United States Prevention, Pesticides EPA-738R07-018
Environmental Protection and Toxic Substances September 2007
i|P Agency (7508P)
Reregistration
Eligibility Decision
(RED) for Carbaryl
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REREGISTRATION ELIGIBILITY
DECISION
for
Carbaryl
Case No. 0080
Approved by:
Steven Bradbury, Ph.D.
Director, Special Review and
Reregistration Division
Date '
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Carbaryl Reregistration Eligibility Decision Team
Office of Pesticide Programs
Biological and Economic Analysis Assessment
Donald Atwood
Timothy Kiely
Environmental Fate and Effects Risk Assessment
Betsy Behl
Dirk Young
R. David Jones
Health Effects Risk Assessment
Felecia Fort
Kit Farwell
Mike Metzger
Steve Nako
Wade Britton
Registration Support
John Hebert
Venus Eagle
Risk Management
Christina Scheltema
Neil Anderson
Office of General Counsel
Andrew Simons
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Carbaryl Reregistration Eligibility Decision Team
Office of Pesticide Programs
Biological and Economic Analysis Assessment
Donald Atwood
Timothy Kiely
Environmental Fate and Effects Risk Assessment
Betsy Behl
Dirk Young
R. David Jones
Health Effects Risk Assessment
Wade Britton
Felecia Fort
Kit Farwell
Mike Metzger
Steve Nako
Elissa Reaves
Registration Support
John Hebert
Venus Eagle
Risk Management
Christina Scheltema
Neil Anderson
Office of General Counsel
Andrew Simons
IV
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I. Introduction
The Environmental Protection Agency (EPA or the Agency) has completed the
reregi strati on eligibility decision (RED) for the currently registered uses of the N-methyl
carbamate pesticide carbaryl. This document presents EPA's revised carbaryl human
health risk assessment under the Food Quality Protection Act (FQPA) and the Agency's
final tolerance reassessment decision for carbaryl. This RED amends the Interim
Reregi strati on Eligibility Decision (IRED) for carbaryl, which was completed by EPA on
June 30, 2003 and previously amended on October 22, 2004, and completes the
reregi strati on process for carbaryl. The Agency is currently revisiting the revised
occupational risk assessment, which does not identify any additional risk concerns, and
will amend this RED to incorporate any resulting changes in the regulatory decision. In
addition, as a separate action, EPA is preparing a response to petitions to cancel all uses
of carbaryl and revoke all carbaryl tolerances. The Agency's response to these petitions
will be released at a later date.
Carbaryl belongs to the N-methyl carbamate group of pesticides, which share a
common mechanism of toxicity. The FQPA requires EPA to consider cumulative risk for
pesticides that share a common mechanism of action before completing tolerance
reassessment for individual chemicals in the common mechanism group, hence the
interim decision. The carbaryl tolerance reassessment is now complete with the
cumulative risk assessment for the N-methyl carbamate group of pesticides so that all of
the remaining carbaryl tolerances, not previously reassessed, can be considered
reassessed in accordance with the FQPA.
A. Regulatory History
EPA completed an IRED for carbaryl on June 30, 2003, in accordance with a
Consent Decree with the Natural Resources Defense Council (NRDC). The completed
IRED was posted on the EPA internet for public viewing in early July 2003. The Agency
amended the IRED on October 22, 2004, and published a formal Notice of Availability
for the document, which provided for a 60-day public comment period. EPA received
numerous comments on the carbaryl IRED, including two petitions. Both the NRDC and
the Washington Toxics Coalition submitted petitions requesting that EPA cancel all uses
of carbaryl and revoke all tolerances. The Agency published a Notice of Receipt for each
of these petitions in the Federal Register, which provided for a public comment period on
the petitions (see FR of March 30, 2005 and October 13, 2006). The Agency is currently
preparing a response to public comments, including these petitions. The response to
comments will be released at a later date.
On March 10, 2005, EPA issued a cancellation order for the liquid broadcast use
of carbaryl on residential turf to address post-application risk to toddlers. EPA took this
action because pharmacokinetic data developed by the carbaryl registrant, Bayer
CropScience, were not sufficient to address the risk concerns for toddlers identified in the
IRED. The FIFRA Science Advisory Panel (SAP) reviewed these data in December
2004 and concluded that the data were not sufficient to address the risk concern for
toddlers.
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In March 2005, EPA also issued generic and product-specific data call-ins (DCIs)
for carbaryl. The carbaryl generic DCI required several studies for the active ingredient
carbaryl, including additional toxicology, worker exposure monitoring, and environ-
mental fate data. The product DCI required acute toxicity and product chemistry data for
all pesticide products containing carbaryl; these data will be used for product labeling.
EPA has received numerous studies in response to these DCIs, and, where appropriate,
these studies have been considered in the revised risk assessment for this 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. One technical registrant, Burlington Scientific, chose to cancel their technical
product, leaving Bayer CropScience as the sole technical registrant for carbaryl.
Approximately two-thirds of all of the carbaryl products registered at the time of the
carbaryl IRED (June 2003) have been canceled through this process.
In June 2006, EPA determined that the uses associated with 120 of the existing
carbaryl tolerances are not significant contributors to the overall N-methyl carbamate
cumulative risk and as a result these tolerances will have no effect on the retention or
revocation of other N-methyl carbamate tolerances. Therefore, EPA considered these
120 tolerances for carbaryl as reassessed on June 29, 2006, and posted this decision on
the internet site, http://www.epa.gov/pesticides/cumulative/carbamates_commodity.pdf
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 N-methyl carbamate cumulative risk assessment.
The Agency determined that it was appropriate to use this new FQPA safely factor in
both the N-methyl carbamate cumulative risk assessment and the carbaryl-specific human
health risk assessment. Because incorporating a revised FQPA safety factor would result
in a revision of the carbaryl human health aggregate risk assessment, EPA decided to also
incorporate new data generated in response to the DCI, new methodologies, and other
new information to bring the carbaryl-specific risk assessment up to date.
B. N-Methyl Carbamate Cumulative Risk Assessment
FFDCA Section 408(b)(2)(D)(v) requires that the Agency consider "available
information" concerning cumulative effects of a particular pesticides residues and "other
substances that have a common mechanism of toxicity" when considering whether to
establish, modify, or revoke a tolerance for pesticide residues in food. EPA considers
cumulative effects from pesticides and other substances because low-level exposures to
multiple chemical substances causing a common effect by a common mechanism could
lead to the same adverse health effect as would a higher level of exposure to each
individual substance.
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Carbaryl is a member of the N-methyl carbamate class of pesticides, which share
a common mechanism of toxicity by affecting the nervous system via cholinesterase
inhibition. 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 N-
methyl carbamate pesticides, including carbaryl. EPA has concluded that the cumulative
risks associated with the N-methyl carbamate pesticides meet the safety standard set forth
in section 408(b)(2) of the FFDCA. EPA is thereby terminating the tolerance
reassessment process under 408(q) of the FFDCA. For additional information, refer to
the document, Revised N-methyl Carbamate Cumulative Risk Assessment, which is
available in the EPA docket EPA-HQ-OPP-2007-0935 and on the website,
http://www.epa.gov/pesticides/cumulative/.
II Revised Human Health Risk Assessment for Carbaryl
A. What's New
The carbaryl human health risk assessment has been revised to incorporate new
data, new methodologies, updated use information, and recent residue data, and other
new information obtained from public comments to the IRED.
1. New Data
EPA issued a generic data call-in (DCI) for carbaryl in March 2005. This DCI
required several confirmatory studies, including exposure monitoring and toxicology
studies. Key studies that were incorporated into the revised human health risk assessment
include the following:
Environmental Fate
Aerobic Aquatic Metabolism. This study measures how quickly carbaryl degrades
in an aerobic aquatic environment. The half-life value from this study was used
in the drinking water modeling for carbaryl.
Drinking Water
EPA has conducted a comprehensive review of recent surface water monitoring
data for carbaryl and investigated the high carbaryl detection in groundwater
monitoring reported in the 2003 IRED.
Residential Exposure Monitoring Studies
Turf transferable residue study and addendum. This study measures the amount
of carbaryl residues from a granular product applied to turf that are available for
post-application exposure. The data from this study were used to calculate post-
application exposure and risk in the carbaryl residential risk assessment.
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Toxicology Studies
Dermal penetration study for carbaryl. Bayer CropScience conducted an in vitro
comparative dermal penetration study using rat skin and human skin. These study
data were used to determine the relative dermal absorption for carbaryl in rats and
humans. The data were used to adjust the dermal point of departure used in the
carbaryl risk assessment.
Comparative cholinesterase study. EPA's Office of Research and Development
conducted a comparative cholinesterase study to compare carbaryl-induced
cholinesterase inhibition in adult and juvenile rats. These data were used to
calculate a revised FQPA safety factor for carbaryl and to derive the toxicology
points of departure for risk assessment.
2. New Methodologies
Benchmark Dose Modeling
EPA has developed a benchmark dose analysis for carbaryl using the same
modeling methodology used in the N-methyl carbamate cumulative risk
assessment. A benchmark dose analysis models the dose-response relationship
with a dose-response curve, which allows selection of doses corresponding to a
specified level of response, called a benchmark response. This analysis allows
EPA to determine a more appropriate point of departure from a toxicology study
rather than using the study No Observable Adverse Effect Level (NOAEL) or
Lowest Observable Adverse Effect Level (LOAEL). For more information on
benchmark dose modeling, please see the EPA draft report, Benchmark Dose
Technical Guidance Document (USEPA 2000).
3. Other New Information
The mitigation measures required in the carbaryl IRED were incorporated into the
revised risk assessment, resulting in significant changes to the residential risk assessment.
EPA also incorporated the most recent available US Department of Agriculture (USDA)
Pesticide Data Program (PDF) residue data (sampling years 2003-2006) and the most
recent available data on percent of food crops treated with carbaryl into the dietary risk
assessment for food. The drinking water exposure assessment was revised to incorporate
information on percent cropped area in various regions of the country and recent surface
water monitoring data. EPA also incorporated new information provided in the public
comments on the IRED into the revised risk assessment.
Updated Use Information
As part of EPA's re-evaluation of carbaryl, the Agency reviewed all currently available
information on use and usage of this pesticide. A summary of the readily available use
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data for agricultural crops is given in Table 1. The Agency used the percent crop treated
data from this table in the revised dietary risk assessment for carbaryl. For the few
commodities where percent crop treated was not calculated due to insufficient data, EPA
used the percent crop treated values from the 2002 Quantitative Use Analysis for
Carbaryl.
Table 1. Summary of Carbaryl Use Data for Agricultural Crops
Crop
Alfalfa
Almonds *
Apples
Asparagus
Avocados
Beans, Green
Beetsf
Blackberries
Blueberries
Broccoli
Brussels Sprouts *
Cabbage
Canola/Rapeseed
Cantaloupes
Carrots
Cauliflower
Celery
Cherries
Collards
Corn
Cotton
Cranberries f
Cucumbers
Dry Beans/Peas
Eggplant
Grapefruit
Grapes
Greens, Mustard
Greens, Turnip
Honey dew
Kale
Lemons
Lettuce
Nectarines *
Okra
Olives *
Onions
Oranges
Parsley f
Peaches
Peanuts
Pears
Pounds Active Ingredient (a.i.)
used per year
50,000
4,000
2,000
60,000
2,000
10,000
<500
3,000
20,000
4,000
<500
2,000
<500
10,000
4,000
<500
1,000
70,000
2,000
20,000
5,000
30,000
20,000
2,000
<500
40,000
80,000
1,000
3,000
2,000
<5000
4,000
6,000
4,000
6,000
7,000
<500
100,000
<500
60,000
20,000
3,000
Percent Crop Treated
Average
<1
<1
5
35
<1
5
5
30
20
<1
Not Calculated
<1
<1
15
5
<1
<1
15
5
<1
<1
20
5
<1
5
10
5
5
20
35
5
<1
<1
5
30
<1
<1
5
5
10
<1
<1
Maximum
<2.5
<2.5
15
45
5
5
Not Calculated}
35
25
5
Not Calculated
5
25
5
<2.5
<2.5
25
5
<2.5
<2.5
Not Calculated
10
<2.5
5
20
5
5
20
35
5
<2.5
<2.5
5
30
<2.5
<2.5
5
Not Calculated
20
5
5
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Crop
Peas, Green
Pecans
Peppers
Pistachios *
Potatoes
Prunes & Plums *
Pumpkins
Rice
Sodt
Sorghum
Soybeans
Spinach
Squash
Strawberries
Sugar Beets
Sunflowers
Sweet Corn
Sweet Potatoesf
Tangelos
Tangerines
Tobacco
Tomatoes
Walnuts
Watermelons
Wheat
Pounds Active Ingredient (a.i.)
used per year
<500
200,000
9,000
10,000
20,000
5,000
20,000
30,000
2,000
10,000
30,000
<500
10,000
20,000
4,000
6,000
20,000
20,000
1,000
9,000
2,000
20,000
2,000
20,000
20,000
Percent Crop Treated
Average
<1
10
5
5
<1
<1
15
<1
<1
<1
<1
<1
15
15
<1
<1
<1
15
5
5
<1
5
<1
10
<1
Maximum
<2.5
15
5
5
5
5
25
<2.5
Not Calculated
<2.5
<2.5
<2.5
20
25
<2.5
<2.5
5
Not Calculated
5
10
<2.5
10
<2.5
15
<2.5
*The only use data available for this crop is from California's Department of Pesticide Regulation, but 95%
or more of the U.S. acreage for this crop is in California, f Data from Crop Life America, National
Pesticide Use Database 2002, because no other data are available. { Not calculated due to insufficient data.
