UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

OFFICE OF 

PREVENTION, PESTICIDES

AND TOXIC SUBSTANCES

CERTIFIED MAIL

Dear Registrant:

I am pleased to announce that the Environmental Protection Agency has completed its

reregistration eligibility review and decisions on the pesticide chemical case paraquat

dichloride which includes the active ingredient 1,1'-dimethyl-4,4'-bipyridinium dichloride. 

The enclosed Reregistration Eligibility Decision (RED), which was signed on 9/30/96,

contains the Agency's evaluation of the data base of these chemicals, its conclusions of the

potential human health and environmental risks of the current product uses, and its decisions

and conditions under which these uses and products will be eligible for reregistration. The

RED includes the data and labeling requirements for products for reregistration. It may also

include requirements for additional data (generic) on the active ingredients to confirm the risk

assessments.

To assist you with a proper response, read the enclosed document entitled "Summary

of Instructions for Responding to the RED." This summary also refers to other enclosed

documents which include further instructions. You must follow all instructions and submit

complete and timely responses. The first set of required responses is due 90 days from the

date of this letter. The second set of required responses is due 8 months from the date of

this letter. Complete and timely responses will avoid the Agency taking the enforcement

action of suspension against your products.

Please note that the Food Quality Protection Act of 1996 ("FQPA") became effective

on August 3, 1996, amending portions of both the pesticide law (FIFRA) and the food and

drug law (FFDCA). This RED takes into account, to the extent currently possible, the new

safety standard set by FQPA for establishing and reassessing tolerances. However, it should

also be noted that in continuing to make reregistration determinations during the early stages

of FQPA implementation, EPA recognizes that it will be necessary to make decisions relating

to FQPA before the implementation process is complete. In making these early case-by-case

decisions, EPA does not intend to set broad precedents for the application of FQPA. Rather,

these early determinations will be made on a case-by-case basis and will not bind EPA as it

proceeds with further policy development and any rulemaking that may be required.
If EPA determines, as a result of this later implementation process, that any of the

determinations described in this RED are no longer appropriate, the Agency will pursue

whatever action may be appropriate, including but not limited to reconsideration of any

portion of this RED.

If you have questions on the product specific data requirements or wish to meet with

the Agency, please contact the Special Review and Reregistration Division representative

Venus Eagle at (703) 308-8045. Address any questions on required generic data to the

Special Review and Reregistration Division representative, Ruby Whiters at (703) 308-8079.

Sincerely yours,

Lois Rossi, Division Director

Special Review and

 Reregistration Division

Enclosures
SUMMARY OF INSTRUCTIONS FOR RESPONDING TO

THE REREGISTRATION ELIGIBILITY DECISION (RED)

1. DATA CALL-IN (DCI) OR "90-DAY RESPONSE"--If generic data are required for

reregistration, a DCI letter will be enclosed describing such data. If product specific data are

required, a DCI letter will be enclosed listing such requirements. If both generic and

product specific data are required, a combined Generic and Product Specific DCI letter will

be enclosed describing such data. However, if you are an end-use product registrant only and

have been granted a generic data exemption (GDE) by EPA, you are being sent only the

product specific response forms (2 forms) with the RED. Registrants responsible for generic

data are being sent response forms for both generic and product specific data requirements (4

forms). You must submit the appropriate response forms (following the instructions

provided) within 90 days of the receipt of this RED/DCI letter; otherwise, your product

may be suspended.

2. TIME EXTENSIONS AND DATA WAIVER REQUESTS--No time extension requests

will be granted for the 90-day response. Time extension requests may be submitted only with

respect to actual data submissions. Requests for time extensions for product specific data should

be submitted in the 90-day response. Requests for data waivers must be submitted as part of the

90-day response. All data waiver and time extension requests must be accompanied by a full

justification. All waivers and time extensions must be granted by EPA in order to go into effect.

3. APPLICATION FOR REREGISTRATION OR "8-MONTH RESPONSE"--You must

submit the following items for each product within eight months of the date of this letter

(RED issuance date).

a. Application for Reregistration (EPA Form 8570-1). Use only an original

application form. Mark it "Application for Reregistration." Send your Application for

Reregistration (along with the other forms listed in b-e below) to the address listed in item 5.

b. Five copies of draft labeling which complies with the RED and current regulations

and requirements. Only make labeling changes which are required by the RED and current

regulations (40 CFR 156.10) and policies. Submit any other amendments (such as formulation

changes, or labeling changes not related to reregistration) separately. You may, but are not

required to, delete uses which the RED says are ineligible for reregistration. For further labeling

guidance, refer to the labeling section of the EPA publication "General Information on Applying

for Registration in the U.S., Second Edition, August 1992" (available from the National

Technical Information Service, publication #PB92-221811; telephone number 703-487-4650).

c. Generic or Product Specific Data. Submit all data in a format which complies with

PR Notice 86-5, and/or submit citations of data already submitted and give the EPA identifier

(MRID) numbers. Before citing these studies, you must make sure that they meet the

Agency's acceptance criteria (attached to the DCI).

d. Two copies of the Confidential Statement of Formula (CSF) for each basic and

each alternate formulation. The labeling and CSF which you submit for each product must

comply with P.R. Notice 91-2 by declaring the active ingredient as the nominal concentration. 

You have two options for submitting a CSF: (1) accept the standard certified limits (see 40 CFR

§158.175) or (2) provide certified limits that are supported by the analysis of five batches. If
you choose the second option, you must submit or cite the data for the five batches along with a

certification statement as described in 40 CFR §158.175(e). A copy of the CSF is enclosed;

follow the instructions on its back.

e. Certification With Respect to Data Compensation Requirements. Complete and

sign EPA form 8570-31 for each product. 

4. COMMENTS IN RESPONSE TO FEDERAL REGISTER NOTICE--Comments

pertaining to the content of the RED may be submitted to the address shown in the Federal

Register Notice which announces the availability of this RED.

5. WHERE TO SEND PRODUCT SPECIFIC DCI RESPONSES (90-DAY) AND

APPLICATIONS FOR REREGISTRATION (8-MONTH RESPONSES)

By U.S. Mail:

Document Processing Desk (RED-SRRD-PRB)

Office of Pesticide Programs (7504C)

 EPA, 401 M St. S.W.

Washington, D.C. 20460-0001

By express:

Document Processing Desk (RED-SRRD-PRB)

Office of Pesticide Programs (7504C) 

Room 266A, Crystal Mall 2 

1921 Jefferson Davis Hwy. 

Arlington, VA 22202

6. EPA'S REVIEWS--EPA will screen all submissions for completeness; those which are not

complete will be returned with a request for corrections. EPA will try to respond to data waiver

and time extension requests within 60 days. EPA will also try to respond to all 8-month

submissions with a final reregistration determination within 14 months after the RED has been

issued. 

ENVIRONMENTAL PROTECTION AGENCY

OFFICE OF PESTICIDE PROGRAMS

SPECIAL REVIEW AND REREGISTRATION DIVISION

REREGISTRATION ELIGIBILITY DECISION

Paraquat Dichloride

LIST A

CASE 0262
TABLE OF CONTENTS

PARAQUAT DICHLORIDE REREGISTRATION ELIGIBILITY DECISION TEAM i

ABSTRACT .............................................................. v

I. INTRODUCTION ................................................... 1

II. CASE OVERVIEW .................................................. 2

A. Chemical Overview ............................................. 2

B. Use Profile .................................................... 2

C. Estimated Usage of Pesticide ..................................... 4

D. Data Requirements ............................................. 9

E. Regulatory History ............................................. 9

III. SCIENCE ASSESSMENT ............................................ 10

A. Physical Chemistry Assessment .................................. 10

B. Human Health Assessment ...................................... 11

1. Toxicology Assessment ................................... 11

a. Acute Toxicity ..................................... 11

b. Subchronic Toxicity ................................ 13

c. Chronic Toxicity ................................... 15

d. Carcinogenicity ................................... 19

e. Developmental Toxicity ............................. 25

f. Reproductive Toxicity .............................. 28

g. Mutagenicity ...................................... 29

h. Metabolism ....................................... 32

i. Neurotoxicity ..................................... 33

j. Dermal Absorption ................................ 33

k. Poisoning Incidents ................................ 33

l. Toxicological Endpoints of Concern Identified for Use in 

Risk Assessment ................................... 34

2. Exposure Assessment .................................... 36

a. Registered Uses .................................... 36

b. Dietary Exposure .................................. 37

c. Occupational and Residential ........................ 45

3. Risk Assessment ......................................... 54

a. Dietary ........................................... 54

b. Occupational and Residential ........................ 55

4. Food Quality Protection Act Considerations ................. 57

a. Potential Risks to Infants and Children ................ 58

b. Aggregate Exposure/Risk ........................... 60

c. Cumulative Effects ................................. 61

C. Environmental Assessment ..................................... 62

1. Ecological Toxicity Data .................................. 62

a. Toxicity to Terrestrial Animals ....................... 62

(1) Birds, Acute and Subacute .................... 62
(2) Birds, Chronic ............................... 63

(3) Mammals ................................... 64

(4) Insects ..................................... 66

b. Toxicity to Aquatic Animals ......................... 67

c. Toxicity to Plants .................................. 69

2. Environmental Fate ...................................... 71

a. Environmental Fate Assessment ...................... 71

b. Environmental Fate, Chemistry, and Transport ......... 73

c. Water Resources .................................. 76

3. Exposure and Risk Characterization ........................ 77

a. Ecological Exposure and Risk Characterization ......... 77

IV. RISK MANAGEMENT AND REREGISTRATION DECISION ............ 93

A. Determination of Eligibility ..................................... 93

B. Determination of Eligibility Decision .............................. 93

1. Eligibility Decision ....................................... 93

2. Eligible and Ineligible Uses ............................... 94

C. Regulatory Position ............................................ 94

1. Food Quality Protection Act Findings ....................... 94

a. Determination of Safety for U.S. Population ............ 94

b. Determination of Safety for Infants and Children ....... 95

2. Tolerance Reassessment .................................. 96

a. CODEX Harmonization ........................... 108

3. Tolerance Revocations and Import Tolerances .............. 109

4. Summary of Risk Management Decisions ................... 110

a. Human Health ................................... 110

b. Environmental ................................... 112

5. Occupational/Residential Labeling Rationale ................ 116

V. ACTIONS REQUIRED OF REGISTRANTS ........................... 121

A. Manufacturing-Use Products ................................... 121

1. Additional Generic Data Requirements .................... 121

2. Labeling Requirements for Manufacturing-Use Products ..... 122

B. End-Use Products ............................................ 122

1. Additional Product-Specific Data Requirements ............. 122

2. Labeling Requirements for End-Use Products ............... 123

a. Application Rates and Label Deletions ............... 123

b. Hazard Statement ................................ 123

c. PPE/Engineering Control Requirements for Pesticide 

Handlers ........................................ 123

d. Products Intended Primarily for Occupational Use (WPS 

and nonWPS) .................................... 124

e. Products Intended Primarily for Occupational Use - 

Entry Restrictions and Labeling ..................... 125

f. Other Labeling Requirements ...................... 127

C. Spray Drift Labeling .......................................... 128

D. Existing Stocks ............................................... 130

VI. APPENDICES ..................................................... 133

APPENDIX A. Table of Use Patterns Subject to Reregistration ........ 135
APPENDIX B. Table of the Generic Data Requirements and Studies 

Used to Make the Reregistration Decision ............. 136

APPENDIX C. Citations Considered to be Part of the Data Base Supporting 

the Reregistration of Paraquat Dichloride ............. 155

APPENDIX D. Combined Generic and Product Specific Data Call-In ... 202

Attachment 1. Chemical Status Sheets ...................... 224

Attachment 2. Combined Generic and Product Specific Data 

Call-In Response Forms (Form A inserts) 

Plus Instructions ............................ 226

Attachment 3. Generic and Product Specific Requirement Status 

and Registrant's Response Forms (Form B inserts) 

and Instructions ............................ 229

Attachment 4. EPA Batching of End-Use Products for Meeting 

Data Requirements for Reregistration .......... 237

Attachment 5. List of All Registrants Sent This Data Call-In 

(insert) Notice .............................. 243

Attachment 6. Cost Share, Data Compensation Forms, 

Confidential Statement of Formula Form 

and Instructions ............................ 245

APPENDIX E. List of Available Related Documents ................. 253
i

PARAQUAT DICHLORIDE REREGISTRATION ELIGIBILITY DECISION TEAM

Office of Pesticide Programs:

Biological and Economic Analysis Assessment

George Keitt Biological Analysis Branch

Gabe Patrick Biological Analysis Branch

John Faulkner Economic Analysis Branch

Environmental Fate and Effects Risk Assessment

Sharlene Matten Science Analysis and Coordination Staff

Laura Parsons Environmental Fate and Groundwater Branch

Harry Winnik Ecological Effects Branch

Health Effects Risk Assessment

Mary Clock Risk Characterization and Analysis Branch

Krystyna Locke Toxicology Branch I

Pam Hurley Toxicology Branch I

David Miller Reregistration Support Chemistry Branch

Brian Steinwand Science Analysis Branch

Tina Manville Occupational and Residential Exposure Branch

Registration Support Risk Assessment

Vickie Walters Fungicide-Herbicide Branch

Risk Management

Venus Eagle Reregistration Branch

Judy Coombs Reregistration Branch
ii
GLOSSARY OF TERMS AND ABBREVIATIONS

iii

ADI Acceptable Daily Intake. A now defunct term for reference dose (RfD).

AE Acid Equivalent

a.i. Active Ingredient

ARC Anticipated Residue Contribution 

CAS Chemical Abstracts Service

CI Cation

CNS Central Nervous System

CSF Confidential Statement of Formula

DFR Dislodgeable Foliar Residue

DRES Dietary Risk Evaluation System

DWEL Drinking Water Equivalent Level (DWEL) The DWEL represents a medium specific (i.e. drinking

water) lifetime exposure at which adverse, non carcinogenic health effects are not anticipated to

occur.

EEC Estimated Environmental Concentration. The estimated pesticide concentration in an environment,

such as a terrestrial ecosystem.

