
[Federal Register: May 7, 2008 (Volume 73, Number 89)]
[Rules and Regulations]               
[Page 25533-25539]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr07my08-14]                         

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[EPA-HQ-OPP-2007-0398; FRL-8362-2]

 
Spirodiclofen; Pesticide Tolerances

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes a tolerance for residues of 
spirodiclofen in or on hop, dried cones. Interregional Research Project 
Number 4 (IR-4) requested this tolerance under the Federal Food, Drug, 
and Cosmetic Act (FFDCA).

DATES: This regulation is effective May 7, 2008. Objections and 
requests for hearings must be received on or before July 7, 2008, and 
must be filed in accordance with the instructions provided in 40 CFR 
part 178 (see also

[[Page 25534]]

Unit I.C. of the SUPPLEMENTARY INFORMATION).

ADDRESSES: EPA has established a docket for this action under docket 
identification (ID) number EPA-HQ-OPP-2007-0398. To access the 
electronic docket, go to http://www.regulations.gov, select ``Advanced 
Search,'' then ``Docket Search.'' Insert the docket ID number where 
indicated and select the ``Submit'' button. Follow the instructions on 
the regulations.gov website to view the docket index or access 
available documents. All documents in the docket are listed in the 
docket index available in regulations.gov. Although listed in the 
index, some information is not publicly available, e.g., Confidential 
Business Information (CBI) or other information whose disclosure is 
restricted by statute. Certain other material, such as copyrighted 
material, is not placed on the Internet and will be publicly available 
only in hard copy form. Publicly available docket materials are 
available in the electronic docket at http://www.regulations.gov, or, 
if only available in hard copy, at the OPP Regulatory Public Docket in 
Rm. S-4400, One Potomac Yard (South Bldg.), 2777 S. Crystal Dr., 
Arlington, VA. The Docket Facility is open from 8:30 a.m. to 4 p.m., 
Monday through Friday, excluding legal holidays. The Docket Facility 
telephone number is (703) 305-5805.

FOR FURTHER INFORMATION CONTACT: Susan Stanton, Registration Division 
(7505P), Office of Pesticide Programs, Environmental Protection Agency, 
1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone 
number: (703) 305-5218; e-mail address: stanton.susan@epa.gov.

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me?

    You may be potentially affected by this action if you are an 
agricultural producer, food manufacturer, or pesticide manufacturer. 
Potentially affected entities may include, but are not limited to those 
engaged in the following activities:
     Crop production (NAICS code 111).
     Animal production (NAICS code 112).
     Food manufacturing (NAICS code 311).
     Pesticide manufacturing (NAICS code 32532).
    This listing is not intended to be exhaustive, but rather to 
provide a guide for readers regarding entities likely to be affected by 
this action. Other types of entities not listed in this unit could also 
be affected. The North American Industrial Classification System 
(NAICS) codes have been provided to assist you and others in 
determining whether this action might apply to certain entities. If you 
have any questions regarding the applicability of this action to a 
particular entity, consult the person listed under FOR FURTHER 
INFORMATION CONTACT.

B. How Can I Access Electronic Copies of this Document?

    In addition to accessing an electronic copy of this Federal 
Register document through the electronic docket at http://
www.regulations.gov, you may access this Federal Register document 
electronically through the EPA Internet under the ``Federal Register'' 
listings at http://www.epa.gov/fedrgstr. You may also access a 
frequently updated electronic version of EPA's tolerance regulations at 
40 CFR part 180 through the Government Printing Office's pilot e-CFR 
site at http://www.gpoaccess.gov/ecfr.

C. Can I File an Objection or Hearing Request?

    Under section 408(g) of FFDCA, any person may file an objection to 
any aspect of this regulation and may also request a hearing on those 
objections. You must file your objection or request a hearing on this 
regulation in accordance with the instructions provided in 40 CFR part 
178. To ensure proper receipt by EPA, you must identify docket ID 
number EPA-HQ-OPP-2007-0398 in the subject line on the first page of 
your submission. All requests must be in writing, and must be mailed or 
delivered to the Hearing Clerk as required by 40 CFR part 178 on or 
before July 7, 2008.
    In addition to filing an objection or hearing request with the 
Hearing Clerk as described in 40 CFR part 178, please submit a copy of 
the filing that does not contain any CBI for inclusion in the public 
docket that is described in ADDRESSES. Information not marked 
confidential pursuant to 40 CFR part 2 may be disclosed publicly by EPA 
without prior notice. Submit this copy, identified by docket ID number 
EPA-HQ-OPP-2007-0398, by one of the following methods:
     Federal eRulemaking Portal: http://www.regulations.gov. 
Follow the on-line instructions for submitting comments.
     Mail: Office of Pesticide Programs (OPP) Regulatory Public 
Docket (7502P), Environmental Protection Agency, 1200 Pennsylvania 
Ave., NW., Washington, DC 20460-0001.
     Delivery: OPP Regulatory Public Docket (7502P), 
Environmental Protection Agency, Rm. S-4400, One Potomac Yard (South 
Bldg.), 2777 S. Crystal Dr., Arlington, VA. Deliveries are only 
accepted during the Docket's normal hours of operation (8:30 a.m. to 4 
p.m., Monday through Friday, excluding legal holidays). Special 
arrangements should be made for deliveries of boxed information. The 
Docket Facility telephone number is (703) 305-5805.

