Mesotrione; Pesticide Tolerance, 1508-1512 [E8-181]
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1508
Federal Register / Vol. 73, No. 6 / Wednesday, January 9, 2008 / Rules and Regulations
Dated: December 28, 2007.
Lois Rossi,
Director, Registration Division, Office of
Pesticide Programs.
[EPA–HQ–OPP–2006–0093]; FRL–8344–3]
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
https://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:
Kathryn V. Montague, Registration
Division (7505P), Office of Pesticide
Programs, Environmental Protection
Agency, 1200 Pennsylvania Ave., NW.,
Washington, DC 20460–0001; telephone
number: (703) 305–1243; e-mail address:
montague.kathryn @epa.gov.
SUPPLEMENTARY INFORMATION:
Mesotrione; Pesticide Tolerance
I. General Information
Parts per
million
Commodity
Therefore, 40 CFR chapter I is
amended as follows:
I
PART 180—[AMENDED]
1. The authority citation for part 180
continues to read as follows:
I
Authority: 21 U.S.C. 321(q), 346a and 371.
2. Section 180.475 is amended by
revising paragraph (a) to read as follows:
I
§ 180.475 Difenoconazole; tolerances for
residues.
(a) General. (1) Tolerances are
established for residues of the fungicide
difenoconazole, 1-[2-[2-chloro-4-(4chlorophenoxy)phenyl]-4-methyl-1,3dioxolan-2-ylmethyl]-1H-1,2,4-triazole,
in or on the following commodities:
Goat, meat ................................
Goat, meat byproduct (except
liver) ......................................
Hog, fat .....................................
Hog, liver ..................................
Hog, meat .................................
Hog, meat byproduct (except
liver) ......................................
Horse, fat ..................................
Horse, liver ...............................
Horse, meat ..............................
Horse, meat byproduct (except
liver) ......................................
Milk ...........................................
Sheep, fat .................................
Sheep, liver ...............................
Sheep, meat .............................
Sheep, meat byproduct (except
liver) ......................................
*
*
*
*
0.05
0.10
0.10
0.20
0.05
0.10
0.10
0.20
0.05
0.10
0.01
0.10
0.20
0.05
0.10
*
[FR Doc. E8–15 Filed 1–8–08; 8:45 am]
BILLING CODE 6560–50–S
Parts per
million
Commodity
Apple, wet pomace ...................
Banana1 ....................................
Barley, grain .............................
Barley, hay ................................
Barley, straw .............................
Beet, sugar ...............................
Beet, sugar, dried pulp .............
Canola, seed ............................
Corn, sweet, forage ..................
Corn, sweet, kernel plus cob
with husks removed ..............
Corn, sweet, stover ..................
Cotton, gin byproducts .............
Cotton, undelinted seed ...........
Fruit, pome group 11 ................
Grape1 ......................................
Papaya1 ....................................
Potato, processed waste ..........
Rye, grain1 ................................
Vegetable, fruiting, group 8 ......
Vegetable, tuberous and corm,
subgroup 1C .........................
1
4.5
0.2
0.1
0.05
0.05
0.01
1.9
0.01
0.01
0.01
0.01
0.05
0.05
1.0
0.10
0.30
0.04
0.1
0.60
0.01
There are no U.S. registrations.
(2) Tolerances are established for
residues of the fungicide
difenoconazole, 1-[2-[2-chloro-4-(4chlorophenoxy)phenyl]-4-methyl-1,3dioxolan-2-ylmethyl]-1H-1,2,4-triazole,
and its metabolite, CGA-205375, 1-[2chloro-4-(4-chloro-phenoxy)phenyl]-2[1,2,4]triazol-1-yl-ethanol, in or on the
following commodities:
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Commodity
Parts per
million
Cattle, fat ..................................
Cattle, liver ................................
Cattle, meat ..............................
Cattle, meat byproduct (except
liver) ......................................
Eggs ..........................................
Goat, fat ....................................
Goat, liver .................................
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0.10
0.20
0.05
0.10
0.10
0.10
0.20
Jkt 214001
ENVIRONMENTAL PROTECTION
AGENCY
40 CFR Part 180
Environmental Protection
Agency (EPA).
ACTION: Final rule.
AGENCY:
SUMMARY: This regulation establishes
tolerances for residues of mesotrione in
or on berry, group 13; flax, seed;
cranberry; lingonberry; millet, grain;
millet, forage; millet, hay; and millet,
straw. Syngenta Crop Protection
requested this tolerance under the
Federal Food, Drug, and Cosmetic Act
(FFDCA).
DATES: This regulation is effective
January 9, 2008. Objections and requests
for hearings must be received on or
before March 10, 2008, and must be
filed in accordance with the instructions
provided in 40 CFR part 178 (see also
Unit I.C. of the SUPPLEMENTARY
INFORMATION).
ADDRESSES: EPA has established a
docket for this action under docket
identification (ID) number EPA–HQ–
OPP–2006–0093. To access the
electronic docket, go to https://
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
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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), e.g., agricultural workers;
greenhouse, nursery, and floriculture
workers; farmers.