EPA also evaluated nonagricultural use of carbaryl, including golf courses, lawn
care operators, horticultural nurseries and greenhouses, commercial turf, sod farms,
landscape contractors, flea control, fire ant control, and homeowner outdoor use. The
Agency obtained information about these uses from proprietary sources. A summary of
nonagri cultural use data for carbaryl from 1999 to 2005 is given in Table 2.
Table 2. Summary of Carbaryl Nonagricultural Use Data.
Use Category
Turf
Landscape and Horticulture
Uses in Category
Turf farms
Commercial turf
Golf courses
Lawn Care Operators
Nurseries
Greenhouses
Annual Average Pounds
Applied
(active ingredient)
201,000
44,000
Because carbaryl is also used extensively by homeowners, primarily for lawn
care, EPA has reviewed the available data on carbaryl use/usage on residential lawns as
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well as potential alternative pesticides. Details of this review may be found in the July
13, 2007, document, Alternative Assessment for Carbaryl Use on Residential Lawns.
4. Revised Toxicology Endpoints
New Toxicology Data
Comparative Cholinesterase Study. This study was conducted to determine
whether young animals are more susceptible to the effects of carbaryl than adults. This
study showed that juvenile 11-day-old (post natal day 11, or PND11) pups were more
sensitive to inhibition of brain cholinesterase from carbaryl than adult rats. The results of
this study were used to revise the FQPA safety factor for carbaryl. EPA also used this
study to determine the point of departure for calculating risks to infants and children.
EPA conducted a benchmark dose analysis for the carbaryl comparative
cholinesterase study, using the same modeling methodology used in the N-methyl
carbamate cumulative risk assessment. The Agency estimated the 10% benchmark dose
response (BMD10) and the BMDLio, or lower 95% confidence limit of the benchmark
dose, for this study. The Agency also conducted a full benchmark dose analysis of all rat
oral toxicity studies for adults; this analysis showed that the BMDLio for pups is also
protective for adults. Because the brain is the target tissue for the N-methyl carbamates,
and the brain BMDLio of 1.1 mg/kg is also protective of cholinesterase inhibition in
blood, then the brain BMDLio is the appropriate point of departure for both children and
adults in the revised carbaryl risk assessment. For additional details regarding the
comparative cholinesterase study, see the May 7, 2007 document, Report on Comparative
Cholinesterase Study of Carbaryl and the June 29, 2007 document, Carbaryl: Updated
Endpoint Selection for Single Chemical Risk Assessment.
Dermal Penetration Study. An in vitro dermal penetration study was conducted
using both rat and human skin (MRID 47151902). This study showed that rat skin was
2.8 times more permeable to carbaryl than human skin. Therefore, the dermal point of
departure was changed from 49 to 86 mg/kg/day. Additional information about this study
may be found in the June 28, 2007 document, Carbaryl: Review of in vitro Dermal
Absorption Study.
FQPA Safety Factor
To complete the carbaryl IRED in 2003, EPA evaluated the potential for special
sensitivity of infants and children to carbaryl and the need for an additional FQPA safety
factor. After evaluating the entire toxicity database available for carbaryl at that time, the
FQPA safety factor, to account for special susceptibility of infants and children, was
reduced from lOx to Ix for all scenarios, except for the chronic dietary endpoint where a
3x uncertainty factor was used to account for the lack of a NOAEL. This decision and
rationale is described in detail in the technical support documents for the carbaryl IRED.
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The comparative cholinesterase study data was used to derive a new FQPA
safety factor by comparing the BMDio for brain cholinesterase inhibition between adults
and pups at postnatal day 11. Because these pups were 1.8x more sensitive to brain
cholinesterase inhibition than the adults, the FQPA safety factor was revised to 1.8x, and
applied to both the N-methyl carbamate cumulative and the carbaryl-specific risk
assessments. This safety factor is applied to the dermal endpoint because the endpoint
was selected from a dermal toxicity study, because there are no comparative
cholinesterase data in offspring from dermal exposure, and because juvenile rats are 1.8x
more sensitive than adults based on the oral comparative cholinesterase study in rats.
However, the FQPA safety factor is reduced to Ix for oral and inhalation endpoints
because these endpoints are selected from the comparative cholinesterase data for the
most sensitive population (postnatal day 11 pups).
Revised Toxicology Endpoints for Carbaryl Risk Assessment
As a result of the new toxicology and dermal penetration data for carbaryl, as well
as the incorporation of the benchmark dose methodology into EPA's toxicology
assessments, the Agency revisited the toxicology endpoints or points of departure for the
carbaryl risk assessment. For a comparison of the toxicology endpoints used in the 2003
risk assessment with those used in this revised risk assessment, see Table 3.
The previous carbaryl risk assessment used endpoints from plasma, red blood cell,
and brain cholinesterase inhibition and related effects (tremors, abnormal gait, pinpoint
pupils). The revised risk assessment uses the more sensitive endpoint of brain
cholinesterase inhibition from the carbaryl comparative cholinesterase study for both the
revised carbaryl and the N-methyl carbamate cumulative risk assessments. Brain
cholinesterase inhibition was selected as an endpoint, because this is an actual measure of
toxicity to the target tissue and the most sensitive endpoint. Red blood cell and plasma
cholinesterase inhibition are surrogate indicators of toxicity. A comparison of the oral rat
studies showed that brain cholinesterase inhibition is a more sensitive endpoint than is
red blood cell cholinesterase inhibition.
EPA used a benchmark dose analysis of the comparative cholinesterase study to
select points of departure for use in the revised risk assessment using the BMDLio for
postnatal day 11 pups. More details on the benchmark dose analysis for this study may
be found in the May 7, 2007, document, Report on Comparative Sensitivity Study of
Carbaryl. The BMDLio doses selected for points of departure were very similar to the
doses used for points of departure in the previous 2003 risk assessment. An exception
was the BMDLio for dermal toxicity, which was higher than the NOAEL used in the
previous risk assessment (30 vs. 20 mg/kg/day). The benchmark dose analysis allows for
a more accurate selection of a point of departure than the previously used NOAEL
approach, which is limited by dose levels selected in a given toxicology study.
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Table 3. Toxicological Endpoints for 2003 and 2007 Carbaryl Risk Assessments
Exposure Pathway
Acute Dietary
Chronic Dietary
Incidental Oral - short term
Incidental Oral - Intermediate
term
Dermal - short and intermediate
term
Dermal - long term
Inhalation - short term
Inhalation - long-term
Cancer, all routes of exposure
Toxicology Endpoint for Risk Assessment
2003/2004 IRED
Rat Developmental Neurotoxicity
(DNT) Study
Maternal NOAEL of 1 mg/kg/day
(LOAEL is 10 mg/kg/day, FOB
changes)
Chronic dog study LOAEL of 3 . 1
mg/kg/day and 3X to account for
data deficiency (no NOAEL)
Rat DNT study maternal NOAEL
of 1 mg/kg/day
Rat subchronic neurotoxicity
study NOAEL of 1 mg/kg/day
Rat 4-week dermal toxicity study
NOAEL of 20 mg/kg/day
(LOAEL of 50 mg/kg/day for
decreased RBC & brain ChE)
Chronic dog study LOAEL of 3 . 1
mg/kg/day and 3X to account for
data deficiency (no NOAEL);
dermal absorption factor of
12.7%
Rat DNT study NOAEL of 1
mg/kg/day
Chronic dog study study LOAEL
of 50 mg/kg/day and 3X to
account for data deficiency (no
NOAEL)
2007 Revision
Rat comparative cholinesterase
(CCA) study
Brain BMDL10 for pups at
postnatal day 11 (PND11) is 1.1
mg/kg/day*
Not appropriate due to rapid
recovery of cholinesterase
inhibition
Rat CCA Study
Pup brain BMDL10 of 1 . 1
mg/kg/day
Rat CCA Study
Pup brain BMDL10 of 1 . 1
mg/kg/day
Rat 4-week dermal toxicity study
BMDL10 of 30 mg/kg/day
adjusted to 86 mg/kg/day using
2.8x dermal penetration factor to
account for absorption across
human skin
Not appropriate due to rapid
recovery of cholinesterase
inhibition
Rat CCA Study
Pup brain BMDL10 of 1 . 1
mg/kg/day
Not appropriate due to rapid
recovery of cholinesterase
inhibition
Qi * of 8.75 x 10"4 (mg/kg/day)"1 based on incidence of
hemangiosarcomas in mice; classified as C carcinogen
*Brain BMDL10 for pups is protective for both adults and children according to a full BMD analysis of all
carbaryl oral toxicity data in adults.
In 2003, EPA believed it was appropriate to evaluate long-term (> 6 months) and
chronic exposure. However, this revised risk assessment does not include endpoints for
long-term exposure because of the rapid recovery of enzyme activity from inhibition by
carbaryl. Recent data for carbaryl and the other N-methyl carbamates show that
cholinesterase inhibition is reversible, with recovery in less than 24 hours. Both the
previous and present risk assessments evaluate potential cancer risk, but the cancer risk
assessment is not included in this tolerance reassessment document because the cancer
endpoints remain unchanged and were addressed in the carbaryl IRED. Current cancer
risk estimates for carbaryl are below the Agency's level of concern.
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Dermal exposure scenarios were adjusted using a dermal penetration factor of
2.8x. A comparative in vitro dermal penetration study showed that rat skin was 2.8x
more permeable to carbaryl than human skin (MRID 47151902). Therefore, for dermal
exposure scenarios, the BMDLio of 30 mg/kg/day was multiplied by 2.8 to derive the
point of departure (86 mg/kg/day) for risk assessment for dermal exposure scenarios. In
the 2003 carbaryl risk assessment, EPA used a 12.7% dermal absorption factor derived
from a rat dermal absorption study to convert dermal exposures to the equivalent oral
dose.
Table 4. Summary of Toxicology Endpoints, Uncertainty Factors, and Levels of
Concern for Revised Carbaryl Risk Assessment
Exposure
Scenario
Acute Dietary
All populations
Chronic Dietary
Incidental Oral
(All durations)
Dermal
(All durations)
Inhalation
(All durations)
Cancer
Point of
Departure
(mg/kg/day)
1.1
Uncertainty/FQ
PA Safety
Factors
UFA=10x
UFH=10x
FQPA SF=lx
RfD, PAD, Level of
Concern for Risk
Assessment
Acute RfD=0.01
aPAD=0.01
Study and Toxicological Effects
Comparative Cholinesterase Rat
Study- (MRID 47143001)
BMDio= 1.5 mg/kg and
BMDL10= 1.1 mg/kg, based on
brain ChE inhibition in post-natal
day 11 (PND 11) pups
Due to the rapid recovery of ChE activity, the acute exposure from carbaryl is the main duration
of concern and therefore a chronic assessment is not appropriate for carbaryl.
1.1
86
1.1
UFA=10x
UFH=10x
FQPA SF=lx
UFA=10x
UFH=10x
FQPASF=1.8x
(children only)
UFA=10x
UFH=10x
FQPA SF=1
MOE = 100
MOE= 100 (adult)
MOE= 180 (children)
MOE = 100
Comparative Cholinesterase Study -
(47143001)
BMD10= 1.5 mg/kg and
BMDL10= 1.1 mg/kg, based on
brain ChE inhibition in post-natal
day 11 (PND 11) pups
Rat Adult Dermal Study (MRID
45630601), Brain ChE inhibition
most sensitive, BMD10= 49.35
mg/kg andBMDL10= 30.56 mg/kg
Adjusted by 2.8x to account for rat
skin permeability compared to
human skin (MRID 47151902)
Comparative Cholinesterase Study -
(MRID 47143001), BMD10= 1.5
mg/kg andBMDL10= 1.1 mg/kg,
based on brain ChE inhibition in
post-natal day 1 1 (PND 11) pups
Classification: "Likely to be carcinogenic in humans"
Qi* = 8.75 x 4"4 (mg/kg/day)"1 based on incidence of hemangiosarcomas in mice
Notes: NOAEL = no observed adverse effect level. LOAEL = lowest observed adverse effect level. UF = uncertainty
factor. UFA is for interspecies extrapolation from animal to human. UFH is for potential intraspecies variation in
sensitivity among members of the human population. MOE = margin of exposure.