II. Petition for Tolerance

    In the Federal Register of June 27, 2007 (72 FR 35237) (FRL-8134-
9), EPA issued a notice pursuant to section 408(d)(3) of FFDCA, 21 
U.S.C. 346a(d)(3), announcing the filing of a pesticide petition (PP 
7E7204) by Interregional Research Project Number 4 (IR-4), 500 College 
Road East, Suite 201W, Princeton, NJ 08540. The petition requested that 
40 CFR 180.608 be amended by establishing tolerances for residues of 
the insecticide/miticide spirodiclofen, 3-(2,4-dichlorophenyl)-2-oxo-1-
oxaspiro[4,5]dec-3-en-4-yl 2,2-dimethylbutanoate, in or on hop, dried 
cones at 30 parts per million (ppm). That notice referenced a summary 
of the petition prepared by Bayer CropScience, the registrant, which is 
available to the public in the docket, http://www.regulations.gov. 
There were no comments received in response to the notice of filing.

III. Aggregate Risk Assessment and Determination of Safety

    Section 408(b)(2)(A)(i) of FFDCA allows EPA to establish a 
tolerance (the legal limit for a pesticide chemical residue in or on a 
food) only if EPA determines that the tolerance is ``safe.'' Section 
408(b)(2)(A)(ii) of FFDCA defines ``safe'' to mean that ``there is a 
reasonable certainty that no harm will result from aggregate exposure 
to the pesticide chemical residue, including all anticipated dietary 
exposures and all other exposures for which there is reliable 
information.'' This includes exposure through drinking water and in 
residential settings, but does not include occupational exposure. 
Section 408(b)(2)(C) of FFDCA requires EPA to give special 
consideration to exposure of infants and children to the pesticide 
chemical residue in establishing a tolerance and to ``ensure that there 
is a reasonable certainty that no harm will result to infants and 
children from aggregate exposure to the pesticide chemical 
residue....''
    Consistent with section 408(b)(2)(D) of FFDCA, and the factors 
specified in section 408(b)(2)(D) of FFDCA, EPA has

[[Page 25535]]

reviewed the available scientific data and other relevant information 
in support of this action. EPA has sufficient data to assess the 
hazards of and to make a determination on aggregate exposure for the 
petitioned-for tolerances for residues of spirodiclofen on hop, dried 
cones at 30 ppm. EPA's assessment of exposures and risks associated 
with establishing tolerances follows.

