.4 g/year). This is twice the maximum seasonal application of lbs AI/acre previously reviewed. Matrix FNV is applied as a single, broadcast, pre-emergence application to the bare ground of orchard floors where it permeates the soil and is absorbed by growing target broadleaf weeds and grasses. It can also be applied early post-emergence if the target weeds are small and actively growing. Instead of broadcast applications, Matrix FNV can also be applied directly around the base of trees in band applications. In this manner, Matrix can be applied twice annually, but the maximum application rate cannot exceed lbs rimsulfuron per acre per year. Rimsulfuron is highly soluble in water, and has a very low n-octanol water partition coefficient (K OW ), indicating that it is likely to be very mobile in soil and not bind strongly to organic carbon in the soil when applied, and is not likely to bioaccumulate in fish or other aquatic organisms. However, the disassociation constant pka of 4.0 suggests that it would be anionic in soils with a ph of over 4.0, and bind weakly to soil particles, most of which are negatively charged. Toxicity: The rimsulfuron mode of action is to inhibit acetolactate synthase (also known as acetohydroxyacid synthase, AHAS), a key enzyme in biosynthesis of certain amino acids in plants. As this enzyme occurs in plants, rimsulfuron has little toxic impact on mammals, birds, fish, or aquatic invertebrates. Non-target plants, including aquatic plants potentially exposed through runoff or spray drift, are highly susceptible to rimsulfuron toxicity. The most sensitive aquatic plant tested was duckweed (Lemna gibba), with a 14 day EC50 of mg/l and a corresponding no effects concentration (NOEC) of mg/l. Exposure: Rimsulfuron breaks down rapidly when applied to soil. Four terrestrial field dissipation studies showed half-lives to range from T 1/2 = 5-18 days with a geometric mean of 9 days. The primary route of degradation appears to be aerobic metabolism. In water, the primary route of degradation appears to be hydrolysis, with the rate being somewhat dependent upon ph: T 1/2 = 4.5 to C, ph 5 T 1/2 = 7.1 to C, ph 7 T 1/2 = 4.2 to C, ph 9 One of the major degradation products of rimsulfuron is IN (N-((3-Ethylsulfonyl)-2- pyridinyl)-4,6-dimethoxy-2-pyrimidineamine). This degradation product is persistent, showing no decline in a one year aerobic soil metabolism study. In a study of rimsulfuron degradation in mixed

4 Mr. Tim McPherson 4 sediment/water systems, IN reached a maximum concentration of 98% then declined to 65% by the end of the six month study. Although this was an aerobic metabolism study, it is possible that the biodegradation of IN was enhanced by photolysis. There is no indication that IN exhibits any toxicological properties, but the U.S. EPA has required aquatic fish early life stage (ELS) and invertebrate life cycle studies of this metabolite. Risk Assessment Modeling: Rimsulfuron clearly poses no risks to birds, mammals, fish, or aquatic invertebrates. The mode of toxicity is applicable only to plant physiology, the residue values are all well below toxicity thresholds, and rimsulfuron is generally applied to bare ground to prevent weeds (pre-emergence), and not to foliage that birds, mammals, and other varieties of organisms would feed upon. PONDTOX modeling was conducted to evaluate the risks to aquatic plants via runoff. Because of the low K OW of rimsulfuron, the model selected runoff rates of 1%, 3%, and 5% to evaluate. No allowance was made for foliar application, as rimsulfuron is applied to bare ground. At the highest runoff rate evaluated, 5%, the risk quotient (i.e., concentration risk threshold ) for the no observed effects concentration (NOEC) was exceeded. RQ Values were 69.7 for a one foot deep pond, 33.3 for a 3 foot deep pond, and 18.7 for a 3 foot deep pond. At the lowest runoff rate of 1%, the RQs diminish to 13.9, 6.7, and 3.7 in one, three, and six foot deep ponds, respectively. EC50s were not exceeded at either runoff rate. The next most sensitive representative aquatic plant green algae (Selenastrum capricornutum) was not affected by rimsulfuron. Risk Analysis: Risk assessment modeling of rimsulfuron suggests that this active has the potential to be harmful to aquatic macrophytes. However, the macrophyte test was a 14 day exposure. At neutral ph, rimsulfuron degrades via hydrolysis with a half life of about 7 days. At higher or lower ph values, hydrolysis is even faster. The effect of rimsulfuron evaluated in the aquatic macrophyte test was growth, not survival. Thus, it is possible that some sensitive aquatic plants might experience a short period of reduction in growth from a sizeable runoff event, but such an impact is not likely to cause significant harm to aquatic macrophytes. Other Ecotoxicology Issues: The Bureau of Habitat is becoming increasingly concerned about the application of persistent materials and the evolution of persistent degradates to the landscape, even if they do not appear to be toxic. The long term effect of these extremely persistent molecules to ecological resources is unknown. Rimsulfuron degrades into one such persistent degradate, IN The U.S. EPA has required additional toxicity testing for this material. The Bureau of Habitat would like to receive copies of these studies as soon as they are submitted to the U.S. EPA so as to be aware of any potential problems that could result from the use of rimsulfuron.

