Document ID: EPA-HQ-OPP-2009-0141-0005
Agency: epa
Document Type: Rule
Title: Pesticide Tolerances: Aminopyralid
Posted Date: 2010-04-07T04:00Z

[Federal Register: April 7, 2010 (Volume 75, Number 66)]
[Rules and Regulations]               
[Page 17579-17584]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr07ap10-9]                         

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[EPA-HQ-OPP-2009-0141; FRL-8808-9]

 
Aminopyralid; Pesticide Tolerances

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes tolerances for residues of 
aminopyralid, including its metabolites and degradates, in or on corn, 
field, forage; corn, field, grain; and corn, field, stover. Dow 
AgroSciences requested these tolerances under the Federal Food, Drug, 
and Cosmetic Act (FFDCA).

DATES: This regulation is effective April 7, 2010. Objections and 
requests for hearings must be received on or before June 7, 2010, 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-2009-0141. All documents in the 
docket are listed in the docket index available at http://
www.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 Get Electronic Access to Other Related Information?

    You may access a frequently updated electronic version of EPA's 
tolerance regulations at 40 CFR part 180 through the Government 
Printing Office's e-CFR cite at http://www.gpoaccess.gov/ecfr. To 
access the OPPTS harmonized test guidelines referenced in this document 
electronically, please go to http://www.epa.gov/oppts and select ``Test 
Methods & Guidelines'' on the left-side navigation menu.

C. Can I File an Objection or Hearing Request?

    Under section 408(g) of FFDCA, 21 U.S.C. 346a, 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-2009-0141 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 June 7, 2010.
    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-2009-0141, 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 Facility'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 May 6, 2009 (74 FR 20947) (FRL-8412-7), 
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 8F7455) 
by Dow AgroSciences, 9330 Zionsville Rd., Indianapolis, IN 46268. The 
petition requested that 40 CFR 180.610 be amended by establishing 
tolerances for combined residues of the herbicide aminopyralid, 4-
amino-3,6-dichloro-2-pyridinecarboxylic acid, and its glucose 
conjugate, expressed as total parent, in or on corn, forage at 0.30 
parts per million (ppm); corn, grain at 0.20 ppm; and corn, stover at 
0.20 ppm. That notice referenced a summary of the petition prepared by 
Dow AgroSciences, the registrant, which is available to the public in 
the docket, http://www.regulations.gov. Comments were

[[Page 17580]]

received on the notice of filing. EPA's response to these comments is 
discussed in Unit IV.C.
    Based upon review of the data supporting the petition, EPA has 
revised the corn commodity terminology and tolerance expression for 
aminopyralid. The reasons for these changes are explained in Unit IV.D.