A. Toxicological Profile

    EPA has evaluated the available toxicity data and considered its 
validity, completeness, and reliability as well as the relationship of 
the results of the studies to human risk. EPA has also considered 
available information concerning the variability of the sensitivities 
of major identifiable subgroups of consumers, including infants and 
children.
    Spirodiclofen has a low acute toxicity via oral, dermal or 
inhalation routes. It is not an eye or dermal irritant; however, it is 
a potential skin sensitizer. Following oral administration, 
spirodiclofen is rapidly absorbed, metabolized and excreted via urine 
and feces. The most sensitive target organ of spirodiclofen is the 
adrenal gland. Adrenal effects (e.g., increased adrenal weights, 
increased incidence and severity of small cytoplasmic vacuolation in 
the cortex of adrenal glands) were observed in rats, dogs and mice with 
the dog being the most sensitive species.
    There was no evidence of neurotoxicity in the acute neurotoxicity 
study in rats. In the subchronic neurotoxicity study in rats, 
functional-observational-battery (FOB) effects and decreased motor and 
locomotor activities were observed in females at the high dose only. 
The effects were considered to be due to the large decrease in body 
weight in these animals. In one of two developmental neurotoxicity 
(DNT) studies in rats, a decrease in retention (memory) was observed in 
the postnatal day (PND) 60 females only. These effects were not seen in 
a repeated DNT study conducted using the same doses and experimental 
conditions.
    There was no evidence (qualitative or quantitative) of increased 
susceptibility in the rabbit developmental toxicity study or the rat 
reproduction toxicity study following in utero or postnatal exposure to 
spirodiclofen. However, evidence of quantitative susceptibility was 
observed in a rat developmental toxicity study where an increased 
incidence of slight dilatation of the renal pelvis was observed at a 
dose (1,000 milligrams/kilogram/day (mg/kg/day)) which did not cause 
any maternal toxicity. The results of the two DNT studies for 
spirodiclofen also suggest increased susceptibility. In the first 
study, memory and brain morphometric differences were observed at doses 
that did not result in maternal toxicity. While these effects were not 
seen in the second DNT study, body weight changes were seen at non-
maternally toxic doses.
    EPA has classified spirodiclofen as ``likely to be carcinogenic to 
humans'' by the oral route of exposure, based on evidence of testes 
Leydig cell adenomas in male rats, uterine adenomas and/or 
adenocarcinoma in female rats, and liver tumors in mice. EPA has 
determined that quantification of human cancer risk using a linear low-
dose extrapolation approach is appropriate.
    Specific information on the studies received and the nature of the 
adverse effects caused by spirodiclofen as well as the no-observed-
adverse-effect-level (NOAEL) and the lowest-observed-adverse-effect-
level (LOAEL) from the toxicity studies can be found at http://
www.regulations.gov in the document Spirodiclofen. Petition No. 7E7204. 
Human Health Risk Assessment for Use on Hops at pages 45-48 in docket 
ID number EPA-HQ-OPP-2007-0398.

B. Toxicological Endpoints

    For hazards that have a threshold below which there is no 
appreciable risk, a toxicological point of departure (POD) is 
identified as the basis for derivation of reference values for risk 
assessment. The POD may be defined as the highest dose at which no 
adverse effects are observed (the NOAEL) in the toxicology study 
identified as appropriate for use in risk assessment. However, if a 
NOAEL cannot be determined, the lowest dose at which adverse effects of 
concern are identified (the LOAEL) or a Benchmark Dose (BMD) approach 
is sometimes used for risk assessment. Uncertainty/safety factors (UFs) 
are used in conjunction with the POD to take into account uncertainties 
inherent in the extrapolation from laboratory animal data to humans and 
in the variations in sensitivity among members of the human population 
as well as other unknowns. Safety is assessed for acute and chronic 
dietary risks by comparing aggregate food and water exposure to the 
pesticide to the acute population adjusted dose (aPAD) and chronic 
population adjusted dose (cPAD). The aPAD and cPAD are calculated by 
dividing the POD by all applicable UFs. Aggregate short-term, 
intermediate-term, and chronic-term risks are evaluated by comparing 
food, water, and residential exposure to the POD to ensure that the 
margin of exposure (MOE) called for by the product of all applicable 
UFs is not exceeded. This latter value is referred to as the Level of 
Concern (LOC).
    For non-threshold risks, the Agency assumes that any amount of 
exposure will lead to some degree of risk. Thus, the Agency estimates 
risk in terms of the probability of an occurrence of the adverse effect 
greater than that expected in a lifetime. For more information on the 
general principles EPA uses in risk characterization and a complete 
description of the risk assessment process, see http://www.epa.gov/
pesticides/factsheets/riskassess.htm.
    A summary of the toxicological endpoints for spirodiclofen used for 
human risk assessment can be found at http://www.regulations.gov in the 
document Spirodiclofen. Petition No. 7E7204. Human Health Risk 
Assessment for Use on Hops at page 34 in docket ID number EPA-HQ-OPP-
2007-0398.

C. Exposure Assessment

    1. Dietary exposure from food and feed uses. In evaluating dietary 
exposure to spirodiclofen, EPA considered exposure under the 
petitioned-for tolerances as well as all existing spirodiclofen 
tolerances in 40 CFR 180.608. EPA assessed dietary exposures from 
spirodiclofen in food as follows:
    i. Acute exposure. Quantitative acute dietary exposure and risk 
assessments are performed for a food-use pesticide, if a toxicological 
study has indicated the possibility of an effect of concern occurring 
as a result of a 1-day or single exposure. No such effects were 
identified in the toxicological studies for spirodiclofen; therefore, a 
quantitative acute dietary exposure assessment is unnecessary.
    ii. Chronic exposure. In conducting the chronic dietary exposure 
assessment EPA used the food consumption data from the USDA 1994-1996 
and 1998 CSFII. As to residue levels in food, EPA assumed that all food 
commodities contain residues at the average field trial level. EPA also 
assumed average field trial residues for feed commodities in 
calculating anticipated livestock dietary burdens and anticipated 
residues in meat and milk. Residue estimates were further refined using 
available experimentally-derived processing factors as well as 
projected percent crop treated (PPCT) information for several crops.
    iii. Cancer. EPA has classified spirodiclofen as ``likely to be 
carcinogenic to humans'' by the oral route of exposure and determined 
that quantification of human cancer risk