EP End-Use Product

EPA U.S. Environmental Protection Agency

FAO/WHO Food and Agriculture Organization/World Health Organization

FDA Food and Drug Administration

FIFRA Federal Insecticide, Fungicide, and Rodenticide Act

FFDCA Federal Food, Drug, and Cosmetic Act

FOB Functional Observation Battery

FQPA Food Quality Protection Act

GLC Gas Liquid Chromatography

GM Geometric Mean

GRAS Generally Recognized as Safe as Designated by FDA

HA Health Advisory (HA). The HA values are used as informal guidance to municipalities and other

organizations when emergency spills or contamination situations occur.

HDT Highest Dose Tested

LC50 Median Lethal Concentration. A statistically derived concentration of a substance that can b e

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 i s

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

LD Lethal Dose-low. Lowest Dose at which lethality occurs. lo

LEL Lowest Effect Level

LOC Level of Concern

LOD Limit of Detection 

LOEL Lowest Observed Effect Level

MATC Maximum Acceptable Toxicant Concentration

MCLG Maximum Contaminant Level Goal (MCLG) The MCLG is used by the Agency to regulat e

contaminants in drinking water under the Safe Drinking Water Act.

μg/g Micrograms Per Gram

mg/L Milligrams Per Liter

MOE Margin of Exposure 

MP Manufacturing-Use Product

MPI Maximum Permissible Intake

MRID Master Record Identification (number). EPA's system of recording and tracking studies submitted.

N/A Not Applicable

NOEC No effect concentration

NPDES National Pollutant Discharge Elimination System

NOEL No Observed Effect Level

NOAEL No Observed Adverse Effect Level

OP Organophosphate

OPP Office of Pesticide Programs
GLOSSARY OF TERMS AND ABBREVIATIONS

iv

PADI Provisional Acceptable Daily Intake

PAG Pesticide Assessment Guideline

PAM Pesticide Analytical Method

PHED Pesticide Handler's Exposure Data 

PHI Preharvest Interval

ppb Parts Per Billion

PPE Personal Protective Equipment

ppm Parts Per Million

PRN Pesticide Registration Notice

Q The Carcinogenic Potential of a Compound, Quantified by the EPA's Cancer Risk Model *

1

RBC Red Blood Cell

RED Reregistration Eligibility Decision

REI Restricted Entry Interval

RfD Reference Dose

RS Registration Standard

RUP Restricted Use Pesticide

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

TC Toxic Concentration. The concentration at which a substance produces a toxic effect. 

TD Toxic Dose. The dose at which a substance produces a toxic effect.

TEP Typical End-Use Product

TGAI Technical Grade Active Ingredient

TLC Thin Layer Chromatography

TMRC Theoretical Maximum Residue Contribution

torr A unit of pressure needed to support a column of mercury 1 mm high under standard conditions.

ug/L Micrograms per liter

WP Wettable Powder

WPS Worker Protection Standard
v

ABSTRACT

The U.S. Environmental Protection Agency has completed its reregistration eligibility

decision of the pesticide paraquat dichloride. This decision includes a comprehensive

reassessment of the required target data supporting the use patterns of currently registered

products. This decision considered the requirements of the recently enacted "Food Quality

Protection Act of 1996" which amended the Federal Food Drug and Cosmetic Act and the

Federal Insecticide, Fungicide and Rodenticide Act, the two Federal statutes that provide the

framework for pesticide regulation in the United States. FQPA became effective immediately

upon signature and all reregistration eligibility decisions (REDs) signed subsequent to August

3, 1996 are accordingly being evaluated under the new standards imposed by FQPA.

In establishing or reassessing tolerances, FQPA requires the Agency to consider

available information concerning aggregate exposures to pesticide residues, including all

anticipated dietary exposures and other exposures for which there is reliable information, as

well as the potential for cumulative effects from a pesticide and other compounds with a

common mechanism of toxicity. The Act further directs EPA to consider the potential for

increased susceptibly of infants and children to the toxic effects of pesticide residue.

Paraquat dichloride is currently registered for the control of weeds and grasses in

agricultural and non-agricultural areas. It is used as a preplant or preemergence herbicide on

vegetables, grains, cotton, grasses, sugarcane, peanuts, potatoes, and on areas for tree

plantation establishment. Paraquat is applied as a directed spray postemergence herbicide

around fruit crops, vegetables, trees, vines, grains, soybeans, and sugarcane. It is used for

dormant season applications on clover and other legumes, and for chemical fallow. It is also

used as a desiccant or harvest aid on cotton, dry beans, soybeans, potatoes, sunflowers,

sugarcane and as a post harvest desiccant on tomatoes. Finally, it is applied to pine trees to

induce resin soaking. Paraquat dichloride is also used on non-crop areas such as public

airports, electric transformer stations and around commercial buildings to control weeds.

The Agency has reassessed paraquat dichloride food and feed tolerances under the

standards of FQPA and determined that the existing tolerances with amendments and changes

as specified in this document meet the safety standards of FQPA. Based on available

information, there is a reasonable certainty that no harm will result to infants and children or

to the general population from aggregate exposure to paraquat dichloride residues. The

Agency only evaluated dietary exposure in the aggregate assessment since there are no

residential or other non-occupational uses of paraquat. Further, based on paraquat’s normal

use patterns and unique environmental fate characteristics, exposures to paraquat in drinking

water are not expected and not a concern. Based on the available data, the Agency does not

believe that the effects produced by paraquat would be cumulative with those of other

structurally related compounds, and therefore has considered only paraquat exposures in the

aggregate assessment. 

In reaching the determination of safety for infants and children, the Agency found that

the toxicity database for paraquat is complete, based on current requirements, and that the

effects observed in pre- and post-natal studies did not indicate any increased sensitivity of

infants and children to paraquat. Therefore, no additional uncertainty factor was used in the

risk assessment.
vi

Under FIFRA, the Agency has concluded that all uses, as prescribed in this document,

will not cause unreasonable risks to humans or the environment. Accordingly, the Agency has

determined that all paraquat dichloride products are eligible for reregistration. 

To mitigate risks of potential dermal exposure to handlers/workers the Agency is

requiring, among other changes, modifications of the personal protective equipment and

reentry intervals of 12 hours for preemergence and directed-spraying uses and 24 hours for

desiccation and harvesting uses. Although a few use scenarios indicated LOC exceedances

on an acute basis for birds, herbivorous and insectivorous mammals, the Agency has

concluded (based on paraquat’s unique environmental fate characteristics) that paraquat

dichloride will not typically pose a threat to birds or mammals once it dries. Also, in

agreement with the registrant, the maximum label rate for paraquat dichloride of 1 lb

cation/Acre is being established to reduce environmental risks to non-target terrestrial and

semi-aquatic plants from drift. Additional data for product chemistry, certain cropfield trials

and spray drift studies are being required to confirm the Agency's risk assessment and

conclusions. 

Accordingly, before reregistering the products containing paraquat dichloride, the

Agency is requiring that product specific data, revised Confidential Statements of Formula

(CSF) and revised labeling be submitted within eight months of the issuance of this

document. These data include product chemistry and acute toxicity testing for each

registration. After reviewing these data and any revised labels and finding them acceptable in

accordance with Section 3(c)(5) of FIFRA, the Agency will reregister a product. Those

products which contain other active ingredients will be eligible for reregistration only when

the other active ingredients are determined to be eligible for reregistration.
1

I. INTRODUCTION

In 1988, the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) was

amended to accelerate the reregistration of products with active ingredients registered prior to

November 1, 1984. The amended Act provides a schedule for the reregistration process to be

completed in nine years. There are five phases to the reregistration process. The first four

phases of the process focus on identification of data requirements to support the reregistration

of an active ingredient and the generation and submission of data to fulfill the requirements.

The fifth phase is a review by the U.S. Environmental Protection Agency (referred to as "the

Agency") of all data submitted to support reregistration.

FIFRA Section 4(g)(2)(A) states that in Phase 5 "the Administrator shall determine

whether pesticides containing such active ingredient are eligible for reregistration" before

calling in data on products and either reregistering products or taking "other appropriate

regulatory action." Thus, reregistration involves a thorough review of the scientific data base

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

potential hazards 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 the

pesticide meets the "no unreasonable adverse effects" criterion of FIFRA.

On August 3, 1996, the Food Quality Protection Act of 1996 (FQPA) (Public Law

104-170) was signed into law. FQPA amends both the Federal Food, Drug, and Cosmetic Act

(FFDCA), 21 U.S.C. 301 et seq., and the Federal Insecticide, Fungicide, and Rodenticide Act

(FIFRA), 7 U.S.C. 136 et seq. The FQPA amendments went into effect immediately. Among

other things, FQPA amended the FFDCA by establishing a new safety standard for the

establishment of tolerances. The FQPA did not, however, amend any of the existing

reregistration deadlines set forth in section 4 of FIFRA. Thus, the Agency is embarking on an

intensive process, including consultation with registrants, States, and other interested

stakeholders, to make decisions on the new policies and procedures that will be appropriate as

a result of enactment of FQPA. This process will include a more in depth analysis of the new

safety standard and how it should be applied to both food and non-food pesticide applications. 

However, in light of the unaffected statutory deadlines with respect to reregistration, the

Agency will continue its ongoing reregistration program while it continues to determine how

best to implement FQPA.

This document presents the Agency's decision regarding the reregistration eligibility of

the registered uses of paraquat dichloride (commonly referred to as “paraquat” in this

document) including the risk to infants and children for any potential dietary, drinking water,

accidental dermal or oral exposures, and cumulative effects as stipulated under the FQPA. 

The document consists of six sections. Section I is the introduction. Section II describes

paraquat dichloride, its uses, data requirements and regulatory history. Section III discusses

the human health and environmental assessment based on the data available to the Agency.

Section IV presents the reregistration decision for paraquat dichloride. Section V discusses

the reregistration requirements for paraquat dichloride. Finally, Section VI is the Appendices

which support this Reregistration Eligibility Decision. Additional details concerning the

Agency's review of applicable data are available on request.
2

II. CASE OVERVIEW

A. Chemical Overview

The following active ingredient(s) are covered by this Reregistration Eligibility

Decision:

Common Name: Paraquat dichloride

Chemical Name: 1,1'-dimethyl-4,4'-bipyridinium dichloride

Chemical Family: Bipyridylnium, dipyridylnium

CAS Registry Number: 1910-42-5

OPP Chemical Code: 061601

Empirical Formula: C12H14Cl2N2

Trade and Other Names: Cekuquat, Cyclone, Dextrone, Esgram, 

Gramoxone, Goldquat, Herboxone,

Prelude, Pillarxone, Pillarquat, Surefire,

Starfire, Total, Toxer 

Basic Manufacturer: Zeneca

B. Use Profile

The following is information on the currently registered uses with an overview

of use sites and application methods. A detailed table of these use of paraquat is in

Appendix A.

For Paraquat dichloride:

Type of Pesticide: Herbicide, Desiccant, Defoliant

Mode of Action: Contact herbicide, without residual soil activity. 

Destroys cell membranes and inhibits

photosynthesis. Only contacted leaves are killed,

so regrowth can occur from undamaged parts of

perennials.
3

Use Groups and Sites:

TERRESTRIAL FOOD CROP

acerola (West Indies cherry); apricot; asparagus; avocado; banana;

blackberry; blueberry; boysenberry; broccoli; cabbage; cabbage,

Chinese; carrot (including tops); cauliflower; cherry; cocoa; coffee;

collards; cucumber; eggplant; fig; filbert (hazelnut); garlic;

groundcherry (strawberry tomato/tomatillo); guava; hops; kiwifruit;

lettuce; loquat; macadamia nut (bushnut); manioc (cassava); melons;

melons, cantaloupe; melons,musk; melons, water; mint; nectarine; olive;

onion; papaya; passion fruit; peach; pear; pecan; pepino (melonpear);

pepper; pepper (chili type); pineapple; pistachio; plum; potato,

white/Irish; prune; pumpkin; raspberry (black, red); rhubarb; smallfruits;

squash (all or unspecified); strawberry; sugarbeet; taro; walnut

(English/black); yam; yautia 

TERRESTRIAL FOOD+FEED CROP 

almond; apple; barley; beans, asparagus; beans, dried-type; beans,

mung; beans, succulent (lima); beans, succulent (snap); citrus fruits;

corn (unspecified); corn, field; corn, pop; corn, sweet; cotton

(unspecified); garbanzos (including chickpeas); grapes; guar; hops;

legume vegetables; mint; oats; orchards (unspecified); peanuts; peanuts

(unspecified); peas (unspecified); peas, field; peas, pigeon; peppermint;

potato, white/Irish; safflower; safflower (unspecified); small fruits;

small grains (unspecified); sorghum; sorghum (unspecified); soybeans

(unspecified); soybeans, edible; spearmint; sugarbeet; sugar crops;

sugarcane; sunflower; tomato; turnip; vegetables (unspecified); wheat

TERRESTRIAL FEED CROP 

alfalfa; barley; beans; clover; crownvetch; legume vegetables;

lespedeza; lupine; pastures; sainfoin; timothy; trefoil; tyfon; vetch;

wheat

TERRESTRIAL NON-FOOD CROP

agricultural fallow/idleland; airports/landing fields;

commercial/industrial lawns; commercial/institutional/industrial;

premises/equipment (outdoor); fencerows/hedgerows; grasses grown for

seed; industrial areas (outdoor); jojoba; nonagricultural outdoor

buildings/structures; nonagricultural uncultivated areas/soils;

ornamental and/or shade trees; peach (non-bearing, seed beds);

recreation area lawns; tomato (post-harvest); wood protection treatment

to forest products (seasoned)

FORESTRY 

forest plantings (reforestation programs); pine (forest/shelterbelt);

shelterbelt plantings
4

TERRESTRIAL NON-FOOD

ornamental and/or shade trees; ornamental herbaceous plants;

ornamental woody shrubs and vines; non-crop areas such as public

airports, electric transformer stations and around commericial buildings

Target Pests: Annual broadleaf and grassy weeds (top kill of

perennials). 