• Animal production (NAICS code
112), e.g., cattle ranchers and farmers,
dairy cattle farmers, livestock farmers.
• Food manufacturing (NAICS code
311), e.g., agricultural workers; farmers;
greenhouse, nursery, and floriculture
workers; ranchers; pesticide applicators.
• Pesticide manufacturing (NAICS
code 32532), e.g., agricultural workers;
commercial applicators; farmers;
greenhouse, nursery, and floriculture
workers; residential users.
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
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questions regarding the applicability of
this action to a particular entity, consult
the person listed under FOR FURTHER
INFORMATION CONTACT.
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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 https://
www.regulations.gov, you may access
this Federal Register document
electronically through the EPA Internet
under the ‘‘Federal Register’’ listings at
https://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 https://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–2006–0093 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 March 10, 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–2006–0093, by one of the
following methods:
• Federal eRulemaking Portal:
https://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
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Jkt 214001
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 April 26,
2006 (71 FR 24695) (FRL–8063–7), 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 6F7023) by
Syngenta Crop Protection, P.O. Box
18300, Greensboro, NC. The petition
requested that 40 CFR 180.571 be
amended by establishing tolerances for
residues of the herbicide mesotrione, 2–
[4- (methylsulfonyl)-2-nitrobenzoyl]-1,3cyclohexanedione, in or on flax, meal/
seed at 0.01 parts per million (ppm);
millet, forage/grain at 0.01 parts per
million (ppm); millet, hay/straw at 0.02
ppm; Berry group and cranberry at 0.01
ppm. That notice referenced a summary
of the petition prepared by Syngenta
Crop Protection, the registrant, which is
available to the public in the docket,
https://www.regulations.gov. There were
no comments received in response to
the notice of filing.
Based upon review of the data
supporting the petition, to harmonize
with the Food and Feed Commodity
Vocabulary (https://www.epa.gov/
opphed01/foodfeed/index.htm) EPA has
amended the commodity listing to read:
Flax, seed at 0.01 ppm; millet, grain at
0.01 ppm; millet, forage at 0.01 ppm;
millet, hay at 0.02 ppm; millet, straw at
0.02 ppm; berry, group 13 at 0.01 ppm,
lingonberry at 0.01 ppm and cranberry
at 0.02 ppm
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
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result to infants and children from
aggregate exposure to the pesticide
chemical residue....’’ These provisions
were added to FFDCA by the Food
Quality Protection Act (FQPA) of 1996.
Consistent with FFDCA section
408(b)(2)(D), and the factors specified in
FFDCA section 408(b)(2)(D), EPA has
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
tolerance for residues of mesotrione on
flax, seed at 0.01 ppm; millet, grain at
0.01 ppm; millet, forage at 0.01 ppm;
millet, hay at 0.02 ppm; millet, straw at
0.02 ppm; berry group 13 at 0.01 ppm,
lingonberry at 0.01 ppm and cranberry
at 0.02 ppm. EPA’s assessment of
exposures and risks associated with
establishing the tolerance 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. Specific
information on the studies received and
the nature of the adverse effects caused
by mesotrione as well as the noobserved-adverse-effect-level (NOAEL)
and the lowest-observed-adverse-effectlevel (LOAEL) from the toxicity studies
can be found at https://
www.regulations.gov. The referenced
document is available in the docket
established by this action, which is
described under ADDRESSES, and is
identified as ‘‘Mesotrione: Petition
6F7023 Human Health Risk Assessment
for Proposed Section 3 New Uses on
Berries, Cranberries, Millet, Flax, Grain
Sorghum (Section 18)’’ in that docket.
Additionally, mesotrione toxicological
data are discussed in the final rule
published in the Federal Register of
June 21, 2001 (66 FR 33187) (FRL–
6787–7).
B. Toxicological Endpoints
For hazards that have a threshold
below which there is no appreciable
risk, the toxicological level of concern
(LOC) is derived from 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) is sometimes
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used for risk assessment. Uncertainty/
safety factors (UFs) are used in
conjunction with the LOC 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 risks by comparing
aggregate 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 LOC by all
applicable UFs. Short-term,
intermediate-term, and long-term risks
are evaluated by comparing aggregate
exposure to the LOC to ensure that the
margin of exposure (MOE) called for by
the product of all applicable UFs is not
exceeded.
For non-threshold risks, the Agency
assumes that any amount of exposure
will lead to some degree of risk and
estimates risk in terms of the probability
of occurrence of additional adverse
cases. Generally, cancer risks are
considered non-threshold. For more
information on the general principles
EPA uses in risk characterization and a
complete description of the risk
assessment process, see https://
www.epa.gov/fedrgstr/EPA-PEST/1997/
November/Day–26/p30948.htm.
A summary of the toxicological
endpoints for mesotrione used for
human risk assessment can be found at
https://www.regulations.gov in document
‘‘Mesotrione: Petition 6F7023 Human
Health Risk Assessment for Proposed
Section 3 New Uses on Berries,
Cranberries, Millet, Flax, Grain
Sorghum (Section 18)’’ at page 16 in
docket ID number EPA–HQ–OPP–2006–
0093.