[[Page 25536]]

using a linear low-dose extrapolation approach is appropriate. Cancer 
risk was assessed using the same exposure assumptions as discussed in 
Unit III.C.1.ii. above.
    iv. Anticipated residue and percent crop treated (PCT) information. 
Section 408(b)(2)(E) of FFDCA authorizes EPA to use available data and 
information on the anticipated residue levels of pesticide residues in 
food and the actual levels of pesticide residues that have been 
measured in food. If EPA relies on such information, EPA must require 
pursuant to FFDCA section 408(f)(1) that data be provided 5 years after 
the tolerance is established, modified, or left in effect, 
demonstrating that the levels in food are not above the levels 
anticipated. For the present action, EPA will issue such data call-ins 
as are required by FFDCA section 408(b)(2)(E) and authorized under 
FFDCA section 408(f)(1). Data will be required to be submitted no later 
than 5 years from the date of issuance of these tolerances.
    Section 408(b)(2)(F) of FFDCA states that the Agency may use data 
on the actual percent of food treated for assessing chronic dietary 
risk only if:
     Condition a: The data used are reliable and provide a 
valid basis to show what percentage of the food derived from such crop 
is likely to contain the pesticide residue.
     Condition b: The exposure estimate does not underestimate 
exposure for any significant subpopulation group.
     Condition c: Data are available on pesticide use and food 
consumption in a particular area, the exposure estimate does not 
understate exposure for the population in such area.
    In addition, the Agency must provide for periodic evaluation of any 
estimates used. To provide for the periodic evaluation of the estimate 
of PCT as required by FFDCA section 408(b)(2)(F), EPA may require 
registrants to submit data on PCT.
    The Agency used projected percent crop treated (PPCT) information 
for the new crop (hops) as well as several currently registered crops 
(apples, grapes, oranges and peaches). Since spirodiclofen has only 
been registered on these crops since 2005, PCT estimates based on 
actual usage data were not deemed sufficient indicators of potential 
usage on currently registered crops. The Agency used PPCT information 
as follows: Hops 92%; apples 15%; grapes 7%; oranges (except temple) 
14%; peaches 10%.
    EPA estimates PPCT for spirodiclofen use by assuming that the PCT 
during the pesticide's initial 5 years of use on a specific use site 
will not exceed the average PCT of the dominant or market leader 
pesticide (i.e. the one with the greatest PCT) on that site over the 
three most recent surveys. Comparisons are only made among pesticides 
of the same pesticide types (i.e., the dominant insecticide on the use 
site is selected for comparison with the new insecticide/miticide). 
Since spirodiclofen is a miticide, EPA identified miticides that are 
the market leaders to project PCT. Petroleum distillate and petroleum 
oil were excluded as market leaders and the next miticide market leader 
was chosen. The PCTs included in the average may be for the same 
pesticide or for different pesticides, since the same or different 
pesticides may dominate for each year selected. Typically, EPA uses 
U.S. Department of Agriculture/National Agricultural Statistics Service 
(USDA/NASS) as the source for raw PCT data, because it is publicly 
available and does not have to be calculated from available data 
sources. When a specific use site is not surveyed by USDA/NASS, EPA 
uses proprietary data and calculates the estimated PCT.
    These estimated PPCTs, based on the average PCT of the market 
leaders, are appropriate for use in chronic dietary risk assessment. 
This method of estimating PPCT for a new use of a registered pesticide 
