 

Docket #: EPA-HQ-OPP-2009-0774 

COMPANY NOTICE OF FILING 

<EPA Registration Division contact: Sidney Jackson, (703) 305-7610>

<Interregional Research Project No. 4 (IR-4)>

<PP9E7611>

<	EPA has received a pesticide petition PP9E7611 from Interregional
Research Project No. 4 (IR-4), 500 College Road East, Suite 201W,
Princeton, NJ 08540 in cooperation with the registrant, Syngenta Crop
Protection, Inc., 410 Swing Rd., Greensboro, NC 27419 proposing,
pursuant to section 408(d) of the Federal Food, Drug, and Cosmetic Act
(FFDCA), 21 U.S.C. 346a(d), to amend 40 CFR part 180.275 by establishing
a tolerance for residues of Chlorothalonil in or on the raw agricultural
commodity low growing berries subgroup 13-07G at 0.01 parts per million
(ppm); Bushberry subgroup 13-07B at 1 ppm; onion, bulb subgroup 13-07A
at 0.5 ppm; and onion, green subgroup 13-07B at 5 ppm.  EPA has
determined that the petition contains data or information regarding the
elements set forth in section 408 (d)(2) of  FDDCA; however, EPA has not
fully evaluated the sufficiency of the submitted data at this time or
whether the data supports granting of the petition. Additional data may
be needed before EPA rules on the petition.>

<A. Residue Chemistry>

<	1. Plant metabolism. The metabolism of Chlorothalonil as well as the
nature of the residues in plants is adequately understood for purposes
of the proposed tolerance. Plant metabolism has been evaluated in five
diverse crops: Carrots, celery, lettuce, snap beans, and tomatoes, which
should serve to define the similar metabolism of Chlorothalonil in a
wide range of crops. The qualitative nature of residues in plants for
Chlorothalonil is adequately understood. The 

residue of concern is Chlorothalonil and its metabolite, 4-hydroxy-

2,5,6-trichloroisophthalonitrile (SDS-3701). Parent metabolite CGA-

64250 is the major compound found in crops.>

<	2. Analytical method. An adequate residue analytical method (gas
chromatography) is available for enforcement purposes. The method is 

listed in the Pesticide Analytical Manual (PAM) Vol. II (PAM II).>

<	3. Magnitude of residues. All samples were analyzed for residues of
Chlorothalonil and its metabolite SDS-3701 (R182281).  The limit of
quantitation (LOQ) for Chlorothalonil and SDS-3701 were 0.030 ppm.

i.  Strawberries (low growing bush berries except cranberries):  

Eight field trials were conducted for this study.  The first field trial
(Florida 05-FL01 in EPA region 3) was conducted to determine treatment
rate and pre-harvest intervals (PHIs) for the additional trials.  The
seven remaining trials were located in Florida (region 3), California
(two trials, region 10), New York (region 1), New Jersey (region 2),
Michigan (region 5), and Oregon (region 12).

Strawberries were collected from the 05-FL01 Florida treated plot at the
nearly ripe stage, from 29 days after the fifth foliar application in
TRT 06 to 62 days after the transplant dip only (TRT 07).  Strawberries
were collected from the 05-FL49 Florida and from all California trials
at the marketable stage, from 70 days after the second application (TRT
12 in 05-FL49) to 175 days after the transplant dip only (TRT 07 in 05
CA*157).  Strawberries were collected from the New York, New Jersey,
Michigan, and Oregon treated plots at the marketable stage, from 53 days
after the final application (TRT 15 in 05-NY21) to 90 days after the
dormant spray only (TRT 13 in 05 OR18).  

The results from the trials show that no residues of chlorothalonil or
SDS-3701 (R182281) were observed in any strawberry sample above the LLMV
(0.030 ppm for GC/ECD and 0.010 ppm for GC/MSD), regardless of treatment
scenario or PHI. 

ii.   Bushberry subgroup 13-07B

The existing tolerance for blueberries is being used to request a
tolerance on Crop Subgroup 13-07B; Bushberry subgroup.

iii.   Onion subgroups 3-07A and 3-07B

The existing tolerance for bulb onion is being used to request a
tolerance on Crop subgroup 3-07A; Onion, bulb subgroup and the existing
tolerance for green onion is being used to request a tolerance on Crop
subgroup 3-07B; Onion, green subgroup.

