penetration data. According to the commenter, accepting such data would
harmonize with requirements in the European Union (EU) and elsewhere.
The commenter pointed to well-established OECD guidelines for these
studies. The commenter also asserted that proposed test note 37 to the
proposed toxicology table in Sec.  158.2230, addressing the requirement
for a dermal absorption study, should not apply to corrosive/irritant
products.
    2. EPA's response. The Agency has, on a case-by-case basis, used in
vitro dermal absorption studies to determine the magnitude of dermal
absorption of pesticide chemicals. However, the Agency has not adopted
an official policy of using only in vitro data to support these
decisions. OECD guideline 428, while describing an in vitro method for
dermal absorption, does not rule out the use of in vivo data along with
in vitro data to determine dermal absorption. Further, the test
guideline notes that formal validation studies of the in vitro method
have not been performed.
    The Agency is working on developing a more formal policy that would
use both in vivo and in vitro dermal penetration data in a weight-of-
evidence (WOE) determination in appropriate cases. The Agency would
always consider QSAR or other models, submitted in support of the
determination of dermal absorption. The decision to accept such
information is the Agency's, based on its review and evaluation of the
submission.
    Test note 37 to the proposed toxicology table in Sec.  158.2230,
specifies that the trigger for requiring a dermal penetration study are
the results from a risk assessment ``assuming that dermal absorption is
equal to oral absorption.'' This means that EPA assumes 100 percent
dermal absorption. If a subchronic dermal study and/or dermal
absorption data are not available, then a risk assessment could be
conducted using the default assumption of equivalent absorption by the
dermal and oral routes of exposure. If unacceptable risks are found,
then either the subchronic dermal study or a dermal absorption study
would be required. EPA recognizes that the assumption of 100 percent
dermal absorption is conservative; however, this assumption would only
be used in the absence of an acceptable dermal subchronic study or
dermal absorption data. In this final rule, test note 37 to the
toxicology table in Sec.  158.2230(g), is revised to clarify this
process. EPA also agrees that corrosive/irritant products should not be
tested in dermal absorption studies. Therefore, test note 3 to the
toxicology table in Sec.  158.2230(g), which specifies that testing is
not needed for corrosive materials, is added as a trigger for not
requiring the dermal absorption study.

H. Tiering

    1. Comment. One commenter argued that EPA has not provided
meaningful tiering for its toxicology requirements for antimicrobials.
Another commenter claimed that exposure alone is not an appropriate
criterion to use for a tiered testing scheme, that both exposure and
risk should be considered. A third commenter asserted that the high and
low human exposure categories for toxicity are not appropriate and
suggested that a tiered scheme such as that used for environmental fate
data requirements would be more appropriate.
    2. EPA's response. In its proposed rule EPA proposed a tiered
testing scheme for toxicology testing that was based on the amount of
exposure as defined by use patterns. Based on its experience in
conducting risk assessments, EPA understands which use patterns have
exposures of higher duration and magnitude, and therefore could have
greater risks. Use patterns with higher exposures require submission of
more data than use patterns with lower exposures.

I. Guideline Numbers in the Code of Federal Regulations

    1. Comment. A commenter stated that the final rule should not
specify a guideline number. Instead, the data requirement tables should
describe the endpoint in question, and the information needed for EPA's
risk assessment. OPP could develop guidance that could be placed on the
web.
    2. EPA's response. The guideline number column could be removed
from the table. Instead, EPA could have an internet page that describes
multiple methods of fulfilling the data requirements. An internet table
could be updated faster to reflect newer techniques than rulemaking to
revise a regulation in the CFR. However, there is also value in having
the guideline number in the CFR, which then shows the available
guidelines relevant to the particular study that should be considered
in addressing the requirement. EPA has made no decision on whether or
not to initiate a rulemaking to remove all the guideline numbers from
the data requirement tables in 40 CFR part 158. The tables finalized in
subpart W in this rule include guideline numbers.

J. Animal Testing

    1. Comment. A commenter requested that EPA specifically state in
its regulations that non-animal methods are acceptable for fulfilling a
data requirement. The commenter argued that the Draize study (the acute
eye irritation study) in rabbits should be eliminated.
    2. EPA's response. Non-animal test methods are continually being
examined for use in fulfilling the toxicology data requirements that
are used to assess the hazard of pesticide chemicals. However, in order
for non-animal approaches to be used for fulfilling toxicology data
requirements, these approaches must first be scientifically validated
to ensure that they are as good as the existing test method for
predicting hazard and also assessed to determine whether they meet the
Agency's ``3 R'' goals of reduce, refine, and replace the use of
animals in testing. With respect to antimicrobial pesticides, the
Agency has started to explore such approaches. One example of this is
the voluntary pilot program for eye irritation testing of antimicrobial
pesticides using non-animal test methods, found at http://www.epa.gov/oppad001/eye-irritation.pdf.

K. Derivation of 200 Parts per Billion Criterion

    1. Comment. A commenter asked whether the 200 parts per billion
(ppb) level used as the dividing line between high and low human
exposures is the concentration of a substance in an adult's daily food
consumption?
    2. EPA's response. The derivation of the 200 ppb level was
previously established by FDA for indirect food use biocides
(identified in the docket by document ID number EPA-HQ-OPP-2008-0110-
0010). FDA derived the 200 ppb level by dividing the cumulative
exposure upper limit of 1,000 ppb for food contact substances by 5 to
account for the fact that antimicrobial pesticides (e.g., biocides) are
a class of pesticide that are generally toxic by design. The 200 ppb
level is the concentration of the antimicrobial residues in or on the
food item. EPA is using 200 ppb as a delineation consistent with the
FDA's

toxicology recommendations for food contact substances. Therefore,
those indirect food uses that have residues that are less than or equal
to 200 ppb in or on the food item usually have fewer data requirements
than those that have residues that are greater than 200 ppb in or on
the food item. For clarity, information concerning the 200 ppb level
and its derivation from FDA levels has been added to Sec.  158.2230(d).

L. Use of OECD Guidelines for EPA Registrations

    1. Comment. A commenter asked EPA to consider incorporating the
following OECD guidelines into the new part 158, subpart W to reduce
the number of animals killed in LD50 tests: OECD guidelines
436; Acute Inhalation Toxicity--Acute Toxic Class Method, and revised
223; Avian Acute Oral Toxicity Test, and Short Guidance on the
Threshold Approach for Acute Fish Toxicity.
    2. EPA's response. OPP does not have a policy for use of OECD 436
for acute inhalation toxicity. If a study conducted according to OECD
436 were submitted for the purpose of assessing acute inhalation
toxicity, EPA would review and accept the results if the study were
conducted in an acceptable manner and provided sufficient information
to fulfill the data requirement. Similarly, if a study conducted
according to OECD 223 or the Threshold Approach, were submitted, then
EPA would review the study and then make a determination on whether the
study was conducted in an acceptable manner and provided sufficient
information to fulfill the data requirement.

M. Alternative Formats for Toxicology Data Requirements Table

    1. Comment. In the comments submitted to EPA, the commenters
suggested two alternative toxicity data requirement approaches for EPA
to consider. Alternative approach 1 was organized in paragraphs and
alternative approach 2 was in a table format similar to that proposed
by EPA.
    2. EPA's response. The commenters provided two alternative
approaches for toxicology data requirements for antimicrobials. As
stated by the commenter, alternative approach 1 was ``intended to
provide clearer instructions to registrants,'' attempted ``to fully
incorporate the new science'' of integrative approaches to testing, and
included ``a threshold concept for toxicological concerns.'' (ACC
Comment, identified in the docket by document ID number EPA-HQ-OPP-
2008-0110-0088.6; Appendix E, entitled ``Comments on Proposed Data
Requirements for Toxicology'' p. 24). The commenter did not provide to
EPA the same or similar table-type of format used for part 158 data
requirements. There were no test notes to define the triggers for
moving from tier to tier. The commenter acknowledged that their
suggested alternative approach 1 would require ``expert scientific
judgment'' (p. 25), and also discussed that EPA in the proposed rule
(73 FR 59423) had indicated the need to develop scientific position
papers, and recommendations for internal and external review of
integrative approaches. EPA considers alternative approach 1 to be a
dramatic departure from EPA's proposal, and agrees with the commenter
that certain scientific issues may not be ready for codification. EPA
does not believe, at this time, that this approach meets the needs of
the Agency, or has any advantages over the table format. EPA found the
paragraph explanations unclear. As acknowledged by the commenter, the
paragraph format would result in a more complex decision tree that
would require a significantly greater amount of interpretation and
consultation when compared to the existing table formats. There would
be a significant learning curve for both EPA and those members of the
public that have become accustomed to data requirement tables such as
in part 158. Within this response, EPA has responded to alternative
approach 1 in totality. EPA notes that the individual scientific issues
raised within the paragraphs are addressed separately, as they were
separated into the various disciplinary areas of the toxicology
comments.
    EPA has also evaluated alternative approach 2. This alternative
approach is in a table-type of format with a strict split between food
and nonfood uses. The test notes developed by the commenters are
extremely detailed and contain information that EPA believes is more
appropriate in guidance. However EPA has used the suggested test notes
to revise the test notes in this final rule as appropriate. For
example, the commenters' suggested test note 32 to the in vivo
cytogenetics study is clearer than EPA's proposed test note 34.
Therefore EPA is revising test note 34 to the final toxicology table in
Sec.  158.2230(g), accordingly.
    As discussed previously, as a result of comments received, EPA is
no longer using the terms ``high human exposure'' and ``low human
exposure'' as proposed for the antimicrobial toxicology data
requirements table. Instead, in the final rule, EPA is now using a
food/nonfood approach with some similarities to that of the toxicology
data requirements table for conventional pesticides to distinguish the
use patterns with higher exposure that need more toxicity data from
those that need less. Accordingly, the table headers for the toxicology
data requirements table in the final rule are: ``Direct Food Uses;''
``Indirect Food Uses (>200 ppb);'' ``Indirect Food Uses (<=200 ppb);''
``Swimming Pools, Aquatic Areas, Wood Preservatives, Metal Working
Fluids;'' and ``All Other Nonfood Uses.''
    Unlike conventional pesticide chemicals, a strict food/nonfood use
``split'' for delineating data requirements is not appropriate for
antimicrobial chemicals. Such an approach does not fully address the
unique use patterns for antimicrobials, most specifically, those
involving indirect food uses. As a result of comments received, EPA
decided to employ a modification of the food/nonfood approach to
delineate the specific data requirement needs for antimicrobial
pesticides.
    The commenter has also asked that EPA include within subpart W a
new Sec.  158.2235 which would be analogous to 40 CFR 158.510 for
conventional chemicals (Tiered Testing Options for Nonfood Use
Pesticides). EPA does not believe this is needed for antimicrobials.
Once it has been determined that the use is nonfood, then certain of
the nonfood use scenarios require the submission of more data, and
certain require the submission of less data. As specified in the column
headings for Nonfood Uses, swimming pools, aquatic areas, wood
preservatives, and metal working fluids require a particular set of
data. All other nonfood uses require less data. Thus, the tiering is
already built into the approach used for antimicrobials.

XI. Nontarget Organism Data Requirements

    The following represent the significant comments received on the
need for and evaluation of nontarget organism studies as proposed by
EPA. Changes from the proposed rule to the final rule are also
described. A more detailed discussion can be found in the Response to
Comments Document available in the docket to this rule.

A. Need for Ecotoxicity Data for Indoor Uses

    1. Comment. Several commenters argued that there are few
antimicrobial use patterns where ecological effects information would
be relevant to an assessment under FIFRA because there is no
expectation of environmental exposure.

    2. EPA's response. As explained in the proposed rule, there is now
a greater concern regarding indoor uses of antimicrobials because those
uses can lead to environmental exposure when they go down the drain.
The Agency and the scientific community have become concerned with
pharmaceuticals and personal care products (PPCPs), which are now
recognized as environmental contaminants. A subset of these PPCPs
includes antimicrobial pesticide products, some of which are being
detected in various environmental compartments/media [e.g., surface
water and WWTP biosolids]. As discussed in the proposed rule (73 FR
59407), these findings are notable, because many of the antimicrobial
pesticides detected are registered for only indoor use patterns.
    There are many uses for which a high potential for environmental
exposure exists, especially outdoor uses such as wood preservatives,
ballast water treatments, antifoulant paints and coatings, aquatic
areas, and others. These uses may require a more extensive data set
that could include acute and chronic tests in both freshwater and
saltwater, and possibly in the sediment as well as the water column. If
the effluent from a WWTP is likely to contain an antimicrobial
pesticide, or if the antimicrobial is likely to partition to the sludge
that is derived during the treatment process, then indoor uses could
require additional testing to further characterize the hazard and the
risk.

