United States Prevention, Pesticides EPA-738-R-06-031 

Environmental Protection And Toxic Substances August 2006 

 Agency (7508P) 

 __________________________________________________________

Interim Reregistration 

Eligibility Decision 

Carbofuran

List [A] 

Case No. 0101 
Interim Reregistration Eligibility Decision (IRED) 

Document for Carbofuran

Approved by: Debra Edwards, Ph. D. 

 Director 

 Special Review and Reregistration Division 

Date: August 3, 2006 
Table of Contents 

Carbofuran Interim Reregistration Eligibility Decision Team ............................................ i 

Glossary of Terms and Abbreviations................................................................................ ii 

I. Introduction................................................................................................................. 1 

II. Chemical Overview ................................................................................................ 2 

A. Regulatory History.................................................................................................. 2 

B. Chemical Identification........................................................................................... 3 

C. Use Profile .......................................................................................................... 4 

D. Estimated Usage of Pesticide.................................................................................. 5 

III. Summary of Carbofuran Risk Assessments........................................................... 5 

A. Human Health Risk Assessment............................................................................. 5 

1. Toxicity of Carbofuran ....................................................................................... 5 

2. Dietary Exposure and Risk from Food and Water............................................. 9 

3. Residential and Other Non-occupational Risk.................................................. 12 

4. Aggregate Exposure and Risk........................................................................... 12 

5. Occupational Exposure and Risk...................................................................... 13 

6. Smoker Assessment .......................................................................................... 17 

7. Human Incident Data ........................................................................................ 17 

B. Environmental Risk Assessment........................................................................... 18 

1. Environmental Fate and Transport.................................................................... 20 

2. Ecological Risk Estimation............................................................................... 20 

a. Terrestrial Organisms.................................................................................... 20 

i) Birds.......................................................................................................... 20 

ii) Mammals................................................................................................... 22 

iii) Non-target insects................................................................................. 23 

b. Aquatic Organisms........................................................................................ 24 

i) Freshwater and Estuarine/Marine Fish ..................................................... 25 

ii) Freshwater and Estuarine/Marine Invertebrates ....................................... 26 

3. Risk Characterization........................................................................................ 28 

4. Endangered Species Considerations................................................................. 29 

IV. Interim Risk Management, Reregistration, and Tolerance Reassessment Decision

 29 

A. Determination of Reregistration Eligibility ...................................................... 29 

B. Public Comments and Responses........................................................................ 30 

C. Regulatory Position Under FIFRA and FFDCA................................................... 30 

1. Mitigation Summary ......................................................................................... 31 

2. Regulatory Rationale ........................................................................................ 31 

3. Significance of Use ........................................................................................... 33 

D. Endangered Species Considerations..................................................................... 35 

E. Food Quality Protection Act Findings and Tolerance Summary.......................... 36 

1. FQPA ................................................................................................................ 36 

a. Risk Cup Determination ............................................................................... 36 

b. Endocrine Disruptor Effects ......................................................................... 37 

2. Interim Tolerance Summary ............................................................................. 37 
Carbofuran Interim Reregistration Eligibility Decision Team

Office of Pesticide Programs: 

Biological and Economic Analysis Assessment

David Brassard 

Angel Chiri 

David Donaldson 

Jin Kim 

Andrew Lee 

Stephen Smearman 

TJ Wyatt 

Nicole Zinn 

Environmental Fate and Effects Risk Assessment

Edward Fite 

Edward Odenkirchin 

Melissa Panger 

Donna Randall 

Christopher Salice 

Dirk Young 

Health Effects Risk Assessment

Danette Drew 

John Liccione 

Susan Stanton 

Stephen Weiss 

Registration Support

Rita Kumar 

Risk Management

Stephanie Plummer 

Laura Parsons 

i
Glossary of Terms and Abbreviations 

AGDCI Agricultural Data Call-In 

ai Active Ingredient 

aPAD Acute Population Adjusted Dose 

AR Anticipated Residue 

BCF Bioconcentration Factor 

BMD Benchmark Dose 

CFR Code of Federal Regulations 

cPAD Chronic Population Adjusted Dose 

CSF Confidential Statement of Formula 

CSFII USDA Continuing Surveys for Food Intake by Individuals 

DCI Data Call-In 

DEEM Dietary Exposure Evaluation Model 

EC Emulsifiable Concentrate Formulation 

EDWC Estimated Drinking Water Concentration 

EEC Estimated Environmental Concentration 

EPA Environmental Protection Agency 

EUP End-Use Product 

FCID Food Commodity Intake Database 

FDA Food and Drug Administration 

FIFRA Federal Insecticide, Fungicide, and Rodenticide Act 

FFDCA Federal Food, Drug, and Cosmetic Act 

FQPA Food Quality Protection Act 

FOB Functional Observation Battery 

G Granular Formulation 

GENEEC Tier I Surface Water Computer Model 

GLN Guideline Number 

HAFT Highest Average Field Trial 

IR Index Reservoir 

LC50 Median Lethal Concentration. A statistically derived concentration 

of a substance that can be expected to cause death in 50% of test 

animals. It is usually expressed as the weight of substance per 

weight or volume of water, air or feed, e.g., mg/l, mg/kg or ppm. 

LD50 Median Lethal Dose. A statistically derived single dose that can be 

expected to cause death in 50% of the test animals when 

administered by the route indicated (oral, dermal, inhalation). It is 

expressed as a weight of substance per unit weight of animal, e.g., 

mg/kg. 

LOC Level of Concern 

LOD Limit of Detection 

LOAEL Lowest Observed Adverse Effect Level 

MATC Maximum Acceptable Toxicant Concentration 

Φg/g Micrograms Per Gram 

Φg/L Micrograms Per Liter 

mg/kg/day Milligram Per Kilogram Per Day 

ii
mg/L Milligrams Per Liter 

MOE Margin of Exposure 

MRID Master Record Identification (number). EPA's system of recording 

and tracking studies submitted. 

MUP Manufacturing-Use Product 

NA Not Applicable 

NAWQA USGS National Water Quality Assessment 

NPDES National Pollutant Discharge Elimination System 

NR Not Required 

NOAEL No Observed Adverse Effect Level 

OP Organophosphate 

OPP EPA Office of Pesticide Programs 

OPPTS EPA Office of Prevention, Pesticides and Toxic Substances 

PAD Population Adjusted Dose 

PCA Percent Crop Area 

PDP USDA Pesticide Data Program 

PHED Pesticide Handler's Exposure Data 

PHI Preharvest Interval 

ppb Parts Per Billion 

PPE Personal Protective Equipment 

ppm Parts Per Million 

PRZM/EXAMS Tier II Surface Water Computer Model 

Q1* The Carcinogenic Potential of a Compound, Quantified by the 

EPA's Cancer Risk Model 

RAC Raw Agriculture Commodity 

RED Reregistration Eligibility Decision 

REI Restricted Entry Interval 

RfD Reference Dose 

RQ Risk Quotient 

SCI-GROW Tier I Ground Water Computer Model 

SAP Science Advisory Panel 

SF Safety Factor 

SLC Single Layer Clothing 

SLN Special Local Need (Registrations Under Section 24(c) of FIFRA) 

TAF Toxicity Adjustment Factor 

TCPSA 2,3,3-trichloroprop-2-ene sulfonic acid (nitrapyrin Metabolite) 

TGAI Technical Grade Active Ingredient 

TRR Total Radioactive Residue 

USDA United States Department of Agriculture 

USGS United States Geological Survey 

UF Uncertainty Factor 

UV Ultraviolet 

WPS Worker Protection Standard

iii
I. Introduction

The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) was amended 

in 1988 to accelerate the reregistration of products with active ingredients registered prior 

to November 1, 1984. The amended Act calls for the development and submission of 

data to support the reregistration of an active ingredient, as well as a review of all 

submitted data by the U.S. Environmental Protection Agency (hereafter referred to as 

EPA or the Agency). Reregistration involves a thorough review of the scientific database 

underlying a pesticide's registration. The purpose of the Agency's review is to reassess 

the potential risks arising from the currently registered uses of the pesticide, to determine 

the need for additional data on health and environmental effects, and to determine 

whether or not the pesticide meets the "no unreasonable adverse effects" criteria of 

FIFRA. 

On August 3, 1996, the Food Quality Protection Act of 1996 (FQPA) was signed 

into law. This Act amends FIFRA to require reassessment of all tolerances in effect on 

the day before it was enacted by August 2006. EPA decided that, for those chemicals 

that have tolerances and are undergoing reregistration, tolerance reassessment will be 

accomplished through the reregistration process. FQPA also amended the Federal Food, 

Drug, and Cosmetic Act (FFDCA) to require a safety finding in tolerance reassessment 

based on factors that include an assessment of cumulative effects of chemicals with a 

common mechanism of toxicity. The reason for consideration of other substances is that 

the possibility exists that low-level exposures to multiple chemicals that cause a common 

toxic effect lead to the same adverse health effect as would a high level of exposure to 

any one of the other substances individually. 

As mentioned above, FQPA requires EPA to consider "available information" 

concerning the cumulative effects of a particular pesticide's residues and "other 

substances that have a common mechanism of toxicity" when considering whether to 

establish, modify, or revoke a tolerance. Carbofuran is a member of the N-methyl 

carbamate (NMC) class of pesticides. This class also includes carbaryl, aldicarb, 

methomyl, and oxamyl, among others. The NMCs, as a group, have been determined to 

share a common mechanism of toxicity (July 2001 memo from Office Director Marcia 

Mulkey). The preliminary cumulative risk assessment (CRA) for the NMC cumulative 

Assessment Group, which includes carbofuran, was released in July 2005. The revised 

CRA is currently being developed and will be completed during 2006. The results of this 

NMC cumulative assessment, as well as the single chemical carbofuran assessment, will 

be considered during the carbofuran reregistration process in which decisions regarding 

establishing, modifying, or revoking carbofuran tolerances will be made. 

This document presents EPA’s revised human health and ecological risk assessments 

and its progress toward tolerance reassessment, and the interim reregistration eligibility 

decision for carbofuran. The document consists of six sections: section I contains the 

regulatory framework for reregistration/tolerance reassessment; section II provides a 

profile of the use and usage of the chemical; section III gives an overview of the revised 

1
human health and environmental effects risk assessments based on data, public 

comments, and other information received in response to the preliminary risk 

assessments, section IV presents the Agency’s reregistration eligibility, tolerance 

reassessment, and risk management decisions; section V summarizes label changes 

necessary to implement the risk mitigation measures outlined in Section IV; and section 

VI provides information on how to access related documents. Finally, the Appendices 

list related and supporting documents and Data Call-In (DCI) information. The revised 

risk assessment documents and related addenda are not included in this document, but are 

available in the Public Docket under docket number EPA-HQ-OPP-2005-0162. 

II. Chemical Overview 

 A. Regulatory History 

Carbofuran is a broad spectrum N-methyl carbamate insecticide and nematicide 

registered for control of soil and foliar pests on a variety of field, fruit, and vegetable 

crops. It was first registered in the United States in 1969. Through an agreement 

between EPA and the technical registrant in 1991, granular carbofuran has been limited 

to the sale of 2,500 lbs of active ingredient per year in the U.S. since 1994, for use only 

on certain crops. Today granular carbofuran is limited to use on spinach grown for seed, 

pine seedlings, bananas (in Hawaii only), and cucurbits only. Carbofuran is classified as 

a restricted use pesticide. 

In the late 1990s, the technical registrant made a number of changes to labels in 

order to reduce drinking water and ecological risks of concern. These included reducing 

application rates and numbers of applications for alfalfa, cotton, corn, potatoes, soybeans, 

sugarcane, and sunflowers. Numbers of applications were also restricted on some soils to 

reduce groundwater concentrations. 

Three human studies have been conducted for carbofuran – one oral and two 

dermal. Since the 1990s, the Agency has considered the appropriateness of these studies 

for risk assessment purposes several times. Most recently, these studies were reviewed 

by the Agency’s Human Studies Review Board (HSRB) in May 2006. The HSRB 

concluded that, while informative, the studies are not appropriate for use by the Agency 

in either the individual carbofuran or N-methyl carbamate cumulative risk assessment. 

This decision was based upon the following, for all three studies: small sample size, lack 

of control subjects, and highly variable results for red blood cell cholinesterase activity. 

Additionally, the board had concerns regarding inappropriate application methods in the 

dermal studies and also determined that the conduct of the dermal studies was unethical.

