Carbaryl; Order Denying NRDC's Petition to Revoke Tolerances, 64229-64246 [E8-25693]

Agencies

• ENVIRONMENTAL PROTECTION AGENCY

[Federal Register Volume 73, Number 210 (Wednesday, October 29, 2008)]
[Rules and Regulations]
[Pages 64229-64246]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E8-25693]



[[Page 64229]]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[EPA-HQ-OPP-2008-0347; FRL-8388-1]


Carbaryl; Order Denying NRDC's Petition to Revoke Tolerances

AGENCY: Environmental Protection Agency (EPA).

ACTION: Order.

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SUMMARY: In this Order, EPA denies a petition requesting that EPA 
revoke all pesticide tolerances for carbaryl under section 408(d) of 
the Federal Food, Drug, and Cosmetic Act (FFDCA). The petition was 
filed on January 10, 2005, by the Natural Resources Defense Council 
(NRDC).

DATES: This Order is effective October 29, 2008. Objections and 
requests for hearings must be received on or before December 29, 2008, 
and must be filed in accordance with the instructions provided in 40 
CFR part 178 (see also Unit I.C. of the SUPPLEMENTARY INFORMATION).

ADDRESSES: EPA has established a docket for this action under docket 
identification (ID) number EPA-HQ-OPP-2008-0347. To access the 
electronic docket, go to https://www.regulations.gov, select ``Advanced 
Search,'' then ``Docket Search.'' Insert the docket ID number where 
indicated and select the ``Submit'' button. Follow the instructions on 
the regulations.gov website to view the docket index or access 
available documents. All documents in the docket are listed in the 
docket index available in regulations.gov. Although listed in the 
index, some information is not publicly available, e.g., Confidential 
Business Information (CBI) or other information whose disclosure is 
restricted by statute. Certain other material, such as copyrighted 
material, is not placed on the Internet and will be publicly available 
only in hard copy form. Publicly available docket materials are 
available in the electronic docket at https://www.regulations.gov, or, 
if only available in hard copy, at the OPP Regulatory Public Docket in 
Rm. S-4400, One Potomac Yard (South Bldg.), 2777 S. Crystal Dr., 
Arlington, VA. The Docket Facility is open from 8:30 a.m. to 4 p.m., 
Monday through Friday, excluding legal holidays. The Docket Facility 
telephone number is (703) 305-5805.

FOR FURTHER INFORMATION CONTACT: Christina Scheltema, Special Review 
and Reregistration Division (7508P), Office of Pesticide Programs, 
Environmental Protection Agency, 1200 Pennsylvania Ave., NW., 
Washington, DC 20460-0001; telephone number: 703-308-2201; e-mail 
address: scheltema.christina@epa.gov.

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me?

    In this document, EPA denies a petition by the NRDC to revoke 
pesticide tolerances. This action may be of interest to agricultural 
producers, food manufacturers, or pesticide manufacturers. Potentially 
affected entities may include, but are not limited to those engaged in 
the following activities:
     Crop production (NAICS code 111), e.g., agricultural 
workers; greenhouse, nursery, and floriculture workers; farmers.
     Animal production (NAICS code 112), e.g., cattle ranchers 
and farmers, dairy cattle farmers, livestock farmers.
     Food manufacturing (NAICS code 311), e.g., agricultural 
workers; farmers; greenhouse, nursery, and floriculture workers; 
ranchers; pesticide applicators.
     Pesticide manufacturing (NAICS code 32532), e.g., 
agricultural workers; commercial applicators; farmers; greenhouse, 
nursery, and floriculture workers; residential users.
    This listing is not intended to be exhaustive, but rather to 
provide a guide for readers regarding entities likely to be affected by 
this action. Other types of entities not listed in this unit could also 
be affected. The North American Industrial Classification System 
(NAICS) codes have been provided to assist you and others in 
determining whether this action might apply to certain entities. If you 
have any questions regarding the applicability of this action to a 
particular entity, consult the person listed under FOR FURTHER 
INFORMATION CONTACT.

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

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

C. Can I File an Objection or Hearing Request?

    Under section 408(g) of FFDCA, any person may file an objection to 
any aspect of this regulation and may also request a hearing on those 
objections. You must file your objection or request a hearing on this 
regulation in accordance with the instructions provided in 40 CFR part 
178. To ensure proper receipt by EPA, you must identify docket ID 
number EPA-HQ-OPP-2008-0347 in the subject line on the first page of 
your submission. All requests must be in writing, and must be mailed or 
delivered to the Hearing Clerk as required by 40 CFR part 178 on or 
before December 29, 2008.
    In addition to filing an objection or hearing request with the 
Hearing Clerk as described in 40 CFR part 178, please submit a copy of 
the filing that does not contain any CBI for inclusion in the public 
docket that is described in ADDRESSES. Information not marked 
confidential pursuant to 40 CFR part 2 may be disclosed publicly by EPA 
without prior notice. Submit this copy, identified by docket ID number 
EPA-HQ-OPP-2008-0347, by one of the following methods:
     Federal eRulemaking Portal: https://www.regulations.gov. 
Follow the on-line instructions for submitting comments.
     Mail: Office of Pesticide Programs (OPP) Regulatory Public 
Docket (7502P), Environmental Protection Agency, 1200 Pennsylvania 
Ave., NW., Washington, DC 20460-0001.
     Delivery: OPP Regulatory Public Docket (7502P), 
Environmental Protection Agency, Rm. S-4400, One Potomac Yard (South 
Bldg.), 2777 S. Crystal Dr., Arlington, VA. Deliveries are only 
accepted during the Docket's normal hours of operation (8:30 a.m. to 4 
p.m., Monday through Friday, excluding legal holidays). Special 
arrangements should be made for deliveries of boxed information. The 
Docket Facility telephone number is (703) 305-5805.

II. Introduction

A. What Action Is the Agency Taking?

    The NRDC filed a petition dated January 10, 2005 with EPA which, 
among other things, requested that EPA revoke all tolerances for the 
pesticide carbaryl established under section 408 of the FFDCA, 21 
U.S.C. 346a (Ref. 1) This Order denies that aspect of the petition that 
sought the revocation of the carbaryl tolerances. This Order also 
denies NRDC's petition to cancel carbaryl pet collar registrations 
submitted as part of NRDC's comments on the N-methyl carbamate (NMC)

[[Page 64230]]

cumulative assessment and dated November 26, 2007, because NRDC is 
arguing that exposure to carbaryl pet collars makes the cumulative 
risks presented by carbaryl unsafe (Ref. 2).

B. What Is the Agency's Authority for Taking This Action?

    Under section 408(d)(4) of the FFDCA, EPA is authorized to respond 
to a section 408(d) petition to revoke tolerances either by issuing a 
final rule revoking the tolerances, issuing a proposed rule, or issuing 
an order denying the petition. (21 U.S.C. 346a(d)(4)).