B. Transformation Products

    1. Comment. Several commenters questioned, how a registrant would
determine if ``transformation products'' would need to be tested. With
regard to the criteria for when testing is required on transformation
products, another commenter stated the belief that any data developed
to assess the potential risk to nontarget organisms should be developed
with the appropriate residue of concern (ROC) (i.e., degradation
product, metabolite, or TGAI) rather than always testing with the TGAI.
Still another commenter asked how would EPA determine that the
transformation products are ``more toxic, persistent, bioaccumulative
or have been shown to cause adverse effects in mammalian or aquatic
reproductive studies.'' Finally, a commenter requested that EPA explain
what is considered ``stable'' in the environment in proposed test note
3 to the proposed nontarget organism table in Sec.  158.2240.
    2. EPA's response. The Agency evaluates the need for nontarget
organism testing of transformation products on a case-by-case basis,
using several sources of information, which includes, most importantly,
environmental fate data. EPA proposed to require nontarget organism
testing of transformation/degradation products or leachate residues in
proposed Sec.  158.2240(a)(3) and (4). To respond to this comment, EPA
also considered a similar comment on transformation/degradation
products or leachate residues for environmental fate testing (see Unit
XIV.B.). In response to these comments, EPA determined to clarify and
revise the criteria for testing of transformation/degradation products
and leachate residues for nontarget organisms in Sec.  158.2240(a)(3),
for environmental fate in Sec.  158.2280(a)(2) and for nontarget plant
protection in Sec.  158.2250(b).
    As explained in Unit XIV.B., environmental fate studies provide
information on the stability and persistence of the active ingredient
and degradation products in the various environmental media. If the
environmental fate studies on the parent indicate the transformation/
degradation product(s) is, for example, more persistent in soils, then
it is possible that nontarget plants or animals could be exposed to the
degradate. Once the transformation products and the environmental
compartment in which they occur are identified, then the available
toxicology data (e.g., reproduction tests, developmental tests, non-
rodent chronic studies) are reviewed to determine toxicity.
    After reviewing all available information, then EPA would use these
criteria to determine if ecological effects data on the transformation/
degradation products or leachate residues are required for either
nontarget organisms or nontarget plants. EPA believes that nontarget
plant protection data may sometimes be needed when the Agency begins
conducting species-specific endangered species assessments for
antimicrobial pesticides.
    EPA does not use the term ``residue of concern (ROC)'' in the final
Nontarget Organisms Data Requirements Table. Instead, the appropriate
test material(s), such as TGAI, degradate, or TEP, is specified in the
data requirements table in Sec.  158.2240. This approach is also used
for the conventional nontarget organism table in part 158. Generally,
for ecological testing, the TGAI testing is performed first, and then
additional testing on a transformation product may be required based on
the process described previously. Depending on how fast a substance
decays, a nontarget organism or plant could actually be exposed to a
mixture of the parent and one or more degradation/transformation
products.

C. Test Note 7 to the Nontarget Organism Table and Wood Preservatives

    1. Comment. Test note 7 to the proposed nontarget organism data
requirements table in Sec.  158.2240 specifies the triggers for
requiring typical end-use product (TEP) testing for the acute
freshwater invertebrate study and acute freshwater fish study. A
commenter asked whether, even though, the wood preservatives use
pattern is specified as ``NR,'' could the TEP testing be required
because of the triggers in test note 7.
    2. EPA's response. Proposed test note 7 also triggered the testing
for the TEP acute estuarine and marine organisms toxicity testing. EPA
agrees that the combination of ``R''s, ``CR''s, ``NR''s and the current
structure of proposed test note 7, is confusing and that clarification
is needed.
    The data requirements for TEP testing and proposed test note 7 were
also considered in light of the Agency's determination based on
comments received (see Unit VI.B.) on EPA's current practice of
conducting risk assessments for wood preservatives based on land-only
versus a land and aquatic predetermined use pattern. All wood
preservative risk assessments will now be performed considering that
the treated wood could end-up on both the land or in the aquatic
environment. As previously discussed, there are multiple pathways for
wood preservative degradates and/or leachates to reach surface water.
EPA has also determined to conduct a down-the-drain assessment for all
appropriate use patterns which would include wood preservatives, and
antifoulant paints and coatings (see Unit XV.A.). For wood
preservatives, these determinations mean that additional ecological
testing is required to conduct an ecological risk assessment, and the
following changes are made to the wood preservative testing column:
     Acute freshwater invertebrates toxicity (TEP testing):
change from ``NR'' to ``CR'';
     Acute freshwater fish toxicity (TEP testing): change from
``NR'' to ``CR'';
     Acute estuarine and marine organisms toxicity (TEP
testing): change from ``NR'' to ``CR''.
    For antifoulant paints and coatings, the determination to conduct
assessment also means that additional data could be needed for the
down-the-drain assessment, and the following changes have been made to
the antifoulant paints and coatings testing column:

     Acute freshwater invertebrates toxicity (TEP testing):
change from ``NR'' to ``CR'';
     Acute freshwater fish toxicity (TEP testing): change from
``NR'' to ``CR'';
     Acute estuarine and marine organisms toxicity (TEP
testing): change from ``NR'' to ``CR''.
    EPA believes that simplifying the data requirements that reference
test note 7 to the final nontarget organism table in Sec.  158.2240(c)
so that these requirements are CR for all use patterns is clearer, and
also closer to the suggestions made by the commenters in their
suggested nontarget organism data requirements table. Their suggested
table was predominantly ``CR'' for aquatic uses. Therefore, in this
final rule, test note 7 triggers the ``CR'' studies.
    However, changing all the use patterns to ``CR'' for the TEP
studies means changing the ``R'' proposed for the aquatic use, and
industrial processes and water systems use patterns for the acute
freshwater invertebrates toxicity study and the acute freshwater fish
toxicity study, to ``CR.'' To account for this change proposed test
note 7 to the proposed nontarget organism table in Sec.  158.2240 has
been revised in the final rule to include an additional trigger (see
Sec.  158.2240(d) test note 7.iv). Data are required when ``the end-use
antimicrobial product will be applied directly into an aquatic
environment.'' EPA believes that the implications of this trigger are
equivalent to the ``R'' and essentially this is a non-change. These
changes are summarized here for both the aquatic areas and industrial
processes and water systems testing column:
     Acute freshwater invertebrates toxicity (TEP testing):
change from ``R'' to ``CR'';
     Acute freshwater fish toxicity (TEP testing): change from
``R'' to ``CR'';
     Acute estuarine and marine organisms toxicity (TEP
testing): no change.
    Nontarget organism toxicity testing of the TEP should be
infrequently required for the antifoulant paints and coatings use
pattern because for this use pattern, the TEP could be the paint.
Because the testing for aquatic organisms is done in water, the test
material must be soluble in water, or made soluble by addition of an
appropriate solvent, if one exists, or other appropriate mechanical
methods. Paint is not soluble and there may not be a way to make it
soluble. Since these studies are often run in glass aquaria, the paint
could coat the sides of the glass and the test animals themselves. The
paint could ruin test equipment by clogging lines and injection
nozzles. Therefore EPA has added a new test note 5, which is replacing
proposed test note 5 to the proposed nontarget organism in Sec.
158.2240. New test note 5 to the final nontarget organism table in
Sec.  158.2240(c) states that an applicant should request a waiver if
the TEP cannot be tested.
    EPA also notes that a test note specifying the number of species to
be tested was omitted in the proposed rule for the TEP testing for
acute freshwater fish toxicity. This test note is needed for clarity.
Test note 3 to the final nontarget organism table in Sec.  158.2240(c)
has been added to the line for acute freshwater fish toxicity. Instead
of ``greater than 1 ppm or 1 mg/L'' as indicated in the proposed rule,
the toxicity trigger has been corrected to read ``less than or equal to
1 ppm or 1 mg/L.'' If the LC50 is greater than 1 ppm this
means that the chemical tested was moderately to practically non-toxic
on an acute basis. If the LC50 is less than 1 ppm this means
that the chemical tested was highly to very highly toxic on an acute
basis and would have a serious adverse affect(s) on the organism tested
at low concentrations. For clarity, in test note 3 to the nontarget
organism table, EPA has specified the appropriate trigger (less than or
equal to) to indicate that testing is needed for chemicals that
demonstrate high to very high toxicity on an acute basis.

D. Acute and Chronic Toxicity Data

    1. Comment. A commenter argued that it is essential to have both
acute and chronic toxicity test results for at least one freshwater
invertebrate, vertebrate, and plant species, and at least one marine/
estuarine invertebrate, vertebrate, and plant species.
    2. EPA's response. EPA proposed to require acute tests for both a
cold water and warm water freshwater fish, an invertebrate, and one or
more aquatic plants. For marine/estuarine species, for most use
patterns, EPA proposed to conditionally require acute testing with a
fish and two aquatic invertebrate species, including a bivalve, when
the Agency believes there is a potential for the active ingredient or a
potentially toxic degradate to reach the estuarine/marine environment
through transport (e.g., leaching, runoff) from the treatment site. In
such a situation, chronic testing with one or more marine/estuarine
species also may be required if the Agency believes that chronic
exposure is likely. These studies also are required for those uses
where the pesticide product is applied directly into the marine/
estuarine environment.
    As to chronic testing, EPA proposed to require the fish early life
stage and the aquatic invertebrate life-cycle studies for the
industrial processes and water systems (once-through), antifoulant
coatings and paints, and aquatic areas use patterns. At that time, EPA
also proposed to conditionally require the same two studies for the low
environmental grouping (now called the all other use patterns category)
and wood preservatives.
    However, based on this and other comments, EPA has reevaluated the
nontarget organism data needed for a registration decision and
concluded that additional acute and chronic data are needed. Plant
species encompass many different life spans. Phytoplankton reproduce
quickly and have extremely short life spans. Annuals live for 1 year.
Many perennials do not actually live for multiple years, but reproduce
from seeds year after year. The plant species that live the longest
would be woody species, such as trees. EPA does not believe that
antimicrobial use patterns impact terrestrial areas such that chronic
exposures occur. To EPA's knowledge, no adverse chronic effects to
terrestrial plants caused by pesticides have been documented on plants.
Any effect on terrestrial plant species has been categorized as an
acute effect and would be covered by current testing procedures.
Chronic effects of aquatic plants are covered by the aquatic testing
guidelines. Algae are used as the primary test species for evaluating
effects to the aquatic plants. The testing is based on growth
parameters and the tests normally run for periods of time that would
include several generations of the algae. The results from these algal
studies, while only conducted over a few days, would be similar to
those obtained from chronic testing in other species, and would be used
to assess any chronic effects to aquatic plant species.

E. Avian Studies

    1. Comment. In proposed test note 4 to the proposed nontarget
organism table in Sec.  158.2240, which triggers the avian dietary
study, EPA specified a trigger of 100 mg a.i./kg (milligrams active
ingredient/kilogram) for additional testing. A commenter requested
information on why this trigger was selected. The commenter also
claimed that EPA could use exposure tools to conduct an initial
assessment based on Tier I data, and then trigger additional testing
based on risk.
    2. EPA's response. OPP has long used this value as an indication of
toxicity to birds. As specified in 40 CFR 156.85(b)(3), any pesticide
(including conventional pesticides) that is

intended for outdoor use with an avian acute oral LD50 of
100 mg a.i./kg or less requires a precautionary label statement that
the pesticide is toxic to birds. EPA believes that if 100 mg a.i./kg is
appropriate to trigger a precautionary label statement, then it is also
appropriate to use as a trigger for testing. Therefore, if the avian
oral acute toxicity study indicates an oral LD50 of 100 mg
a.i./kg or less, then an avian dietary study is required.
    In the proposed rule, for the avian dietary toxicity study, EPA
proposed to require testing on two species for the aquatic areas and to
conditionally require testing on one avian species for all of the other
use patterns. The comments reviewed and evaluated by EPA on avian
toxicity testing included the commenter's suggested data requirements
table for nontarget organisms, which specified ``CR'' for all avian
testing. EPA agrees with the commenter that ``CR'' is appropriate for
the avian dietary toxicity and avian reproduction studies for all use
patterns. This simplifies the test notes and with the appropriate
triggers EPA would be able to require the needed testing.
    The following changes have been made to the aquatic areas column:
     Avian dietary toxicity: change from ``R'' to ``CR'';
     Avian reproduction: change from ``R'' to ``CR''.
    Test note 4 to the final nontarget organism table in Sec.
158.2240(c) triggers the avian dietary toxicity study based on the
results of the avian acute toxicity study. For the avian dietary study,
testing in a second species would be triggered based on the results of
the avian dietary testing in the first species. Since the second test
species will be required, based on the results of the first species,
proposed test note 5 is no longer needed and is being removed. Test
note 6 to the final nontarget organism table in Sec.  158.2240(c) would
trigger the avian reproductive study based on one or more of four
specific criteria. There were no revisions to these criteria from the
proposed rule to the final rule.