B. Summary of Revised Dietary and Residential Risk Assessments
The Agency revised the dietary and residential risk assessments for carbaryl to
incorporate the revised FQPA safety factor, new residues data, and recent information on
percent crop treated. The revised human health risk assessment may be found in the June
10
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29, 2007 document, CARBARYL. HED Chapter of the Reregistration Eligibility Decision
Document. Details of the dietary risk assessment for food and water may be found in the
June 27, 2007, document: Carbaryl Acute Probabilistic Aggregate Dietary (Food and
Drinking Water) Exposure and Risk Assessment for the Reregistration Eligibility
Decision. Details of the residential risk assessment may be found in the June 29, 2007
document, Carbaryl: Revisions to Residential Exposure and Risk Assessment and in the
September 21, 2007 document, Carbaryl: Addendum to the "HED Chapter of the
Reregistration Eligibility Decision Document (RED). "
1. Dietary Risk from Food and Drinking Water
Food
For the revised carbaryl dietary risk assessment, EPA evaluated dietary exposure
to residues in food using the same dietary exposure model and food consumption data
used in the 2003 IRED [Dietary Exposure Evaluation Model with the Food Commodity
Intake Database (DEEM-FCID)]. The dietary risk assessment was updated to
incorporate the most recent residue data from USDA's PDF program, as well as the most
current information on percent of crop treated with carbaryl for various food
commodities.
EPA's revised dietary risk assessment for food shows that acute dietary exposure
and risk are below the Agency's level of concern for the general U.S. population and all
population subgroups; exposure to carbaryl residues in food comprises <100% of the
acute population adjusted dose (aPAD) at the 99.9th percentile of exposure. Estimated
dietary exposure for the general U.S. population is 29% of the aPAD; exposure to
children age 1-2 years, the most highly exposed population subgroup, comprises 60% of
the aPAD. Table 6 below summarizes acute dietary risks from food to other population
subgroups. As previously mentioned, EPA did not evaluate dietary risk for chronic
exposure to carbaryl due to the rapid reversibility of cholinesterase inhibition, the
toxicological endpoint of concern.
Table 5. Summary of Acute Carbaryl Dietary Risk from Food.
Population Subgroup
General U.S. Population
All Infants (< 1 year old)
Children 1-2 years old
Children 3-5 years old
Females 13-49 years old
% Acute Population Adjusted Dose (aPAD)
at the 99.9th Percentile
29
40
60
54
23
EPA conducted a sensitivity analysis on the carbaryl dietary assessment to
determine how using data from various sources (i.e., PDF vs. FDA monitoring data)
impacted dietary risk estimates. The Agency did this analysis for carbaryl because PDF
data are considered to be the best available residue data for dietary risk assessment and
because the N-methyl carbamate cumulative risk assessment uses only PDF residue data
11
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for food. When only commodities with PDF data were included in the dietary
assessment, the estimated dietary exposure for the general U.S. population was reduced
to 17% of the aPAD and the dietary exposure for children age 1-2 years was reduced to
50% of the aPAD.
The Agency also conducted a critical commodity contribution analysis for
carbaryl to determine the commodities contributing the most to dietary exposure,
especially to children. From this analysis, EPA determined that carbaryl residues on
strawberries are the most significant source of dietary exposure to children age 1-2.
Carbaryl residues on strawberries were also identified as the main contributor to dietary
risk to young children in the 2003 dietary assessment.
Drinking Water
For the revised carbaryl risk assessment, EPA incorporated estimated pesticide
residues in drinking water directly into the exposure component of the dietary
assessment, using the DEEM-FDIC model. Drinking water consumption data and
reported body weights from the Combined Survey of Food Intake by Individuals (CSFII)
are incorporated into the exposure assessment. A 30-year distribution of drinking water
residue values, estimated by modeling carbaryl concentrations in surface water over time
(time series values), is incorporated into a probabilistic dietary assessment. The 2003
IRED presented both this methodology and the old methodology, using drinking water
levels of comparison (DWLOCs).
The Agency also incorporated new half-life data from an aerobic aquatic
metabolism study, regional percent cropped area factors, and the mitigation required in
the carbaryl IRED into modeled estimates. Representative carbaryl use scenarios chosen
for drinking modeling are summarized in Table 6. The Agency used the PRZM-EXAMS
model to generate a distribution of approximately 11,000 values, representing daily peak
values over 30 years. This data set was used to create water residue data files for use in
DEEM-FCID. The range of annual peak water values was 13-108 ppb over 30 years.
One in ten year peak values are summarized in Table 6 below; other modeled values are
not presented because they are not relevant to the risk assessment. Details of EPA's
refined drinking water modeling may be found in the March 13, 2007, document,
Carbaryl Refined Drinking Water Time Series Simulations Using Regional PC As.
Table 6. Surface Water Modeling for Representative Carbaryl Use Scenarios.
Modeling
Scenario
Georgia
Peaches with
optional
Dormant Spray
Georgia
Peaches
without
Relevance
Entire US
Entire US
Regional
PCA
0.38
0.38
Application type
Aerial application; 3
applications in season at
3 Ib ai/A and; single
dormant application at 3
Ibai/A
Aerial application; 3 in
season applications at 3
Ibai/A
Application
Dates
July 1, 8, 15;
October 15
July 1, 8, 15
Peak l-in-10 yr
Surface Water
Concentration
21
21
12
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Modeling
Scenario
optional
dormant Spray
California
Peaches with
optional
dormant spray
California
Peaches
without
optional
dormant spray
Florida Citrus
California
Citrus
California
Citrus SLN
California
Grapes
PA Apple
Apple Oregon
FL Strawberry
CA strawberry
Relevance
CAonly
CAonly
FL only
CAonly
CASLN
only
CAonly
Mid Atlantic
Western
Apples
Entire US
CAonly
Regional
PCA
0.56
0.56
0.38
0.56
0.56
0.56
0.46
0.63
0.38
0.56
Application type
ground spray; 3 in
season at 3 Ib and 1
dormant at 3 Ib (Note
that due to model
implementation
difficulties, the last
application is 1 Ib in
excess of max seasonal)
3 in season at 3 Ib, 7
day interval, aerial
three 5-lb applications,
14 day interval aerial
three 5-lb applications,
7 day interval, aerial
single 12-lb application,
aerial
five 2 Ib applications,
aerial
five 3-lb applications,
14 days interval, aerial
five 3-lb applications,
14 days interval
five 2-lb applications,
ground spray
five 2-lb applications,
ground spray
Application
Dates
July 1, 8, 15;
October 15
July 1, 8, 15
January 4, 18,
February 1
January 4, 18,
February 1
January 4
June 1, 8, 17,
24, July 1
June 1, 15, 29,
July 12, 26
April 15, 29,
May 11,25,
June 4
January 3, 10,
17,
24,February 1
March 3, 10,
17,24,31
Peak l-in-10 yr
Surface Water
Concentration
21
21
66
35
44
30
108
27
64
58
EPA also conducted a review of all readily available surface water monitoring
data for carbaryl to evaluate any changes in surface water concentrations of carbaryl in
urban and suburban streams with the phase out of residential uses of the pesticides
chlorpyrifos and diazinon. The results of this review are summarized below. Details of
EPA's updated drinking water assessment may be found in the May 2, 2007 document,
Revised Carbaryl Drinking Water Assessment Including Time Series Simulations and a
March 13, 2007 document, Carbaryl Refined Drinking Water Time-series Simulations
Using Regional PC As.
Surface Water Monitoring
The Agency has reviewed surface water monitoring data for carbaryl that has
become available since the completion of the IRED in 2003. New information on
available surface watering data for carbaryl is summarized below. EPA has focused on
data sources providing information on residues of carbaryl in surface water as a result of
13
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urban and suburban use. These data show that carbaryl is commonly found in surface
water of both agricultural and urban watersheds. It is found more often in urban
watersheds. Higher concentrations are reported for agricultural watersheds than for urban
watersheds. Three sources of water monitoring data that were considered in the carbaryl
IRED and are still relevant are the Pilot Reservoir Monitoring Study, a Bayer Drinking
Water Monitoring Study for Carbaryl, and a joint USGS-EPA Mini-pilot Monitoring
Program. Additional details may be found in the May 2, 2007 document, Revised
Carbaryl Drinking Water Assessment Including Time Series Simulations.
EPA has also considered the impact of the recent phase out of residential uses of
chlorpyrifos and diazinon, two widely used home and garden pesticides. There has been
some speculation that carbaryl use would increase with the phase out of diazinon and
chlorpyrifos, resulting in higher levels of carbaryl in urban and suburban watersheds.
Although the long term impact of the phase out on carbaryl surface water concentrations
is unclear, EPA has not observed a steady trend toward increased levels of carbaryl in
surface water.
National Water Quality Assessment (NA WQA) Monitoring Program. For the
2003 carbaryl IRED, the Agency reviewed the available data from the US Geological
Survey (USGS) NAWQA program, sampled between 1991 and 1998. In 2006, USGS
published a NAWQA report summarizing results from 1992-2001. Carbaryl was listed in
this 2006 report as one of the 14 most frequently detected pesticides in surface water (one
of the three most frequently detected insecticides). This report also noted that carbaryl
was detected in 50% of urban samples; with roughly 35% of urban samples reporting
carbaryl levels < 0.1 ug/L. For this tolerance reassessment, EPA also reviewed NAWQA
monitoring data collected between 1999 and 2005. For the more recent data, 29% of
samples showed detections; the mean concentration of detections was 0.058 ug /L, with a
lower detection frequency associated with agricultural uses than with urban uses. During
this time period, samples collected from an agricultural region showed roughly 19%
detects while samples representing urban and suburban uses showed roughly 50%
detects. The maximum concentration reported was 33.5 ug/L, which was associated with
agricultural use of carbaryl. The highest concentration reported in an urban stream was
16 ug/L in Denver, CO. The Agency believes that the frequency of carbaryl detections in
urban streams is consistent both with EPA's 2003 drinking water assessment and with
earlier data.
USGS-EPA Mini-pilot Monitoring Program. In September 2000, an
Intergovernmental Steering Committee and workgroups were formed to design and
implement monitoring programs in support of regression model development efforts.
The purpose of the monitoring was to resolve technical and logistical issues for
development of a larger monitoring program. Phase I of the project sampled water-
supply intakes for five community water systems (CWS) that withdraw from free-flowing
surface-water bodies. Sampling was scheduled approximately 90 times over the course
of a year, occurring most frequently during the primary pesticide application and
pesticide runoff periods. Sites were selected to represent a variety of cropping regions
and pesticide usage in areas dependent on precipitation-based agriculture. Samples were
14
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shipped overnight in iced coolers to the USGS National Water-Quality Laboratory in
Denver Co. for analysis. Low levels of carbaryl were found at several of the monitoring
locations, with no sample measuring greater than 1 ug/L.
Surface Water Monitoring Program for Pesticides in Salmonid-bearing Streams.
The Washington State Departments of Agriculture and Ecology monitored selected
salmonid bearing streams for pesticides during the typical pesticide use season (Burke et
al. 2006). This study evaluated watersheds collecting potential surface water runoff from
both urban and agricultural regions. Urban regions were represented by Thornton Creek
in the Cedar-Sammanish Watershed, a 12.1 square mile area with 75,000 to 100,000
residents, encompassing single family homes, apartment complexes, and schools. Paved
impervious surfaces cover 50% of this watershed. Agricultural regions were represented
by the Lower Yakima Watershed, which drains an agricultural basin where numerous
crops, including grapes, apples and other fruit trees, wheat, asparagus, hops, mint, and
potatoes are grown. Agricultural crops cover 47% of this watershed of 216,168 acres.
Water from Yakima River systems is managed by US Bureau of Reclamation; while local
irrigation districts manage water distribution to farms via canals. Three water bodies
were monitored in the Lower Yakima Watershed: Marion Drain, Sulphur Creek
Wasteway, and Spring Creek.
From 2003-2005, 78 sampling events occurred in the urban Thornton Creek
watershed. Carbaryl was not detected in any sample above the mean lower practical
quantitation limit, which varied over this time from 0.19 |ig/L (2003) to 0.13 |ig/L (2004)
to 0.11 ug/L (2005). Carbaryl was detected in samples collected in the agricultural
Lower Yakima watershed (which includes the Marion Drain, the Sulfur Creek Wasteway,
and Spring Creek). In 2003 carbaryl was detected in the Marion drain at 0.14 |ig/L (in 1
of 18 samples); carbaryl was not detected in 2004 or 2005 at this location. Carbaryl was
detected in 2004 in the Sulfur Creek Wasteway at 0.16 jig/L g/L (in 1 of 31 samples);
carbaryl was not detected in 2003 or 2005 at this location. On June 18, 2003, carbaryl
was detected at a concentration of 10 |ig/L in the upper Spring Creek station, and 1.7
|ig/L at the mid-Spring Creek station.
The Washington State Departments of Agriculture and Ecology also reviewed the
USGS NAWQA data for the Cedar-Sammanish and Lower Yakima Watersheds, dating
back to 1996. USGS monitoring for these watersheds captured changes in pesticide use,
including the phase out of residential uses of diazinon in December 2004. Washington
State Departments of Agriculture and Ecology reviewers concluded that carbaryl
detection rates have increased slightly over time.
