Azoxystrobin - Major Change in Labeling for Heritage, Abound, and Quadris 4/00

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Azoxystrobin - Major Changes in Labeling 4/00

Azoxystrobin - Registrations of Major Change in Labeling (MCL) for Heritage Fungicide (EPA Reg. No. 10182-408) and Revised Labeling for Abound Flowable Fungicide (EPA Reg. No. 10182-415) and Quadris Flowable Fungicide (EPA Reg. No. 10182-415) 4/00

New York State Department of Environmental Conservation
Division of Solid & Hazardous Materials
50 Wolf Road, Albany, New York 12233-7254
Phone: (518) 457-6934 FAX: (518) 457-0629

April 11, 2000

CERTIFIED MAIL
RETURN RECEIPT REQUESTED

Thomas L. Woods, Ph.D.
Regulatory Product Manager
Zeneca Ag Products
PO Box 15458
Wilmington, DE 19850-5458

Dear Dr. Woods:

Re: Registration of a Major Change in Labeling for the Active Ingredient Azoxystrobin, Contained in the Pesticide Product Heritage Fungicide (EPA Reg. No. 10182-408); Acceptance of Revised Labeling for Abound Flowable Fungicide (EPA Reg. No. 10182-415) and Quadris Flowable Fungicide (EPA Reg. No. 10182-415)

The Department has completed its review of your application, received February 12, 1999, to register the above-mentioned product in New York State. Heritage Fungicide contains the active ingredient azoxystrobin and is currently registered for use on turf. The new Heritage Fungicide label adds the use of the product on ornamentals. The proposed use of Heritage Fungicide on ornamentals represents a major new use pattern for the active ingredient azoxystrobin in New York State.

Heritage Fungicide is a broad-spectrum fungicide applied as a foliar spray on turf which controls plant pathogens from all four major fungal groups: ascomycetes, basidiomycetes, deuteromycetes, and phycomycetes. It is recommended for control of certain pathogens causing foliar, aerial, and root diseases, including leaf, tip, and flower blights, leaf spots, downy mildew, powdery mildew, anthracnose, and rusts of ornamental plants. Heritage Fungicide is labeled for use on container, bench, flat, bed or field-grown ornamentals in greenhouses, shade-houses, outdoor nurseries, and other landscape areas. The United States Environmental Protection Agency (USEPA) categorized azoxystrobin as a reduced-risk pesticide.

The Heritage Fungicide major change in labeling application was deemed complete on April 5, 1999 and a registration decision, according to legislatively mandated time frames, was due by September 2, 1999. However, the Department, in the Abound Flowable Fungicide registration letter dated March 27, 1998, stated that no expanded uses for azoxystrobin on Long Island would be approved unless a groundwater monitoring program was developed by the registrant, Zeneca Ag Products. This statement would apply to all products submitted for registration in New York State and includes products to be registered in conjunction with a Supplemental Distributor.

Zeneca Ag Products waived the registration decision date for the major change in labeling application for Heritage Fungicide (EPA Reg. No. 10182-408) until the time when a mutually agreeable groundwater monitoring program was implemented for azoxystrobin.

The Department has reviewed all of the information submitted to date in support of the registration of azoxystrobin containing products. Our groundwater staff stated that the aerobic soil metabolism studies indicated a half-life ranging from 54-164 days. The photolysis half-life was 11 days. During the field studies, azoxystrobin had a half-life of 3-20 days, with only photolytic degradates detected in the dissipation studies. The Koc of azoxystrobin, in a soil with a pH of 5.5, ranged from 520 to 1600, and field studies, in a variety of agronomic conditions and in turf, have confirmed that the parent had moderate to low mobility in soil. Compound 2 the major photolytic degradate, had a Koc of 28-490 in soil with a pH of 5.5, making it mobile to fairly mobile. The inerts would not be expected to be solvent carriers. The data indicated that photolysis and microbial activity are major routes of degradation of azoxystrobin. Azoxystrobin has several degradation products, with Compound 2, Compound 28 and Compound 30 being discussed the most by USEPA's Environmental Fate and Ground Water Branch (EFGWB).