F. Water Quality Criterion

    1. Comment. A commenter argued that the registrants of any
antimicrobial pesticide that has the potential to be discharged either
directly or indirectly to surface water should be required to supply
any additional data needed to derive a water quality criterion for the
pesticide in question.
    2. EPA's response. As discussed in the conventionals' Response to
Comments Document in docket EPA-HQ-OPP-2004-0387 (p. 104), the Agency's
pesticide registration process, including its data requirement
regulations, adequately considers the endpoints that are protected
under the Clean Water Act (CWA) as administered by the Office of Water
(OW). When acceptable data are available, OPP uses these data in its
risk assessment process.
    The purpose of a water quality criterion under the CWA is to
determine the level at which a water body may be at risk for
environmental damage. The purpose of certain data requirements for
pesticide registration is to allow the Agency to determine the
ecological risk of using a pesticide. Thus, these program offices
within EPA have similar goals. While EPA has developed guidelines for
developing Water Quality Criteria (WQC), the Agency has also recognized
that WQC can be developed with a more limited data set.
    Pesticide registration data are valuable in assessing water quality
risks. As noted in EPA's 2005 Response to Comments Document on the
conventional pesticides, EPA's OW and OPP together developed aquatic
life benchmarks for 71 pesticides or pesticide degradation products for
States to use to establish targets for safe levels of pesticides for
aquatic plants and animals. The benchmarks are derived from data
submitted to EPA for pesticide registration. As of April 18, 2011,
there are 242 pesticide chemicals with aquatic benchmarks on EPA's Web
site (http://www.epa.gov/oppefed1/ecorisk_ders/aquatic_life_benchmark.htm).

G. Sediment Testing

    1. Comment. The commenter asserted that EPA did not consider the
environmental fate of a compound (such as the tendency of a chemical to
absorb/desorb) when considering the need for sediment testing.
    2. EPA's response. EPA disagrees with this comment. Test notes 17
and 18 to the final nontarget organism table in Sec.  158.2240(c)
trigger the sediment studies based on the results of the aerobic soil
or aquatic metabolism studies and knowledge of the physical/chemical
properties which express the environmental fate of the antimicrobial
pesticide chemical. The soil partition coefficient (Kd) is
used as an expression of the binding capability of the chemical to
sediments. The Agency's justification for using Kd [gteqt]
50 as a criterion for requiring sediment testing is that this value
would capture those chemicals with about 80 percent adsorption to
sediments (relative to organic carbon).
    The octanol-water partition coefficient (Kow) and the
soil organic carbon-water partition coefficient (Koc) also
are used by EPA as part of its decision process. Both values are
frequently more available than either the Kd or half-life
values. Test note 17, the trigger for requiring an acute sediment
study, considers all four of these values.
    Next, as explained in test note 18, the chronic sediment study is
triggered based on the results of the acute sediment study as well as a
reexamination of the Kow, Koc, and Kd.

XII. Nontarget Plant Protection Data Requirements

    The following represent the significant comments on the need for
and evaluation of nontarget plant protection studies as proposed by
EPA. The changes from the proposed rule to final rule are also
described. A more detailed discussion can be found in the Response to
Comments Document available in the docket to this rule.

A. Triggers for Higher-Tiered Plant Studies

    1. Comment. One commenter asked EPA to explain the criteria used to
trigger higher-tiered plant studies based on the results of the algal
studies.
    2. EPA's response. The criteria to trigger higher-tiered plant
studies are specified in test notes 2 and 5 to the proposed nontarget
plant protection table in Sec.  158.2250. A toxicity level
(EC50 < 1 ppm) indicates that the antimicrobial pesticide
would have serious adverse affect(s) on algae at low concentrations.
This could have serious consequences to nontarget algae species.
Therefore, at this toxicity level, additional higher-tiered testing is
required to further characterize the potential adverse affects to
aquatic plants. EPA is retaining the toxicity trigger of <1 ppm in test
note 5 to the final nontarget plant protection table in Sec.  158.2250.
    In evaluating test note 2 to the proposed nontarget plant
protection table in Sec.  158.2250, EPA has considered the commenter's
suggested table for nontarget plants. For the seedling emergence study,
the commenter used ``CR'' for most use patterns and suggested that the
seedling emergence study should only be required ``when environmental
exposure is likely to result under normal usage conditions as
determined by appropriate assessment methods.'' Another comment (see
response to comment 140.27 in the Response to Comments Document in the
docket) advocated for the use of a Risk Quotient (RQ) approach for
assessing plants.
    Based on this evaluation, EPA believes using ``CR'' for the
seedling

emergence study when triggered by a level of concern approach (RQ
approach) would provide EPA with the required data when needed. Test
note 2 to the final nontarget plant protection table in Sec.  158.2250
now reads as: Data are required if the risk quotient from any aquatic
plant growth Tier II study exceeds a level of concern for aquatic
plants.
    However, test note 2 also triggers the aquatic plant growth
(aquatic vascular plant) study, and is still the appropriate trigger
for that study. With this final rule, EPA is adding a new test note 10
to the final nontarget plant protection table in Sec.  158.2250, which
will read the same as the original, proposed test note 2 to the
proposed nontarget plant protection table in proposed Sec.  158.2250.

B. Alternative Format for Plant Protection Data Requirements Table

    1. Comment. In the comments submitted to EPA, the commenters
suggested an alternate antimicrobial plant protection data requirements
table.
    2. EPA's response. The table suggested by the commenter is not
adequate to evaluate the hazards and risks to nontarget plants from
antimicrobial pesticides. The suggested table did not include test
guideline numbers, changed and reduced the number of use patterns, and
proposed that all ecotoxicity plant studies are either not required or
only conditionally required. The commenter contends that there are no
circumstances where ecological effects plant data are relevant for
antimicrobial pesticides, and that indoor uses should not be subject to
environmental exposure or nontarget plant species risk assessments. EPA
disagrees with many aspects of these comments and the suggested
ecotoxicity data requirements table for plant species.
    As previously discussed, in the preamble to the proposed rule (73
FR 59406-7) and in Units III. and V. of this rule, EPA disagrees that
exposure for nontarget plants should be presumed to be minimal or
nonexistent for antimicrobials applied indoors, or that tests are not
required if the test organism is the target species for the pesticide
(see ACC comment, identified in the docket by document ID No. EPA-HQ-
OPP-2008-0110-0088.7, p. 12, test notes 1 and 2 to the commenter's
suggested table). Moreover, there are many outdoor uses of
antimicrobials that are not addressed in the commenter's suggested
table. FIFRA mandates that EPA conduct a risk assessment for any uses
for which exposure may occur in the various environmental compartments/
media. Those risks are assessed separately for the various taxa,
including plants, categories (e.g., freshwater, saltwater), and short-
term (i.e., acute) and longer-term (i.e., chronic) exposures. Assessing
these potential risks necessitates having an appropriate ecotoxicity
data base for plant exposure and toxicity. This can only be
accomplished by requiring plant studies for the initial assessment. A
tiered approach cannot be driven solely by risk quotients derived from
a Tier I study. The fact that an acute risk quotient for a plant
species does not exceed a level of concern for acute risk does not
imply that a chronic risk does not exist or that data are not needed to
assess that risk. The trigger for a chronic test is more likely driven
by the frequency, duration, or magnitude of the chronic exposure and
the environmental properties of the pesticide. For example, plants
might be subjected to repeated low-level exposure that is not acutely
lethal but which may impact reproductive success and plant growth.
    EPA disagrees that the test substance for plant studies (in the
commenter's table) should be identified simply as the ``residue of
concern (ROC).'' In its proposed nontarget plant data requirements
table, EPA specified the test material (TGAI, TEP) to be used for each
study. The test substance determination is made after reviewing the
required environmental fate and physical/chemical properties data and
any other available information (e.g., open literature, closely related
chemicals) to determine the substance of concern for exposure of non-
target plants and organisms. For example, if an applicant can
adequately demonstrate that the TGAI dissipates so rapidly that there
would be no acute or chronic exposure, TGAI testing may be waived, and
instead degradate testing may be required.
    The commenter also omitted all guideline numbers from its suggested
data table. At this time, all data requirement tables in 40 CFR part
158 have guideline numbers since this is a method of providing
information to applicants. Applicants are not required to use these
guidelines, but are encouraged to use these test guidelines when
developing data. Since these guidelines have been developed via a
rigorous process, as discussed in the preamble to the proposed rule [73
FR 59387], ``they represent the recommended approach to developing
high-quality data that should satisfy EPA's data needs for risk
assessment.''

XIII. Applicator and Post-Application Exposure Data Requirements

    The following represent the significant comments received on the
need for and evaluation of applicator and post-application exposure
studies as proposed by EPA. Changes from the proposed rule to the final
rule are also described. A more detailed discussion can be found in the
Response to Comments Document available in the docket to this rule.

A. Consistency With OSHA and Other Standards

    1. Comment. A commenter asserted that EPA should be consistent with
OSHA and other standards with regard to exposure limits and handling
practices, and incorporate the OSHA standards into risk assessment
evaluations. The commenter also asked that when EPA believes that an
OSHA or American Conference of Governmental and Industrial Hygienists
(ACGIH) standard is not adequately protective for an antimicrobial,
that the finding should be substantiated.
    2. EPA's response. The OSHA workplace standard is the permissible
exposure limit (PEL). When developing a PEL, OSHA considers the
toxicity of the chemical, often using data from the open literature as
well as the feasibility that exposures could be reduced to the PEL
using process modifications, engineering controls and personal
protective equipment (PPE). Approximately 500 PELs have been
established.
    The ACGIH establishes health-based Threshold Limit Values (TLVs),
which are non-governmental guidelines used by professional industrial
hygienists in making decisions about safe levels of exposure to a
chemical substance in the workplace. The TLVs were established for some
chemicals as early as 1946 and they are updated on a regular basis as
new health effects information becomes available. Like the OSHA PELs,
the TLVs are based on health effects data from the open literature.
However, unlike the OSHA PELs, feasibility issues are not considered in
establishing TLVs. TLVs are not available for most pesticide chemicals.
    However, for those pesticide chemicals with both TLVs and RfCs
(Reference Concentrations are established by OPP based on studies
submitted by the registrants), the RfCs are often lower than the TLVs.
There could be several reasons for such differences. The data used by
OPP is submitted by the pesticide registrants and the toxicity data
base is composed of animal studies. So, uncertainty

factors are used to derive the RfCs (exposure limits). Instead of
animal studies, ACGIH prefers to rely on epidemiology studies/case
reports of human, particularly worker, exposures from the literature
and on professional judgment.
    For example, ACGIH and OPP established different inhalation limits
for formaldehyde based on slightly different interpretations of the
same literature studies. The TLV for formaldehyde is 300 ppb and the
OPP ``RfC'' for occupational uses is 100 ppb. Although the TLV is
greater than the ``RfC,'' ACGIH does acknowledge in their TLV
documentation that irritation can occur in some workers at levels of
100 to 300 ppb.
    EPA believes that an existing OSHA or ACGIH standard should be
considered as part of EPA's hazard evaluation. However, before using an
OSHA or ACGIH standard, EPA would review the standard and the health
effects (toxicology) documents supporting the standard's development to
determine if EPA believes that the standard provides adequate
protection. EPA agrees with the commenter that EPA's evaluation of an
existing OSHA or ACGIH standard should be part of its hazard evaluation
documentation.
    In its proposed rule, EPA proposed in the applicator exposure table
(40 CFR 158.2260(a)(1)) and the post-application exposure table (40 CFR
158.2270(a)(1)) to use established workplace standards, such as OSHA's.
The proposed language was:

If EPA determines that industrial standards, such as the workplace
standards set by the Occupational Safety and Health Administration,
provide adequate protection for a particular pesticide or a
particular use pattern, applicator exposure data may not be required
for that pesticide or the use pattern. Applicants should consult
with the Agency on appropriate testing before the initiation of
studies.

    In addressing this comment, EPA realized that this proposed
language is misplaced and also needs some textual modification. As
discussed previously, an OSHA PEL or ACGIH TLV standard is part of
hazard evaluation. If the PEL or TLV is determined to be adequate to
fulfill EPA's selection of a toxicity endpoint, then the types and
number of toxicity studies that may be required is impacted, not the
need for exposure data. Therefore, EPA has removed the language
originally proposed for Sec.  158.2260(a)(1) and Sec.  158.2270(a)(1)
concerning use of OSHA standards. With modifications, the language
appears in the final toxicity rule in Sec.  158.2230(e).

B. Poisoning Incident Data

    1. Comment. ``Poisoning incident data'' should not be incorporated
into this regulation unless the EPA can provide criteria to trigger the
need for exposure data based on poisoning incidents. Regulating based
upon anecdotal reports of ``poisoning'' is not appropriate.
    2. EPA's response. Both proposed Sec.  158.2260(b) and Sec.
158.2270(b) contained the following trigger for requiring exposure
data: ``Scientifically sound epidemiological or poisoning incident data
indicate that adverse health effects may have resulted from handling of
the pesticide.'' EPA understands that anecdotal reports may or may not
indicate a cause-effect relationship, i.e., that adverse health effects
may or may not have resulted from exposure to the pesticide. EPA agrees
that anecdotal reports may not substantiate a clear dose response
relationship of ``poisoning,'' and therefore, when not substantiated,
are not appropriate for regulatory endpoints. In-depth information on
the dose response is the critical information needed for regulatory
endpoints, and poisoning incident data rarely include this information.
However, EPA's intention was to use scientifically credible information
as a trigger for requiring exposure data. Based on this comment, EPA
has revised the toxicity triggers in Sec.  158.2260 and Sec.  158.2270
to clarify that poisoning incident data must have a clear cause-effect
relationship to indicate that adverse health effects have resulted from
exposure to the pesticide.