Environmental Monitoring of Carbaryl in Urban Areas in California. The
Environmental Monitoring Branch of California's Department of Pesticide Regulation
(DPR) measured environmental concentrations of carbaryl and other pesticides in
selected media following ground applications of pesticides to control the glassy winged
sharpshooter, an insect causing severe damage to California grapes. After spraying
carbaryl in five urban areas to control this pest, California's DPR monitored carbaryl
residues in pesticide tank mixtures and in air, surface water, foliage, and backyard fruits
15
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and vegetables. DPR found only three detections of carbaryl in surface water1, and
concluded that carbaryl spraying in urban areas to control the glassy winged sharpshooter
did not result in significant human or environmental exposure.
Groundwater Monitoring
The carbaryl IRED reported a 1987 groundwater monitoring value of 610 |ig/L
from Suffolk County New York. Because this value was significantly higher than any
other monitoring values from ground or surface water, EPA contacted the Suffolk County
government for more information about this particular groundwater sample. The sample
associated with that concentration (the actual concentration was 61,000 |ig/L) was taken
from a sump at a pesticide mixer/loader site as part of a pesticide spill investigation, not
from a groundwater monitoring well. Therefore, this value should not have been reported
in the Suffolk County water quality database (SCDH, 2007, personal communication);
EPA has removed it from the carbaryl drinking water assessment. There were a small
number of detections of carbaryl reported to OPP as a result of a quality control check of
the Suffolk County database, ranging from 0.1 to 13 |ig/L. These values are more in line
with other monitoring data for carbaryl reported in the EPA assessment.
2. Risk from Residential Uses of Carbaryl
The Agency revised the residential risk assessment for carbaryl to incorporate the
revised toxicology endpoints and FQPA safety factor, the mitigation specified in the
IRED, and confirmatory data received as a result of the generic DCI for carbaryl. EPA
received turf transferable residue (TTR) data for granular formulations of carbaryl, as
well as additional data to support the use of carbaryl in pet collars. The granular TTR
data were incorporated into the revised risk assessment; however, the pet collar data were
considered but not incorporated because of data quality issues. In addition, the Agency
incorporated data from several studies for pesticides applied to turf to estimate the
percent of carbaryl transferred from turf to a person's hand. Details of the revised
carbaryl residential risk assessment may be found in the June 29, 2007 document,
Carbaryl: Revisions to Residential Exposure and Risk Assessment and in the September
21, 2007 document, Carbaryl: Addendum to the "HED Chapter of the Reregistration
Eligibility Decision Document (RED). "
Mitigation Specified in IRED
At the time of the 2003 carbaryl IRED, EPA had risk concerns for several
residential uses of carbaryl. To address these risk concerns, the IRED specified the
following mitigation measures, which are now being implemented through revised
product labeling:
Cancellation of all pet uses except flea collars, all aerosol products, application of
granular and bait products to lawns either by hand or using a belly grinder;
1 DPR found a high detect in 1 sample, from a furrow in a field adjacent to a treated area. This is attributed
to rainfall runoff and is not believed to be significant.
16
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Special packaging for all carbaryl dust products for use in home gardens (ready to
use shaker can, containing no more than 0.05 Ib a.i. carbaryl per container); and
Requirement that all carbaryl liquid products be packaged in pint size containers
for use with hose-end sprayers; use on lawns limited to spot treatment.
In addition, EPA required confirmatory data for the granular turf use and the pet
collar use. These data requirements are described below.
Confirmatory Data from 2005 Generic DCI
EPA received post-application exposure studies as a result of the March 2005
generic DCI for carbaryl: a new turf transferable residue (TTR) and handpress study for
granular carbaryl (MRID 46673901), submitted by Bayer CropScience, and a dog petting
and rate of release transferable residue study for dog collars impregnated with carbaryl
(MRIDs 45792201, 46075601 and 46015001), submitted by Wellmark International.
(Some of the Wellmark data have been previously submitted.) The data from the TTR
study, which is described below, was incorporated into the revised residential risk
assessment for carbaryl. However, the data from the pet collar studies could not be used
in the revised risk assessment due to issues with quality assurance, quality control, and
documentation of data. (See the December 5, 2006 document, [Review of] Transferable
residues from dogs treated with 16% carbaryl collar, MRIDS 45792201, 46015001, and
46075601, for details.) Therefore, these pet collar studies are considered unacceptable,
do not meet the DCI requirement, and are not used for quantitative risk assessment
purposes.
In the turf transferable residue (TTR) study, data were collected from three sites
(Molino, FL; Stilwell, KS; and Fresno, CA) by means of a modified California roller and
handpress on turf after the application of 8 Ib ai/A of Sevin 2G (2% granular carbaryl).
TTR data were collected for both irrigated and nonirrigated turf, and handpress data were
collected using both moist and dry hands. Data were collected immediately after
application and at 4, 12, and 24 hours and 2, 3, 5, and 7 days after application. The
registrant submitted additional data collected for 24 hours at 30 minute increments at the
Molino, FL, site as a study addendum.
Residential Exposure Scenarios
There are far fewer potential residential exposure scenarios today than at the time
of the carbaryl IRED because of numerous product cancellations and the mitigation
described above. As previously mentioned, two-thirds of all carbaryl products registered
at the time of the IRED (June 2003) have been voluntarily cancelled. At the present time,
95 carbaryl products are registered.
For the 2007 carbaryl revised residential risk assessment, EPA evaluated the
following residential handler scenarios:
17
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Home gardens, application with ready-to-use trigger sprayer, hose-end sprayer,
ornamental duster, or low-pressure handwand;
Trees and ornamentals, application with hose-end sprayer or low-pressure
handwand;
Lawncare, application of liquid product with hose-end sprayer;
Lawncare, application of granular and bait products with push-type spreader;
Pet collars impregnated with carbaryl for dogs and cats; and
Garden and ornamentals, paint on or sprinkler can application.
The Agency evaluated potential exposure and risk to residential handlers, who
would be applying carbaryl products and post-application risk to adults, children, and
toddlers who could be reentering a carbaryl treated lawn or garden, playing with pets
wearing carbaryl pet collars, or harvesting fruit and vegetables from home gardens.
Because the carbaryl technical registrant, Bayer CropScience, has recently requested that
EPA allow a larger package size for garden dust products, the Agency has also evaluated
potential risks from such a scenario.
Risk to Residential Handlers
EPA's revised risk estimates for residential handlers were not of concern for
carbaryl for any use scenario; i.e., MOEs were all greater than 100. MOEs for residential
handlers ranged from 280 to 34,000 for combined inhalation and dermal exposure. The
lowest combined MOE (highest risk estimate) is 280 for application of 10% carbaryl dust
to vegetable gardens and/or ornamentals. Therefore, EPA does not have a risk concern
for residential handlers.
Residential Post-application Risk
Exposure Scenarios
EPA evaluated potential risks from the following post-application exposure
scenarios in the revised residential risk assessment for carbaryl:
Adults
Incidental dermal contact with carbaryl residues on turf (lawns and golf
courses) from mosquito adulticide use;
Dermal contact with carbaryl residues on treated deciduous trees;
Dermal contact with carbaryl residues on treated vegetable gardens;
Dermal contact with carbaryl residues from Washington state oyster bed
use (oyster harvesting and swimming);
Dermal contact with carbaryl residues from doing heavy yard work on turf
treated with granular formulations; and
Dermal contact with carbaryl residues from golfing on turf treated with
liquid or granular formulations;
18
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Children (Age 10-12 years)
Dermal contact with carbaryl residues on treated deciduous trees; and
Dermal contact with carbaryl residues on treated vegetable gardens;
Toddlers (Age 3 years)
Dermal contact and incidental oral ingestion of residues from hugging a
pet wearing a carbaryl-impregnated flea collar;
Dermal contact with residues on turf from mosquito adulticide use;
Dermal contact with carbaryl residues from Washington state oyster bed
use while playing on beach; and
Dermal and incidental oral ingestion of carbaryl residues from treated
residential turf.
The Agency assumed that post-application exposure to adults and older children
would be limited to the dermal route, but that toddlers could receive both dermal and
incidental oral exposure. EPA assumes that toddlers could be mouthing grass from
treated lawns, eating soil from treated lawns, mouthing their hands after touching a
treated lawn, or hugging a pet wearing a carbaryl-impregnated flea collar. Although EPA
could combine incidental oral exposure from all three potential incidental oral exposure
pathways for screening purposes, the Agency does not believe that such a scenario is
likely to occur and combining high-end exposure estimates from already conservative
exposure scenarios would result in risk estimates associated with toddler behaviors that
are unrealistic. For example, the Agency considers it unreasonable to assume a toddler,
presumably under some degree of supervision and care, would be playing on a lawn
immediately after the lawn was treated with carbaryl (at the maximum rate after watering
in) and the toddler would be putting both hands on the ground and then in his or her
mouth, eating a handful of grass, and eating soil, all within the same 2 hour time period.
In addition, each of these activities is assumed to occur multiple times, over the 2 hour
time period, with the same amount of pesticide residue picked up and ingested each time.
For example, EPA assumes that a toddler would have 20 hand-to-mouth events per hour,
which reflects the high-end (90th percentile) of exposure from observational data on
children's activities. For each of these incidental oral scenarios, EPA assumes a high
amount of residues would be transferred to a child's hand or be found in the grass or soil
that is eaten. EPA believes that these assumptions, especially when taken together,
would significantly overestimate children's exposure to carbaryl. Therefore, EPA
assessed a number of reasonably realistic, and representative, toddler post-application
scenarios.
The major assumptions underlying each of the toddler exposure scenarios are
listed below:
Dermal Exposure
From Lawn
Child playing on a wet lawn immediately after carbaryl is applied and watered- in
Child plays on lawn for 2 hours
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Child places both hands on grass (area of 20 cm2 contacts grass) and picks up
significant residues from blades of grass (5200 cm2/hour)
From Pet Collar
Child hugs a medium size (30 Ib) dog and residues are transferred from fur to
hands and forearms
20% of available carbaryl in pet collar is evenly distributed over dog's fur and
residues are available for transfer to child for each event
Child plays with dog for 2 hours
Incidental Oral Exposure
Hand- to-Mouth Pathway
Child puts hand in mouth 20 times/hour
Child ingests all pesticide residues on his hand
Child picks up the same amount of residues each time and ingests them all
Object-to-Mouth Pathway (Eating Grass)
Child mouths all of the grass from 4 square inches of lawn per day
Residue levels on grass equal 3-5% of maximum application rate for carbaryl
Soil Ingestion Pathway
Soil residues in top layer of soil equal 100% of maximum application rate for
carbaryl
Child ingests 100 mg of soil per day
Risk Estimates
Risk estimates for a single route of exposure to adults, children, and toddlers are
expressed as MOEs. EPA has a risk concern for dermal MOEs < 180 and for oral MOEs
< 100, as shown in Table 4. Risk estimates for toddlers exposed by multiple routes of
exposure are expressed as an Aggregate Risk Index (ARI) because EPA has different
levels of concern for oral and dermal exposure to toddlers. For toddlers, EPA calculated
ARIs for scenarios combining risk from dermal exposure with risks from certain oral
exposure pathways, such as eating grass or mouthing their hands after touching a treated
lawn. The Agency generally has a risk concern for ARIs < 1.
Adults. Dermal MOEs for adults from post-application exposure to granular
carbaryl on turf range from 720 to 63,000 when the pesticide is watered in after
application; and from 380 to 38,000 when the pesticide is not watered in. Dermal MOEs
for adults range from 930 to 27,000,000 for all other scenarios. Therefore, EPA does not
have a risk concern for adults for any post-application exposure scenario.
Children age 10-12 years. Children (age 10-12 years) working in home vegetable
gardens treated with carbaryl have post-application dermal MOEs ranging from 4,200 to
8,400. Children working in home orchards treated with carbaryl have post-application
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dermal MOEs ranging from 1,000 to 31,000. Because all of these MOEs exceed 180,
EPA's level of concern for this age group, the Agency does not have a risk concern for
post-application exposure to children age 10-12.
Toddlers. EPA has calculated separate dermal and incidental oral MOEs for
toddlers exposed to carbaryl residues from the potential scenarios described above. In
addition, EPA has calculated risk to toddlers from combined dermal and incidental oral
exposure (hand-to-mouth or object-to-mouth pathways) to account for the possibility that
toddlers could be exposed to pesticide residues from both oral and dermal routes on the
same day, potentially at the same time, from use of a single carbaryl product.
EPA has calculated separate dermal and incidental oral MOEs for toddlers
exposed to carbaryl residues on turf as a result of the carbaryl lawn care use. As shown
in Table 7 below, dermal MOEs for toddlers playing on treated turf range from 230 to
3,100, and are not of concern. These risk estimates were derived from the new TTR
study (MRID 46673901) which measured carbaryl residues on turf following the
application of Sevin 2G at a rate of 8 Ib ai/A with a drop spreader. EPA also assumed 2
hours of exposure/day, and a transfer coefficient of 5,200 cm2/hour. Transferable
residues were measured using both the California roller and handpress methods. The
handpress data, collected only at the Kansas site, were used to assess children's hand-to-
mouth exposure.
