UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C.  20460

OFFICE OF           

PREVENTION, PESTICIDES

AND TOXIC SUBSTANCES

MEMORANDUM

Date:		04-SEP-2008

Subject:     Chlorothalonil.  Petition For Tolerances on Brassica Head
and Stem Subgroup 5A, Cucurbit Vegetable Group 9, Fruiting Vegetable
Group 8, Ginseng, Horseradish, Lentil, Lupin, Okra, Persimmon, Rhubarb,
Yam, Lychee, and Starfruit.  Summary of Analytical Chemistry and Residue
Data.  

 

PC Code:  081901	DP No.:  346319

Decision No.:  385118	Registration No.:  50534-188

Petition No.:  7E7270	Regulatory Action:  Section 3 Registration

Risk Assessment Type:  NA	Case No.:  NA

TXR No.:  NA	CAS No.:  1897-45-6

MRID No.:  47248501-47248506	40 CFR:  §180.275



From:		George F. Kramer, Ph.D., Senior Chemist

		Registration Action Branch (RAB1)

		Health Effects Division (HED) (7509P)

Through:	Dana M. Vogel, Branch Chief

		RAB1/HED (7509P)

To:              Susan Stanton/Daniel Rosenblatt, PM Team 05

		Registration Division (RD; 7505P)

This document was originally prepared under contract by Dynamac
Corporation (2275 Research Blvd, Suite 300; Rockville, MD 20850;
submitted 03/19/2008).  The document has been reviewed by HED and
revised to reflect current Office of Pesticide Programs (OPP) policies.

Executive Summary

Chlorothalonil [2,4,5,6-tetrachloro-1,3-benzenedicarbonitrile] is a
broad-spectrum, non-systemic protectant pesticide mainly used as a
fungicide to control fungal foliar diseases of vegetable, field, and
ornamental crops.  It is also used as a wood protectant, antimold and
antimildew agent, bactericide, microbiocide, algaecide, insecticide, and
acaricide.  The exact mechanism of action is not known.

The Interregional Research Project No. 4 (IR-4), on behalf of the
Agricultural Experiment Stations of AR, CA, DE, FL, GA, HI, ID, KY, LA,
MN, MS, NJ, NC, ND, OH, OK, OR, PR, SC, TN, TX, WA, WI, and VA, has
proposed to amend the use pattern for the 6 lb/gal flowable-concentrate
(FlC) formulation of chlorothalonil (Bravo Weather Stik®, EPA Reg. No.
50534-188-100) to add uses on ginseng, horseradish, lentil, lupin, okra,
persimmon, rhubarb, and yam.  In addition, IR-4 proposes to expand the
existing uses on broccoli, Brussels sprouts, cabbage, and cauliflower to
the Brassica head and stem subgroup (5A), the existing uses on cucumber,
melon, and squash to the cucurbit vegetable group (9), and the existing
uses on tomato to the fruiting vegetable group (8).  In conjunction with
the requested amended uses, IR-4 has submitted a petition, PP#7E7270,
for the establishment of permanent tolerances for the combined residues
of the fungicide chlorothalonil (tetrachloroisophthalonitrile) and its
metabolite 4-hydroxy-2,5,6-trichloroisophthalonitrile in or on the
following raw agricultural commodities:

Vegetables, fruiting, group 8	5.0 ppm

Vegetable, cucurbit, group 9	5.0 ppm

Okra	5.0 ppm

Persimmon	1.9 ppm

Horseradish	4.0 ppm

Rhubarb	5.0 ppm

Ginseng	3.0 ppm

Yam	5.0 ppm

Lupin	0.1 ppm

Lentil	0.1 ppm

Brassica, head and stem, subgroup 5A	5.0 ppm

RD has also requested that HED recommend levels for tolerances on lychee
and starfruit in order to alleviate trade irritant issues with the
government of Taiwan.  Based on translation from existing tolerances on
tropical fruits, HED recommends for tolerances of 15 ppm for lychee and
3 ppm for starfruit.  

Tolerances for chlorothalonil residues are established under 40 CFR
§180.275.  Tolerances are established in 40 CFR §180.275(a)(1) for the
combined residues of chlorothalonil and its 4-hydroxy metabolite
(4-hydroxy-2,5,6-trichloroisophthalonitrile) for various plant
commodities.  Tolerances range from 0.05 ppm (almonds and dried cocoa
bean) to 15 ppm (celery and papaya).  Tolerances for livestock
commodities are established under 40 CFR §180.275(a)(2) and expressed
in terms of the 4-hydroxy metabolite; tolerances range from 0.03 ppm
(meat of cattle, goat, hog, horse, and sheep) to 0.5 ppm (kidney of
cattle, goat, hog, horse, and sheep).  A time-limited tolerance is
established in 40 CFR §180.275(b) for the combined residues of
chlorothalonil and its 4-hydroxy metabolite (expressed as
chlorothalonil) in/on ginseng at 0.10 ppm; the tolerance has an
expiration date of 12/31/08.  Tolerances with regional registration are
established in 40 CFR §180.275(c) for the combined residues of
chlorothalonil and its metabolite in/on hazelnut at 0.1 ppm and mint hay
at 2 ppm.

The qualitative nature of the residue in plants is adequately understood
based on acceptable metabolism studies with carrots, celery, lettuce,
snap beans, and tomatoes.  The residues of concern are chlorothalonil
and its 4-hydroxy metabolite.

The qualitative nature of the residue in livestock is adequately
understood.  The residue of concern in meat and milk is the 4-hydroxy
metabolite of chlorothalonil (SDS-3701).  Chlorothalonil per se has been
shown to be so unstable in ruminant tissues that it is impractical to
establish tolerances that include the parent.  The only livestock
feedstuff associated with the proposed uses is lupin seed, a minor
poultry feedstuff.  No changes in the existing tolerances for livestock
commodities are needed to support the proposed uses of chlorothalonil.

An adequate gas chromatography (GC) method with electron-capture
detection (ECD) is available for tolerance enforcement for plant
commodities.  The validated limits of quantitation (LOQs) were
0.020-0.20 ppm for chlorothalonil and its 4-hydroxy metabolite.  Samples
from the submitted field trials were analyzed for residues of
chlorothalonil and its 4-hydroxy metabolite using adequate GC/ECD
methods similar to the existing enforcement method.   

To support the proposed uses, IR-4 submitted crop field trial data for
ginseng, horseradish, bell and non-bell pepper, persimmon, and rhubarb. 
Adequate storage stability data have been submitted previously which
support the submitted crop field trial studies with horseradish, bell
and non-bell pepper, persimmon, and rhubarb.  A concurrent storage
stability study was conducted with ginseng which indicated the potential
for decline of chlorothalonil during storage; sample results for ginseng
were corrected for this decline.  

Adequate field trial data have been submitted to support the requested
new uses of the 6 lb/gal FlC formulation (EPA Reg. No. 50534-188-100) on
ginseng, horseradish, persimmon, and rhubarb.  Label amendments for
persimmon are required before the requested uses may be approved. 
Additional crop field trial data are required for non-bell pepper to
support the proposed use; submission of these data may be considered a
condition of registration.  The submitted data for bell and non-bell
peppers and the existing residue data for tomato may be used to support
the proposed uses on fruiting vegetables and okra.  

The petitioner is relying on existing residue data for broccoli,
Brussels sprouts, cabbage, and cauliflower to support the proposed uses
on the Brassica head and stem subgroup; for cucumber, melon, pumpkin,
and summer and winter squash to support the proposed uses on the
cucurbit vegetable group; for dry bean to support the proposed use on
lentil; and for potato to support the proposed use on yam.  The existing
residue data are adequate to support proposed uses provided the proposed
use on the Brassica head and stem subgroup is modified to specify a
lower maximum seasonal rate.  

The available data indicate that the proposed tolerance for residues
in/on ginseng is too low and the proposed tolerances for persimmon,
rhubarb, and yam are too high; tolerances of 4.0 ppm for residues in/on
ginseng and rhubarb, 1.5 ppm for persimmon, and 0.10 ppm for yam would
be appropriate.  The proposed tolerances for residues in/on Brassica
head and stem subgroup 5A, horseradish, lentil, okra, and cucurbit
vegetable group 9 are appropriate.  Since the use directions for
tomatoes and the other fruiting vegetables differ significantly,
separate tolerances should be established for “tomato” and
“vegetable, fruiting, group 8, except tomato.”  The recommended
tolerance for vegetable, fruiting, group 8, except tomato is 6.0 ppm,
based on residue data from bell pepper.  

The proposed use and tolerance for lupin are not needed as
chlorothalonil is already registered for use on lupin (as part of the
use directions for dry bean), and the established 0.1-ppm tolerance for
dry bean seed is adequate to cover residues in/on lupin [40 CFR
§180.1(g)].

Adequate confined and field rotational crop data have been submitted
previously.  The only residue detected in rotated crops was the soil
metabolite 3-carbamyl-2,4,5-trichlorobenzoic acid (SDS-46851).  Because
of the low toxicity of this metabolite, an exemption for the requirement
of a tolerance for residues of SDS-46851, as inadvertent residues in
rotated crops, has been established (40 CFR §180.1110).  Rotational
crop restrictions are not needed for the registered or proposed uses of
chlorothalonil.  

The Codex Alimentarius Commission has established maximum residue limits
(MRLs) for chlorothalonil per se in/on several commodities, including
dry beans, broccoli, Brussels sprouts, cabbage, cauliflower, cucumber,
melons (except watermelon), sweet pepper, squash (summer and winter),
and tomato.  Mexican MRLs for “clorotalonil” have been established
for bean, broccoli, Brussels sprouts, cabbage, cauliflower, cucumber,
melon, squash, and tomato.  As the U.S. tolerance definition differs
from the Codex and Mexican definitions, harmonization is not possible. 
Canadian MRLs for chlorothalonil and its 4-hydroxy metabolite are
established for beans, broccoli, Brussels sprouts, cabbage, cauliflower,
cucumber, melons, pumpkins, squash, and tomatoes.  With the exception of
beans (which presumably includes dried beans), the Canadian MRLs are
harmonized with U.S. tolerances.  

  SEQ CHAPTER \h \r 1 Regulatory Recommendations and Residue Chemistry
Deficiencies

Pending submission of revised Sections B (see requirements under
Directions for Use) and F (see requirements under Proposed Tolerances),
and submission of a reference standard for the 4-hydroxy metabolite (see
requirements under Submittal of Analytical Reference Standards), there
are no residue chemistry issues that would preclude granting:  a
conditional registration for the requested uses of chlorothalonil on
fruiting vegetables (Crop Group 8); unconditional registration for the
requested uses of chlorothalonil on cucurbit vegetables (Crop Group 9),
ginseng, horseradish, head and stem Brassica (Subgroup 5A), lentil,
okra, persimmon, rhubarb, and yam; and establishment of the following
permanent tolerances for combined residues of chlorothalonil and its
4-hydroxy metabolite:  

	under 40 CFR §180.275(a)(1):

Brassica, head and stem, subgroup 5A	5.0 ppm

Ginseng	4.0 ppm

Horseradish	4.0 ppm

Lentil	0.10 ppm

Okra	6.0 ppm

Rhubarb	4.0 ppm

Vegetable, cucurbit, group 9	5.0 ppm

Vegetable, fruiting, group 8, except tomato	6.0 ppm

Yam	0.10 ppm

Lychee	15 ppm

Starfruit	3.0 ppm

	under 40 CFR §180.275(c):

Persimmon	1.5 ppm

A human-health risk assessment is forthcoming.