C. Use of Existing Post-Application Exposure Data

    1. Comment. A commenter argued that there is a significant amount
of post-application exposure data available that should be considered/
used before requiring data under FIFRA.
    2. EPA's response. EPA acknowledges that there are existing
exposure data either in the literature, or via other governmental
organizations such as OSHA, or academia, etc. When available and
appropriate, EPA uses such exposure data and/or information in its risk
assessments. For example, the risk assessments for both chlorine
dioxide and ethylene oxide relied heavily on the workplace air
concentration monitoring data available in OSHA's Chemical Exposure
Health Database (CEHD), formerly known as, Integrated Management
Information System (IMIS). To access CEHD, users navigate on the OSHA
homepage (http://osha.gov/) to Chemical Exposure Health Data under the
Data and Statistics section towards the bottom right of the page. Users
can search CEHD by Establishment Name, State, Zip Code, Year Range,
Standard Industrial Classification (SIC), North American Industrial
Classification System Code (NAICS), Chemical Abstracts Service Number
(CAS), Chemical Name, or Result Range.
    Applicants who are aware of existing data that could fulfill a data
requirement should submit the data to EPA. EPA will consider the
appropriateness and robustness of the data, and, if appropriate, will
use the data in the Agency's risk assessment.

D. Soil Residue and Indoor Surface Residue Dissipation Studies

    1. Comment. A commenter claimed that there is little justification
for requiring the soil residue dissipation and indoor surface residue
dissipation studies.
    2. EPA's response. In the proposed rule, EPA conditionally required
the soil residue dissipation study for both occupational and
residential scenarios. EPA agrees that the likelihood of requiring soil
residue dissipation data is low for the majority of antimicrobial use
patterns. The low likelihood is reflected in the ``CR'' designation in
the proposed post-application exposure data requirements table for the
soil residue dissipation study for both occupational and residential
use patterns. No changes are needed.
    In the proposed rule, EPA required the indoor surface residue
dissipation study for both occupational and residential scenarios.
However, the likelihood of requiring indoor surface residue dissipation
data is high for residential products such as antimicrobial-treated
clothing and plastic consumer items/toys, as well as direct
applications such as carpet shampoos, laundry detergents, and floor
cleaners that are antimicrobial products. Therefore, the indoor surface
residue dissipation study for the residential use sites will remain
``R'' as proposed.
    However, EPA has reevaluated the ``R'' proposed for occupational
use sites. When compared to residential use sites, occupational use
sites are less likely to result in the need for indoor surface residue
dissipation data. Therefore, the data requirement for indoor surface
residue data has been revised from ``R'' to ``CR'' for occupational
uses.
    In most manufacturing settings, there is less contact with surfaces
than in most residential scenarios. For example, under most
circumstances workers do not crawl around the floors of manufacturing
plants. The need for indoor surface residue dissipation data

for workers is limited by the residue distribution where contact may
occur. EPA now agrees that the occupational use sites are less likely
to result in the need for indoor surface residue dissipation data, and
therefore, the ``R'' has been revised to ``CR.''

E. Non-Dietary Ingestion Study

    1. Comment. A commenter asserted that the proposed requirement for
non-dietary ingestion is impractical and unnecessary, and, in fact,
could be replaced by modeling.
    2. EPA's response. EPA agrees that the non-dietary ingestion study
is impractical, as a stand-alone direct measurement study. Non-dietary
ingestion exposure (i.e., incidental oral ingestion by children) is of
potential concern for treated articles or surfaces that may be accessed
by children. For example, uses such as carpet shampoo, hardwood floor
treatments, pressure-treated wood, and impregnated materials (including
but not limited to plastic toys or treated clothing) are assessed for
non-dietary exposures when toxicity criteria are triggered. In all of
these instances, non-dietary ingestion exposures are estimated using
residue data from the treated surface combined with activity factors
for children's behaviors (e.g., frequency of hand-to-mouth contact).
Often, EPA models this route and pathway of exposure using inputs from
the available and reliable published research. If EPA were to require
data to estimate this exposure pathway, EPA would require surface
residue data, rather than the actual monitoring of children or having
individual registrants collecting data on frequency of hand-to-mouth
activities, as these are not chemical-specific. Given the unlikelihood
of requiring non-dietary ingestion exposure studies, EPA has determined
to not finalize this proposed data requirement and its accompanying
test note 12 in the final post-application exposure table in Sec.
158.2270(e).

XIV. Environmental Fate Data Requirements

    The following represent the significant comments received on the
need for and evaluation of environmental fate studies as proposed by
EPA. Changes from the proposed rule to the final rule are also
described. A more detailed discussion can be found in the Response to
Comments Document available in the docket to this rule.

A. Need for Environmental Fate Data for Indoor Uses

    1. Comment. Several commenters argued that the proposed
environmental fate data requirements for indoor uses of antimicrobials
should not exceed those in part 158 for conventional pesticide
chemicals, since antimicrobials are not directly broadcast into the
environment.
    2. EPA's response. As explained in the proposed rule, there is now
a greater concern regarding indoor uses of antimicrobials because those
antimicrobial uses can lead to environmental exposure when they go down
the drain. The rationale for requiring environmental fate data for
antimicrobials mirrors that of Unit XI.A. for requiring nontarget
organism data for antimicrobials.
    There are many uses for which a high potential for exposure exists,
and these uses may require a more extensive environmental fate data set
that could also include aerobic and anaerobic metabolism studies.
However, such uses will typically require a much reduced first tier
data set with additional testing triggered if the results of the
required data indicate a potential risk that needs further
characterization.

B. Transformation Products

    1. Comment. A commenter argued that the Agency has not clearly
stated when environmental fate data on the transformation products
would be required. Additionally, the commenter also wanted to
understand the data that would be required if the substance degrades
quickly?
    2. EPA's response. For environmental fate data, the Agency
evaluates transformation products on a case-by-case basis, using
several sources of information. First, the transformation products need
to be identified. While product chemistry data can provide some
information on degradates, environmental fate data provide data
specific to a particular environmental compartment. Environmental fate
studies provide information on the stability and persistence of the
active ingredient and its degradation products in the various
environmental media. For example, in the hydrolysis study, a half-life
>30 days indicates that the substance is stable to hydrolytic
processes, i.e., the substance did not degrade. Similar determinations
are made based on the results of the photodegradation in soil and water
studies, and the aerobic and anaerobic metabolism in soil and water
studies after review of the required fate data. Monitoring and incident
data, if available, also may indicate stability and persistence. There
could also be environmental fate data conducted on a related chemical
or information from the open literature. This analysis is critical to
determining not only the need for environmental fate data for
transformation products, but also is the first step for determining the
need for nontarget organism or nontarget plant data for transformation
products.
    EPA proposed criteria to require testing of transformation/
degradation products or leachate residues in proposed Sec.
158.2280(a)(2) and (3). To respond to this comment, EPA also considered
a similar comment on transformation/degradation products or leachate
residues for nontarget plant and organism testing (see Unit XI.B.). In
response to these comments, EPA determined to clarify and revise the
criteria for testing of transformation/degradation products and
leachate residues for nontarget organisms in Sec.  158.2240(a)(3), for
environmental fate in Sec.  158.2280(a)(2), and for nontarget plant
protection in Sec.  158.2250(b).
    EPA would use these criteria to determine if environmental fate
data on the transformation/degradation products or leachate residues
are required. Therefore, if the environmental fate studies on the
parent indicate the transformation product(s) is, for example, more
persistent in soils, then the same environmental fate data required for
the parent are required for the transformation product(s). If concerns
are identified, then higher-tiered environmental fate and/or ecological
effects data on the transformation/degradation product(s) would be
required.
    It should be noted that the criteria for determining whether to
assess risks from a chemical substance and/or its degradation products
when conducting a down-the-drain analysis are different from those
discussed previously. Those criteria are discussed in response to
comment 130.4 in the Response to Comments Document in the docket.

C. Photodegradation in Soil Study

    1. Comment. A commenter claimed that EPA has not sufficiently
explained why a photodegradation in soil study would be required if a
substance hydrolyzes and its behavior is known from its soil profile.
    2. EPA's response. EPA proposed to require the photodegradation in
soil study for only one use pattern: Wood preservatives. Wood products
that have been treated with wood preservatives are often in contact
with soil, and therefore it is possible for the wood preservative
chemical, as well as its transformation and degradation products, to
leach out from the treated wood product. To understand the fate of wood
preservative chemicals in soil, first requires an understanding of the
soils properties. Soil profiles are

descriptions of soil properties, both physical and chemical. Examples
of physical characteristics would include: color, bulk density, and
texture. Examples of chemical characteristics would include: pH of the
soil, organic matter content, and Cation Exchange Capacity (CEC).
Depending on the soil profile, an antimicrobial pesticide can undergo
chemical and/or biochemical (biodegradation) processes. For example, if
the pH of the soil is less than 7, the antimicrobial can undergo
hydrolysis and become nonpersistent, or if the pH of the soil is basic,
the antimicrobial could remain stable and become persistent. If the
organic carbon content of a soil is high, then the soil has a high
microbial population which facilitates the biodegradation process.
Hence the nature of a soil (soil profile) is an important indicator of
how a pesticide may behave in a soil.
    Many applicants are well aware of soil profiles, since EPA asks for
the soil profile to be submitted along with the results of the studies
in soils. A number of soil profile data bases are available. Two of the
data bases used by OPP are one from the United States Department of
Agriculture (USDA) and one called CLARION.
    In this final rule, EPA has retained the requirement for a
photodegradation in soil study for the wood preservatives use pattern.
The photodegradation in soil study is required for all wood
preservatives, except for two circumstances. First, if the
antimicrobial is an inorganic substance or a metal salt, then a
photodegradation study does not provide applicable information for
inorganics and metal salts that do not degrade (chemically or
biochemically). Second, if data from standardized soil profiles show
that the chemical is likely to readily degrade microbially or undergo
redox reactions (degrade chemically) to such a degree that there is no
formation of degradation/transformation/leachate products of concern
(as defined in Sec.  158.2280(a)(2)), then the photodegradation in
soils study would not be needed. EPA has revised the proposed test note
10 to the environmental fate table, so that test note 10 to the final
environmental fate table in Sec.  158.2280(c) explains the conditions
for not requiring the photodegradation in soil study.

D. Aquatic Sediment Study

    1. Comment. A commenter claimed that EPA is unclear about the
triggers that would lead to the requirement for an aquatic sediment
study, and how down-the-drain modeling could affect the need for this
study.
    2. EPA's response. Test notes 5 and 13 to the proposed
environmental fate table in Sec.  158.2280 trigger the aquatic sediment
study for all use patterns except the aquatic areas use pattern. EPA
has reevaluated the need for the aquatic sediment study and the
appropriate triggers. EPA agrees that having two triggers, both of
which use a weight-of-evidence evaluation process, is confusing, and
believes that one trigger (proposed test note 13) would be sufficient
for triggering the aquatic sediment study. In this final rule, EPA is
removing test note 5 from the test note column for the aquatic sediment
study data requirement. Based on this reevaluation, EPA also believes
that the aquatic sediment study should be required for the antifoulant
coatings and paints use pattern since an antifoulant use would meet the
criteria of the trigger in test note 13, which is: ``* * * data are
required based on the potential for aquatic exposure and if the weight-
of-evidence indicates that the active ingredient or principal
transformation products are likely to have the potential for
persistence, mobility, nontarget aquatic toxicity, or
bioaccumulation.'' Antifoulants are released/applied directly to the
aquatic environment. These products are often manufactured to be
persistent, and because of the continuous release process, some of the
active ingredient is likely to be transferred to the bottom of the
water column and then be adsorbed to the sediment. This is likely to
result in adverse effects on nontarget benthic organisms. Since this
meets the triggers for requiring the study, in this final rule EPA is
changing the ``CR'' for the aquatic sediment study for the antifoulant
coatings and paints use pattern to ``R.''
    The aquatic sediment study provides information about the
degradation/dissipation processes under field conditions. The results
of down-the-drain modeling are unlikely to provide appropriate
information to determine the need for the aquatic sediment study. The
current version of the down-the-drain model estimates concentrations of
chemical substances in the water column downstream of wastewater
treatment facilities, but does not estimate concentrations in the
sediment.