or a new pesticide produces a high-end estimate that is unlikely, in 
most cases, to be exceeded during the initial five years of actual use. 
The predominant factors that bear on whether the PPCT could be exceeded 
are whether the new pesticide use or new pesticide is more efficacious 
or controls a broader spectrum of pests than the dominant pesticide(s). 
All relevant information currently available regarding the predominant 
factors has been considered for the use of spirodiclofen on hops; 
oranges, except temple; grapes, all; peaches; and apples; and it is 
unlikely that these spirodiclofen uses will exceed the estimated PPCTs 
during the next 5 years, because the target pest range of the market 
leaders is generally broader than spirodiclofen's, often including both 
insect and mite pests. Furthermore, the Agency has received no Section 
18 emergency exemption requests for spirodiclofen and there are no 
readily discernible resistance issues with target pest mites, which 
might indicate an increased need for spirodiclofen on these crops.
    The Agency believes that the three conditions discussed in Unit 
III.C.1.iv. have been met. With respect to Condition a, PCT estimates 
are derived from Federal and private market survey data, which are 
reliable and have a valid basis. The Agency is reasonably certain that 
the percentage of the food treated is not likely to be an 
underestimation. As to Conditions b and c, regional consumption 
information and consumption information for significant subpopulations 
is taken into account through EPA's computer-based model for evaluating 
the exposure of significant subpopulations including several regional 
groups. Use of this consumption information in EPA's risk assessment 
process ensures that EPA's exposure estimate does not understate 
exposure for any significant subpopulation group and allows the Agency 
to be reasonably certain that no regional population is exposed to 
residue levels higher than those estimated by the Agency. Other than 
the data available through national food consumption surveys, EPA does 
not have available reliable information on the regional consumption of 
food to which spirodiclofen may be applied in a particular area.
    2. Dietary exposure from drinking water. The Agency used screening 
level water exposure models in the dietary exposure analysis and risk 
assessment for spirodiclofen in drinking water. These simulation models 
take into account data on the physical, chemical, and fate/transport 
characteristics of spirodiclofen. Further information regarding EPA 
drinking water models used in pesticide exposure assessment can be 
found at http://www.epa.gov/oppefed1/models/water/index.htm.
    Based on the Pesticide Root Zone Model/Exposure Analysis Modeling 
System (PRZM/EXAMS) and Screening Concentration in Ground Water (SCI-
GROW) models, the estimated drinking water concentrations (EDWCs) of 
spirodiclofen for chronic exposures for non-cancer assessments are 
estimated to be 4.99 parts per billion (ppb) for surface water and 0.44 
ppb for ground water; the EDWCs of spirodiclofen for chronic exposures 
for cancer assessments are estimated to be 1.67 ppb for surface water 
and 0.44 ppb for ground water.
    Modeled estimates of drinking water concentrations were directly 
entered into the dietary exposure model. For chronic dietary risk 
assessment, the water concentration of value 4.99 ppb was used to 
assess the contribution to drinking water. For cancer dietary risk 
assessment, the water concentration of value 1.67 ppb was used to 
assess the contribution to drinking water.
    3. From non-dietary exposure. The term ``residential exposure'' is 
used in this document to refer to non-occupational, non-dietary 
exposure (e.g., for lawn and garden pest control, indoor pest control, 
termiticides, and flea and tick control on pets).