5 Mr. Tim McPherson 5 Environmental Fate Risk Assessment: Solubility: The solubility of rimsulfuron is 7.3 ppm. Hydrolysis: MRID In a study that the U.S. EPA found acceptable, the average calculated half-lives in ph 5, 7, and 9 buffer solutions were 4.6 days, 7.2 days and 7.6 hours, respectively. Aqueous Photolysis: MRID In a study that the U.S. EPA found acceptable, the half-lives in ph 5, 7, and 9 buffer solutions for the pyridine label were 1.1 days, 12.4 days and 12 hours, respectively. In the pyrimidine labeled ring half-lives in ph 5, 7, and 9 buffer solutions for the pyridine label were 1.1 days, 11.0 days and 10.2 hours, respectively. Soil Photolysis: MRID In a study that the U.S. EPA found acceptable, in a sandy loam soil (ph 6.7, 1.1% OM), the half-lives ranged from days. No major transformation products were found. Aerobic Aquatic Metabolism: MRID In a study that the U.S. EPA found acceptable, in a sandy loam soil (ph 6.7, 1.1% OM), the observed and calculated half-lives were 10 and 21.3 days, respectively. Major transformation product IN was found at 41.3% and IN-E9260 was found at 15.6% of applied. Anaerobic Soil Metabolism: MRID In a study that the U.S. EPA found supplemental, the calculated half-lives were 18.1 and 17.9 days in the pyridine and pyrimidine labels, respectively. Major transformation product IN was found at 23.1% and 33.9% in pyridine and pyrimidine labels, respectively. Anaerobic Aquatic Metabolism: MRID In a study that the U.S. EPA found ancillary, half-lives were less than 2 days and 1 day, respectively, in the non-sterile and sterile samples. Aerobic Soil Metabolism: According to the March 14, 2007 U.S. EPA Environmental Fate and Effects Division (EFED) Section 3 Registration memo, the half-lives range from days for one soil, and 5-18 days in another study under field conditions. However, the U.S. EPA requested that the registrant submit another aerobic metabolism study for this active ingredient. DuPont indicated that they will be submitting this study to the U.S. EPA, and indicated that the study had half-life values ranging from 5-40 days. DuPont referenced another study entitled Aerobic Soil metabolism of [Pyridine-2-14 C]DPX- E9636 and [Pyrimidine-2-14 C]DPX-E9636 dated September 13, 1989 (Naidu, M. V.). That study indicated that the half-life of the parent is 10 days, and that IN was found at a maximum of 20%, IN was found at a maximum of 54%, and E9260 was found at a maximum of 16%.

