indoxacarb (Avaunt) NYSDEC Registration Letter 3/02
indoxacarb (Avaunt) NYSDEC Registration Letter 3/02
New York State Department of Environmental Conservation
Division of Solid & Hazardous Materials
Bureau of Pesticides Management
Pesticide Product Registration Section
625 Broadway, Albany, New York 12233-7257
Phone 518-402-8768 FAX 518-402-9024
Website:
http://www.dec.state.ny.us/website/dshm
E-Mail: ppr@gw.dec.state.ny.us
March 21, 2002
CERTIFIED MAIL
RETURN RECEIPT REQUESTED
Ms. Miriam Carr
States Registration
E.I. du Pont de Nemours and Company, Inc.
DuPont Crop Protection
Stine-Haskell Research Center (S300/427)
P.O. Box 30, 1090 Elkton Road
Newark, Delaware 19714-0030
Dear Ms. Carr:
Re: Registration of DuPontTM Avaunt® Insecticide (EPA Reg. No. 352-597) Containing
the New Active Ingredient Indoxacarb
The New York State Department of Environmental Conservation (Department) has
completed review of the application (received 05/04/01) and supplemental information
supplied to date regarding registration of the referenced pesticide product in New
York State. DuPontTM Avaunt® Insecticide (EPA Reg. No. 352-597) contains the new
active ingredient indoxacarb. As discussed in this letter, the acceptable Avaunt®
labeling accompanying the issuance of this registration must bear the text "Not for
use or sale in Suffolk and Nassau Counties, Long Island, New York."
On October 4, 2001, the subject application and data package were deemed complete
for purposes of technical review following one determination of incompleteness
(07/03/2001). Pursuant to the review time frame specified in Environmental
Conservation Law (ECL) §33-0704.2, a registration decision date of March 3, 2002
was established. By mutual agreement, the registration decision date was subsequently
waived in order to accommodate the preparation and review of revised labeling submitted
in response to issues identified in the environmental fate risk assessment.
Avaunt® Insecticide, containing 30% indoxacarb, is labeled for foliar spray
application to apples, broccoli, cabbage (tight headed varieties only), cauliflower,
corn (sweet), lettuce (head and leaf varieties), pears, peppers (bell and non-bell)
and tomatoes only in commercial and farm plantings for the control of certain insects.
During the technical review process, DuPont submitted amended product labeling bearing
additional crops uses, i.e., brussels sprouts, Chinese broccoli, Chinese cabbage,
Chinese mustard cabbage, eggplant, and kohlrabi. The maximum seasonal use rate on
apples and pears is 24 ounces Avaunt® (0.44 lb. indoxacarb) per acre per crop. The
remaining labeled crops have a maximum seasonal use rate of 14 ounces Avaunt®
(0.26 lb. indoxacarb) per acre per crop.
The Department conducted toxicological, ecological effects and environmental
fate risk assessments for indoxacarb and the Avaunt® formulation.
TOXICOLOGICAL RISK ASSESSMENT: Indoxacarb is a mixture of two isomers, of which
only one has insecticidal activity. Indoxacarb was originally manufactured as a 50:50
mixture of these two isomers and was denoted as DPX-JW062. Subsequent production led
to the active ingredient DPX-MP062, enriched to approximately 75:25 for the
insecticidally active isomer. This enriched mixture (also referred to as indoxacarb)
is the active ingredient in the formulated end product, Avaunt® Insecticide. In
consultation with the United States Environmental Protection Agency (USEPA), the
registrant conducted a series of "bridging" studies on DPX-MP062 to demonstrate its
toxicological equivalence to DPX-JW062. Therefore, the database to support registration
of the Avaunt® product is comprised of studies conducted on DPX-MP062 or DPX-JW062.
Neither indoxacarb nor Avaunt® Insecticide was very toxic in acute dermal or
inhalation studies in laboratory animals. Also, neither material was very irritating
to the eyes or skin (tested on rabbits). On the other hand, whereas the Avaunt®
product was not very toxic via the oral route of exposure, the active ingredient
indoxacarb was moderately toxic, particularly to female rats. In addition, the Avaunt®
product was not a dermal sensitizer (tested on guinea pigs), but the active ingredient
showed some skin sensitizing properties. Indoxacarb also showed some neurotoxicity
after acute exposures in rats. A decrease in motor activity occurred in females after
a single dose of 100 milligrams per kilogram body weight (mg/kg); the no-observed-effect
level (NOEL) was 50 mg/kg.