There are currently one technical, two manufacturing-use, and six end-use 

products registered under Section 3 of the Federal Insecticide, Fungicide and Rodenticide 

Act (FIFRA). There are also 77 active Special Local Need registrations under Section 

24(c) of FIFRA. This Interim Reregistration Eligibility Decision document evaluates 

risks from all currently registered uses. 

2
 EPA followed a 6-phase public participation process in developing this interim 

decision. This means that there were two 60-day public comment periods on the risk 

assessments. EPA released the revised human health and ecological risk assessments for 

the second phase of public comment (Phase 5) on March 22, 2006. This IRED document 

will be posted in the carbofuran reregistration docket, along with any revised risk 

assessments and responses to public comments received. 

 B. Chemical Identification 

Chemical Structure: 

Common Name: Carbofuran 

Chemical Name: 2,3-dihydro-2,2-dimethyl-7-benzofuranyl-N-methylcarbamate 

Chemical Family: N-methyl Carbamate 

Empirical Formula: C12H15NO3 

CAS Registry Number: 1563-66-2 

Case Number: 0101 

OPP Chemical Code: 090601 

Molecular weight: 221.3 

Trade Names: Furadan

Basic Manufacturers: FMC Corporation 

Carbofuran is an odorless, white, crystalline solid with a melting point range of 

150-154 o C. It is slightly soluble in water, and is highly soluble in N-methyl-2-

pyrrolidone, dimethylformamide, dimethyl sulfoxide, acetone, acetonitrile, methylene 

3
chloride, cyclohexanone, benzene, and xylene. Carbofuran is stable under neutral and 

acidic conditions, but decomposes under alkaline conditions. 

C. Use Profile

 

The following is information on the currently registered uses of carbofuran, 

including an overview of use sites and application methods. 

Type of Pesticide: Restricted use systemic insecticide 

Summary of Use: Used for control of a variety of insect pests on a variety of 

field, fruit, and vegetable crops. Carbofuran is not used in 

residential settings or food-handling establishments. 

Food uses: Registered for use on the following crops/sites: 

 

Alfalfa, artichoke, banana, barley, coffee, corn (field, pop, and sweet), cotton, cucurbits 

(cucumber, melons, and squash), grapes, oats, pepper, plantain, potato, sorghum, 

soybean, sugar beet, sugarcane, sunflower, and wheat 

Non-food uses: 

Agricultural fallow land, cotton, ornamental and/or shade trees, ornamental herbaceous 

plants, ornamental non-flowering plants, ornamental woody shrubs and vines, pine, 

spinach grown for seed, and tobacco 

Target Pests: Alfalfa weevil, aphids, banana root borer, Colorado potato 

beetle, corn rootworm, cribrate weevil, cucumber beetles, 

European corn borer, flea beetles, grasshoppers, 

leafhoppers, nematodes, potato tuberworms, Southwestern 

corn borer, thrips, wireworms 

Formulation Types: Granular and flowable 

Method and Rates of Application:

Application Methods: Foliar, soil, seedling dip 

Application Equipment: Aerial equipment, chemigation systems, 

groundboom sprayers, airblast sprayers, tractordrawn spreaders, and handheld equipment. 

Application Rates: Application rates range from 0.19 (agricultural 

fallow land) to 10 lbs a.i./A (grapes and potatoes), 

depending on the application scenario. 

4
Application Timing: At plant, post-plant 

Use Classification: Restricted 

D. Estimated Usage of Pesticide

 The estimate for total domestic use (annual average) of carbofuran is nearly 1 

million pounds of active ingredient for the liquid formulation, with the majority of use 

occurring on the following crops: corn, alfalfa, and potatoes. Under the existing terms 

and conditions of the registration, sale of the granular formulation is limited to 2,500 

pounds active ingredient per year, and use is limited to pine seedlings, cucurbits, bananas 

(in Hawaii only), and spinach grown for seed. 

III. Summary of Carbofuran Risk Assessments 

 The purpose of this summary is to assist the reader by identifying the key features 

and findings of these risk assessments, and to help the reader better understand the 

conclusions reached in the assessments. The human health and ecological risk 

assessments form the basis of interim regulatory decisions for carbofuran. While the risk 

assessments and related addenda are not included in this document, they are available 

from the OPP Public Docket EPA-HQ-OPP-2005-0261 and may be accessed on the 

internet at http://www.regulations.gov. 

A. Human Health Risk Assessment

 1. Toxicity of Carbofuran 

Table 1. Acute Toxicity of Carbofuran 

Guideline No./ Study Type Species MRID No. Results Toxicity 

Category 

870.1100 Acute oral toxicity Rat Gronning and 

Kimmerle, 1974 

LD50 = 7.8 mg/kg _

 6.0 mg/kg _

I 

870.1200 Acute dermal 

toxicity 

Rabbit 44671601 LD50 = 4403 (2900 - 6685) 

mg/kg - intact skin 

III 

870.1300 Acute inhalation 

toxicity 

Rat Gronning and 

Kimmerle, 1974 

LC50 = 0.08 mg/L I 

870.2400 Acute eye irritation Rabbit 00070347 Minimal irritation III 

870.2500 Primary dermal 

irritation 

Rabbit 00054336 Primary Irritation Score = 

0.25 

IV 

870.2600 Skin sensitization Guinea 

pig 

44827101 Non sensitizer N/A 

5
 Animal toxicity studies show that, as with other N-methyl carbamate pesticides, 

the critical effect of carbofuran for various exposure durations is cholinesterase 

inhibition. Similar to other N-methyl carbamate pesticides, inhibition is followed by 

rapid recovery of cholinesterase. 

 The toxicology database is considered to be adequate for selection of endpoints 

for risk assessment. 

 EPA considered a human oral study as part of its deliberations; however, due to 

serious scientific limitations, EPA has not included it in the carbofuran risk assessment 

that supports the reregistration decision outlined in this document. The results of the rat 

comparative ChE study are considered to be the most suitable for risk assessment 

purposes. 

 Developmental toxicity studies in both the rat and rabbit show no evidence of 

quantitative or qualitative increased susceptibility of the developing fetuses. There was 

evidence of qualitative increased susceptibility in the rat multi-generation reproduction 

study since offspring toxicity was manifested as decreased pup survival between birth 

and post natal day (PND) 4, whereas parental toxicity was limited to decreased body 

weight gain. 

 The rat developmental neurotoxicity study also provided evidence of a qualitative 

increase in offspring susceptibility. At the lowest observed adverse effects level 

(LOAEL) of 75 ppm, maternal toxicity was manifested as decreased body weight gain 

and food consumption, whereas offspring toxicity at this dose was manifested as 

increased mortality, decreased pup viability, and decreased fetal weight. 

Carbofuran is primarily metabolized into three phenolic carbamate metabolites 

and into 3-hydroxy carbofuran. The trio of phenolic metabolites is not deemed to be of 

toxicological significance. For risk assessment purposes, 3-hydroxycarbofuran is 

considered to be of equal toxicity as parent carbofuran. 

FQPA Safety Factor

The FQPA Safety Factor (as mandated by the Food Quality Protection Act of 

1996) is intended to provide up to an additional 10-fold safety factor (10X), to account 

for potential pre- and post-natal toxicity and completeness of the data with respect to 

exposure (food, water, and non-occupational) and toxicity to infants and children. In the 

case of carbofuran, there was no evidence of either quantitative or qualitative increased 

susceptibility of fetus/pups in the rat or rabbit developmental toxicity studies. There was 

evidence of qualitative increased susceptibility in the rat multi-generation reproduction 

study and the rat developmental neurotoxicity study. BMD (benchmark dose) analyses of 

the comparative ChE rat study revealed that the BMD values for the PND11 pups were 

lower (i.e., more sensitive) than those of adult rats. The Agency has retained a FQPA 

factor (for database uncertainties) in the derivation of the carbofuran acute PAD, which is 

based on brain ChE inhibition in rat pups. The magnitude of this factor is 5X. This 

6
factor was based on the following rationale: the comparative ChE rat study measured 

only brain ChE inhibition, red blood cell (RBC) ChE inhibition in adult rats is the more 

sensitive endpoint; there is an observed 5-fold difference between brain ChE inhibition 

and RBC ChE inhibition in adult rats; and the assumption is made that for rat pups, there 

will be a similar 5-fold difference in RBC vs. brain ChE inhibition. See also the 

discussion below under “Endpoints selected for risk assessment.” 

Cancer Classification

Carbofuran does not appear to possess mutagenic activity and was negative in 

both rat and mouse oncogenicity assays. Carbofuran is classified as a "Not likely" human 

carcinogen based on the lack of evidence of carcinogenicity in mice or rats. 

Endpoints selected for risk assessment

 There are several studies available which measured acute ChE inhibition at or 

near the peak time of inhibition (15 to 45 minutes), and which the Agency was able to use 

to determine the derivation of the acute RfD and acute PAD. These include two studies 

performed by the registrant: 1) a time course study in which male and female rats were 

dosed at 0.5 and 1.0 mg/kg, and 2) a comparative ChE study where adult and juvenile 

(PND11) rats were dosed at 0.3, 0.6, and 1.0 mg/kg. A third ChE study was performed in 

support of the Agency’s cumulative risk assessment for the N-methyl carbamates. In this 

study, scientists from the USEPA National Health and Environmental Effects Research 

Laboratory (NHEERL) performed dose-response studies in male rats, where brain and 

RBC ChE inhibition, along with motor activity, were measured. This study included 

doses of carbofuran ranging from 0.1 mg/kg to 1.5 mg/kg. 

 The risk assessment for carbofuran is based on BMD values, rather than No 

Observed Adverse Effect Level (NOAEL) or LOAEL values. The Agency used this 

method because NOAELs and LOAELs do not necessarily offer the best characterization 

between dose and response for a given chemical, and are often limited by dose selection. 

In order to evaluate the appropriate point of departure (PoD) for ChE inhibition, EPA 

performed a BMD analysis using the available comparative cholinesterase study in rats 

(the most sensitive species). 

 The dose at which 10% ChE inhibition is observed (BMD10) and the lower 95% 

confidence intervals (BMDL10) were estimated from the comparative cholinesterase 

study. The BMD10 was selected because it is generally at or near the limit of sensitivity 

for discerning a statistically significant decrease in ChE activity across the blood and 

brain compartments, and is a response level close to the background ChE. Moreover, the 

Agency believes that 10% is likely to be protective to other toxicities, such as clinical 

signs and/or behavioral endpoints. 

 The BMDL10 of 0.03 mg/kg/day for inhibition of ChE in the brain of PND11 male 

pups was selected for derivation of the acute RfD. The following uncertainty factors 

were applied: 5X FQPA safety factor based on database uncertainties, 10X for variability 

7
among individuals, and 10X for interspecies extrapolation. The resulting aPAD for the 

general population and all population subgroups is 0.00006 mg/kg/day. 

 The Agency’s analysis of the brain ChE inhibition data from the comparative 

ChE study suggests that PND 11 pups are 2.5X more sensitive than adults (0.11 mg/kg 

and 0.12 mg/kg for male and female adult rats, respectively, as compared to 0.04 mg/kg 

and 0.05 mg/kg for male and female PND11 rats, respectively). In addition, the 

following uncertainties exist: 1) RBC ChE inhibition may be a more sensitive endpoint 

compared to brain ChE; 2) pups appear to be more sensitive than adult rats; and 3) due to 

the lack of reliable RBC data in pups, there is residual uncertainty in the available 

toxicology database. Given these uncertainties, the Agency has retained a 5X FQPA 

safety factor in the derivation of the carbofuran acute RfD. Due to the fact that the RfD 

is based on a BMDL10 in rat pups, there is no need to account for the 2.5X sensitivity 

observed in pups vs. adults. 

 A chronic RfD was not selected because the acute RfD is considered protective 

of chronic exposures, given that carbofuran-induced inhibition of ChE activity is 

reversible (within 24 hours). The longer-term exposures could be considered a series of 

acute exposures. 

 

 Table 2. Toxicity Endpoints for Human Health Risk Assessment for Carbofuran 

Exposure 

Scenario 

Dose Used in Risk 

Assessment, 

UF 

FQPA SF and Endpoint 

for Risk Assessment Study and Toxicological Effects 

Acute Dietary 

All Populations 

BMDL10 = 0.03 mg/kg/day 

UF = 500 

Acute RfD = 0.00006 

mg/kg/day 

FQPA SF = 5X 

aPAD = 0.00006 

mg/kg/day 

Comparative ChE Study 

BMDL10 = 0.03 mg/kg/day, based on 

cholinesterase inhibition in the brain 

of postnatal day 11 (PND11) male 

pups. 