III. Statutory and Regulatory Background

A. FFDCA/FIFRA and Applicable Regulations

    1. In general. EPA establishes maximum residue limits, or 
``tolerances,'' for pesticide residues in food and feed commodities 
under section 408 of the FFDCA. (21 U.S.C. 346a). Without such a 
tolerance or an exemption from the requirement of a tolerance, a food 
containing a pesticide residue is ``adulterated'' under section 402 of 
the FFDCA and may not be legally moved in interstate commerce. (21 
U.S.C. 331, 342). Monitoring and enforcement of pesticide tolerances 
are carried out by the U.S. Food and Drug Administration (FDA) and the 
U.S. Department of Agriculture (USDA). Section 408 was substantially 
rewritten by the Food Quality Protection Act of 1996 (FQPA), which 
added the provisions discussed below establishing a detailed safety 
standard for pesticides, additional protections for infants and 
children, and the estrogenic substances screening program. (Public Law 
104-170, 110 Stat. 1489 (1996)).
    EPA also regulates pesticides under the Federal Insecticide, 
Fungicide, and Rodenticide Act (FIFRA), (7 U.S.C. 136 et seq). While 
the FFDCA authorizes the establishment of legal limits for pesticide 
residues in food, FIFRA requires the approval of pesticides prior to 
their sale and distribution, (7 U.S.C. 136a(a)), and establishes a 
registration regime for regulating the use of pesticides. FIFRA 
regulates pesticide use in conjunction with its registration scheme by 
requiring EPA review and approval of pesticide labels and specifying 
that use of a pesticide inconsistent with its label is a violation of 
federal law. (7 U.S.C. 136j(a)(2)(G)). In the FQPA, Congress integrated 
action under the two statutes by requiring that the safety standard 
under the FFDCA be used as a criterion in FIFRA registration actions as 
to pesticide uses which result in dietary risk from residues in or on 
food, (7 U.S.C. 136(bb)), and directing that EPA coordinate, to the 
extent practicable, revocations of tolerances with pesticide 
cancellations under FIFRA. (21 U.S.C. 346a(l)(1)).
    2. Safety standard for pesticide tolerances. A pesticide tolerance 
may only be promulgated or left in effect by EPA if the tolerance is 
``safe.'' (21 U.S.C. 346a(b)(2)(A)(i)). This standard applies both to 
petitions to establish and petitions to revoke tolerances. ``Safe'' is 
defined by the statute to mean that ``there is a reasonable certainty 
that no harm will result from aggregate exposure to the pesticide 
chemical residue, including all anticipated dietary exposures and all 
other exposures for which there is reliable information.'' (21 U.S.C. 
346a(b)(2)(A)(ii)). Section 408(b)(2)(D) directs EPA, in making a 
safety determination, to:
    consider, among other relevant factors--...
    (v) available information concerning the cumulative effects of 
such residues and other substances that have a common mechanism of 
toxicity; and
    (vi) available information concerning the aggregate exposure 
levels of consumers (and major identifiable subgroups of consumers) 
to the pesticide chemical residue and to other related substances, 
including dietary exposure under the tolerance and all other 
tolerances in effect for the pesticide chemical residue, and 
exposure from other non-occupational sources;

(21 U.S.C. 346a(b)(2)(D)(v), (vi) and (viii)).

    EPA must also consider, in evaluating the safety of tolerances, 
``safety factors which . . . are generally recognized as appropriate 
for the use of animal experimentation data.'' (21 U.S.C. 
346a(b)(2)(D)(ix).
    Risks to infants and children are given special consideration. 
Specifically, section 408(b)(2)(C) states that EPA:
    shall assess the risk of the pesticide chemical based on--
    (II) available information concerning the special susceptibility 
of infants and children to the pesticide chemical residues, 
including neurological differences between infants and children and 
adults, and effects of in utero exposure to pesticide chemicals; and
    (III) available information concerning the cumulative effects on 
infants and children of such residues and other substances that have 
a common mechanism of toxicity. ...

 (21 U.S.C. 346a(b)(2)(C)(i)(II) and (III)).

    This provision also creates a presumptive additional safety factor 
for the protection of infants and children. Specifically, it directs 
that ``[i]n the case of threshold effects, ... an additional tenfold 
margin of safety for the pesticide chemical residue and other sources 
of exposure shall be applied for infants and children to take into 
account potential pre- and post-natal toxicity and completeness of the 
data with respect to exposure and toxicity to infants and children.'' 
(21 U.S.C. 346a(b)(2)(C)). EPA is permitted to ``use a different margin 
of safety for the pesticide chemical residue only if, on the basis of 
reliable data, such margin will be safe for infants and children.'' 
(Id.). The additional safety margin for infants and children is 
referred to throughout this Order as the ``FQPA Safety Factor.''
    3. Procedures for establishing, amending, or revoking tolerances. 
Tolerances are established, amended, or revoked by rulemaking under the 
unique procedural framework set forth in the FFDCA. Generally, a 
tolerance rulemaking is initiated by the party seeking to establish, 
amend, or revoke a tolerance by means of filing a petition with EPA. 
(See 21 U.S.C. 346a(d)(1)). EPA publishes in the Federal Register a 
notice of the petition filing and requests public comment. (21 U.S.C. 
346a(d)(3)). After reviewing the petition, and any comments received on 
it, EPA may issue a final rule establishing, amending, or revoking the 
tolerance, issue a proposed rule to do the same, or deny the petition. 
(21 U.S.C. 346a(d)(4)).
    Once EPA takes final action on the petition by establishing, 
amending, or revoking the tolerance or denying the petition, any party 
may file objections with EPA and seek an evidentiary hearing on those 
objections. (21 U.S.C. 346a(g)(2)). Objections and hearing requests 
must be filed within 60 days. (Id.). The statute provides that EPA 
shall ``hold a public evidentiary hearing if and to the extent the 
Administrator determines that such a public hearing is necessary to 
receive factual evidence relevant to material issues of fact raised by 
the objections.'' (21 U.S.C. 346a(g)(2)(B). EPA regulations make clear 
that hearings will only be granted where it is shown that there is ``a 
genuine and substantial issue of fact,'' the requestor has identified 
evidence ``which, if established, resolve one or more of such issues in 
favor of the requestor,'' and the issue is ``determinative'' with 
regard to the relief requested. (40 CFR 178.32(b)). EPA's final order 
on the objections is subject to judicial review. (21 U.S.C. 
346a(h)(1)).
    4. Tolerance reassessment and FIFRA reregistration. The FQPA 
required that EPA reassess the safety of all pesticide tolerances 
existing at the time of its enactment. (21 U.S.C. 346a(q)). EPA was 
given 10 years to reassess the

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approximately 10,000 tolerances in existence in 1996. In this 
reassessment, EPA was required to review existing pesticide tolerances 
under the new ``reasonable certainty that no harm will result'' 
standard set forth in section 408(b)(2)(A)(i). (21 U.S.C. 
346a(b)(2)(A)(i)). This reassessment was substantially completed by the 
August 3, 2006 deadline. Tolerance reassessment was generally handled 
in conjunction with a similar program involving reregistration of 
pesticides under FIFRA. (7 U.S.C. 136a-1). Reassessment and 
reregistration decisions were generally combined in a document labeled 
a Reregistration Eligibility Decision (``RED'').