Indoxacarb caused some toxicity in chronic animal feeding studies. In a chronic
feeding/oncogenicity study in mice, indoxacarb caused decreased body weight, body
weight gain and clinical signs indicative of neurotoxicity (abnormal gait and head
tilt) at 14 mg/kg/day and 20 mg/kg/day for males and females, respectively; the
respective NOELs were 2.6 and 4.0 mg/kg/day. In rats chronically fed indoxacarb,
decreased body weight, body weight gain and food consumption were observed in males
at 10 mg/kg/day and in females at 3.6 mg/kg/day. Also observed in females at this
same dose were decreased hematocrit, hemoglobin and red blood cells; the NOELs for
male and female rats were 5.0 and 2.1 mg/kg/day, respectively. In dogs, decreased
hematocrit, hemoglobin, red blood cells and increased absolute and relative liver
weights were reported at 18 and 19 mg/kg/day in males and females, respectively; the
respective NOELs were 2.3 and 2.4 mg/kg/day. The USEPA, Office of Pesticide Programs
established a reference dose (RfD) of 0.02 mg/kg/day based on a NOEL of 2.1 mg/kg/day
in the chronic feeding/oncogenicity study in rats, as well as in a supporting
subchronic study in rats, and an uncertainty factor of 100. This RfD has not
yet been adopted by the USEPA's Integrated Risk Information System (IRIS).
Indoxacarb caused some developmental toxicity in the offspring of pregnant
rats and rabbits, but only at doses that also caused maternal toxicity. In one
rat developmental toxicity study, a decrease in fetal weights was observed at 4.0
mg/kg/day; the NOEL was 2.0 mg/kg/day. Maternal toxicity characterized by decreased
mean maternal body weights, body weight gains and food consumption occurred at 4.0
mg/kg/day with a NOEL of 2.0 mg/kg/day. In a second rat developmental toxicity study,
decreased numbers of live
fetuses per litter were reported at 100 mg/kg/day; the NOEL was 10 mg/kg/day. The same
dose of 100 mg/kg/day was
associated with maternal toxicity effects (increased mortality, decreased mean body weights,
body weight gain and food
consumption); the NOEL was 10 mg/kg/day. No teratogenic effects were noted in either rat
study. In rabbits, reduced
fetal body weights and reduced ossification of the sternebrae were reported at 1,000
mg/kg/day; the NOEL was 500
mg/kg/day. Maternal toxicity (slight decrease in maternal body weight gain and food
consumption) also occurred at
1,000 mg/kg/day with a NOEL of 500 mg/kg/day. In a two-generation reproduction study
in rats, no reproductive effects
were observed at the highest dose tested, which was 6.4 mg/kg/day. However, maternal
toxicity characterized by reduced
body weight gains, body weights, food consumption and increased spleen weights occurred
at a dose of 4.4 mg/kg/day; the NOEL was 1.5 mg/kg/day.
Indoxacarb did not cause oncogenic effects in either rat or mouse chronic
feeding studies. It also was
negative in a number of genotoxicity studies. The USEPA classified indoxacarb as "not
likely" to be carcinogenic to humans.
The USEPA established tolerances for indoxacarb residues in or on apples
at 1.0 part per million (ppm);
brassica (5.0 ppm); corn, sweet forage (10.0 ppm); lettuce, head (4.0 ppm); lettuce, leaf
(10.0 ppm); pears (0.2 ppm)
and fruiting vegetables (0.5 ppm). Estimated acute dietary exposures to these residues
were 33 percent of the acute
population adjusted dose (aPAD) for females 13 years and older (aPAD of 0.02 mg/kg/day)
and 10 percent or less of the
aPAD (0.12 mg/kg/day) for the general population, infants and children ages one through six
years old. These estimates
used anticipated residue levels from field trial data, processing factors (where applicable)
and 100 percent crop
treatment assumptions. The USEPA estimated that chronic dietary exposure to indoxacarb
residues would be less than 28
percent of the chronic population adjusted dose (cPAD) of 0.02 mg/kg/day for the general
U.S. population, less than 37
percent for all infants less than one-year old and 73 percent for children one to six years
old. This chronic exposure
analysis is based on the conservative assumption that 100 percent of crops are treated and
contain tolerance level residues.
The registration package contained several evaluations by the USEPA and the
registrant on dermal and
inhalation exposure of workers to indoxacarb. Application of the Avaunt® product may
occur up to four times per
growing season. For commercial handlers wearing long-sleeved shirt, long pants and gloves
(required by the label),
margins of exposures (MOEs) were estimated to range from 930 to 4,200 for dermal exposure
and from 600 to 11,000 for
inhalation exposure. These estimates are conservative in that they are based on application
to cotton fields of 476 to
1200 acres per day. Crops grown in New York State are likely to pose less exposure and
risk. Initial estimates of
post-application exposure from various activities on the labeled crops identified that hand
harvesting and/or thinning
of apples, sweet corn and tomatoes did not provide adequate MOEs at proposed labeled
use. As a result, label changes
(e.g., reduced number of allowed applications, longer pre-harvest intervals) were implemented
to mitigate these risks.
Estimated MOEs for post-application activities were then revised and range from about 100
to 925. 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 indoxacarb.
Based on its chemical structure, this compound falls under the 50 microgram per liter New
York State drinking water
standard for unspecified "organic contaminants" (10 NYCRR Part 5, Public Water Systems).