Note to PM:  On establishment of the recommended tolerances, the
following tolerances should be removed from 40 CFR §180.275(a)(1):  

Broccoli	5 ppm

Brussels sprouts	5 ppm

Cabbage	5 ppm

Cauliflower	5 ppm

Cucumber	5 ppm

Melon	5 ppm

Pepper, non-bell	5 ppm

Pumpkin	5 ppm

Squash, summer	5 ppm

Squash, winter	5 ppm

and the following tolerance should be removed from 40 CFR §180.275(b): 


Ginseng	0.10 ppm (12/31/08 expiration date)

860.1200 Directions for Use

The proposed uses on the Brassica head and stem subgroup should be
revised to specify a maximum seasonal application rate of 8.8 lb ai/A.

The proposed use on persimmon should be modified to specify that
chlorothalonil may only be applied to persimmon grown in Florida and
Hawaii, and that applications may be made with a minimum retreatment
interval (RTI) of 14 days.  In addition, the proposed use should specify
that aerial applications to persimmon be made in a minimum of 10 gal/A.

860.1550 Proposed Tolerances

The petitioner should submit a revised Section F reflecting the
recommended tolerances and commodity definitions presented above and in
Table 6.

860.1650 Submittal of Analytical Reference Standards

The analytical reference standard for 4-hydroxy chlorothalonil at the
EPA National Pesticide Standards Repository has expired.  The registrant
should either recertify the lot in the repository and send in an updated
certificate of analysis (COA), or submit a new standard (different lot
#) if the previous lot will not be recertified.  

HED recommends that conversion of conditional registration to
unconditional registration for the requested uses on fruiting vegetables
may be considered upon submission of the following outstanding residue
chemistry data.

860.1500 Crop Field Trials

To support use of the FlC formulation on non-bell peppers, the
petitioner should conduct one additional side-by-side field trial with
non-bell peppers.  The trial should reflect side-by-side plots receiving
applications of the FlC and water-dispersible granule (WDG) formulations
at 1x the proposed maximum seasonal rate, and the trial should be
conducted in Zone 8.  If the trial indicates that residues in/on samples
treated with the FlC formulation are higher than in/on samples treated
with the WDG formulation, two additional field trials will be required,
so that a total of three field trials are available reflecting
application of the FlC formulation to non-bell peppers.  

Background

The chemical structure and nomenclature of chlorothalonil and its
4-hydroxy metabolite and the physicochemical properties of the technical
grade of chlorothalonil are presented in Tables 1 and 2.  

TABLE 1.  Test Compound Nomenclature.

Compound	

Common name	Chlorothalonil

Company experimental name	N/A

IUPAC name	tetrachloroisophthalonitrile

CAS name	2,4,5,6-tetrachloro-1,3-benzenedicarbonitrile

CAS registry number	1897-45-6

End-use product (EP)	Bravo Weather Stik® (6 lb/gal FlC formulation; EPA
Reg. No. 50534-188)

Compound	

Common name	4-Hydroxy metabolite

Company experimental name	SDS-3701

IUPAC name	2,4,5-trichloro-6-hydroxyisophthalonitrile

CAS name	4-hydroxy-2,5,6-trichloro-1,3-benzenedicarbonitrile

CAS registry number	Not provided



TABLE 2.  Physicochemical Properties of the Technical Grade Test
Compound:  Chlorothalonil. 

Parameter	Value	Reference

Melting range	250-251 (C	Chlorothalonil Reregistration Eligibility
Decision, April 1999

Water solubility	0.6 ppm (25 °C)	Chlorothalonil Reregistration
Eligibility Decision, April 1999

Solvent solubility	g/L at 25 °C:

acetone	20

dimethyl sulfoxide	20

cyclohexanone	30

dimethylformamide	30

kerosene	<10

xylene	80	The Pesticide Manual, 8th ed.

Octanol/water partition coefficient, Log(KOW)	4.37 x 102	TOXNET database



860.1200 Directions for Use

IR-4 included a copy of an existing label for the 6 lb/gal FlC
formulation (EPA Reg. No. 50534-188-100), and provided a description of
the proposed use patterns for the Brassica head and stem subgroup, the
cucurbit vegetable group, the fruiting vegetable group, ginseng,
horseradish, lentil, lupin, okra, persimmon, rhubarb, and yam.  The
proposed uses are summarized in Table 3.

Table 3.  Summary of Directions for Use of Chlorothalonil.

Applic. Timing, Type, and Equip.	Formulation

[EPA Reg. No.]	Applic. Rate 

(lb ai/A)	Max. No. Applic. per Season	Max. Seasonal Applic. Rate

(lb ai/A)	PHI

(days)	Use Directions and Limitations

Brassica, head and stem, subgroup 5A

Postemergence

Broadcast foliar	6 lb/gal FlC

[50534-188-100]	1.13-1.5	Not specified	12	7	A minimum RTI of 7 days is
proposed.

Cucurbit vegetable, group 9

Postemergence

Broadcast foliar	6 lb/gal FlC

[50534-188-100]	1.13-2.25	Not specified	15.8	0	A minimum RTI of 7 days
is proposed.

Fruiting vegetables, group 8 and Okra

Postemergence

Broadcast foliar	6 lb/gal FlC

[50534-188-100]	1.13	8 (implied)	9	3	A minimum RTI of 7 days is
proposed.

Ginseng

Postemergence

Broadcast foliar	6 lb/gal FlC

[50534-188-100]	1.5	8 (implied)	12	14	A minimum RTI of 7 days is
proposed.

Horseradish

Postemergence

Broadcast foliar	6 lb/gal FlC

[50534-188-100]	2.25	8 (implied)	18	14	A minimum RTI of 7 days is
proposed.

Lupin and lentil

Postemergence

Broadcast foliar	6 lb/gal FlC

[50534-188-100]	0.75-1.13	Not specified	6	14	A minimum RTI of 7 days is
proposed.

Persimmon

Postemergence

Broadcast foliar	6 lb/gal FlC

[50534-188-100]	0.94	5 (implied)	4.7	14	A minimum RTI of 10 days is
proposed.

Rhubarb

Postemergence

Broadcast foliar	6 lb/gal FlC

[50534-188-100]	2.25	6 (implied)	13.5	30	A minimum RTI of 7 days is
proposed.

Yam

Postemergence

Broadcast foliar	6 lb/gal FlC

[50534-188-100]	0.75-1.13	Not specified	11.3	7	A minimum RTI of 7 days
is proposed.



The proposed use directions do not include any information pertaining to
application equipment or volumes; the petitioner referred to the
registered label for general product information.  The product label
included in the submission for EPA Reg. No. 50534-188-100 specifies that
applications may be made using ground or aerial equipment.  A minimum
spray volume of 5 gal/A for ground and aerial equipment is specified for
applications to field and row crops.  For tree and orchard crops, the
label specifies that the product should be applied in sufficient volume
to obtain adequate coverage of the tree canopy.  The general use
directions on the parent label do not specify minimum spray volumes for
tree and orchard crops [the individual directions for these crops
include spray volume information].

Conclusions.  The proposed use directions are adequate to allow
evaluation of the residue data relative to the proposed use.  Label
revisions are required for some crops to reflect the field trial
parameters.  The proposed uses on the Brassica head and stem subgroup
should be revised to specify a maximum seasonal application rate of 8.8
lb ai/A.  The proposed use on persimmon should be modified to specify
that chlorothalonil may only be applied to persimmon grown in Florida
and Hawaii and that applications may be made with a minimum RTI of 14
days.  In addition, the proposed use should specify that aerial
applications to persimmon be made in a minimum of 10 gal/A.

HED notes that use of the 6 lb/gal FlC formulation (EPA Reg. No.
50534-188) on lupin exists on the current label (label accepted
9/27/05), as part of the uses on dry beans.

The submitted data for pepper (bell and non-bell) support the proposed
use pattern for the fruiting vegetables crop group.  However, existing
product labels allow a less restrictive use on tomatoes, which is
supported by adequate data:  multiple foliar applications to tomatoes at
up to 2.1 lb ai/A/application, with a maximum seasonal rate of 15 lb
ai/A and a 0-day PHI.  HED concludes that the product label for the 6
lb/gal FlC formulation (EPA Reg. No. 50534-188) should have separate use
directions for “Tomato” and “Fruiting vegetables, other than
tomato.”  

860.1300 Nature of the Residue - Plants

Residue Chemistry Chapter of the HED Chapter of the RED, DP# 201522,
6/13/95, W. Smith

  SEQ CHAPTER \h \r 1 The qualitative nature of the residue in plants is
adequately understood based on acceptable metabolism studies with
carrots, celery, lettuce, snap beans, and tomatoes.  The residues of
concern are chlorothalonil and its 4-hydroxy metabolite, SDS-3701.  

860.1300 Nature of the Residue - Livestock

Residue Chemistry Chapter of the HED Chapter of the RED, DP# 201522,
6/13/95, W. Smith

Residue Chemistry Memo DP# 220825, 3/5/96, W. Smith (PP#6F4611)

The qualitative nature of the residue in livestock is adequately
understood.  The residue of concern in meat and milk is SDS-3701. 
Chlorothalonil per se has been shown to be so unstable in ruminant
tissues that it is impractical to establish tolerances that include the
parent.  

Based on poultry metabolism studies using [14C]chlorothalonil and
4-hydroxy-[14C]chlorothalonil, HED concluded that there is no
significant transfer of chlorothalonil to poultry tissues or eggs, and
that levels of transfer of the 4-hydroxy metabolite are too low to
require feeding studies or tolerances for poultry commodities.

860.1340 Residue Analytical Methods

Plant commodities

Residue Chemistry Chapter of the HED Chapter of the RED, DP# 201522,
6/13/95, W. Smith

Enforcement methods:  The Pesticide Analytical Manual (PAM) Vol. II
lists Method I, a GC/ECD method, for the enforcement of tolerances for
plant commodities.  The limit of detection (LOD) is 0.01 ppm for both
chlorothalonil and its 4-hydroxy metabolite.

In addition, the registrant had proposed a GC/ECD method, entitled
“General Analytical Procedure for the Determination of Residues of
Chlorothalonil (SDS-2787), SDS-3701, SDS-46851, HCB and PCBN on Selected
Crops,” for enforcement of tolerances for peanuts, potatoes, and
tomatoes.  The method is a modification of the current enforcement
method and has been subjected to an adequate independent laboratory
validation (ILV; CB No. 7029, 2/22/91, W.T. Chin).  