B. EPA's Approach to Dietary Risk Assessment

    EPA performs a number of analyses to determine the risks from 
aggregate exposure to pesticide residues. A short summary is provided 
below to aid the reader. For further discussion of the regulatory 
requirements of section 408 of the FFDCA and a complete description of 
the risk assessment process, see https://www.epa.gov/fedrgstr/EPA-PEST/
1999/January/Day-04/p34736.htm.(64 FR 162)
    To assess the risk of a pesticide tolerance, EPA combines 
information on pesticide toxicity with information regarding the route, 
magnitude, and duration of exposure to the pesticide. The risk 
assessment process involves three distinct steps: (1) identification of 
the toxicological hazards posed by a pesticide and determination of the 
exposure ``level of concern'' for humans; (2) estimation of human 
exposure; and (3) characterization of human risk based on comparison of 
human exposure to the level of concern.
    1. Hazard identification and determination of the level of concern. 
Any risk assessment begins with an evaluation of a chemical's inherent 
properties, and whether those properties have the potential to cause 
adverse effects (i.e., hazard identification). EPA then evaluates the 
hazards to determine the most sensitive and appropriate adverse effect 
of concern, based on factors such as the effect's relevance to humans 
and the likely routes of exposure. Once a pesticide's potential hazards 
are identified, EPA determines a toxicological level of concern for 
evaluating the risk posed by human exposure to the pesticide. In this 
step of the risk assessment process, EPA essentially evaluates the 
levels of exposure to the pesticide at which effects might occur. An 
important aspect of this determination is assessing the relationship 
between exposure (dose) and response (often referred to as the dose-
response analysis). Another aspect is the determination of whether the 
effect is associated with a threshold dose (i.e., the effect is seen 
only at or above a certain dose) or whether the effect can occur at any 
dose (such as some tumors).
    In evaluating a chemical's dietary risks for threshold effects, EPA 
uses a reference dose (RfD) approach, which involves a number of 
considerations including:
     A 'point of departure'(PoD) - the value from a dose-
response curve that is at the low end of the observable data (the no 
observed adverse effect level, or NOAEL, the lowest-observed adverse 
effect level or LOAEL, or an extrapolated benchmark dose) and that is 
the dose serving as the 'starting point' in extrapolating a risk to the 
human population;
     An uncertainty factor to address the potential for a 
difference in toxic response between humans and animals used in 
toxicity tests (i.e., interspecies extrapolation);
     An uncertainty factor to address the potential for 
differences in sensitivity in the toxic response across the human 
population (for intraspecies extrapolation); and
     The need for an additional safety factor to protect 
infants and children, as specified in FFDCA section 408(b)(2)(C).
    EPA uses the chosen PoD to calculate a safe dose or RfD. The RfD is 
calculated by dividing the chosen PoD by all applicable safety or 
uncertainty factors. Typically in EPA risk assessments, a combination 
of safety or uncertainty factors providing at least a hundredfold 
(100X) margin of safety is used: 10X to account for interspecies 
extrapolation and 10X to account for intraspecies extrapolation. 
Further, in evaluating the dietary risks for pesticide chemicals, an 
additional safety factor of 10X is presumptively applied to protect 
infants and children, unless reliable data support selection of a 
different factor. In implementing FFDCA section 408, EPA also 
calculates a variant of the RfD referred to as a population adjusted 
dose (PAD). The PAD is the RfD divided by any portion of the children's 
safety factor that does not correspond to one of the traditional 
additional uncertainty/safety factors used in general Agency risk 
assessment. The reason for calculating PADs is so that other parts of 
the Agency, which are not governed by FFDCA section 408, can, when 
evaluating the same or similar substances, easily identify which 
aspects of a pesticide risk assessment are a function of the particular 
statutory commands in FFDCA section 408. For acute assessments, the 
risk is expressed as a percentage of a maximum acceptable dose or the 
acute PAD (i.e., the acute dose which EPA has concluded will be 
``safe''). As discussed below in Unit V.C., dietary exposures greater 
than 100 percent of the acute PAD are generally cause for concern and 
would be considered ``unsafe'' within the meaning of FFDCA section 
408(b)(2)(B). Throughout this document general references to EPA's 
calculated safe dose are denoted as an acute PAD, or aPAD, because the 
relevant point of departure for carbaryl is based on an acute risk 
endpoint.
    In evaluating a chemical's dietary risk for non-threshold effects, 
such as cancer; EPA's default approach is to extrapolate a Q1* from the 
dose-response curve as a measure of cancer potency, and then to use 
this Q1* value in conjunction with estimated dietary exposure to 
estimate the probability of occurrence of additional adverse effects. 
The Q1*is the 95th percentile upper confidence limit from a tumor dose 
response curve extrapolated using a linear low-dose model. For non-
threshold dietary cancer risks, EPA generally considers cancer risk to 
be negligible if the probability of increased cancer cases falls within 
the range of 1 in 1 million.
    Animal studies show that carbaryl, like other NMC pesticides, 
causes transient, reversible inhibition of cholinesterase activity in 
brain, red blood cells, and plasma across all tested routes of 
exposure. Developmental toxicity was seen in rats and rabbits treated 
with carbaryl during gestation; effects included decreased fetal weight 
and incomplete ossification (bone formation). A carbaryl rat 
reproductive toxicity study showed decreased pup survival, and a rat 
developmental neurotoxicity study showed changes in fetal brain 
morphometry. In addition, a comparative cholinesterase study shows that 
young animals had increased sensitivity, compared with adults, to 
inhibition of brain cholinesterase from carbaryl. EPA used endpoints 
from the comparative cholinesterase study to assess human health risk 
in both the single chemical risk assessment for carbaryl and in the 
cumulative risk assessment for the NMC pesticides. Carbaryl is 
considered to be ``likely to be carcinogenic in humans'' based on 
tumors in male mice and EPA utilized the Agency default low-dose linear 
extrapolation (Q1*) approach to quantify cancer risk.
    2. Estimating human exposure levels. Pursuant to section 408(b) of 
the FFDCA, EPA has evaluated carbaryl dietary risks based on 
``aggregate