Formulation Types Registered:

MANUFACTURING PRODUCT 

Soluble concentrate/liquid 43.5000%

END USE PRODUCT 

Soluble concentrate/liquid 23.2000 to 43.5000%

(23.2000%, 29.1000%, 29.4200%,

30.3000%, 37.000%, 43.5000%)

Multiple active ingredient products contain: 

diuron (035505)

Method and Rates of Application:

TYPES OF TREATMENT

Band treatment; Bark treatment (cut); Basal spray treatment; Bore-hole

treatment; Broadcast; Directed spray; Ground spray; Soil band

treatment; Soil broadcast treatment; Spot soil treatment; Spot treatment;

Spray; Strip treatment. 

EQUIPMENT 

Aircraft; Backpack/Knapsack sprayer; Hand held spray wand; Sprayer;

Ground/Tractor-drawn ground boom.

TIMING 

At cracking; At planting; August; Dormant; Early spring; Established

plantings; Fall; Fallow; Foliar; July; Postemergence; Postharvest;

Postplant; Posttransplant; Preemergence; Preharvest; Preplant; Preplant

(Spring); Ratoon; Seed bed; Seedling stage; Spring; Stubble; When

needed; Winter.

C. Estimated Usage of Pesticide

This section summarizes the best estimates available for the pesticide uses of

paraquat dichloride. These estimates are derived from a variety of published and

proprietary sources available to the Agency. The data, reported on an aggregate and

site (crop) basis, reflect annual fluctuations in use patterns as well as the variability in

using data from various information sources.
5

Estimates of paraquat usage vary widely from different sources. Rather than

providing a range of estimates, the table below gives what the Agency believes to be

the most likely estimate and also a likely maximum estimate. This maximum is not a

strict upper bound limit, but an estimate. There is a very small probability that the

actual amount of paraquat being used would exceed this estimated likely maximum.

Most of paraquat usage is for field crops because of the high acreage of these

crops. The percent crop treated and average application rates for field crops is less

than that for fruits and vegetables. The average percent crop treated on fruits is

significantly higher than for vegetables and field crops. The highest usages in pounds

a.i. are for corn, soybeans, cotton, and apples.
6

PARAQUAT QUANTITATIVE USAGE ANALYSIS

 Acres Acres Treated (000) % of Crop Treated Total AI (000 lbs) Application

VEGETABLE/MELONS Planted ------------------- ----------------- ------------------ ------------

----------------- ------- Likely Likely Likely Likely Likely Likely lbs ai/year/

 (000) Estimate Max Estimate Max Estimate Max treated acres

Eggplant 4 1 2 25.0% 50.0% 2 2 2.0

Peppers 101 18 33 17.8% 32.7% 18 34 1.0

Lettuce 283 8 11 2.8% 3.9% 6 8 0.8

Sweet Corn 748 6 25 0.8% 3.3% 5 21 0.8

Potatoes 1,403 40 73 2.9% 5.2% 25 39 0.6

Tomatoes 480 73 93 15.2% 19.4% 75 111 1.0

Mint 147 39 . 26.5% . 20 . 0.5

Cole Crops 263 2 4 0.8% 1.6% 1 2 0.5

 Broccoli 107 . 1 . 1.0% . 1 1.0

 Cabbage 84 . 3 . 3.0% . 1 0.2

 Cauliflower 57 . 1 . 1.0% . 1 1.0

 Collards 15 . 0 . 1.0% . 0 2.0

Cucurbits, not melons 250 15 24 6.0% 9.6% 12 19 0.8

 Cucumbers 151 12 . 7.9% . 10 . 0.8

 Pumpkins 41 1 . 2.4% . 1 . 1.0

 Squash 58 2 . 3.4% . 1 . 0.5

Melons 349 10 16 2.9% 4.6% 8 11 0.8

 Cantaloupe 110 . 6 0.0% 5.5% . 2 0.3

 Watermelons 239 . 10 0.0% 4.2% . 8 0.8

Vegetables, Other 330 20 30 6.1% 9.1% 13 23 0.8

 Asparagus 55 9 12 16.4% 21.8% 6 8 0.7

 Carrots 104 1 . 1.0% . 1 . 0.5

 Garlic 22 4 . 18.2% . 3 . 0.8

 Onions 149 6 . 4.0% . 3 . 0.5

Subtotal 4,358 232 293 185 255

Average 5.3% 6.7% 0.8
7

PARAQUAT QUANTITATIVE USAGE ANALYSIS (continued)

 Acres Acres Treated (000) % of Crop Treated Total AI (000 lbs) Application

FRUITS/CITRUS/NUTS Planted ------------------- ----------------- ------------------ ------------

------------------ ------- Likely Likely Likely Likely Likely Likely lbs ai/year/

 (000) Estimate Max Estimate Max Estimate Max treated acres

Citrus 1,229 108 295 8.8% 24.0% 94 192 0.9

 Grapefruit 201 15 35 7.5% 17.4% 14 24 0.9

 Lemons 66 1 6 1.5% 9.1% 1 5 1.0

 Oranges 911 80 240 8.8% 26.3% 70 150 0.9

 Citrus, Other 51 12 14 23.5% 27.5% 9 13 0.8

Pome Fruits 768 251 315 32.7% 41.0% 248 305 1.0

 Apples 656 230 280 35.1% 42.7% 220 264 1.0

 Pears 84 19 26 22.6% 31.0% 25 35 1.3

 Pome-Like, Other * 28 2 9 7.1% 32.1% 3 6 1.5

Stone Fruits 713 197 269 27.6% 37.7% 147 206 0.7

 Cherries 132 48 54 36.4% 40.9% 46 56 1.0

 Peaches 248 92 120 37.1% 48.4% 61 86 0.7

 Plums & Prunes 138 27 42 19.6% 30.4% 20 30 0.7

 Stone-Like, Other * 195 30 53 15.4% 27.2% 20 34 0.7

Grapes 874 162 200 18.6% 22.9% 101 125 0.6

Blueberries 59 9 . 15.3% . 5 . 0.6

Raspberries 11 2 . 18.2% . 1 . 0.5

Strawberries 30 6 9 20.0% 30.0% 6 9 1.0

Nut Trees 1,277 180 282 14.1% 22.1% 164 227 0.9

 Almonds 455 75 130 16.5% 28.6% 80 96 1.1

 Pecans 496 64 97 12.9% 19.6% 50 78 0.8

 Walnuts 217 26 30 12.0% 13.8% 20 29 0.8

 Nut Trees, Other 109 15 25 13.8% 22.9% 14 24 0.9

Subtotal 4,961 915 1,370 766 1,064

Average 18.5% 27.6% 0.8

* Fruit trees, other

 Pome-like, other includes kiwifruit, figs, and papayas.

 Stone-like, other includes apricots, nectarines, avocados, and olives.
8

PARAQUAT QUANTITATIVE USAGE ANALYSIS (continued)

 Acres Acres Treated (000) % of Crop Treated Total AI (000 lbs) Application

FIELD/CERERAL CROPS Planted ------------------- ----------------- ------------------ ------------

------------------- ------- Likely Likely Likely Likely Likely Likely lbs ai/year/

 (000) Estimate Max Estimate Max Estimate Max treated acres

Alfalfa 24,835 130 180 0.5% 0.7% 60 100 0.5

Hay, other 32,605 20 32 0.1% 0.1% 9 14 0.5

Pasture/Rangeland . . . . 0.1% . . .

Corn 78,234 1,400 2,210 1.8% 2.8% 800 1,200 0.6

Cotton 13,944 900 2,330 6.5% 16.7% 280 740 0.3

Sorghum 10,307 150 450 1.5% 4.4% 56 120 0.4

Soybeans 61,564 1,020 1,940 1.7% 3.2% 540 960 0.5

Barley 6,838 28 55 0.4% 0.8% 11 22 0.4

Oats/Rye 5,085 4 7 0.1% 0.1% 2 3 0.5

Wheat 70,014 203 335 0.3% 0.5% 81 124 0.4

 Wheat, Spring 20,861 3 7 0.0% 0.0% 1 2 0.3

 Wheat, Winter 49,153 200 328 0.4% 0.7% 80 122 0.4

Hops 42 35 . 83.3% . 23 . 0.7

Beans/Peas, Dry 2,223 20 70 0.9% 3.1% 7 18 0.4

Beans/Peas, Vegetable 719 10 21 1.4% 2.9% 5 9 0.5

Peanuts 1,691 464 930 27.4% 55.0% 72 140 0.2

Sunflower 2,044 15 . 0.7% . 11 . 0.7

Safflower 323 31 . 9.6% . 28 . 0.9

Sugar Beets 1,465 3 9 0.2% 0.6% 2 4 0.7

Sugarcane 879 40 110 4.6% 12.5% 18 55 0.5

Subtotal 312,812 4,473 8,679 2,005 3,509

Average 1.4% 2.8% 0.4

ALL CROPS

 Total 322,131 5,620 10,342 2,955 4,828

 Average 1.7% 3.2% 0.5

NOTES:

Numbers may not agree due to rounding.

Likely estimates and maximums are not ranges and both may not be provided when data is insufficient.

Application (last column) is the likely estimate of total lb ai divided by acres treated.

SOURCES: EPA data, USDA, National Center for Food and Agricultural Policy
9

D. Data Requirements

Data required in the June 1987 Registration Standard for paraquat dichloride

include studies on product chemistry, ecological effects, toxicology, environmental

fate, and residue chemistry. A Data Call-In issued December 1991 required further

testing for ecological effects, environmental fate and residue chemistry. These data

were required to support the uses listed in the Registration Standard. Appendix B

includes all data requirements identified by the Agency for currently registered uses

needed to support reregistration.

E. Regulatory History

Paraquat was discovered in 1882 and has been used as an oxidation-reduction

indicator under the name of methyl virologen since 1932. The first commercial

paraquat formulation for agricultural use was produced by Imperial Chemical

Industries, Ltd. in England and was registered there in 1962. 

Paraquat dichloride was registered in the United States in 1964 for use as a

contact herbicide to control or suppress a broad spectrum of emerged weeds. The

Agency classified paraquat dichloride as a Restricted Use pesticide due to high acute

toxicity to animals and people from intentional or inadvertent exposure. This action

was taken by the Agency through regulations proposed in the September 1, 1977 (42

FR 44170) and finalized in the February 9, 1978 (43 FR 5782) issues of the

FEDERAL REGISTER. Under the Restricted Use classification, only certified

applicators are authorized to apply paraquat dichloride end-use products.

In 1978 paraquat dichloride was accepted as a candidate for the Special Review

process based on the following areas where paraquat dichloride was believed to

exceed the risk criteria under 40 CFR 162.11: teratogenicity, lack of emergency

treatment, chronic effects, reproductive effects, oncogenicity (data gap), mutagenicity

(data gap), and acute effects. Other areas of concern included mammalian toxicity and

avian reproductive effects. Upon conclusion of the Special Review evaluation in

October 1982 (43 FR 30613), the Agency issued a Final Position Document which

concluded that the available data did not support paraquat dichloride being placed into

the Special Review status since the risk criteria identified in 1978 had not been

exceeded.

 

After the Special Review evaluation, the Agency believed that the acute effects

level was very close to estimated applicator exposures. Therefore, a Data Call-In was

issued for paraquat dichloride requiring additional dermal and inhalation data and

more precise information to assess the potential of acute effects as a result of

applicator exposure to this compound. A Registration Standard for paraquat

dichloride was issued in June 1987 (NTIS #PB88-217005) in which the Agency
2 ClN

+

N

+ CH3

H3C

10

evaluated the studies submitted as a result of the previous DCI. This Reregistration

Eligibility Decision reflects a reassessment of all data which were submitted in

response to the Registration Standard and subsequent December 1991 DCI.

III. SCIENCE ASSESSMENT

A. Physical Chemistry Assessment

Paraquat dichloride (1,1'-dimethyl-4,4'-bipyridinium dichloride) is a

nonselective contact herbicide, desiccant, defoliant, and plant growth regulator

primarily used on field crops and fruit and nut crops.

Empirical Formula: C12H14Cl2N2

Molecular Weight: 257.2

CAS Registry No.: 1910-42-5

OPP Chemical Code: 061601

Production of the paraquat dimethyl sulfate salt [1,1'-dimethyl-4,4'-

bipyridinium bis(methyl sulfate); OPP Chemical Code 061602] has been discontinued;

there are no active uses or products.

IDENTIFICATION OF ACTIVE INGREDIENT

Paraquat dichloride is an off-white, odorless hygroscopic (holding moisture)

powder with a melting point of approximately 340 C. Paraquat dichloride is freely

soluble in water, slightly soluble in alcohols, and insoluble in nonpolar organic

solvents. The Technical Grade Active Ingredient (TGAI) is corrosive to metals,

hydrolyzes under alkaline conditions, and decomposes photochemically.

MANUFACTURING-USE PRODUCTS

There are two paraquat dichloride manufacturing-use products (MPs) registered

to Zeneca AG Products under OPP Chemical Code 061601; they are the 43.5%

formulation intermediates (FIs) (EPA Reg. Nos. 10182-115 and 10182-362). 
11

B. Human Health Assessment

1. Toxicology Assessment

The toxicological data base for paraquat dichloride is adequate and will

support reregistration eligibility.

a. Acute Toxicity

The table below defines the different Acute Toxicity Categories

for the different routes of administration.

Hazard

Indicators

Acute Toxicity Categories

Category I = Category II = Category III = Category IV

very highly or moderately slightly toxic = practically

highly toxic toxic non-toxic

Oral LD50 Up to and including From 50 thru 500 From 500 thru 5000 Greater than 5000

50 mg/kg mg/kg mg/kg mg/kg

Inhalation LC50 Up to and including From 0.05 thru 0.5 From 0.5 thru 5.0 Greater than 5.0

0.05 mg/L mg/L mg/L mg/L

Dermal LD50 Up to and including From 200 thru From 2000 thru Greater than 5000

200 mg/kg 2000 mg/kg 5000 mg/kg mg/kg

Eye Effects Corrosive; corneal Corneal opacity Corneal opacity; Corneal opacity

opacity not reversible within 8- irritation reversible cleared within 24

reversible within 21 days within 7 days hours

21 days

Skin Effects Corrosive Severe irritation at Moderate irritation Mild or slight

72 hours at 72 hours irritation at 72

hours

The table below summarizes the acute toxicity studies on

paraquat dichloride and the Toxicity Categories for the different routes

of administration.
12

ACUTE TOXICITY DATA FOR PARAQUAT DICHLORIDE

TEST RESULTS CATEGORY MRID No.