[[Page 25537]]

Spirodiclofen is not registered for any specific use patterns that 
would result in residential exposure.
    4. Cumulative effects from substances with a common mechanism of 
toxicity. Section 408(b)(2)(D)(v) of FFDCA requires that, when 
considering whether to establish, modify, or revoke a tolerance, the 
Agency consider ``available information'' concerning the cumulative 
effects of a particular pesticide's residues and ``other substances 
that have a common mechanism of toxicity.''
    EPA has not found spirodiclofen to share a common mechanism of 
toxicity with any other substances, and spirodiclofen does not appear 
to produce a toxic metabolite produced by other substances. For the 
purposes of this tolerance action, therefore, EPA has assumed that 
spirodiclofen does not have a common mechanism of toxicity with other 
substances. For information regarding EPA's efforts to determine which 
chemicals have a common mechanism of toxicity and to evaluate the 
cumulative effects of such chemicals, see EPA's website at http://
www.epa.gov/pesticides/cumulative.

D. Safety Factor for Infants and Children

    1. In general. Section 408(b)(2)(c) of FFDCA provides that EPA 
shall apply an additional tenfold (10X) margin of safety for infants 
and children in the case of threshold effects to account for prenatal 
and postnatal toxicity and the completeness of the database on toxicity 
and exposure unless EPA determines based on reliable data that a 
different margin of safety will be safe for infants and children. This 
additional margin of safety is commonly referred to as the FQPA safety 
factor (SF). In applying this provision, EPA either retains the default 
value of 10X, or uses a different additional safety factor when 
reliable data available to EPA support the choice of a different 
factor.
    2. Prenatal and postnatal sensitivity. The prenatal and postnatal 
toxicity database for spirodiclofen includes prenatal developmental 
toxicity studies in rats and rabbits, a 2-generation reproduction 
toxicity study in rats and two developmental neurotoxicity (DNT) 
studies in rats. There was no evidence (qualitative or quantitative) of 
increased susceptibility in the rabbit developmental toxicity study or 
the rat reproduction toxicity study following in utero or postnatal 
exposure to spirodiclofen. However, evidence of quantitative 
susceptibility was observed in the rat developmental toxicity study 
where an increased incidence of slight dilatation of the renal pelvis 
was observed at a dose (1,000 mg/kg/day) which did not cause any 
maternal toxicity. The results of the two available DNT studies for 
spirodiclofen also suggest increased susceptibility. In the first 
study, memory and brain morphometric differences were observed at doses 
that did not result in maternal toxicity. While these effects were not 
seen in the second DNT study, body weight changes were seen at non-
maternally toxic doses.
    The degree of concern is low for the quantitative susceptibility 
seen in the prenatal developmental and DNT studies in the rat for the 
following reasons:
    The renal pelvic dilation seen in the rat developmental toxicity 
study was slight and observed only at the limit dose without 
statistical significance or dose response. Renal pelvic dilation was 
considered to be a developmental delay and not a severe developmental 
effect. The low background incidence of renal pelvic dilations seen in 
this study may be idiosyncratic to this strain (Wistar) of rats, since 
they are commonly seen at higher incidences in other strains (Sprague-
Dawley or Fisher). In addition, doses selected for risk assessment of 
spirodiclofen are much lower than the dose that caused these 
developmental delays.
    The degree of concern for the increased susceptibility seen in the 
second DNT study is also low, because there is a well established 
NOAEL, the toxicity is marginal (slight changes in body weights) and 
all developmental/functional parameters were comparable to controls. In 
addition, doses selected for risk assessment of spirodiclofen are much 
lower than the dose that caused these marginal changes in the body 
weights of offspring in the second DNT study.
    In the first DNT study, no significant differences were noted 
between treated and control groups in reproductive parameters (litter 
size, sex ratio, number of deaths, live birth, viability and 
lactation), and no treatment-related clinical signs were observed at 
any dose in either sex. No treatment-related differences in functional 
observational battery (FOB), motor activity or locomotor activity were 
observed during the pre-weaning and post-weaning periods; and no 
treatment-related differences in the passive avoidance tests were 
observed at any dose. The trials to criterion for the memory phase of 
the water maze test showed a treatment-related effect at all doses for 
postnatal day (PND) 60 females. The memory effects occurred only in 
adults and were not seen in younger animals; therefore, these effects 
do not raise a concern for susceptibility.
    On postmortem examination, differences in certain morphometric 
measurements (caudate putamen, parietal cortex, hippocampal gyrus and 
dentate gyrus) were observed at the high dose, the only dose for which 
morphometric measurements were made. The magnitude of these effects was 
minute but statistically significant. The lack of measurements at the 
mid- and low doses precluded establishment of a clear NOAEL or a 
determination as to the toxicological significance of these minor 
changes at the high dose. Therefore, EPA requested similar morphometric 
analyses at the mid- and low doses in both sexes. Since inappropriate 
preservation of brain tissues from the first study precluded additional 
morphometric analyses, the registrant elected to conduct a second DNT 
study using the same doses and experimental conditions. The 
morphometric differences observed in the first DNT study were not seen 
in the second study. EPA has no concern for the increased 
susceptibility seen in the first DNT study because:
     The magnitude of the morphometric changes was minor.
     They occurred at the high dose; the doses selected for 
risk assessment are significantly lower than the dose at which these 
effects were seen.
     No other neurotoxic effects were observed in young pups in 
the first DNT study.
     The results were not reproduced in the second study 
conducted using identical doses and experimental conditions. The 
results of the second study suggest that the findings in the first 
study are spurious and not toxicologically significant.
    3. Conclusion. EPA has determined that reliable data show the 
safety of infants and children would be adequately protected if the 
FQPA SF were reduced to 1X for chronic dietary exposures, the only 
exposures considered in this risk assessment, since an acute dietary 
endpoint has not been identified for spirodiclofen and there are no 
residential uses that would result in short-term or intermediate-term 
non-dietary exposures. The decision to reduce the FQPA SF to 1X for 
chronic dietary exposures is based on the following findings:
    i. The toxicity database for spirodiclofen is complete.
    ii. Based on the results of acute, subchronic and developmental 
neurotoxicity studies in rats (see units III.A. and III.D.2.), EPA has 
concluded that spirodiclofen is unlikely to be a neurotoxic or 
developmentally

