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
Division of Solid & Hazardous Materials
50 Wolf Road, Albany, New York 12233-7254 Phone: (518) 457-6934 FAX: (518) 457-0629
April 11, 2000
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
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
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
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
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.
Stephen Hammond, P.E.
Division of Solid & Hazardous Materials
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