Data-collection methods:  Samples of crop commodities from the submitted
field trials with ginseng, horseradish, bell and non-bell pepper,
persimmon, and rhubarb were analyzed for residues of chlorothalonil and
its metabolite SDS-3701 using modified versions of the previously
proposed GC/ECD enforcement method entitled “General Analytical
Procedure for the Determination of Residues of Chlorothalonil
(SDS-2787), SDS-3701, SDS-46851, HCB and PCBN on Selected Crops.”  In
all cases, the validated LOQ was used as the limit for reporting
purposes.  The validated LOQs were 0.02 ppm for chlorothalonil and 0.2
ppm for SDS-3701 in/on ginseng; 0.02 ppm for chlorothalonil and SDS-3701
in/on horseradish and rhubarb; 0.03 ppm for chlorothalonil and SDS-3701
in/on bell and non-bell pepper; 0.10 ppm for chlorothalonil and SDS-3701
in/on persimmon.

Briefly, for all crops except ginseng, samples were extracted with
acidic acetone and the extract was concentrated to remove the acetone. 
The pH of the extract was adjusted to 4.5 and the extract was
partitioned with petroleum ether; residues of chlorothalonil partitioned
into the organic phase, and residues of SDS-3701 partitioned into the
aqueous phase.  For chlorothalonil, the organic phase was concentrated
and redissolved in dichloromethane/hexane.  Chlorothalonil were
separated on a Florisil column, using
dichloromethane/hexane/acetonitrile to elute chlorothalonil residues. 
The fractions were concentrated and redissolved in toluene for separate
GC/ECD analysis.

For SDS-3701, the pH of the aqueous phase was adjusted to <2, sodium
chloride was added, and residues were partitioned into diethyl ether. 
The combined organic phases were concentrated and SDS-3701 was converted
to its methyl ester derivative using diazomethane.  The derivatized
residues were cleaned up on an activated alumina column, using methylene
chloride to elute residues.  The eluate was concentrated and redissolved
in toluene for GC/ECD analysis.  For persimmon, SDS-3701 was cleaned up
on a Florisil column prior to derivatization; no column cleanup was
conducted after derivatization.  

For chlorothalonil in ginseng, samples were extracted using a mixture of
acetonitrile and 5 M sulfuric acid.  The extract was concentrated to
remove acetonitrile and partitioned twice with diethyl ether.  The
combined organic phases were partitioned with a saturated sodium
chloride solution.  The organic phase was concentrated and redissolved
in 5% acetone in dichloromethane and applied to a Florisil column, using
5% acetone in dichloromethane to elute residues of chlorothalonil.  The
eluate was evaporated to dryness and redissolved in toluene for GC/ECD
analysis.  For SDS-3701 analysis, ginseng samples were extracted using a
mixture of acetone and 50% sulfuric acid.  The extract was concentrated
to remove acetone and 0.35 M aqueous sodium bicarbonate and sodium
chloride were added.  The pH was adjusted using 50% sulfuric acid and
the extract was partitioned twice with ethyl ether/petroleum ether.  The
combined organic phases were evaporated to dryness, dissolved in 5%
acetone in dichloromethane, and cleaned up on Florisil column, using 50%
acetone in dichloromethane to elute residues.  The extracts were
derivatized using 3-methyl-1-p-tolytriazene in ethyl ether.  The
derivatized residues were concentrated and diluted to volume with
acetone for GC/ECD analysis.

These methods were adequate for data collection purposes for
chlorothalonil and SDS-3701 based on acceptable method validation and/or
concurrent recovery data.  

Conclusions.  The submitted data are adequate to satisfy data
requirements for residue analytical methods for plant commodities.  An
adequate method exists for the enforcement of the proposed tolerances
for combined residues of chlorothalonil and SDS-3701.  Samples of crop
commodities were analyzed using adequate data collection methods.  

Livestock commodities

Because no tolerances are required for livestock commodities as a result
of the proposed uses, no enforcement methods for livestock commodities
are needed.

860.1360 Multiresidue Methods

The FDA PESTDATA database (dated 06/05) indicates that chlorothalonil is
completely recovered (>80%) using FDA multiresidue method Sections 302
(Protocol D), 303 (Protocol E), and 304 (Protocol F).  The database also
contains information for chlorothalonil trichloro impurity
(trichloroisophthalonitrile), which is recovered (no quantitative
information available) using Sections 302 and 303 but is not recovered
using Section 304.  Hexachlorobenzene is completely recovered using
Sections 302 and 303, with variable recovery using Section 304.  

The database does not contain any information for the 4-hydroxy
metabolite.  It appears that in the Chlorothalonil Residue Chemistry RED
Chapter, the multiresidue method recovery data for chlorothalonil
trichloro impurity were incorrectly attributed to the 4-hydroxy
metabolite; see DP# 228522, W. Smith.  

860.1380 Storage Stability

Residue Chemistry Chapter of the HED Chapter of the RED, DP# 201522,
6/13/95, W. Smith

Residue Chemistry Memo, DP# 235069, 6/30/97, W. Smith

Adequate storage stability data for residues of chlorothalonil and
SDS-3701 in/on a variety of commodities have been submitted previously. 
In the 6/13/95 Residue Chemistry Chapter  SEQ CHAPTER \h \r 1   SEQ
CHAPTER \h \r 1 , it was concluded that residues of chlorothalonil and
SDS-3701 are stable during frozen storage for up to 4 years in/on
carrots, celery, cherries, cucumbers, potatoes, soybeans, tomatoes, and
wheat grain.  In peanuts, residues of SDS-3701 are stable during up to 4
years of frozen storage; residues of chlorothalonil declined by
approximately 9% per year in peanuts.  The final report of the storage
stability study, which included storage stability data for
chlorothalonil and SDS-3701 in/on almonds, almond hulls, carrots,
celery, cherries, cucumbers, potatoes, soybeans, tomato, and wheat grain
over a 6-year period, was submitted and reviewed in 1997 (DP# 235069). 
It was concluded that chlorothalonil residues of concern are stable
during frozen storage intervals such as incurred in completing field
trial residue studies in support of reregistration. 

In addition, a supporting storage stability study was conducted in
conjunction with the ginseng field trials (MRID 47248506).  Samples of
untreated dry ginseng root were fortified with chlorothalonil and
SDS-3701 at 0.20 and 2.0 ppm and stored frozen for up to 541-548 days. 
No zero-day data were provided.  The concurrent storage stability data
suggest that residues of chlorothalonil were not stable during the
storage durations of the samples from the ginseng field trials,
declining ~40%.  

The storage durations and conditions of samples from the crop field
trials submitted to support this petition are presented in Table 4.  

Table 4.  Summary of Storage Conditions and Durations of Samples from
Crop Field Trial Studies.  

Matrix 	Storage Temperature (°C)	Actual Storage Duration	Interval of
Demonstrated Storage Stability

Ginseng	-29 to -15	576-591 days

(18.9-19.4 months)	A concurrent storage stability study indicates that
chlorothalonil residues declined ~40 % during frozen storage for up to
541-548 days.

Horseradish	-21 ± 7	92-118 days

(3.0-3.9 months)	Residues of chlorothalonil and SDS-3701 are stable
in/on carrots during up to 4 years of frozen storage.

Pepper, bell	 -21 ± 7	71-301 days

(2.3-9.9 months)	Residues of chlorothalonil and SDS-3701 are stable
in/on tomatoes during up to 4 years of frozen storage.

Pepper, non-bell	 -21 ± 7	26-90 days 

(0.9-3.0 months)

	Persimmon	-20 ± 5	380-540 days 

(12.5-17.8 months)	Residues of chlorothalonil and SDS-3701 are stable
in/on various crops, including cherries and tomatoes, during up to 4
years of frozen storage.

Rhubarb	-21 ± 7	140-173 days

(4.6-5.7 months)	Residues of chlorothalonil and SDS-3701 are stable
in/on celery during up to 4 years of frozen storage.



Conclusions.  The storage conditions and durations of samples from the
ginseng, horseradish, pepper (bell and non-bell), persimmon, and rhubarb
field trials are supported by adequate storage stability data.  No
additional storage stability data are required.  The available data
indicate that no corrections for decline during storage are needed for
the horseradish, pepper (bell and non-bell), persimmon, and rhubarb
residue studies; however, correction of chlorothalonil residues is
necessary for the ginseng residue study.

Although zero-day data were not provided, the concurrent storage
stability data for ginseng suggest that residues of chlorothalonil
decline during frozen storage.  Because the interval of the concurrent
storage stability study approximates the storage durations of field
trial samples, residues of chlorothalonil in/on ginseng were corrected
for a ~40% decline. 

IR-4 is reminded that storage stability studies should always include a
zero-day sampling interval to establish the residue levels present at
the time samples are placed into storage [see OPPTS 860.1380(d)(6)(i)]. 


860.1480 Meat, Milk, Poultry, and Eggs

Residue Chemistry Chapter of the HED Chapter of the RED, DP# 201522,
6/13/95, W. Smith

No livestock feeding studies were submitted with this petition.  HED has
previously concluded that no poultry feeding studies or tolerances for
poultry commodities were needed to support the uses that were registered
at the time of the RED.  The only livestock feedstuff associated with
this petition is lupin seed, which may be fed to poultry.  Since lupin
seed is a minor poultry feedstuff (fed at a maximum of 10% of diet;
OPPTS 860.1000 Table 1 Feedstuffs, October 2006) and based on an
estimated residue of 0.10 ppm, the proposed use of chlorothalonil on
lupin will not significantly affect the dietary burden of chlorothalonil
to poultry.  Therefore, no feeding studies or tolerances for livestock
commodities are required to support the proposed uses.

860.1500 Crop Field Trials

Root and Tuber Vegetable (group 1)

Ginseng

DER Reference:	47248506.der.doc

IR-4 has submitted field trial data for chlorothalonil on ginseng. 
Three field trials were conducted in the U.S. in Zone 5 (WI) during the
2004 growing season.  At each trial site, the treated plot received
eight broadcast foliar applications of a 6 lb/gal FlC formulation of
chlorothalonil at a rate of 1.4-1.6 lb ai/A/application, with 6- to
8-day RTIs, for a total seasonal rate of 12.2-12.5 lb ai/A (~1x the
proposed maximum seasonal rate).  Applications were made in 167-193
gal/A spray volumes without an adjuvant.  Mature ginseng roots were
harvested 6-8 days after the last application.  

Samples were analyzed for residues of chlorothalonil and SDS-3701 using
an adequate GC/ECD method.  The validated LOQ was 0.02 ppm for
chlorothalonil and 0.2 ppm for SDS-3701.  Samples were stored frozen
from collection to analysis for a maximum of 591 days.  The results of a
concurrent storage stability study indicated that residues of
chlorothalonil declined ~40% during storage for 548 days.  