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C. Exposure Assessment
1. Dietary exposure from food and
feed uses. In evaluating dietary
exposure to mesotrione, EPA considered
exposure under the petitioned-for
tolerances as well as all existing
mesotrione tolerances in (40 CFR
180.571). EPA assessed dietary
exposures from mesotrione 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 mesotrione;
therefore, a quantitative acute dietary
exposure assessment is unnecessary.
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ii. Chronic exposure. In conducting
the chronic dietary exposure assessment
EPA used the food consumption data
from the United States Department of
Agriculutre (USDA) 1994–1996, and
1998 Nationwide Continuing Surveys of
Food Intake by Individuals (CSFII). As
to residue levels in food, EPA assumed
all foods for which there are tolerances
were treated and contain tolerance-level
residues.
iii. Cancer. Mesotrione was negative
for carcinogenicity in feeding studies in
rats and mice and was classified as ‘‘not
likely’’ to be a human carcinogen.
Therefore, a quantitative exposure
assessment to evaluate cancer risk is
unnecessary.
2. Dietary exposure from drinking
water. The Agency lacks sufficient
monitoring data to complete a
comprehensive dietary exposure
analysis and risk assessment for
mesotrione in drinking water. Because
the Agency does not have
comprehensive monitoring data,
drinking water concentration estimates
are made by reliance on simulation or
modeling taking into account data on
the environmental fate characteristics of
mesotrione. Further information
regarding EPA drinking water models
used in pesticide exposure assessment
can be found at https://www.epa.gov/
oppefed1/models/water/index.htm.
Based on the First Index Reservoir
Screening Tool (FIRST) for dry
harvested cranberry and a modified
Interim Rice Model for wet harvested
cranberry and Screening Concentration
in Ground Water (SCI-GROW) models,
the estimated environmental
concentrations (EECs) of mesotrione for
chronic exposures are estimated to be
4.7 parts per billion (ppb) for surface
water and 0.18 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 4.7 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 nonoccupational, non-dietary exposure
(e.g., for lawn and garden pest control,
indoor pest control, termiticides, and
flea and tick control on pets).
Mesotrione is not registered for use on
any sites 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
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‘‘available information’’ concerning the
cumulative effects of a particular
pesticide’s residues and ‘‘other
substances that have a common
mechanism of toxicity.’’
Mesotrione, pyrasulfotole,
isoxaflutole and topramezone belong to
a class of herbicides that inhibit the
liver enzyme 4-hydroxyphenylpyruvate
dioxygenase (HPPD), which is involved
in the catabolism (metabolic
breakdown) of tyrosine (an amino acid
derived from proteins in the diet).
Inhibition of HPPD can result in
elevated tyrosine levels in the blood, a
condition called tyrosinemia. HPPDinhibiting herbicides have been found to
cause a number of toxicities in
laboratory animal studies including
ocular, developmental, liver and kidney
effects. Of these toxicities, it is the
ocular effect (corneal opacity) that is
highly correlated with the elevated
blood tyrosine levels. In fact, rats dosed
with tyrosine alone show ocular
opacities similar to those seen with
HPPD inhibitors. Although the other
toxicities may be associated with
chemically-induced tyrosinemia, other
mechanisms may also be involved.
There are marked differences among
species in the ocular toxicity associated
with inhibition of HPPD. Ocular effects
following treatment with HPPD
inhibitor herbicides are seen in the rat
but not in the mouse. Monkeys also
seem to be recalcitrant to the ocular
toxicity induced by HPPD inhibition.
One explanation of this species-specific
response in ocular opacity may be
related to the species differences in the
clearance of tyrosine. A metabolic
pathway exists to remove tyrosine from
the blood that involves a liver enzyme
called tyrosine aminotransferase (TAT).
In contrast to rats where ocular toxicity
is observed following exposure to
HPPD-inhibiting herbicides, mice and
humans are unlikely to achieve the
levels of plasma tyrosine necessary to
produce ocular opacities because the
activity of TAT in these species is much
greater compared to rats. HPPD
inhibitors (e.g., nitisinone) are used as
an effective therapeutic agent to treat
patients suffering from rare genetic
diseases of tyrosine catabolism.
Treatment starts in childhood but is
often sustained throughout patient’s
lifetime. The human experience
indicates that a therapeutic dose (1
milligrams/kilogram/day (mg/kg/day)
dose) of nitisinone has an excellent
safety record in infants, children and
adults and that serious adverse health
outcomes have not been observed in a
population followed for approximately a
decade. Rarely, ocular effects are seen in
patients with high plasma tyrosine
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levels; however, these effects are
transient and can be readily reversed
upon adherence to a restricted protein
diet. This indicates that an HPPD
inhibitor in and of itself cannot easily
overwhelm the tyrosine-clearance
mechanism in humans.