Table 7. Post-application Dermal Risks to Toddlers from Use of Sevin 2G on Turf
Turf Transferable Residue
Study Site
Florida
Florida Study Addendum
California
Kansas (rain during study)
Short-term Post-application Dermal MOEs for Toddlers*
Non-Irrigated
230
1,600
270
760
Irrigated
430
Not Applicable, No
Irrigation or Rainfall
3,100
2,600
* Dermal MOEs > 180 are not of concern.
Toddler risks from the three potential pathways of incidental oral exposure to
carbaryl are summarized in Table 8 below. Oral MOEs for hand-to-mouth exposure to
toddlers range from 71 to 720; MOEs for object-to-mouth exposure range from 150 to
250; and the MOE for soil ingestion is 2,800.
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Table 8. Post-application Incidental Oral Risks for Toddlers Playing on Turf
Exposure Pathway
Hand-to-Mouth
Obj ect-to-Mouth
Soil Ingestion
Range of Short
Term Incidental
Oral MOEs
71-720
150-250
2,800
Residue
Available for
Transfer
100%
3-5%
100%
Data Source/
Methodology
Carbaryl TTR Study, Kansas
data (MRID 46673901)
Residue data from multiple
turfgrass studies, Residential
SOPs
Residential SOPs
Handpress data from the Kansas site were used to calculate hand-to-mouth
incidental oral exposure and risk. These were the only handpress data available.
Handpress data were collected with both dry and moist hands to simulate a toddler's
mouthing behavior. These data were also collected for irrigated and nonirrigated test
plots to allow the Agency to evaluate risk from a variety of potential scenarios. EPA
calculated MOEs for each of these possible scenarios, as shown in Table 9.
Table 9. Toddler Hand-to-Mouth Risks based on TTR Data from Kansas site
Type of
Handpress
Dry
Moist
Short-Term Oral MOE
Non-irrigated
170
71
Irrigated
720
500
MOEs calculated for dry and wet hands contacting irrigated turf are 720 and 500,
respectively, and therefore not of risk concern. Likewise, the MOE for dry hands
contacting non-irrigated turf is 170 and not of risk concern. The MOE for wet hands
contacting non-irrigated turf is 71, and is below 100, EPA's level of concern. At present,
labels for all granular residential use products specify that people or pets contain the
following language:
"Do not allow people or pets to enter the treated area until dusts have settled. In
addition, if directions for use require watering-in, do not allow people (except those
involved in the watering-in) or pets to enter the treated area until the watering-in is
completed and the area has dried. "
Most carbaryl granular products for homeowner use recommend watering in so that the
product can effectively control soil-borne insect pests, such as mole crickets and white
grubs. As part of this RED, EPA will be requiring that all labels for granular turf
products for residential use require watering-in.
Moreover, EPA believes that the MOE of 71 is conservative and likely overstates
actual risk for several reasons. The Agency's current screening-level methodology2 to
estimate hand-to-mouth exposure to toddlers incorporates several conservative
assumptions. EPA assumes that a toddler is exposed to residues immediately following
: EPA used methodology from the Residential Standard Operating Procedures (SOPs)
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application of carbaryl at the maximum rate, 8 Ibs ai/A, which represent a worst case
exposure scenario. The Agency assumes that a toddler is playing on a lawn that has just
been treated with carbaryl and that the child remains on the lawn for 2 hours. EPA also
assumes that an area of 20 cm2 (palms of both hands) comes into contact with the treated
lawn and that the child ingests all of the pesticide residues on his hand. The Agency
further assumes that 100% of the residues picked up and ingested the first time are
replenished each subsequent time the child contacts the treated lawn, and ingested each
subsequent time the child puts his hand in his mouth. In addition, EPA assumes that the
child puts his hand in his mouth 20 times per hour, for 2 hours per day, for a total of 40
hand-to-mouth events per day. The number of hand-to-mouth events represents the 90th
percentile of observational data on mouthing behavior by young children3.
Moreover, because most labels for granular carbaryl lawn care products
recommend watering-in after application, EPA believes that the residue values and
exposure estimates for irrigated turf are more representative of actual use than values
from non-irrigated turf. Furthermore, as previously mentioned, the Agency will be
requiring that all labels for carbaryl granular turf products be modified to require
irrigation, or watering-in after product application to turf.
In summary, EPA believes that the label requirement to water in granular carbaryl
residential turf products after application reduces the potential risk concern for toddlers.
Given the conservativeness of this screening-level exposure scenario (complete
removal/ingestion of residues on the hand, full replenishment of residues, and 40 hand-to-
mouth activities per day) and considering the label requirement for watering-in, which
would result in lower exposures and acceptable MOEs, the Agency does not have a risk
concern for children's hand-to-mouth exposure resulting from the use of carbaryl
granular turf products.
EPA has combined incidental oral (hand-to-mouth and/or object-to-mouth
pathway) and dermal risk estimates for toddler post-application exposure scenarios
associated with playing on turf following aerial or ground spraying of carbaryl as a
mosquito adulticide; playing on a beach following use of carbaryl to treat oyster beds;
playing with (hugging) a pet wearing a carbaryl flea collar; and playing on treated lawns.
Toddler post-application risk estimates are presented as ARIs; EPA typically has
a risk concern for ARIs < 1. Post-application ARIs for toddlers exposed by both
incidental oral and dermal routes range from 0.92 to 420, and are not of concern.
Although the ARI for combined dermal and object-to-mouth exposure for a child playing
on a treated lawn is 0.92, this value is based on object-to-mouth exposure derived from
use of liquid rather than granular products on turf because these are the only available
data. Granular turf products are expected to fall to the underlying thatch or soil, reducing
the amount of foliar residue available; whereas liquid products are expected to remain on
turf and be more available for transfer. Also, this value does not reflect watering-in,
3 Data from observational studies on young children show a mean of 6 hand-to-mouth events per hour; 20
hand-to-mouth events per hour represents the 90th percentile of the data and should therefore be considered
a high-end value (Xue et al, 2007).
23
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when granulars/residues are less likely to be available. Post application risks to toddlers
are summarized in Table 10.
Table 10. Post-application Risks to Toddlers from Oral and Dermal Exposure
Use Scenario
Mosquito Adulticide
(ground application)
Mosquito Adulticide
(aerial application)
Oyster Beds
(Washington SLN)
Pet Collar Use
Lawn Care Use
Lawn Care Use
Exposure Scenario
Incidental residues
from residential lawn
Beach Play
Child Hugging Pet
Child Playing on Lawn
Child Playing on Lawn
Co-occurring Exposure Pathways
Dermal + Hand-to-Mouth
Dermal + Hand-to-Mouth
Dermal + Hand-to-Mouth
Dermal + Hand-to-Mouth
Dermal + Hand-to-Mouth
Dermal + Object-to -Mouth
Aggregate Risk
Index (ARI)
6.7
13
420
1.6
1.6
0.92
The Agency did not consider it reasonable or realistic to combine toddler risks
from post-application scenarios, such as the pet flea collar with lawn care products. The
ARIs for the lawn care and pet collar exposure scenarios are essentially equivalent, given
the precision of the underlying data and assumptions used in the risk estimates, and
indicate that the combined dermal and oral exposure risks are comparable for both use
scenarios. Therefore, if a toddler were playing on a lawn for 2 hours immediately after it
was treated with carbaryl (at the maximum rate and after the product was watered-in) and
at the same time playing with a dog that has a carbaryl pet collar, the potential screening-
level risk is no greater than the independent estimates associated with the lawn or pet
collar scenarios, assuming a toddler can not have both of its hands on the grass and the
dog at the same time or have its mouth on the grass and the dog at the same time.
An example of another possible scenario would entail a toddler playing for two
uninterrupted hours with a pet that has a carbaryl pet collar and immediately thereafter
playing for two uninterrupted hours on a lawn that was just treated with carbaryl at the
maximum rate. In this hypothetical scenario a toddler, presumably under some degree of
care and supervision, would spend an uninterrupted four hour period playing with a pet
wearing a carbaryl pet collar and subsequently playing for two hours on a lawn freshly
treated with carbaryl, without engaging in any other activity for the entire period of time.
The Agency concludes that assuming such a pattern of behavior unrealistic and an
unreasonable conceptual model from which to formulate screening-level risk estimates.
To the extent that the activities of playing with a dog wearing a carbaryl collar and
playing on a lawn just treated with carbaryl are separated by an activity not associated
with carbaryl exposure, recovery to any adverse effect would occur, because carbaryl,
like the other N-methyl carbamates, causes a reversible effect (cholinesterase inhibition).
Thus, carbaryl exposure events separated by any other activity are essentially
independent.
In addition, because carbaryl pet collars and granular lawn products comprise a
fairly small market share, EPA does not expect that co-exposure or sequential exposure to
these products is likely to occur. The Residential Exposure Joint Venture (REJV)
24
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database estimates that 1.2% of all households apply carbaryl as a lawn treatment4, and
0.1% of households apply granular carbaryl. EPA's 1990 National Home and Garden
Pesticide Use Survey estimates that 1% of all households apply carbaryl to lawns.
Details of this analysis may be found in the July 13, 2007 document, Alternative[s]
Assessment for Carbaryl Use on Residential Lawns. EPA has also reviewed available
data on use of carbaryl and various other pesticides in pet collars. In 2005, pet collars
occupied an estimated 9% of the market share for pet flea and tick products, compared
with liquids (including shampoos, dips, and spot-on treatments) with approximately 66%
market share; oral tablets with approximately 17% market share; and other products
(aerosols, foggers, soaps, etc) with <10% market share5. Further, carbaryl is one of
several available insecticides used in impregnated flea collars. Propoxur, methoprene,
and tetrachlorvinphos are more commonly formulated in flea collars than carbaryl.
Details of EPA's analysis of alternative pet collars may be found in the September 24,
2007 document, Alternatives Assessment for Carbaryl Impregnated Flea and Tick
Collars on Dogs and Cats. Because of the small market share for each of these products,
EPA does not believe that a toddler will be exposed simultaneously or sequentially to
carbaryl residues from a pet collar and carbaryl residues on a treated lawn.
3. Aggregate Risk
Acute Aggregate (Food and Water)
When exposure from food and drinking water are combined, dietary exposure
comprises 61-66% of the aPAD for children 1-2 years old and 40-85% of the aPAD for
infants less than 1 year old, the most highly exposed population subgroup. Therefore,
acute aggregate risk is below the Agency's level of concern.
Short-term Aggregate (Food, Water, and Residential)
EPA considered short-term aggregate risk for both adults (handler and post-
application exposure) and children (post-application exposure only). Short-term
aggregate risk to adults is expressed as an MOE. Aggregate risk to children is expressed
as an ARI derived by combining exposure and risk from food, drinking water, and post-
application residential exposure. EPA has risk concerns for an aggregate MOE less than
100 and for an ARI less than 1.
When average exposure to carbaryl residues in food and drinking water is
combined with short-term exposure to adults applying carbaryl dust products in their
home gardens, the aggregate MOE is 510 and not of risk concern. Likewise, aggregate
risk from post-application exposure to adults who are performing heavy, high contact
work in the yard or garden, results in MOEs ranging from 640 to 800, which are not of
concern. Short-term aggregate risks to adults are summarized in Table 11 below.
Aggregate MOEs for adults range from 510 to 800 and are not of concern.
4 The REJV did not distinguish between liquid and granular lawn care products. EPA has limited use of
liquid products in a residential setting to spot treatment.
5 EPA proprietary data.
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Table 11. Summary of Carbaryl Aggregate Risks to Adults
Residential Exposure
Scenario
Dietary MOE
(food + water)
Residential MOE
(dermal)
Aggregate MOE
Residential Handlers
Application of carbaryl
garden dust
5600
560*
510
Residential Post-application
Thinning Deciduous
Trees
Heavy Yard Work (after
application of granular
carbaryl to lawn)
5600
5600
930
720
800
640
* Represents combined dermal and inhalation exposure.
Short-term aggregate risks for children are summarized in Table 12 below. When
risk from average exposure to carbaryl residues in food and drinking water is combined
with post application risk to children working in a home orchard, the ARI is 5, and not of
concern. Likewise, when risk from dietary exposure to carbaryl residues is combined
with post-application risk to toddlers, the ARI ranges from 0.9 to 1.5 and is not of
concern. As previously mentioned, EPA does not have a risk concern for a toddler who
could receive post-application exposure from both dermal exposure (crawling on a
treated lawn immediately after carbaryl application) and from incidental oral exposure
from eating grass treated with carbaryl (residential ARI of 0.92).
Table 12. Summary of Carbaryl Post-application Aggregate Risks to Children
Residential Exposure
Scenario
Dietary ARI
(food + water)
Residential ARI
Aggregate ARI
Children Age 10-12
Thinning Fruit Trees in
Home Orchard
57
5.5 (dermal only)
5.0
Toddler Age 1-2
Playing with Pet wearing
carbaryl collar
Playing on Treated Turf
(dermal only)
Playing on Treated Turf
(dermal + incidental oral
Playing on Treated Turf
(dermal + incidental oral)
33
33
33
33
1.6 (dermal only)
1.3 (dermal only)
1.6 (dermal + hand-to-
mouth)
0.92 (Dermal + object-to-
mouth)
1.5
1.3
1.5
0.9
Chronic Aggregate Risk
As previously mentioned, EPA did not consider chronic risk from carbaryl
exposure due to the rapid reversibility of the toxic effect, cholinesterase inhibition.