The results of the ginseng field trials are summarized in Table 5.1. 
Maximum combined residues of chlorothalonil and SDS-3701 were 1.76 ppm
in/on ginseng root.  Maximum individual residues of chlorothalonil and
SDS-3701 were 1.01 ppm and 0.75 ppm, respectively.  When chlorothalonil
and SDS-3701 residues are corrected for potential decline during
storage, residues were 0.32-1.68 ppm for chlorothalonil, 0.20-0.88 ppm
for SDS-3701, and 0.52-2.57 ppm for combined residues.  

Table 5.1.  Summary of Residue Data from Ginseng Field Trials with
Chlorothalonil.

Crop matrix	Total Applic. Rate (lb ai/A)	PHI (days)	Combined Residue
Levels (ppm)1



	n	Min.	Max.	HAFT2	Median	Mean	Std. Dev.

Ginseng (proposed use = 12 lb ai/A total application rate, 14-day PHI)

Ginseng (dried root) 	12.2-12.5	6-8	6	<0.39

(<0.52)	1.76

(2.43)	1.39

(1.91)	0.65

(0.88)	0.81

(1.11)	0.52

(0.76)

1  Combined Residues = chlorothalonil + SDS-3701; residues presented in
parentheses are corrected for apparent freezer storage loss (40% decline
for chlorothalonil).

2  HAFT = Highest-average field trial result.

Conclusions.  The submitted residue data for ginseng are adequate.  The
number and locations of crop field trials are in accordance with OPPTS
Guideline 860.1500.  The application rates in the trials reflect the
proposed use pattern; however, the PHIs of the field trials, 6-8 days,
are shorter than the proposed PHI of 14 days.  However, as ginseng is a
minor crop, HED will not require that the petitioner submit additional
residue data with the proposed PHI.

The residue data, corrected for potential decline during storage, will
support a tolerance for the combined residues of chlorothalonil and
SDS-3701 in/on ginseng at 4.0 ppm; the tolerance calculation for ginseng
is presented in Appendix I.  The tolerance level recommendation is
higher than the level proposed by the petitioner.

Horseradish

DER Reference:	47248504.der.doc

IR-4 has submitted field trial data for chlorothalonil on horseradish. 
Three field trials were conducted in the U.S. in Zones 2 (MD and NJ; 2
trials) and 5 (WI; 1 trial) during the 2002 growing season.  At each
trial site, the treated plot received eight foliar applications of a 6
lb/gal FlC formulation of chlorothalonil at a target rate of 2.25 lb
ai/A/application for a total seasonal rate of ~18.0 lb ai/A (1x the
proposed maximum seasonal rate).  Applications were made as directed
foliar sprays at one of the trial sites and as broadcast foliar sprays
at the other two trial sites; RTIs were 6 to 8 days.  Applications were
made in 33-70 gal/A spray volumes without an adjuvant.  Mature
horseradish roots were harvested 12-15 days after the last application. 


Samples were analyzed for residues of chlorothalonil and SDS-3701 using
an adequate GC/ECD method.  The validated LOQ was 0.02 ppm for
chlorothalonil and SDS-3701.  Sample storage durations and conditions
are reported in Table 4.  Adequate storage stability data are available
to support sample storage durations and conditions.  

The results of the horseradish field trials are summarized in Table 5.2.
 Maximum combined residues of chlorothalonil and SDS-3701 were 0.63 ppm
in/on horseradish harvested 12-15 days after the final application of
chlorothalonil.  Maximum individual residues of chlorothalonil and
SDS-3701 were 0.48 ppm and 0.29 ppm, respectively.  

Table 5.2.  Summary of Residue Data from Horseradish Field Trials with
Chlorothalonil.

Crop matrix	Total Applic. Rate (lb ai/A)	PHI (days)	Combined Residue
Levels (ppm)1



	n	Min.	Max.	HAFT2	Median	Mean	Std. Dev.

Horseradish (proposed use = 18 lb ai/A total application rate, 14-day
PHI)

Horseradish	17.8-18.2	12-15	6	<0.045	0.63	0.53	0.47	0.37	0.25

1  Combined Residues = chlorothalonil + SDS-3701.

2  HAFT = Highest-average field trial result.

Conclusions.  The submitted residue data for horseradish are adequate. 
The number and locations of crop field trials are in accordance with
OPPTS Guideline 860.1500.  The trials reflect the proposed use pattern. 
Although the trials reflected both foliar directed and foliar broadcast
applications, the petitioner has proposed that chlorothalonil
applications be made to horseradish as broadcast foliar applications.

The residue data will support a tolerance for the combined residues of
chlorothalonil and SDS-3701 in/on horseradish at 4.0 ppm; the tolerance
calculation for horseradish is presented in Appendix I.  

Yam

No yam residue data were submitted in support the proposed use on yam. 
IR-4 has proposed to translate the existing potato data to yam since
potato is the representative crop for crop subgroup 1C, tuberous and
corm vegetables, which includes yam.  A tolerance for the combined
residues of chlorothalonil and its 4-hydroxy metabolite in/on potato has
been established at 0.1 ppm [40 CFR §180.275(a)(1)].

The proposed use of the 6 lb/gal FlC formulation on yam is very similar
to the existing uses of chlorothalonil on potato on the product label
for the 6 lb/gal FlC formulation (EPA Reg. No. 50534-188; label accepted
9/27/05):  multiple applications at up to 1.125 lb ai/A/application with
a maximum seasonal rate of 11.3 lb ai/A and a 7-day PHI.  HED has
approved a use pattern for potato of a maximum seasonal rate of 12 lb
ai/A with a 7-day PHI (DP#s 213088, 213193, 213196, and 213200, 8/9/95,
W. Smith).  

Conclusions.  The available potato crop field trial data may be
translated to support the proposed use on yam.  The data will support a
tolerance of 0.10 ppm for combined residues of chlorothalonil and
SDS-3701 in/on yam.  The proposed tolerance for yam of 5.0 ppm listed in
Section F of the petition appears to be a typographical error, as the
text portion of the petition document indicates that IR-4 is requesting
at 0.1-ppm tolerance for yam.  

Leafy Vegetable, except Brassica (group 4)

Rhubarb

DER Reference:	47248505.der.doc

IR-4 has submitted field trial data for chlorothalonil on rhubarb.  Four
field trials were conducted in the U.S. in Zones 5 (MI; 1 trial), and 12
(OR; 3 trials) during the 2002 growing season.  At each trial site, the
treated plot received six broadcast foliar applications of a 6 lb/gal
FlC formulation of chlorothalonil at a target rate of 2.25 lb
ai/A/application, with 6- to 8-day RTIs, for a total seasonal rate of
~13.5 lb ai/A (1x the proposed maximum seasonal rate).  Applications
were made in 35-72 gal/A spray volumes without an adjuvant.  Mature
rhubarb samples were harvested 27-34 days after the last application.  

Samples of rhubarb were analyzed for residues of chlorothalonil and
SDS-3701 using an adequate GC/ECD method.  The validated LOQ was 0.02
ppm for chlorothalonil and SDS-3701.  Sample storage conditions and
durations are reported in Table 4.  Adequate storage stability data are
available to support sample storage durations and conditions.  

The results of the rhubarb field trials are summarized in Table 5.3. 
Maximum combined residues of chlorothalonil and SDS-3701 were <3.92 ppm
in/on rhubarb harvested 27-34 days after the final application of
chlorothalonil; maximum individual residues of chlorothalonil were 3.9
ppm.  Residues of SDS-3701 were below the LOQ in/on all samples.

Table 5.3.  Summary of Residue Data from Rhubarb Field Trials with
Chlorothalonil.

Crop matrix	Total Applic. Rate (lb ai/A)	PHI (days)	Combined Residue
Levels (ppm)1



	n	Min.	Max.	HAFT2	Median	Mean	Std. Dev.

Rhubarb (proposed use = 13.5 lb ai/A total application rate, 30-day PHI)

Rhubarb	13.5-14.5	27-34	8	<0.11	<3.92	<2.77	0.54	1.04	1.27

1  Combined Residues = chlorothalonil + SDS-3701.

2  HAFT = Highest-average field trial result.

Conclusions.  The submitted residue data for rhubarb are adequate.  The
number and locations of crop field trials are in accordance with OPPTS
Guideline 860.1500.  The trials reflect the proposed use pattern.

The residue data will support a tolerance for the combined residues of
chlorothalonil and SDS-3701 in/on rhubarb at 4.0 ppm; the tolerance
calculation for rhubarb is presented in Appendix I.  The tolerance level
recommendation is lower than the level proposed by the petitioner.

Brassica , head and stem, (subgroup 5A)

Residue Chemistry Chapter of the HED Chapter of the RED, DP# 201522,
6/13/95, W. Smith

No new head and stem Brassica crop field trial data were submitted. 
Individual tolerances for the combined residues of chlorothalonil and
its 4-hydroxy metabolite in/on broccoli, Brussels sprouts, cabbage, and
cauliflower have each been established at 5 ppm [40 CFR
§180.275(a)(1)].  IR-4 has proposed to convert these individual
tolerances to a crop subgroup 5A tolerance at the same level.  The
representative commodities of the head and stem Brassica subgroup are
broccoli/cauliflower and cabbage.

The proposed uses on the Brassica head and stem subgroup are identical
to the existing uses on broccoli, Brussels sprouts, cabbage, and
cauliflower on the product label for the 6 lb/gal FlC formulation (EPA
Reg. No. 50534-188; label accepted 9/27/05):  multiple applications at
1.125-1.5 lb ai/A/application with a maximum seasonal rate of 12 lb ai/A
and a 7-day PHI.  It was concluded in the 6/13/95 Residue Chemistry
Chapter that   SEQ CHAPTER \h \r 1   SEQ CHAPTER \h \r 1   SEQ CHAPTER
\h \r 1 adequate field trial data were available to support use of
chlorothalonil on broccoli, Brussels sprouts, cabbage, and cauliflower,
provided all pertinent product labels were amended to specify a 7-day
PHI and a maximum number of applications or a maximum seasonal rate; the
available data supported:  (i) a maximum of 8 applications per season at
1.1 lb ai/A/application (total rate of 8.8 lb ai/A) for broccoli,
Brussels sprouts, and cauliflower; and (ii) a maximum of 9 applications
per season at 1.2 lb ai/A/application (total rate of 10.8 lb ai/A) for
cabbage.   

Conclusions.  The available residue data for broccoli, Brussels sprouts,
cabbage, and cauliflower are adequate to support the proposed crop
subgroup tolerance of 5.0 ppm for head and stem Brassica, subgroup 5A,
pending the submission of a revised Section B to specify a maximum
seasonal rate of 8.8 lb ai/A.  Alternatively, the petitioner may submit
crop field trial data for the representative commodities of the head and
stem Brassica subgroup reflecting application at the maximum seasonal
rate of 12 lb ai/A.  