Therefore, exposure to environmental
residues of HPPD-inhibiting herbicides
are unlikely to result in the high blood
levels of tyrosine and ocular toxicity in
humans due to an efficient metabolic
process to handle excess tyrosine. The
Agency continues to study the complex
relationships between elevated tyrosine
levels and biological effects in various
species. Nonetheless, as a worst case
scenario, EPA has assessed aggregate
exposure to mesotrione based on ocular
effects in rats. For similar reasons, a
semi-quantitative screening cumulative
assessment was conducted using the rat
ocular effects and 100% crop treated
information. The results of this
screening analysis did not indicate a
concern. In the future, assessments of
HPPD-inhibiting herbicides will
consider more appropriate models and
cross species extrapolation methods.
Therefore, EPA has not conducted
cumulative risk assessment with other
HPPD inhibitors. 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 https://
www.epa.gov/pesticides/cumulative.
D. Safety Factor for Infants and
Children
1. In general. Section 408 of FFDCA
provides that EPA shall apply an
additional (‘‘10X’’) tenfold 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. In applying this
provision, EPA either retains the default
value of 10X when reliable data do not
support the choice of a different factor,
or, if reliable data are available, EPA
uses a different additional FQPA safety
factor value based on the use of
traditional UFs and/or special FQPA
safety factors, as appropriate.
2. Prenatal and postnatal sensitivity.
There is quantitative evidence of
increased susceptibility of the young in
the oral prenatal developmental toxicity
studies in rats, mice, and rabbits and in
the multi-generation reproduction study
in mice and lack of a developmental
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neurotoxicity study in mice.
Quantitative evidence of increased
susceptibility was not demonstrated in
the multi-generation reproduction study
in rats. However, no NOAEL was
established for parental or offspring
systemic toxicity. There is evidence of
a qualitative increase in susceptibility
since the tyrosinemia observed in the
young was much more severe than that
observed in the adults.
3. Conclusion. There are 2
deficiencies in the mesotrione toxicity
database. First, a Developmental
Neurotoxicity Study has been required
to assess the effects on the developing
nervous/ocular system from exposed to
mesotrione. Second, the mouse 2–
generation reproduction study, on
which the Reference Dose/ Population
Adjusted Dose (RfD/PAD) is based failed
to identify a NOAEL. In light of this data
gap, the necessity of a reliance on a
LOAEL to calculate the RfD/PAD, and
the quantitative and qualitative
evidence of increased susceptibility of
the young discussed above, EPA is
raising the 10X FQPA safety factor to
the value of 30X.
E. Aggregate Risks and Determination of
Safety
Safety is assessed for acute and
chronic risks by comparing aggregate
exposure to the pesticide to the aPAD
and cPAD. The aPAD and cPAD are
calculated by dividing the LOC by all
applicable UFs. For linear cancer risks,
EPA calculates the probability of
additional cancer cases given aggregate
exposure. Short-term, intermediateterm, and long-term risks are evaluated
by comparing aggregate exposure to the
LOC to ensure that the MOE called for
by the product of all applicable UFs is
not exceeded.
1. Acute risk. There were no effects
observed in oral toxicity studies
including developmental toxicity
studies in rats and rabbits that could be
attributable to a single dose (exposure).
Therefore, mesotrione 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 exposure to mesotrione from food
and water will utilize 51% of the cPAD
for the population group (All Infants (<1
year old)). There are no residential uses
for mesotrione that result in chronic
residential exposure to mesotrione.
3. Short-term risk. Short-term
aggregate exposure takes into account
residential exposure plus chronic
exposure to food and water (considered
to be a background exposure level).
Mesotrione is not registered for use on
any sites that would result in residential
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1511
exposure. Therefore, the aggregate risk
is the sum of the risk from food and
water.
4. Intermediate-term risk
Intermediate-term aggregate exposure
takes into account residential exposure
plus chronic exposure to food and water
(considered to be a background
exposure level).
Mesotrione is not registered for use on
any sites that would result in residential
exposure. Therefore, the aggregate risk
is the sum of the risk from food and
water, which do not exceed the
Agency’s level of concern.
5. Aggregate cancer risk for U.S.
population. Mesotrione is classified as a
‘‘not likely’’ to be carcinogenic in
humans based on the results of a
carcinogenicity study in mice and the
combined chronic toxicity and
carcinogenicity study in the rat.
Therefore, mesotrione is not expected to
pose a cancer risk to humans.
6. 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 mesotrione
residues.
IV. Other Considerations
A. Analytical Enforcement Methodology
Adequate enforcement methodology
(high-pressure liquid chromatography
fluorescence detector (HPLC/FLD)) 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
There are no CODEX, Canadian, or
Mexican tolerances/Maximum Residue
Levels for mesotrione residues for the
proposed crops.
V. Conclusion
Therefore, the tolerance is established
for residues of mesotrione, 2-[4(methylsulfonyl)-2-nitrobenzoyl]-1,3cyclohexanedione, in or on flax, seed at
0.01 ppm; millet, grain at 0.01 ppm;
millet, forage at 0.01 ppm; millet, hay at
0.02 ppm; millet, straw at 0.02 ppm;
berry group 13 at 0.01 ppm, lingonberry
at 0.01 ppm and cranberry at 0.02 ppm.