>

<B. Toxicological Profile>

	1. Acute toxicity.  An assessment of the toxic effects caused by
Chlorothalonil is discussed in Unit III.A. and Unit III.B. in the
Federal Register of 

December 3, 2008 (FR Volume 73, Number 233) (FRL-8387-9).

	2. Genotoxicty.  An assessment of the toxic effects caused by
Chlorothalonil is discussed in Unit III.A. and Unit III.B. in the
Federal Register of 

December 3, 2008 (FR Volume 73, Number 233) (FRL-8387-9).

	3. Reproductive and developmental toxicity. .  An assessment of the
toxic effects caused by Chlorothalonil is discussed in Unit III.A. and
Unit III.B. in the Federal Register of December 3, 2008 (FR Volume 73,
Number 233) (FRL-8387-9).

<	4. Subchronic toxicity. .  An assessment of the toxic effects caused
by Chlorothalonil is discussed in Unit III.A. and Unit III.B. in the
Federal Register of 

December 3, 2008 (FR Volume 73, Number 233) (FRL-8387-9).>

<	5. Chronic toxicity. .  An assessment of the toxic effects caused by
Chlorothalonil is discussed in Unit III.A. and Unit III.B. in the
Federal Register of 

December 3, 2008 (FR Volume 73, Number 233) (FRL-8387-9)>

<	6. Animal metabolism. The metabolism of chlorothalonil in the rat 

is adequately understood.>

<	7. Metabolite toxicology. The residues of concern for tolerance 

setting purposes in or on raw agricultural commodity are the parent 

compound and its metabolite, 4-hydroxy-2,5,6-trichloroisophthalonitrile 

(SDS-3701). The residue of concern in meat and milk is SDS-3701.>

<	8. Endocrine disruption. Chlorothalonil does not belong to a class 

of chemicals known or suspected of having adverse effects on the 

endocrine system. Developmental toxicity studies in rats and rabbits 

and a reproduction study in rats gave no indication that chlorothalonil 

might have any effects on endocrine function related to development and 

reproduction. The subchronic and chronic studies also showed no evidence
of a long-term effect related to the endocrine system.>

<C. Aggregate Exposure>

<	1. Dietary exposure. Tier II/III chronic aggregate and short-term
aggregate exposure evaluations were made for chlorothalonil using the
Dietary Exposure Evaluation Model software with the Food Commodity
Intake Database (DEEM-FCID™, version 2.16) from Exponent.  Empirically
derived processing factors were used for beans (snap, babyfood and
cooked, 0.05X), cabbage (0.2X), carrots (babyfood, 0.005X), cherries
(babyfood, 0.05X), cherry juice (0.075X), cocoa (0.1X), coffee (0.1X),
cranberry juice (0.25X), cucumbers (uncooked cured, 0.2X), peach
(cooked, 0.02X), peach (dried cooked, 0.14X), peach (juice, babyfood,
0.02X), peanut oil (prune, 0.5X), plum (prune, 0.33X), soybean oil
(0.04X), squash (0.001X), tomato juice (0.25X), and tomato paste/puree
(0.02X).  All other processing factors were DEEMTM Ver. 7.87 default
values.  All consumption data for these assessments was taken from the
USDA’s Continuing Survey of Food Intake by individuals (CSFII) with
the 1994-96 consumption database and the Supplemental CSFII children’s
survey (1998) consumption database.  These assessments included all
current and pending uses plus a proposed new IR 4 pre plant dip and
foliar combination use on strawberries.  Residue data for current and
pending registrations were obtained from a number of sources including
field trial data and monitoring data from the Pesticide Data Program
(PDP), FoodContam (FC), and the FDA monitoring program.  The current
tolerance definition expression for chlorothalonil includes
chlorothalonil plus the metabolite SDS3701.  Since residue values for
chlorothalonil in the PDP and other monitoring databases may not include
residues of the SDS3701 metabolite, samples that had detectable residues
of chlorothalonil were conservatively assigned a value of 10% of the
reported chlorothalonil residue for an assumed residue of SDS3701, based
upon the maximum ratio of metabolite SDS3701 to chlorothalonil in
radio-labeled plant studies (6.5%).  A proposed tolerance of 0.02 ppm
was used for the proposed use on strawberries.  Percent of crop treated
values were estimated based upon economic, pest and competitive
pressures.  Tolerance-level residues were assumed for all meat
commodities.  For milk and milk derived commodities, relevant PDP
monitoring database residue values were used.  >

<Food. 