Legume Vegetable (group 6)

Lentil

No residue data were submitted in support the proposed use on lentil. 
The petitioner has proposed to translate data for chlorothalonil on dry
bean to lentil.  Typically, HED allows translation of data for dry pea
to Lens culinaris (lentils), as per 40 CFR §180.1(g), if the registered
uses for the two crops are identical.  There are currently no registered
uses of chlorothalonil on dry pea.  However, because the proposed use on
lentil is identical to the existing use on dry bean (maximum seasonal
rate of 6.0 lb ai/A with a 14-day PHI), and lentil and dry bean are
similar crops with similar growing areas, HED will allow translation of
data in this case.  The tolerance for combined residues of
chlorothalonil and SDS-3701 in/on lentil should be established at the
same level as the dry bean seed tolerance, 0.10 ppm. 

Lupin

No residue data were submitted in support the proposed use on lupin. 
The petitioner has proposed to translate data for chlorothalonil on dry
bean to lupin.    SEQ CHAPTER \h \r 1 HED allows translation of data
from dry bean to Lupinus spp. (including sweet lupine, white sweet
lupine, white lupine, and grain lupine) as per 40 CFR §180.1(g) if the
registered/proposed uses for the two crops are identical.  In fact, uses
on lupin are on the current product label for the 6 lb/gal FlC
formulation, as part of the use directions for dry beans.  Since the
proposed use on lupin is identical to the recommended label amendments
made in the 6/13/95 Residue Chemistry Chapter (maximum seasonal rate of
6.0 lb ai/A with a 14-day PHI), the available dry bean field trial data
may be translated to lupin.  The established dry bean tolerance will
cover the proposed lupin use; there is no need to establish a separate
tolerance on lupin.  

  

Fruiting Vegetable (group 8)

DER Reference:	47248501.der.doc (Bell pepper)

		47248502.der.doc (Non-bell pepper)

Residue Chemistry Chapter of the HED Chapter of the RED, DP# 201522,
6/13/95, W. Smith

An individual tolerance for the combined residues of chlorothalonil and
its 4-hydroxy metabolite in/on tomato has been established at 5 ppm [40
CFR §180.275(a)(1)].  In addition, a tolerance for the combined
residues of chlorothalonil and its metabolites in/on imported non-bell
pepper has been established at 5 ppm [40 CFR §180.275(a)(1)].  In
support of proposed uses of chlorothalonil on the fruiting vegetable
group, IR-4 has submitted field trial data for pepper (bell and
non-bell) and has proposed to convert the individual tolerance for
tomato to a crop group 8 tolerance at the same level.  The
representative commodities of the fruiting vegetable group are tomato,
bell pepper, and non-bell pepper.

Pepper, bell

IR-4 has submitted field trial data for chlorothalonil on bell peppers. 
Nine field trials were conducted in the U.S. in Zones 2 (GA, NJ, and SC;
3 trials), 3 (FL; 2 trials), 5 (OH; 1 trial), 6 (TX; 1 trial), and 10
(CA; 2 trials) during the 1997 and 1998 growing seasons.  At each trial
site, the treated plot received seven or eight foliar applications of a
6 lb/gal FlC formulation of chlorothalonil at a target rate of 1.125 lb
ai/A/application for a total seasonal rate of ~8-9 lb ai/A (~1x the
proposed maximum seasonal rate).  At four of the trial sites,
applications were made as foliar broadcast sprays and at the other five
sites, applications were made as foliar directed sprays.  Applications
were made in 30-94 gal/A spray volumes without an adjuvant; RTIs were 6
to 10 days.  At one site (GA), extremely hot weather caused a decreased
fruit set, resulting in seven rather than eight applications to the
plants.

Mature bell peppers were harvested 2-3 days after the last application. 
Additional bell pepper samples were collected from four trials 6/7,
13/14, and 27-29 days after the last application to generate residue
decline data.  Also, additional samples were collected 2-3 days after
the final application from five trials to evaluate the effects of
refrigeration and rinsing before frozen storage on residues.  Two sets
of additional samples were collected; for one set, the pepper samples
were refrigerated for 3-4 days and then immediately placed in frozen
storage, and for the second set, the pepper samples were refrigerated
for 3-4 days and then rinsed with water before frozen storage.

Samples of bell pepper were analyzed for residues of chlorothalonil and
SDS-3701 using an adequate GC/ECD method.  The validated LOQ was 0.030
ppm for chlorothalonil and SDS-3701.  Sample storage condition and
durations are reported in Table 4.  Adequate storage stability data are
available to support sample storage durations and conditions.  

The results of the bell pepper field trials are summarized in Table 5.4.
 Maximum combined residues of chlorothalonil and SDS-3701 were <3.53 ppm
in/on bell peppers harvested 2-3 days after the final application of
chlorothalonil.  Maximum individual residues of chlorothalonil were 3.5
ppm.  Residues of SDS-3701 were below the LOQ in/on all samples.

For samples refrigerated for 3-4 days prior to being frozen, the maximum
combined residues of chlorothalonil and SDS-3701 were <2.73 ppm.  For
samples refrigerated for 3-4 days and then rinsed with water prior to
being frozen, the maximum combined residues were <0.90 ppm.  The results
indicate that three days of refrigeration does not reduce residues,
however, a water rinse of samples does appear to reduce residues.  

The submitted residue decline data indicated that residues of
chlorothalonil generally declined in bell peppers with increasing
harvest intervals.  Because residues of SDS-3701 were <LOQ in/on all
samples, residue decline could not be assessed.

Pepper, non-bell

IR-4 has submitted field trial data for chlorothalonil on non-bell
peppers.  Six field trials were conducted in the U.S. in Zones 2 (NJ; 1
trial), 3 (FL; 1 trial), 5 (OH; 1 trial), 6 (TX; 2 trials), and 10 (CA;
1 trial) during the 1999 growing season.  At five of the trial sites,
the treated plot received eight foliar applications of a 82.5% WDG
formulation of chlorothalonil at a target rate of 1.125 lb
ai/A/application for a total seasonal rate of ~9.0 lb ai/A. 
Applications were made as foliar directed sprays at four of the sites
and as foliar broadcast sprays at one of the trial sites.  At the sixth
trial site (CA), the treated plot received six foliar directed
applications to shorten the application period; applications 1, 2, 4, 5,
and 6 were each made at ~1.125 lb ai/A and application 3 was made at
3.359 lb ai/A, for a total seasonal rate of 9.0 lb ai/A.  The
application rates are 1x the proposed maximum seasonal rate for the FlC
formulation; the petitioner has not proposed use of the WDG formulation
on fruiting vegetables.  Applications were made in 30-62 gal/A spray
volumes without an adjuvant; RTIs were 4 to 9 days.

Mature peppers were harvested 2-3 days after the last application. 
Additional pepper samples were collected from three trials 2/3, 7/8, and
13/14 days after the last application to generate residue decline data. 


Samples of non-bell pepper were analyzed for residues of chlorothalonil
and SDS-3701 using an adequate GC/ECD method.  The validated LOQ was
0.030 ppm for chlorothalonil and SDS-3701.  Sample storage conditions
and durations are reported in Table 4.  Adequate storage stability data
are available to support sample storage durations and conditions.

The results of the non-bell pepper field trials are summarized in Table
5.4.  Maximum combined residues of chlorothalonil and SDS-3701 were
<1.83 ppm in/on non-bell peppers harvested 2-3 days after the final
application of chlorothalonil.  Maximum individual residues of
chlorothalonil were 1.8 ppm.  Residues of SDS-3701 were <LOQ in/on all
samples.

The submitted residue decline data indicated that residues of
chlorothalonil do not increase in/on non-bell peppers with increasing
harvest intervals.  In one of the decline trials, chlorothalonil
residues remained approximately the same at the 2- and 14-day sampling
intervals.  In the other two decline trials, chlorothalonil residues
decreased with increasing sampling intervals.  Because residues of
SDS-3701 were <LOQ in/on all samples, residue decline could not be
assessed.  

Table 5.4.  Summary of Residue Data from Pepper Field Trials with
Chlorothalonil.

Crop matrix	EP1	Total Applic. Rate (lb ai/A)	PHI (days)	Combined Residue
Levels (ppm)2





n	Min.	Max.	HAFT3	Median	Mean	Std. Dev.

Fruiting vegetables, group 8 and Okra (proposed use = 9 lb ai/A total
application rate, 3-day PHI)

Pepper, bell	6 lb/gal FlC	8.1-9.2	2-3	18	<0.36	<3.53	<2.93	1.48	1.48
0.93

Pepper, non-bell	82.5% WDG	9.0-9.2	2-3	12	<0.46	<1.83	<1.63	0.81	1.03
0.48

1  EP = End-use Product.

2  Combined Residues = chlorothalonil + SDS-3701.

3  HAFT = Highest-average field trial result.

Tomato

No tomato residue data were submitted with this petition.  Currently,
the 6 lb/gal FlC formulation is registered for multiple foliar
applications to tomatoes at up to 2.1 lb ai/A/application, with a
maximum seasonal rate of 15 lb ai/A and a 0-day PHI.  IR-4 has proposed
application of the 6 lb/gal FlC formulation to fruiting vegetables at
the maximum seasonal rate of 9 lb ai/A with a 3-day PHI.  The proposed
use is more restrictive than the registered use on tomatoes.

The 6/13/95 Residue Chemistry Chapter concluded that   SEQ CHAPTER \h \r
1   SEQ CHAPTER \h \r 1   SEQ CHAPTER \h \r 1 adequate field trial data
were available supporting the use of chlorothalonil on tomato, provided
the registrant amended all pertinent product labels to specify a maximum
number of applications or a maximum seasonal rate; the available data
support a maximum of 11 applications per season at 2.3 lb
ai/A/application (total rate of 25.3 lb ai/A) for tomato.  The
established 5-ppm tolerance for the combined residues of chlorothalonil
and its 4-hydroxy metabolite in/on tomato is supported by these data.   

Conclusions.  The submitted residue data for bell and non-bell peppers,
representative commodities of fruiting vegetables crop group (group 8),
are not adequate to fulfill data requirements.  For bell peppers, the
number and location of bell pepper crop field trials are accordance with
OPPTS Guideline 860.1500, and the trials reflect the proposed use
pattern.  For non-bell peppers, although the petitioner conducted more
than the required number of field trials (only three trials are
required), no trials were conducted in Zone 8, which represented 50% of
non-bell pepper production (860.1500, Table 6).  In addition, the
non-bell pepper trials were conducted using a WDG formulation and the
petitioner has proposed use of an FlC formulation on non-bell peppers. 
HED does not generally allow translation of residue data between FlC and
WDG formulations for use patterns reflecting late-season applications.  

To support use of the FlC formulation on non-bell peppers, the
petitioner should conduct one additional side-by-side field trial with
non-bell peppers.  The trial should reflect side-by-side plots receiving
applications of the FlC and WDG formulations at 1x the proposed maximum
seasonal rate, and the trial should be conducted in Zone 8.  If the
trial indicates that residues in/on samples treated with the FlC
formulation are higher than in/on samples treated with the WDG
formulation, two additional field trials will be required, so that a
total of three field trials are available reflecting application of the
FlC formulation to non-bell peppers.  HED will consider submission of
these data to be a condition of registration.