Therefore, EPA does not have a concern for chronic aggregate risk. In addition, when the
Agency evaluated chronic aggregate risk for the 2003 carbaryl IRED, risks were below
the level of concern.
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4. Poisoning Incident Data for Carbaryl
The Agency reviewed available sources of human incident data for incidents
relevant to carbaryl. The following sources were used: 1) The Office of Pesticide
Programs' (OPP) Incident Data System (IDS), comprised of reports of adverse effects
submitted by registrants, other federal and state health and environmental agencies and
the public through FIFRA 6(a)2 since 1992; 2) California Department of Pesticide
Regulation's pesticide poisoning surveillance program, comprised of reports from
physicians of illness suspected of being related to pesticide exposure since 1982; 3)
National Institutes of Occupational Safety and Health (NIOSH) Sentinal Event
Notification System for Occupational Risks (SENSOR), which provides surveillance in
seven states from 1998 through 2003; and 4) Poison Control Center (PCC) data covering
the years 1993 through 2005 for all pesticides. Symptoms captured in these reports
ranged from nervous/sensory (headache, confusion, and dizziness), gastrointestinal
(nausea), respiratory (pain/irritation, shortness of breath, irritation), ocular symptoms
(eye pain/irritation/ inflammation, and lacrimation), dermal symptoms (erythema, rash,
and pruritis), and miscellaneous (alkalosis). EPA's review of the human incident data for
carbaryl can be found in the September 21, 2007, Review of Carbaryl Incident Reports.
The Incident Data System reported 160 cases for carbaryl between the years 2000
and 2006. Of these, nearly 20 cases were the results of misuse (15) or suicide attempts
(4). The California Pesticide Illness Surveillance Program (PISP, 2000-2005) reported
11 cases for carbaryl. In 6 of these cases, carbaryl was used alone or was judged to be
responsible for the health effects. The NIOSH SENSOR database reports only 75 cases
involving carbaryl alone (of 5,899 reported cases of pesticide poisonings from 1998 to
2003).
The Poison Control Center (PCC) Data from 1993 to 2005 show that of a total of
10,781 exposure cases to children from all pesticides, 4,030 cases were from exposure to
carbaryl. However, in 2003 EPA initiated a data call-in (DCI) for carbaryl which resulted
in the voluntary cancellation of more than 200 carbaryl products, many of which were
registered for use in and around the home environment. As a result of the 2003 IRED,
EPA implemented action to cancel numerous carbaryl products, including all pet uses and
all carbaryl aerosol products. Therefore, EPA performed additional analyses to
determine which products were associated with incidents in the recent years (2003-2005).
The data show that 75% the health care facility reported incidents for non-occupational
exposures are due to carbaryl products that are now cancelled. As these products become
unavailable as existing stocks are depleted, the Agency anticipates these carbaryl
incidents will continue to decline.
Since the IRED was issued in 2003, approximately 35% of the residential use
carbaryl products have been cancelled and significant mitigation designed to reduce
exposures have been applied to residential use carbaryl products. EPA believes that these
mitigation measures have addressed the root cause of many of the incidents reported.
The Agency will continue to monitor the incident reports as mitigation measures are
incorporated onto product labels and will impose additional mitigation as needed.
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III. Risk Management, Reregistration Eligibility, and Tolerance Reassessment
A. Determination of Reregistration Eligibility
Section 4(g)(2)(A) of FIFRA calls for the Agency to determine, after submission
of relevant data concerning an active ingredient, whether or not products containing the
active ingredient are eligible for reregi strati on. The Agency has previously identified and
required the submission of the generic (technical or manufacturing-use grade) data
required to support reregi strati on of products containing carbaryl as an active ingredient.
EPA has completed its review of submitted data and its assessment of the dietary,
residential, occupational, and ecological risks associated with the use of pesticide
products containing the active ingredient carbaryl. In addition, the Agency has re-
evaluated the human health risks associated with all remaining registered uses and
completed the cumulative risk assessment for the N-methyl carbamate group of
pesticides.
Based on the carbaryl data, the revised human health risk assessment, and the N-
methyl carbamate cumulative risk assessment, the Agency has sufficient information on
the human health and ecological effects of carbaryl to complete its tolerance reassessment
process under FFDCA and the reregi strati on process under FIFRA, as amended by
FQPA. EPA has determined that remaining products containing carbaryl will be eligible
for reregi strati on provided that: (i) the risk mitigation measures outlined in this
document and in the October 22, 2004 Carbaryl IRED amendment are adopted; and (ii)
all remaining carbaryl product labels are amended to reflect these measures. At this time,
the Agency is requiring additional mitigation for granular turf products for residential
use; product labels must be amended to require that the product be watered in
immediately after application. Because most granular turf product labels currently
recommend that the product be watered in, and because this is necessary for efficacy for
soil-borne insect pests, the Agency does not believe this should pose an unreasonable
burden on homeowners.
Based on the evaluation of carbaryl described in this document and in the October
2004 carbaryl IRED amendment, the Agency has determined that carbaryl products,
unless labeled and used as specified in this document and the October 22, 2004 IRED
amendment, would present risks inconsistent with FIFRA and FFDCA. Accordingly,
should a registrant fail to implement any of the risk mitigation measures identified in this
document, and the October 2004 IRED amendment, the Agency may take regulatory
action to address the risk concerns from the use of carbaryl. If all changes outlined in this
document and in the 2004 carbaryl IRED amendment are incorporated into the product
labels, then all current risks for carbaryl will be adequately mitigated for the purposes of
this determination under FIFRA.
If the Agency determines that any aspect of the reregi strati on and tolerance
reassessment decisions described in this document and in the October 22, 2004 carbaryl
IRED amendment are no longer appropriate, then EPA will pursue appropriate action,
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including but not limited to reconsideration of any portion of this RED decision. The
Agency is currently revisiting the revised occupational risk assessment, which does not
identify any additional risk concerns, and will amend this RED to incorporate any
resulting changes in the regulatory decision. In addition, as a separate action, EPA is
preparing a response to petitions to cancel all uses of carbaryl and revoke all carbaryl
tolerances. The Agency's response to these petitions will be released at a later date.
B. Food Quality Protection Act Findings
The Agency has evaluated the human health risks associated with all currently
registered uses of carbaryl and has 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 has considered dietary exposure from food
and drinking water and all other non-occupational sources of pesticide exposure for
which there is reliable information. The Agency has concluded that with the adoption of
the risk mitigation measures identified in the N-methyl carbamate cumulative risk
assessment, all of the tolerances for carbaryl and the other N-methyl carbamates 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 are
now considered reassessed as safe under section 408(q) of FFDCA, as amended by
FQPA. The basis for EPA's safety finding and the carbaryl tolerance reassessment
summary are described herein.
1. "Risk Cup" Determination
As part of the FQPA tolerance reassessment process, EPA assessed the risks
associated with carbaryl. The Agency has determined that human health risks as a result
of exposures to carbaryl are within acceptable levels. In other words, EPA has concluded
that all of the tolerances for carbaryl meet FQPA safety standards. In reaching this
determination, EPA has considered the available information on the special sensitivity of
infants and children, as well as exposures to carbaryl from all possible sources. Because
carbaryl is a member of the N-methyl carbamate class of pesticides, which share a
common mechanism of toxicity, EPA has conducted a cumulative risk assessment to
evaluate exposures and risks resulting from all registered uses of N-methyl carbamate
pesticides, including carbaryl. EPA has concluded that the cumulative risks associated
with the N-methyl carbamate pesticides meet the safety standard set forth in section
408(b)(2) of the FFDCA. EPA is thereby terminating the tolerance reassessment process
under 408(q) of the FFDCA. For additional information, refer to the document, Revised
N-methyl Carbamate Cumulative Risk Assessment, which is available in the EPA docket
EPA-HQ-OPP-2007-093 5 and on the web, http://www.epa.gov/pesticides/cumulative/.
2. Determination of Safety to U.S. Population
The Agency has determined that the established tolerances for carbaryl meet the
safety standards under the FQPA amendments to section 408(b)(2)(D) of the FFDCA,
and that there is a reasonable certainty no harm will result to the general population or
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any subgroup from the use of carbaryl. In reaching this conclusion, the Agency has
considered all available information on the toxicity, use practices and exposure scenarios,
and the environmental behavior of carbaryl. As discussed in section II of this document,
the aggregate risks from carbaryl from food, drinking water, and residential exposure are
not of concern.
3. Determination of Safety to Infants and Children
EPA has determined that the established tolerances for carbaryl, with amendments
and changes as specified in this document, meet the safety standards under the FQPA
amendments to section 408(b)(2)(C) of the FFDCA, that there is a reasonable certainty of
no harm for infants and children. The safety determination for infants and children
considers the toxicity, use practices, and environmental behavior for the general
population, but also takes into account the possibility of increased dietary exposure due to
the specific consumption patterns of infants and children, as well as the possibility of
increased susceptibility to the toxic effects of carbaryl residues in this population
subgroup.
In determining whether or not infants and children are particularly susceptible to
toxic effects from exposure to residues of carbaryl, the Agency considered the
completeness of the hazard database for developmental and reproductive effects, the
nature of the effects observed, and other information. As previously mentioned, EPA
received a comparative cholinesterase study for carbaryl in November 2006 to inform the
FQPA safety factor decision. A new FQPA safety factor was derived from the
comparative cholinesterase study data by comparing the BMDio for brain cholinesterase
inhibition between adults and pups at postnatal day 11. Because these pups were 1.8x as
sensitive to cholinesterase inhibition as the adults, the FQPA safety factor was set at 1.8x,
and applied to both the N-methyl carbamate cumulative and the carbaryl-specific risk
assessments. This safety factor is applied to the dermal endpoint because the endpoint
was selected from a dermal toxicity study, because there are no comparative
cholinesterase data in offspring from dermal exposure, and because juvenile rats are 1.8x
more sensitive than adults based on the oral comparative cholinesterase study in rats.
However, the FQPA safety factor is reduced to Ix for oral and inhalation endpoints
because these endpoints are selected from the comparative cholinesterase data for the
most sensitive population (postnatal day 11 pups).
4. Endocrine Disrupter Effects
EPA is required under the FFDCA, as amended by FQPA, to develop a screening
program to determine whether certain substances (including all pesticide active and other
ingredients) "may have an effect in humans that is similar to an effect produced by a
naturally occurring estrogen, or other endocrine effects as the Administrator may
designate." Following recommendations of its Endocrine Disrupter Screening and
Testing Advisory Committee (EDSTAC), EPA determined that there was a scientific
basis for including, as part of the program, the androgen and thyroid hormone systems, in
addition to the estrogen hormone system. EPA also adopted EDSTAC's recommendation
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that the Agency include evaluations of potential effects in wildlife. When additional
appropriate screening and/or testing protocols being considered under the Agency's
EDSP have been developed, carbaryl may be subjected to further screening and/or testing
to better characterize effects related to endocrine disruption.
5. Cumulative Risks
Section 408(b)(2)(D)(v) of FFDCA requires that, when considering whether to
establish, modify, or revoke a tolerance, the Agency consider "available information"
concerning the cumulative effects of a particular pesticide's residues and "other
substances that have a common mechanism of toxicity." Other substances are considered
to account for the possibility that low-level exposures to multiple chemical substances
that cause a common effect by a common mechanism could lead to the same adverse
health effect as would a higher level of exposure to each individual substance.
Carbaryl is a member of the N-methyl carbamate class of pesticides, which share
a common mechanism of toxicity by affecting the nervous system via cholinesterase
inhibition. 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 N-
methyl carbamate pesticides, including carbaryl. EPA has concluded that the cumulative
risks associated with the N-methyl carbamate pesticides meet the safety standard set forth
in section 408(b)(2) of the FFDCA. EPA is thereby terminating the tolerance
reassessment process under 408(q) of the FFDCA. For additional information, refer to
the document, Revised N-methyl Carbamate Cumulative Risk Assessment, which is
available in the EPA docket EPA-HQ-OPP-2007-0935 and on the website,
http://www.epa.gov/pesticides/cumulative/.