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 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 aminopyralid, including its metabolites and 
degradates, on corn, field, forage at 0.30 ppm; corn, field, grain at 
0.20 ppm; and corn, field, stover at 0.20 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.
    The toxicology database for aminopyralid includes toxicity studies 
conducted with the acid (XDE-750) and the triisopropanolammonium (TIPA) 
salt (GF-871). The acute toxicity data indicate that both the acid and 
salt have low toxicity via oral, dermal, and inhalation routes of 
exposure; and that neither is a skin irritant or skin sensitizer. The 
TIPA salt is not irritating to the eye; however, aminopyralid acid is 
severely irritating to the eye.
    Longer term studies indicate that the stomach, ileum, and cecum are 
targets for aminopyralid. In a subchronic feeding study in rats (XDE-
750), hyperplasia of the mucosal epithelium of the ileum and cecum was 
observed at the highest dose tested (HDT) of 1,000 milligrams/
kilograms/day (mg/kg/day). Chronic exposure in rats (XDE-750) also 
resulted in hyperplasia of the mucosal epithelium, along with cecal 
enlargement and decreased body weights at a lower dose of 500 mg/kg/
day. Hypertrophy and hyperplasia of the mucosal epithelium were seen 
after subchronic exposure in dogs (XDE-750) at the HDT of 929 mg/kg/
day. Thickening of the stomach mucosa (females), hyperplasia and 
hypertrophy of the mucosal epithelium, slight lymphoid hyperplasia of 
the gastric mucosa, and very slight/slight chronic mucosal inflammation 
were observed in dogs after chronic exposure at the HDT of 967 mg/kg/
day. No adverse effects were observed in subchronic or chronic feeding 
studies in mice.
    Stomach effects were also observed in a developmental toxicity 
study in rabbits conducted with the acid (XDE-750). Ulcers and erosions 
were seen in the glandular mucosa of the stomach at 500 mg/kg/day in 
maternal animals. Other effects noted were decreased body weights and 
incoordinated gait. No developmental effects were seen in fetuses at 
500 mg/kg/day. The high dose group was removed from the study because 
of the severity of the clinical signs that were observed (incoordinated 
gait, significant body weight losses, and decreased food intake). In 
another developmental rabbit study conducted with the TIPA salt (GF-
871), severe inanition (exhaustion from lack of food), body weight 
loss, decreased fecal output, and incoordinated gait were observed at 
260 mg/kg/day. At 520 mg/kg/day, decreased fetal body weights were 
observed. No effects were noted in developmental toxicity studies in 
rats with XDE-750 or GF-871 or a reproduction study in rats with XDE-
750. There was no qualitative or quantitative evidence of increased 
susceptibility of fetuses or offspring in any of the developmental and 
reproduction toxicity studies conducted with aminopyralid.
    No systemic toxic effects were observed in a 28-day dermal toxicity 
study in rats with XDE-750; however, dermal toxicity was indicated by 
slight epidermal hyperplasia in males at 1,000 mg/kg/day.
    In an acute neurotoxicity study in rats (XDE-750), fecal soiling in 
males and urine soiling in females were observed at 2,000 mg/kg/day. No 
adverse effects were observed in a chronic neurotoxicity study in rats 
up to 1,000 mg/kg/day.
    Aminopyralid is classified as ``not likely to be carcinogenic to 
humans.'' No increase in any tumors was found in carcinogenicity 
studies in rats and mice. Aminopyralid was negative in all mutagenicity 
studies, except for an in vitro chromosome aberration assay in Sprague 
Dawley rats. In this assay, XDE-750 induced chromosome aberrations, but 
only at cytotoxic concentrations. The clastogenic response was induced 
secondarily to toxicity.
    Specific information on the studies received and the nature of the 
adverse effects caused by aminopyralid 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 ``Aminopyralid. Human Health Risk 
Assessment for the Proposed Use on Field Corn (PP#8F7455)'' at page 40 
in docket ID number EPA-HQ-OPP-2009-0141.

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

[[Page 17581]]

aPAD and cPAD are calculated by dividing the POD by all applicable UFs. 
Aggregate short-, intermediate-, 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 aminopyralid used for 
human risk assessment can be found at http://www.regulations.gov in the 
document ``Aminopyralid: Human Health Risk Assessment for the Proposed 
Use on Field Corn (PP#8F7455)'' at page 20 in docket ID number EPA-HQ-
OPP-2009-0141.