EFGWB issued a memorandum entitled "Review of Environmental Fate Data to Support the Registration of Azoxystrobin (ICIA5504) Use on Grapes and Turf" dated 8/1/96. In that memorandum, the USEPA expressed concern regarding the similarity of azoxystrobin and its degradates with other chemicals that have a tendency to leach and cause an impact to groundwater. The USEPA was concerned that the active ingredient will reach the soil via overspray or foliar wash-off, or soil incorporation into sandy soils. The three degradates, especially Compound 2, exhibited high mobility and some persistence in laboratory and field studies, leading to the concern for impact to ground and surface waters. Zeneca's rebuttals consistently stated that the groundwater statement is not fully justified based on available data. However, the USEPA and Zeneca agreed to include the following groundwater advisory on the labeling for azoxystrobin products:

"The active ingredient, azoxystrobin, in this product can be persistent for several months or longer. Azoxystrobin has degradation products which have properties similar to chemicals which are known to leach through soil to ground water under certain conditions as a result of agricultural use. Use of this chemical in areas where soils are permeable, particularly where the water table is shallow, may result in groundwater contamination."

The Department has stated that a groundwater monitoring program would be required in order to allow the use of additional azoxystrobin containing products on Long Island. Azoxystrobin has been registered statewide for use on turf as Heritage Fungicide. The turf use rate is higher than the rates for use on the Abound and Quadris labels. However, azoxystrobin is taken up by foliage rapidly and degrades via photosynthesis, and therefore, the higher rate on turf is not of concern. Additionally, fungicides typically are spot applied rather than broadcast on turf. The Department is concerned about drift to bare soil which is likely to occur when azoxystrobin is used on crops which are planted so that there would be bare ground sheltered from direct sunlight between the rows. Our groundwater staff is also concerned regarding the cumulative usage of azoxystrobin on different crops on Long Island. The concerns are heightened by the USEPA approval of azoxystrobin on several additional crops.

Compound 2 appears to be the metabolite of concern for use on Long Island. Zeneca Ag Products submitted several field dissipation studies, one of which suggested that azoxystrobin and the metabolites will not leach in acidic soils. All other data provided by Zeneca Ag Products continues to indicate that azoxystrobin and metabolites have the propensity to leach to groundwater in a vulnerable aquifer such as Long Island.

Field dissipation studies cannot replace real world monitoring data. Considering azoxystrobin exhibits a chemical profile consistent with products seen on Long Island such as DCPA, atrazine, simazine and metolachlor, technical concerns remain.

The proposed groundwater monitoring program, submitted by Zeneca Ag Products, for azoxystrobin on Long Island has been thoroughly discussed and has been found acceptable with a few minor modifications.

Zeneca Ag Products commits to the following with respect to the groundwatermonitoring program:

Monitoring program to be implemented in the year 2000 with first well samples (baseline) taken in the spring.
Monitoring program to consist of 15 wells covering three crop groupings (food crops, vines, and ornamentals) with the number of wells per grouping based upon usage of azoxystrobin.
Existing Suffolk County Health Department monitoring wells will be sampled, providing they meet relevant selection criteria for acceptability. Sampling of wells to be undertaken by the Suffolk County Health Department or independent third party.
Wells sampled semi-annually (spring and fall) for a period of at least three years (2000, 2001, 2002). The sampling program will be re-evaluated at the end of the three-year period. Termination of the monitoring program will be dependent upon review of the usage records, weather data and analytical results. Continuation of the New York State registration for all azoxystrobin products will be dependent upon the monitoring results. The Department may require the continuation of the monitoring program and additional samples to be collected for presence of azoxystrobin and the metabolites.
Samples will be analyzed by Zeneca Ag Products for parent azoxystrobin and the soil degradate Compound 2.
Zeneca Ag Products to supply the Department with a complete updated Quality Assurance Plan and list of cooperators within 30 calendar days of receipt of this letter. Also, Zeneca Ag Products must submit, at the end of each growing season, a list of grower cooperators and azoxystrobin usage records.
Zeneca Ag Products to submit, as Confidential Business Information, annual Long Island sales records for all products which contain azoxystrobin.
The Department also requests that two weeks notice of sampling events is given in order to allow the Department a chance to observe sampling procedures and techniques.