Acute oral LD50 344 mg/kg II 43685001

 (rat) 283 mg/kg #

Acute Dermal LD50 >2000 mg/kg# III 43685002

 (Rat)

Acute Inhalation 1 μg/L + ## I 00046105

 LC (Rat) 50

Eye Irritation Moderate to severe II 43685003

 (Rabbit) irritation #

Dermal Irritation Minimal irritation; IV 43685004

 (Rabbit) PIS = 0.5 #

Dermal Sensitization Negative # -- 43685005

 (Guinea pig)

 # The test material used in these studies was paraquat technical concentrate which is 45.6% paraquat dichloride (cation

content: 33% w/w). The LD values are expressed in terms of paraquat dichloride (and not as paraquat cation). 50

 ## The test material used in this study was crystalline paraquat dichloride. Purity was not specified, but crystalline

paraquat dichloride used in other studies was 99.9% pure. The LC50 value is expressed as paraquat dichloride (and

not as paraquat cation).

The following toxic signs were observed in the above studies:

Acute Oral LD (Rat): Decreased activity, dehydration, hypothermia, 50

irregular breathing, chromodacryorrhea, piloerection, sides pinched in,

stains around nose and mouth, upward curvature of the spine, reduced

splay reflex and mottling and dark areas in the lungs. Doses tested: 

100, 250, 400 or 600 mg/kg, in SPF Wistar-derived male and female

rats. (MRID 43685001)

Acute Dermal LD50 (Rat): Slight or moderate skin irritation (edema

and/or erythema), and scabbing and thickening of the skin at the

application site. There was no mortality. Dose tested: 2000 mg/kg

(limit dose), in SPF Wistar-derived male and female rats (intact skin,

24-hour contact period). (MRID 43685001)

Acute Inhalation LC50 (Rat): Pale and swollen kidneys, and lung

changes (congestion, occasional petechial hemorrhages, and increased

number of polymorphs and histiocytes around the bronchi and vessels) -

all at the two highest concentrations tested. Concentrations tested

(analytical values): 0.4, 0.75, 1.3, 1.5, 2.6, 4.8, 13.7 and 32.5 ug/L,

expressed as paraquat dichloride, in Alderley Park SPF rats. 6-Hour

exposure to respirable particles [2.5 u or smaller]. (MRID 00046105)
13

Primary Eye Irritation (Rabbit): Corneal effects (slight or mild opacity

involving 1/4-1/2 of the cornea), cleared by day 17; and conjunctival

effects (slight to severe redness and discharge, and slight to mild

chemosis). Regression times (days after dosing): chemosis, 14;

redness, 28 (end of study); and discharge, > 28 (still present in 2/3 of

the surviving rabbits at the termination of the study. Dose tested: 0.1

mL of the undiluted test material, in 3 young adult female New Zealand

White rabbits (unwashed eyes, Draize scoring). Moderate to severe

ocular irritant = class 5 on a scale of 1-8. (MRID 43685003)

Primary Dermal Irritation (Rabbit): Very slight erythema in all 3 rabbits

(score 0.7-1.0 on a scale of 0-4); very slight edema in 1 rabbit (score 1.0

on a scale 0-4); and desquamation, thickening, and scabbing in 1 rabbit. 

Regression times: erythema, in 2-3 days after dosing (2 rabbits) and in

27 days (1 rabbit); edema, in 7 days; and other signs, in 34 days (end of

study). Primary dermal irritation score 0.5 at 72 hours. Dose tested: 

0.5 mL of undiluted test material, in 3 young adult female New Zealand

White rabbits (4-hour exposure, intact skin, Draize scoring). (MRID

43685004)

Dermal Sensitization (Guinea Pig): Not a skin sensitizer under the

conditions of the maximization test of B. Magnusson and A.M. Kligman

(Allergic Contact Dermatitis in the Guinea Pig; 1970). Positive control

used: 2-mercaptobenzothiozole. (MRID 43685005)

b. Subchronic Toxicity

90-Day Feeding, Non-Rodent:

In a repeated dose oral toxicity study, male and female beagle

dogs, 3/sex/group, received paraquat dichloride for 13 weeks at the

following levels, expressed as paraquat cation: 0, 7, 20, 60 or 120 ppm

(0, 0.18, 0.5, 1.5 or 3.0 mg/kg/day, respectively). The test material,

added to the diet, was the technical grade aqueous solution containing

32.2% w/w of paraquat cation. The dogs, aged 7-8 months at the start

of the study, were given 400 g of the appropriate diet mix every

morning. Any remaining food was removed and weighed the following

morning. At the 7 ppm (0.18 mg/kg) and the 20 ppm (0.5 mg/kg)

levels, paraquat had no effect on any of the parameters examined. 

Toxic signs observed in the 60 ppm (1.5 mg/kg) group included

increased absolute (39-41%) and relative (44-56%) lung weight,

alveolitis and alveolar collapse. Unless stated otherwise, the following

treatment-related symptoms were observed in both sexes at the 120 ppm

(3.0 mg/kg) level: weight loss (4-8%), decreased food intake (22-67%)
14

for one surviving female during the last 6 weeks of the test, increased

absolute (75-76%) and relative (92-104%) lung weight, marked

dyspnea, harsh rales, slow and/or irregular heart beat, large lesions in

the lungs (alveolitis), alveolar collapse and high mortality (2/3 males

and 2/3 females during study days 16-23). Based on the above

findings, the NOEL and LOEL for systemic toxicity, for both sexes, are

20 ppm (0.5 mg/kg/day) and 60 ppm (1.5 mg/kg/day), respectively. 

Although there was a 12% weight loss (P<0.01) in the female 20 ppm

group during week 13, this loss was greater than that observed in the 60

ppm and 120 ppm groups, and, therefore, did not appear to be

treatment-related. (MRID 00072416) 

21-Day Dermal Toxicity, Rabbit:

In a repeated dose dermal toxicity study, male and female New

Zealand white rabbits, 6/sex/group, were exposed (intact skin) to

paraquat dichloride (cation content: 43.5%) for 21 consecutive days (6

hours/day). Paraquat dichloride was applied as an aqueous solution (1.0

mL/kg b.w.) at the following concentrations: 0, 1.5, 3.4, 7.8 or 17.9

mg/kg/day (0, 0.5, 1.15, 2.6 or 6.0 paraquat cation, respectively). 

Treatment-related effects were observed only at the two highest

concentrations tested. In the 2.6 mg cation/kg group, scabbing at the

dosing site was seen in two males and one female. The following toxic

signs were observed in the 6.0 mg cation/kg group, in all rabbits, at the

dosing site: scabbing; slight to well-defined erythema; minimal to

moderately severe inflammation, acanthosis and hyperkeratosis (females

only); slight to severe erosion/ulceration and surface exudate; and

decreases in absolute weight (18%) and relative weight (organ/body

weight and organ/brain weight ratios; 17-22%) of testes. No gross

histological changes were found in the lungs, the target organ for

paraquat. Based on dermal irritation, the NOEL and LOEL are,

respectively, 1.15 mg/kg/day and 2.6 mg/kg/day, expressed as paraquat

cation. (MRID 00156313) 

21-Day Inhalation Toxicity, Rat:

In a repeated dose inhalation toxicity study, Sprague-Dawley rats

were exposed (whole body) to respirable aerosols of paraquat dichloride

(cation content: 40%; particle size: < 2 um in diameter) for 3 weeks (6

hours/day, 5 days/week). The concentrations of paraquat cation in the

inhalation chambers were 0, 0.01, 0.1, 0.5 and 1.0 ug/L (nominal) or 0,

0.012, 0.112, 0.487 and 1.280 ug/L, respectively, (analytical). The

numbers of rats of each sex assigned to these groups were as follows: 
15

32 (control group), 16 (0.5 ug/L group) and 36 (remaining groups). 

Parameters examined included observations for toxic signs, body

weights and food consumption. One-half of the rats in each group were

examined grossly and microscopically after 15 exposures and the

remaining rats were examined 2 weeks after the termination of the

exposures (recovery period). These examinations were restricted only

to the respiratory tract (nasal passages, pharynx, tongue, larynx, trachea

and lungs). The 1.0 ug/L group was abandoned after the first exposure

because 28 males (78%) and 29 females (80%) died from respiratory

failure after that exposure. 

Toxic signs were not observed in the 0.01 ug/L group and there

was no mortality in this or the other test groups. All rats in the 0.1 ug/L

group had nasal discharge and squamous keratinizing metaplasia, and/or

hyperplasia of the epithelium of the larynx. The changes in the

ephithelium were still observed in 69% of the rats sacrificed at the end

of the recovery period. The following findings were reported for the 0.5

ug/L group examined after 3 weeks of treatment: (1) extensive

ulceration, necrosis, inflammation and squamous keratinizing

metaplasia, and marked/moderate hyperplasia of adjacent epithelia in

the larynx of all rats; and (2) aggregations of foamy macrophages in the

bronchioles or alveoli, hypertrophy of the epithelium and thickened

alveolar walls in the lungs of most or all rats. After a 2-week recovery

period, no ulceration or necrosis was observed in the larynx, but

changes in the lungs were still seen. In addition, disruption of

bronchiolar epithelium, adjacent to the macrophage aggregation, was

noted.

Considering the above findings, the NOEL and LOEL for subchronic (3 weeks) inhalation toxicity, for both sexes, are 0.01 ug/L and

0.10 ug/L, respectively, expressed as paraquat cation. (MRID

00113718)

c. Chronic Toxicity

Chronic Toxicity/Oncogenicity, Rodent:

In this chronic feeding/carcinogenicity study, Fischer 344 rats,

80/sex/group, were fed diets containing paraquat dichloride (cation

content: 32.69%) for 113-117 weeks (males) and 122-124 weeks

(females). Based on the results of a preliminary study, the doses of

paraquat selected for this study were 0 (Group 1), 0 (Group 2), 25

(Group 3), 75 (Group 4) or 150 ppm (Group 5), expressed as paraquat

cation (nominal concentrations). Assuming that, for an older rat, 1 ppm
16

= 0.05 mg/kg/day, these doses corresponded to 0, 0, 1.25, 3.75 or 7.5

mg of paraquat cation/kg/day, respectively. Twenty rats from each

group (10 of each sex) were sacrificed after one year of treatment: 5 of

each sex/group, for the usual interim sacrifice and another 5 of each

sex/group, to determine paraquat concentration in tissues. According to

the initial protocol, this study was to be terminated after 104 weeks. 

However, because of the low number of deaths during that period, the

study was extended until survival was reduced to 50%in any one of

Groups 1-4 (Group 5 was excluded from consideration).

Starting with the test week 6, the female rats at all dose levels

ingested more paraquat (15-33%) per kilogram of body weight than did

the male rats at the same dose levels. With the exception of minimal

lens opacities in 3/60 (5%) males and 6/60 (10%) females, nothing

remarkable was observed in the 25 ppm group. Since these incidences

were only 1% and 3% higher than in the control males and females,

respectively, and occurred mostly after week 104, they appeared to be

an acceleration of the normal aging process and not a qualitatively

different effect.

The only treatment-related statistically significant effects

observed in the 75 ppm group, were increased incidence of (1)

opacities/cataracts in the males (4%) and the females (19%, P< 0.01);

(2) ptosis/swollen eyelids in the females (7%); and (3) non-neoplastic

lung lesions in the male nonsurvivors (alveolar macrophages; 14%,

P<0.05). In the case of the ocular lesions, there were about as many

opacities as there were cataracts. 

In the 150 ppm group, the incidence of eye opacities/cataracts

was 37% (controls, 4%) in the males and 58% (controls, 4%) in the

females. Only one opacity and all cataracts were observed in each male

and female high-dose groups. Compared with the controls, other

findings observed in the 150 ppm group were (1) slight decreases in the

food consumption for the males (3-7%) and the females (3-8%) during

most of the study; (2) decreased body weight gain during weeks 11-68

for the males (10-34%) and during weeks 27-78 for the females (11-

34%); (3) decreased food utilization for the males (12-21%) and females

(11-13%) during weeks 13-52; (4) increased relative weight of the lungs

(lung/body weight ratio) in the males (16%, P<0.05) and the females

(14%, P<0.05) sacrificed at the termination of the study; (5) increased

incidence of hydrocephalus in the females sacrificed at the termination

of the study (36%, P<0.01); (6) increased incidence of alveolar

macrophages in the male nonsurvivors (25%, P<0.01) and in rats
17

sacrificed at the termination of the study (males, 30% and females,

17%); and (7) increased incidence of alveolar epithelization (12%) and

slight peribronchial lymphoid hyperplasia (26%, P<0.05) in the males at

the termination of the study. 

The above findings show that paraquat enhanced the

development of ocular lesions in all of the treated groups. The

predominant lesions detected ophthalmoscopically were lenticular

opacities and cataracts. These lesions were either not observed or were

observed infrequently before the week 103. At test week 103, doserelated statistically significant (P<0.001) increases in the incidence of

ocular lesions were observed only in the mid-dose and high-dose male

and female groups. Based on these findings, the NOEL (approximate)

and the LOEL for systemic toxicity, for both sexes, are 25 ppm (1.25

mg/kg/day) and 75 ppm (3.75 mg/kg/ day), respectively. (MRID

00138637) 

In another chronic feeding/carcinogenicity study, Wistar strain

rats, 62/sex/group, were fed diets containing technical grade paraquat

dichloride (purity: 98%) for 104 weeks. Based on the results of a

preliminary study, the doses of paraquat selected for this study were 0,

6, 30, 100 or 300 ppm, expressed as paraquat dichloride (nominal

concentrations). These values were equivalent to 0, 0.25, 1.26, 4.15 or

12.25 mg/kg/day, respectively (males) and 0, 0.30, 1.50, 5.12 or 15.29

mg/kg/day, respectively (females), expressed as paraquat dichloride

(analytical concentrations). The interim sacrifices, using 6 rats/sex/

group, took place after 26 and 52 weeks of treatment.