[[Page 25538]]

neurotoxic compound and there is no need for a developmental 
neurotoxicity study or additional UFs to account for neurotoxicity.
    iii. There was no evidence (qualitative or quantitative) of 
increased susceptibility in the rabbit developmental toxicity study or 
the rat reproduction toxicity study following in utero or postnatal 
exposure to spirodiclofen. The degree of concern is low for the 
quantitative susceptibility seen in the prenatal developmental and DNT 
studies in the rat, and the Agency did not identify any residual 
uncertainties after establishing toxicity endpoints and traditional 
uncertainty factors to be used in the risk assessment of spirodiclofen.
    iv. There are no residual uncertainties identified in the exposure 
databases. The dietary food exposure assessments were refined using 
reliable PPCT information and anticipated residue values calculated 
from residue field trial results. EPA made conservative (protective) 
assumptions in the ground and surface water modeling used to assess 
exposure to spirodiclofen in drinking water. Residential exposures are 
not expected. These assessments will not underestimate the exposure and 
risks posed by spirodiclofen.

E. Aggregate Risks and Determination of Safety

    EPA determines whether acute and chronic pesticide exposures are 
safe by comparing aggregate exposure estimates to the aPAD and cPAD. 
The aPAD and cPAD represent the highest safe exposures, taking into 
account all appropriate SFs. EPA calculates the aPAD and cPAD by 
dividing the POD by all applicable UFs. For linear cancer risks, EPA 
calculates the probability of additional cancer cases given the 
estimated aggregate exposure. Short-term, intermediate-term, and 
chronic-term risks are evaluated by comparing the estimated aggregate 
food, water, and residential exposure to the POD to ensure that the MOE 
called for by the product of all applicable UFs is not exceeded.
    1. Acute risk. An acute aggregate risk assessment takes into 
account exposure estimates from acute dietary consumption of food and 
drinking water. No adverse effect resulting from a single-oral exposure 
was identified and no acute dietary endpoint was selected. Therefore, 
spirodiclofen is not expected to pose an acute risk.
    2. Chronic risk. Using the exposure assumptions described in this 
unit for chronic exposure, EPA has concluded that chronic exposure to 
spirodiclofen from food and water will utilize 3.2% of the cPAD for 
infants less than 1 year old, the population group receiving the 
greatest exposure. There are no residential uses for spirodiclofen.
    3. Short-term and intermediate-term risk. Short-term and 
intermediate-term aggregate exposures take into account short-term and 
intermediate-term residential exposures plus chronic exposure to food 
and water (considered to be a background exposure level). Spirodiclofen 
is not registered for any use patterns that would result in residential 
exposure. Therefore, the short-term/intermediate-term aggregate risk is 
the sum of the risk from exposure to spirodiclofen through food and 
water and will not be greater than the chronic aggregate risk.
    4. Aggregate cancer risk for U.S. population. Using the exposure 
assumptions described in Unit III.C.1.iii. for cancer, EPA has 
concluded that exposure to spirodiclofen from food and water will 
result in a lifetime cancer risk of 3 x 10-6 for the U.S. 
population.
    EPA generally considers cancer risks in the range of 
10-6 or less to be negligible. The precision which can be 
assumed for cancer risk estimates is best described by rounding to the 
nearest integral order of magnitude on the log scale; for example, 
risks falling between 3.16 x 10-7 and 3.16 x 10-6 
are expressed as risks in the range of 10-6. Considering the 
precision with which cancer hazard can be estimated, the 
conservativeness of low-dose linear extrapolation, and the rounding 
procedure described above, cancer risk should generally not be assumed 
to exceed the benchmark LOC of the range of 10-6 until the 
calculated risk exceeds approximately 3 x 10-6. Since the 
calculated cancer risk for spirodiclofen does not exceed this level, 
estimated cancer risk is considered to be negligible.
    5. Determination of safety. Based on these risk assessments, EPA 
concludes that there is a reasonable certainty that no harm will result 
to the general population, or to infants and children from aggregate 
exposure to spirodiclofen residues.

IV. Other Considerations

A. Analytical Enforcement Methodology

    Adequate enforcement methodology (a liquid chromatography (LC)/mass 
spectrometry (MS)/MS method) is available to enforce the tolerance 
expression. The method may be requested from: Chief, Analytical 
Chemistry Branch, Environmental Science Center, 701 Mapes Rd., Ft. 
Meade, MD 20755-5350; telephone number: (410) 305-2905; e-mail address: 
residuemethods@epa.gov.

