flutolanil (Moncoat) NYS DEC Letter - Registration of a Major Label Change 12/02
flutolanil (Moncoat) NYS DEC Letter - Registration of a Major Label Change 12/02
New York State Department of Environmental Conservation
Division of Solid and Hazardous Materials
Bureau of Pesticides Management, 9th Floor
625 Broadway, Albany, New York 12233-7254
Phone: (518) 402-8788 FAX: (518) 402-9024
December 19, 2002
RETURN RECEIPT REQUESTED
Ms. Marie A. Maks
Manager, Regulatory Affairs
Nichino America, Inc.
4550 New Linden Hill Road, Suite 501
Wilmington, Delaware 19808
Dear Ms. Maks:
Re: Registration of a Major Change in Labeled (MCL) Use Pattern for Flutolanil Contained in the Pesticide Product MonCoat MZTM Potato Seed-Piece Treatment (EPA Reg. No. 71711-8)
The New York State Department of Environmental Conservation (Department) has completed review of the application (received 01/08/02) and supplemental information supplied to date regarding registration of the referenced pesticide product in New York State.
MonCoat MZTM Potato Seed-Piece Treatment (EPA Reg. No. 71711-8) contains 1.5% flutolanil and 6.0% mancozeb and is labeled for application to potato seed pieces for the suppression of seed borne Fusarium dry rot, Black scurf, Silver scurf, and Rhizoctonia stem canker. Product is applied at the rate of 0.75 to 1.0 lb. of product per 100 lb. of cut seed. The proposal to register a pesticide product labeled for food crop use represents a major change in labeled (MCL) use pattern for flutolanil in New York State. The coformulated active ingredient, mancozeb, is a component of a number of currently registered pesticide products labeled for application to potato seed pieces.
The application package was deemed complete for purposes of technical review on
June 6, 2002 following one determination of incompleteness (02/28/2002). However, Nichino America, Inc. (Nichino) was notified that failure to address the deficiencies in the water and soil residue methods may result in an unfavorable registration decision. Pursuant to the review time frame specified in Environmental Conservation Law (ECL) §33-0704.2, a registration decision date of November 3, 2002 was established.
By mutual agreement, the registration decision date was subsequently waived in order to accommodate the review of additional information submitted by Nichino in response to deficiencies noted (10/23/02) in the water and soil residue methods. Upon review of the information submitted by Nichino on October 31, 2002, the soil and water residue methods were determined to be acceptable on December 16, 2002.
The Department conducted toxicological, ecological effects and environmental fate risk assessments for flutolanil and the MonCoat MZTM formulated product.
TOXICOLOGICAL RISK ASSESSMENT:
On an acute basis, the MonCoat MZTM formulated product was not very toxic to laboratory animals by the oral, dermal or inhalation routes of exposure. It also was neither very irritating to rabbit skin or eyes nor did it cause dermal sensitization (tested on guinea pigs).
Previous reviews of flutolanil as a component of the pesticide products Prostar 50 WP, Prostar 70 WP Fungicide and Contrast 70 WPS Fungicide indicated that flutolanil was not very acutely toxic in laboratory animal studies, did not cause oncogenic effects and was generally negative in genotoxicity studies (flutolanil was positive in an in vitro chromosomal aberration assay in Chinese hamster lung cells). In addition, the reproductive/developmental toxicity studies in rats and rabbits indicate that flutolanil caused neither parental toxicity nor adverse reproductive/developmental effects.
The United States Environmental Protection Agency (USEPA) Office of Pesticide Programs had established (Federal Register: August 7, 1998, Volume 63, Number 152, pages 42249 - 42257) a reference dose (RfD) for flutolanil of 0.63 milligrams per kilogram body weight per day (mg/kg/day) based on a no-observed-effect level (NOEL) of 63 mg/kg/day in a multi-generation reproduction study in rats and an uncertainty factor of 100. Since that time, the USEPA has classified this study as "unacceptable" due to a number of study deficiencies including inadequate histopathological data and uncertainties in the accuracy of the doses of flutolanil that were administered to the animals in this study. Subsequently, the USEPA established a revised RfD of 0.87 mg/kg/day based on a NOEL of 87 mg/kg/day from a chronic feeding/oncogenicity study in rats (decreases in body weight and body weight gain and increases in absolute and relative liver weights) and an uncertainty factor of 100. This RfD has not yet been adopted by the USEPA's Integrated Risk Information System (IRIS) which in 1989 adopted an RfD of 0.06 mg/kg/day based on the above discussed multi-generation reproduction study and an uncertainty factor of 1,000 (at that time, USEPA used an additional uncertainty factor of ten to account for the determination that a NOEL was not identified in the study). A current search of the toxicological literature did not yield any significant new information on the toxicity of flutolanil.
The USEPA established a tolerance for flutolanil residues in or on potatoes at 0.2 parts per million. The USEPA estimated that chronic dietary exposure to these residues would be less than 1.0 percent of the chronic population adjusted dose (cPAD) of 0.87 mg/kg/day for both the general United States population and infants less than one-year old. This chronic exposure analysis is based on the assumption that 100 percent of the potato crops are treated and contain tolerance level residues.