Findings different from those in the controls were observed only

in the 300 ppm group and included (1) increased mortality in males

(66%; controls, 40%) and females (52%; controls, 42%); (2) decreased

erythrocytes, hemoglobin, and serum protein in males and females; (3)

decreased hematocrit, glucose and corpuscular cholinesterase activity in

males (7.9% at week 52); (4) decreased leucocytes, albumin/globulin

ratio and alkaline phosphatase (34%), GOT (glutamic-oxaloacetic

transaminase, 18%) and GPT (glutamic-pyruvic transaminase, 23%)

activities in females; (5) increased polymorphonucleocytes in males; (6)

increased potassium and glucose in females; (7) decreased absolute

and/or relative weights of heart in males (10%) and females (14%); and

liver (14%) and brain (8%) in females; and (8) decreased absolute

weights of kidneys in males (13%) and females (17%), and ovaries (32-

39%). 
18

Ocular changes were not detected before the initiation of

treatment. After the treatment was started, cataracts were observed

during each examination (weeks 26, 52 and 104) in 1 to 4 rats per

group, including controls. At test weeks 52 and 104, corneitis (keratitis)

and conjunctivitis were also observed in all groups, including controls. 

In this study, the incidence of ocular changes was low and doseunrelated. Considering the test weeks 26-104, the incidence of ocular

changes in the male and female treated rats was as follows: cataracts,

1.6-17.6% (controls 1.6-13.8%); corneitis, 0-5.9% (controls, 0-6.7%);

and conjunctivitis, 0-5.4% (controls, 0-6.7%). Ocular changes,

therefore, do not appear to be caused by paraquat in this study.

Based on the above findings, the systemic NOEL is 100 ppm of

paraquat dichloride (4.15 and 5.12 mg/kg/day, for males and females,

respectively); or 3.0 mg/kg/day (males) and 3.7 mg/kg/day (females),

expressed as paraquat cation. The systemic LOEL is 300 ppm of

paraquat dichloride (12.25 and 15.29 mg/kg/day, for males and females,

respectively); or 9.0 mg/kg/day (males) and 11.2 mg/kg/day (females),

expressed as paraquat cation.(MRID 40218001) 

Chronic Toxicity, Non-Rodent:

Groups of 6 male and 6 female Alderley Park beagle dogs were

fed diets containing technical grade paraquat dichloride (cation content:

32.3%) for 52 weeks. The amount of food offered daily each dog was

400 g. The dose levels used were 0, 15, 30 or 50 ppm, expressed as

paraquat cation. Based on the actual group mean body weights and

food consumption, these doses corresponded to 0, 0.45, 0.93 or 1.51 mg

of paraquat cation/kg/day, respectively, in the case of male dogs. For

female dogs, these doses corresponded to 0, 0.48, 1.00 or 1.58 mg or

paraquat cation/kg/day, respectively. The doses used in this study were

based on the results obtained in the 90-day feeding study (MRID

00072416) which has been discussed in the subchronic toxicity section

of this document. 

The major effect of paraquat was a dose-related increase in the

severity and extent of chronic pneumonitis in the mid-dose and highdose male and female dogs. This effect was noted also in the low-dose

male group, but was minimal when compared with the male controls. 

Chronic pneumonitis was less severe in the low-dose female group than

in the female controls. Because 44 dogs (out of 48 studied), including 6

male and 5 female controls, had some degree of chronic pneumonitis,

paraquat had no effect on the incidence of this lesion. Other findings
19

observed only in the high-dose dogs were (1) significant (P<0.01)

increases in the group mean lung weights (absolute or adjusted for body

weight, 36% in males and 61% in females) and in spleen weights

(absolute or adjusted for body weights, 50-55% in males and 38-43% in

females), when the paraquat-treated dogs were compared with the

controls; (2) hyperpnea in 67% males and females; and (3) increased

vesicular sound in 50% males and 67% females. Only one lenticular

cataract (minimal, in a mid-dose female) was observed in this study. 

Based on the above findings, the systemic NOEL is 15 ppm (males:

0.45 mg/kg/day and females: 0.48 mg/kg/day, expressed as paraquat

cation). The systemic LOEL is 30 ppm (males:0.93 mg/kg/day and

females: 1.00 mg/kg/day, expressed as paraquat cation). (MRID

00132474) 

d. Carcinogenicity

The Agency has received and reviewed four carcinogenicity

studies as are detailed below.

Chronic Feeding/Carcinogenicity Study with Fischer 344 Rats

In this chronic feeding/carcinogenicity study, Fischer 344 rats,

80/sex/group, were fed diets containing paraquat dichloride (cation

content: 32.69%) for 113-117 weeks (males) and 122-124 weeks

(females). Based on the results of a preliminary study, the doses of

paraquat selected for this study were 0 (Group 1), 0 (Group 2), 25

(Group 3), 75 (Group 4) or 150 ppm (Group 5), expressed as paraquat

cation (nominal concentrations). Assuming that, for an older rat, 1 ppm

= 0.05 mg/kg/day, these doses corresponded to 0, 0, 1.25, 3.75 or 7.5

mg of paraquat cation/kg/day, respectively. Twenty rats from each

group (10 of each sex) were sacrificed after one year of treatment: 5 of

each sex/group for the usual interim sacrifice, and another 5 of each

sex/group, to determine paraquat concentration in tissues. According to

the initial protocol, this study was to be terminated after 104 weeks. 

However, because of the low number of deaths during that period, the

study was extended until survival was reduced to 50% in any one of

Groups 1-4 (Group 5 was excluded from consideration). Gross

necropsy was performed on all rats on the study. With the exception of

the rats which were used for the determination of paraquat concentration

in tissues, all rats on the study were also examined microscopically.

During the initial review of this study, there were concerns that

paraquat might be carcinogenic in the rat. There was a dose-related
20

increase in the incidence of pulmonary neoplasms (adenomas and

carcinomas), but especially adenomas, in the male and female rats. The

incidence of pulmonary neoplasms was 2.9, 5.7, 8.6 and 10.1% in the

control, low-dose, mid-dose and high-dose male groups, respectively. 

The corresponding values for the female groups were 0, 2.9, 4.3 and

14.3%, respectively. A statistically significant (P<0.001) increase was

observed only in the pulmonary adenomas and only in the high-dose

female rats. Most of the neoplasms were observed at the termination of

the study. However, there were difficulties in characterizing pulmonary

lesions as non-neoplastic or neoplastic, or as adenomas or carcinomas

and lung tissue was, therefore, examined by four independent

pathologists. Following submission of these data to the Agency, the

lung tissue was then reexamined by two additional pathologists, one

designated by the registrant and another by the Agency. The findings of

these pathologists were very similar and were within the historical

incidence of adenomas and carcinomas. According to one pathologist,

the incidence of pulmonary adenomas and carcinomas in the control,

low-dose, mid-dose and high-dose male rats was 2.9, 5.7, 2.8 and 5.8%,

respectively. The corresponding incidences for the female groups were

0, 1.4, 2.8 and 0%, respectively. According to another pathologist, the

incidence of pulmonary adenomas and carcinomas in these groups was

2.9, 5.7, 4.3 and 5.8%, respectively (males) and 0, 1.4, 2.8 and 2.8%,

respectively (females). Based on these findings, paraquat did not appear

to be carcinogenic in the lungs of rats. 

There was a higher incidence of squamous cell carcinomas in the

head region (middle ear, hard palate, head tissue and skin), an

uncommon tumor, but the incidence was generally low and doseunrelated. The incidence of these carcinomas (combined) was 2.1, 4.3,

0 and 8.6% in the control, low-dose, mid-dose and high-dose male

groups respectively. The corresponding incidences for the female

groups were 0, 0, 4.3 and 2.9%, respectively. All of these carcinomas

occurred during the second year of study. The incidence of benign

pheochromocytomas in the adrenal medulla and perifollicular adenomas

and carcinomas in the thyroid was also increased in the high-dose male

rats. However, the relationship of these neoplasms to treatment was

unclear and additional data were, therefore, requested to evaluate

adequately the carcinogenic potential of paraquat in tissues other than

the lungs. An independent pathologist, selected by the Agency,

reviewed slides from the head region and concluded (as did the

registrant) that there was no justification for combining squamous cell

carcinomas (which occurred in four different sites of the head) for

assessment purposes. According to the pathologists (EPA's and the
21

registrant's), the skin and oral and nasal cavities have different

morphology and physiology, and separate biological functions, and

cannot be considered as a single organ in terms of assessment of

carcinogenic effects. When each of these sites was considered

independently, in the accepted manner for assessing tumor incidence, in

no instance was there a statistically significant difference between the

treated and control rats. Paraquat was, therefore, not carcinogenic in the

head region of the rat.

The incidence of pheochromocytoma in the adrenal gland of the

control, low-dose, mid-dose and high-dose male rats was 8.6, 12.6, 11.4

and 17.4%, respectively. The incidence of pheochromocytoma in the

historical control male rats ranged from 6.7% to 38.8% and this tumor

occurred in each of the eight studies from which historical data were

obtained. Considering the historical incidence, the incidence of

pheochromocytoma in this study (11.4- 17.4%) did not appear to be

paraquat-related because it fell within the range reported for the

historical control male rats.

The incidence of parafollicular adenomas and carcinomas in the

thyroid gland of the concurrent control, low-dose, mid-dose and highdose male rats was 11.9, 16.9, 13.6 and 18.8%, respectively. The

incidence of these neoplasms in the historical control male rats ranged

from 13.3% to 35.4%. Considering the historical incidence, the

incidence of parafollicular adenoma and carcinoma in the high-dose

male rats (18.8%), in this study, did not appear to be treatment-related. 

(MRIDs: 00138637, 00153223, 40202401, 40202402 and 41317401) 

Chronic Feeding/Carcinogenicity Study with Wistar Strain Rats

In another chronic feeding/carcinogenicity study, Wistar strain

rats, 62/sex/group, were fed diets containing technical grade paraquat

dichloride (purity: 98%) for 104 weeks. Based on the results of a

preliminary study, the doses of paraquat selected for this study were 0,

6, 30, 100 or 300 ppm, expressed as paraquat dichloride (nominal

concentrations). These values were equivalent to 0, 0.25, 1.26, 4.15 or

12.25 mg/kg/day, respectively (males) and 0, 0.30, 1.50, 5.12 or 15.29

mg/kg/day, respectively (females), expressed as paraquat dichloride

(analytical concentrations). The interim sacrifices, using 6

rats/sex/group, took place after 26 and 52 weeks of treatment. 

Paraquat was not carcinogenic in this study. Gross, nonneoplastic and neoplastic lesions were observed in various organs of
22

males and females, but did not appear to be treatment-related (either a

dose-relationship was lacking or the incidence was similar in the

controls and the paraquat-treated groups). The most frequent lesions

were observed in the following organs: (1) lungs (congestion, nodes,

peribronchiolitis, pneumonia and thickening of alveolar walls); (2) liver

(bile duct proliferation and fibrosis); (3) kidneys (rough surface and

nephritis); (4) pituitary (hypertrophy, hematoma and benign tumors); (5)

thyroid (benign tumors); (6) adrenals (cysts); (7) spleen (swelling); 

(8) mesenteric lymph node (swelling and inflammation); (9) testes and

ovaries (atrophy); (10) uterus (cysts and polyps); and (11) mammary

glands (cysts, adenomas, fibromas, fibroadenomas and

adenocarcinomas). (MRID 40218001) 

Chronic Feeding/Carcinogenicity Study with SPF Swiss-Derived Mice

Groups of SPF Swiss-derived mice (Alderley Park strain),

60/sex/dose, were administered paraquat dichloride (cation content:

32.7%) for 23 months (when mortality was approaching 80% in all

groups). The dose levels used in this study were 0 (two control groups),

12.5, 37.5 or 100/125 ppm, expressed as paraquat cation, and were

based on the results of two preliminary (28-day) studies (MRID

00087921 and 00087922). Assuming that, for a mouse, 1 ppm = 0.15

mg/kg/day, these doses corresponded to 0, 1.87, 5.6 or 15.0/18.7 mg of

paraquat cation, kg/day, respectively. Because no toxic signs appeared

after 35 weeks of dosing, the 100 ppm level was increased to 125 ppm

at week 36.

Nothing remarkable was observed in the low-dose male and

female group. Toxic signs observed in the mid-dose group included (1)

decreased food consumption (15-22%) in the females during weeks 56-

84, when compared with the controls; (2) decreased body weight gain

(5-7%) in the females during weeks 68-88; and (3) renal tubular

degeneration in the males (nonsurvivors, 40% and at the terminal

sacrifice, 38%). Toxic signs observed in the high-dose group included

(1) decreased food consumption in the males (7-15%) during weeks 4-

24 and in the females (8-34%) during weeks 5-88, when compared with

the controls; (2) decreased body weight gain in the females (12-45%)

during weeks 44-96; and (3) renal tubular degeneration in the males

(nonsurvivors, 65% and at the terminal sacrifice, 67%) and the females

(nonsurvivors, 50% and at the terminal sacrifice, 63%). A high

incidence of lenticular changes (degeneration, swelling and lens fibers

broken up into eosinophilic globules) were observed in the control and

paraquat-treated male and female mice, in both the nonsurvivors (81-
23

93%) and at the termination of the study (92-100%). This finding was

surprising, but special staining and fixation techniques were not used to

distinguish true pathological changes from artifacts in the eye tissue. 

The incidence of cataracts was low (males, 0-8% and females, 0-21%)

and dose-unrelated.

Paraquat was not carcinogenic in this study. Paraquat, at all

levels tested, had no effect on the incidence of benign and malignant

neoplasms in both male and female mice. The most prevalent benign

neoplasms were lung adenomas and Harderian gland adenomas in the

males and the females, pituitary adenomas in the females, and liver

nodules (Type A) in the males. The most prevalent malignant

neoplasms were lymphosarcomas in the males and females, and liver

nodules (Type B) in the males. 