Short, Intermediate and 

Long-Term Dermal 

(Occupational) 

BMDL10 = 0.01 mg/kg/day 

UF=100 

Dermal absorption rate (rat 

dermal study) = 6% 

MOE ≥ 100 does not 

exceed level of concern 

Special ChE Study (USEPA 2005) 

BMDL10 = 0.01 mg/kg/day, based on 

RBC cholinesterase inhibition in adult 

rat 

Short, Intermediate and 

Long-Term Inhalation 

(Occupational) 

BMDL10 = 0.01 mg/kg/day 

UF=100 

Inhalation absorption rate = 

100% 

MOE > 100 does not 

exceed level of concern 

Special ChE Study (USEPA 2005) 

BMDL10 = 0.01 mg/kg/day, based on 

RBC cholinesterase inhibition in adult 

rat 

Cancer (oral, dermal, 

inhalation) "Not likely" Risk assessment not required 

 

8
2. Dietary Exposure and Risk from Food and Water 

 A refined (Tier 3) acute probabilistic dietary risk assessment was conducted 

using DEEM-FCIDTM, Version 2.02, which incorporates consumption data from 

USDA’s CSFII, 1994-1996 and 1998, as well as monitoring data from PDP and the FDA 

Surveillance Monitoring Program, estimated percent crop treated information, and 

processing/cooking factors, where applicable. EPA has determined that, because of the 

rapid reversibility of cholinesterase inhibition related to carbofuran, the acute dietary 

assessment would be protective of any chronic exposures in the diet. Therefore, a 

separate chronic dietary exposure assessment was not conducted. Exposure estimates 

are reported in milligrams per kilogram of body weight per day, and risk is expressed as 

a percent of the aPAD. Exposure estimates that are less than 100% of the PAD are 

below the EPA’s level of concern. 

 Combined anticipated residues of carbofuran and 3-hydroxycarbofuran on food 

were included in the acute assessment. Acute anticipated residues for many foods 

(artichoke, cucumber, melons, milk, peppers, potatoes, pumpkin, squash, strawberry and 

sweet corn) were derived using USDA Pesticide Data Program (PDP) monitoring data 

from recent years (through 2003 for all commodities except milk, for which recently 

available 2004 data were used). For artichokes, PDP data for peppers were used as 

surrogate data. Anticipated residues for bananas and grapes were derived using 

monitoring data from the 2000 Carbamate Market Basket Survey. Most of the samples 

analyzed by the PDP and the Carbamate Market Basket Survey Task Force contained no 

detectable residues of carbofuran or its 3-hydroxy metabolite. 

 A value equal to 1⁄2 the combined limits of detection (LODs) of carbofuran and 3-

hydroxycarbofuran was assumed for samples with non-detectable residues, with zeros 

incorporated to account for the percent of the crop not treated with carbofuran. For 

commodities with no monitoring data available (cranberries, coffee, sugar beets, 

sugarcane and sunflowers) and for field crops that are typically blended prior to 

marketing (barley, field corn, oats, rice, soybean, and wheat), anticipated residues were 

based on field trial data. Although PDP data are generally assumed to provide more 

refined estimates of exposure than field trial data, they may sometimes overestimate 

exposure, particularly for blended commodities, such as those listed above, with low 

percent crop treated estimates, no detections in the PDP data and relatively high 1⁄2 LOD 

values. Therefore, field trial data were used, with adjustments for percent crop treated, 

to provide more refined exposure estimates for these commodities. Exposure estimates 

are reported in milligrams per kilogram of body weight per day, and risk is expressed as 

a percent of the aPAD. Exposure estimates that are less than 100% of the aPAD are 

below the EPA’s level of concern. 

 The estimated acute dietary (food only) exposure exceeds the Agency’s level of 

concern for the U.S. population and all reported population subgroups at the 99.9th 

percentile of exposure. Carbofuran dietary exposure at the 99.9th percentile was 

estimated at 0.000154 mg/kg/day for the U.S. population (260% of the aPAD) and 

9
0.000292 mg/kg/day (490% of the aPAD) for children 1-2 years old, the population 

subgroup with the highest estimated dietary exposure. See Table 3 below. 

Table 3. Summary of Acute Dietary Exposure and Risk for Carbofuran for Food Alone 

(aPAD = 0.00006 mg/kg/day) at 99.9th Percentile of Exposure 

Population Subgroup Dietary Exposure (mg/kg/day) % aPAD 

General US Population 0.000154 260 

Infants < 1 year 0.000182 300 

Children 1-2 years old 0.000292 490 

Children 3-5 years old 0.000290 480 

Surface Water Estimated Drinking Water Concentrations

 For surface water, estimated environmental drinking water concentrations 

(EDWCs) were calculated using the PRZM/EXAMS model. If appropriate, regional 

percent cropped area factors (PCA) were considered. EDWCs represent the range of 

concentrations that are expected to result from the annual use of carbofuran over a 30-

year period at lowest and maximum application rates in different growing areas 

nationally, and vary over several orders of magnitude across use areas. Only acute 

values are presented here since the Agency did not assess chronic or cancer dietary risks 

for carbofuran. For an in-depth discussion of modeling and the range of values, please 

see the carbofuran drinking water assessment. 

Table 4. Acute EDWCs (ppb) for Carbofuran on Selected Agricultural Crops. 

 (Ranges of acute concentrations based on a distribution of default PCAs.) 

Location/Crop Using Lowest Label Rate1 Using Highest Label Rate1

Potato 0.25-3.1 1.6-20 

CA Grape 0.4 4.3 

Alfalfa 0.13-1.5 1.1-12 

Alfalfa 0.11-1.2 0.86-10 

ID Potato -- 10 

Tobacco 8-17 12-26 

Cotton 14-18 57-72 

 Corn 19-36 26-49 

 Sorghum 2.4-7.8 23-75 

1. One-in-ten-year annual peak concentration 

 3-Hydroxycarbofuran has not been shown to form in the majority of 

environmental fate studies, with the exception of one study in which it was detected in 

low amounts as a result of soil photolysis. Therefore, 3-hydroxycarbofuran was not 

included in the Agency’s human drinking water exposure assessment. While estimation 

of potential exposure to 3-hydroxycarbofuran remains an uncertainty in the human 

drinking water assessment, it is not expected to significantly add to exposure estimates 

(maximum concentrations in monitoring were approximately 6% of carbofuran 

concentrations). 

10
Groundwater Estimated Drinking Water Concentrations

 Estimation of carbofuran in groundwater was based on a study conducted by the 

registrant. Following detection of carbofuran in ground water in Long Island, NY, FMC 

voluntarily conducted a prospective groundwater (PGW) monitoring study during 1981-

1983 near Salisbury, Maryland to assess impacts from the labeled use of carbofuran. 

Soils at the study site are sandy and promote leaching to groundwater. A corn plot had 

one application of Furadan 10G (totaling 3.0 lbs a.i./A; the labeled rate has since been 

reduced to 1 lbs a.i./A on corn for these soils). 

 Because this prospective ground water study was conducted over only one 

growing season, the reported ground water concentrations do not represent impacts from 

carbofuran use in multiple years. Thus, EPA used superpositioning techniques to provide 

estimates of concentrations following long-term (25 years) use of carbofuran at current 

label rates. These estimation techniques assumed chemical transformation processes and 

transport and interaction mechanisms are linear with respect to concentration. Based on 

these assumptions, the carbofuran concentrations in groundwater for various application 

rates were estimated (Table 5). EDWCs for ground water, estimated from PGW 

monitoring data, range from 1.4 ppb (low application to alfalfa) to 110 ppb (high 

application to grapes). 

Table 5. Estimated 90-day Average Concentrations of Carbofuran in Shallow 

Groundwater for a Range of Application Rates 

Crop Application Rate (lbs a.i./A) Groundwater EDWCs (ppb) 

Alfalfa 0.125 1.4 

Cotton 0.25 2.8 

Corn 1.0 11 

Corn 2.0 22 

Tobacco 4.0 44 

Grapes 10.0 110 

Water Monitoring Data

 Available groundwater monitoring studies conducted in the 1980s at locations 

associated with carbofuran uses report peak carbofuran concentrations ranging from 1.4-

176 ppb. Several studies reported peak concentrations in the 50 ppb range resulting from 

application rates comparable to currently used application rates. Non-targeted 

monitoring tends to show detections at lower concentrations, rarely exceeding 1 ppb, 

although higher concentrations have been reported. Over the last decade, non-targeted 

ground water monitoring reports indicate fewer locations with detections. Consistent 

with its environmental fate properties, carbofuran has been detected more frequently and 

at higher concentrations in acidic environments. The most vulnerable drinking water 

sites appear to be shallow private wells near carbofuran use areas, where the ground 

water has a lower pH. 

11
 Only non-targeted monitoring data are available for surface water; consequently, 

detections cannot be directly associated with specific use sites or locations that are most 

vulnerable to contamination. Few detections exceeding 1 ppb have been found since the 

mid-1990s. 

 Detectable residues of carbofuran (no 3-hydroxycarbofuran found) were found in 

14 out of 1418 PDP water samples (data from 2001-2003). Carbofuran residues ranged 

from 0.001 ppb to 0.079 ppb. These data were not deemed appropriate for use in risk 

assessment as the data may not be reflective of areas with significant carbofuran use and 

the community water systems sampled by PDP are generally deep ground water or 

surface water systems and do not include private wells. Since the highest carbofuran 

concentrations are likely to occur in shallow, private wells in areas where carbofuran is 

used, use of the PDP data would not be protective of people whose drinking water comes 

from such wells. 

 The Agency evaluated data from state, USGS and registrant monitoring programs. 

The EPA Office of Water collected monitoring data for compliance with the Safe 

Drinking Water Act and in a 2002 report described levels of carbofuran found in 16 states 

in finished drinking water. No system exceeded the carbofuran MCL of 40 ppb; 

however, several systems exceeded concentrations of 7 and 4 ppb. Because these data 

were collected for compliance purposes (i.e., not to determine acute exposures) they are 

not included directly into the risk calculations. Some forms of drinking water treatment 

such as softening may reduce concentrations of carbofuran in finished water, but other 

water treatment methods do not affect concentrations. 

 3. Residential and Other Non-occupational Risk 

 Carbofuran is a restricted use pesticide and is not registered for residential or 

other non-occupational uses. Therefore, no residential exposure and risk assessment was 

conducted for carbofuran. 

 4. Aggregate Exposure and Risk 

The Food Quality Protection Act (FQPA) amendments to the Federal Food, Drug 

and Cosmetic Act (FFDCA, Section 408(b)(2)(A) (iii) require “that there is a reasonable 

certainty that no harm will result from aggregate exposure to the pesticide chemical 

residue, including all anticipated dietary exposures for which there is reliable 

information.” Aggregate exposure will typically include dietary exposures (food plus 

drinking water), residential uses of a pesticide, and other non-occupational sources of 

exposure. 

There are no residential uses of carbofuran. Therefore, when evaluating 

aggregate exposures, only the dietary pathways of food and drinking water would be 

relevant. 

12
Acute dietary exposure and risk from food alone exceeds the Agency’s level of 

concern (i.e., >100% aPAD). For the most highly exposed subpopulation (children 1-2 

years old), the acute dietary (food only) risk estimate is 490% of the aPAD. For the 

general U.S. population, the acute dietary (food only) risk estimate is 260% of the aPAD. 

Using the PRZM/EXAMS model, the acute EDWCs in surface water range from 

0.11 ppb (low application rate to alfalfa) to 75 ppb (maximum label application rate to 

sorghum) for nine crop location scenarios. EDWCs for ground water, based on 

prospective ground water monitoring data, range from 1.4 ppb (low application to alfalfa) 

to 110 ppb (maximum application to grapes). 

If one assumes that there are no acute dietary food exposures to carbofuran and all 

of the allowable exposure occurred through water sources (i.e., assuming the aPAD of 

0.00006 mg/kg/day is completely allocated to exposure to residues in water), the drinking 

water level of concern (DWLOC) would be 2.1 ppb for the general U.S. population and 

0.6 ppb for infants and children. These values are based on daily water consumption 

estimates of two liters for adults and one liter for infants and children. DWLOCs based 

on consumption of a single 8 ounce serving of water would be 2.6 ppb for infants and 

children and 18 ppb for adults. Therefore, even if all of the allowable dietary exposure 

(i.e., the entire aPAD or “risk cup”) occurred through a single serving of drinking water, 

the Agency would have concerns for acute exposure to carbofuran, particularly for 

individuals (both adults and children) who may derive their water from vulnerable 

watersheds that are highly cropped and where carbofuran applications may be made up to 

the maximum label rates. Exposure to individuals (adults) whose drinking water comes 

from sources where crop/location scenarios result in lower EDWCs (scenarios with lower 

applications) may not be of concern if the entire risk cup were available for water 

exposures. 