VI. Statutory and Executive Order
Reviews
This final rule establishes a tolerance
under section 408(d) of FFDCA in
response to a petition submitted to the
Agency. The Office of Management and
E:\FR\FM\09JAR1.SGM
09JAR1
pwalker on PROD1PC71 with NOTICES
1512
Federal Register / Vol. 73, No. 6 / Wednesday, January 9, 2008 / Rules and Regulations
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
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 6, 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
VerDate Aug<31>2005
20:06 Jan 08, 2008
Jkt 214001
Transfer and Advancement Act of 1995
(NTTAA), Public Law 104–113, section
12(d) (15 U.S.C. 272 note).
VII. Congressional Review Act
List of Subjects in 40 CFR Part 180
Environmental protection,
Administrative practice and procedure,
Agricultural commodities, Pesticides
and pests, Reporting and recordkeeping
requirements.
Dated: December 28, 2007.
Lois Rossi,
Director, Registration Division, Office of
Pesticide Programs.
Therefore, 40 CFR chapter I is
amended as follows:
I
PART 180—[AMENDED]
1. The authority citation for part 180
continues to read as follows:
I
Authority: 21 U.S.C. 321(q), 346a and 371.
2. Section 180.571 is amended by
alphabetically adding the following
commodities in the table in paragraph
(a) to read as follows:
I
§ 180.571 Mesotrione; tolerances for
residues.
(a) * * *
Parts per million
Berry, group 13 ...............
*
*
*
Cranberry ........................
Flax, seed .......................
Lingonberry .....................
Millet, grain .....................
Millet, forage ...................
Millet, hay .......................
Millet, straw .....................
*
*
*
*
0.01
*
0.02
0.01
0.01
0.01
0.01
0.02
0.02
*
*
[FR Doc. E8–181 Filed 1–8–08; 8:45 am]
BILLING CODE 6560–50–S
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40 CFR Part 180
[EPA–HQ–OPP–2005–0268; FRL–8345–8]
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).
Commodity
ENVIRONMENTAL PROTECTION
AGENCY
Poly(hexamethylenebiguanide)
hydrochloride (PHMB); Exemption
from the Requirement of a Tolerance
Environmental Protection
Agency (EPA).
ACTION: Final rule.
AGENCY:
SUMMARY: This regulation establishes an
exemption from the requirement of a
tolerance for residues of the insecticide,
Poly(hexamethylenebiguanide)
hydrochloride (PHMB) on all food when
residues are the result of lawful
application of a food contact surface
sanitizer containing PHMB as a sanitizer
solution in food handling
establishments when applied as a
sanitizer. Arch Chemicals Inc.
submitted a petition to EPA under the
Federal Food, Drug, and Cosmetic Act
(FFDCA), as amended by the Food
Quality Protection Act of 1996 (FQPA),
requesting an exemption from the
requirement of a tolerance. This
regulation eliminates the need to
establish a maximum permissible level
for residues of PHMB.
DATES: This regulation is effective
January 9, 2008. Objections and requests
for hearings must be received on or
before March 10, 2008, and must be
filed in accordance with the instructions
provided in 40 CFR part 178 (see also
Unit I.C. of the SUPPLEMENTARY
INFORMATION.
EPA has established a
docket for this action under docket
identification (ID) number EPA–HQ–
OPP–2005–0268. To access the
electronic docket, go to https://
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 either in the electronic docket
at https://www.regulations.gov, or, if only
ADDRESSES:
E:\FR\FM\09JAR1.SGM
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Agencies
[Federal Register Volume 73, Number 6 (Wednesday, January 9, 2008)]
[Rules and Regulations]
[Pages 1508-1512]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E8-181]
-----------------------------------------------------------------------
ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[EPA-HQ-OPP-2006-0093]; FRL-8344-3]
Mesotrione; Pesticide Tolerance
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: This regulation establishes tolerances for residues of
mesotrione in or on berry, group 13; flax, seed; cranberry;
lingonberry; millet, grain; millet, forage; millet, hay; and millet,
straw. Syngenta Crop Protection requested this tolerance under the
Federal Food, Drug, and Cosmetic Act (FFDCA).
DATES: This regulation is effective January 9, 2008. Objections and
requests for hearings must be received on or before March 10, 2008, and
must be filed in accordance with the instructions provided in 40 CFR
part 178 (see also Unit I.C. of the SUPPLEMENTARY INFORMATION).
ADDRESSES: EPA has established a docket for this action under docket
identification (ID) number EPA-HQ-OPP-2006-0093. To access the
electronic docket, go to https://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 https://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: Kathryn V. Montague, Registration
Division (7505P), Office of Pesticide Programs, Environmental
Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-
0001; telephone number: (703) 305-1243; e-mail address:
montague.kathryn @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), e.g., agricultural
workers; greenhouse, nursery, and floriculture workers; farmers.