C. Exposure Assessment

    1. Dietary exposure from food and feed uses. In evaluating dietary 
exposure to aminopyralid, EPA considered exposure under the petitioned-
for tolerances as well as all existing aminopyralid tolerances in 40 
CFR 180.610. EPA assessed dietary exposures from aminopyralid 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 aminopyralid; 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 U.S. Department 
of Agriculture (USDA) 1994-1996 and 1998 Continuing Survey of Food 
Intake by Individuals (CSFII). As to residue levels in food, EPA 
assumed that residues are present in all commodities at the tolerance 
level and that 100% of commodities are treated with aminopyralid. The 
Dietary Exposure Evaluation Model (DEEM)(tm) 7.81 default concentration 
factors were used to estimate residues of aminopyralid in processed 
commodities.
    iii. Cancer. Based on the results of carcinogenicity studies in 
rats and mice, EPA classified aminopyralid as ``not likely to be 
carcinogenic to humans.'' Therefore, an exposure assessment to evaluate 
cancer risk is unnecessary for this chemical.
    iv. Anticipated residue and percent crop treated (PCT) information. 
EPA did not use anticipated residue or PCT information in the dietary 
assessment for aminopyralid. Tolerance level residues and 100 PCT were 
assumed for all food commodities.
    2. Dietary exposure from drinking water. The Agency used screening 
level water exposure models in the dietary exposure analysis and risk 
assessment for aminopyralid in drinking water. These simulation models 
take into account data on the physical, chemical, and fate/transport 
characteristics of aminopyralid. 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 First Index Reservoir Screening Tool (FIRST) and 
Screening Concentration in Ground Water (SCI-GROW) models, the 
estimated drinking water concentrations (EDWCs) of aminopyralid for 
chronic exposures for non-cancer assessments (the only dietary exposure 
scenario of concern for aminopyralid) are estimated to be 1.937 parts 
per billion (ppb) for surface water and 0.63 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 1.937 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).
    Aminopyralid is currently registered for the following uses that 
could result in residential exposures: Natural recreation areas, such 
as wildlife management areas, campgrounds, trailheads and trails. EPA 
assessed residential exposure using the following assumptions:
    Aminopyralid is not applied by homeowners to residential or 
recreational settings; therefore, only post-application residential 
exposures were considered. A dermal endpoint of concern has not been 
identified for aminopyralid and postapplication inhalation exposure 
following treatment of recreation areas is expected to be negligible 
for adults and children. There is, however, the potential for short-
term postapplication oral exposure of children playing in areas treated 
with aminopyralid. EPA assessed the following incidental oral exposure 
scenarios: Hand-to-mouth transfer of residues; object-to-mouth transfer 
of residues; and ingestion of soil containing aminopyralid residues.
    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 aminopyralid to share a common mechanism of 
toxicity with any other substances, and aminopyralid does not appear to 
produce a toxic metabolite produced by other substances. For the 
purposes of this tolerance action, therefore, EPA has assumed that 
aminopyralid 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 Food Quality 
Protection Act Safety Factors (FQPA 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 aminopyralid includes harmonized guideline rat 
and rabbit developmental toxicity studies for both the acid and TIPA 
salt of aminopyralid and a two-generation reproduction toxicity study 
in rats conducted using aminopyralid acid. As discussed in Unit III.A 
(Toxicological Profile), there is no

[[Page 17582]]

quantitative or qualitative evidence of increased susceptibility of 
fetuses or offspring in any of these studies.
    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. That decision is based on the following 
findings:
    i. The toxicity database for aminopyralid is adequate to assess 
pre- and postnatal toxicity. In accordance with 40 CFR part 158 
Toxicology Data requirements, an immunotoxicity study (guideline 
870.7800) is required for aminopyralid. In the absence of specific 
immunotoxicity studies, EPA has evaluated the available aminopyralid 
data to determine whether an additional uncertainty factor is needed to 
account for potential immunotoxicity. The toxicology database for 
aminopyralid does not show any evidence of treatment-related effects on 
the immune system. The overall weight-of-evidence suggests that this 
chemical does not directly target the immune system, and the Agency 
does not believe that conducting a functional immunotoxicity study will 
result in a lower POD than that currently used for overall risk 
assessment. Therefore, a database uncertainty factor (UFDB) is not 
needed to account for the lack of this study.
    ii. No evidence of neurotoxicity was observed in acute or chronic 
neurotoxicity studies. Incoordinated gait, along with a lack of 
ambulatory movement, was observed in developmental toxicity studies 
(XDE-750 and GF-871) in rabbits at 500 mg/kg/day. However, the 
incoordination was transient (complete resolution within 2 hours 
postdosing) and considered to be a result of frank toxicity, rather 
than a neurotoxic event. Additionally, no signs of neurotoxicity were 
observed in other toxicity studies, and no evidence of quantitative or 
qualitative susceptibility was observed in developmental toxicity 
studies in rats or rabbits or a reproduction study in rats. Based on 
these findings, EPA has concluded that there is no need for a 
developmental neurotoxicity study or additional UFs to account for 
neurotoxicity.
    iii. There is no evidence that aminopyralid results in increased 
susceptibility in in utero rats or rabbits in the prenatal 
developmental studies or offspring in the 2-generation reproduction 
study.
    iv. There are no residual uncertainties identified in the exposure 
databases. The dietary food exposure assessments were performed based 
on 100 PCT and tolerance-level residues. EPA made conservative 
(protective) assumptions in the ground and surface water modeling used 
to assess exposure to aminopyralid in drinking water. EPA used 
similarly conservative assumptions to assess postapplication exposure 
of children as well as incidental oral exposure of toddlers. These 
assessments will not underestimate the exposure and risks posed by 
aminopyralid.