The available data indicate that combined residues of chlorothalonil and
SDS-3701 will not exceed the proposed 5-ppm tolerance in/on the
representative commodities of the fruiting vegetable crop group. 
However, since the use directions for tomatoes and the other fruiting
vegetables differ significantly, separate tolerances should be
established for “tomato” and “vegetable, fruiting, group 8, except
tomato.”  The recommended tolerance for vegetable, fruiting, group 8,
except tomato is 6.0 ppm, based on residue data from bell pepper.  

Okra

No okra residue data were submitted in support the proposed use on okra.
 IR-4 has proposed to translate the existing and submitted fruiting
vegetable data (peppers and tomatoes) to okra.  The proposed use on okra
is identical to the proposed use on the fruiting vegetables crop group. 
HED has approved adding okra to the fruiting vegetable crop group (see
minutes of ChemSAC meeting of 10/18/06).  Until 40 CFR §180.41 is
updated, a separate tolerance should be established for okra.  

Conclusions.  The available data for the fruiting vegetable crop group
may used to support the proposed tolerance for okra.  The tolerance
should be established at the same level as the fruiting vegetable group,
except tomato tolerance, 6.0 ppm.

Cucurbit Vegetable (group 9)

Residue Chemistry Chapter of the HED Chapter of the RED, DP# 201522,
6/13/95, W. Smith

No new cucurbit vegetable residue data were submitted.  Individual
tolerances for the combined residues of chlorothalonil and its 4-hydroxy
metabolite in/on cucumber, melon, pumpkin, summer squash, and winter
squash have been established, each at 5 ppm [40 CFR §180.275(a)(1)]. 
IR-4 has proposed to convert these individual tolerances for cucumber,
melon, pumpkin, summer squash, and winter squash to a crop group 9
tolerance at the same level.  The representative crops of the cucurbit
vegetable group are cucumber, muskmelon, and summer squash.

Currently, the 6 lb/gal FlC formulation is registered for multiple
foliar applications to cucurbits (defined as cucumber, cantaloupe,
muskmelon, honeydew, watermelon, squash, and pumpkin) at up to 2.25 lb
ai/A/application, with a maximum seasonal rate of 15.75 lb ai/A and a
0-day PHI.  IR-4 has proposed application of the 6 lb/gal FlC
formulation to cucurbit vegetables at a maximum seasonal rate of 15.8 lb
ai/A with a 0-day PHI.  The proposed use is identical to the registered
use on cucurbits.

The 6/13/95 Residue Chemistry Chapter concluded that   SEQ CHAPTER \h \r
1   SEQ CHAPTER \h \r 1   SEQ CHAPTER \h \r 1 adequate field trial data
were available supporting the use of chlorothalonil on cucumber, melon,
pumpkin, summer squash, and winter squash according the following uses: 
(i) a seasonal application schedule of one application at vine formation
at up to 6.3 lb ai/A plus 9 applications at 2.3 lb ai/A/application
(total rate of 27 lb ai/A) for cucumber; and (ii) a maximum of 10
applications per season at 2.2 lb ai/A/application (total rate of 22 lb
ai/A) for melon, pumpkin, and squash (summer and winter). 

Conclusions.  The available residue data for cucumber, melon, pumpkin,
summer squash, and winter squash are adequate to support the proposed
crop group tolerance of 5.0 ppm for cucurbit vegetables, group 9.  

Miscellaneous Commodities

Persimmon

DER Reference:	47248503.der.doc

IR-4 has submitted field trial data for chlorothalonil on persimmon. 
Two field trials were conducted in the U.S. in Zones 3 (FL) and 13 (HI)
during the 1996 growing season.  At each trial site, the treated plot
received five foliar spray applications of a 6 lb/gal FlC formulation of
chlorothalonil at a rate of 1.0 lb ai/A/application, for a total
seasonal rate of 5.0 lb ai/A (~1x the proposed maximum seasonal rate). 
The first two applications and the last three applications were made at
13- to 14-day RTIs; the interval between the second and third
applications was 82-86 days.  All applications were made in 36-100 gal/A
spray volumes without an adjuvant.  Mature persimmons were harvested 14
and 28 days after the last application; a single sample was collected
from each plot.  

Samples were analyzed for residues of chlorothalonil and SDS-3701 using
an adequate GC/ECD method.  The validated LOQ was 0.10 ppm for
chlorothalonil, SDS-3701.  The method was adequate for data collection
for chlorothalonil and SDS-3701 based on acceptable concurrent recovery
data.  Sample storage conditions and durations are reported in Table 4. 
Adequate storage stability data are available to support sample storage
durations and conditions.

The results of the persimmon field trials are summarized in Table 5.5. 
Maximum combined residues of chlorothalonil and SDS-3701 were <1.15 ppm
and <0.650 ppm in/on persimmon harvested 14 and 28 days, respectively,
after the final application of chlorothalonil.  Maximum individual
residues of chlorothalonil were 1.05 ppm and 0.550 ppm for the 14-day
and 28-day PHI, respectively.  Residues of SDS-3701 were <LOQ in/on all
samples from both sampling intervals.  

Table 5.5.	Summary of Residue Data from Persimmon Field Trials with
Chlorothalonil.

Crop matrix	Total Applic. Rate (lb ai/A)	PHI (days)	Combined Residue
Levels (ppm)1



	n	Min.	Max.	HAFT2	Median	Mean	Std. Dev.

Persimmon (proposed use = 4.7 lb ai/A total application rate, 14-day
PHI)

Persimmon	5.0	14	4	<0.525	<1.15	<1.14	0.979	0.908	0.292



28	4	<0.20	<0.650	<0.508	0.489	0.457	0.213

1  Combined Residues = chlorothalonil + SDS-3701.

2  HAFT = Highest-average field trial result.

Conclusions.  The submitted residue data for persimmon are inadequate to
support the proposed use.  The number and locations of field trials are
not in accordance with OPPTS Guideline 860.1500 for persimmon. 
According to OPPTS 860.1500, Table 1, for persimmon, the petitioner has
the option of conducting 3 trials with two treated samples (1x rate) per
trial or 2 trials with four treated samples (two at 1x rate, two at 2x
rate) per trial.  In this study, IR-4 submitted 2 trials at ~1x proposed
rate collecting four treated samples (two at the proposed PHI of 14 days
and two at a 28-day PHI).  The trials generally reflected the proposed
use pattern; however, the proposed RTI of 10 days is not supported by
the submitted data.

The trials were conducted in Zone 3 and 13, which represent only 3% of
persimmon production (Table 6 of OPPTS 860.1500).  However, the
petitioner stated that the proposed use on persimmon was requested on
behalf of the states of FL (Zone 3) and HI (Zone 13).  

If the petitioner modifies the proposed use to specify that
chlorothalonil may only be used on persimmon grown in Florida and Hawaii
and to specify that the minimum RTI is 14 days, no additional crop field
trial data for persimmon will be required.  The available data would
support establishment of a tolerance with regional registration for the
combined residues of chlorothalonil and SDS-3701 in/on persimmon at 1.5
ppm.

If the petitioner wishes to support use of chlorothalonil on persimmon
without regional registration, two additional crop field trials will be
required, conducted in Zone 10.  The trials should be conducted
according to the maximum proposed use pattern for persimmon.

Lychee and Starfruit

RD has also requested that HED recommend levels for tolerances on lychee
and starfruit in order to alleviate trade irritant issues with the
government of Taiwan.  Based on translation from existing tolerances on
tropical fruits, HED is recommending for tolerances of 15 ppm for lychee
(translated from papaya) and 3 ppm for starfruit (translated from
passionfruit; personal communication from B. Schneider, 7/16/08).  

860.1520 Processed Food and Feed

Residue Chemistry Chapter of the HED Chapter of the RED, DP# 201522,
6/13/95, W. Smith

Tomato is only crop associated with this petition for which HED requires
residue data for processed fractions.  Adequate processing data are
available supporting the use of chlorothalonil on tomato.  No tolerances
are required for processed tomato fractions (paste and puree).

  SEQ CHAPTER \h \r 1 860.1650 Submittal of Analytical Reference
Standards

Analytical standards for chlorothalonil and 4-hydroxy chlorothalonil are
currently available in the EPA National Pesticide Standards Repository
(personal communication with Dallas Wright, ACB, 1/2/08), with
expiration dates of 9/1/08 for chlorothalonil and 1/31/08 for 4-hydroxy
chlorothalonil.  Because the standard for 4-hydroxy chlorothalonil has
expired, the registrant should either recertify the lot in the
repository and send in an updated COA, or submit a new standard
(different lot #) if the previous lot will not be recertified.  If a new
COA is being submitted, it should be faxed to the repository at
410-305-2999.

If a new standard is being submitted, it should be sent to the
Analytical Chemistry Lab, which is located at Fort Meade, to the
attention of Theresa Cole at the following address:

	USEPA

	National Pesticide Standards Repository/Analytical Chemistry Branch/OPP

	701 Mapes Road

	Fort George G. Meade, MD  20755-5350

(Note that the mail will be returned if the extended zip code is not
used.)

860.1850 and 1900 Confined and Field Accumulation in Rotational Crops

Residue Chemistry Chapter of the HED Chapter of the RED, DP# 201522,
6/13/95, W. Smith

Adequate data pertaining to rotational crops are available.  In response
to an Agency evaluation of confined rotational crop data, the registrant
submitted several rotational crop studies.  These data indicated that
the only residue that was detected in rotated crops was the soil
metabolite SDS-46851 (3-carbamyl-2,4,5-trichlorobenzoic acid).  Because
of the low toxicity of this metabolite, an exemption for the requirement
of a tolerance has been established for residues of SDS-46851 as
inadvertent residues in rotated crops (40 CFR §180.1110).  In addition,
the registrant’s request to delete rotational crop restrictions from
chlorothalonil labels was approved.  Because the proposed uses do not
include a maximum seasonal rate greater than the registered maximum
seasonal rate to annual crops, no additional rotational crop data are
needed to support the proposed uses.

860.1550 Proposed Tolerances

HED has determined that the residues of concern in plant commodities are
chlorothalonil (tetrachloroisophthalonitrile) and its metabolite
4-hydroxy-2,5,6-trichloroisophthalonitrile.  The tolerance expression
proposed in this petition is appropriate.

The tolerances proposed by the petitioner in the current petition are
listed below in Table 6, along with the recommended tolerance levels.   
SEQ CHAPTER \h \r 1 The petitioner should submit a revised section F
reflecting the revised tolerances and commodity definitions presented in
Table 6.

Adequate field trial data are available for cucurbit vegetables (group
9), ginseng, horseradish, lentil, okra, rhubarb, and yam.  Provided the
proposed uses are amended as requested, adequate field trial data are
available for Brassica head and stem vegetables (subgroup 5A) and
persimmon.  Additional field trial data are required for fruiting
vegetables (group 8); however, HED recommends for conditional
registration of chlorothalonil on this group while the data are
generated.  