[Acute dietary (food only) assessments were not performed, since an
endpoint of concern attributable to a single oral dose has not been
identified.

Food Chronic Exposure:  The chlorothalonil chronic dietary (food only)
risk assessment was performed for all population subgroups using a
chronic reference dose of 0.02 mg/kg-bw/day, based upon a NOAEL of 2.0
mg/kg-bw/day from a chronic rat toxicity study and an uncertainty factor
of 100X for intra- and inter-species variability; no additional FQPA
safety factor was applied.  For the purpose of the aggregate risk
assessment, exposure values were expressed in terms of margin of
exposure (MOE), calculated by dividing the 2.0 mg/kg-bw/day endpoint by
the exposure for each population subgroup.  In addition, exposures were
expressed as a percent of the chronic reference dose (%cRfD).  Chronic
dietary (food only) exposure to the U.S. population resulted in a MOE of
10,033 (1.0% of the cRfD).  The most sensitive sub-population was
children 1-2 years old, with a MOE of 6,178 (1.6% of the cRfD).  Since
the Benchmark MOE for this assessment was 100 and since EPA generally
has no concern for exposures above the benchmark or below 100% of the
reference dose, Syngenta believes that there is a reasonable certainty
that no harm will result from dietary (food) exposure to residues
arising from all current, pending, and proposed uses of chlorothalonil.

Cancer.  Chlorothalonil is listed as “likely” to be a human
carcinogen by all routes of exposure, however the SAP decision of
6/30/98 supports the use of a MOE approach. The HASPOC deliberated on
3/12/08 and supported the MOE approach.>

<Drinking water. [Estimated Drinking Water Concentrations (EDWCs) for
chlorothalonil TTR were calculated for the currently registered uses and
the proposed uses on strawberries and citrus using the Tier II Model
PE5, PRZM (Pesticide Root Zone Model) / EXAMS (Exposure Analysis
Modeling Systems), to provide surface water exposure estimates and the
Tier 1 Model, SCI-GROW (Screening Concentration In GROund Water), to
provide ground water exposure estimates.  For surface water, the
currently registered Bravo Weather Stik® use on tomatoes was the
driving crop use and provided the highest EDWCs, exceeding the proposed
new IR-4 crop uses for strawberries and citrus.  The use parameters for
chlorothalonil on tomatoes consisted of seven aerial applications of 2.1
lbs chlorothalonil / A, and this use was modeled using the PRZM Crop
Scenarios: CA, FL and PA Tomatoes.  PRZM/EXAMS modeling provided an
annual average (chronic) surface water EDWC of 72.9 ppb.  For ground
water the currently registered use, Daconil Ultrex® on golf course turf
(greens), was the driving crop use and provided higher EDWCs than the
proposed uses for strawberries and citrus.  The application parameters
for Daconil Ultrex® consisted of ten ground applications of 7.3 lbs. ai
/ A which provided an EDWC (acute and chronic) of 6.8 ppb for
chlorothalonil TTR.  Since the surface water EDWC exceeds the ground
water EDWC, the surface water value should be used for comparison
purposes and is considered protective for any ground water concentration
concerns.  

 

Acute Exposure from Drinking Water:  Acute drinking water assessments
were not performed, since an endpoint of concern attributable to a
single oral dose has not been identified.

Chronic Exposure from Drinking Water:  The chronic EDWC of 72.9 ppb
(0.0729 ppm) was used to calculate the chronic drinking water exposure
values for the U.S. Population and all population subgroups.  Chronic
drinking water exposures to the U.S. Population resulted in a MOE of
1,302 (7.7% of the cRfD).  The most sensitive sub-population was all
infants <1 year, with a MOE of 397 (25.2% of the cRfD).  Since the
Benchmark MOE for this assessment was 100 and since EPA generally has no
concern for exposures above the benchmark or below 100% of the reference
dose, Syngenta believes that there is a reasonable certainty that no
harm will result from dietary (food) exposure to residues arising from
all current, pending, and proposed uses of chlorothalonil.>