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-, intermediate-, 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, 
aminopyralid 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 
aminopyralid from food and water will utilize <1% of the cPAD for the 
general U.S. population and all population subgroups, including 
children 1 to 2 years old, the population group receiving the greatest 
exposure. Based on the explanation in Unit III.C.3., regarding 
residential use patterns, chronic residential exposure to residues of 
aminopyralid is not expected.
    3. Short-term risk. Short-term aggregate exposure takes into 
account short-term residential exposure plus chronic exposure to food 
and water (considered to be a background exposure level). Aminopyralid 
is currently registered for uses that could result in short-term 
residential exposure and the Agency has determined that it is 
appropriate to aggregate chronic exposure through food and water with 
short-term residential exposures to aminopyralid.
    Using the exposure assumptions described in this unit for short-
term exposures, EPA has concluded the combined short-term food, water, 
and residential exposures aggregated result in aggregate MOEs of 
between 25,000 and 33,000 for children's population subgroups. The 
aggregate MOEs include dietary exposures from food and drinking water 
as well as postapplication incidental oral exposure of children and 
toddlers playing in recreational areas treated with aminopyralid. 
Although short-term residential postapplication exposure of adults 
could result from the use of aminopyralid, inhalation exposures are 
expected to be negligible and a dermal endpoint of concern has not been 
identified for aminopyralid. Therefore, the short-term aggregate risk 
for adults is the sum of the risk from exposure to aminopyralid through 
food and water, which has already been addressed, and will not be 
greater than the chronic aggregate risk.
    4. Intermediate-term risk. Intermediate-term aggregate exposure 
takes into account intermediate-term residential exposure plus chronic 
exposure to food and water (considered to be a background exposure 
level). Aminopyralid is not registered for any use patterns that would 
result in intermediate-term residential exposure. Therefore, the 
intermediate-term aggregate risk is the sum of the risk from exposure 
to aminopyralid through food and water, which has already been 
addressed, and will not be greater than the chronic aggregate risk.
    5. Aggregate cancer risk for U.S. population. Based on a lack of 
evidence for carcinogenicity in mice and rats following long-term 
dietary administration, aminopyralid is not expected to pose a cancer 
risk.
    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 aminopyralid residues.

IV. Other Considerations

A. Analytical Enforcement Methodology

    Adequate enforcement methodology, Liquid Chromatography/Mass 
Spectrometry/Mass Spectrometry (LC/MS/MS), Method GRM 07.07, 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.

[[Page 17583]]

B. International Residue Limits

    No Codex, Canadian or Mexican MRLs have been established for corn 
commodities.

C. Response to Comments

    EPA received comments from an anonymous submitter objecting to 
pesticides and other ``toxic'' chemicals generally and recommending 
against any tolerances greater than zero for this product. The Agency 
understands the commenter's concerns and recognizes that some 
individuals believe that pesticides should be banned completely. 
However, the existing legal framework provided by section 408 of the 
FFDCA contemplates that tolerances greater than zero may be set when 
persons seeking such tolerances or exemptions have demonstrated that 
the pesticide meets the safety standard imposed by that statute. This 
submitter's comments appear to be directed at the underlying statute 
and not EPA's implementation of it; the citizen has made no contention 
that EPA has acted in violation of the statutory framework.