The USEPA reported the results of a risk assessment for inhalation exposure (a dermal risk assessment was not required) of workers to flutolanil. For commercial mixer/loader/applicators, a margin of exposure (MOE) was estimated to be 180 and was based on a worker treating 75,000 pounds of potato seed pieces per day using 0.015 pounds of flutolanil per 100 pounds of seed pieces (the maximum labeled application rate). The NOEL used in estimating this MOE was 87 mg/kg/day from a chronic rat toxicity study. Generally, the USEPA considers MOEs of 100-fold or greater to provide adequate worker protection.
There are no chemical specific federal or State drinking water/groundwater standards for flutolanil. Based on its chemical structure, flutolanil falls under the 50 microgram per liter general New York State drinking water standard for an "unspecified organic contaminant" (10 NYCRR Part 5, Public Water Systems).
The available information on flutolanil and the formulated product MonCoat MZTM Potato Seed-Piece Treatment indicates that they were not very acutely toxic in laboratory animal studies. Flutolanil also was not very toxic in chronic feeding studies and did not cause any oncogenic or teratogenic effects. In addition, the estimated risks posed by flutolanil to workers and the general public from use of this product are within the range considered acceptable by the USEPA.
ECOLOGICAL EFFECTS RISK ASSESSMENT:
MonCoat MZTM Potato Seed-Piece Treatment contains the two previously registered active ingredients flutolanil and mancozeb at 1.5% and 6.0%, respectively. It is the first use of flutolanil on a food crop. Mancozeb is a component of a number of currently registered fungicidal products, including potato seed-piece treatments, but has not previously been reviewed for non-target organism impacts. The MonCoat MZTM data package contains no physical/chemical, toxicity, or environmental fate data for mancozeb. However, a second product containing mancozeb is currently in the review queue and its data package includes an overview document that provides summaries of over 200 mancozeb and metabolite, mammalian toxicological, biokinetics, and human epidemiological studies. Unfortunately, only NOEC values are reported which somewhat limits the utility of the document. Five additional references provided the basic ecotoxicology, chemical, and environmental fate data needed to assess the potential for MonCoat MZTM use to result in adverse non-target organisms effects.
USE PATTERN: MonCoat MZTM is applied to freshly cut potato seed pieces pre-planting to protect against Black scurf, silver scurf, Fusarium dry rot and Rhizoctonia stem canker. It is applied at a rate of 1 pound MonCoat MZTM per 100 pounds of seed. A typical potato seed planting rate of 1700 to 2000 pounds per acre results in a maximum application rate of 0.3 lbs. flutolanil and 1.2 lbs. mancozeb per acre.
CHEMICAL DESCRIPTION: Flutolanil's chemical characteristics were summarized in a 1995 review of ProStar 50WP turf fungicide containing 50% flutolanil as the active ingredient.
Mancozeb [[1,2-ethanediylbis-[carbamodithioato]](2-)] manganese, mixture with[[1,2-ethanediylbis-[carbamodithioato]]-(2-)]zinc is an ethylene bisdithiocarbamate (EBDC) fungicide. Different sources report water solubilities ranging from 6 mg/L to 20 mg/L at 25O C. With a vapor pressure of 7.6x10-6 mmHg, volatilization is not likely to contribute to its dissipation. It's octanol/water partitioning coefficient (KOW) is 21.8 which is indicative of low potential for bioaccumulation and high soil mobility.
TOXICITY & ENVIRONMENTAL FATE: Although it is persistent, flutolanil is practically non-toxic to birds and mammals on both an acute and chronic basis and presents no risk to them when used at seasonal rates up to 8.2 lbs. ai/acre. Mancozeb is also practically non-toxic to birds and mammals on an acute basis but can be chronically toxic to mammals. No mancozeb avian chronic or reproductive toxicity data was submitted or located by the reviewer.
Mancozeb is slightly more toxic to aquatic organisms than flutolanil. It is highly toxic to most test species, whereas flutolanil is moderately toxic. Both flutolanil and mancozeb are highly to very highly toxic to the representative marine/estuarine invertebrate test organism Mysid shrimp.
Mancozeb degrades rapidly in the environment via multiple pathways. It's environmental and in vivo metabolite of greatest toxicological concern is ethylene thiourea (ETU) which also degrades rapidly. Mancozeb undergoes hydrolysis with a half-life (T1/2) of 1 to 1.5 days. It's aqueous
photolysis T1/2 is less than three hours. It's aerobic and anaerobic soil T1/2's are reported as less than two days, and less than eight days, respectively. Mancozeb terrestrial field dissipation T1/2's range from one to seven days. ETU degradation rates via the various pathways are virtually identical to mancozeb's, with the exception that ETU is stable to hydrolysis.