<	2. Non-dietary exposure. Chlorothalonil is a broad spectrum fungicide
that can be applied to ornamentals and non-residential turfgrass and can
also be formulated into paints for interior and exterior applications. 
There is a potential for residential exposure to adult handlers making
applications to ornamentals and/or from using treated paint.  There is
also a potential for residential exposure to children from ingestion of
paint chips containing chlorothalonil, although ingestion of paint chips
is considered to be episodic in nature and is generally not included in
aggregate risk so it was therefore excluded from these assessments as
well.  The chlorothalonil non-dietary risk assessment was performed
using a short-term incidental oral and inhalation endpoint of 3.0
mg/kg-bw/day, based upon a NOAEL from a 90 day rat study in the rat and
an uncertainty factor of 100X for intra- and inter-species variability;
no additional FQPA safety factor was applied.  For the purpose of the
aggregate risk assessment, exposure values were expressed in terms of
margin of exposure (MOE), calculated by dividing the 3.0 mg/kg-bw/day
endpoint by the exposure for each population subgroup.  The most exposed
population subgroups from the non-dietary (residential) assessments was
for male adults and youths (13 years and older) attributable to
short-term inhalation exposures resulting from applying alkyd exterior
paint with an airless sprayer, with a MOE of 147.  Since the benchmark
MOE for this assessment was 100 and since EPA generally has no concern
for non-dietary exposures above the benchmark MOE, Syngenta believes
that there is a reasonable certainty that no harm will result from
non-dietary exposures from all current residential uses for
chlorothalonil.>

<D. Cumulative Effects>

<	Cumulative Exposure to Substances with a Common Mechanism of Toxicity.
 Section 408(b)(2)(D)(v) requires that, when considering whether to
establish, modify, or revoke a tolerance, the Agency consider
“available information” concerning the cumulative effects of a
particular pesticide’s residues and “other substances that have a
common mechanism of toxicity”.  Syngenta did not perform a cumulative
risk assessment as part of this tolerance action for chlorothalonil
because HED has not yet determined that there are any other chemical
substances that have a mechanism of toxicity common with that of
chlorothalonil.  For purposes of this tolerance action, EPA has assumed
that chlorothalonil does not have a common mechanism of toxicity with
any other substance(s).>

<E. Safety Determination>

<	1. U.S. population. The chronic aggregate exposure analysis (food plus
water exposures) showed that exposure from all established and proposed
uses of chlorothalonil resulted in a chronic MOE of 1,152 (8.7% of the
cRfD) which exceeds the benchmark MOE of 100.  The short-term aggregate
exposure analysis (food plus water plus non-dietary residential
exposures) showed that exposure from all established and proposed uses
of chlorothalonil resulted in a MOE of 136 for adults 50 years and
older, which exceeds the benchmark MOE of 100.  Based on the
completeness and reliability of the toxicity data supporting these
petitions, Syngenta believes that there is a reasonable certainty that
no harm will result to the U. S. population from aggregate exposures
arising from all current, pending, and proposed uses for
chlorothalonil.>

<	2. Infants and children. The chronic aggregate exposure analysis (food
plus water exposures) showed that exposure from all established and
proposed uses of chlorothalonil resulted in a MOE of 390 (25.6% of the
cRfD) for all infants <1 year old, which exceeds the benchmark MOE of
100.  The short-term aggregate exposure analysis (food plus water plus
non-dietary residential exposures) showed that exposure from all
established and proposed uses of chlorothalonil resulted in a MOE of 585
for infants <1 year old, which exceeds the benchmark MOE of 100.  Based
on the completeness and reliability of the toxicity data supporting
these petitions, Syngenta believes that there is a reasonable certainty
that no harm will result to infants and children from aggregate
exposures arising from all current, pending, and proposed uses for
chlorothalonil.>

<F. International Tolerances>

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␀, cherries, cranberries, cucumbers, melons, onions, peaches, squash,
and tomatoes.  Some incompatibilities exist between Codex MRLs and U.S.
tolerances for bananas, cabbage, cauliflower, peanuts, and sweet corn. 
No questions of compatibility exist with respect to commodities where no
Codex MRLs have been established but U.S. tolerances exist, or where
Codex MRLs have been established but U.S. tolerances do not exist.>

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