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exposure'' to carbaryl. By ``aggregate exposure,'' EPA is referring to 
exposure to carbaryl alone by multiple pathways of exposure, including 
residues in food and water and exposure from use of carbaryl products 
in residential settings. EPA uses available data, together with 
assumptions designed to be protective of public health and standard 
analytical methods, to produce separate estimates of exposure for a 
highly exposed subgroup of the general population, for each potential 
pathway and route of exposure. For acute risks, EPA then calculates 
potential aggregate exposure and risk by using probabilistic techniques 
to combine distributions of potential exposures in the population for 
the dietary pathway, and uses single point estimates for the 
residential component in calculating aggregate exposure. For dietary 
analyses, the relevant sources of potential exposure to carbaryl are 
from the ingestion of residues in food and drinking water.
    The Agency uses a combination of monitoring data and predictive 
models to evaluate environmental exposure of humans to carbaryl, which 
may occur from ingesting carbaryl residues in food or drinking water, 
or from using products containing carbaryl in residential settings. 
These are described below.
    a. Exposure from food. Data on the residues of carbaryl in foods 
are available from a variety of sources. One of the primary sources of 
the data comes from federally-conducted surveys, including the 
Pesticide Data Program (PDP) conducted by the USDA. Further, market 
basket studies, which are typically performed by registrants, can 
provide additional residue data. These data generally provide a 
characterization of pesticide residues in or on foods consumed by the 
U.S. population that closely approximates real world exposures because 
they are sampled closer to the point of consumption in the chain of 
commerce than field trial data, which are generated to establish the 
maximum level of legal residues that could result from maximum 
permissible use of the pesticide. In certain circumstances, EPA will 
rely on field trial data, as it can provide more accurate exposure 
estimates. EPA estimated dietary exposure to carbaryl using residue 
data from a variety of sources, including USDA and FDA monitoring and 
crop field trial studies. These residue data were refined based on 
relevant processing factors. EPA also took into account information on 
the extent to which crops which may be treated with carbaryl are 
actually so treated.
    EPA uses a computer program, the Dietary Exposure Evaluation Model 
(DEEM), and the USDA Food Commodity Intake database (FCID), to estimate 
exposure by combining data on human consumption amounts with residue 
values in food commodities. DEEM-FCIDTM also compares 
exposure estimates to appropriate RfD or PAD values to estimate risk. 
EPA uses DEEM-FCIDTM to estimate exposure for the general 
U.S. population as well as for 32 subgroups based on age, sex, 
ethnicity, and region. DEEM-FCIDTM allows EPA to process 
extensive volumes of data on human consumption amounts and residue 
levels in making risk estimates. Matching consumption and residue data, 
as well as managing the thousands of repeated analyses of the 
consumption database conducted under probabilistic risk assessment 
techniques, requires the use of a computer.
    DEEM-FCIDTM contains consumption and demographic 
information on the individuals who participated in the USDA's Combined 
Survey of Food Intake by Individuals (CSFII) in 1994-1996 and 1998. The 
1998 survey was a special survey required by the FQPA to supplement the 
number of children survey participants. DEEM-FCIDTM also 
contains ``recipes'' that convert foods as consumed (e.g., pizza) back 
into their component raw agricultural commodities (e.g., wheat from 
flour, or tomatoes from sauce, etc.). This is necessary because residue 
data are generally gathered on raw agricultural commodities rather than 
on finished ready-to-eat food. Data on residue values for a particular 
pesticide and the RfD or PADs for that pesticide are inputs to the 
DEEM-FCIDTM program to estimate exposure and risk.
    For carbaryl's assessment, EPA used DEEM-FCIDTM to 
calculate risk estimates based on a probabilistic distribution. DEEM-
FCIDTM combines the full range of residue values for each 
food with the full range of data on individual consumption amounts to 
create a distribution of exposure and risk levels. More specifically, 
DEEM-FCIDTM creates this distribution by calculating an 
exposure value for each reported day of consumption per person 
(``person/day'') in USDA's CSFII, assuming that all foods potentially 
bearing the pesticide residue contain such residue at the chosen value. 
The exposure amounts for the thousands of person/days in the CSFII are 
then collected in a frequency distribution. EPA also uses DEEM-
FCIDTM to compute a distribution taking into account both 
the full range of data on consumption levels and the full range of data 
on potential residue levels in food. Combining consumption and residue 
levels into a distribution of potential exposures and risk requires use 
of probabilistic techniques.
    Probabilistic analysis is used to predict the frequency with which 
variations of a given event will occur. By taking into account the 
actual distribution of possible consumption and pesticide residue 
values, probabilistic analysis for pesticide exposure assessments 
``provides more accurate information on the range and probability of 
possible exposure and their associated risk values'' (Ref. 3). In 
capsule, a probabilistic pesticide exposure analysis constructs a 
distribution of potential exposures based on data on consumption 
patterns and residue levels and provides a ranking of the probability 
that each potential exposure will occur. People consume differing 
amounts of the same foods, including none at all, and a food will 
contain differing amounts of a pesticide residue, including none at 
all.
    The probabilistic technique that DEEM-FCIDTM uses to 
combine differing levels of consumption and residues involves the 
following steps:
    (1) Identification of any food(s) that could bear the residue in 
question for each person/day in the CSFII;
    (2) Calculation of an exposure level for each of the thousands of 
person/days in the CSFII database, based on the foods identified in 
Step 1 by randomly selecting residue values for the foods from 
the residue database;
    (3) Repetition of Step 2 up to one thousand times for each 
person/day; and
    (4) Collection of all of the hundreds of thousands of potential 
exposures estimated in Steps  2 and 3 in a frequency 
distribution.
    The resulting probabilistic assessment presents a range of 
exposure/risk estimates.
    b. Exposure from water. EPA may use field monitoring data and/or 
simulation water exposure models to generate pesticide concentration 
estimates in drinking water. Monitoring and modeling are both important 
tools for estimating pesticide concentrations in water and can provide 
different types of information. Monitoring data can provide estimates 
of pesticide concentrations in water that are representative of the 
specific agricultural or residential pesticide practices in specific 
locations, under the environmental conditions associated with a 
sampling design (i.e., the locations of sampling, the times of the year 
samples were taken, and the frequency by which samples were collected). 
Although monitoring data

[[Page 64233]]