The available information on indoxacarb and Avaunt® Insecticide indicates
that overall they are not
very acutely toxic in laboratory animal studies. Indoxacarb also did not cause teratogenic,
reproductive or
carcinogenic effects. Although data from chronic and developmental toxicity studies on
indoxacarb showed that this
chemical has the potential to cause some toxicity, the expected exposure from the labeled
uses of Avaunt®
Insecticide should not pose a significant risk to workers or the general public.
ECOLOGICAL EFFECTS RISK ASSESSMENT: Exposure modeling utilizing highly
conservative screening
assumptions predicts that several aquatic and terrestrial toxicity thresholds may be exceeded
at the highest labeled
application rate and shortest re-treatment intervals. The No Observable Effect Concentration
(NOEC) threshold was
exceeded for three marine/estuarine species at the highest predicted runoff rates. In no
case, however, was a Maximum Allowable Toxicant Concentration (MATC) exceeded.
A mammalian chronic feeding Lowest Observable Effect Concentration (LOEC) Ms. was
exceeded at the highest
predicted vegetation residue level. Residue levels under field conditions will be lower as no
foliar precipitation
wash-off or dilution due to growth was factored into the screening modeling. Furthermore, the
most sensitive reported
end points are used for the Department's risk assessments. In this case the threshold exceeded
was for hemolytic
effects, specifically anemia. While these effects would reduce an individual animal's fitness
should they feed
exclusively on treated vegetation, lethal or reproductive effect thresholds are not reached and
population level effects are unlikely.
While individual organisms may occasionally be adversely affected, Avaunt®
Insecticide, when used as
labeled, is not likely to significantly impact fish or wildlife resources on a widespread or
population basis.
ENVIRONMENTAL FATE RISK ASSESSMENT: The available environmental fate and
expression data indicate
that indoxacarb and its degradate IN-JT333 are not likely to be persistent or mobile in the
environment. However, the
USEPA was concerned about other degradates identified in the environmental fate studies and
the complexity of their
degradation process. The FIFRA Sec. 3(c)(7)(C) conditional registration of Avaunt®
Insecticide identified certain data gaps in the environmental fate data base for indoxacarb.
In the comment letter, dated October 30, 2000, accompanying the conditional
registration of Avaunt®
Insecticide, the USEPA specified the following data requirements for additional elucidation
of the degradates:
photodegradation in water
hydrolysis
aerobic soil metabolism
anaerobic aquatic metabolism
aerobic aquatic metabolism
leaching-adsorption/desorption
terrestrial field dissipation
accumulation in fish
This information is critical in order to conduct a comprehensive assessment of
the leachability of
indoxacarb. The potential for certain degradates to adversely impact groundwater/drinking
water resources in New York
State cannot be discounted. Of particular concern are groundwater resources on Long Island,
where sandy soils and shallow depth to groundwater are common.
DISCUSSION: The Department's concern regarding the potential for
Avaunt® to adversely impact
groundwater resources in vulnerable agricultural areas in New York State was discussed
with representatives of DuPont
in a telephone conference on February 22, 2002. In order to accommodate the concerns
regarding the uncertainties
associated with the degradate(s) leaching potential, DuPont proposed the following action
items: 1) To sticker the
front panel of existing stock of Avaunt® with the text, "Not for use or sale in Suffolk
and Nassau Counties, Long
Island, New York."; and 2) Product produced after April 15, 2002 would bear the following
text under the General
Information section of the labeling: "Not for use or sale in Suffolk and Nassau Counties,
Long Island, New York."
On February 27, 2002, DuPont submitted a copy of the notification to the
USEPA, dated February 27, 2002,
regarding this labeling change together with "stickered" labeling (SL-715 103000a 10-30-00)
and proposed revised labeling (SL-820-1 022602 01-11-02) for the Department's review.
CONCLUSION: The Department hereby accepts DuPontTM Avaunt® Insecticide
(EPA Reg. No. 352-597)
for registration in New York State. Enclosed for your files are the Certificate of Pesticide
Registration and New York
State stamped "ACCEPTED" labeling (existing stock "stickered" labeling (SL-715 103000a 10-30-00)
and revised labeling (SL-820-1 022602 01-11-02).
Please note that a proposal by DuPont, or any other registrant, to register a
product containing
indoxacarb, 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 listed in Appendix 1.B. of "New York State
Pesticide Product Registration Procedures" (August 1996).
A proposal to remove the Long Island prohibition would likewise be processed
as a MCL. Such a proposal
must be accompanied by the USEPA reviews of the environmental fate data specified as a requirement
of the conditional
federal registration issued on October 30, 2000. These data requirements were further defined in
a meeting between
DuPont and USEPA's Environmental Fate and Effects Division (EFED) on September 5, 2001 and
subsequent comments (via electronic mail) by EFED on October 26, 2001.
Please contact Samuel Jackling, Chief of our Pesticide Product Registration
Section, at (518) 402-8768, if you have any questions.
Sincerely,
Maureen P. Serafini
Director
Bureau of Pesticides Management
Enclosures
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
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