HED’s Guidance for Setting Pesticide Tolerances Based on Field Trial
Data was utilized for determining appropriate tolerance levels for
ginseng, horseradish, and rhubarb; see Appendix I for tolerance
calculations.  The available data indicate that the proposed tolerance
for horseradish is adequate but the proposed tolerance for ginseng is
too low and the proposed tolerance for rhubarb is too high.  Tolerances
of 4.0 ppm would be appropriate for both ginseng and rhubarb. 
Concomitant with the establishment of the permanent tolerance for
ginseng, the established time-limited tolerance for ginseng should be
removed.  

The tolerance spreadsheet was not used to determine the appropriate
tolerance level for persimmon because only four residue values are
available for persimmon.  The tolerance was set at 1.5 ppm based on
maximum combined residues of <1.15 ppm.  

The submitted data for bell and non-bell pepper indicate that the
proposed use of chlorothalonil will not result in combined residues of
chlorothalonil and SDS-3701 greater than the existing tolerance of 5 ppm
for tomato.  However, since the use directions for tomatoes and the
other fruiting vegetables differ significantly, separate tolerances
should be established for “tomato” and “vegetable, fruiting, group
8, except tomato.”  The available bell pepper data indicate that a
tolerance of 6.0 ppm is appropriate for vegetable, fruiting, group 8,
except tomato.

The available field trial data for the fruiting vegetables crop group
may be translated to support use on okra.  These data support the
proposed tolerance of 6.0 ppm for okra.  

Currently, individual tolerances exist for combined residues of
chlorothalonil and SDS-3701 in/on broccoli, Brussels sprouts, cabbage,
and cauliflower, each at 5 ppm.  Pending submission of a revised Section
B, the available residue data support a subgroup tolerance for head and
stem Brassica vegetables at 5.0 ppm.  Concomitant with the establishment
of the subgroup tolerance for head and stem Brassica, the established
individual tolerances for broccoli, Brussels sprouts, cabbage, and
cauliflower should be removed.

Currently, individual tolerances exist for combined residues of
chlorothalonil and SDS-3701 in/on cucumber, melon, pumpkin, and squash
(summer and winter), each at 5.0 ppm.  The available residue data
support a group tolerance for cucurbit vegetables at 5.0 ppm. 
Concomitant with the establishment of the group tolerance for cucurbit
vegetables, the established individual tolerances for cucumber, melon,
pumpkin, summer squash, and winter squash should be removed.

The proposed tolerances for lentil and yam are supported by translation
of residue data from dry bean and potato, respectively.  The proposed
tolerance for yam is too high; however, the proposed tolerance of 5.0
ppm listed in Section F of the petition appears to be a typographical
error, as the text portion of the petition document indicates that IR-4
is requesting at 0.1-ppm tolerance.  

The requested tolerance for lupin is not needed as the existing
tolerance for dry bean is adequate to support lupin (see 40 CFR
§180.1g).  

The available processing data indicate that no tolerances are needed for
tomato processed commodities. 

The Codex Alimentarius Commission has established MRLs for
chlorothalonil per se at 7 ppm for sweet pepper; 5 ppm each for
broccoli, Brussels sprouts, cucumber, tomato, and squash (summer and
winter); 2 ppm for melons (except watermelon); 1 ppm each for cabbage,
heads and cauliflower; and 0.2 ppm for dry beans.  Mexican MRLs for
“clorotalonil” have been established at 0.1 ppm for bean and 5 ppm
each for broccoli, Brussels sprouts, cabbage, cauliflower, cucumber,
melon, squash, and tomato.  As the U.S. tolerance definition differs
from the Codex and Mexican definitions, harmonization is not possible. 
Canadian MRLs for chlorothalonil and its 4-hydroxy metabolite are
established at 5 ppm each for beans, broccoli, Brussels sprouts,
cabbage, cauliflower, cucumber, melons, pumpkins, squash, and tomatoes. 
With the exception of beans (which presumably includes dried beans), the
Canadian MRLs are harmonized with U.S. tolerances.  An International
Residue Limit form is included as an attachment to this document.

Table 6.  Tolerance Summary for Chlorothalonil.

Commodity	Established Tolerance (ppm)1	Proposed Tolerance (ppm)
Recommended Tolerance (ppm)	Comments; Correct Commodity Definition

Brassica, head and stem, subgroup 5A	--	5.0	5.0	Tolerance recommendation
is based on residue data translated from broccoli, Brussels sprouts,
cabbage, and cauliflower and pending label revision to specify a 7-day
PHI and a maximum seasonal rate of 8.8 lb ai/A.

Broccoli	5	--	Remove from 180.275(a)(1)	Covered by tolerance for
Brassica head and stem subgroup.

Brussels sprouts	5	--



Cabbage	5	--



Cauliflower	5	--



Cucumber	5	--	Remove from 180.275(a)(1)	Covered by tolerance for
cucurbit vegetable group.

Ginseng	0.102	3.0	4.0	Established tolerance under 180.275(b) should be
removed when 4.0-ppm tolerance is established under 180.275(a)(1).

Horseradish	--	4.0	4.0

	Lentil	--	0.1	0.10	Tolerance recommendation based on residue data
translated from dry bean seed.

Lupin	--	0.1	None	Covered by the established tolerance for dry bean
seed. 

Melon	5	--	Remove from 180.275(a)(1)	Covered by tolerance for cucurbit
vegetable group.

Okra	--	5.0	6.0	Tolerance recommendation based on residue data for
representative crops of fruiting vegetables crop group.

Persimmon	--	1.9	1.5	Tolerance should be established under 40 CFR
§180.275(c) and proposed use should be amended to restrict use to FL
and HI.

Pepper, non-bell	53	--	Remove from 180.275(a)(1)	Covered by tolerance
for fruiting vegetable crop group.

Pumpkin	5	--	Remove from 180.275(a)(1)	Covered by tolerance for cucurbit
vegetable group.

Rhubarb	--	5.0	4.0

	Squash, summer	5	--	Remove from 180.275(a)(1)	Covered by tolerance for
cucurbit vegetable group.

Squash, winter	5	--



Tomato	5

5.0

	Vegetable, cucurbit, group 9	--	5.0	5.0	Tolerance recommendation is
based on residue data for cucumber, melon, summer squash, and winter
squash.

Vegetables, fruiting, group 8	--	5.0	6.0	Tolerance recommendation is
based on residue data for bell pepper.

Vegetable, fruiting, group 8, except tomato.

Yam	--	5.0	0.10	Tolerance recommendation is based on residue data
translated from potato.

Lychee 	--	--	15	Recommended at the request of RD.

Starfruit	--	--	3.0

	1  Established under 40 CFR §180.275(a)(1) unless otherwise specified.

2  Established under 40 CFR §180.275(b). 

3  No U.S. registrations as of January 2001.

References

DP#:	Not applicable

Subject:	PP#0E3889: Chlorothalonil (Daconil®, Bravo®) in or on
Blueberries. Evaluation of Analytical Methods and Residue Data; CBTS
#7029

From:	W.T. Chin

To:	J. Miller and Toxicology Branch

Dated:	2/22/91

MRIDs:	41614900 and 41614901

DP#:	201522

Subject:	Chlorothalonil: List A Reregistration Case No. 0097: Chemical
ID No. 081901:  Product and Residue Chemistry Considerations to be
Included in the HED Chapter of the Reregistration Eligibility Decision
Document.  CBRS No. 13505

From:	W. Smith

To:	K. Whitby

Dated:	6/13/95

MRIDs:	None

  SEQ CHAPTER \h \r 1 DP#s:	213088, 213193, 213196, 213200

Subject:	Chlorothalonil:  Case No. 0097:  Chemical No. 081901:  Amended
Directions for Use on Potatoes:  CBRS No. 15274  

From:	W. Smith

To:	C. Giles-Parker/J. Stone

Dated:	8/9/95

MRIDs:	None

  SEQ CHAPTER \h \r 1 DP#:	220825

Subject:	Chlorothalonil:  PP#6F4611; Reregistration Case No. 0097;
Chemical No. 081901.  CBRS No. 16482.

From:	W. Smith

To:	R. Kearns/C. Giles-Parker and A. Ertman/W. Waldrop

Dated:	3/5/96

MRIDs:	43832401-43832404

  SEQ CHAPTER \h \r 1 DP#:	228522

Subject:	Chlorothalonil: Reregistration Case No. 0097: Chemical No.
08190: Comments from ISK Biosciences on the Chlorothalonil HED RED
Chapter: No MRID No: CBRS No. 17447

From:	W. Smith

To:	T. Myers

Dated:	10/08/96

MRIDs:	none

  SEQ CHAPTER \h \r 1 DP#:	235069

Subject:	Chlorothalonil Reregistration:  List A Case No. 0097:  Chemical
No. 081901:  ISK-Bioscience’s Submission of Final Report on 6-year
Storage Stability Study.  

From:	W. Smith

To:	M. Clock

Dated:	6/30/97

MRIDs:	44240501-44240510

  SEQ CHAPTER \h \r 1 Attachments:  

International Residue Limit Status sheet

Appendix I - Tolerance Assessment Calculations

cc:  G. Kramer (RAB1)

RDI:  RAB1 Chemists (4/23/08)

G.F. Kramer:S10781:PY-S:(703)305-5079:7509P:RAB1

Template Version September 2005



INTERNATIONAL RESIDUE LIMIT STATUS

Chemical Name:  2,4,5,6-tetrachloro-1,3-benzenedicarbonitrile	Common
Name:

Chlorothalonil	X Proposed tolerance

( Reevaluated tolerance

( Other	Date: 12/27/07

Codex Status (Maximum Residue Limits)	U. S. Tolerances

( No Codex proposal step 6 or above

( No Codex proposal step 6 or above for the crops requested	Petition
Number:  PP#7E7270

DP#:  346319

Other Identifier:  Decision Number 385118

Residue definition (step 8/CXL): Chlorothalonil	Reviewer/Branch:  G.
Kramer/RAB1

	Residue definition:  Chlorothalonil and its metabolite
4-hydroxy-2,5,6-trichloroisophthalonitrile

Crop (s)	MRL (mg/kg)	Crop(s) 	Tolerance (ppm)

Peppers, Sweet	7	Vegetables, fruiting, group 8	5.0

Tomato	5



Cucumber	5	Vegetable, cucurbit, group 9	5.0

Melons, except watermelon	2



Squash  (summer)	5



Squash, winter	5





Okra	5.0



Persimmon	1.9



Horseradish	4.0



Rhubarb	5.0



Ginseng	3.0



Yam	5.0

Beans (dry)	0.2	Lupin	0.1



Lentil	0.1

Broccoli	5	Brassica, head and stem, subgroup 5A	5.0

Brussels sprouts	5



Cabbages, Head	1



Cauliflower	1



Limits for Canada	Limits for Mexico

( No Limits

( No Limits for the crops requested	( No Limits

( No Limits for the crops requested

Residue definition:  tetrachloroisophthalonitrile, including the
metabolite 4-hydroxy-2,5,6-trichloro-1,3-benzenedicarbonitrile	Residue
definition:  Clorotalonil

Crop(s)	MRL (mg/kg)	Crop(s)	MRL (mg/kg)

Beans	5	Bean	0.1

Broccoli, Brussels sprouts, cabbage, cauliflower	5	Broccoli	5



Brussels sprouts	5



Cabbage	5



Cauliflower	5

Cucumbers, melons, pumpkins, squash	5	Cucumber	5



Melon	5



Squash	5

Tomatoes	5	Tomato	5

Notes/Special Instructions:  S.Funk, 01/02/2008.



