Document ID: EPA-HQ-OPP-2009-0262-0002
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2009-05-06T04:00Z

FILE NAME:  Valent.doc (Feb 4, 2009)

EPA Registration Division contact: Kable (Bo) Davis (703-306-0415)

[9F7530]

Summary of Petition

EPA has received a pesticide petition (9F7530) from   SEQ CHAPTER \h \r
1 Valent U.S.A. Corporation, P.O. Box 8025 Walnut Creek, CA 94596 (as
Agent for Sumitomo Chemical Co., Ltd), 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, by establishing a tolerance for
residues of the insecticide chemical clothianidin,
(E)-1-(2-chloro-1,3-thiazol-5-ylmethyl)-3-methyl-2-nitroguanidine, in or
on the following agricultural commodities:

Commodity	Proposed Tolerance

Parts per million

(For parent only unless indicated otherwise)

Fig	0.05

Pomegranate 	0.2

	

EPA has determined that the petition contains data or information
regarding the elements set forth in section 408(d)(2) of the FFDCA;
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 clothianidin is adequately
understood for the purpose of granting the proposed tolerances.

2.  Analytical method.  Adequate enforcement methodology (liquid
chromatography/mass spectroscopy/mass spectroscopy, LC/MS/MS analysis)
is available to enforce the tolerance expression.  

3. Magnitude of residues.  Residue data has been submitted which
adequately support the requested tolerances. 

B. Toxicological Profile

A complete, valid and reliable database of mammalian and genetic
toxicology studies has been submitted to EPA that supports the proposed
tolerances for clothianidin. The nature of the toxic effects caused by
clothianidin, as well as the no observed adverse effect level (NOAEL)
and the lowest observed adverse effect level (LOAEL) from the toxicity
studies reviewed, are discussed in the Federal Register of May 30, 2003
(68 FR 32390) (FRL-7306-8). 
[http://www.epa.gov/EPA-PEST/2003/May/Day-30/p13564.htm

C. Aggregate Exposure and Risk Assessment

 i. Dietary Exposure – food.  Dietary exposure (food) assessments were
conducted to evaluate the potential risk due to acute and chronic
dietary exposure of the U.S. population and various subgroups to
combined residues of clothianidin and its metabolite TMG. . Residues
from use of clothianidin on fig and pomegranate were not included in the
current assessment because the contribution to the overall aggregate
exposure is considered negligible.  These minor crop residues will be
included in the aggregate exposure assessment at a later date.

The Cumulative and Aggregate Risk Evaluation System (CARES) Version 3.0b
was used to conduct these assessments using a combination (when
available) of actual or generated residue data, experimentally obtained
processing factors, and an estimation of percent crop treated.  Default
factors or tolerance level residues were used when experimentally
determined data were not available 

ii. Dietary Exposure – water. Dietary exposure from drinking water was
estimated using a Tier II PRZM/EXAMS assessment to determine the EDWCs
in the Standard Index Reservoir associated with clothianidin uses.  A
30-year daily concentration time series data set generated from the
scenario with the maximum (worst case) EDWS estimates was then imported
into CARES Water module in order to calculate acute and chronic drinking
water and aggregate risks. 

iii. Non-Dietary Exposure – residential/recreational turf. 
Non-dietary exposure to clothianidin from residential or recreational
(turf grass) application scenarios was assessed using the CARES
Residential module.  The risk assessment was conducted using residential
adult applicator and post-application assumptions.  

iv.  Aggregate Assessment of Risks.  The aggregate acute risk assessment
includes food, water and residential exposures.  Because chronic
exposure scenarios are not expected from residential uses of
clothianidin, the chronic exposure risk assessment only includes food
and water exposures.  

For acute risk assessment scenarios, the acute population adjusted dose
(aPAD) of 0.025 mg/kg was used to assess risks from acute dietary
exposure to the general population and to various sub-populations.  The
aPAD is based on the NOAEL of 25 mg/kg/day from an acute neurotoxicity
study (general population) or a developmental toxicity study (females
13-49 years of age) with an FQPA safety factor of 10.   

For chronic risk assessment scenarios, the chronic population adjusted
dose (cPAD) used for the U.S. population and all subpopulations is
0.0098 mg/kg/day based on a 2-generation reproduction study NOAEL of 9.8
mg/kg/day and an FQPA safety factor of 10.

Based on these risk assessments, the margins of exposure (MOE) for all
routes of exposure and all population subgroups exceed 1000 and
therefore do not exceed EPA’s level of concern.  

D44. Cumulative Effects.  Section 408(b)(2)(D)(v) requires that the
Agency must consider available information concerning the cumulative
effects of a particular pesticide's residues and other substances that
have a common mechanism of toxicity. Clothianidin is a member of the
neonicotinoid class of pesticides and is a metabolite of thiamethoxam.
Structural similarities or common effects do not constitute a common
mechanism of toxicity and there is currently no evidence that
neonicotinoids share a common mechanism of toxicity.  For purposes of
this petition, clothianidin residues from use of clothianidin and
thiamethoxam have been considered.  

E. Safety Determination.  The toxicological database for clothianidin is
complete, with the exception of a developmental immunotoxicity study
that has recently been submitted to the Agency for review.  Until this
study is reviewed and accepted,.  EPA has determined there is
insufficient data to justify the selection of an additional safety
factor for the protection of infants and children lower than the default
value of 10X for both single and repeated doses.  Therefore, a data base
uncertainty factor (UFDB), has been applied to both single and repeated
dose exposure scenarios (i.e., acute and chronic RfDs, short- and
intermediate-term incidental oral exposures, resulting from residential
uses of clothiandin) to account for the lack of the developmental
immunotoxicity study with clothianidin.  

The results of the aggregate exposure risk assessment (taking into
account the full 1000X margin of safety) indicate the MOE’s do not
exceed EPA’s level of concern.  There is therefore a reasonable
certainty that no harm will result to the general population or to any
population subgroup resulting from aggregate exposure to residues of
clothianidin.  

F. International Tolerances   Canadian maximum residue limits (MRL)
have been established for residues of clothianidin at 0.01
milligram/kilogram (mg/kg) in milk, corn and canola. Clothianidin has
not been evaluated by the JMPR and there are no Codex Maximum Residue
Limits (MRL) established.