E. Monitoring of Representative U.S. Waters Study

    1. Comment. The commenter noted that there is no guidance on how to
conduct a ``monitoring of representative U.S. waters'' study, and that
EPA has not provided the criteria for triggering a ``monitoring of
representative U.S. waters'' study.
    2. EPA's response. The commenter is correct. EPA does not have a
guideline for conducting this study. For all pesticides, such
monitoring (studies) of representative U.S. waters is a very rare
occurrence. If EPA were to require such a monitoring study, protocols
would have to be developed to specify a great deal of information:
     At which locations would the monitoring occur, and how
often would the monitoring occur?
     Is the sampling for ground water, surface water, or the
estuarine/marine environment?
     Which chemical substances would be monitored? Is just the
antimicrobial (parent) to be analyzed, or would the transformation/
degradation products also be analyzed?
    Such a protocol would be specific to a particular pesticide, where
that pesticide is used, and where the pesticide has been detected, and
could not necessarily be used for a different pesticide.
    For the monitoring of representative U.S. waters data requirement,
the term ``residue of concern'' (ROC) is currently specified in the
environmental fate data requirements table in the test substance to
support column. Since the ROC would be determined during protocol
development, EPA is adding this information as part of a new test note
17 to the final environmental fate table in Sec.  158.2280.
    As stated in the preamble to the proposed rule, a WOE approach
would be used to determine if a monitoring of representative U.S.
waters study should be required. The preamble to the proposed rule
discusses this aspect in more detail (73 FR 59413). EPA expects this
study to be rarely required.

F. American Wood Protection Association (AWPA) and American Society for
Testing and Materials (ASTM) Methods

    1. Comment. A commenter argued that AWPA method E11-97 or E20-04,
and ASTM Method D5108-90 ``are of limited or no relevance to estimating
environmental exposures'' for wood preservatives, or antifoulants,
respectively. According to the commenter, the results of the ASTM
method are not suitable for ``estimating release rates for regulation
purposes.'' The commenter believes that both methods ``overestimate
leach rates and are not intended for use in risk assessments.'' The
commenter also provided information to indicate that ASTM Method D5108-
90 has been replaced by ASTM D6442-06.
    2. EPA's response. Test note 15 to the proposed environmental fate
table in

Sec.  158.2280 triggers the special leaching data requirement for the
wood preservative use pattern. EPA's intent in specifying that it would
accept an ASTM or AWPA method was to allow applicants to use these
readily available protocols. However, as noted in the proposed test
note, protocol review was still required for some of these methods.
Since the commenters believe that these AWPA methods are inappropriate,
but have not offered alternative methods, test note 15 to the final
environmental fate table in Sec.  158.2280(c) is revised to remove the
AWPA methods. Test note 12 to the final environmental fate table in
Sec.  158.2280(c) is added to require protocol review.
    Test note 16 to the proposed environmental fate table in Sec.
158.2280 triggers the special leaching data requirement for the
antifoulant coatings and paints. Since the commenter indicated that the
ASTM method has been replaced, EPA believes that specifying an ASTM
method number in regulatory text may provide insufficient clarity, at
some point in the future. Therefore, test note 16 to the final
environmental fate table in Sec.  158.2280 is revised to remove the
ASTM methods. Test note 12 to the final environmental fate table in
Sec.  158.2280(c) is added to require protocol review.

XV. Down-the-Drain Analysis

    The following represent the significant comments received on the
need for and performance of a down-the-drain analysis as proposed by
EPA. Changes from the proposed rule to the final rule are also
described. A more detailed discussion can be found in the Response to
Comments Document available in the docket to this rule.

A. Changes to Down-the-Drain Analysis Based on Comments Received

    1. Comment. Some commenters expressed concern regarding EPA's
proposal to exclude antifoulants and wood preservatives from testing
designed to protect POTWs and the aquatic environment. These commenters
contend that these compounds may reach POTWs through sources such as
hull blast water, landfill leachate, and centralized waste treatment
facilities. They think EPA should revisit this assumption to verify its
accuracy.
    2. EPA's response. Based on this comment, EPA did reevaluate its
original determination to exclude antifoulant coating and paints, wood
preservatives, and aquatic areas from down-the-drain analysis. EPA
still believes that it is appropriate to exclude aquatic areas from a
down-the-drain analysis. As discussed in the preamble to the proposed
rule (73 FR 59390) aquatic areas include lakes, ponds, streams,
drainage ditches, and other bodies of water. These would not be
expected to result in down-the-drain releases and are therefore
unlikely to be discharged to a WWTP.
    Based on its reevaluation, EPA believes that a down-the-drain
analysis is needed for the wood preservative, and antifoulant paints
and coatings use patterns, as well as the all other use patterns
category. There are a number of sources of indirect releases of
antifoulants and wood preservatives to surface water via WWTPs. The
Emission Scenario Document (ESD) for Wood Preservatives, which is part
of the OECD Series on Emission Scenario Documents, documents numerous
sources of environmental releases directly to surface water. The ESD
also describes various types of wood preservative facilities where
there may be environmental releases to the facility drain that
subsequently drains to a WWTP. Some of the types of wood preservative
facilities identified in the OECD ESD for wood preservatives include
automated spraying plants, dipping/immersion plants, and plants that
employ vacuum-pressure and double vacuum processes. According to this
OECD ESD for wood preservatives, it is also possible for releases to
sewage treatment plants to occur from some treated wood products, such
as noise barriers.
    According to the OECD ESD for Antifouling Products, in addition to
the numerous sources of direct environmental releases to surface water
resulting from the use of antifoulant paints and coatings, there is the
potential for antifoulants to enter sewage treatment plants as a result
of application and removal of antifoulant paints at boatyards and
marinas.
    Thus, OPP's Antimicrobial Division (AD) will perform a down-the-
drain assessment for every product with an applicable use or exposure
scenario that has the potential for waters containing antimicrobials to
reach a WWTP. To perform this assessment, the Agency is requiring data
on the biodegradation of an antimicrobial pesticide and its potential
toxicity to WWTP microorganisms in an activated sludge basin. For some
antimicrobial pesticides, the Agency will also require the activated
sludge sorption isotherm test to determine removal from wastewater via
partitioning to activated sludge. For additional information on the
changes made to the proposed environmental fate data requirements table
see response to comment 134.1 in the Response to Comments Document in
the docket.

B. Use of E-FAST Model

    1. Comment. According to one commenter, EPA staff indicated at the
part 158, subpart W Antimicrobials Data Requirements Workshop held on
November 6, 2008 that the E-FAST model may have been based on municipal
WWTPs that received only ``residential'' discharges. The commenter
suggested that is very unlikely and stated that according to the E-FAST
manual, the model was based on data from actual U.S. municipal WWTPs.
Nearly every municipal WWTP receives discharges from many types of non-
residential sources, like commercial facilities, medical facilities,
institutions, and cooling water systems (which are common in commercial
buildings). Even in smaller communities, POTWs receive wastewater from
residential and commercial (e.g., schools, stores, restaurants, hotels/
motels, and/or medical facilities) sources. Most municipal WWTPs also
receive both process and non-process discharges from industrial
facilities. Some commenters contend that the E-FAST model is applicable
as a screening-level model for all antimicrobial use patterns with
discharges that are typically rinsed down the drain including
agricultural premises and equipment, food handling/storage
establishments, residential and public access premises, medical
premises and equipment, industrial processes and water systems,
swimming pools, and others.
    2. EPA's response. The E-FAST documentation manual indicates that
the down-the-drain module was developed as a screening-level model for
estimating concentrations of chemicals in surface water that may result
from the disposal of consumer products into household wastewater. The
model developers have confirmed, however, that the data base of WWTPs
that is accessed by this module consists of domestic WWTPs that receive
wastewaters predominantly from residential, commercial, and
institutional sources, and not solely from residential sources. In
modeling releases of antimicrobial pesticides to environmental media,
the appropriate data inputs, methods, and tools are dependent upon the
source of the environmental releases. To assess exposures and risks to
releases of antimicrobial pesticides to surface water from residential,
commercial, and institutional sources, the down-the-drain module of E-
FAST is the most appropriate tool.

    To assess exposures and risks to antimicrobial pesticides from
manufacturing, processing, and industrial use facilities, the general
population and ecological exposures from the industrial releases module
of E-FAST is the most appropriate tool. The decision to use the general
population and ecological exposures from the industrial releases module
is made on a case-by-case basis considering the availability of data
required as inputs to the module, and the potential for significant
exposure. For example, a low volume use may not require use of this
module.
    EPA agrees that the E-FAST model is applicable as a screening-level
model for all antimicrobial use patterns with discharges that are
typically rinsed down the drain, including agricultural premises and
equipment, food handling/storage establishments, residential and public
access premises, medical premises and equipment, industrial processes
and water systems, swimming pools, and others.

C. Exceedance Levels

    1. Comment. Some commenters questioned the justification for the
following exceedance levels that were used by EPA to evaluate potential
risks to aquatic organisms:
    i. Potential risks from effects to aquatic invertebrates and fish:
Exceedance of the chronic concentration of concern (COC) for 20 or more
days triggers a potential for concern;
    ii. Potential risks from effects to aquatic invertebrates and fish:
Exceedance of the acute COC for 4 or more days triggers a potential for
concern; and
    iii. Potential risks from effects to algae: Exceedance of the COC
for algae for 4 days or less may trigger a concern and is evaluated on
a case-by-case basis.
    2. EPA's response. Exceedance levels and corresponding number of
days of exceedance that trigger potential for concern are those cited
in EPA/OPPTS/OPPT's ``Interpretive Assistance for Sustainable Futures
Summary Assessment'', last updated August, 2011. The justification that
the potential for chronic risk to aquatic organisms may exist if the
predicted environmental concentration (PEC) exceeds the chronic COC and
the exceedance occurs for 20 days or more per year is documented on
page 11:

    The potential for chronic risk to aquatic organisms may exist
ONLY if the PEC exceeds the chronic COC for 20 days or more per
year. If exposure occurs for 20 days of more per year, the
concentration of the chemical in surface water may reach levels
associated with chronic effects (Lynch et al., 1994). The 20-day
criterion is derived from partial life-cycle tests (Daphnid chronic
and fish early life-stage tests) that typically range from 21 to 29
days in duration. Low concentration for chronic risk exists if the
COC is exceeded on fewer than 20 days per year.

    The justification for the potential for acute risks to aquatic
organisms appears on page 12:

    The potential for acute risk to aquatic organisms exists if the
predicted environmental concentration (PEC) is greater than the
acute concentration of concern (COC).
    If Acute COC > PEC: Low concern for risk
    If Acute COC < PEC: Potential for risk

    EPA notes that risk is influenced by both the duration of exposure
and the likelihood of that exposure occurring. Often mathematical
models are used to estimate exposures and risks. There are two types of
models: Deterministic or probabilistic. Probabilistic modeling is a
technique that utilizes the entire range of input data to develop a
probability distribution of risk or exposure rather than a single point
value. The analysis identifies the probability that the exposure
exceeds the COC and for what timeframe. Deterministic modeling is based
on select input data that result in a single point estimate. The
estimate either exceeds or does not exceed the COC. Models such as E-
FAST have the capability of providing either deterministic or
probabilistic results. Consequently, criteria for determining whether
or not testing on aquatic organisms is required need to take into
account the possibility that the estimated exposure could be modeled
using either deterministic or probabilistic modeling. Therefore, two
test notes to the final nontarget organism table in Sec.  158.2240 have
been revised to include a probabilistic trigger for down-the-drain
analyses, while retaining the existing deterministic trigger for
releases of antimicrobials that are expected to enter WWTPs. Test note
7 to the final nontarget organism table in Sec.  158.2240(c) triggers
the acute freshwater invertebrate toxicity study (TEP testing) and the
acute freshwater fish toxicity study (TEP testing). Test note 12 to the
final nontarget organism table in Sec.  158.2240(c) triggers the fish
life-cycle study.

D. Evaluation of Discharges to Still Water and to Salt Water

    1. Comment. During the Antimicrobial Data Requirements Workshop
held on November 6, 2008, EPA staff indicated that evaluation of
discharges to still water and to salt water would be challenging. The
commenter argued that the E-FAST model manual suggests that these
discharges can be readily evaluated with appropriate input data and
elimination of the PDM (Probabilistic Dilution Model) option.
    2. EPA's response. EPA believes that the commenter misunderstood
the context of the Information provided by EPA staff both in the
proposed rule and at the presentation on November 6, 2008. E-FAST has
two modules for estimating releases to surface water: The down-the-
drain module, and the general population and ecological exposure from
industrial releases module.
    When the down-the-drain module of E-FAST is run without the PDM
option, the results are limited to estimates of concentrations in
surface water downstream of domestic wastewater treatment facilities.
The down-the-drain module has no option for estimating concentrations
in non-flowing waterbodies such as lakes, bays, estuaries, and oceans.
The discussion at the November 6, 2008, Workshop focused solely on the
down-the-drain module.
    E-FAST, however, has the capability for evaluating discharges to
still water and to salt water from discharges to WWTPs that receive
manufacturing, processing, and industrial use releases, but not from
discharges to surface water via domestic WWTPs. The general population
and ecological exposure from industrial releases module is designed to
estimate releases to air, water, and land from manufacturing,
processing, and industrial use of chemical substances. The data base
for estimating releases to WWTPs that primarily receive wastewater from
manufacturing, processing, and industrial uses requires estimates of
releases to environmental media from models such as ChemSTEER (Chemical
Screening Tool for Exposures and Environmental Releases), a model
developed by EPA's OPPT or from data and calculations included in
standard scenarios, also developed by OPPT (www.epa.gov/oppt/exposure/pubs/chemsteerdl.htm). The general population and ecological exposure
from industrial releases module includes an option for estimating
concentrations in lakes, bays, estuaries, and oceans.