Animal production (NAICS code 112), e.g., cattle ranchers
and farmers, dairy cattle farmers, livestock farmers.
Food manufacturing (NAICS code 311), e.g., agricultural
workers; farmers; greenhouse, nursery, and floriculture workers;
ranchers; pesticide applicators.
Pesticide manufacturing (NAICS code 32532), e.g.,
agricultural workers; commercial applicators; farmers; greenhouse,
nursery, and floriculture workers; residential users.
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
[[Page 1509]]
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 https://
www.regulations.gov, you may access this Federal Register document
electronically through the EPA Internet under the ``Federal Register''
listings at https://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 https://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-2006-0093 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 March 10, 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-2006-0093, by one of the following methods:
Federal eRulemaking Portal: https://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 April 26, 2006 (71 FR 24695) (FRL-8063-
7), 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
6F7023) by Syngenta Crop Protection, P.O. Box 18300, Greensboro, NC.
The petition requested that 40 CFR 180.571 be amended by establishing
tolerances for residues of the herbicide mesotrione, 2-[4-
(methylsulfonyl)-2-nitrobenzoyl]-1,3-cyclohexanedione, in or on flax,
meal/seed at 0.01 parts per million (ppm); millet, forage/grain at 0.01
parts per million (ppm); millet, hay/straw at 0.02 ppm; Berry group and
cranberry at 0.01 ppm. That notice referenced a summary of the petition
prepared by Syngenta Crop Protection, the registrant, which is
available to the public in the docket, https://www.regulations.gov.
There were no comments received in response to the notice of filing.
Based upon review of the data supporting the petition, to harmonize
with the Food and Feed Commodity Vocabulary (https://www.epa.gov/
opphed01/foodfeed/index.htm) EPA has amended the commodity listing to
read: Flax, seed at 0.01 ppm; millet, grain at 0.01 ppm; millet, forage
at 0.01 ppm; millet, hay at 0.02 ppm; millet, straw at 0.02 ppm; berry,
group 13 at 0.01 ppm, lingonberry at 0.01 ppm and cranberry at 0.02 ppm
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....'' These provisions were added to FFDCA by the Food Quality
Protection Act (FQPA) of 1996.
Consistent with FFDCA section 408(b)(2)(D), and the factors
specified in FFDCA section 408(b)(2)(D), EPA has 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 tolerance
for residues of mesotrione on flax, seed at 0.01 ppm; millet, grain at
0.01 ppm; millet, forage at 0.01 ppm; millet, hay at 0.02 ppm; millet,
straw at 0.02 ppm; berry group 13 at 0.01 ppm, lingonberry at 0.01 ppm
and cranberry at 0.02 ppm. EPA's assessment of exposures and risks
associated with establishing the tolerance 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. Specific information on the studies received and the nature
of the adverse effects caused by mesotrione 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 https://
www.regulations.gov. The referenced document is available in the docket
established by this action, which is described under ADDRESSES, and is
identified as ``Mesotrione: Petition 6F7023 Human Health Risk
Assessment for Proposed Section 3 New Uses on Berries, Cranberries,
Millet, Flax, Grain Sorghum (Section 18)'' in that docket.
Additionally, mesotrione toxicological data are discussed in the final
rule published in the Federal Register of June 21, 2001 (66 FR 33187)
(FRL-6787-7).
B. Toxicological Endpoints
For hazards that have a threshold below which there is no
appreciable risk, the toxicological level of concern (LOC) is derived
from 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) is
sometimes
[[Page 1510]]
used for risk assessment. Uncertainty/safety factors (UFs) are used in
conjunction with the LOC 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 risks by
comparing aggregate 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 LOC by all applicable UFs.
Short-term, intermediate-term, and long-term risks are evaluated by
comparing aggregate exposure to the LOC to ensure that the margin of
exposure (MOE) called for by the product of all applicable UFs is not
exceeded.
For non-threshold risks, the Agency assumes that any amount of
exposure will lead to some degree of risk and estimates risk in terms
of the probability of occurrence of additional adverse cases.
Generally, cancer risks are considered non-threshold. For more
information on the general principles EPA uses in risk characterization
and a complete description of the risk assessment process, see https://
www.epa.gov/fedrgstr/EPA-PEST/1997/November/Day-26/p30948.htm.
A summary of the toxicological endpoints for mesotrione used for
human risk assessment can be found at https://www.regulations.gov in
document ``Mesotrione: Petition 6F7023 Human Health Risk Assessment for
Proposed Section 3 New Uses on Berries, Cranberries, Millet, Flax,
Grain Sorghum (Section 18)'' at page 16 in docket ID number EPA-HQ-OPP-
2006-0093.