D. Revisions to Petitioned-For Tolerances

    EPA has revised the commodity terms ``corn, forage,'' ``corn, 
grain,'' and ``corn, stover,'' to read ``corn, field, forage,'' ``corn, 
field, grain,'' and ``corn, field, stover'' to agree with the Agency's 
Food and Feed Commodity Vocabulary.
    EPA is also revising the tolerance expression for existing 
tolerances and the new tolerances on corn commodities to clarify the 
chemical moieties that are covered by the tolerances and specify how 
compliance with the tolerances is to be measured. Plant tolerances are 
currently expressed in terms of ``free and conjugated residues of the 
herbicide aminopyralid, 2-pyridine carboxylic acid, 4-amino-3,6-
dichloro-, calculated as aminopyralid.'' Livestock tolerances are 
currently expressed in terms of ``residues of the herbicide 
aminopyralid.'' The tolerance expression for plants is being revised to 
make clear that the tolerances cover residues of aminopyralid, 4-amino-
3,6-dichloro-2-pyridinecarboxylic acid, including its metabolites and 
degradates. Compliance with the tolerances is to be determined by 
measuring only free and conjugated aminopyralid. Similarly, the 
tolerance expression for livestock commodities is being revised to 
clarify that the tolerances cover residues of aminopyralid, including 
its metabolites and degradates, but that compliance with the tolerance 
levels will be determined by measuring only aminopyralid.
    EPA has determined that it is reasonable to make these changes 
final without prior proposal and opportunity for comment, because 
public comment is not necessary, in that the changes have no 
substantive effect on the tolerances, but rather are merely intended to 
clarify the existing tolerance expressions.

V. Conclusion

    Therefore, tolerances are established for residues of aminopyralid, 
4-amino-3,6-dichloro-2-pyridinecarboxylic acid, including its 
metabolites and degradates, in or on corn, field, forage at 0.30 ppm; 
corn, field, grain at 0.20 ppm; and corn, field, stover at 0.20 ppm. 
Compliance with these tolerance levels is to be determined by measuring 
only free and conjugated aminopyralid.

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 final rule has been 
exempted from review under Executive Order 12866, this final rule is 
not subject to Executive Order 13211, entitled 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 9, 2000) do not apply to this final rule. In addition, 
this final 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: March 26, 2010.
Lois Rossi,
Director, Registration Division, Office of Pesticide Programs.

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

[[Page 17584]]

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 180.610 is amended by revising the introductory text in 
paragraphs (a)(1) and (a)(2) and alphabetically adding commodities to 
the table in paragraph (a)(1) to read as follows:

Sec.  180.610  Aminopyralid; tolerances for residues.

    (a) * * * (1) Tolerances are established for residues of the 
herbicide aminopyralid, 4-amino-3,6-dichloro-2-pyridinecarboxylic acid, 
including its metabolites and degradates, in or on the commodities in 
the table below. Compliance with the tolerance levels specified below 
is to be determined by measuring only free and conjugated aminopyralid.

----------------------------------------------------------------------------------------------------------------
                       Commodity                                            Parts per million
----------------------------------------------------------------------------------------------------------------
Corn, field, forage...................................                                                      0.30
Corn, field, grain....................................                                                      0.20
Corn, field, stover...................................                                                      0.20
                                                    * * * * *
----------------------------------------------------------------------------------------------------------------

    (2) Tolerances are established for residues of the herbicide 
aminopyralid, 4-amino-3,6-dichloro-2-pyridinecarboxylic acid, including 
its metabolites and degradates, in or on the commodities in the table 
below. Compliance with the tolerance levels specified below is to be 
determined by measuring only aminopyralid.
* * * * *

[FR Doc. 2010-7749 Filed 4-6-10; 8:45 am]
BILLING CODE 6560-50-S