6 Mr. Tim McPherson 6 Aerobic Soil Metabolism Degradates: Soil Type %OM ph T ½ IN-J0290 T ½ IN T ½ IN Sandy loam Sandy loam Clay soil Sandy loam Loamy sand Sandy loam Silt loam T ½ E9623 Adsorption/Desorption: MRID In a study which DuPont indicated that the U.S. EPA accepted (via memo dated May 19, 1992 from A. Abramovitch to R. Taylor/V. Walters): Soil Type %OM ph Sandy loam Sandy loam Clay loam Silt loam Freundlich adsorption Kd According to the March 14, 2007 EFED Section 3 Registration memo, the Kocs range from Adsorption/Desorption Degradates: Soil Type %OM ph Koc IN- J0290 Koc IN Koc IN Koc E9623 Sandy loam Sandy loam Clay soil Sandy loam Loamy sand Loamy sand Silt loam Sandy loam Silt loam Column Leaching: MRID In a study that provides additional information: Soil Type Mobility %OM ph Sandy loam Mobile Sandy loam Very mobile Clay loam Medium mobility Silt loam Medium mobility

7 Mr. Tim McPherson 7 Terestrial Field Dissipation: MRID No review conclusions could be made from a study that the U.S. EPA determined had multiple deficiencies. DuPont provided a copy of their response to the U.S. EPA. MRID From a study that the U.S. EPA found unacceptable, the registrant indicated that half-lives were 5.4 days and 5.9 days in a silt loam soil (ph 6.0, 1.4% OM) in the pyridine and pyrimidine labels, respectively. In DuPont s response to the U.S. EPA, they indicated that the half-life in a clay loam soil (ph 7.0, %OM 1.3) was days, in a silty clay loam soil (ph 7.7, %OM 1.2) was days, in a clay soil soil (ph 17.4, %OM 4.5) was days, and in a sandy loam soil (ph 6.7, %OM 1.1) was days. Lysimeter Study: According to DuPont, the U.S. EPA did not review the lysimeter study submitted in The soil was a silt loam (ph , % OM). The study indicates that rimsulfuron was not observed in the leachate from any lysimeter at any time during the study. Transformation products were not part of the analyses. Computer Modeling: Name Koc T ½ Application rate Leaching Rimsulfuron Peaks to 0.38 Rimsulfuron Peaks to 1.1 Rimsulfuron Peaks to 0.21 Rimsulfuron Peaks to IN (54%) Cyclic peaks 3 to 7 ppb IN (20%) Accumulation up to E (16%) Cyclic peaks 2.5 to ~3.5 Environmental Fate Summary: This active ingredient is currently registered for use on potatoes, tomatoes and field corn. Given the large acreage of field corn in New York State, the use of this product as a selective broadleaf herbicide on pome and stone fruit, grapes and tree nuts will probably not have a significant negative impact on groundwater. However, the additional non-crop uses are a concern; the model projected that degradate IN will leach consistently into groundwater and the non-crop sites tend to have more bare ground than the pome and stone fruit, grapes and tree nut sites. Therefore, Engineering Geology staff have no objection from a groundwater perspective to the addition of pome and stone fruit, grapes and tree nuts, but object to the addition of non-crop sites. Summary: The environmental fate technical review indicated a concern regarding the leaching characteristics of the major degradate IN As such, the Department objected to the non-crop application sites due to the fact that these sites tend to have lower interception rates than agricultural sites. The Department s position regarding the use of Matrix FNV Herbicide on non-crop sites was communicated to DuPont on May 8, To facilitate registration of the agricultural uses, DuPont requested that the application for non-crop use be withdrawn. Therefore, the Department has registered DuPont Matrix FNV Herbicide (EPA Reg. No ) for the additional use sites of citrus fruit, stone fruit, pome fruit,

8 Mr. Tim McPherson 8 grape, and tree nuts. In addition, DuPont s written request to withdraw the application for non-crop uses of Matrix FNV Herbicide has been granted. Any future application for non-crop uses of rimsulfuron, or any other application containing rimsulfuron that is likely to increase the potential for significant impact on humans, non-target organisms, or the environment, would constitute a major change in labeled use pattern. Such an application must be accompanied by a new fee and meet the application requirements specified in 6 NYCRR Part Please contact Shaun Peterson, of my staff, at (518) if you have any questions regarding this letter. Sincerely, Maureen P. Serafini Maureen P. Serafini Director Bureau of Pesticides Management