can provide a direct measure of the concentration of a pesticide in 
water, it does not always provide a reliable basis for estimating 
spatial and temporal variability in exposures because sampling may not 
occur in areas with the highest pesticide use, and/or when the 
pesticides are being used and/or at an appropriate sampling frequency 
to detect high concentrations of a pesticide that occur over the period 
of a day to several days.
    Because of the limitations in most monitoring studies, EPA's 
standard approach is to use simulation water exposure models as the 
primary means to estimate pesticide exposure levels in drinking water. 
EPA's computer models use detailed information on soil properties, crop 
characteristics, and weather patterns to estimate water concentrations 
in vulnerable locations where the pesticide could be used according to 
its label. (69 FR 30042, May 26, 2004). These models calculate 
estimated water concentrations of pesticides using laboratory data that 
describe how fast the pesticide breaks down to other chemicals and how 
it moves in the environment at these vulnerable locations. The modeling 
provides an estimate of pesticide concentrations in ground and surface 
water. Daily concentrations can be estimated continuously over long 
periods of time, and for places that are of most interest for any 
particular pesticide.
    EPA relies on models it has developed for estimating pesticide 
concentrations in both surface water and ground water. Typically EPA 
uses a two-tiered approach to modeling pesticide concentrations in 
surface and ground water. If the first tier model suggests that 
pesticide levels in water may be unacceptably high, a more ined model 
is used as a second tier assessment. For surface water assessments, the 
second tier model is actually a combination of two models: The 
Pesticide Root Zone Model (PRZM) and the Exposure Analysis Model System 
(EXAMS).
    A detailed description of the models routinely used for exposure 
assessment is available from the EPA web site: https://www.epa.gov/
oppefed1/models/water/index.htm. These models provide a means for EPA 
to estimate daily pesticide concentrations in surface water sources of 
drinking water (a reservoir) using local soil, site, hydrology, and 
weather characteristics along with pesticide application and 
agricultural management practices, and pesticide environmental fate and 
transport properties. Consistent with the recommendations of the FIFRA 
Science Advisory Panel (SAP), EPA also considers percent cropped area 
factors (PCA) which takes into account the potential extent of cropped 
areas that could be treated with pesticides in a particular area. The 
PRZM and EXAMS models used by EPA were developed by EPA's Office of 
Research and Development (ORD), and are used by many international 
pesticide regulatory agencies to estimate pesticide exposure in surface 
water. EPA's use of the percent cropped area factors and the Index 
Reservoir scenario was reviewed by the FIFRA SAP in 1999 and 1998, 
respectively (Refs. 4 and 5).
    In modeling potential surface water concentrations, EPA attempts to 
model areas of the country that are highly vulnerable to surface water 
contamination rather than simply model ``typical'' locations occurring 
across the nation. Consequently, EPA models exposures occurring in 
small highly agricultural watersheds in different growing areas 
throughout the country. The scenarios are designed to capture residue 
levels in drinking water from reservoirs with small watersheds with a 
large percentage of land use in agricultural production. EPA believes 
these assessments are likely reflective of a small subset of the 
watersheds across the country that maintain drinking water reservoirs, 
representing a drinking water source generally considered to be more 
vulnerable to frequent high concentrations of pesticides than most 
locations that could be used for crop production.
    When EPA completed the carbaryl Interim Reregistration Eligibility 
Decision (IRED)\1\ in June 2003, EPA compared the estimated drinking 
water concentrations (EDWCs) of pesticides, from the PRZM/EXAMS model, 
with a drinking water level of concern (DWLOC), a value representing 
the concentration of a pesticide in drinking water that would represent 
the upper limit in light of total aggregate exposure to that pesticide 
from food, water, and residential uses of that pesticide. The DWLOC 
approach was developed in the mid 1990s as part of EPA's review of 
pesticides under FQPA, before the current risk assessment methodologies 
became available. EPA now uses the output of daily concentration values 
from tier two modeling as an input to DEEM-FCIDTM, which 
combines water concentrations with drinking water consumption 
information in the daily diet to generate a distribution of exposures 
from consumption of drinking water containing pesticide residues. These 
results are then used to calculate a probabilistic assessment of the 
aggregate human exposure and risk from residues in food and drinking 
water.
---------------------------------------------------------------------------

    \1\ Because carbaryl is a member of the NMC group of pesticides, 
which share a common mechanism of toxicity, EPA was unable to 
complete the carbaryl Reregistration Eligibility Decision (RED) 
before completion of the NMC cumulative risk assessment in September 
2007.
---------------------------------------------------------------------------

    EPA also considers available surface water monitoring data, 
including data from the US Geological Survey (USGS) National Water 
Quality Assessment Program (NAWQA), in conducting drinking water 
assessments. For the 2007 carbaryl RED, EPA considered data from a 
variety of sources, including NAWQA, the joint USGS-EPA Mini Pilot 
Monitoring Program, Washington and California state monitoring data, 
and registrant voluntary water monitoring study measuring carbaryl in 
targeted community water systems associated with watersheds having high 
carbaryl use.
    c. Residential exposures. Generally, in assessing residential 
exposure to pesticides EPA relies on its Standard Operating Procedures 
(SOPs) for Residential Exposure Assessment and subsequent amendments 
(Refs. 6, 7, and 8). The Residential SOPs establish the approaches used 
for estimating application and post-application exposures in a 
residential setting. SOPs have been developed for many common exposure 
scenarios including pesticide treatment of lawns, garden plants, trees, 
swimming pools, pets, and indoor surfaces including crack and crevice 
treatments. The SOPs are based on existing monitoring and survey data 
including information on activity patterns, particularly for children. 
Where available, EPA relies on pesticide-specific data in estimating 
residential exposures. Although limited carbaryl specific data were 
available at the time the carbaryl IRED was completed, additional data 
were submitted in response to the 2005 Data Call-In (DCI) for carbaryl. 
These data were reviewed and incorporated into the revised residential 
risk assessment used to support the final carbaryl RED. Residential 
exposure from carbaryl was estimated using EPA's Residential SOPs (as 
amended) as well as a turf dissipation study for carbaryl which 
quantified turf transferable residues after carbaryl application to 
turf and other monitoring data available to the Agency (e.g., residue 
decline studies on garden crops).
    3. Risk characterization. The final step in the risk assessment is 
risk characterization. In this step, EPA combines information from the 
first three steps (hazard identification, level of concern/dose-
response analysis, and human exposure assessment) to

[[Page 64234]]

quantitatively estimate the risks posed by a pesticide. Separate 
characterizations of risk are conducted for different durations of 
exposure. Additionally, separate and, where appropriate, aggregate 
characterizations of risk are conducted for the different routes of 
exposure (dietary and non-dietary).
    For threshold risks, EPA estimates risk in one of two ways. Where 
EPA has calculated an RfD/PAD, risk is estimated by expressing human 
exposure as a percentage of the RfD/PAD. Exposures lower than 100 
percent of the RfD/PAD are generally not of concern. Alternatively, EPA 
may express risk by dividing the estimated human exposure into the PoD 
to derive a margin of exposure (MOE). The MOE is compared with a level 
of concern, which is the product of all applicable uncertainty/safety 
factors. In contrast to the RfD/PAD approach, the higher the MOE, the 
lower the risk concern for the pesticide. Accordingly, if the level of 
concern is 100, MOEs equal to or exceeding 100 would generally not be 
of concern.
    As a conceptual matter, the RfD/PAD and MOE approaches are 
fundamentally equivalent. For a given risk and given exposure of a 
pesticide, if exposure to a pesticide were found to be acceptable under 
an RfD/PAD analysis it would also pass under the MOE approach, and 
vice-versa. However, for any specific pesticide, risk assessments for 
different exposure durations or routes may yield different results. 
This is a function not of the choice of the RfD/PAD or MOE approach but 
of the fact that the levels of concern and the levels of exposure may 
differ depending on the duration and route of exposure.
    For non-threshold risks (generally, cancer risks), EPA uses the 
slope of the dose-response curve for a pesticide in conjunction with an 
estimation of human exposure to that pesticide to estimate the 
probability of occurrence of additional adverse effects. For non-
threshold cancer risks, EPA generally considers cancer risk to be 
negligible if the probability of increased cancer cases falls within 
the range of 1 in 1 million. Risks exceeding values within that range 
would raise a risk concern.