Management of pesticides on Long Island allows the products to be used under normal use conditions while conducting groundwater monitoring, which includes all current use patterns, for very early detection. If and when products are identified in groundwater samples, a proposal to cut back usage on Long Island is suggested. Because the agricultural use of azoxystrobin is obviously so important to the growers on Long Island, the Department suggests that Zeneca Ag Products carefully examine the possible future direction of azoxystrobin use in New York State before additional uses are sought for Long Island. Expanding the use of azoxystrobin to the homeowner market would add a potential source of groundwater contamination which may jeopardize all uses, including agricultural, on Long Island if azoxystrobin and/or metabolite(s) are detected in groundwater samples. Should Zeneca Ag Products decide to expand the use of azoxystrobin to the homeowner market, the groundwater monitoring program, which includes all use patterns currently registered in New York State, would have to be amended to add homeowner use.

There are no chemical-specific federal or State drinking water/groundwater standards for azoxystrobin or its degradates. Based on the chemical structure of azoxystrobin and the degradates, most often referred to in the environmental fate data (compounds 2, 9, 28 and 30), these compounds fall under the 50 micrograms per liter (μg/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 μg/L.

The proposed New York State drinking water/groundwater standard for azoxystrobin and each of the degradates is 50 μg/L, or 50 parts per billion (ppb). The proposed drinking water/groundwater standard for the sum of azoxystrobin and all degradates is 100 ppb. The trigger level for removal of all uses of azoxystrobin on Long Island would be half of the drinking water/groundwater standard or 25 ppb for azoxystrobin, 25 ppb for each metabolite and 50 ppb for the sum of the total metabolites.

Data collected will be compared to guidance values of half of the trigger level for removal of azoxystrobin use on Long Island. The guidance values are 12.5 ppb for azoxystrobin, 12.5 ppb for each metabolite and 25 ppb for the sum of the total metabolites. The trigger points for action concerning the use of azoxystrobin products on Long Island will include confirmed, increasing analytical results which approach, not exceed, these guidance values; several confirmed scattered data points which approach, not exceed, these values and persist; or a single confirmed area of high concentration which approaches or exceeds these guidance values. Analytical results will be confirmed through resampling of the data point and evaluation of its well site. However, a single exceedence, which is the result of a confirmed spill or other similar contamination, will not be considered a trigger point. Once a trigger point analysis is confirmed, Zeneca Ag Products will take steps to decrease the amount of azoxystrobin used in Nassau and Suffolk Counties in New York State.

Therefore, the Department hereby accepts for general use registration in New York State the major change in labeling for Heritage Fungicide (EPA Reg. No. 10182-408). Also, the Department accepts the revised labels, based on the most current EPA accepted label dated December 15, 1999, for Abound Flowable Fungicide (EPA Reg. No. 10182-415) and Quadris Flowable Fungicide (EPA Reg. No. 10182-415). The Abound and Quadris labels bear label code #010003 and allows the use of the products in Nassau and Suffolk Counties. The continued use of the above-mentioned products, and any other azoxystrobin product or products, in Nassau and Suffolk Counties, New York, is contingent upon the adherence to the outlined groundwater monitoring program for azoxystrobin.

Enclosed are your New York State Certificate of Pesticide Registration andNew York State stamped 'ACCEPTED' labels.

If you have any questions, please contact Maureen P. Serafini, Chief of our Pesticide Product Registration Section, at (518) 457-7446.

Sincerely,

Stephen Hammond, P.E.
Director
Division of Solid & Hazardous Materials

Enclosures

cc: w/enc. - N. Kim/D. Luttinger - NYS Dept. of Health
J. Leach/J. Kaplan - NYS Dept. of Health
R. Zimmerman/ R. Mungari - NYS Dept. of Ag. & Markets
G. Good/W. Smith - Cornell University, PMEP

JMB:scy
(AZOXY_HM.REG)
Dr. Thomas L. Woods

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