C. Exposure Assessment
1. Dietary exposure from food and feed uses. In evaluating dietary
exposure to mesotrione, EPA considered exposure under the petitioned-
for tolerances as well as all existing mesotrione tolerances in (40 CFR
180.571). EPA assessed dietary exposures from mesotrione 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
mesotrione; 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 United States
Department of Agriculutre (USDA) 1994-1996, and 1998 Nationwide
Continuing Surveys of Food Intake by Individuals (CSFII). As to residue
levels in food, EPA assumed all foods for which there are tolerances
were treated and contain tolerance-level residues.
iii. Cancer. Mesotrione was negative for carcinogenicity in feeding
studies in rats and mice and was classified as ``not likely'' to be a
human carcinogen. Therefore, a quantitative exposure assessment to
evaluate cancer risk is unnecessary.
2. Dietary exposure from drinking water. The Agency lacks
sufficient monitoring data to complete a comprehensive dietary exposure
analysis and risk assessment for mesotrione in drinking water. Because
the Agency does not have comprehensive monitoring data, drinking water
concentration estimates are made by reliance on simulation or modeling
taking into account data on the environmental fate characteristics of
mesotrione. Further information regarding EPA drinking water models
used in pesticide exposure assessment can be found at https://
www.epa.gov/oppefed1/models/water/index.htm.
Based on the First Index Reservoir Screening Tool (FIRST) for dry
harvested cranberry and a modified Interim Rice Model for wet harvested
cranberry and Screening Concentration in Ground Water (SCI-GROW)
models, the estimated environmental concentrations (EECs) of mesotrione
for chronic exposures are estimated to be 4.7 parts per billion (ppb)
for surface water and 0.18 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 4.7 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).
Mesotrione is not registered for use on any sites 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.''
Mesotrione, pyrasulfotole, isoxaflutole and topramezone belong to a
class of herbicides that inhibit the liver enzyme 4-
hydroxyphenylpyruvate dioxygenase (HPPD), which is involved in the
catabolism (metabolic breakdown) of tyrosine (an amino acid derived
from proteins in the diet). Inhibition of HPPD can result in elevated
tyrosine levels in the blood, a condition called tyrosinemia. HPPD-
inhibiting herbicides have been found to cause a number of toxicities
in laboratory animal studies including ocular, developmental, liver and
kidney effects. Of these toxicities, it is the ocular effect (corneal
opacity) that is highly correlated with the elevated blood tyrosine
levels. In fact, rats dosed with tyrosine alone show ocular opacities
similar to those seen with HPPD inhibitors. Although the other
toxicities may be associated with chemically-induced tyrosinemia, other
mechanisms may also be involved.
There are marked differences among species in the ocular toxicity
associated with inhibition of HPPD. Ocular effects following treatment
with HPPD inhibitor herbicides are seen in the rat but not in the
mouse. Monkeys also seem to be recalcitrant to the ocular toxicity
induced by HPPD inhibition. One explanation of this species-specific
response in ocular opacity may be related to the species differences in
the clearance of tyrosine. A metabolic pathway exists to remove
tyrosine from the blood that involves a liver enzyme called tyrosine
aminotransferase (TAT). In contrast to rats where ocular toxicity is
observed following exposure to HPPD-inhibiting herbicides, mice and
humans are unlikely to achieve the levels of plasma tyrosine necessary
to produce ocular opacities because the activity of TAT in these
species is much greater compared to rats. HPPD inhibitors (e.g.,
nitisinone) are used as an effective therapeutic agent to treat
patients suffering from rare genetic diseases of tyrosine catabolism.
Treatment starts in childhood but is often sustained throughout
patient's lifetime. The human experience indicates that a therapeutic
dose (1 milligrams/kilogram/day (mg/kg/day) dose) of nitisinone has an
excellent safety record in infants, children and adults and that
serious adverse health outcomes have not been observed in a population
followed for approximately a decade. Rarely, ocular effects are seen in
patients with high plasma tyrosine
[[Page 1511]]
levels; however, these effects are transient and can be readily
reversed upon adherence to a restricted protein diet. This indicates
that an HPPD inhibitor in and of itself cannot easily overwhelm the
tyrosine-clearance mechanism in humans.
Therefore, exposure to environmental residues of HPPD-inhibiting
herbicides are unlikely to result in the high blood levels of tyrosine
and ocular toxicity in humans due to an efficient metabolic process to
handle excess tyrosine. The Agency continues to study the complex
relationships between elevated tyrosine levels and biological effects
in various species. Nonetheless, as a worst case scenario, EPA has
assessed aggregate exposure to mesotrione based on ocular effects in
rats. For similar reasons, a semi-quantitative screening cumulative
assessment was conducted using the rat ocular effects and 100% crop
treated information. The results of this screening analysis did not
indicate a concern. In the future, assessments of HPPD-inhibiting
herbicides will consider more appropriate models and cross species
extrapolation methods. Therefore, EPA has not conducted cumulative risk
assessment with other HPPD inhibitors. 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 https://www.epa.gov/pesticides/cumulative.
D. Safety Factor for Infants and Children
1. In general. Section 408 of FFDCA provides that EPA shall apply
an additional (``10X'') tenfold 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. In
applying this provision, EPA either retains the default value of 10X
when reliable data do not support the choice of a different factor, or,
if reliable data are available, EPA uses a different additional FQPA
safety factor value based on the use of traditional UFs and/or special
FQPA safety factors, as appropriate.