E. Parameters for Down-the-Drain Analysis

    1. Comment. Several commenter's argued that EPA's approach for
down-the-drain chemicals separates the exposure and the effects of the
assessment and subjects chemicals to similar testing requirements
regardless of the mass of chemicals disposed of in

the environment. According to these commenters, the fact that EPA does
not guide testing by the extent of environmental exposure is wasteful
for ingredients which will reach the environment at low levels. Even
for chemicals which are used at greater volume, the commenters claimed
that there is no proof that EPA's program will achieve its goal without
being wasteful and some commenters believe that EPA's approach will
likely result in significant unwarranted costs in animals, time, and
dollars. The commenters asserted that this will result in unnecessary
loss of animals, increased costs to the consumer and will negatively
affect product innovation as new product development will be slowed due
to the extra regulatory burden. The benefit to the environment of the
EPA approach, according to the commenters, is likely to be small and
not commensurate with its costs.
    2. EPA's response. EPA disagrees with this comment. Three key input
parameters for the down-the-drain model are:
    i. Percent removal of antimicrobial pesticide during wastewater
treatment;
    ii. Concentrations of concern for antimicrobial pesticides based on
acute and chronic end-points for freshwater fish, freshwater
invertebrates, and freshwater plants; and
    iii. Wastewater treatment plant influent volume of antimicrobial
pesticide.
    As demonstrated in the sensitivity analysis of the down-the-drain
model in the document, ``Four Case Studies of Antimicrobial Pesticides
in the Down-the-Drain Screening Model, Using the Proposed Approach for
a Screening-Level Environmental Fate Assessment'' (identified in the
docket by document ID number EPA-HQ-OPP-2008-0110-0044), the amount of
chemical disposed in the environment strongly influences the results of
the down-the-drain model. It is possible that if the amount of chemical
disposed is small (i.e., WWTP influent volume is low and/or high
percent removal during wastewater treatment), the predicted surface
water concentration of the antimicrobial, even for a chemical of high
toxicity, would not exceed the Agency's level of concern. Under such
circumstances, higher-tier testing (environmental fate, ecotoxicity,
and plant protection) is unlikely to be triggered. Since higher-tier
testing is triggered only if the down-the-drain model indicates that
the predicted concentration of the antimicrobial may adversely affect
aquatic organisms this reduces the number of tests required, and
therefore the animals, time, and dollars.
    EPA also notes that two of the three key input parameters needed to
run the down-the-drain model, percent removal during wastewater
treatment and wastewater treatment plant influent volume do not involve
animal testing and would not lead to loss of animals. Fate tests
required to determine removal during wastewater treatment via
biodegradation and adsorption are inexpensive. No costs are associated
with WWTP influent volume.

F. Acute and Chronic Toxicity Endpoints

    1. Comment. At the Antimicrobial Data Requirements Workshop held on
November 6, 2008, EPA staff indicated that chronic aquatic toxicity
endpoints might not be used to evaluate antimicrobial discharges from
municipal WWTPs. A commenter argued that since EPA/OW requires
municipal WWTPs to conduct both acute and chronic toxicity tests
regularly as conditions of CWA-regulated National Pollution Discharge
Elimination System (NPDES) permits, both acute and chronic endpoints
should be evaluated by EPA/OPP to ensure that antimicrobial discharges
will not cause toxicity in municipal WWTP effluent.
    2. EPA's response. To assess whether the proposed screening level
assessment and tiered system of data requirements provides the data
needed to assess exposure and risk of antimicrobial pesticides released
to the environment via down-the-drain use patterns, the Agency
conducted four case studies (73 FR 59408-9). Based on this comment, EPA
has reevaluated the approach used for the case studies, in which the
higher-tiered data was triggered based on the results of the available
data. To ensure that antimicrobial discharges will not cause toxicity
to aquatic organisms downstream of WWTP effluents requires an
evaluation of both acute and chronic toxicity endpoints. This means
that the chronic ecotoxicity data needs to be submitted at the same
time as the acute ecotoxicity data, so both types of studies are
available for EPA to use for the ecological risk assessment. Also see
Units XV.A. and B.
    Consequently, in the final nontarget organism table in Sec.
158.2240(c), the table descriptors for the fish early-life stage and
aquatic invertebrate life-cycle tests have been changed from ``CR'' to
``R'' for the wood preservatives use pattern and the all other use
patterns category. Test note 10 to the final nontarget organism table
in Sec.  158.2240(c) has been modified to remove the trigger since it
is no longer needed.

XVI. Residue Chemistry Data Requirements

    The following represent the significant comments received on the
need for and evaluation of residue chemistry studies as proposed by
EPA. Changes from the proposed rule to the final rule are also
described. A more detailed discussion can be found in the Response to
Comments Document available in the docket to this rule.

A. Scope of the Residue Chemistry Data Requirements

    1. Comment. Several commenters found the scope of coverage of the
residue chemistry data requirements in Sec.  158.2290(b) to be vague
and confusing. Further, the ACC Biocides Panel asserted that this
section required data for uses for which a FFDCA section 408 tolerance
is not required and over which, therefore, EPA allegedly has no
jurisdiction.
    2. EPA's response. EPA is clarifying Sec.  158.2290(b) which
pertains to the scope of the residue chemistry data requirements. That
section can be read as limiting the residue chemistry data requirements
to pesticide products requiring a tolerance or tolerance exemption.
This apparent limitation is inconsistent with both the preamble's
general description of the scope of subpart W and the preamble's
description of the scope of the residue chemisty data requirements
section, and is internally inconsistent with the terms of Sec.
158.2290(b). Various commentators noted the lack of clarity in this
portion of the rule.
    The preamble's general discussion of the scope of subpart W made
clear that this subpart was not limited to ``antimicrobial pesticides''
as defined by FIFRA section 2(mm)--which excluded antimicrobial
pesticide uses subject to either FFDCA section 408 or section 409--but
extended to among other things, ``[p]esticide products for
antimicrobial use in/on food'' (73 FR 59385). In no way, however, did
this discussion suggest or imply that the subpart is limited to
antimicrobial uses requiring FFDCA section 408 tolerances or exemptions
from tolerances. To the contrary, the preamble's discussion of toxicity
data requirements expressly notes that data are needed under subpart W
to assess dietary risk whether or not a section 408 tolerance is
required. The preamble specifically states that, although certain
antimicrobial food uses are regulated under the FFDCA by FDA under
section 409 and not section 408, EPA still needs

data on these uses to assess dietary risk to fulfill its statutory
obligations under FIFRA section 2(bb)(2), which establishes the FFDCA
section 408 safety standard as a component of the FIFRA standard for
registration/cancellation for FIFRA pesticide uses that result in
residues on food (73 FR 59394). Further, the preamble's discussion of
residue chemistry data requirements states that these data are needed
for ``direct and indirect food uses'' including application to ``food
or water'' both to assess risk and for tolerance-setting purposes (73
FR 59401: ``In addition to dietary risk assessments, residue chemistry
data are used to establish pesticide tolerance. . . .''). Finally, both
the preamble's discussion of residue data requirements and the relevant
rule text mention antimicrobial uses that would be excluded by a
limitation of the rule to antimicrobial uses requiring tolerances. For
example, both the preamble and rule text refer to ``fruit and vegetable
rinses,'' antimicrobials ``incorporated into a material that may
contact food or feed,'' and ``[a]quatic uses that have the potential to
result in residues in potable water'' and the fact that all of these
uses may not need section 408 tolerances (73 FR 59401 and 59444).
    Accordingly, EPA is revising Sec.  158.2290(b) to make clear it is
not limited to antimicrobial uses which need FFDCA section 408
tolerances. With some modifications, EPA is retaining in Sec.
158.2290(b) a non-exclusive list identifying examples of antimicrobial
products covered by this section. The revision to the introductory text
of Sec.  158.2290(b)(1) makes clear that the residue data requirements
apply to antimicrobial products that may result in residues in food or
water whether or not a FFDCA section 408 tolerance is needed.
    The first item in the list of covered uses now reads ``Products
that require a tolerance, tolerance exemption, or food additive
regulation or clearance.'' The insertion of the reference to food
additive regulations and clearances is consistent with the rule's scope
which is not limited to pesticide uses regulated under FFDCA section
408. Additionally, each of the subparagraphs listing examples of
covered uses has been revised to refer to ``products'' rather than
``uses'' for consistency and clarity. Although the subparagraphs are
overlapping (i.e., a product may fall in more than one paragraph), the
revised subsection now clarifies the overall scope of the section.
These revisions make Sec.  158.2290(b) consistent with the scope of the
rule described in the preamble and the scope of the toxicology data
requirements.
    Not only are these changes consistent with the scope of the rule as
discussed in the preamble (i.e., data requirements are not limited to
uses needing section 408 tolerances) but the revised language's focus
on whether use of a pesticide may result in residues in or on food
follows directly from the intent of the residue chemistry requirements
as discussed in the preamble. There, EPA explained that the proposed
requirements will provide information ``to better estimate human
dietary exposure to antimicrobial residues in or on food or feed,''
``to determine the composition of the pesticide residue and how much of
the residue is present in food or animal feed,'' and to ``measure how
much of the residue of concern is present in food, feed, and water''
(73 FR 59401). Further, the revised language is consistent with the
scope of FFDCA section 408 (applies to ``pesticide chemical residue[s]
in or on food'') and FIFRA (requires consideration of ``residues that
result from the use of a pesticide in or on food''). It also follows
directly from the existing data requirements applying to antimicrobials
in part 161. Those regulations provide that ``Residue Chemistry Data
are used by the Agency to estimate the exposure of the general
population to pesticide residues in food and for setting and enforcing
tolerances for pesticide residues in food or feed.'' 40 CFR
161.202(c)(1); see also 40 CFR 161.202(c)(2) (``results of tests on the
amount of residues remaining on or in the treated food or feed are
needed to support a finding as to the magnitude and identity of
residues which result in food or animal feed as a consequence of a
proposed pesticide usage''); 40 CFR 161.240(b)(14) (Residue data on
indoor use of pesticide ``if such a use could result in residues in
food or feed''). Finally, the revised language also tracks EPA's
requirements for residue chemistry data under the current data
requirements for conventional pesticides in 40 CFR part 158, subpart O.
In the preamble to the proposed rule, EPA explained that the residue
data requirements for antimicrobials were adapted from the conventional
data requirements in subpart O (73 FR 59401). For uses of conventional
pesticides, other than uses in agriculture, part 158 states that
``[residue chemistry] [d]ata may be required . . . if residues may
occur in food or feed as a result of the use.'' (40 CFR
158.1410(b)(2)). The regulation also makes clear that this requirement
applies whether or not a tolerance is needed under FFDCA section 408.
The regulation specifies that ``most products used in or near kitchens
require residue data for risk assessment purposes even though
tolerances may not be necessary in all cases.'' (Id.)
    The commenters' concern that the residue chemistry requirements
exceeded EPA's jurisdiction under the FFDCA is addressed in Unit IV.

B. Complete Transference of the Antimicrobial into Food

    1. Comment. The commenter believes that additional clarification is
needed concerning EPA's statement, ``in the absence of data [the Agency
will] evaluate the need for a tolerance or tolerance exemption by
assuming complete transference of the chemical into food over the
lifetime of the treated product.''
    2. EPA's response. Complete transference refers to an assumption
that the Agency would initially make regarding the migration of
antimicrobial residues from an impregnated food contact material to the
food contacting that material over the typical use life of the
antimicrobial-impregnated material. The worst-case assumption is that
100 percent of the antimicrobial residues resulting from use at the
maximum registered rate transfers into the food, which is then used to
estimate a conservative dietary exposure. If the aggregate risk
calculated using this conservative assumption, from use of the
antimicrobial in question, is less than EPA's level of concern, then no
measured data are needed. If the aggregate risk meets or exceeds EPA's
level of concern, then chemical-specific data quantifying residue
migration to refine this dietary exposure component may be required. To
refine the exposure, the applicant may choose to perform one or more of
the FDA protocols to estimate migration rate into food stimulants (see
document ID number EPA-HQ-OPP-2008-0110-0013). Alternatively, or
subsequently, the applicant may choose to conduct a chemical-specific
nature of the residue on surfaces study and a migration study
investigating actual impregnated materials using representative foods.