C. Science Policy Considerations

    1. EPA policy on the children's safety factor. As the above brief 
summary of EPA's risk assessment practice indicates, the use of safety 
factors plays a critical role in the process. This is true for 
traditional 10X safety factors to account for potential differences 
between animals and humans when relying on studies in animals (inter-
species safety factor) and potential differences among humans (intra-
species safety factor) as well as the FQPA's additional 10X children's 
safety factor.
    In general, Section 408 of FFDCA provides that EPA shall apply an 
additional tenfold margin of safety for infants and children in the 
case of threshold effects to account for prenatal and postnatal 
toxicity and the completeness of the data base on toxicity and exposure 
unless EPA determines that a different margin of safety will be safe 
for infants and children. Margins of safety are incorporated into EPA 
assessments either directly through use of a margin of exposure 
analysis or through using uncertainty (safety) factors in calculating a 
dose level that poses acceptable risk to humans.
    In applying the children's safety factor provision, EPA has 
interpreted the statutory language as imposing a presumption in favor 
of applying an additional 10X safety factor (Ref. 9). Thus, EPA 
generally refers to the additional 10X factor as a presumptive or 
default 10X factor. EPA has also made clear, however, that the 
presumption can be overcome if reliable data demonstrate that a 
different factor is safe for children (Id.). In determining whether a 
different factor is safe for children, EPA focuses on the three factors 
listed in section 408(b)(2)(C) - the completeness of the toxicity 
database, the completeness of the exposure database, and potential pre- 
and post-natal toxicity. In examining these factors, EPA strives to 
make sure that its choice of a safety factor, based on a weight-of-the-
evidence evaluation, does not understate the risk to children. (Id.).
    When EPA evaluated the carbaryl toxicological database in 2003 to 
determine the appropriate FQPA Safety Factor for use in the IRED, 
available studies included rat and rabbit teratology (developmental 
toxicity) studies, a rat developmental neurotoxicity study, a rat 
reproductive toxicity study, a 4-week dermal rat study, acute and 
subchronic neurotoxicity screening studies, and a chronic oral dog 
study (Ref. 10). Based on the weight of the evidence as evaluated in 
2003, the FQPA Safety Factor was determined to be 3X due to the lack of 
a NOAEL in the chronic dog study. This was what the weight of the 
evidence showed in 2003.
    The science has advanced since 2003; additional information on 
pharmacokinetics as well as additional acute cholinesterase data have 
become available for carbaryl and other NMCs. Due to the rapid recovery 
of cholinesterase activity, chronic exposure is no longer considered to 
be a concern for carbaryl. As the science has advanced, science policy 
has also evolved. As EPA acquired developmental neurotoxicity and 
comparative cholinesterase data on the NMCs, it became apparent that 
comparative cholinesterase studies measuring red blood cell (RBC) and 
brain cholinesterase inhibition in both maternal and young animals 
(postnatal day 11 (PND11) and postnatal day 17 (PND17)) were a more 
accurate predictor of age-related sensitivity than developmental 
neurotoxicity studies measuring behavioral and histopathological 
changes. Therefore, EPA informed registrants that, in the absence of 
comparative cholinesterase data for each pesticide, a 10X FQPA Safety 
Factor would be applied to that pesticide in the NMC cumulative risk 
assessment. If comparative cholinesterase data were available, EPA used 
a data derived approach for the FQPA Safety Factor by comparing the 
benchmark dose (BMD) at the 10% inhibition level for either brain or 
RBC acetyl cholinesterase inhibition between maternal animals and the 
juvenile animals (typically PND11).
    2. EPA Policy on cholinesterase inhibition as a regulatory 
endpoint. Cholinesterase inhibition is a disruption of the normal 
process in the body by which the nervous system chemically communicates 
with muscles and glands. Communication between nerve cells and a target 
cell (i.e., another nerve cell, a muscle fiber, or a gland) is 
facilitated by the chemical, acetylcholine. When a nerve cell is 
stimulated it releases acetylcholine into the synapse (or space) 
between the nerve cell and the target cell. The released acetylcholine 
binds to receptors in the target cell, stimulating the target cell in 
turn. As EPA has explained, ``the end result of the stimulation of 
cholinergic pathway(s) includes, for example, the contraction of smooth 
(e.g., in the gastrointestinal tract) or skeletal muscle, changes in 
heart rate or glandular secretion (e.g., sweat glands) or communication 
between nerve cells in the brain or in the autonomic ganglia of the 
peripheral nervous system.'' (Ref. 11 at 10).
    Acetylcholinesterase (AChE) is an enzyme that breaks down 
acetylcholine and terminates its stimulating action in the synapse 
between nerve cells and target cells. When AChE is inhibited, 
acetylcholine builds up prolonging the stimulation of the target cell. 
This excessive stimulation potentially results in a broad range of 
adverse effects on many bodily functions. Depending on

[[Page 64235]]