5. Occupational Exposure and Risk 

 Workers can be exposed to a pesticide through mixing, loading, and/or applying a 

pesticide, or re-entering treated sites. Occupational risk is measured by a Margin of 

Exposure (MOE), which describes how close the occupational exposure comes to a point 

of departure (e.g., BMD or NOAEL). The target MOE for carbofuran is 100, meaning 

that MOEs that fall below 100 indicate a possible need for mitigation. 

 Occupational handler scenarios were assessed using the short-term endpoint for 

dermal and inhalation exposures. The short-term dermal and inhalation endpoint is a 

BMDL10 of 0.01 mg/kg/day, based on red blood cell ChE inhibition in adult male rats. 

Additionally, a dermal absorption factor of 6% has been used, based on a 24-hour 

exposure duration from a dermal penetration study. The UF for both dermal and 

inhalation endpoints is 100 (10X for intraspecies variability and 10X for interspecies 

extrapolation). Dermal and inhalation exposures were combined to assess handler risk. 

 Occupational handler risk estimates have been assessed for short-term exposures. 

Intermediate-term and long-term exposures were not assessed, as ChE inhibition does not 

13
increase with continued exposure to carbofuran and because of the rapid reversibility of 

ChE inhibition. 

 No chemical-specific data for assessing human exposures during pesticide 

handling activities were submitted, so short-term dermal and inhalation exposures for 

handlers were developed using the Pesticide Handlers Exposure Database (PHED) 

Version 1.1. 

The Agency has determined that there are potential exposures to individuals who 

mix, load, apply, and otherwise handle carbofuran during the usual use patterns 

associated with the pesticide. Thirteen major occupational exposure scenarios were 

identified based on the type of equipment that potentially can be used to make carbofuran 

applications. These scenarios are listed in Table 6 below. 

 The calculations of short-term total risks indicate that most occupational handler 

risks are above the Agency’s level of concern (i.e., MOEs less than 100), even at the 

maximum mitigation level (engineering controls) for all handler scenarios except 

mixing/loading granulars for tractor-drawn spreader application (cucurbits, spinach) and 

flagging for spray application (corn, sugarcane). Additionally, total MOEs for 

mixing/loading/applying liquids for application to any crop via backpack sprayer were 

greater than 100 with baseline protection. Total MOEs for mixing/loading/applying 

liquids for low-pressure handwand application were greater than 100 with PPE2 

protection (single layer protection, gloves, and PF5 respirator). Table 6 below shows 

MOEs for the remaining handler scenarios, which do not reach 100, even with 

engineering controls. 

Table 6. Summary of Handler Scenarios Total (Dermal and Inhalation) MOEs with 

Engineering Controls (i.e., Maximum MOEs) 

Exposure Scenario Crop 

Application 

Rate (lbs 

a.i./A) 

Daily Area 

Treated 

(Acres/day) 

Total 

MOE 

MIXER/LOADER 

Alfalfa, Corn (field and pop), 

Cotton 1 lb 1200 0.96 

Potatoes 2 lb 350 1.7 

Sorghum 0.50 1200 2.0 

Small grains (wheat, barley, 

oat), Soybeans 0.25 1200 3.9 

Ag Fallow/Idle land 0.19 350 18 

Corn (sweet), Sunflowers 0.50 350 6.8 

Mixing/Loading 

Liquids for Aerial 

application 

Sugarcane 0.75 350 4.4 

Mixing/Loading 

Liquids for 

Chemigation 

application 

Grapes 6 350 0.56 

Grapes 10 80 1.5 

Ornamentals 10 40 2.9 

Coffee (seedbeds) 6.90 80 2.1 

Mixing/Loading 

Liquids for 

Groundboom 

application Tobacco 6 80 2.4 

14
Exposure Scenario Crop 

Application Daily Area Total Rate (lbs Treated MOE a.i./A) (Acres/day) 

Peppers 3 80 4.8 

Sugar Beets 2 200 3.0 

Sunflowers 1.40 80 10 

Alfalfa, Corn (field and pop), 

Cotton 1 200 6.0 

Potatoes 3 80 4.8 

Sugarcane 0.75 80 20 

Sorghum 0.50 200 12 

Corn (sweet) 1 80 15 

Artichoke 1 80 15 

Small grains (wheat, barley, 

oat), Soybeans 0.25 200 23 

APPLICATOR

Alfalfa, Corn (field and pop), 

Cotton 1 1200 1.6 

Potatoes 2 350 2.7 

Sorghum 0.50 1200 3.2 

Small grains (wheat, barley, 

oat), Soybeans 0.25 1200 6.4 

Corn (sweet), Sunflowers 0.50 350 11 

Ag Fallow/Idle land 0.19 350 29 

Aerial application 

Sugarcane 0.75 350 7.2 

Grapes 10 80 2.6 

Ornamentals 10 40 5.2 

Coffee (seed beds) 6.90 80 3.2 

Tobacco 6 80 4.4 

Peppers 3 80 8.4 

Sugar Beets 2 200 5.2 

Sunflowers 1.40 80 18 

Alfalfa, Corn (field and pop), 

Cotton 1 200 10 

Potatoes 3 80 8.4 

Sugarcane 0.75 80 34 

Sorghum 0.50 200 20 

Corn (sweet) 1 80 26 

Small grains (wheat, barley, 

oat), Soybeans 0.25 200 40 

Groundboom 

application 

Artichoke 1 80 26 

Applying Granulars for 

Tractor-drawn 

Spreaders application 

Cucurbits, spinach 0.50 80 52 

FLAGGER

Potatoes 2 350 48 

Flagging for Spray Sorghum 2 1200 14 

application Small grains (wheat, barley, 

oat), Soybeans 2 1200 14 

15
 The Agency did not assess risks to workers mixing, loading or applying flowable 

carbofuran to pine seedlings as a slurry dip because there are no appropriate exposure 

data to evaluate the risks at this time. In the absence of appropriate data, the exposure for 

dipping pine seedlings is considered to be less than or similar to exposures from 

handwand applications to ornamentals with regards to amount of product which could be 

handled. Total MOEs for mixing/loading/applying liquids for low-pressure handwand 

application were greater than 100 with single layer clothing, gloves, and a PF5 respirator. 

As a conservative measure, this level of protective clothing will be required for flowable 

carbofuran use on pine seedlings. 

Postapplication Occupational Risk

 For workers entering a treated site, restricted entry intervals (REIs) are calculated 

to determine the minimum length of time required before workers can safely reenter (i.e., 

MOEs ≥ 100). Many of the registered uses of carbofuran involve applications to the soil 

only and do not result in treatment of plant foliage. Therefore, these scenarios were not 

included in the postapplication risk assessment. However, multiple applications of sprays 

to foliage may occur for a number of crops. EPA expects harvesting for all these 

particular crops to be fully mechanized. 

 For those crops for which postapplication exposures are expected to occur, 

exposure was estimated using dislodgeable foliar residue (DFR) data for carbofuran 

applied to corn, cotton, and potatoes. MOEs failed to reach 100 within the currently 

prescribed REIs for most of these crops. 

Short-term exposures may occur for several crops requiring reentry by crop 

advisors. Such exposures also may occur for field workers involved in irrigation 

activities, early season hoeing and thinning, and de-tasseling corn grown for seed. 

 A 14-day restricted entry interval is specified on current carbofuran labeling for 

foliar application to corn, sunflowers, and sorghum. A 48-hour REI is specified on 

product labels for all other crops, based on the acute toxicity of carbofuran (per EPA’s 

Worker Protection Standard). 

 Most crops with postapplication activities failed to reach MOEs of 100 within the 

currently prescribed REIs. Only sunflower and sorghum had postapplication MOEs of 

100 within the label REI of 14 days.

16
Table 7. Crop Groupings, Selected Transfer Coefficients, Treated Crops, Rates, 

Proposed REIs, Current REIs 

Transfer Coefficient 

(cm2/hr) 

# of days until MOE 

Transfer reaches 100 

Coefficient 

Group 

Crop 

Max 

Foliar 

Rate 

(lb 

ai/acre) 

DFR 

Data Used 

Low Med High Low Med High 

Soybeans 0.25 Cotton 100 1500 6 12 

Small Grains 0.25 Cotton 100 1500 6 12 

Alfalfa 1 Potatoes 100 1500 4 >14* 

Field/row 

crops, 

Low/medium 

Sugar Beets 2 Potatoes 100 1500 8 >14* 

Corn Corn (MN site) 100 1000 7 10 

(field and 

pop) 

1 

Corn (CA site) 100 1000 25 >32* 

Corn Corn (MN site) 100 1000 17000 2 10 >11* 

(sweet) 

0.5 

Corn (CA site) 100 1000 17000 18 32 >32* 

Sunflowers 0.5 Potatoes 100 1000 0 13 

Field/row 

crops, 

Tall 

Sorghum 0.5 Potatoes 100 1000 0 13 

Sugarcane Sugarcane 0.75 Potatoes 100 1000 2000 2 >14* 

Vegetable, root Potatoes 1 Potatoes 300 1500 4 >14* 

* Studies ended at the number of days indicated, and MOEs still had not reached 100. 

 Drench applications made to container grown nursery stock may result in dermal 

exposure to workers performing postapplication reentry tasks and for workers handling 

treated soil while moving containers. However, the Agency has no exposure data to 

estimate these exposures. 

 6. Smoker Assessment 

 A short-term inhalation risk assessment for adult smokers has been completed, 

since carbofuran is registered for use on tobacco. Based on the short-term inhalation 

BMDL10 of 0.01 mg/kg/day (based on red blood cell ChE inhibition in adult male rats), 

the short-term MOE for carbofuran exposure from the use of tobacco is 12. This 

conservative risk estimate is above HED’s level of concern for inhalation exposure to 

carbofuran. 

 7. Human Incident Data 

 For a review of the pesticide poisoning incident data for carbofuran, EPA 

consulted the following data bases: (1) OPP Incident Data System (IDS); (2) Poison 

Control Centers (PCC); (3) California Department of Pesticide Regulation; (4) National 

Pesticide Telecommunications Network (NPTN), and (5) National Institute of 

Occupational Safety and Health’s Sentinel Even Notification System for Occupational 

Risks (NIOSH SENSOR). In all, more than 700 possible carbofuran poisoning incidents 

were reported. 

 In the IDS, from 1996 through 2003, there have been 42 reported incidents from 

carbofuran exposure. Common among these reports is evidence that carbofuran is a 

17
prevalent cause of eye problems, which was reported in about one quarter of all the cases. 

Although data were often limited, most cases involved failure to wear proper protective 

equipment, or they occurred when workers were cleaning or repairing spray equipment. 

 PCC results for the years 1993 through 2001 for occupational and nonoccupational incidents involving adults and older children and for children under age six 

were compared between carbofuran and all other reported pesticides. The PCC data 

indicate that carbofuran exposure is likely to result in more serious medical outcomes and 

serious medical care than exposure to other pesticides. Most of the reported symptoms 

for carbofuran incidents were specific to cholinergic poisoning and most resulted from 

dermal and inhalation exposure, rather than oral exposure. While approximately four 

percent of the non-occupational incidents could be attributed to misuse, or misreading of 

the label, it was not possible to determine what percentage of occupational incidents were 

attributable to misuse. 

 On the list of the top 200 chemicals for which NPTN received calls from 1984 to 

1991 inclusively, carbofuran was ranked 37th, with 103 incidents in humans reported. 

 In the NIOSH/SENSOR data (surveillance in seven states) there were 19 reports 

due to carbofuran alone, out of 4,221 reports. 

 A 1997 EPA incident review stated that, overall, carbofuran was judged second 

among 28 pesticides on measures of hazard derived from California and PCC data. Most 

of the risk from this pesticide is due to use by pesticide handlers, especially mixer/loaders 

who handle the concentrated material. Less often, groups of people have been poisoned 

from spray drift of from exposure to field residue. A 1998 case in California illustrates 

the effects from field residues when workers reentered treated cotton fields within two 

hours, instead of the required 48 hours, after application. Such residues are capable of 

causing moderate to relatively serious effects which require medical treatment. 

 Detailed descriptions of incidents reported to the California Pesticide Illness 

Surveillance Program from 1982 through 2002 identified a total of 88 cases in which 

carbofuran was either used alone or in combination with other chemicals, but was judged 

to be responsible for the reported health effects. The majority of illnesses were of a 

systemic type. The majority of incidents occur among handlers who mix, load, and apply 

carbofuran in agricultural fields. 