Appendix I.  Tolerance Assessment Calculations.

For each of the crops listed below, the Guidance for Setting Pesticide
Tolerances Based on Field Trial Data (SOP), along with the tolerance
spreadsheet (January 2008 version), was used for calculating recommended
tolerances.  As specified in the SOP, the minimum of the 95%
upper-confidence limit (UCL) on the 95th percentile and the point
estimate of the 99th percentile was selected as the tolerance value in
cases when the dataset was large (greater than 15 samples) and
reasonably lognormal.  For datasets that were small (≤15 samples) and
reasonably lognormal, the upper bound estimate of the 95th percentile
based on the median residue value was compared to the minimum of the 95%
UCL on the 95th percentile and the point estimate of the 99th
percentile, and the minimum value was selected as the tolerance value. 
The rounding procedures specified in the SOP were also used.

Ginseng

The dataset used to establish a tolerance for chlorothalonil on ginseng
consisted of field trial data representing application rates of
12.2-12.5 lb ai/A (8 applications at 1.4-1.6 lb ai/A/application) with a
6- to 8-day PHI.  The field trial application rates are within 25% of
the maximum label application rate; however, the PHIs are less than the
proposed PHI of 14 days.  The petitioner did not address the issue of
the shorter PHIs in the field trials.  The residue values that were
entered into the tolerance spreadsheet are provided in Table I-1; the
residue values have been corrected for potential decline of
chlorothalonil residues during storage.

All field trial sample results for chlorothalonil and SDS-3701 in/on
ginseng were above the LOQ (validated LOQ = 0.02 ppm for chlorothalonil
and 0.2 ppm for SDS-3701), with the exception of one sample in which
residues of SDS-3701 were <0.2 ppm.  The ginseng dataset was small (6
samples).  Visual inspection of the lognormal probability plot (Figure
I-1) and the results from the approximate Shapiro-Francia test statistic
(Figure I-2) indicated that ginseng dataset was reasonably lognormal.  

Using the tolerance spreadsheet, the recommended tolerance is 4.0 ppm
for ginseng. 

Table I-1.	Residue data used to calculate tolerance for combined
residues of chlorothalonil and SDS-3701 on ginseng.

Regulator:	EPA

Chemical:	Chlorothalonil

Crop:	Ginseng (corrected for decline in storage)

PHI:	6-8 Days

App. Rate:	12.2-12.5 lb ai/A

Submitter:	IR-4

MRID Citation:	MRID 47248506

	Combined Residues of Chlorothalonil and SDS-3701 (ppm)

	0.88

	0.88

	1.39

	2.43

	0.52

	0.53



Figure I-1.  Lognormal probability plot of chlorothalonil field trial
data for ginseng.

 

Figure I-2.  Tolerance spreadsheet summary of chlorothalonil field trial
data for ginseng.

 

Horseradish

The dataset used to establish a tolerance for chlorothalonil on
horseradish consisted of field trial data representing application rates
of 17.8-18.2 lb ai/A (8 applications at 2.15-2.34 lb ai/A/application)
with a 12- to 15-day PHI.  As specified by the SOP, the field trial
application rates and PHIs are within 25% of the maximum label
application rate and minimum label PHI, respectively.  The residue
values that were entered into the tolerance spreadsheet are provided in
Table I-2.

All field trial sample results for chlorothalonil and SDS-3701 in/on
horseradish were above the LOQ (validated LOQ = 0.02 ppm for
chlorothalonil and SDS-3701), with the exception of one sample in which
residues of chlorothalonil were <0.02 ppm.  The horseradish dataset was
small (6 samples).  Visual inspection of the lognormal probability plot
(Figure I-3) and the results from the approximate Shapiro-Francia test
statistic (Figure I-4) indicated that the horseradish dataset was
reasonably lognormal.  

Using the tolerance spreadsheet, the recommended tolerance is 4.0 ppm
for horseradish root.

Table I-2.	Residue data used to calculate tolerance for combined
residues of chlorothalonil and SDS-3701 on horseradish.

Regulator:	EPA

Chemical:	Chlorothalonil

Crop:	Horseradish

PHI:	12-15 Days

App. Rate:	17.8-18.2 lb ai/A

Submitter:	IR-4

MRID Citation:	MRID 47248504

	Combined Residues of Chlorothalonil and SDS-3701(ppm)

	0.073

	<0.045

	0.54

	0.51

	0.42

	0.63



Figure I-3.  Lognormal probability plot of chlorothalonil field trial
data for horseradish.

Figure I-4.  Tolerance spreadsheet summary of chlorothalonil field trial
data for horseradish.

Rhubarb

The dataset used to establish a tolerance for chlorothalonil on rhubarb
consisted of field trial data representing application rates of
13.5-14.5 lb ai/A (6 applications at 2.22-2.46 lb ai/A/application) with
a 27- to 34-day PHI.  As specified by the SOP, the field trial
application rates and PHIs are within 25% of the maximum label
application rate and minimum label PHI, respectively.  The residue
values that were entered into the tolerance spreadsheet are provided in
Table I-3.

Residues of chlorothalonil were above the LOQ in/on all rhubarb samples
while residues of SDS-3701 were below the LOQ in/on all samples
(validated LOQ = 0.02 ppm for chlorothalonil and SDS-3701).  The rhubarb
dataset was small (8 samples).  Visual inspection of the lognormal
probability plot (Figure I-5) and the results from the approximate
Shapiro-Francia test statistic (Figure I-6) indicated that the rhubarb
dataset was reasonably lognormal.  

Using the tolerance spreadsheet, the recommended tolerance is 4.0 ppm
for rhubarb.

Table I-3.	Residue data used to calculate tolerance for combined
residues of chlorothalonil and SDS-3701 on rhubarb.

Regulator:	EPA

Chemical:	Chlorothalonil

Crop:	Rhubarb

PHI:	27-34 Days

App. Rate:	13.5-14.5 lb ai/A

Submitter:	IR-4

MRID Citation:	MRID 47248505

	Combined Residues of Chlorothalonil and SDS-3701(ppm)

	<1.02

	<0.11

	<1.62

	<3.92

	<0.19

	<0.60

	<0.35

	<0.47



Figure I-5.  Lognormal probability plot of chlorothalonil field trial
data for rhubarb.

Figure I-6.  Tolerance spreadsheet summary of chlorothalonil field trial
data for rhubarb.

Vegetable, Fruiting (Crop Group 8)

The representative commodities of fruiting vegetables are tomato and
pepper (bell and non-bell).  According to the Residue Chemistry RED
Chapter of Chlorothalonil  SEQ CHAPTER \h \r 1   SEQ CHAPTER \h \r 1  
SEQ CHAPTER \h \r 1  (DP# 201522, 6/7/95, W. Smith), adequate field
trial data are available to support the use of chlorothalonil on tomato,
provided the registrant amends all pertinent product labels as intended
to specify a maximum number of applications or a maximum seasonal rate. 
The available data would support a maximum of 11 applications per season
at 2.3 lb ai/A/application (total rate of 25.3 lb ai/A) for tomato. 
Based on these data, the Agency established a 5.0-ppm tolerance for the
combined residues of chlorothalonil and its 4-hydroxy metabolite on
tomato.  The available crop field trial data for tomato were not used
for tolerance calculations below. 

Pepper (Bell and Non-bell)

The dataset used to establish a tolerance for residues of chlorothalonil
in/on fruiting vegetables consisted of field trial data for pepper (bell
and non-bell) representing application rates of 8.1-9.2 lb ai/A (7-8
applications at 1.07-1.17 lb ai/A/application) with a 2- to 3-day PHI. 
As specified by the SOP, the field trial application rates and PHIs are
within 25% of the maximum label application rate and minimum label PHI,
respectively.  HED notes that one non-bell pepper field trial received
only 6 applications at 1.12-3.36 lb ai/A/application.  Since the total
rate (9.0 lb ai/A) and PHI (2 days) for this trial were within 25%,
these data were included in the dataset.  The residue values that were
entered into the tolerance spreadsheet are provided in Table I-4.

All field trial sample results for chlorothalonil in/on pepper were
above the LOQ while residues of SDS-3701 were below the LOQ in/on all
samples (validated LOQ = 0.03 ppm for chlorothalonil and SDS-3701).  The
bell pepper dataset was large (18 samples) and the non-bell pepper
dataset was small (12 samples).  Visual inspection of the lognormal
probability plots (Figures I-7 and I-9) and the results from the
approximate Shapiro-Francia test statistic (Figures I-8 and I-10)
indicated that the pepper datasets were reasonably lognormal.  

Using the tolerance spreadsheet, the recommended tolerances are 6.0 ppm
for bell pepper and 3.0 ppm for non-bell pepper.  As the use directions
for tomatoes and the other fruiting vegetables differ significantly,
separate tolerances should be established for “tomato” and
“vegetable, fruiting, group 8, except tomato.”  The recommended
tolerance for vegetable, fruiting, group 8, except tomato is 6.0 ppm,
based on residue data from bell pepper.  

Table I-4.	Residue data used to calculate tolerance for combined
residues of chlorothalonil and SDS-3701 on pepper (bell and non-bell).

Regulator:	EPA	EPA

Chemical:	Chlorothalonil	Chlorothalonil

Crop:	Pepper, Bell	Pepper, Non-bell

PHI:	2-3 days	2-3 days

Total App. Rate:	8.05-9.17 lb ai/A (FlC formulation)	8.95-9.16 lb ai/A
(WG formulation)

Submitter:	IR-4	IR-4

MRID Citation:	MRID 47248501	MRID 47248502

	Combined Residues of Chlorothalonil and SDS-3701(ppm)

	<3.13	<1.43

	<2.63	<1.83

	<1.73	<0.46

	<1.73	<0.81

	<3.53	<1.53

	<2.33	<1.73

	<1.33	<0.81

	<1.63	<0.65

	<0.85	<1.13

	<0.72	<0.67

	<0.69	<0.63

	<0.36	<0.67

	<0.56



<0.48



<1.63



<1.63



<0.97



<0.65

	

Figure I-7.  Lognormal probability plot of chlorothalonil field trial
data for bell pepper.

Figure I-8.  Tolerance spreadsheet summary of chlorothalonil field trial
data for bell pepper.

Figure I-9.  Lognormal probability plot of chlorothalonil field trial
data for non-bell pepper.

Figure I-10.  Tolerance spreadsheet summary of chlorothalonil field
trial data for non-bell pepper.

 

Chlorothalonil	Summary of Analytical Chemistry and Residue Data	DP#: 
346319

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