the degree of inhibition these effects can be serious, even fatal.
    EPA's cholinesterase inhibition policy statement explains EPA's 
approach to evaluating the risks posed by cholinesterase-inhibiting 
pesticides such as carbaryl. (Id). The policy focuses on three types of 
effects associated with cholinesterase-inhibiting pesticides that may 
be assessed in animal and human toxicological studies: (1) 
physiological and behavioral/functional effects; (2) cholinesterase 
inhibition in the central and peripheral nervous system; and (3) 
cholinesterase inhibition in red blood cells and blood plasma. The 
policy discusses how such data should be integrated in deriving an 
acceptable dose (RfD/PAD) for a cholinesterase-inhibiting pesticide.
    Clinical signs or symptoms of cholinesterase inhibition in humans, 
the policy concludes, provide the most direct evidence of the adverse 
consequences of exposure to cholinesterase-inhibiting pesticides. 
Nonetheless, as the policy notes, due to strict ethical limitations, 
studies in humans are ``quite limited.'' (Id. at 19). Although animal 
studies can also provide direct evidence of cholinesterase inhibition 
effects, animal studies cannot easily measure cognitive effects of 
cholinesterase inhibition such as effects on perception, learning, and 
memory. For these reasons, the policy recommends that ``functional data 
obtained from human and animal studies should not be relied on solely, 
to the exclusion of other kinds of pertinent information, when weighing 
the evidence for selection of the critical effect(s) that will be used 
as the basis of the RfD or RfC.'' (Id. at 20).
    After clinical signs or symptoms, cholinesterase inhibition in the 
nervous system provides the next most important endpoint for evaluating 
cholinesterase-inhibiting pesticides. Although cholinesterase 
inhibition in the nervous system is not itself regarded as a direct 
adverse effect, it is ``generally accepted as a key component of the 
mechanism of toxicity leading to adverse cholinergic effects.'' (Id. at 
25). As such, the policy states that it should be treated as ``direct 
evidence of potential adverse effects'' and ``data showing this 
response provide valuable information in assessing potential hazards 
posed by anticholinesterase pesticides.'' (Id.). AChE inhibition in 
brain and the peripheral nervous system is the initial adverse 
biological event which results from exposure to NMC pesticides, such as 
carbaryl, and with sufficient levels of inhibition leads to other 
effects. Thus, AChE inhibition provides the most appropriate effect to 
use in risk extrapolation for derivation of RfDs and PADs. Protecting 
against AChE inhibition ensures that the other adverse effects 
mentioned above do not occur.
    In summary, EPA uses a weight of evidence approach to determine the 
toxic effect that will serve as the appropriate PoD for a risk 
assessment for AChE inhibiting pesticides, such as carbaryl (Id). The 
neurotoxicity that is associated with these pesticides can occur in 
both the central (brain) and the peripheral nervous system. In its 
weight of the evidence analysis, EPA reviews data, such as AChE 
inhibition data from the brain, peripheral tissues and blood (e.g., RBC 
or plasma), in addition to data on clinical signs and other functional 
effects related to AChE inhibition. Based on these data, EPA selects 
the most appropriate effect on which to regulate; such effects can 
include clinical signs of AChE inhibition, central or peripheral 
nervous tissue measurements of AChE inhibition or RBC AChE measures 
(Id). Although RBC AChE inhibition is not adverse in itself, it is a 
surrogate for inhibition in peripheral tissues when peripheral data are 
not available. As such, RBC AChE inhibition provides an indirect 
indication of adverse effects on the nervous system (Id.). Due to 
technical difficulties regarding dissection of peripheral nerves and 
the rapid nature of carbaryl toxicity, measures of AChE inhibition in 
the peripheral nervous system are very rare for NMC pesticides. For 
these reasons, other state and national agencies such as California, 
Washington, Canada, the European Union, as well as the World Health 
Organization (WHO), all use blood measures in human health risk 
assessment and/or worker safety monitoring programs.
    3. Benchmark dose. EPA has relied on a benchmark dose approach for 
deriving the PoD from the available rat toxicity studies (Ref. 12). A 
benchmark dose, or BMD, is a point estimate along a dose-response curve 
that corresponds to a specific response level. For example, a 
BMD10 represents a 10% change from the background or typical 
value for the response of concern. Generically, the direction of change 
from background can be an increase or a decrease depending on the 
biological parameter and the chemical of interest. In the case of 
carbaryl, inhibition of AChE is the toxic effect of concern. Following 
exposure to carbaryl, the normal biological activity of the AChE enzyme 
is decreased (i.e., the enzyme is inhibited). Thus, when evaluating 
BMDs for carbaryl, the Agency is interested in a decrease in AChE 
activity compared to normal activity levels, which are also termed 
``background'' levels. Measurements of ``background'' AChE activity 
levels are usually obtained from animals in experimental studies that 
are not treated with the pesticide of interest (i.e., ``negative 
control'' animals).
    In addition to the BMD, a ``confidence limit'' was also calculated. 
Confidence limits express the uncertainty in a BMD that may be due to 
sampling and/or experimental error. The lower confidence limit on the 
dose used as the BMD is termed the BMDL, which the Agency uses as the 
PoD. Use of the BMDL for deriving the PoD rewards better experimental 
design and procedures that provide more precise estimates of the BMD, 
resulting in tighter confidence intervals. Use of the BMDL also helps 
ensure with high confidence (e.g., 95% confidence) that the selected 
percentage of AChE inhibition is not exceeded. From the PoD, EPA 
calculates the RfD and aPAD.
    Numerous scientific peer review panels over the last decade have 
supported the Agency's application of the BMD approach as a 
scientifically supportable method for deriving PoDs in human health 
risk assessment, and as an improvement over the historically applied 
approach of using NOAELs or LOAELs. The NOAEL/LOAEL approach does not 
account for the variability and uncertainty in the experimental 
results, which are due to characteristics of the study design, such as 
dose selection, dose spacing, and sample size. With the BMD approach, 
all the dose response data are used to derive a PoD. Moreover, the 
response level used for setting regulatory limits can vary based on the 
chemical and/or type of toxic effect (Refs. 12, 13, 14, and 15). 
Specific to carbaryl and other NMCs, the FIFRA SAP has reviewed and 
supported the statistical methods used by the Agency to derive BMDs and 
BMDLs on two occasions, February 2005 and August 2005 (Refs. 14 and 
15).

IV. Carbaryl Tolerances

A. Regulatory Background

    Carbaryl is a carbamate insecticide and molluscide that was first 
registered in 1959 for use on cotton. Carbaryl has many trade names, 
but is most commonly known as Sevin[reg]. In 1980, the Agency published 
a position document summarizing its conclusions from a Special Review 
of carbaryl, and concluded that risk concerns, particularly those 
related to teratogenicity, did not warrant cancellation of the 
registration for carbaryl. A Registration Standard, issued for carbaryl 
in 1984 and revised

[[Page 64236]]