C. Alternative Formats for Residue Chemistry Data Requirements Table

    1. Comment. Two different commenters suggested two different
options as alternative approaches to the antimicrobial residue
chemistry data requirement table proposed by EPA. One of the commenters
separated the residue chemistry data requirements into two tables,
referred to as Part 1 and 2 (ACC comment, identified in the

docket by document ID number EPA-HQ-OPP-2008-0110-0088.10, p. 7). The
other commenter suggested a single table format (CSPA Comment,
identified in the docket by document ID number EPA-HQ-OPP-2008-0110-
0086.2).
    2. EPA's response. All three of the commenter-suggested tables had
the same five ``Supporting Information'' studies as the first section
of the table proposed by EPA, but with various mixtures of ``R,''
``CR,'' and ``NR.'' In the final rule, EPA has retained the same
Supporting Information of the first section of the residue chemistry
table as proposed. However, EPA has adopted the commenters' suggestion
for a tiered format in the last two sections of the residue chemistry
table. After review, EPA believes the commenters' suggested tiered
approach is more suitable to antimicrobials than that proposed by EPA.
All three of the commenters' tables suggested that Tier I consist of a
``Screening-level dietary exposure assessment.'' Although an applicant
may opt to conduct a dietary exposure assessment, EPA does not consider
this to be a data requirement. Applicants often conduct a dietary
exposure assessment to understand the dietary risks before submitting
an application to EPA. If submitted, EPA would review the assumptions
used by the applicant and compare them to EPA's modeling. If the
applicant's modeling indicates that dietary risk is likely to meet or
exceed the Agency's level(s) of concern, the applicant may decide to
continue on to Tier II or III. Therefore, EPA has not added a
requirement to conduct a dietary exposure assessment.
    Both the Part 1 Table and the single table suggested that Tier II
consist of a ``Refined dietary exposure assessment.'' As is the case
for the commenter's suggested Tier I ``Screening-level dietary exposure
assessment,'' this is optional for the applicant; therefore, EPA has
not added a requirement to conduct a refined dietary exposure
assessment.
    Both the Part 1 Table and the single table suggested that Tier 3
consist of nature of residue on surface, bioaccumulation, magnitude of
residue, residue analytical method, and storage stability. These are
each addressed individually as follows:
    i. Nature of residue on surface. The Agency agrees that this study
is applicable and a valuable addition to the data set necessary to
support registration and risk assessment of antimicrobial uses on/in
food-contact surfaces and impregnated materials (treated articles). EPA
has added this study to the final residue chemistry data requirements
table in part 158, subpart W.
    ii. Bioaccumulation. EPA believes that the commenters intended that
this study apply only to fish and that the bioaccumulation study
required for ecological effects should substitute for the nature of the
residue on surface study for aquatic uses or indoor/outdoor raw
agricultural commodity uses. EPA has found that the fish
bioaccumulation study is often not useful for residue chemistry
purposes because characterization of fish residues is only required if
the bioconcentration (of total residues) factor is > 1,000. The fish
bioaccumulation study has not been adopted by EPA for residue
chemistry. Of much more use to residue chemistry and retained in this
final rule, are the fish metabolism and magnitude of the residue
studies in fish described in OPPTS Guideline 860.1400.
    iii. Magnitude of residue (MOR). Commenters proposed this study by
the very general title ``Magnitude of residue.'' EPA considers MOR to
be any study designed to quantify ``how much'' of the residues of
concern will result in food, on surfaces, in water, etc., following use
of an antimicrobial according to label directions. The commenters
stated in a footnote to this study that, in the case of food-contact
sanitizers and treated articles, MOR would consist of a migration
study. Because food-contact sanitizer and treated article uses comprise
at least 80 percent of all antimicrobial food uses, EPA has retained
the migration study and the food-handling study by name but has moved
them to a different tier. All the remaining proposed types of MOR
studies are much more rarely required due to characteristics such as
the use pattern and/or physicochemical properties of the antimicrobial
in question. For that reason, the following have been grouped as
``Higher tiered'' studies in the final rule: Nature of the residue in
plants, nature of the residue in livestock, residue analytical methods
for tolerance enforcement, multiresidue method testing, potable water,
fish, irrigated crops, meat/milk/poultry/eggs, crop field trials,
processed food or feed, and anticipated residues.
    iv. Residue analytical method. EPA agrees with the commenters that
an analytical method for data collection is required whenever magnitude
of the residue studies are required. The Agency has retained this study
in the final Residue Chemistry Table.
    v. Storage stability. EPA agrees with the commenters that storage
stability data are required whenever magnitude of the residue studies
are required. The Agency has retained this study in the final Residue
Chemistry Table.
    The Part 2 Table did not recommend requiring a Refined Dietary
Exposure Assessment. Rather, its Tier 2 consists of studies entitled
nature of the residue in commodity, nature of the residue in livestock,
residue analytical methods for enforcement of tolerances, multiresidue
analytical method, magnitude of the residue: In commodities, in water,
and in meat/milk/poultry/eggs, storage stability, and anticipated
residues. EPA agrees that all of these studies should be required and
has retained all of them in the highest tier in the final Residue
Chemistry Table. Note that two of the commenter-suggested studies
(nature of the residue in commodity and magnitude of the residue in
commodities) were considered applicable only to raw agricultural
commodities (RACs) treated via a fruit and vegetable rinse; whereas,
the analogous EPA data requirements apply to both crop plants and
metabolically-active RACs. The data requirements in EPA's final rule
easily subsume the studies suggested by a commenter in Part 2. The
commenters feel that EPA only has authority to require residue data for
RACs of plants treated by a fruit or vegetable rinse whereas EPA
interprets FIFRA and FFDCA, as amended by FQPA, to mean that data may
be required for any use if necessary to support registration of any use
under FIFRA (see Units XVI.A. and IV.).
    As evidenced by the recommendation to divide EPA's single proposed
data requirement table into two tables (Parts 1 and 2), the commenters
believe the data requirements are distinctly different depending on the
use pattern of interest. While this is sometimes the case, the Agency
has found that there is much overlap between which studies are
necessary to characterize the dietary exposure potentially resulting
from a given use. This is why the test notes provide the conditions
under which each study is required, likely to be required, or not
required. EPA has historically used and currently uses a single data
requirement table for each scientific discipline; doing so permits the
interrelationships between use pattern, tiering, and data needs to be
fully evident.
    The commenters did not account for data needed to estimate dietary
exposure associated with uses that do not require a FFDCA section 408
tolerance or exemption (see Unit XVI.A. and Unit IV.). The commenters
also did not account for data needed to estimate dietary exposure from
food residues inadvertently resulting from, but not limited to,
discharges of antimicrobial-treated water from indoor industries,
leaching from preserved lumber, or

treatment of food crops when a public health claim is made on the
label.

XVII. SAR and QSAR, and the OCSPP (formerly OPPTS) Integrated Testing
Vision

    This unit summarizes the significant public comments and EPA's
response to those comments. A more detailed discussion can be found in
the Response to Comments Document available in the docket to this rule.

A. Guidance on Policies, Procedures, and Processes

    1. Comment. A commenter asked EPA to provide clear guidance on its
policies, procedures, and processes on the use of alternative
technologies such as SAR and QSAR, and the WOE approach. In addition,
the commenter stated that EPA should also provide education and
training on these approaches.
    2. EPA's response. The Agency encourages applicants to create
submissions that include predictive techniques such as SAR and QSAR to
fulfill data requirements. As described in the white paper to the
proposed rule, entitled, ``Use of Structure-Activity Relationship (SAR)
Information and Quantitative SAR (QSAR) Modeling For Fulfilling Data
Requirements for Antimicrobial Pesticide Chemicals and Informing EPA's
Risk Management Process'' (see document ID number EPA-HQ-OPP-2008-0110-
0045), an important part of the applicant's submission is the
rationale. The rationale, or WOE evaluation, is the part of the
submission that explains the applicant's belief as to why and how the
predictive data would fulfill the data requirement. The WOE approach
requires a critical analysis of the entire body of available data for
consistency and biological plausibility. In support of a request that
predictive data be considered, the applicant would need to explain why
it believes the surrogate data or the modeling are appropriate for the
intended use and are of sufficient completeness and quality, and
therefore would fulfill the data requirement. The Agency would evaluate
each submission with a WOE rationale on a case-by-case basis.
    The general types of information that are considered appropriate
for a WOE approach would include:
     Sufficiency of data. Studies that completely characterize
both the effects and exposure of the agent have more credibility and
support than studies that contain data gaps.
     Quality of the data. Potentially relevant studies are
judged for quality and studies of high quality are given more weight
than those of lower quality.
     Evidence of causality. The degree of correlation between
the presence of an agent and some adverse effect is an important
consideration.
    Regarding SAR/QSAR, the white paper to the proposed rule (p. 30)
discusses the five criteria set by the OECD for evaluating a model. EPA
encourages submitters to follow the established criteria set by OECD,
and show how the model is validated for that particular pesticide
chemical structure as a measure of the model's applicability.
    Different computer software programs are used to estimate/predict
different hazards (see: http://www.epa.gov/oppt/sf/tools/methods.htm).
This means that predictive software models for different scientific
disciplines are not at the same level of development. The Agency has
long standing experience in predicting (modeling) physical-chemical
properties, environmental fate, ecotoxicity, and experience in
predicting carcinogenesis for certain classes of chemicals. However,
the Agency is still gaining experience to become familiar with
predictive approaches that look at other human health endpoints (e.g.,
reproductive, developmental), which have not been widely used at EPA.
Given the different stages of predictive software development, EPA
would expect to undertake a case-by-case evaluation of submitted WOEs.
EPA encourages the use of integrated approaches that combine the
knowledge from existing data bases about the chemical of interest with
data from appropriate surrogate chemicals.
    EPA agrees that guidance on the policies, procedures, and processes
for using alternative approaches such as SAR/QSAR is needed. In
developing such a guidance document for pesticides, EPA sought to
harmonize its approach with that of Canada's PMRA . The guidance
document was issued as a North American Free Trade Agreement guidance
document in 2012. This guidance document adheres to the five OECD
principles that were discussed in the white paper and is now considered
to be the definitive source of information for applicants seeking to
use SAR and QSAR approaches for fulfilling data requirements for
pesticide registration. For information, see http://www.epa.gov/oppfead1/international/naftatwg/guidance/guidance.htm.

B. Integrating SAR/QSAR Within the Data Requirements Rule

    1. Comments. One commenter argued that there should be an explicit
statement that SAR and QSAR can be considered to fulfill data
requirements. Another commenter had concerns on codifying the use of
SAR in 40 CFR part 158, subpart A since that would mean that ``SAR/QSAR
Techniques would be applicable to conventional, biochemical and
microbial, and antimicrobials pesticide chemicals.'' Another commenter
requested that SAR/QSAR be fully integrated within the rule.
    2. EPA's response. EPA has and will continue to consider accepting
SAR/QSAR to fulfill its data requirements on a case-by-case basis.
Acceptance would be based on the information provided and most
especially on the supporting rationale submitted to EPA. The Agency
would evaluate the information submitted to determine if the applicant
has provided information that is of sufficient quality and
completeness. The Agency notes that validation of QSAR models is
necessary before the predictions from those models can be fully
integrated into the testing requirements. To that end, QSAR models must
be inclusive of pesticide toxicology data and chemical structures.
Until these models become customized with pesticide information, full
incorporation of predictive tools likely will be limited to a case-by-
case basis.
    EPA agrees that if use of SAR/QSAR were to be codified in subpart
A, that it would be applicable to all pesticide chemicals. At this
time, EPA is not codifying the use of SAR and QSAR in subpart A.

XVIII. Guidelines

    This unit summarizes the significant public comments and EPA's
response to those comments. A more detailed discussion can be found in
the Response to Comments Document available in the docket to this rule.

A. Commenters' Concerns with Guidelines

    1. Comment. Several commenters indicated their belief that the
current Harmonized Guidelines have significant problems, which include:
     Lack of guidelines could create an unevenness from one
company to another in how the data requirements are applied.
     Data requirements for which guidelines are not available.
     Older, outdated guidelines that need revision.
     Draft guidelines that need to be finalized.
     Older exposure guidelines that do not include information
about the Human Studies Review Board.
     Guidelines that were adopted without the opportunity for
public comment.