 The number and rate of poisoning cases due to carbofuran exposure is sufficient 

to warrant priority attention to risk reduction measures for this pesticide. 

B. Environmental Risk Assessment 

The ecological risk assessment for carbofuran primarily focused on the liquid 

(flowable) formulation because it makes up the greatest portion (≥ 99%) of carbofuran’s 

uses. However, since some granular product uses remain, a summary of the associated 

18
ecological risk of these uses is presented separately in the ecological risk assessment (see 

section 4.0 of Appendix 1 of the ecological risk assessment). 

Terrestrial and aquatic plants were not a part of this risk assessment. Since the 

mode of action of carbofuran is cholinesterase inhibition and both terrestrial and aquatic 

plant studies show no phytotoxic effects, the Agency does not have concerns for plants as 

a result of use of carbofuran. 

Three lines of evidence were examined to evaluate the risk of the use of flowable 

carbofuran products to non-target animal species. They include a screening level risk 

assessment (deterministic), a refined assessment (probabilistic) for aquatic risks and acute 

risks to birds, and the consideration of field data for carbofuran. 

First, standard screening level quotient models were used for estimating the acute 

and chronic risk to non-target aquatic and terrestrial organisms associated with the major 

uses of flowable carbofuran. This screening level ecological risk assessment compared 

toxicity endpoints from ecological toxicity studies to estimated environmental 

concentrations (EECs) based on environmental fate characteristics and pesticide use data. 

To evaluate the potential risk to non-target organisms from the use of carbofuran 

products, the Agency calculated risk quotients (RQ), which are the ratio of the EEC to the 

most sensitive toxicity endpoint values, such as the median lethal dose (LD50) for 

terrestrial organisms or the median lethal concentration (LC50) for aquatic organisms. 

These RQ values are then compared to the Agency’s levels of concern (LOCs), given in 

Table 8, which indicate whether a pesticide, when used as directed, has the potential to 

cause adverse effects on non-target organisms. When the RQ exceeds the LOC for a 

particular category, (e.g., endangered species), the Agency presumes a risk of concern to 

that category. These risks of concern may be addressed by further refinements of the risk 

assessment or mitigation. Use, toxicity, fate, and exposure are considered when 

characterizing the risk, as well as the relative degree of uncertainty in the assessment. 

Table 8. EPA’s Levels of Concern and Associated Risk Presumptions 

Risk Presumption LOC 

terrestrial 

animals

LOC 

aquatic animals

Acute Risk - there is potential for acute risk 0.5 0.5 

Acute Endangered Species - endangered species may be 

adversely affected 

0.1 0.05 

Chronic Risk - there is potential for chronic risk 1 1 

Secondly, to help understand the ecological risk estimates derived from the 

screening level (deterministic) assessment, probabilistic methods were employed to 

provide more refined risk estimates that move away from the protective assumptions of 

the quotient model by using less conservative exposure scenarios and biological 

information on wildlife species likely to be associated with carbofuran use. The refined 

probabilistic assessment models estimate the magnitude and probability of acute effects 

19
to non-target species occurring from pesticides by integrating distributions of carbofuran 

exposure with distributions of toxicity. The refined risk assessment addresses bird 

mortality (acute), as well as survival and reproductive (chronic) effects to fish and aquatic 

invertebrates following application of carbofuran. The probabilistic models and methods 

were subjected to external peer review by the FIFRA Science Advisory Panel. 

Lastly, available field data, including field studies, monitoring programs, and 

well-documented wildlife kill incident reports attributed to the normal agricultural use of 

flowable carbofuran were examined. 

All three lines of evidence support the conclusion that there are risk concerns to 

both aquatic and terrestrial species from acute and chronic exposure following the use of 

flowable carbofuran: risk concerns are particularly high for avian species. 

For a more detailed explanation of the ecological risks posed by the use of 

carbofuran, refer to “Revised Ecological Carbofuran RED Chapter,” dated March 8, 

2006. 

 

 1. Environmental Fate and Transport 

Carbofuran is highly mobile in soils and can therefore leach into groundwater and 

enter surface water as runoff. Carbofuran breaks down into several degradates though 

hydrolysis, photodegradation and moderate bacterial degradation at rates that depend on 

environmental conditions. Hydrolysis is faster in water with a pH ≥ 7 (basic conditions), 

with a half-life ranging from a few hours to 28 days. Carbofuran is stable to hydrolysis in 

acidic water. Photodegradation is fast in a thin water layer, with a half-life of 6 days. In 

the top few millimeters of a sandy loam soil, carbofuran degrades in 78 days. 

There is low potential for bioconcentration of carbofuran and its metabolites/degradates. 

 2. Ecological Risk Estimation 

 a. Terrestrial Organisms 

 In its screening level (deterministic) assessment, the Agency assessed exposure to 

terrestrial organisms by first predicting the amount of carbofuran residues found on 

animal food items and then using information on typical food consumption by various 

species of birds and mammals to determine the amount of pesticide consumed. The 

amount of residues on animal feed items is based on the Fletcher nomogram and the 

current maximum and minimum application rates, maximum numbers of applications, 

and potential for residue dissipation between applications. The Fletcher nomogram is a 

model developed by Hoerger and Kenaga (1972) and modified by Fletcher (1994). 

 i) Birds 

 Carbofuran is characterized as “very highly toxic” to birds on an acute oral basis 

and “highly toxic” on a sub-acute basis. Chronic toxicity testing in birds showed dose20
related parental mortality at all test concentrations, so a NOAEL and LOAEL could not 

be established. A LOAEL of <2.0 mg/kg-diet was chosen as the toxicological risk 

assessment for chronic risk assessment, since 2.0 mg/kg-diet was the lowest dose tested. 

Table 9. Summary of Avian Toxicity Data Used for Risk Assessment 

Test Type Species 

(Citation) Endpoint Toxicity Category 

Affected 

Endpoints 

Avian acute effects (oral) 

Fulvous whistling duck 

(Dendrocygna bicolor) 

(Hudson et al., 1984) 

LD50 = 

0.238 mg/kg 

Very highly 

toxic NA 

Avian chronic effects 

(reproduction) 

Mallard duck (Anal 

platyrhynchos) 

(Roberts et al./1982b) 

NOAEC: 

not 

determined 

LOAEC = 2 

ppm 

NA 

Dose-related 

parental 

mortality at all 

test 

concentrations 

 Acute RQs exceed the LOC for all uses of flowable and granular carbofuran. 

Table 10 presents the RQs for flowable carbofuran as they relate to the minimum and 

maximum use rates on various crops. The lower end of the range represents RQ values 

associated with large birds whose body weight is equivalent to 1,000 g, while the higher 

end of the RQ range is associated with small birds of 20 g. For RQs calculated for use of 

granular carbofuran, see the Granular Carbofuran Risk Assessment. 

Table 10. Avian (Herbivore ) Acute RQs for Flowable Carbofuran Based on Filvous 

Whistling Duck LD50 of 0.238 mg/kg (Level of Concern = 0.5) 

RQ Values at Minimum 

Application Rates 

RQ Values at Maximum 

Crop Application Rates 

Large Birds Small Birds Large Birds Small Birds 

Alfalfa 17 144 134 1,150 

Corn (all) 67 575 804 6,898 

Cotton 28 241 63 538 

Grapes 201 1,724 268 2,299 

Potatoes 67 575 157 1,345 

Small grains (wheat, oats, barley) 17 144 63 538 

Sorghum 20 5,633 27 6,553 

Soybeans 17 144 63 538 

Sugarcane 67 575 188 1,613 

Sunflowers 17 241 125 1,075 

Tobacco 80 690 121 1,035 

 The chronic risk LOC is also exceeded for all avian species in all application 

scenarios. All scenarios compared four different feeding groups: short grass, tall grass, 

broadleaf plants/insects and seeds. The lower RQ values are associated with granivores 

(seedeaters) and the higher values are associated with herbivores (short grass eaters). The 

NOAEC was <2.0 mg/kg; the Lowest Observed Adverse Effect Concentration (LOAEC) 

was 2.0 mg/kg; and at all other concentrations tested, the test birds died. 

21
Table 11. Avian Chronic RQs for Flowable Carbofuran Based on a Mallard NOAEC of 

<2.0 mg/kg (Level of Concern = 1.0) 

RQ Values at Minimum 

Application Rates 

RQ Values at Maximum 

Application Rates Crop Granivores 

(Seed) 

Herbivores 

(Short Grass) 

Granivores 

(Seed) 

Herbivores 

(Short Grass) 

Alfalfa 1 15 8 120 

Corn (all) 4 90 2 720 

Cotton 1 30 2 56 

Grapes 15 135 11 473 

Potatoes 4 60 4 224 

Small grains (wheat, oats, barley) 1 15 4 56 

Sorghum 1 30 7 690 

Soybeans 1 15 4 56 

Sugarcane 4 60 11 168 

Sunflowers 1 50 2 112 

Tobacco 5 72 5 108 

 The refined probabilistic assessment (second line of evidence), which assessed 

acute avian risk associated with use on corn and alfalfa only, predicted high mortality in 

at least some species, regardless of the application rate and method. The analysis took 

into consideration both foliar and soil applications at use rates that span the majority of 

application rates for which carbofuran is registered (0.125 to 1.0 lbs a.i./A). Based on the 

sensitivity distribution, the more sensitive the species, the higher the mortality predicted 

from exposure. It is possible that crops with a higher application rate of carbofuran 

would result in greater avian morality. Results of the refined assessment show that from 

55 to 95% of the bird species modeled will experience at least some mortality as a result 

of the application of flowable carbofuran. At the highest application rate, if exposed, 

62% of bird species will experience 10 % mortality on average, and 23% of bird species 

will have 70% mortality or greater, with a predicted maximum mortality rate of 93%. 

 ii) Mammals 

 Carbofuran is considered to be highly toxic to mammals on an acute basis. 

Chronic toxicity testing on laboratory rats showed reduced offspring survival and body 

weight reductions. 

Table 12. Summary of Mammalian Toxicity Data for Terrestrial Animals Exposed to 

Dimethoate 

Test Type Species 

(Citation) Endpoint Toxicity Category 

Affected 

Endpoints 

Mammalian acute effects 

(oral) 

Laboratory mouse (Mus 

musculus) 

(Fahmy et al. 1970) 

LD50 = 2.0 

mg/kg 

(males) 

Very highly 

toxic NA 

Mammalian chronic 

effects (3-generation 

reproduction) 

Laboratory rat (Rattus 

morvegicus) 

(Goldenthal and Rapp/1979, 

MRIDs 00030514, 

00030570, and 00079810) 

NOAEC = 

20 ppm 

LOAEL = 

100 ppm 

NA 

Decreased pup 

survival and 

pup body 

weight decrease 

22
 A refined assessment was not conducted for mammalian species. Few studies 

exist on wild mammalian species; therefore, the laboratory mouse LD50 of 2.0 mg/kg/day 

was used to calculate RQs. The deterministic assessment showed that the acute and 

chronic LOCs are exceeded for herbivorous, insectivorous, and granivorous mammals. 

RQs at the lower end of the range are associated with 1,000 g mammals, while the high 

end of the range is associated with 15 g mammals. 

Table 13. Acute RQs for all Mammal Groups LD50 2.0 mg/kg/day 

Herbivores and Insectivores Granivores Crop Large Mammal Small Mammal Large Mammal Small Mammal 

Alfalfa 8 114 0.2 2 

Corn 50 684 1 9 

Potatoes 15 213 0.4 3 

Sorghum 47 650 1 9 

Cotton 4 53 0.1 1 

LOC = 0.5 

 The chronic mammal LOC is exceeded for most uses. The lower RQ value is 

associated with seedeaters (granivores) and the higher RQ is associated with short grass 

eaters (herbivores). This is usually the case because short grass contains the highest 

pesticide residues. 

Table 14. Mammalian Chronic RQs for Applications LD50 2.0 mg/kg/day 

Herbivores and Insectivores Granivores Crop Large Mammal Small Mammal Large Mammal Small Mammal 

Alfalfa 0.1 2 0.8 12 

Corn 0.2 3 5 72 

Cotton 0.2 3 0.3 6 

Grapes 1 13 5 47 

Potatoes 0.4 6 1 22 

Sorghum 0.1 2 4 69 

LOC = 1.0 

 iii) Non-target insects 

 

 Carbofuran is characterized as highly toxic to honey bees, based on a honey bee 

acute contact study (LD50 = 0.16 μg/bee). 