Based on the above findings, the systemic NOEL for both sexes

is 12.5 ppm (1.87 mg/kg/day) and the systemic LOEL is 37.5 ppm (5.6

mg/kg/day), each expressed as paraquat cation. (MRID 00087924)

Chronic Feeding/Carcinogenicity Study with Groups of JCL:ICR Mice

Groups of JCL:ICR mice (Japan Clea Laboratories Co., Tokyo),

80/sex/dose, were administered paraquat dichloride (purity: 98%) for

104 weeks. Based on the results of a preliminary study (not submitted),

the doses of paraquat dichloride selected for this study were 0, 2, 10, 30

or 100 ppm (nominal concentrations). These values were equivalent to

0, 0.26, 1.31, 3.92 or 13.09 mg/kg/day, respectively (males) and 0, 0.26,

1.32, 3.82 or 13.03 mg/kg/day, respectively (females), expressed as

paraquat dichloride (analytical concentrations). The interim sacrifice,

using 10 mice/sex/group, took place after 26 and 52 weeks of treatment.

Treatment-related findings were observed only in the 100 ppm

group and included (1) increased mortality in the females; (2) decreased

total protein, erythrocytes, leukocytes, hemoglobin and hematocrit in

the males and females; (3) decreased polymorphonucleocytes in the

males and GPT and alkaline phosphatase activities in the females; (4)

decreased absolute and/or relative weights of adrenals, thyroid, liver and

urinary bladder in the males; (5) decreased absolute weight of brain in

the females; and (6) increased absolute and/or relative weights of

kidneys, lungs and heart in the males.

Paraquat was not carcinogenic in this study. Gross, nonneoplastic and neoplastic lesions were observed in various organs of the
24

male and female mice, but were not treatment-related. The most

frequent lesions were observed in the following organs: (1) lungs

(congestion, nodes, pneumonia, thickening of alveolar walls and

adenocarcinoma, all in both sexes); (2) liver (dilatation in the females

and tumors in the males); (3) kidneys (discoloration and coarse surface

in both sexes; dilatation of renal pelvis and cell infiltration in the males;

and nephropathy in the females); (4) spleen (swelling in both sexes); (5)

thymus (atrophy in both sexes and hypertrophy in the females); (6)

mesenteric lymph node (swelling and cell infiltration in both sexes); and

(7) eyes (corneal cell proliferation in both sexes and corneal

calcification in the females). Leukemia, amyloid degeneration and

leukemia cell infiltration were also observed frequently in the males and

females.

Based on the above findings, the systemic NOEL is 30 ppm of

paraquat dichloride (3.92 and 3.82 mg/kg/day, for males and females,

respectively); or 2.9 mg/kg/day (males) and 2.8 mg/kg/day (females),

expressed as paraquat cation. The systemic LOEL is 100 ppm of

paraquat dichloride (13.1 mg/kg/day, for both sexes); or 9.4 mg/kg/day,

expressed as paraquat cation. (MRID 40202403) 

The carcinogenic potential of paraquat was evaluated by the

Toxicology Branch Peer Review Committee (now Carcinogenicity Peer 

Review Committee) in 1986, 1988 and 1989, and by the FIFRA

Scientific Advisory Panel (SAP) in 1989.

The first Committee classified (July 9, 1986) paraquat as a

Category C carcinogen (limited evidence of carcinogenicity in animals),

without the Q (developing of a quantitative estimation of the *

carcinogenic potential). This decision was based on an increased

incidence of squamous cell carcinoma, an uncommon tumor, in the head

region (ear, skin, and oral and nasal cavities) of the high-dose male

Fischer 344 rats, when the treated animals were compared with the

concurrent or the historical controls (Study No. 82/ILY 217/328; MRID

00138637). The registrant contended that those tumor sites should not

be combined and an independent laboratory, which re-evaluated the

data, agreed with the registrant. When each of these sites was

considered separately, there was no statistically significant difference in

the incidence of squamous cell carcinomas between the treated and

control rats.

Considering the above findings and the subsequent (negative)

carcinogenicity studies with rats and mice (MRIDs 40218001 and
25

40202403, respectively), the second Committee placed paraquat in

Category E (no evidence of carcinogenicity in animal studies) on June

15, 1988.

The Federal Insecticide, Fungicide and Rodenticide Act (FIFRA)

SAP met on February 15, 1989 and, considering a squamous cell

carcinoma in the nasal cavity of two high-dose rats as an equivocal

evidence of carcinogenicity, placed paraquat in Category D. However,

the SAP also commented that further testing was not required and that

endpoints other than carcinogenicity were more relevant for the

regulation of paraquat.

 

The third Toxicology Branch Peer Review Committee met on

March 15, 1989 and decided to retain the Category E carcinogenicity

classification for paraquat.

e. Developmental Toxicity

The Agency has received and reviewed four developmental

toxicity studies as are detailed below.

Developmental Toxicity Studies with Alderley Park, Wistar-Derived

Rats

In a developmental toxicity study, paraquat dichloride (38.2%

purity as paraquat ion content) was administered to 24 female Alderley

Park, Wistar-derived (Alpk:APfSD) rats/dose by gavage in deionized

water at dose levels of 0, 1, 3, or 8 mg paraquat ion/kg/day from days 7

through 16 of gestation. The developmental NOEL is 8 mg paraquat

ion/kg/day (HDT). (MRID 43964701) 

No maternal or developmental effects were observed in the

study.

The maternal NOEL is 8 mg paraquat ion/kg/day (HDT).

In another study, paraquat dichloride (purity: 100%) was

administered by gavage in 0.5% aqueous Tween 80 to groups of 29-30

Alderley Park SPF rats at dose levels of 0, 1, 5 or 10 mg/kg/day,

expressed as paraquat cation, from gestation day 6 through 15. The test

solutions were administered in a volume of 1 ml/100 g of body weight. 

Control females received the same volume of 0.5% Tween 80 alone.

Females were observed for changes in appearance or behavior and body
26

weights were determined at intervals during gestation. The rats were

sacrificed on gestation day 21 and reproductive observations were made

and uteri examined for live fetuses and intra-uterine deaths. Fetuses

were weighed, sexed, and examined for external, visceral and skeletal

alterations. Doses used in this study were based on the results of a

range-finding study in which doses (paraquat cation) of 5, 10, 20 or 40

mg/kg/day were tested and which was briefly summarized in this

submission. (In the range-finding study, all rats died in the 40 mg/kg

group and one rat died in the 20 mg/kg group. The nonsurvivors had

dark red lungs or dark red patches on the lungs). 

Maternal toxicity was reported at the two highest doses and

included (1) clinical signs such as piloerection, thin and hunched

appearance, and decreased body weight gain (24% and 29% less than

controls for the mid-dose and high-dose groups, respectively); (2)

deaths of 6 high dose animals versus none in the control group; (3)

respiratory distress in 3 high-dose females; and (4) histopathological

findings in the lungs (edema in the alveoli and polymorph infiltration)

and in the kidneys (degenerative changes in the proximal tubules) of the

nonsurvivors. 

Treatment-related developmental effects (delayed ossification in

the forelimb and hindlimb digits) were observed only in the mid-dose

and high-dose groups. It was reported that 41.9% of the control group

fetuses had good forelimb digit ossification compared with 28.8% and

23.0% of the mid-dose and high-dose fetuses, respectively. Similar

results were noted for the hindlimb digit ossification.

Based on the above findings, the NOEL and LOEL for maternal

toxicity are 1 mg/kg/day and 5 mg/kg/day, respectively, expressed as

paraquat cation. The NOEL and LOEL for developmental toxicity are

also 1 mg/kg/day and 5 mg/kg/day, respectively. (MRID 00113714) 

The overall maternal NOEL for the rat is 3 mg/kg/day based on

the results from the two previously summarized studies (MRID's

43964701 and 00113714).

Developmental Toxicity Study with Crl:CD1 (ICR) BR Mice

In another developmental toxicity study, paraquat dichloride

(38.2% purity as paraquat ion content) was administered to 26 female

Crl:CD1 (ICR) BR mice/dose by gavage in water at dose levels of 0,
27

7.5, 15 or 25 mg paraquat ion/kg/day from days 6 through 15 of

gestation.

At 25 mg/kg/day, paraquat is maternally toxic, inducing clinical

signs (piloerection, labored respiration, hunched posture, hypothermia,

hypoactivity and/or pale extremities and eyes); death; decreases in body

weight and body weight gain (p < 0.01); dark red lung lobes; increases

in lung with trachea and kidney weights and a possible decrease in

pregnancy rate. No maternal effects were observed at either 7.5 or 15

mg paraquat ion/kg/day.

At 25 mg/kg/day, significant decreases in mean fetal weights

were observed. In addition, skeletal effects were observed which

included increases in the number of litters with retarded ossification of

the occipital (p < 0.05), the number of fetuses and litters with 6 caudal

centra (p < 0.01 and < 0.05 for fetuses and litters, respectively), the

number of litters with uni- or bilateral extra 14th ribs (p < 0.05) and the

number of fetuses and litters with non-ossified astragalus in the

hindlimb (p < 0.01 and < 0.05 for fetuses and litters, respectively). No

other developmental effects were observed at this dose level. No

developmental effects were observed at either 7.5 or 15 mg paraquat

ion/kg/day.

The maternal LOEL is 25 mg paraquat ion/kg/day, based on

clinical signs, death, decreases in body weight and body weight gain,

dark red lung lobes, increases in lung with trachea and kidney weights

and a possible decrease in pregnancy rate. The maternal NOEL is 15

mg/kg/day.

The developmental LOEL is 25 mg paraquat ion/kg/day, based

on decreases in mean fetal weights and retarded ossification of the

occipital, increases in the number with 6 caudal centra, increases in

the number with uni- or bilateral extra 14th ribs and increases in the

number with non-ossified astragalus in the hindlimb. The developmental

NOEL is 15 mg/kg/day. (MRID 43949902)

Developmental Toxicity Study with SPF Alderley Park Mice

In another study, paraquat dichloride (purity: 100%) was

administered by gavage in 0.5% aqueous Tween to groups of SPF

Alderley Park mice at dose levels of 0, 1, 5 or 10 mg/kg/day, expressed

as paraquat cation, from gestation day 6 through 15. The test solutions

were administered in a volume of 0.1 ml/10 g of body weight. Control
28

animals received Tween 80 alone. The study was started with 120

mated mice, 30/dose. Because several mice in each group either were

not pregnant, died or littered (and were excluded from the study),

insufficient litters were available for examination. An additional 42

females were, therefore, mated 4-5 weeks after the first matings and

were allocated to the four test groups as follows: 6 each to the control

and the low-dose groups, 20 to the mid-dose group and 10 to the highdose group. The mice were sacrificed on gestation day 18. Maternal

parameters examined included body weight, clinical observations,

reproductive observations (resorptions, viable fetuses and number of

implantations), necropsy, and histopathology on the following tissues:

lungs, kidneys, heart, spleen, liver, ovaries, uterus and placenta. Fetuses

were weighed, sexed, and examined for external, visceral and skeletal

alterations. Doses used in this study were based on the results of a

range-finding study in which doses (paraquat cation) of 5, 10, 20 or 40

mg/kg/day were tested and which is briefly summarized in this

submission. (In the range-finding study, all mice died in the 40 mg/kg

group and one mouse died in the 10 mg/kg group. The nonsurvivors

had dark red lungs or dark red patches on the lungs). 

The only possible treatment-related maternal toxicity observed

was a reduction in body weight gain in the mid-dose group (14%,

P<0.05) and the high-dose group (11%). However, in the range-finding

study with nonpregnant females, there was one death at 10 mg/kg/day. 

In addition, there was a statistically significant increase in the number of

litters and fetuses with partially ossified 4th sternebrae in the high-dose

group. There was also a statistically significant increase in trend. This

is indicative of maternal toxicity. Gross necropsy and histopathology of

maternal tissues revealed no treatment-related abnormalities. The only

treatment-related developmental effect was the increase in the number

of litters and fetuses with partially ossified 4th sternebrae in the highdose group. Based on these findings, the NOEL and LOEL for maternal

toxicity are 5 mg/kg/day and 10 mg/kg/day, respectively, expressed as

paraquat cation. The NOEL and LOEL for developmental toxicity are

also 5 mg/kg/day and 10 mg/kg/day, respectively. (MRID 00096338)

f. Reproductive Toxicity

Wistar-derived Alderley Park strain of rats, 15 males and 30

females/group, were fed technical grade paraquat dichloride (cation

content: 32.7%) for 11-12 weeks before they were mated to produce F ,1

F2 and F3 A litters, and subsequently F1, F2 and F3 A litters. The

following levels of paraquat cation were fed in the diet: 0, 25, 75 or 150
29

ppm. Assuming that, for an older rat, 1 ppm = 0.05 mg/kg/day, these

doses correspond to 0, 1.25, 3.75 or 7.5 mg of paraquat cation/kg/day,

respectively. These doses are identical to those used in the chronic

feeding/carcinogenicity study with rats (MRID 00138637).

Paraquat, at all levels tested, had no effect on body weight gain,

food consumption and utilization, fertility and length of gestation of the

F0, F1 and F2 parents. However, there was a high incidence of mortality

(27-43%) in the high-dose F0, F1 and F2 females, due mostly to severe

lung damage caused by paraquat. The incidence of lung injury (red or

purple discoloration, congestion, edema, fibrosis, hyaline membrane

formation, inflammatory cell infiltration and/or hyperplasia) ranged

from 27% to 35%. There was also an increased incidence of alveolar

histiocytosis in the lungs of the mid-dose and high-dose male and

female parents. In the case of the F0, F1 and F2 females, the incidence

was 28-40% (control groups), 28-54% (low-dose groups), 62-80%

(mid-dose groups) and 80-100% (high-dose groups). The

corresponding incidences for the males were 11-30%, 0-13%, 10-71%

and 50-86%, respectively.