C. Tolerance Reassessment Summary
Tolerances for residues of carbaryl in/on plant commodities [40 CFR §180.169]
are presently expressed in terms of the combined residues of carbaryl (1-napthyl TV-
methyl carbamate), including its hydrolysis product 1-napthol, calculated as 1-napthyl 7V-
methylcarbamate. The tolerance expression for carbaryl in/on plant commodities should
be modified to include only the parent compound. Tolerances for residues of carbaryl in
livestock commodities (meat and milk) are presently expressed as the combined residues
of carbaryl (1-napthyl TV-methyl carbamate) and its metabolites: 1-napthol (napthyl
sulfate); 5,6-dihydrodihydroxycarbaryl; and 5,6-dihydrodihydroxy napthol, calculated as
1-napthyl TV-methyl carbamate. The tolerance expression for livestock commodities
should be amended to also include free and conjugated residues of carbaryl: 5,6-dihydro-
5,6-dihydroxy carbaryl, and 5-methoxy-6-hydroxy carbaryl
The Agency's tolerance summary is provided in Table 13. EPA considered 120
of the carbaryl tolerances to be reassessed on June 29, 2006, because these tolerances
cover commodities that are not significant contributors to the N-methyl carbmate
cumulative risk assessment. Because EPA has now completed and released the
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cumulative risk assessment for the N-methyl carbamates, the remaining 11 carbaryl
tolerances are considered reassessed at this time. Table 13 lists several tolerances
associated with uses that are no longer registered, as announced in several FIFRA 6(f)(l)
Notices of Receipt of Requests from the registrant for cancellation and/or use deletion.
Because EPA approved these requests for cancellation or use deletion, the associated
tolerances should be revoked, except for the wheat tolerance, which is still needed to
cover imported wheat and any domestic wheat that may receive inadvertent residues of
carbaryl resulting from carbaryl use to control grasshoppers and/or Mormon crickets on
pasture and rangeland. (The Agency has included carbaryl residues on wheat in the
cumulative risk assessment for the N-methyl carbamates.)
Many existing carbaryl tolerances will be reassigned to crop groups, and these
tolerances will be revoked as new tolerances are established for residues in/on various
crop groups and subgroups. New tolerances need to be established for carbaryl residues
in/on the following raw agricultural commodities: aspirated grain fractions, proso millet
hay, sorghum stover, and sugar beet roots. At the present time, sufficient data are only
available to determine an appropriate tolerance for residues in/on aspirated grain fractions
(70 ppm), sugar beet roots (0.5 ppm), and sorghum stover (30.0 ppm). Additional residue
data are required before appropriate tolerances can be determined for residues in/on proso
millet hay. Separate tolerances also need to be established for residues in the following
processed food/feed items: wet apple pomace (15.0 ppm), citrus fruit oil (20.0 ppm),
raisins (12.0 ppm), and rice hulls (30.0 ppm). The Agency will commence rulemaking
proceedings to revoke and modify the existing tolerances, and correct commodity
definitions.
Table 13. Tolerance Reassessment Summary Table for Carbaryl
Commodity
Current Tolerance
(ppm)
Tolerance
Reassessment (ppm)
Comments
[Correct Commodity Definition]
Tolerance Listed Under 40 CFR §180.169(a)(l)
Raw Agricultural Commodities
Alfalfa*
Alfalfa, hay*
Almond*
Almond, hulls*
Apricot
Asparagus*
Banana*
100
100
1
40
10
10
10
50
75
Reassign
50
Reassign
15
5
Residue data indicate tolerance should be
lowered to 50 ppm. [alfalfa, forage]
Residue data indicate that the tolerance
should be lowered to 75 ppm.
Tolerance should be reassigned concomitant
with establishing a 0. 1 ppm tolerance on
[nut, tree, group 14, except walnut].
Residue data indicate tolerance should be
increased to 50 ppm.
Tolerance should be reassigned concomitant
with establishing a 10 ppm tolerance on
[fruit, stone, group 12].
Residue data indicate that the tolerance
should be increased to 15 ppm.
Residue data indicate that the tolerance
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Commodity
Bean
Bean, forage
Bean, hay
Beet, garden,
roots*
Beet, garden,
tops*
Beet, sugar, tops*
Blackberry*
Blueberry*
Boysenberry*
Broccoli*
Brussels sprouts*
Cabbage*
Cabbage,
Chinese*
Carrot, roots*
Current Tolerance
(ppm)
10
100
100
5
12
100
12
10
12
10
10
10
10
10
Tolerance
Reassessment (ppm)
Reassign
Revoke
Reassign
Reassign
25
Reassign
Reassign
Reassign
10
10
21
Reassign
Reassign
Comments
[Correct Commodity Definition]
should be lowered to 5 ppm.
Tolerance should be reassigned concomitant
with establishing a 10 ppm tolerance for
[vegetable, legume, edible-podded, subgroup
6 A], and a 1.0 ppm tolerance for [pea and
bean, dried shelled, except soybean,
subgroup 6CJ.
Tolerance should be revoked. Bean forage
and hay are no longer considered significant
livestock feed items.
Tolerance should be reassigned concomitant
with establishing a 2 ppm tolerance on the
[vegetable, root and tuber, group 1, except
sugar beet and sweet potato].
Tolerance should be reassigned concomitant
with establishing a 75 ppm tolerance on the
[vegetable, leaves of root and tuber, group 2,
except sugar beet tops].
Residue data indicate that the tolerance
should be lowered to 25 ppm.
Tolerance should be reassigned concomitant
with establishing a 12 ppm tolerance on the
[caneberry subgroup 13AJ.
Tolerance should be reassigned concomitant
with establishing a 3 ppm tolerance on the
[bushberry subgroup 13BJ.
Tolerance should be reassigned concomitant
with establishing a 12 ppm tolerance on the
[caneberry subgroup 13AJ.
[vegetable, brassica, leafy, group 5, except
cabbage].
Residue data on broccoli translates to
Brussels sprouts, [vegetable, brassica, leafy,
group 5, except cabbage].
Residue data indicate that tolerance should be
increased to 21 ppm.
Tolerance should be reassigned concomitant
with establishing a 10 ppm tolerance on the
[vegetable, brassica, leafy, group 5, except
cabbage].
Tolerance should be reassigned concomitant
with establishing a 2 ppm tolerance on the
[vegetables, root and tuber, group 1, except
sugar beet and sweet potato]', considered
reassessed on June 29, 2006.
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Commodity
Cauliflower*
Celery*
Cherry
Chestnut*
Clover*
Clover, hay*
Collards*
Corn, sweet kernal
plus cob with
husks removed *
Corn, stover*
Corn, forage*
Cottonseed,
undelinted seed*
Cowpea*
Current Tolerance
(ppm)
10
10
10
1
100
100
12
5
100
100
5
5
Tolerance
Reassessment (ppm)
10
Reassign
Reassign
Reassign
50
70
Reassign
0.1
0.02
20
215
30
185
Revoke
Reassign
Comments
[Correct Commodity Definition]
Data on broccoli translates to cauliflower.
[vegetable, brassica, leafy, group 5, except
cabbage].
Tolerance should be reassigned concomitant
with establishing a 3 ppm tolerance on the
[leaf petioles subgroup 4BJ.
Tolerance should be reassigned concomitant
with establishing a 10 ppm tolerance on the
[fruit, stone, group 12].
Tolerance should be reassigned concomitant
with establishing a 0. 1 ppm tolerance on
[nut, tree, group 14, except walnut].
Residue data indicate that the tolerance
should be lowered to 50 ppm. [clover,
forage].
Residue data indicate that the tolerance
should be lowered to 70 ppm.
Tolerance should be reassigned concomitant
with establishing a 10 ppm tolerance on the
[vegetable, brassica, leafy, group 5, except
cabbage].
Residue data indicate that a separate
tolerance on sweet corn should be established
at 0.1 ppm [corn, sweet, kernel plus cob with
husks removed].
Residue data indicate that a separate
tolerance should be established for corn,
grain at 0.02 ppm [corn, field, grain] and
[corn, pop, grain].
Residue data indicate that the tolerance for
field and pop corn stover should be lowered
to 20 ppm. [corn, field, stover] and [corn,
pop, stover].
Residue data indicate that the tolerance for
sweet corn stover should be increased, to 215
ppm. [Corn, sweet, stover].
Residue data indicate that the tolerance for
field corn forage should be lowered to 30
ppm. [Corn, field, forage].
Residue data indicate that the tolerance for
field corn forage should be increased to 185
ppm. [Corn, sweet, forage].
Use on cotton has been cancelled; therefore,
the tolerance is no longer needed.
Tolerance should be reassigned concomitant
34
-------
Commodity
Cowpea, forage*
Cowpea, hay*
Cranberry*
Cucumber*
Dandelion leaves*
Dewberry*
Eggplant*
Endive*
Filbert
(hazelnuts)*
Flax, seed*
Fruit, citrus
Grape
Grass*
Grass, hay*
Horseradish*
Kale*
Kohlrabi*
Current Tolerance
(ppm)
100
100
10
10
12
12
10
10
1
5
10
10
100
100
5
12
10
Tolerance
Reassessment (ppm)
Reassign
3
Reassign
22
Reassign
Reassign
10
Reassign
0.5
10
10
100
15
Reassign
Reassign
10
Comments
[Correct Commodity Definition]
with establishing a 1 ppm tolerance for [pea
and bean, dried shelled, except soybean
group 6CJ.
Tolerances should be reassigned concomitant
with establishing a 60 ppm tolerance for
[vegetable, foliage of legume, group 7].
Residue data indicate that the tolerance
should be lowered to 3 ppm.
Tolerance should be reassigned concomitant
with establishing a 3 ppm tolerance on the
[vegetable, cucurbit, group 9].
Residue data on spinach translated to
dandelion, indicate that tolerance should be
increased to 22 ppm. [dandelion, leaves].
Tolerance should be reassigned concomitant
with establishing a 12 ppm tolerance on the
[caneberry subgroup 13AJ.
Tolerance should be reassigned concomitant
with establishing a 5 ppm tolerance on the
[vegetable, fruiting, group 8]
Residue data on lettuce may be translated to
endive, [endive]
Tolerance should be reassigned concomitant
with establishing a 0. 1 ppm tolerance on the
[nut, tree, group 14, except walnut].
Residue data indicate that the tolerance
should be lowered to 0.5 ppm.
[Fruit, citrus, group 10]
Residue data on rangeland grass forage
harvested at a 0-day PGI support the current
tolerance of 100 ppm. [Grass, forage].
Residue data on pasture hay indicate that the
tolerance should be lowered to 15 ppm.
Tolerance should be reassigned concomitant
with establishing a 2 ppm tolerance on the
[vegetable, root and tuber, group 1, except
sugar beet and sweet potato] .
Tolerance should be reassigned concomitant
with establishing a 10 ppm tolerance on the
[vegetable, brassica, leafy, group 5, except
cabbage].
Residue data on broccoli translates to
kohlrabi, [brassica, leafy, group 5, except
35
-------
Commodity
Lentil, seed*
Lettuce*
Loganberry*
Melon*
Millet, proso,
grain*
Millet, proso,
straw*
Mustard greens*
Nectarine
Okra*
Olive*
Oyster*
Parsley, leaves*
Parsnip*
Peach
Peanut*
Peanut, hay*
Current Tolerance
(ppm)
10
10
12
10
3
100
12
10
10
10
0.25
12
5
10
5
100
Tolerance
Reassessment (ppm)
Reassign
10
Reassign
Reassign
1
20
Reassign
Reassign
4
10
0.25
22
Reassign
Reassign
0.05
20
Comments
[Correct Commodity Definition]
cabbage]
Tolerance should be reassigned concomitant
with establishing a 1 ppm tolerance on the
[pea and bean, dried shelled, except soybean
group 6CJ.
Tolerance should be reassigned concomitant
with establishing a 12 ppm tolerance on the
[caneberry subgroup 13 A].
Tolerance should be reassigned concomitant
with establishing a 3 ppm tolerance on the
[vegetable, cucurbit, group 9J.
Residue data for wheat grain indicate that the
tolerance should be lowered to 1 ppm. Data
for wheat grain translates to millet.
Residue data on wheat straw indicate that the
tolerance should be lowered to 20 ppm. Data
for wheat straw translates to millet straw.
Tolerance should be reassigned concomitant
with establishing a 10 ppm tolerance on the
[vegetable, brassica, leafy, group 5, except
cabbage].
Tolerance should be reassigned concomitant
with establishing a 10 ppm tolerance on the
[fruit, stone, group 12].
The available data indicate that the tolerance
should be lowered to 4 ppm.
Available residue data on spinach indicate
that the tolerance on parsley should be
increased to 22 ppm. Spinach data translates
to parsley. [Parsley, leaves]
Tolerance should be reassigned concomitant
with establishing a 2 ppm tolerance on the
[vegetable, root and tuber, group 1, except
sugar beet and sweet potato].
Tolerance should be reassigned concomitant
with establishing a 10 ppm tolerance on the
[fruit, stone, group 12].
Residue data indicate that the tolerance
should be lowered to 0.05 ppm.
Residue data indicate that the tolerance
should be lowered to 20 ppm.
36
-------
Commodity
Pea (with pods)*
Pea, field, vines*
Pecan*
Pepper
Pistachio*
Plum, prune, fresh
Poultry, fat
Poultry, meat
Potato*
Prickly pear
cactus, fruit*
Prickly pear
cactus, pads*
Pumpkin*
Radish*
Raspberry*
Rice, grain*
Rice, straw*
Current Tolerance
(ppm)
10
100
1
10
1
10
5
5
0.2(N)
12
12
10
5
12
5
100
Tolerance
Reassessment (ppm)
Reassign
Reassign
Reassign
Reassign
0.1
Reassign
Revoke
Revoke
Reassign
5
12
Reassign
Reassign
Reassign
15
60
Comments
[Correct Commodity Definition]
Tolerance should be reassigned concomitant
with establishing a 10 ppm tolerance for
[vegetable, legume, edible podded, subgroup
6AJ.