Terrestrial Field Data and Incidents

 The field studies and incident data available for flowable carbofuran (third line of 

evidence) support the conclusions of the deterministic and probabilistic risk assessments; 

that is, acute risk from the use of flowable carbofuran to non-target terrestrial species is 

high. 

 The majority of controlled field studies conducted by the registrant support the 

deterministic and probabilistic models. These studies demonstrated that bird mortality 

occurs at typical to low-end application rates. Of the five studies submitted to the 

Agency, four had study designs that were adequate to meet the Agency guideline 

23
requirement for detecting significant mortality events. In the acceptably designed 

studies, bird mortality in and around treated fields relative to untreated fields was great 

enough to reasonably conclude that carbofuran treatment-related mortality was the cause 

of death. 

 From 1972 to 2000, 31 bird kill incidents have been reported following the use of 

flowable carbofuran on five of the major crops where it is registered, and these are almost 

exclusively bird kills as a result of direct exposure. A majority (27) of the kills were 

reported following carbofuran use on corn and alfalfa, the two major crops where 

carbofuran is used. Thirty-seven species with a total of 7,300 carcasses were reported 

found in twelve different states, with both primary and secondary poisonings suspected. 

 In the late 1990s, the technical registrant made a number of label changes in order 

to reduce drinking water and ecological risks of concern. These included reducing 

application rates and numbers of applications for alfalfa, cotton, corn, potatoes, soybeans, 

sugarcane, and sunflowers. EPA therefore evaluated incidents that have occurred since 

1998. Since 1998, there have been 47 carbofuran incidents reported in EPA’s Ecological 

Incident Information System (EIIS). Four of these incidents were from registered uses: 

1) 1998 in PA, use on corn (flowable), 2 grackles 

2) 1998 in PA, use on corn (flowable), 12 grackles 

3) 2000 in NM, use on alfalfa (flowable), 800-1200 snow geese and ducks, and 

4) 2000 in CA, use on alfalfa (flowable), 4 bee hives. 

The remaining incidents were from intentional misuse (28) or the legality of use was 

undetermined (14). Of the 47 incidents, 13 were attributed to flowable carbofuran, two 

were attributed to granular carbofuran, and for the remaining incidents (32) the 

formulation was not reported. 

Additionally, three incidents since 2000 (two in 2000 and one in 2004) were 

reported aggregately by the registrant, and are not in the EIIS. Details are not available 

on these incidents. 

 b. Aquatic Organisms

For exposure to aquatic fish and invertebrates, EPA considers surface water only, 

since most aquatic organisms are not found in groundwater. Surface water models are 

used to estimate exposure to freshwater aquatic animals, since monitoring data are 

generally not from studies targeted on small water bodies and primary streams within 

agroecosystems where the pesticide is used and where many aquatic animals are found. 

The modeling results used in risk calculations for carbofuran are detailed in “Revised 

Ecological Carbofuran RED Chapter,” dated March 8, 2006. 

 Carbofuran concentrations in surface water bodies were estimated using PRZM 

and EXAMS and several crop/location scenarios and application rates which were chosen 

to ensure that: (1) the greatest acreage treated with flowable carbofuran was assessed; (2) 

24
application rates covered all label use rates; and (3) PRZM/EXAMS scenario site 

vulnerability was at the high-end for the crop and carbofuran use combination. These 

crop scenarios are outlined in Table 15 below. 

Table 15. Estimated Environmental Concentrations (μg ai/L)* of Carbofuran in Surface 

Water for Selected Use Patterns 

Using Minimum Rate Using Maximum Rate 

Crop/Location Acute 21-day Avg 60-day 

Avg Acute 21-day Avg 60-day Avg 

Alfalfa, California 0.7 0.6 0.4 5.2 4.5 3.0 

Alfalfa, Pennsylvania 0.7 0.6 0.4 5.7 4.6 3.0 

Corn, Illinois 17 14 9.4 25 20 17 

Cotton, Mississippi 10 7.9 5.5 11 8.2 5.7 

Grape, California 0.31 0.24 0.15 7.0 5.4 3.5 

Potato, Maine 3.6 2.9 2.0 26 21 14 

Potato, Idaho 4.5 3.4 2.2 6.7 5.1 3.3 

Sorghum, Texas 36 27 18 36 27 19 

Tobacco, North Carolina -- -- -- 10 7.7 5.0 

* EEC values represent the 1-in-10 year maximum concentration for the designated time interval. 

 i) Freshwater and Estuarine/Marine Fish 

 Carbofuran is very highly toxic to freshwater and estuarine/marine fish on an 

acute basis. Chronic toxicity testing with freshwater fish revealed larval survival as the 

most sensitive endpoint (NOAEC = 24.8 ppb a.i., LOAEC = 56.7 ppb a.i.). The 

available chronic test showed estuarine/marine fish were more sensitive than fresh water 

fish with embryo hatching as the most sensitive endpoint (NOAEC = 2.6 ppb a.i., 

LOAEC = 6.0 ppb a.i.). Table 16 summarizes the data that support the toxicity endpoints 

used in assessing the risks to fish. 

Table 16. Summary of Measurement Endpoint Values Used to Calculate Screening 

Level RQs for Fish 

Assessment Endpoint Test Species 

(Citation) Endpoint Toxicity Category Affected Endpoints 

Freshwater fish acute 

effects 

Bluegill sunfish (Lepomis 

macrochirus) 

(MRID 400980-01) 

LC50 = 88 Very highly 

toxic NA 

Freshwater fish chronic 

effects 

Rainbow trout 

(Oncorhynchus mykiss) 

(Acc. GEOCAR08) 

NOAEC = 

5.7 ppb a.i. NCa Larval survival, 

scoliosis 

Estuarine/marine fish 

acute effects 

Atlantic silverside (Menidia 

menidia) 

(Acc. 260899) 

LC50 = 33 Very highly 

toxic NA 

Estuarine/marine fish 

chronic effects 

Sheepshead minnow 

(Cyprindodon varigatus) 

(MRID 432505-01) 

NOAEC = 

2.6 ppb a.i. NCa Embryo hatching 

a Not characterized 

According to the deterministic assessment, carbofuran is not expected to reach 

surface water concentrations high enough to exceed the acute risk LOC for any crop 

25
application for freshwater fish. The chronic risk LOC is exceeded; however, for use on 

corn, sorghum, and potatoes. For estuarine/marine fish, there were acute and chronic 

LOC exceedences resulting from all uses. 

Table 17. Acute and Chronic RQ Ranges for Fish at Maximum and Minimum 

Application Rates 

Freshwater Estuarine/Marine Crop Acute Chronic Acute Chronic 

Alfalfa 0.01-0.06 0.07-0.53 0.02-0.17 0.15-1.2 

Corn 0.19-0.28 1.6-3.0 0.52-0.76 3.6-6.5 

Cotton 0.11-0.13 0.96-1.0 0.3-0.33 2.1-2.2 

Grapes 0.01-0.08 0.03-0.61 0.01-2.1 0.06-1.3 

Potatoes 0.04-0.3 0.35-2.5 0.11-0.79 0.77-5.4 

Sorghum 0.41 3.2-3.3 1.1 6.9-7.3 

Tobacco 0.11 0.88 0.3 1.9 

 Results of the refined probabilistic assessment show that for all uses of carbofuran 

modeled for surface water, at least 95% of exposed freshwater fish species will 

experience less than 0.5% mortality for any given use. Reproductive effect levels for the 

most sensitive freshwater species, bluegill sunfish, are exceeded in at least 4% 

(approximately 1 out of 25 years) of application years for all crops and up to 89% of 

application years (approximately 9 out of 10 years) for use on corn. 

 

 For exposed Atlantic silverside fish (estuarine), use on corn and sorghum is 

estimated in modeled surface waters to, on average, result in greater than 18% mortality. 

However, for the other crop uses modeled, the results indicated no demonstrable 

mortality (<1 case of mortality in a million) for the minimum application rate on cotton to 

9% mortality for the maximum application to potatoes. 

 ii) Freshwater and Estuarine/Marine Invertebrates 

 Carbofuran is considered to be very highly toxic to freshwater and 

estuarine/marine invertebrates on an acute basis. Table 18 summarizes the data that 

support the toxicity endpoints used in assessing the risks to invertebrates. 

Table 18. Summary of Measurement Endpoint Values Used to Calculate Screening 

Level RQs for Aquatic Invertebrates 

Study Type Test Species 

(Citation) Endpoint Toxicity Category 

Affected 

Endpoints 

Freshwater invertebrate 

acute effects 

Water flea (Ceriodaphnia 

dubia) 

(Bailey et al., 1996) 

EC50 = 2.23 Very highly 

toxic Mortality 

Freshwater invertebrate 

chronic effects 

 (Daphnia magna and 

Ceriodaphnia dubia)

(Acc. 262093, GEOCAR10) 

ENEC 

0.75 

Not 

classified Reproduction 

26
Study Type Test Species 

(Citation) Endpoint Toxicity Category 

Affected 

Endpoints 

Estuarine/marine 

invertebrate acute effects 

Pink shrimp 

(Penaeus duorarum) 

(MRID 40228401) 

LC50 = 4.6 Very highly 

toxic Mortality 

Estuarine/marine 

invertebrate chronic 

effects 

Mysid shrimp 

(Americanysis bahia) 

(MRID 40536001) 

NOAEC = 

0.4 

Not 

classified Reproduction 

ENEC = Estimated No Effect Concentration 

 According to the deterministic assessment, carbofuran is not expected to reach 

surface water concentrations high enough to exceed the acute risk LOC or chronic risk 

LOC for freshwater invertebrates at minimum label rates for alfalfa and grapes. All other 

uses exceed the acute and chronic risk LOCs. For estuarine/marine invertebrates, the 

acute LOC was exceeded for saltwater fish for corn, potatoes, and sorghum uses, with the 

chronic LOC exceeded for all uses except at minimum application rates to alfalfa and 

grapes. 

Table 19. Acute and Chronic RQ Ranges for Invertebrates at Maximum and Minimum 

Application Rates 

Freshwater Estuarine/Marine Crop Acute Chronic Acute Chronic 

Alfalfa 0.31-2.6 0.8-6.1 0.15-1.2 1.5-12 

Corn 7.6-11 19-27 3.7-5.4 35-50 

Cotton 4.5-4.9 11 2.2-2.4 20-21 

Grapes 0.14-3.1 0.32-7.2 0.07-1.5 0.6-14 

Potatoes 1.6-12 3.9-28 0.78-5.7 7.2-53 

Sorghum 16 36 7.8 68 

Tobacco 4.5 11 2.2 19 

 In the refined probabilistic assessment, for modeled surface water, on average at 

least 5% of exposed freshwater invertebrate species were estimated to experience greater 

than 80% mortality and 25% of exposed freshwater species were estimated to have up to 

28% mortality for most uses of carbofuran, except for the Idaho and Washington Special 

Local Need (SLN) labeled rate on potatoes. Reproductive effect levels for C. dubia, the 

most sensitive freshwater invertebrate tested, were exceeded for nearly all uses, except 

cotton and the Idaho and Washington SLN labeled rate for potatoes, in all application 

years. The frequency of exceedences of the reproductive level was in the range of 70% 

for cotton and 43% for the Idaho and Washington SLN labeled rates. 

 For exposed pink shrimp, results of the refined assessment show essentially 100% 

mortality in modeled surface waters for use on corn and sorghum and greater than 83% 

mortality for use on potatoes. For the other application rates, methods and crops, the 

median percent mortality estimate for exposed pink shrimp populations ranges from 0.6% 

for the minimum application rate for cotton to 69% for the maximum application rate on 

grapes. 

27
Aquatic Field Data and Incidents

 In comparison to birds, relatively few incidents with fish and shellfish have been 

reported, and only limited monitoring has been conducted in association with the use of 

liquid carbofuran in aquatic habitats. In California, elevated levels of carbofuran in the 

Colusa Basin resulted in the listing of that area for Total Maximum Daily Load (TMDL) 

development. Eight incidents have been attributed to carbofuran use according to the 

label directions. Two of these incidents were associated with flowable carbofuran 

formulations, two with granular, and for the remainder, the formulation was not reported. 

More than 600 fish were killed in two ponds following use of liquid carbofuran spray on 

alfalfa in Clark County, Missouri, following a rain event in May 1981. Another incident, 

involving liquid carbofuran chemigation to grapes, occurred in San Joaquin County, 

California. In that incident (November 1991), more than 3,000 fish, 4,000 crayfish and 

frogs, and 5,000 other large aquatic invertebrates were killed in a creek near a vineyard. 