in 1988, described the terms and conditions for continued registration 
of carbaryl. At the time carbaryl was assessed for purposes of 
reregistration, carbaryl was registered for use on over 400 
agricultural and non-agricultural use sites, and there were more than 
140 tolerances for carbaryl in the Code of Federal Regulations (40 CFR 
180.169). For example, carbaryl was registered for domestic outdoor 
uses on lawns and gardens, and indoors in kennels and on pet sleeping 
quarters. It was also registered for direct application to cats and 
dogs (collar, powder, and dip) to control fleas and ticks.
    EPA completed an IRED for carbaryl on June 30, 2003 (2003 IRED). 
The Agency amended the IRED on October 22, 2004 (2004 Amended IRED), 
and published a formal Notice of Availability for the document, which 
provided for a 60-day public comment period (Ref. 16). EPA received 
numerous comments on the carbaryl IRED, including the NRDC petition 
requesting that EPA cancel all carbaryl registrations and revoke all 
tolerances. The Agency published a Notice of Receipt for the petition 
in the Federal Register, which provided a public comment period. 
Petition to Revoke or Modify Tolerances Established for Carbaryl; 
Notice of Availability, 70 FR 16281 (March 30, 2005). The mitigation 
detailed in the 2004 Amended IRED for residential uses included: 
canceling liquid broadcast applications to home lawns pending EPA 
review of pharmacokinetic data to refine post-application risk 
estimates; home garden/ornamental dust products must be packaged in 
ready-to-use shaker can containers, with no more than 0.05 lbs. active 
ingredient per container; cancellation of the following uses and 
application methods: all pet uses (dusts and liquids) except collars, 
aerosol products for various uses, belly grinder applications of 
granular and bait products for lawns, hand applications of granular and 
bait products for ornamentals and gardens.
    On March 9, 2005, EPA issued a cancellation order for the liquid 
broadcast use of carbaryl on residential turf to address post-
application risk to toddlers (Ref. 17). In March 2005, EPA also issued 
generic and product-specific DCIs for carbaryl. The carbaryl generic 
DCI required several studies of the active ingredient carbaryl, 
including additional toxicology, worker exposure monitoring, and 
environmental fate data. The product-specific DCI required acute 
toxicity and product chemistry data for all pesticide products 
containing carbaryl; these data are being used for product labeling. 
EPA has received numerous studies in response to these DCIs, and, where 
appropriate, these studies were considered in the tolerance 
reassessment.
    In response to the DCIs, many carbaryl registrants chose to 
voluntarily cancel their carbaryl products, rather than revise their 
labels or conduct studies to support these products. EPA published a 
notice of receipt of this request in the Federal Register on October 
28, 2005 (70 FR 62112), followed by a cancellation order issued on July 
3, 2006. One technical registrant, Burlington Scientific, chose to 
cancel their technical product, leaving Bayer CropScience (Bayer) as 
the sole technical registrant for carbaryl. Approximately two-thirds of 
all of the carbaryl products registered at the time of the 2003 IRED 
have been canceled through this process.
    In addition, Bayer, the sole remaining technical registrant 
responsible for developing data, requested waivers of required exposure 
monitoring or residue studies because these use scenarios are not on 
any Bayer technical or product labels or were to be deleted from Bayer 
labels: carbaryl use in or on pea and bean, succulent shelled (subgroup 
6B); millet; wheat; pre-plant root dip for sweet potato; pre-plant root 
dip/drench fpr nursery stocks, vegetable transplants, bedding plants, 
and foliage plants; use of granular formulations on leafy vegetables 
(except Brassica); ultra low volume (ULV) application for adult 
mosquito control; and dust applications in agriculture.
    Bayer subsequently requested that all of their carbaryl 
registrations bearing any of these uses be amended to delete these 
uses; EPA published a Notice of receipt of this request in the Federal 
Register on August 20, 2008 (73 FR 49184), and plans to approve Bayer's 
request and issue a final order amending these registrations at the end 
of the comment period for the Notice. As a consequence, EPA has 
notified all affected registrants that these uses and application 
methods must be deleted from their carbaryl product labels. EPA has 
identified thirty four (34) product labels from 14 registrants (other 
than Bayer) bearing these end uses. All of these registrants have 
requested that their affected carbaryl product registrations be amended 
to delete these uses. EPA published a Notice of receipt of these 
requests in the Federal Register on August 20, 2008 and will publish a 
second Notice of Receipt of these requests on or about October 8, 2008.
    In June 2006, EPA determined that the uses associated with 120 of 
the existing carbaryl tolerances are not significant contributors to 
the overall NMC cumulative risk and as a result these tolerances will 
have no effect on the retention or revocation of other NMC tolerances. 
Therefore, EPA considered these 120 tolerances for carbaryl as 
reassessed on June 29, 2006, and posted this decision on the internet 
site. (See https://www.epa.gov/pesticides/cumulative/carbamates_
commodity.pdf).
    Carbaryl is a member of the NMC class of pesticides which share a 
common mechanism of toxicity by affecting the nervous system via 
cholinesterase inhibition. Specifically, carbaryl is a reversible 
inhibitor of AChE. A cumulative risk assessment, which evaluates 
exposures based on a common mechanism of toxicity, was conducted to 
evaluate risk from food, drinking water, residential use, and other 
non-occupational exposures resulting from registered uses of NMC 
pesticides, including carbaryl.
    In late November 2006, EPA received data from a carbaryl 
comparative cholinesterase study, conducted to determine the 
comparative sensitivity of adults and offspring to cholinesterase 
inhibition by carbaryl. These data were used to revise the FQPA Safety 
Factor for carbaryl for the NMC cumulative risk assessment and to 
select new toxicology endpoints (PoDs) for the risk assessment. The 
Agency determined that it was appropriate to use the new FQPA Safety 
Factor and revised PoDs in both the NMC cumulative risk assessment and 
the carbaryl-specific human health risk assessment. Because this 
necessitated a revision of the carbaryl human health aggregate risk 
assessment, EPA also considered additional new data generated in 
response to the DCI, new methodologies, and other new information in 
performing its most recent assessment of carbaryl and in responding to 
this Petition. EPA has thus, in effect, revised the carbaryl single 
chemical assessment in response to the issues raised during the public 
comment process as well as based upon more recent data and analytical 
methods.
    On September 26, 2007, EPA issued the NMC cumulative risk 
assessment. EPA concluded that the cumulative risks associated with the 
NMC pesticides meet the safety standard set forth in section 408(b)(2) 
of the FFDCA, provided that the mitigation specified in the NMC 
cumulative risk assessment is implemented, such as cancellation of all 
uses of carbofuran, termination of methomyl use on grapes, etc. EPA has 
therefore terminated the tolerance reassessment process under 408(q) of

[[Page 64237]]

the FFDCA. (See Ref. 18 for additional information).
    In conjunction with the NMC cumulative risk assessment, EPA 
completed a RED for carbaryl on September 24, 2007 and issued this RED 
on October 17, 2007 with a formal Notice of Availability in the Federal 
Register (72 FR 58844). In addition to relying on the NMC cumulative 
risk assessment to determine that the cumulative effects from exposure 
to all NMC residues, including carbaryl, was safe, the carbaryl RED 
relied upon the revised assessments and the mitigation that had already 
been implemented (e.g., cancellation of pet uses except for collars). 
In addition, the RED included additional mitigation with respect to 
granular turf products for residential use; namely, that product labels 
direct users to water the product in immediately after application. 
Subsequently, on August 25, 2008, EPA completed an addendum to the 
Carbaryl RED incorporating the results of a revised occupational risk 
assessment and modified mitigation measures for the protection of 
workers. Elsewhere in this issue of the Federal Register EPA is 
announcing the availability of the amendments to the Carbaryl RED.

B. FFDCA Tolerance Reassessment and FIFRA Pesticide Reregistration

    As required by the Food Quality Protection Act of 1996, EPA 
reassessed the safety of the carbaryl tolerances under the safety 
standard established in the FQPA. In the September 2007 RED for 
carbaryl, EPA evaluated the human health risks associated with all 
currently registered uses of carbaryl and determined that there is a 
reasonable certainty that no harm will result from aggregate non-
occupational exposure to the pesticide chemical residue. In making this 
determination, EPA considered dietary exposure from food and drinking 
water and all other non-occupational sources of pesticide exposure for 
which there is reliable information (Ref. 18). The Agency has concluded 
that with the adoption of the risk mitigation measures identified in 
the NMC cumulative risk assessment, all of the tolerances for carbaryl 
meet the safety standard as set forth in section 408(b)(2)(D) of the 
FFDCA. Therefore, the tolerances established for residues of carbaryl 
in/on raw agricultural commodities were considered reassessed as safe 
under section 408(q) of FFDCA, as amended by FQPA, in September 2007. 
These findings satisfied EPA's obligation to review the carbaryl 
tolerances under the FQPA safety standard.
    To implement the carbaryl tolerance reassessment, EPA commenced 
with rulemaking in 2008. The Agency published a Notice of proposed 
tolerance actions in the May 21, 2008 Federal Register (73 FR 29456). 
This proposed rule provided for a 60 day public comment period. No 
comments relevant to carbaryl tolerances were received and EPA 
published a Notice of final tolerance actions in the September 10, 2008 
Federal Register (73 FR 52607). This rule codifies the carbaryl 
tolerances in 40 CFR 180.169.

V. The Petition to Revoke Tolerances

    NRDC filed a petition dated January 10, 2005 (Petition), 
requesting, among other things, that EPA cancel all carbaryl 
registrations and revoke all carbaryl tolerances (Ref. 1). In response 
to EPA's publication of the Petition pursuant to section 408(d) of the 
FFDCA, NRDC resubmitted its Petition and earlier comments in support of 
its Petition. (See Docket ID EPA-HQ-OPP-2005-0077-0066).
    It should be noted that NRDC's January 10, 2005 submission is in 
the form of comments on and requests for changes to the Carbaryl 
Interim Reregistration Eligibility Decision published in the Federal 
Register on October 27, 2004, 70 FR 62663; (Ref. 16). Nonetheless, in 
the introduction to the comments, NRDC included a st