2. Prenatal and postnatal sensitivity. There is quantitative
evidence of increased susceptibility of the young in the oral prenatal
developmental toxicity studies in rats, mice, and rabbits and in the
multi-generation reproduction study in mice and lack of a developmental
neurotoxicity study in mice. Quantitative evidence of increased
susceptibility was not demonstrated in the multi-generation
reproduction study in rats. However, no NOAEL was established for
parental or offspring systemic toxicity. There is evidence of a
qualitative increase in susceptibility since the tyrosinemia observed
in the young was much more severe than that observed in the adults.
3. Conclusion. There are 2 deficiencies in the mesotrione toxicity
database. First, a Developmental Neurotoxicity Study has been required
to assess the effects on the developing nervous/ocular system from
exposed to mesotrione. Second, the mouse 2-generation reproduction
study, on which the Reference Dose/ Population Adjusted Dose (RfD/PAD)
is based failed to identify a NOAEL. In light of this data gap, the
necessity of a reliance on a LOAEL to calculate the RfD/PAD, and the
quantitative and qualitative evidence of increased susceptibility of
the young discussed above, EPA is raising the 10X FQPA safety factor to
the value of 30X.
E. Aggregate Risks and Determination of Safety
Safety is assessed for acute and chronic risks by comparing
aggregate exposure to the pesticide to the aPAD and cPAD. The aPAD and
cPAD are calculated by dividing the LOC by all applicable UFs. For
linear cancer risks, EPA calculates the probability of additional
cancer cases given aggregate exposure. Short-term, intermediate-term,
and long-term risks are evaluated by comparing aggregate exposure to
the LOC to ensure that the MOE called for by the product of all
applicable UFs is not exceeded.
1. Acute risk. There were no effects observed in oral toxicity
studies including developmental toxicity studies in rats and rabbits
that could be attributable to a single dose (exposure). Therefore,
mesotrione 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 exposure to
mesotrione from food and water will utilize 51% of the cPAD for the
population group (All Infants (<1 year old)). There are no residential
uses for mesotrione that result in chronic residential exposure to
mesotrione.
3. Short-term risk. Short-term aggregate exposure takes into
account residential exposure plus chronic exposure to food and water
(considered to be a background exposure level).
Mesotrione is not registered for use on any sites that would result
in residential exposure. Therefore, the aggregate risk is the sum of
the risk from food and water.
4. Intermediate-term risk Intermediate-term aggregate exposure
takes into account residential exposure plus chronic exposure to food
and water (considered to be a background exposure level).
Mesotrione is not registered for use on any sites that would result
in residential exposure. Therefore, the aggregate risk is the sum of
the risk from food and water, which do not exceed the Agency's level of
concern.
5. Aggregate cancer risk for U.S. population. Mesotrione is
classified as a ``not likely'' to be carcinogenic in humans based on
the results of a carcinogenicity study in mice and the combined chronic
toxicity and carcinogenicity study in the rat. Therefore, mesotrione is
not expected to pose a cancer risk to humans.
6. 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 mesotrione residues.
IV. Other Considerations
A. Analytical Enforcement Methodology
Adequate enforcement methodology (high-pressure liquid
chromatography fluorescence detector (HPLC/FLD)) 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
There are no CODEX, Canadian, or Mexican tolerances/Maximum
Residue Levels for mesotrione residues for the proposed crops.
V. Conclusion
Therefore, the tolerance is established for residues of mesotrione,
2-[4- (methylsulfonyl)-2-nitrobenzoyl]-1,3-cyclohexanedione, in or on
flax, seed at 0.01 ppm; millet, grain at 0.01 ppm; millet, forage at
0.01 ppm; millet, hay at 0.02 ppm; millet, straw at 0.02 ppm; berry
group 13 at 0.01 ppm, lingonberry at 0.01 ppm and cranberry at 0.02
ppm.
VI. Statutory and Executive Order Reviews
This final rule establishes a tolerance under section 408(d) of
FFDCA in response to a petition submitted to the Agency. The Office of
Management and
[[Page 1512]]
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 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 6, 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: December 28, 2007.
Lois Rossi,
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 180.571 is amended by alphabetically adding the following
commodities in the table in paragraph (a) to read as follows:
Sec. 180.571 Mesotrione; tolerances for residues.
(a) * * *
------------------------------------------------------------------------
Commodity Parts per million
------------------------------------------------------------------------
Berry, group 13...................................... 0.01
* * * * *
Cranberry............................................ 0.02
Flax, seed........................................... 0.01
Lingonberry.......................................... 0.01
Millet, grain........................................ 0.01
Millet, forage....................................... 0.01
Millet, hay.......................................... 0.02
Millet, straw........................................ 0.02
------------------------------------------------------------------------
* * * * *
[FR Doc. E8-181 Filed 1-8-08; 8:45 am]
BILLING CODE 6560-50-S