 3. Risk Characterization 

 The Agency has taken action in the past for avian risks from the granular 

formulation of carbofuran. To arrive at the current decision, the Agency used multiple 

lines of evidence, including refined probabilistic risk estimates, to conclude that the 

flowable formulation of carbofuran also poses significant acute risks to birds. In 

addition, based on the previously conducted risk assessments, and extrapolating from the 

assessments on the flowable formulation, EPA continues to believe that the granular 

formulation poses significant acute risks to birds. 

 The terrestrial risk assessments also show acute and chronic risks to mammals and 

chronic risks to birds. The aquatic assessments show some risks to fish and significant 

risks to aquatic invertebrates. There is lower confidence in the estuarine/marine aquatic 

risk conclusions relative to the other non-target organism assessments. 

 Carbofuran has often been misused to poison predators, including foxes, coyotes, 

wolves, and bears. The technical registrant has conducted an educational/stewardship 

program to deter misuse, but intentional baiting continues to be a concern with 

carbofuran. 

 Many carbofuran incidents which have been classified as “misuse” or “off-label” 

appear to be the result of mistakes in application, rather than deliberate misuse. Given 

the high toxicity of carbofuran, the margin of error is small so that a minor mistake can 

have serious consequences. 

 There is high confidence in these risk assessment findings since the deterministic 

and probabilistic risk assessments, as well as controlled field studies and incident 

reviews, all support the same conclusion: that carbofuran use poses potentially serious 

risks to non-target organisms. 

28
 4. Endangered Species Considerations 

The Agency’s preliminary risk assessment for endangered species indicates that 

RQs exceed the endangered species LOC for terrestrial and aquatic animals, indicating 

the potential for direct effects. Further, potential indirect effects to any species dependent 

upon a species that experiences effects from use of carbofuran can not be precluded based 

on the screening level ecological risk assessment. These findings are based solely on 

EPA’s screening level assessment and, because they do not take into account such factors 

as whether the species would be expected to be exposed to carbofuran, do not constitute 

“may affect” findings under the Endangered Species Act. 

 EPA is currently engaging in informal consultations with the Fish and Wildlife 

Service and the National Marine Fisheries Service, which is a part of the National 

Oceanic and Atmospheric Administration. This means that the Agencies are working 

together to conduct a full endangered species assessment for carbofuran, which is 

separate from this IRED. The likelihood of potential impacts to endangered species will 

need to be assessed for all counties in which: 1) crops registered for carbofuran use are 

grown; and 2) contain habitat for at least one listed species. 

IV. Interim Risk Management, Reregistration, and Tolerance Reassessment 

Decision 

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 reregistration. The Agency has previously identified and 

required the submission of the generic (technical or manufacturing-use grade) data 

required to support reregistration of products containing carbofuran as an active 

ingredient. 

The Agency has completed its review of submitted data and its assessment of the 

ecological, occupational, and dietary risks associated with the use of pesticide products 

containing the active ingredient carbofuran. Based on these data, the Agency has 

sufficient information on the human health and ecological effects of carbofuran to make 

its interim decisions as part of the tolerance reassessment process under FFDCA, as 

amended by FQPA, and the reregistration process under FIFRA, pending completion of 

the cumulative assessment of the N-methyl carbamate class of pesticides, of which 

carbofuran is a member. Additional mitigation may be necessary after this cumulative 

assessment is completed. 

The Agency has determined that all products containing carbofuran are not 

eligible for reregistration. Some uses have been identified as providing moderate benefits 

to growers, and those will be subject to a phase-out. 

29
B. Public Comments and Responses 

Through the Agency’s public participation process, EPA worked extensively with 

stakeholders and the public to reach the regulatory decisions for carbofuran. During the 

most recent public comment period on the risk assessments, which closed on May 22, 

2006, the Agency received many sets of comments from stakeholders. These included 

comments from the technical registrant, growers, the Fish and Wildlife Service, the 

National Agricultural Aviation Association, the Natural Resource Defense Council, and 

others. The comments included some urging the Agency to regulate carbofuran more 

stringently, as well as some requesting that the Agency retain certain uses. These 

comments, in their entirety, are available in the public docket (docket # OPP-2005-0162) 

at http://www.regulations.gov. EPA has prepared responses to these comments and they 

are posted in the docket, along with this IRED. The Agency also received comments 

after the comment period closed, including 23 additional grower comments in support of 

carbofuran and several thousand comments from private citizens requesting that the 

Agency cancel use of carbofuran. 

 In addition, EPA worked with USDA to solicit input from the grower community 

on the importance of carbofuran use for those crops with < 1% of cropped area treated 

with carbofuran. EPA received many comments from growers through this process. 

EPA has considered these comments, and will be responding to them through a formal 

response to comments memo, which will be placed in the public docket, along with this 

document.

The IRED and technical supporting documents for carbofuran are also available 

to the public through EPA’s electronic public docket and comment system, the Federal 

Docket Management System (FDMS), under [legacy] docket identification (ID) number 

EPA-HQ-OPP-2005-0162. In addition, the carbofuran IRED may be downloaded or 

viewed through the Agency’s website at 

http://www.epa.gov/pesticides/reregistration/status.htm.

C. Regulatory Position Under FIFRA and FFDCA

 The following is a summary of the rationale for managing risks associated with 

the use of carbofuran. Under FIFRA, the Agency is proposing to cancel all uses of 

carbofuran, due to ecological and occupational risks of concern (See the ecological and 

human health risk assessments for carbofuran). In addition, there are dietary risks of 

concern from some crops. See the first listing of crops under Mitigation Summary below. 

Benefits are low to moderate for all of these uses, and do not outweigh the risks. 

There are several uses for which residues do not pose dietary risks of concern and

which have moderate benefits to growers [artichokes, chile peppers in the Southwestern 

U.S., cucurbits (granular formulation only), spinach grown for seed, sunflowers, and pine 

seedlings in the Southeastern U.S.]. For these uses, EPA is allowing a 4-year phase-out 

in order to allow time for new alternatives to become available to growers. In addition, 

import tolerances will be maintained for bananas, coffee, rice, and sugarcane. Dietary 

30
risks from the imported foods are below the level of concern for these crops when 

considered together. For bananas, sugarcane, and coffee, however, benefits to U.S. 

growers are low when compared to ecological and occupational risks from domestic uses 

of these crops. Carbofuran is no longer registered for use on rice in the U.S. Dietary 

risks of phase-out crops plus these imported foods are below the Agency’s level of 

concern. 

 1. Mitigation Summary 

• Cancellation based on high ecological and worker risks and low 

economic benefits for growers 

Sorghum Alfalfa Sweet corn 

Cotton Grapes Field corn and popcorn 

Wheat Potatoes Bananas/plantains 

Cucurbits (flowable) Oats Soybeans 

Barley Tobacco Fallow/idle land 

Sugarcane Ornamentals Sugar beets 

Peppers (except chile) 

• 4-year Phase-out for the crops which have moderate benefits to 

growers.

Artichokes, chile peppers in the Southwestern U.S., cucurbits (granular 

formulation only), sunflowers, spinach grown for seed, and pine seedlings 

in the Southeastern U.S. 

2. Regulatory Rationale 

 The Agency evaluated the relationship of risks and benefits for all carbofuran uses 

on a use-by-use basis. These analyses show high ecological and occupational risks for all 

carbofuran uses. In addition, as discussed below, the benefits associated with most crops 

are low, although some uses have moderate benefits. Based on the assessment of 

ecological and human health risks associated with carbofuran uses, the Agency has 

determined that all uses of carbofuran do not meet the standard for continued registration 

under FIFRA. 

The Agency has identified a few niche uses, however, for which there are 

moderate benefits to growers. In the short term, at least, these moderate benefits would 

justify retaining uses for a limited time. The Agency believes that there are not enough 

affordable alternatives to provide effective pest control for artichokes, chile peppers 

grown in the Southwestern U.S., cucurbits (granular formulation only), spinach grown for 

seed, pine seedlings grown in the Southeastern U.S., and sunflowers. EPA believes, 

however, that with the development of newer chemistries and other alternative pest 

control practices, the benefits of these uses will decrease. Therefore, a phase-out period 

of four years, with some additional restrictions to ensure the risks are reduced to 

31
acceptable levels, is appropriate, given the current risk/benefit analyses. Cancellation of 

all but the phase-out crops reduces 98% of the total annual carbofuran use. 

Additionally, some uses of carbofuran result in dietary risks above the Agency’s 

level of concern under FFDCA. Therefore, EPA has determined that, in addition to 

significant occupational and ecological risks, these uses would not be eligible for 

reregistration because the Agency cannot determine that the tolerances for such crops 

meet the FQPA safety standard, based on the contribution of these uses to the aggregate 

risks for carbofuran. The uses which do not fit within the dietary risk cup based on food 

residues alone from the individual commodity are: sweet corn, potatoes, and flowable 

carbofuran on the following cucurbits: pumpkins, squash (summer and winter), casaba 

melons, cucumbers, honeydew, and watermelon. Additionally, the dietary contribution 

of carbofuran in milk exceeds the Agency’s level of concern for infants and children with 

corn and alfalfa being cattle feed items which are assumed to be the primary sources of 

residues in milk. The risk estimates for cucurbits are based on both granular and 

flowable carbofuran treatments at current usage levels. Estimated dietary risks based on 

the granular use only, with the current production cap of 2,500 pounds per year, are 

below the level of concern. 

The Agency also has dietary risk concerns posed by exposure from drinking water 

sources. Since food alone completely fills the risk cup (i.e. exposure is greater than 

100% of the aPAD), any level of carbofuran residues in drinking water would result in 

additional risks of concern. Modeling estimates of residues in surface and ground water 

from all uses result in residue values above EPA’s level of concern. In addition, recent 

USGS NAWQA monitoring data show multiple detections at low concentrations. The 

Agency recognizes that shallow, slightly acidic groundwater sources are the most 

vulnerable to carbofuran contamination. Such groundwater sources are located primarily 

in portions of the Southeast and the east coast of the United States. The uses for which 

EPA is not proposing immediate cancellation are those that are not expected to 

significantly contribute to groundwater contamination since they are limited in spatial 

extent of production (artichokes, chile peppers), applied in arid regions or in areas where 

pH is higher (chile peppers, sunflowers), or limited due to method of treatment (pine 

seedling dip). Cancellation of all other uses will reduce the amount of carbofuran applied 

from approximately 1 million pounds annually to approximately 19,500 pounds of use 

remaining for four years. 

Additionally, because dietary risks from use of flowable carbofuran on cucurbits 

alone exceed the risk cup based on PDP food residue monitoring data and a high percent 

crop treated, the four year phase-out for cucurbits applies only to granular carbofuran. 

The Agency will maintain import tolerances for bananas, coffee, rice, and 

sugarcane. Dietary risks from the import tolerances are below the Agency’s level of 

concern when considered together with the food residues from the phase-out crops (56 % 

of the aPAD). There are currently domestic uses for bananas, sugarcane, and coffee, but 

they are ineligible for reregistration based on low benefits and ecological and 

occupational risks of concern. 

32
 3. Significance of Use 

 Carbofuran is a systemic insecticide which is used to control pests on a variety of 

fruit, vegetable, and field crops. Use has been declining in recent years and is now 

mostly limited to niche uses. Adequate alternatives exist for all crops except artichokes, 

chile peppers in the Southwestern U.S., cucurbits, spinach grown for seed, sunflowers, 

and pine seedlings in the Southeastern U.S. Use on cucurbits will be limited to the 

granular formulation based on dietary risks. 

 During the two public comment periods on the carbofuran risk assessments, the 

Agency received many grower comments in support of retaining carbofuran use for 

various crops. 

 EPA divided uses into two groups based on percent crop treated. If a low 

percentage of a crop is treated, the Agency makes the preliminary assumption that the 

significance of use on that crop is also low. For these crops, the Agency consulted with 

the USDA Office of Pest Management Policy (OPMP) to determine whether there were 

niche uses which should be considered in any mitigation plan. The nineteen use sites in 

this category are: bananas, barley, coffee, cotton, cranberry, flax, grapes, oats, 

ornamentals, pine forests, plantains, sorghum, soybeans, spinach grown for seed, sugar 

beets, sugarcane, sunflowers, tobacco, and wheat. OPMP received comments from the 

Integrated Pest Management Centers on carbofuran use on these crops. In general, these 

comments supported the conclusion that minimal impacts would be expected if 

carbofuran were no longer available for those crops with less than one percent crop 

treated. 