    According to the commenters, lack of current guidelines could
create an unevenness from one company to another in how the data
requirements are applied. The commenter argued that the Agency needs to
provide current, consistent, and reliable guidance and standards for
each data requirement. The commenters recommended that EPA finalize all
of its guidelines before the final rule is published per the
recommendation from OMB.
    2. EPA's response. EPA's Harmonized Test Guidelines are publicly-
available at http://www.epa.gov/ocspp/pubs/frs/home/guidelin.htm. The
Harmonized Guidelines contain recommendations on how to conduct a study
that is most likely to provide the information needed by EPA for making
a registration decision.
    The Harmonized Guidelines are guidance. The guidelines themselves
do not impose mandatory requirements. Applicants are not required to
submit studies developed according to the guidelines to fulfill a data
requirement. However, EPA encourages applicants to use the guidelines.
These guidelines were developed to provide applicants, who would be
conducting the studies, with recognized approaches for developing high
quality data, guidance on evaluating and reporting data, definition of
terms, and suggested study protocols. It would not be possible to
address every conceivable circumstance that could occur when conducting
a particular study. Instead the guidelines provide a framework that
provides recommended approaches for conducting studies while offering
flexibility and accommodation for individual circumstances where
appropriate. EPA has reviewed and accepted many studies, on a case-by-
case basis, that were not conducted in accordance with current
guidelines, but which provided suitable information for risk assessment
purposes.
    Since guidelines cannot account for every conceivable circumstance,
EPA, for certain studies, proposed a ``required'' or ``highly
suggested'' protocol submission and review step in the test notes to
the tables in the proposed rule. Generally, these pertain to those
studies that are ``newer'' or have not been routinely conducted. Given
that the applicant community and contracting laboratories would have
less experience in conducting these kinds of ``newer'' studies,
protocol submission, review, and meetings about proposed protocols are
beneficial to both the applicant and EPA, and help assure that the
study submitted for review should provide the information needed by EPA
for its registration decision.
    EPA acknowledges that in some instances there are: Data
requirements for which guidelines are not available; outdated
guidelines that need revision; and draft guidelines that need to be
finalized. Ideally, up-to-date final guidelines would be available for
every data requirement. Up-to-date guidelines increase the possibility
that EPA will receive useful data and that applicants can produce such
data in the most cost-efficient and consistent manner. However, given
the rapidly evolving scientific methods for conducting toxicity,
exposure, and ecological studies with pesticides, study guidelines
often need frequent updating to include the latest techniques and
methods. Moreover, the need for openness and transparency means that
developing a guideline or updating an existing one can be a lengthy
process. In a letter to CropLife America (June 26, 2009), (Ref. 12) the
Agency discussed the timeframe for developing the Terrestrial Field
Dissipation Guideline (835.6100), which spanned 15 years. During that
time period, there were presentations to the SAP, at various symposia,
including ones conducted by the American Chemical Society and the
American Society of Agronomy, and to a workshop in Washington, DC co-
hosted by EPA and Canada's Pest Management Regulatory Agency.
    Thus, the reality is that test guidelines will always be a work in
progress. At the same time, EPA is implementing a regulatory program
under FIFRA and FFDCA section 408 under which it must make timely
decisions on the safety of pesticide products based on toxicity and
exposure testing. Guidance on optimal testing procedures remains an
Agency goal but the absence of testing guidelines is not a barrier to
the imposition of testing requirements necessary to make the required
statutory findings.
    In 2008, OMB, during its Executive Order 12866 review of the
proposed rule, recommended that certain draft guidelines be finalized
before publishing the Antimicrobial Data Requirements final rule. These
guidelines were:
     Applicator product use information (OPPTS 875.1700).
     Post application product use information (OPPTS 875.2700).
     Indoor surface residue dissipation (OPPTS 875.2300).
     Non-dietary ingestion (OPPTS 875.3000).
    In the proposed rule (73 FR 59382, October 8, 2008), EPA discussed
that the publicly-available versions of these draft guidelines were
available on the SAP portion of EPA's Web site http://www.epa.gov/scipoly/sap/meetings/1998/march/contents.htm. Since the two product use
information related guidelines (875.1700 and 875.2700) are expected to
provide similar guidance for the narrative descriptions that the
related data requirements call for, EPA intends to update them
together.
    The indoor surface residue dissipation draft guideline (875.2300)
will be updated before issued in final form to account for new advances
in how exposure is measured and modeled and to provide more information
on additional methods. EPA intends to revise the draft guideline to
expand the methods for antimicrobial uses, and has begun to work with
EPA's ORD to develop additional methods (e.g., one current project is
to develop guidance for testing in small scale air chambers). EPA is
also consulting with the Consumer Product Safety Commission (CPSC) to
review their sampling methods for similar products (e.g., chemicals
leaching from fabrics).
    Also, as previously discussed, the proposed data requirement
referencing the non-dietary ingestion guideline (identified as
875.3000) is not included in the final post-applicator exposure table
in Sec.  158.2270. As a result, that draft guideline is no longer
referenced in part 158. (See Unit XIII.D.).
    In addition, as noted in the proposed rule, EPA notes that it has
reviewed and accepted many studies, on a case-by-case basis, that were
not conducted in accordance with current final guidelines, but which
serve its needs and provide suitable information for risk assessment
purposes. The guidelines themselves do not impose mandatory
requirements. Instead, they present recognized standards for conducting
acceptable tests, guidance on evaluating and reporting data, definition
of terms, and suggested study protocols. The draft guidelines,
therefore, serve as a starting point for developing study protocols.
The Agency's scientists can also provide guidance to applicants,
registrants, or task forces on aspects of study design that is often
discussed at pre-protocol submission meetings. The Agency's scientists
are always willing to work with individual applicants or registrants to
develop study designs to fulfill data requirements.
    EPA acknowledges that the guidelines for dermal and inhalation
exposure studies need revisions to account for new advances in how
exposure is measured and modeled. To provide needed information to the
public and applicants, EPA will change the way these guidelines are
referenced on the Harmonized Guidelines Web site by

adding links to the SAP and Human Studies Review Board (HSRB) meetings
at which the changes needed to conduct one of these studies were
publicly discussed.
    Since the publication of the proposed rule on October 8, 2008, EPA
has worked to update and finalize a number of guidelines. In the
Federal Register of April 15, 2009 (74 FR 17479) (FRL-8352-8), EPA
issued a Notice of Availability describing updates to 16 environmental
fate guidelines.
    In the Federal Register of January 27, 2010 (75 FR 4380) (FRL-8437-
2), EPA published four draft product performance guidelines for comment
(i.e., 810.2000, 810.2100, 810.2200, and 810.2300). These four
guidelines were developed over an extended period of time with multiple
levels of review across divisions and program offices in EPA, expert
external peer review by the FIFRA SAP, and discussions with and
comments from the regulated community. After soliciting public comment
in 2010, EPA announced the availability of the final guidelines in the
Federal Register of March 16, 2012 (77 FR 15750) (FRL-9332-4). Many of
the technical changes described in these four guidelines have been in
use by the Agency for several years.
    Three additional Product Performance Guidelines (i.e., 810.2400,
810.2500, and 810.2600) published for public comment on September 15,
2011 (76 FR 57031) (FRL-8879-1), and in the Federal Register of June
27, 2012 (77 FR 38280) (FRL-9349-5), EPA announced the availability of
the final guidelines.
    Also in the Federal Register of June 27, 2012 (77 FR 38282) (FRL-
9333-1), EPA announced the availability of 26 Ecological Effects Test
Guidelines in Series 850, and Groups B, C, D and F. In finalizing the
guidelines, EPA changed the numbering and/or titles of certain
guidelines, and split or merged other guidelines. EPA continues to work
to revise the remaining Ecological Effects Test Guidelines, Group A,
and anticipates finalizing many of these guidelines in 2013.
    Before finalizing a guideline, EPA provides many opportunities for
public comment. EPA's commitment to transparency is not new.
Transparency allows all stakeholders to know what, how, and why EPA is
adopting a guideline. EPA's procedures for developing a guideline is
described in a Notice of Availability that published on August 28, 1996
(61 FR 44308) (FRL-5390-7):
     Guidelines under development (whether new or being
substantially revised) are made available for public comment.
     Guidelines under development (whether new or being
substantially revised) undergo an external peer review process. Most
commonly, the peer review process would be a review by the FIFRA SAP.
     Reformatted guidelines (no substantial revisions) are not
subject to review and comment.
     Public review and comment is also used when EPA guidelines
are being harmonized with OECD guidelines.

B. Harmonization of Guidelines With OECD

    1. Comment. EPA should harmonize its guidelines with those of OECD.
    2. EPA's response. EPA agrees with this comment and is continuing
to harmonize guidelines, to the extent practicable, as they are
revised. As noted on its Web site http://www.epa.gov/pesticides/science/guidelines.htm, EPA has several harmonization activities
underway with the OECD. The Master List of Harmonized Test Guidelines
includes a reference to an OECD guideline, once harmonized. All
harmonized OECD test guidelines (http://www.epa.gov/epahome/exitepa.htm) fall under the OECD Mutual Acceptance of Data decision,
which calls for acceptance for regulatory use by all OECD member
nations. Additionally, under 40 CFR 158.70(d)(2), acceptance of testing
conducted in accordance with OECD protocols is described.
    Harmonized test guidelines reduce the burden on chemical producers
and conserve scientific resources, including the minimal use of
laboratory test animals. They also form a basis for work sharing and
cooperation among all OECD countries. U.S. experts are engaged in
harmonization activities through OECD to revise toxicology and
ecotoxicology test guidelines. These revisions will emphasize
reduction, refinement, or replacement of animal testing, while
incorporating the latest advances in science. Animal welfare concerns
and international regulatory needs are being considered in the course
of these revisions of the test guidelines. In addition, EPA is actively
engaged in OECD's development and harmonization efforts for guidelines
to address environmental fate, endocrine disruptor screening, and
efficacy of antimicrobial pesticides.
    Tests conducted in accordance with the requirements and
recommendations of the applicable OECD protocols can be used to develop
data necessary to fulfill the data requirements. However, some of the
OECD recommended test standards, such as test duration and selection of
test species, are less restrictive than those recommended by EPA. When
using OECD protocols, applicants should be careful to observe the test
standards so that the data generated will satisfy the EPA data
requirements.

C. Guidelines Specific to Antimicrobials

    1. Comment. The commenter claimed that guidelines specific to
antimicrobials are needed.
    2. EPA's response. EPA agrees that for certain scientific
disciplines or certain studies antimicrobial-specific guidance may be
needed. The data required to demonstrate product performance would be
very different for an insect repellent or a termiticide versus that
needed for sanitizers and disinfectants. Exposure studies could be
conducted differently for an antimicrobial used in a food-processing
plant versus a conventional pesticide sprayed on an agricultural field.
Exposure studies could also be conducted via the same method: A spray
can with an insecticide is assessed using the same techniques as a
spray can with a disinfectant, with any differences in the assessment
being attributed to actual use conditions, such as, indoors versus
outdoors or surfaces sprayed. For other scientific disciplines such as
toxicology or product chemistry, generally, with a few exceptions, the
guidance would be the same. A carcinogenicity, developmental, or
reproductive toxicity study would be conducted similarly for an
antimicrobial or a conventional pesticide. However, as noted in Unit
X.F., the Ames assay may not be useful for assessment of mutagenic
potential of antimicrobial pesticides.

XIX. Endangered Species Assessments

    This unit summarizes the significant public comments and EPA's
response to those comments. A more detailed discussion can be found in
the Response to Comments Document available in the docket to this rule.

A. Endangered Species Assessment for Antimicrobials

    1. Comment. The commenter argued that EPA needs to recognize the
manner in which antimicrobials may result in environmental exposure and
the regulations under statutes other than FIFRA in order to promote an
effective and efficient approach to regulating antimicrobial pesticides
with regard to endangered and threatened species. According to the
commenter, antimicrobials are not applied directly to the environment,
but environmental exposures from antimicrobial pesticides result from
point-source discharges or

slow release from pesticide-containing materials.
    2. EPA's response. EPA agrees that there are differences between
antimicrobial pesticides and agricultural pesticides. As discussed in
the proposed rule (October 8, 2008, 73 FR 59425), for agricultural
pesticides, there is generally greater specificity relative to where a
pesticide may be used compared to antimicrobial pesticides.
Agricultural pesticides are typically used on crops. As part of its
endangered and threatened species assessment, EPA extracts information
on county-level crop occurrence and acreage within counties of
particular crops from the most recent USDA National Agricultural
Statistics Services' Census of Agriculture. Because antimicrobial
pesticides are typically not applied directly to the environment, it is
easier to delineate and overlay agricultural pesticide use with
endangered or threatened species locations than to delineate and
overlay antimicrobial pesticides use. Nevertheless, wood preservatives,
antifoulant paints and coatings, and other antimicrobial uses,
including uses in swimming pool water, industrial slimicides used in
recirculating water cooling towers, and paper mills, have the potential
for environmental exposures. The Agency is working to refine its
endangered species assessment for antimicrobial pesticides to account
for the unique mechanisms involved in application and use of
antimicrobial pesticides, and the different routes through which
antimicrobial pesticides enter the environment.
    EPA recognizes that antimicrobials, like any other pesticide
product, may be subject to other Federal, State and local laws. FIFRA
requires that, before a pesticide may be lawfully sold or distributed
in the United States, the product must be registered by EPA, unless the