Tolerance should be reassigned concomitant
with establishing a 60 ppm tolerance for the
[vegetable, foliage of legume, group 7].
Tolerance should be reassigned concomitant
with establishing a 0. 1 ppm tolerance on the
[nut, tree, group 14, except walnut].
Tolerance should be reassigned concomitant
with establishing a 5 ppm tolerance on the
[vegetable, fruiting, group 8].
Residue data indicate that the pistachio
tolerance should be lowered to 0.1 ppm.
[pistachio]
Tolerance should be reassigned concomitant
with establishing a 10 ppm tolerance on the
[fruit, stone, group 12].
Poultry tolerances are no longer needed
because there is no reasonable expectation of
finite residues. Also, the direct use on
poultry and in poultry houses has been
cancelled.
Tolerance should be reassigned concomitant
with establishing a 2 ppm tolerance on the
[vegetable, root and tuber, group 1, except
sugar beet and sweet potato] .
Residue data indicate that the tolerance
should be lowered to 5 ppm. [cactus, fruit]
[cactus, pads]
Tolerance should be reassigned concomitant
with establishing a 3 ppm tolerance on the
[vegetable, cucurbit, group 9].
Tolerance should be reassigned concomitant
with establishing a 2 ppm tolerance on the
[vegetable, root and tuber, group 1, except
sugar beet and sweet potato].
Tolerance should be reassigned concomitant
with establishing a 12 ppm tolerance on the
[caneberry subgroup 13AJ.
Residue data indicate that the tolerance
should be increased to 15 ppm. [Rice, grain]
Residue data indicate that the tolerance
37
-------
Commodity
Rutabagas*
Salsify (roots)*
Salsify, tops*
Sorghum, forage*
Sorghum, grain*
Soybean*
Soybean, forage*
Soybean, hay*
Spinach*
Squash, summer*
Squash, winter*
Strawberry
Sunflower, seed*
Sweet potato,
roots*
Swiss chard*
Tomato*
Trefoil, forage*
Current Tolerance
(ppm)
5
5
10
100
10
5
100
100
12
10
10
10
1
0.2
12
10
100
Tolerance
Reassessment (ppm)
Reassign
Reassign
Reassign
30
10
0.5
15
15
22
Reassign
4
0.5
0.2
Reassign
Reassign
15
Comments
[Correct Commodity Definition]
should be lowered to 60 ppm.
Tolerance should be reassigned concomitant
with establishing a 2 ppm tolerance on the
[vegetable, root and tuber, group 1, except
sugar beet and sweet potato].
Tolerance should be reassigned concomitant
with establishing a 2 ppm tolerance on the
[vegetable, root and tuber, group 1, except
sugar beet tops].
Tolerance should be reassigned concomitant
with establishing a 75 ppm tolerance on the
[vegetable, leaves of root and tuber, group 2,
except beet, sugar, tops].
Residue data indicate that tolerance should be
lowered to 30 ppm [sorghum, grain, forage]
[Sorghum, grain, grain]
Residue data indicate that the tolerance
should be lowered to 0.5 ppm. [Soybean,
seed]
Residue data indicate that the tolerance
should be lowered to 15 ppm.
Residue data indicate that the tolerance
should be lowered to 15 ppm.
Residue data on spinach indicate that the
tolerance should be increased to 22 ppm.
Tolerances should be reassigned concomitant
with establishing a 3 ppm tolerance on the
[vegetable, cucurbit, group 9].
Residue data indicate that the tolerance
should be lowered to 4 ppm.
Residue data indicate that tolerance should be
lowered to 0.5 ppm.
[Sweet potato, roots]
Tolerance should be reassigned concomitant
with establishing a 3 ppm tolerance on the
[leaf petioles subgroup 4B].
Tolerance should be reassigned concomitant
with establishing a 5 ppm tolerance on the
[vegetable, fruiting, group 8J.
Residue data on alfalfa forage translates to
[trefoil, forage] and indicates that the
tolerance should be lowered to 15 ppm.
38
-------
Commodity
Trefoil, hay*
Turnip, roots*
Turnip, greens*
Walnut*
Wheat, grain*
Wheat, hay
Wheat, straw
Current Tolerance
(ppm)
100
5
12
1
3
100
100
Tolerance
Reassessment (ppm)
25
Reassign
Reassign
1
1
100
100
Comments
[Correct Commodity Definition]
Residue data on alfalfa hay translates to
[trefoil, hay] and indicates that the tolerance
should be lowered to 25 ppm.
Tolerance should be reassigned concomitant
with establishing a 2 ppm tolerance on the
[vegetable, root and tuber, group 1, except
sugar beet and sweet potato].
Tolerance should be reassigned concomitant
with establishing a 75 ppm tolerance on the
[vegetable, leaves of root and tuber, group 2,
except sugar beet tops].
Residue data indicate that the tolerance
should be lowered to 1 ppm.
Tolerances Listed Under 40 CFR §180.169(a)(2)
Livestock Commodities
Cattle, fat
Cattle, kidney
Cattle, liver
Cattle, meat
Cattle, meat
byproducts
Goat, fat*
Goat, kidney*
Goat, liver*
Goat, meat*
Goat, meat
byproducts*
Horse, fat*
Horse, kidney
Horse, liver
0.1
1
1
0.1
0.1
0.1
1
1
0.1
0.1
0.1
1
1
0.5
Reassign
1
3
0.5
Reassign
1
3
0.5
Reassign
Reassign
Residue data indicate that the tolerance
should be increased to 0.5 ppm.
Tolerance should be increased to 3 ppm and
reassigned to [cattle, meat byproducts].
Residue data indicate that the tolerance
should be increased to 1 ppm.
Residue data indicate that the tolerance
should be increased to 3 ppm. Reassessed
tolerance should include kidney and liver.
Residue data indicate that the tolerance
should be increased to 0.5 ppm.
Tolerance should be increased to 3 ppm and
reassigned to [goat, meat byproducts].
Residue data indicate that the tolerance
should be increased to 1 ppm.
Residue data indicate that the tolerance
should be increased to 3 ppm. Reassessed
tolerance should include kidney and liver.
Residue data indicate that the tolerance
should be increased to 0. 5 ppm.
Tolerance should be increased to 3 ppm and
reassigned to [horse, meat byproducts].
39
-------
Commodity
Horse, meat
Horse, meat
byproducts
Sheep, fat*
Sheep, kidney*
Sheep, liver*
Sheep, meat*
Sheep, meat
byproducts*
Swine, fat*
Swine, kidney*
Swine, liver*
Swine, meat*
Swine, meat
byproducts*
Current Tolerance
(ppm)
0.1
0.1
0.1
1
1
0.1
0.1
0.1
1
1
0.1
0.1
Tolerance
Reassessment (ppm)
1
3
0.5
Reassign
1
3
0.05
Reassign
0.1
0.5
Comments
[Correct Commodity Definition]
Residue data indicate that the tolerance
should be increased to 1 ppm.
Residue data indicate that the tolerance
should be increased to 3 ppm. Reassessed
tolerance should include kidney and liver.
Residue data indicate that the tolerance
should be increased to 0.5 ppm.
Residue data indicate that the tolerance
should be increased to 3 ppm and reassigned
to [sheep, meat byproducts].
Residue data indicate that the tolerance
should be increased to 1 ppm.
Residue data indicate that the tolerance
should be increased to 3 ppm. Reassessed
tolerance should include kidney and liver.
Residue data indicate that the tolerance
should be lowered to 0.05 ppm. [hog, fat]
Tolerance should be lowered to 0.5 ppm and
reassigned to [hog, meat byproducts].
[hog, meat]
Reassessed tolerance should include kidney
and liver, [hog, meat byproducts]
Tolerance Listed Under 40 CFR §180.169(a)(3)
Milk and Eggs
Milk*
0.3
1.0
Tolerance should be moved to 40 CFR
§180.169(a)(2).
Tolerance Listed Under 40 CFR §180.169(a)(4)
Fruit, pome
Pineapple
10
2
12
TBD2
Residue data indicate that the tolerance
should be increased to 12 ppm. Tolerance
should be moved to 40 CFR §180.169(a)(l).
[fruit, pome, group 1 1]
Residue data are required. Tolerance should
be moved to 40 CFR §180.169(a)(l).
Tolerance Listed Under 40 CFR §180.169(c)
Regional Registrations
Dill, fresh*
0.2
0.2
[dilhveed, fresh leaves]
Interim Tolerance Listed Under 40 CFR §180.319
Egg
0.5
Revoke
Tolerance no longer needed because there is
no reasonable expectation of finite residues.
40
-------
Commodity
Current Tolerance
(ppm)
Tolerance
Reassessment (ppm)
Comments
[Correct Commodity Definition]
Tolerances to be Established Under 40 CFR §180.169(a)(l)
Raw Agricultural Commodities
Apple, wet
pomace
Grain, aspirated
fractions
Beet, sugar, roots
Citrus, oil
Grape, raisin
Millet, proso, hay
Rice, hulls
Sorghum, grain,
stover
None
None
None
None
None
None
None
None
15
70
0.5
20
12
TBD2
30
30
Residue data support establishing a 15 ppm
tolerance on wet apple pomace, [apple, wet
pomace]
Residue data indicate that a tolerance of 70
ppm should be established for residues in/on
aspirated grain fractions, [grain, aspirated
fractions]
The available data indicate that a tolerance of
0.5 ppm should be established for residues
in/on sugar beet roots, [beets, sugar, roots]
Residue data support establishing a 20 ppm
tolerance on citrus fruit oil. [citrus, oil]
Residue data support establishing a 12 ppm
tolerance on raisin, [grape, raisin]
Residue data are required.
Residue data support establishing a 30 ppm
tolerance for residues in/on rice hulls.
Residue data support establishing a 30 ppm
on [sorghum grain, stover].
* Considered reassessed on June 29, 2006 because associated commodity is not a significant contributor to
cumulative risk from the N-methyl carbamates. TBD, to be determined pending completion of outstanding
residue studies required in the March 2005 generic DCI for carbaryl. Pineapple tolerance will be
determined pending review of field trial data (OPPTS Guideline 860.1500). Proso millet hay tolerance
will be determined pending receipt of field trials for wheat hay, which will be translated to millet (OPPTS
Guideline 860.1500).
41
-------
Technical Support Documents for Carbaryl
Human Health Effects
FortF. 2007b. CARBARYL. HED Chapter of the Reregistration Eligibility Decision
Document (RED). June 29, 2007.
Reaves E. 2007. Carbaryl: Updated Endpoint Selection for Single Chemical Risk
Assessment. June 29, 2007.
ShahPV. 2007. Carbaryl: Review of in vitro Dermal Absorption Study (MRID
47151902). June 28, 2007.
Moser G. 2007. Report on Comparative Sensitivity Study of Carbaryl. MRID
47143001. May 7, 2007.
USEPA, 2000. Benchmark Dose Technical Guidance Document. Draft report. Risk
Assessment Forum, Office of Research and Development, U.S. Environmental
Protection Agency. Washington, DC. EPA/630/R-00/001
Fort F. 2007a. Carbaryl Acute Probabilistic Aggregate Dietary (Food and Drinking
Water) Exposure and Risk Assessment for the Reregistration Eligibility Decision.
June 27, 2007.
Britton W. 2007a. Carbaryl: Revisions to Residential Exposure and Risk
Assessment. June 29, 2007.
Britton W. 2007b. Carbaryl: Addendum to the "HED Chapter of the Reregistration
Eligibility Decision Document (RED). " September 21, 2007.
Tadayon S. 2006. [Review of] Transferable residues from dogs treated with 16%
carbaryl collar, MRIDS 45792201, 46015001, and4607560. December 5, 2006.
Allen R, Hawkins M, Allender H, and Christensen, C. 2007. Review of Carbaryl
Incident Report. September 21, 2007.
Environmental Fate and Drinking Water
Behl B. 2003. Review of "Surface Water Monitoring for Residue of Carbaryl in
High Use Areas in the United States: Final Report. " September 22, 2003
Behl B. and Young D. 2007. Revised Carbaryl Drinking Water Assessment
Including Time Series Simulations. May 2, 2007.
42
-------
Young D. 2007a. Carbaryl refined drinking water time series simulations using
PCAs. March 9, 2007
Use, Usage, Alternatives, and Benefits
Atwood D. 2007a. Alternatives Assessment for Carbaryl Use on Residential Lawns.
July 13, 2007.
Atwood D. 2007b. Alternatives Assessment for Carbaryl Impregnated Flea and Tick
Collars on Dogs and Cats. September 21, 2007.
Carter J. 2007. Usage Report Package in Support of Reregistration for Carbaryl.
September 6, 2007.
Halvorsen A. 2006. Usage Report for the Insecticide Carbaryl. December 7, 2006.
43
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