 For those use sites with either greater than 1% crop treated or at least 100,000 lbs 

carbofuran applied each year, the Agency assumed that the higher use frequency implied 

significance of use. For these sites, the Agency examined carbofuran use patterns, 

available alternatives, and the impacts of cancellation to growers. Analyses were 

conducted for artichokes, potatoes, field corn, alfalfa, cucurbits, and peppers. Through 

conducting these in-depth benefits analyses, the Agency was able to determine that, with 

the exception of artichokes, certain cucurbits, and chile peppers, minimal impacts would 

also be expected if carbofuran were no longer available for use on those crops with 

greater than 1% crop treated or 100,000 lbs applied annually. The Agency’s benefits 

assessments will be posted to the carbofuran docket, along with this IRED. 

In addition, after the most recent public comment period closed, the Agency 

received some new information from corn growers regarding the use of carbofuran as a 

rescue treatment for corn rootworm damage. The Agency therefore took particular care 

to examine potential benefits from this use. Corn rootworm pressure has been increasing 

for a variety of reasons, including rotation resistance (i.e., rootworms have become 

resistant to the control offered by rotating soybeans with corn) and the uncertain 

performance of seed treatments under high rootworm pressure. In addition, increasingly 

higher production of corn and continuous corn production are being practiced due to 

33
increasing demand for ethanol. When high rootworm pressure is likely, most growers 

will use at-plant insecticides, such as tefluthrin, or plant genetically modified Bt corn. 

When low to moderate rootworm pressure is likely, growers will typically rely on seed 

treatments and survey for root damage instead of rootworm larvae. Clothianidin acts as a 

feeding depressant, and thus growers sampling soil in corn fields for larvae may 

misinterpret the presence of moribund (inactive) larvae as a control failure. Extension 

entomologists have recommended that growers look for root pruning and damage (rather 

than rootworm larvae) to assess the success of seed treatments. In limited circumstances, 

some growers may experience yield losses as a result of rootworm damage and have used 

carbofuran as a rescue treatment over the corn canopy. However, based on information 

from a variety of state extension publications and experts and the general lack of 

supporting data, the Agency believes that rescue treatments of carbofuran applied over 

the canopy to control corn rootworm damage perform erratically and are not a sound 

investment for growers. 

 There are several crops for which the Agency believes there are moderate 

benefits to growers: artichokes, chile peppers in the Southwestern U.S., cucurbits, 

spinach grown for seed, sunflowers, and pine seedlings. Some moderate benefits have 

also been identified for sweet corn for control of the wheat curl mite, which transmits 

High Plains disease. However, the Agency is not planning to allow a phase-out of this 

use due to the fact that there are dietary risks of concern. 

Flowable formulation

• Growers apply carbofuran to artichokes for control of cribrate weevils, proba 

bugs, and artichoke aphids. Effective alternatives exist for aphids; however, the 

alternatives for cribrate weevil and proba bugs are not as effective (see 

Alternatives Assessment for Carbofuran on Artichoke, D. Brassard and S. 

Smearman, July 14, 2006). 

• Carbofuran is used on chile peppers for control of flea beetles, thrips, and 

leafhoppers, as well as the green peach aphid in Arizona and Texas. There are 

adequate alternatives available; however, EPA acknowledges that some growers 

would face higher production costs without the availability of carbofuran. In 

addition, use of carbofuran on chile peppers is limited to Arizona, New Mexico, 

and Texas (see Impact Assessment for Carbofuran on Peppers, N. Zinn and E. 

Rim, June 28, 2006). 

• Carbofuran is used on sunflowers to control stem weevils. Alternatives are 

available for the post plant foliar use, but not for the soil at-plant use. There are 

also a number of natural enemies available; however, it is unclear whether they 

can achieve adequate control of stem weevils (see Carbofuran Response to 

Comments and Alternatives Analysis for Crops with Low Usage, D. Brassard et 

al, July 7, 2006). 

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• Only limited alternatives are available for control of pales and pitch weevil in 

pine seedlings (see Carbofuran Response to Comments and Alternatives Analysis 

for Crops with Low Usage, D. Brassard et al, July 7, 2006). 

Granular formulation

 The Agency and the technical registrant reached an agreement in 1991 that sales 

of granular carbofuran would be limited to 2,500 lbs a year. This agreement was based 

on the ecological risks of concern posed by use of carbofuran, and phase-out use is 

limited to cucurbits, spinach for seed, and pine seedlings only. 

• Only limited alternatives are available for control of pales and pitch weevil in 

pine seedlings (see Carbofuran Response to Comments and Alternatives Analysis 

for Crops with Low Usage, D. Brassard et al, July 7, 2006). 

• In spinach grown for seed, springtails and European craneflies can cause yield 

losses of 100%, and carbofuran is the only pesticide available for control of these 

pests (see Carbofuran Response to Comments and Alternatives Analysis for Crops 

with Low Usage, D. Brassard et al, July 7, 2006). 

• There are adequate alternatives available for cucurbits; however, EPA 

acknowledges that some growers would face higher production costs without the 

availability of carbofuran. [see Impact Assessment for Carbofuran on Cucurbits 

(Cucumbers, Pumpkins, Squash, and Watermelon), N. Zinn and E. Rim, June 14, 

2006.] 

 D. Endangered Species Considerations 

 Endangered species acute and chronic LOCs are exceeded for all groups of 

terrestrial animals (birds, mammals, and invertebrates) for all uses and for all rates of 

flowable and granular formulations of carbofuran, indicating a potential for direct effects 

on listed species. Endangered species acute and chronic LOC are also exceeded for all 

groups of aquatic organisms for most uses of flowable and the limited remaining granular 

formulations of carbofuran. Exceedences of the LOCs indicate a potential for effects to 

listed species. 

 The Agency has developed the Endangered Species Protection Program to 

identify pesticides whose use may cause adverse impacts on endangered and threatened 

species, and to implement mitigation measures that address these impacts. The 

Endangered Species Act (ESA) requires federal agencies to ensure that their actions are 

not likely to jeopardize listed species or adversely modify designated critical habitat. To 

analyze the potential of registered pesticide uses that may affect any particular species, 

EPA uses basic toxicity and exposure data developed for the REDs/IREDs and considers 

these data in relation to individual species and their locations by evaluating important 

ecological parameters, pesticide use information, geographic relationship between 

specific pesticide uses and species locations, and biological requirements and behavioral 

35
aspects of the particular species, as part of a refined species-specific analysis. 

Carbofuran is one of the first chemicals for which the Agency has begun a full, speciesspecific endangered species analysis. The Agency is currently participating in informal 

consultations with the Fish and Wildlife Service and the National Marine Fisheries 

Service within the National Oceanic and Atmospheric Administration. The Agencies 

hold monthly meetings to exchange information. This species-specific analysis is being 

completed separately from this IRED, and will take into consideration any regulatory 

changes recommended in this IRED that are being implemented at that time. 

 Following this future species-specific analysis, a determination that there is a 

likelihood of potential impact to a listed species or its critical habitat may result in: 

limitations on the use of carbofuran, other measures to mitigate any potential impact, or 

consultations with the Fish and Wildlife Service or the National Marine Fisheries Service 

as necessary. If the Agency determines use of carbofuran “may affect” listed species or 

their designated critical habitat, EPA will employ the provisions in the Services 

regulations (50 CFR Part 402). Until that species-specific analysis is completed, the risk 

mitigation measures being implemented through this IRED will reduce the likelihood that 

endangered and threatened species may be exposed to carbofuran at levels of concern. 

EPA is not requiring specific carbofuran label language at the present time relative to 

threatened and endangered species. If, in the future, specific measures are necessary for 

the protection of listed species, the Agency will implement them through the Endangered 

Species Protection Program. 

E. Food Quality Protection Act Findings and Tolerance Summary 

 1. FQPA 

 a. Risk Cup Determination

 As part of the FQPA tolerance reassessment process, EPA assessed the risks 

associated with this N-methyl carbamate (NMC). The assessment is for this individual 

NMC, and does not attempt to fully reassess these tolerances as required under FQPA. 

FQPA requires the Agency to evaluate food tolerances on the basis of cumulative risk 

from substances sharing a common mechanism of toxicity, such as the toxicity expressed 

by the NMCs through a common biochemical interaction with the cholinesterase enzyme. 

The preliminary cumulative risk assessment for the NMC Cumulative Assessment Group, 

which includes carbofuran, was released in July 2005. The revised cumulative risk 

assessment is currently being developed and will be completed during 2006. The results 

of this NMC cumulative assessment, as well as the single chemical carbofuran 

assessment, will be considered in the final tolerance reassessment decision for 

carbofuran. 

 EPA has determined that risk from food (dietary sources only) exposure to 

carbofuran exceeds its own “risk cup” (490% of the aPAD for children). Therefore, 

residues in drinking water will be of concern. Exposure from the crops allowed for fouryear phase-out plus the four crops maintained as import tolerances is estimated at 56% of 

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the aPAD for infants, the population subgroup with the highest exposure. Residues in 

water are expected to decline when use ceases. 

 b. Endocrine Disruptor 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 Disruptor 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 

that EPA include evaluations of potential effects in wildlife. For pesticides, EPA will use 

FIFRA and, to the extent that effects in wildlife may help determine whether a substance 

may have an effect in humans, FFDCA authority to require the wildlife evaluations. As 

the science develops and resources allow, screening of additional hormone systems may 

be added to the Endocrine Disruptor Screening Program (EDSP). 

 2. Interim Tolerance Summary 

 The Agency is proposing to cancel all uses of carbofuran based on ecological, 

occupational, and dietary risks of concern, and to revoke all tolerances, with the 

exception of bananas, rice, sugarcane, and coffee. These tolerances will be maintained 

for import purposes only. Several uses were identified as having moderate benefits to 

growers, and the Agency is proposing to implement a 4-year phase-out for those crops. 

Therefore EPA is proposing to delay the effective date of revocation of the tolerances for 

artichokes, corn, peppers, and sunflowers until 2010. All other tolerances will be 

proposed for revocation following completion of this IRED. 

 A summary of the dietary aggregate assessment for food and drinking water that 

supports the finding that the (1) time-limited retention of the uses to be phased out and 

(2) retention of the import tolerances meets the FQPA safety standard is presented in the 

Regulatory Rationale section of this document, and in the carbofuran reregistration 

docket (EPA-HQ-OPP-2005-0162). 

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Table 20. Interim Tolerance Summary for Carbofuran 

Commodity Current Tolerance, 

ppm 

Tolerance 

Reassessment, ppm 

Comment/ 

[Correct Commodity Definition]

Tolerances Listed Under 40 CFR §180.254 (a)

Alfalfa , fresh; alfalfa, hay; 

barley, grain; barley, straw; 

beet, sugar; beet, sugar, 

tops; corn, forage; corn, 

fresh (including sweet corn) 

(K+CWHR); corn, grain 

(including popcorn); corn, 

stover; cotton, undelinted 

seed; cranberry; grape; 

grape, raisin; milk; oat, 

grain; oat, straw; potato, 

raisins, waste; sorghum, 

fodder; sorghum, forage; 

sorghum, grain; soybean; 

soybean, forage; soybean, 

hay; strawberry; wheat, 

grain; wheat, straw 

10 (5) Revoke 

Banana 0.1 0.1 Maintained for import purposes. 

Coffee bean 0.1 0.1 [Coffee, green bean] Maintained for 

import purposes. 

Cucumber 0.4 (0.2) 

Melons 0.4 (0.2) 

Pumpkin 0.8 (0.6) 

Squash 0.8 (0.6) 

Revoke 

(Maintain at current 

level until expiration in 

2010.) 

Revoke individual tolerances and 

establish a crop group tolerance for 

Cucurbit Vegetables Group 9. 

Tolerance will expire in 2010. 

Pepper 1 (0.2) 

Revoke 

(Maintain at current 

level until expiration in 

2010.) 

[pepper, nonbell] 

Tolerance will expire in 2010. 

Rice, grain 0.2 0.2 No Section 3 registrations. 

Maintained for import purposes. 

Sugarcane, cane 0.1 0.2 Maintained for import purposes. 

Sunflower, seed 1.0 (0.5) 

Revoke 

(Maintain at current 

level until expiration in 

2010.) 

Tolerance will expire in 2010. 

Tolerances Listed Under 40 CFR §180.254 (c)

Artichoke, globe 0.4 (0.2) 

Revoke 

(Maintain at current 

level until expiration in 

2010.) 

Tolerance will expire in 2010. 

(Number in parentheses reflects the ppm level that residues of carbamates may not exceed.) 

 

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