 

The most frequent histological findings at the termination of the

study were hydronephrosis, nephrocalcinosis, lung congestion and/or

alveolar hemorrhage, perivascular inflammatory cell infiltration in the

lungs, focal accumulation of lymphocytes in the liver, and hypoplasia,

atrophy and/or necrosis of the testes. However, the incidence of these

findings was not dose-related. 

Based on the above findings, the NOEL and LOEL for systemic

toxicity are 25 ppm (1.25 mg/kg/day) and 75 ppm (3.75 mg/kg/day),

respectively, expressed as paraquat cation. The NOEL for reproductive

toxicity is 150 ppm (7.5 mg/kg/day; HDT), expressed as paraquat

cation. (MRID 00126783) 

g. Mutagenicity

Paraquat was weakly positive in the mouse lymphoma cell assay,

but only with metabolic activation (in the presence of Aroclor 1254-

stimulated rat hepatic microsomes, S-9, plus appropriate cofactors). It

induced forward mutation in the L5178Y mouse lymphoma cell line as

monitored by cell growth in the presence of trifluorothymidine (TFT). 

Mouse lymphoma L5178Y cells were exposed for 2 hours to paraquat

dichloride (technical grade; active ingredient content: 45.7%) at

concentrations ranging from 31.25 to 1000 ug/mL, both in the presence
30

and absence of the S-9 mix. Five separate experiments were performed. 

Positive controls used were ethyl methane sulfonate (EMS) and

benzo(a)pyrene [B(aP]. Concentration-related cytotoxicity to paraquat

was observed in all experiments. Concentrations of 500-1000/mL were

either severely cytotoxic or lethal. This study satisfies Guideline

requirements for genetic effects, Gene Mutations. (MRID 00152690) 

 

Paraquat dichloride (purity: 99%) was not mutagenic in the

Ames test using Salmonella typhimurium histidine-requiring strains

TA1535, TA1538, TA98 and TA100, with and without metabolic

activation. The concentrations of paraquat dichloride tested were 0.16,

0.8, 4, 20, 100, 500, 2500 and 5000 ug/plate. Concentrations above 100

ug/plate were cytotoxic. Positive controls used were N-2-

acetylaminofluorene (AAF), 2-nitrofluorene (2NF), 2-(1-chloro-2-

isopropylaminoethyl) naphthalene (CPE) and meclorethamine (nitrogen

mustard). This study satisfies Guideline requirements for genetic

effects, Gene Mutations. (MRID 00100441) 

 

Paraquat was weakly positive in the mammalian cells (human

lymphocytes) in culture cytogenetic assay, with and without metabolic

activation (S-9 mix). The lymphocytes were obtained from two healthy

donors, male and female. The concentrations of paraquat dichloride

(analytical grade; active ingredient content: 99.6%) tested ranged from

0.75 to 3500 ug/mL. Positive controls used were mitomycin-C (MC)

and cyclophosphamide (CP). Severe cytotoxicity was observed in

cultures exposed to the highest concentration of paraquat tested (3500

ug/mL). Concentration-related decreases in mitotic indices were

recorded at 125-2500 ug/mL. Increases in chromosome damage were

found in non-activated cultures exposed to the 1250 ug/mL and higher

levels of paraquat. In the presence of S-9, statistically significant

(P<0.01) increases in chromosome damage were observed at 1750

ug/mL in the case of one donor and at 2500 ug/mL in the case of

another donor. This study satisfies Guideline requirements for genetic

effects, Structural Chromosome Aberrations. (MRID 00152692) 

Analytical grade paraquat dichloride (active ingredient con-tent:

99.4%) was positive in the sister chromatid exchange (SCE) assay, with

and without metabolic activation. Duplicate mono- layer cultures of

DON cells (derived from Chinese hamster lung fibroblasts) were

exposed for 3 hours to paraquat dichloride ranging in concentration

from 1.2 to 2470 ug/mL, with and without the metabolic activation

system (S-9). Cell cultures were then incubated with brom

deoxyuridine for 20 hours, incubated with cholchicine for 2 hours and
31

then processed for microscope slide scoring for SCE according to

standard procedures. Mitomycin C (MC) and cyclophosphamide (CP)

were used as positive controls. This study satisfies Guideline

requirements for genetic effects, Structural Chromosome Aberrations. 

(MRID 00152695) 

Technical grade paraquat dichloride (cation content: 33%) was

negative for chromosomal aberrations in the bone marrow test system. 

Positive results were obtained with cyclophosphamide, a known

clastogen. In this study, Alderley Park Wistar-derived male and female

rats received by gavage single doses of paraquat dichloride and then

were sacrificed for bone marrow sampling at 12, 24 or 48 hours after

treatment. The doses used, expressed as paraquat cation, were 0, 15, 75

or 150 mg/kg. Based on the results from a preliminary study, the 150

mg/kg dose approximated a maximum tolerated dose (MTD). This

study satisfies Guideline requirements for genetic effects, Structural

Chromosome Aberrations. (MRID 40202405)

No evidence of dominant lethal mutagenicity or suppression of

fertility was seen in the study with CD-1 mice. In this study, male mice

were administered paraquat dichloride (cation content: 28.3%) by

gavage for 5 consecutive days and then were mated with different

untreated female mice for 8 weeks. The doses of paraquat used were 0,

0.04, 0.4 and 4.0 mg/kg, expressed as paraquat cation. These doses

were based on the results of a preliminary study in which the 4.0 mg/kg

dose was the maximum tolerated dose (MTD). Mutagenic effects were

observed with positive controls, ethyl methane sulphonate (EMS) and

cyclophosphamide (CP). This study satisfies Guideline requirements

for genetic effects, Structural Chromosome Aberrations. (MRID

00100442)

Analytical grade paraquat dichloride (active ingredient content:

99.6%) did not induce unscheduled DNA synthesis in rat hepatocytes

exposed in vitro. Hepatocytes from an untreated male rat (Alderley

Park SPF albino) were allowed to attach to cover slips for 2 hours and

then were exposed for 19 hours to tritiated thymidine together with

paraquat dichloride at concentrations ranging from 10 to 10 M. -2 -9

Diethylnitrosamine (DEN) was used as a positive control. This assay

was repeated once using hepatocytes from another rat. This study

satisfies Guideline requirements for genetic effects classified as Other

Genotoxic Effects. (MRID 00152693) 
32

Technical grade paraquat dichloride (cation content: 33%) was

negative for unscheduled DNA synthesis in rat hepatocytes exposed in

vivo. Suspensions of hepatocytes were prepared from male Alderley

Park SPF albino rats dosed by gavage with paraquat dichloride, water

(controls) or 6BT (6-dimethylaminophenylazo-benzthiazole; positive

control). The single doses of paraquat dichloride used were 0, 45, 75 or

120 mg/kg and the rats were sacrificed at 4 and 12 hours after dosing. 

Two separate experiments were performed for each time point. The

selection of doses was governed by the need to evaluate paraquat at

adequate concentrations and that these doses should not induce toxicity

in the hepatocytes. No increase in unscheduled DNA synthesis was

observed at any dose of paraquat dichloride at either time point when

compared with concurrent negative controls, but positive results were

obtained with 6BT. Although hepatocytes from rats in the 120 mg/kg

group showed marked signs of toxicity, sufficient cells of normal

morphology were available to be examined for unscheduled DNA

synthesis. This study satisfies Guideline requirements for genetic

effects classified as Other Genotoxic Effects. (MRID 40202404) 

h. Metabolism

Paraquat was not metabolized by rats. After oral administration

(gastric intubation) of single doses of paraquat dichloride or

dimethylsulfate to Wistar strain male and female rats, most of the

administered radioactivity (69-96%) was excreted in feces as unchanged

paraquat. After subcutaneous injection of these compounds,

unchanged paraquat appeared mostly in urine (73-96% of the

administered radioactivity). Paraquat used in this study (radiochemical

purity: 99-100%) was labeled with 14-C in the methyl groups. The

doses used for gastric intubation ranged from 0.5 to 50 mg/kg and for

subcutaneous injection, from 12.5 to 24 mg/kg. Most of the

radioactivity was detected in feces within 2-3 days after dosing and in

urine, within 1 day after dosing.

Following oral administration of paraquat, up to 30% of the dose

appeared in feces in a degraded form. This was due to the microbial

degradation of paraquat in the gut. That microbial degradation of

paraquat occurred in feces was shown in an in vitro experiment in which

fecal homogenates were incubated with added paraquat for 24 hours. In

that experiment, 40-50% of paraquat was destroyed. However, a similar

experiment with sterilized fecal homogenates produced only minor loss

(trace amounts) of added paraquat. (MRID 00055107)
33

Paraquat was poorly absorbed after oral administration to rats,

dogs and mice. Once absorbed, paraquat was rapidly distributed to

most tissues but especially to lungs and kidneys. Tissues other than

lungs did not retain paraquat. (MRID 00138637, 00132474 and

40202403)

i. Neurotoxicity

Considering the chemical nature of paraquat and the fact that it

has not been shown to inhibit cholinesterase activities, does not produce

cholinergic-like toxic signs and does not affect morphology of the

central and peripheral nervous systems, the following studies are not

required: acute delayed neurotoxicity study in the hen (81-7); acute

(81-8 SS) and subchronic (82-5b or 82-7) neurotoxicity screening

battery studies in the rat; and developmental neurotoxicity study in the

rat (83-6). There is currently no evidence to suggest the need for these

studies.

j. Dermal Absorption

In a dermal absorption study with healthy adult male volunteers,

0.3% of the applied C-paraquat dichloride was absorbed through the 14

intact skin (forearms, and back of the hands and lower legs) during the

24-hour exposure period. (MRID 00153439).

k. Poisoning Incidents

From 1985 through 1994, there were 17 paraquat-related deaths

reported to Poison Control Center’s national database from oral

ingestion. Most of the fatal oral ingestions (13 out of 17) have been

related to suicidal incidents. Of the four remaining cases, two were

unknown as to intent and two were accidental ingestions. These two

accidental ingestions occurred when paraquat end-use products were

formulated into a brown liquid which could have been mistaken for a

cola-type of soft drink (prior to 1988). However, since 1988 the

manufacturer has added an emetic (a substance that induces vomiting), a

stenching agent and changed the color (to blue), to try and prevent the

accidental and intentional ingestions from occuring. U.S. Poison

Control Center data, show a decline of almost 50 percent when

comparing the proportion of all pesticide exposures due to paraquat

ingestion for the four years pre- and post 1988.
34

Dermal exposure to paraquat usually results in minor skin or eye

irritation. Rarely, with heavier exposures resulting from misuse, more

serious effects may occur such as blistered or ulcerated skin, loss of

fingernails, skin burns, ulcers of the mouth, nosebleeds, and protracted

or even permanent blindness. These more serious effects typically

result when protective clothing is not worn, skin has abrasions or open

cuts, and/or when extensive exposure is allowed to persist without

washing. The label currently warns against these hazards. Heavy,

prolonged dermal exposure, as from a leaking knapsack type of sprayer,

can result in severe poisoning and, rarely, even death. Six such deaths

have been reported outside of the United States when workers failed to

follow label requirements for proper hygiene.

l. Toxicological Endpoints of Concern Identified for Use in

Risk Assessment

Reference Dose (RfD)

On July 20, 1995, the Agency's Reference Dose (RfD)/Peer

Review Committee verified the reference dose (RfD) for paraquat which

was last revised on February 1, 1991. The Committee recommended

that the already established RfD, 0.0045 mg/kg/day (expressed as

paraquat cation), be retained. This value was based on the systemic

NOEL of 15 ppm (0.45 mg/kg/day) from the 1-year dog feeding study

(MRID 00132474) and the uncertainty factor (UF) of 100. Chronic

pneumonitis was observed at the next dose of paraquat tested, 30 ppm 

(0.93 mg/kg/day), expressed as paraquat cation. The WHO RfD (ADI),

which was last reviewed in 1986, is 0.0040 mg/kg/day, expressed as

paraquat cation.

The following endpoints were determined by the Agency's

Toxicology Endpoint Selection Committee (TESC) on July 25, 1995:

Acute Dietary (1 day)

An acute dietary (1 day) risk assessment is not required. No data

are available that suggest a need for an acute dietary endpoint. 

An examination of the data did not provide any toxicological

endpoints that could have resulted from a single acute dietary exposure

when paraquat is used as labeled. In addition, there are many tolerances

for paraquat on raw agricultural commodities (RAC) and virtually all of
35

them are at the detection limit. Therefore, the TESC felt that there

would not be any acute dietary problems or concerns with paraquat.

Short Term Occupational Exposure (1-7 days)

The Toxicology Endpoint Selection/Peer Review Committee

indicated inhalation endpoints should be used for risk assessment only

in cases in which the spray particles are of a respirable size. This

endpoint was based on the NOEL and LOEL for subchronic (3 weeks)

inhalation toxicity, for both sexes, of 0.01 ug/L and 0.10 ug/L,

respectively, expressed as paraquat cation. This endpoint will not be

used for risk assessment unless the particle size is small enough to be

respirable (such as aerosol spray). (MRID 00113718)

For all other use scenarios (such as agricultural applications), a

"dermal endpoint" is used: NOEL of 3 mg/kg/day, expressed as

paraquat cation, based on maternal and developmental toxicity effects:

unscheduled deaths, thin and hunched appearance, decreased body

weight gain, and histological changes in the lungs and kidneys of the

nonsurvivors. Exposure by the dermal route, obtained by extrapolating

data (NOEL) from a combination of two rat developmental toxicity

studies and correcting for dermal absorption (0.3%), is appropriate for

short term occupational and residential exposure. (MRIDs 00113714,

43964701 and 00153439).

Intermediate Term Occupational (1 week to several months)

The endpoint used is the same as for the Short Term

Occupational or Residential Exposure (above).

Chronic Occupational Exposure (Longer Than Several Months)

The endpoint and dose for use in risk assessment: 0.45

mg/kg/day, expressed as paraquat cation (NOEL for systemic toxicity,

based on the severity and extent of chronic pneumonitis in both sexes),

in the one-year dog feeding study. (Guideline No.: 83-1b, MRID: 

00132474)

This risk assessment is not required as there are no chronic

occupational nor residential exposure scenarios for the use of paraquat.