B. International Residue Limits

    No maximum residue limits (MRLs) have been established by Canada, 
Mexico or Codex for spirodiclofen on hops.

V. Conclusion

    Therefore, a tolerance is established for residues of 
spirodiclofen, 3-(2,4-dichlorophenyl)-2-oxo-1-oxaspiro[4,5]dec-3-en-4-
yl 2,2-dimethylbutanoate, in or on hop, dried cones at 30 ppm.

VI. Statutory and Executive Order Reviews

    This final rule establishes tolerances under section 408(d) of 
FFDCA in response to a petition submitted to the Agency. The Office of 
Management and Budget (OMB) has exempted these types of actions from 
review under Executive Order 12866, entitled Regulatory Planning and 
Review (58 FR 51735, October 4, 1993). Because this rule has been 
exempted from review under Executive Order 12866, this rule is not 
subject to Executive Order 13211, Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use (66 FR 28355, 
May 22, 2001) or Executive Order 13045, entitled Protection of Children 
from Environmental Health Risks and Safety Risks (62 FR 19885, April 
23, 1997). This final rule does not contain any information collections 
subject to OMB approval under the Paperwork Reduction Act (PRA), 44 
U.S.C. 3501 et seq., nor does it require any special considerations 
under Executive Order 12898, entitled Federal Actions to Address 
Environmental Justice in Minority Populations and Low-Income 
Populations (59 FR 7629, February 16, 1994).
    Since tolerances and exemptions that are established on the basis 
of a petition under section 408(d) of FFDCA, such as the tolerance in 
this final rule, do not require the issuance of a proposed rule, the 
requirements of the Regulatory Flexibility Act (RFA) (5 U.S.C. 601 et 
seq.) do not apply.
    This final rule directly regulates growers, food processors, food 
handlers, and food retailers, not States or tribes, nor does this 
action alter the relationships or distribution of power and 
responsibilities established by Congress in the preemption provisions 
of section 408(n)(4) of FFDCA. As such, the Agency has determined that 
this action will not have a substantial direct effect on States or 
tribal governments, on the relationship between the national government 
and the States or tribal governments, or on the distribution of

[[Page 25539]]

power and responsibilities among the various levels of government or 
between the Federal Government and Indian tribes. Thus, the Agency has 
determined that Executive Order 13132, entitled Federalism (64 FR 
43255, August 10, 1999) and Executive Order 13175, entitled 
Consultation and Coordination with Indian Tribal Governments (65 FR 
67249, November 9, 2000) do not apply to this rule. In addition, This 
rule does not impose any enforceable duty or contain any unfunded 
mandate as described under Title II of the Unfunded Mandates Reform Act 
of 1995 (UMRA) (Public Law 104-4).
    This action does not involve any technical standards that would 
require Agency consideration of voluntary consensus standards pursuant 
to section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (NTTAA), Public Law 104-113, section 12(d) (15 U.S.C. 272 
note).

VII. Congressional Review Act

    The Congressional Review Act, 5 U.S.C. 801 et seq., generally 
provides that before a rule may take effect, the agency promulgating 
the rule must submit a rule report to each House of the Congress and to 
the Comptroller General of the United States. EPA will submit a report 
containing this rule and other required information to the U.S. Senate, 
the U.S. House of Representatives, and the Comptroller General of the 
United States prior to publication of this final rule in the Federal 
Register. This final rule is not a ``major rule'' as defined by 5 
U.S.C. 804(2).

List of Subjects in 40 CFR Part 180

    Environmental protection, Administrative practice and procedure, 
Agricultural commodities, Pesticides and pests, Reporting and 
recordkeeping requirements.

    Dated: April 24, 2008.
Donald R. Stubbs,
Acting Director, Registration Division, Office of Pesticide Programs.

0
Therefore, 40 CFR chapter I is amended as follows:

PART 180--[AMENDED]

0
1. The authority citation for part 180 continues to read as follows:

    Authority: 21 U.S.C. 321(q), 346a and 371.

0
2. Section 180.608 is amended by alphabetically adding the following 
commodity to the table in paragraph (a)(1) to read as follows:


Sec.  180.608  Spirodiclofen; tolerances for residues.

    (a) * * *.
    (1) * * *

------------------------------------------------------------------------
                      Commodity                        Parts per million
------------------------------------------------------------------------
                                * * * * *
Hop, dried cones.....................................                 30
                                * * * * *
------------------------------------------------------------------------

* * * * *
[FR Doc. E8-9826 Filed 5-6-08; 8:45 am]

BILLING CODE 6560-50-S