Significant bird or mammal exposure is not likely from this use pattern, thus no feeding exposures were modeled. Coarse screening level aquatic exposures resulting from runoff were modeled utilizing highly conservative worst-case assumptions. Since mancozeb is the more toxic of the two active ingredients to aquatic organisms and the mancozeb content is four times that of flutolanil, the PONDTOX exposure estimates were based on mancozeb residues only. For the initial series of PONDTOX runs it was assumed that the maximum MonCoat MZTM application rate was applied to the surface of bare soil and that all runoff water, generated immediately after application, would reach the model pond.
The USEPA has required confirmatory formulation aquatic toxicity tests, as a condition of MonCoat MZTM registration, to establish whether there is any synergistic interaction between the two active ingredients. An additional series of PONDTOX runs was conducted over a range of exaggerated toxicity levels to estimate the magnitude of synergistic toxicity increase necessary to adversely impact non-target organisms under the conservative assumptions given above.
Fish and wildlife resources are unlikely to be adversely impacted by labeled use of MonCoat MZTM. Using standard toxicity values and 5% of the active ingredient dissolved in runoff water, only the Mysid shrimp LC50 in the one-foot water depth was reached. The NOEC for mosquitofish, rainbow trout, daphnia, and an algae were slightly exceeded in shallower depths but any mancozeb reaching the pond would quickly degrade making adverse effects unlikely. To achieve LC50 concentrations for organisms other than Mysid shrimp a 10-fold synergistic increase in toxicity and a 3% runoff rate is necessary. A toxicity increase of that magnitude is highly unlikely. Modeling assumptions more representative of actual field use conditions, particularly with respect to the fact that MonCoat MZTM is buried beneath the soil surface when used, would reduce the already minimal impacts predicted under the exaggerated conditions used in these screening exercises.
ENVIRONMENTAL FATE RISK ASSESSMENT:
MonCoat MZTM contains 1.5% flutolanil and 6.0% mancozeb and is formulated as a wettable powder that is applied to the surface of cut potato pieces at a rate of 0.75 to 1.00 lb. product per 100 lbs. of seed potatoes. This is equivalent to 0.01125 to 0.015 lb. flutolanil per 100 lbs. of seed potatoes. According to a Cornell Crop Profile, "Typically 1000-3000 lbs. of seed potatoes are planted per acre, depending on seed piece size, row spacing, and spacing between plants." Therefore, the maximum application rate for flutolanil ranges from 0.15 to 0.45 lb./acre.
Hydrolysis: Flutolanil is stable at pHs five, seven and nine.
Aqueous Photolysis: Flutolanil degraded slowly, 8% over the 30-day study. No half-life was indicated.
Soil Photolysis: This study was found unacceptable, and no useful data was presented.
Aerobic Soil Metabolism: Flutolanil had a half-life in sandy loam of 300 days.
Anaerobic Aquatic Metabolism: Flutolanil had a half-life of >13 years.
Adsorption/Desorption: Flutolanil had adsorption Kocs of 571 in sand (0.17 % organic carbon), 594 in loam, 457 in clay loam #90, 628 in clay loam #86, and 1005 in loamy sand (1.57 % organic carbon). Flutolanil had desorption Kocs of 1600 in sand (0.17 % organic carbon), 830 in loam, 669 in clay loam #90, 892 in clay loam #86, and 1327 in loamy sand (1.57 % organic carbon). Adsorption and desorption are well correlated to organic carbon content as well as pH; Kocs increase with decreasing pH.
Computer modeling: The Department's groundwater model (LEACHM) on Riverhead soil, using the maximum application rate of 0.45 lb. flutolanil/acre/planting, a Koc of 571, and an aerobic half-life of 300 days projected accumulation of flutolanil reaching a maximum of <1 ppb at approximately three years into the ten year modeling cycle.
Although flutolanil is very persistent and moderately mobile, the low application rate and method per the MonCoat MZTM use pattern should mitigate the potential for flutolanil to impact groundwater resources. In addition, the mobility of flutolanil decreases with decreasing pH. Since Long Island sands tend to have slightly acidic pHs, MonCoat MZTM should not leach significantly to groundwater on sandy Long Island soils when used as labeled.
CONCLUSION: When used as labeled, the subject product should not cause unreasonable adverse effects to humans or the environment. The Department hereby accepts MonCoat MZTM Potato Seed-Piece Treatment (EPA Reg. No. 71711-8) for registration in New York State. Enclosed for your files are the Certificate of Pesticide Registration and New York State stamped-"ACCEPTED" labeling (identified as 100402 fpl; 1/08/02).
Please note that a proposal by Nichino America, Inc., or any other registrant, to
register a product containing flutolanil, 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. Such an application must be accompanied by a new application fee and meet the requirements specified in 6 NYCRR Part 326.17.
Please contact Samuel Jackling, Chief of our Pesticide Product Registration Section, at (518) 402-8768 if you have any questions.
Maureen P. Serafini
Bureau of Pesticides Management
cc: w/enc. - N. Kim/D. Luttinger, NYS Dept. of Health
R. Zimmerman/R. Mungari, NYS Dept. of Ag. & Markets
G. Good/W. Smith, Cornell University, PMEP