Cancer Classification and Basis: 
36

The Agency has classified paraquat as a Group E carcinogen

(evidence of non-carcinogenicity for humans), based on a lack of

evidence of carcinogenicity in acceptable studies with two animal

species, rat (Guidelines 83-1a/83-2a; MRIDs 00138637, 00153223,

40202401, 40202402, 41317401, 40218001) and mouse (Guidelines 83-

2b; MRIDs 00087924, 40202403), by the Toxicology Branch Peer

Review Committee (now Carcinogenicity Peer Review Committee) on

June 15, 1988, and (again) on March 15, 1989.

2. Exposure Assessment

a. Registered Uses

Paraquat dichloride is currently registered for the control of

broadleaf weeds and grass in agricultural and non-agricultural areas. It

is used as a preplant or preemergence herbicide on vegetables, grains,

cotton, grasses, sugar cane, peanuts, potatoes, and on areas for tree

plantation establishment. Paraquat is applied as a directed spray

postemergence herbicide around fruit crops, vegetables, trees, vines,

grains, soybeans, and sugar cane. It is used for dormant season

applications on clover and other legumes, and for chemical fallow. It is

also used as a desiccant or harvest aid on cotton, dry beans, soybeans,

potatoes, sunflowers, and sugar cane. It is use as a post harvest

desiccant on staked tomatoes, and on pine trees to induce resin soaking.

Paraquat dichloride is applied by aerial, groundboom, backpack

sprayer, and low pressure handwand.

A soluble concentrate/liquid (SC/L) is the sole paraquat

formulation type registered for all uses. This formulation may be

applied to crops pre-plant, at planting, pre-emergence (broadcast or

band), post-emergence (broadcast, band, split, directed, or spot), postharvest (as a pre-harvest desiccant or harvest aid), and for suckering and

stripping of hops.

i. Agricultural

Paraquat dichloride end-use products (EPs) with

food/feed uses registered to Zeneca Ag Products are listed

below.

 EPA Reg. No. Acceptance Date Formulation Class Product Name

 10182-103 4/4/95 1.5 lb/gal SC/L Gramoxone® Super Herbicide a
 EPA Reg. No. Acceptance Date Formulation Class Product Name

37

 10182-111 4/4/95 2 lb/gal SC/L Cyclone® Herbicide b c

 10182-120 4/4/95 29.42% SC/L Surefire® Herbicide c

 10182-280 4/4/95 2.5 lb/gal SC/L Gramoxone® Extra Herbicide d,e

 10182-372 4/4/95 3 lb/gal SC/L Cyclone® Concentrate Herbicide c

Including SLN Nos. LA870004, LA870005, OH880002, PA870002, SC820011, and TN940007. a

Including SLN Nos. AR820020, NC820010, NM940003, OK940004, SC820024, TX810032, and TX940011. b

The 2 and 3 lb/gal SC/L (EPA Reg. Nos. 10182-111 and 10182-372) and the 29.42% SC/L (EPA Reg. No 10182-120) formulations are c

coded by REFs as emulsifiable concentrate (EC) formulations. However, these products were previously identified as SC/L formulations

in the Registration Standard Update.

Including SLN Nos. AL940005, AR950002, CA910021, CA910022, CA910023, CA910024, CA910031, CA910036, CA920006, d

CT900001, DE940002, FL900009, FL910004, FL910006, GA940006, HI910001, HI910010, HI920008, ID920010, ID920011, ID930006,

LA940007, MI910009, MN900004, MT940005, NH900001, NH920001, NJ900005, NV910002, NV910003, OH910001, OR910023,

OR910024, OR930009, OR930019, PA900001, SD940005, TN940008, VA930006, VA940012, WA910044, WA910048, WA930014,

WA940037, WA950007, and WI900004.

The 2.5 lb/gal SC/L formulation (SLN No. MN940006) was unavailable for review; the registration jacket did not contain a label. e

ii. Non-agricultural

The non-agricultural uses of paraquat are for nonselective

weed control on conservation reserves and non-crop areas such

as public airports, storage yards and electric transformer stations. 

One formulation of paraquat dichloride, ICI Spot Weed

and Grass Control (EPA Reg. No. 10182-114), was intended for

homeowner use and was packaged as a ready-to-use pressurized

spray (aerosol) containing 0.276 percent active ingredient. It

was labelled to control weeds and grasses around walks,

driveways, trees, shrubs, and flower beds. However, this

product has never been sold in the U.S. even though it was

registered and has been voluntarily cancelled at the request of

the registrant because of unacceptable risk to the applicator

identified through this reregistration process. 

b. Dietary Exposure

The Residue Chemistry data base for paraquat is substantially

complete. The registrant is required to submit data for a few

outstanding data requirements. Sufficient data are available to reassess

the adequacy of the majority of the established tolerances for paraquat

as listed in the relevant sections of 40 CFR. The Agency is requiring

that the tolerance for residues in or on several of the crops be changed,

as detailed in section IV of this document, Tolerance Reassessment

Summary Table.

GLN 171-4 (a): Plant Metabolism
38

For purposes of reregistration and risk assessment, the

qualitative nature of the residue in plants is adequately understood based

on studies depicting the metabolism of paraquat in carrots and lettuce

following pre-emergence treatment and in potatoes and soybeans

following desiccant treatment. The residue of concern in plants is the

parent, paraquat; the current tolerance expression for plant commodities,

as defined in 40 CFR §180.205(a) and (b), 185.4700, and 186.4700, is

adequate.

In plant metabolism studies reflecting pre-emergence treatment,

the total radioactive residues (TRR) were 0.0048 ppm in carrot root and

0.0034 ppm in lettuce leaf samples following a single pre-emergence

application at 13x the maximum rate of 1 lb cation/A. These data

suggest that radioactive residues of paraquat are not readily taken up

from the soil in significant quantities by these crop commodities

following this mode of treatment. No further residue characterization

and identification was conducted on these samples because of the low

magnitude of radioactivity obtained.

In plant metabolism studies reflecting desiccant treatment, the

total radioactive residues were 0.075 and 0.087 ppm in potatoes, 0.652

and 0.841 ppm in soybeans, and 506.3 and 768.5 ppm in soybean

foliage following a single foliar desiccant application at 6x the

maximum seasonal rate of 1.25 lb cation/A for potatoes and 29x the

maximum single application rate of 0.25 lb cation/A for soybeans). 

Paraquat cation was the major C-residue identified, and accounted for 14

91% of the total radioactivity in potatoes, 84% of the total

radioactivity in soybeans, and virtually all of the total radioactivity in

soybean foliage. Other minor metabolites found in soybean foliage

were QINA (quaternary iso-nicotinic acid), a photodegradant and

monoquat (1-methyl-4,4'-bipyridinium ion), each at 0.3% of TRR.

GLN 171-4 (b): Animal Metabolism

For purposes of reregistration and risk assessment, the

qualitative nature of the residue in animals is adequately understood

based on the combined results of studies conducted with ruminants

(goats and cows), swine, and poultry. The residue of concern in eggs,

milk, and poultry and livestock tissues is the parent, paraquat; the

current tolerance expression for animal commodities, as defined in 40

CFR §180.205(a), is adequate.
39

In a ruminant metabolism study, a lactating goat was dosed with

ring-labeled [ C]paraquat dichloride at 103 ppm in the diet for seven 14

days. The total radioactive residue, expressed as ppm paraquat, was

0.02-0.03 ppm in fat (peritoneal and subcutaneous), 0.08-0.12 ppm in

muscles (fore- and hind-quarter), 0.56 ppm in liver, and 0.74 ppm in

kidney. The maximum total radioactivity in milk increased daily to a

maximum of 0.0092 ppm paraquat ion equivalents four hours before

slaughter; 75.7% of the TRR of this sample was found to be paraquat. 

In edible tissues, paraquat accounted for the majority of the identified

residues including 49-120% of TRR in fat, 90-100% of TRR in

muscle, 48% of TRR in liver, and 95% of TRR in kidney. Other

metabolites that were identified in tissues were the monopyridone of

paraquat (1,2-dihydro-1,1'-dimethyl-4,4'-bipyridinium ion) which

accounted for 3.2% of TRR in liver and monoquat which accounted for

3.4% of TRR in liver and 6.5% of TRR in peritoneal fat.

A pig metabolism study reflecting use of ring-labeled

[ C]paraquat and a feeding level of 2.44 ppm is also available. Total 14

radioactive residues were 0.20 ppm paraquat equivalents in liver, 0.38

ppm in kidney, 0.05 ppm in muscle, and 0.01 ppm in fat. Paraquat was

found to comprise 70% of TRR in liver, 101% of TRR in kidney, 95%

of TRR in muscle, and 106% of TRR in fat. Liver tissue, the only tissue

analyzed for residues other then paraquat, was found to contain

monoquat at 4% of TRR.

In a poultry metabolism study, laying hens were dosed with ringlabeled [ C]paraquat at 30 ppm in the diet for ten consecutive days. 14

Radioactive residues were found in all examined tissues (including

liver, abdominal and subcutaneous fat, and leg and breast muscle). 

Paraquat was the major residue ( 80-98% of TRR) identified in all

poultry tissues; monoquat was a minor metabolite ( 4% of TRR each)

in liver and kidney. Virtually all of the radioactivity in the yolk was

identified as paraquat; no analysis of albumen was reported.

GLN 171-4 (c) and (d): Residue Analytical Methods-Plants and

Animals

The requirements for residue analytical methods are partially

fulfilled for purposes of reregistration, pending submission of

supporting raw data for the radiovalidation study of the method for plant

commodities. Acceptable methods are available for enforcement and

data collection purposes both in plant and animal commodities.
40

Methods for determination of residues in/on plant commodities: 

The Pesticide Analytical Manual (PAM Vol. II) lists a

spectrophotometric method, designated as Method I (LOD = 0.01-0.06

ppm), as available for the enforcement of tolerances in plant

commodities. Several modifications of Method I have been developed

for analysis of specific crops, and these modified methods were used for

data collection. Samples from field trial and processing studies,

submitted to fulfill reregistration requirements, were analyzed for

residues of paraquat using Methods 1B, 2B, 3A, and 3B, and Methods

RM-8, RM-8-9, RM-8-10, and RM-8-11. Method I along with its

modifications all include extraction in acid solution, adsorption of

residues on a cation-exchange resin, elution with saturated ammonium

chloride, reduction with sodium dithionite to give a blue-colored

solution of free radical, and detection by spectrometry. The registrant

provided adequate method validation data to verify the suitability of

Methods 1B, 2B, 3A, and 3B for data collection.

In conjunction with recently submitted plant metabolism studies,

the registrant has provided radiovalidation data for Method 1B using

radiolabeled samples. The Agency tentatively concluded that Method

1B adequately recovers paraquat cation residues from samples of

potatoes and soybeans treated with [ C]paraquat. The registrant has 14

recently submitted representative spectra and other supporting raw data

from the radiovalidation study; upon the Agency’s review of this

additional information, the requirements for residue analytical methods

for plant commodities will be considered fulfilled for reregistration

purposes.

Methods for determination of residues in animal commodities: 

The Pesticide Analytical Manual (PAM Vol. II) lists a

spectrophotometric method, designated as Method Ia (LOD = 0.005

ppm), as available for the enforcement of tolerances in animal

commodities. The registrant has submitted descriptions and adequate

independent laboratory validation data for a high-performance liquidchromatography method (HPLC; designated as Method 4B) to

determine paraquat residues in animal tissues and eggs. The method has

been validated by the Agency’s Beltsville laboratory, and the registrant

is required to make minor changes in the method write-up.

Multiresidue Methods: The FDA PESTDATA database (dated

1/94) does not have an entry for paraquat. The existing FDA

multiresidue methods are not likely to recover paraquat residues owing

to its ionic nature.
41

GLN 171-4 (e): Storage Stability

Provided that the final results of storage stability studies for

cabbage, carrots, and milk are acceptable, the requirements for storage

stability data will be considered fulfilled for reregistration purposes;

these requested studies have recently been submitted to the Agency

(MRID#'s 43954003 and 43954004) and will be reviewed in the near

future. Although the storage stability of paraquat has not been

investigated in any oilseed or nut and the storage stability data on

processed commodities are rather limited, no additional storage stability

data are required for reregistration purposes provided the recently

submitted stability study data are adequate; in practically all examined

cases, paraquat residues were found to be stable at the maximum storage

intervals tested. The available data for corn grain may be translated to

oilseeds.

GLN 171-4 (k): Magnitude of the Residue in Plants

Pending required label amendments and/or revised tolerances,

the reregistration requirements for magnitude of the residue in/on plants

are fulfilled for the following commodities: acerola; almond hulls;

apples; apricots; asparagus; avocados; bananas; barley grain, forage,

and straw; beans, dry and succulent; beans, forage, hay, and straw;

broccoli; cabbage; cacao beans; carrots; cassava; cauliflower; cherries;

Chinese cabbage; citrus fruits group; coffee beans; collards; corn, field,

grain; corn, field, forage and fodder; corn, pop, grain; corn, pop, fodder;

corn, sweet (K + CWHR); corn, sweet, forage and fodder; cottonseed;

cucurbit vegetables group; figs; fruiting vegetables (except cucurbits)

group; grass, rangeland, forage; grass, pasture, forage; grass, pasture,

hay; guar; guava; hops, dried; kiwifruit; lentils; lentils, forage; lettuce;

mint tops; nectarines; non-grass animal feeds group, forage; non-grass

animal feeds group, hay; olives; onions, dry bulb and green; papayas;

passion fruit; peanuts; peanuts, hay and hulls; pears; peas, pigeon; peas,

succulent; peas, hay and vines; pineapples; peaches; pistachios; plums;

potatoes; rhubarb; rice, grain and straw; safflower, seed; small fruits and

berries group; sorghum, grain; sorghum, forage and fodder; soybeans;

soybeans, forage, and hay; strawberries; sugar beets, roots and tops;

sugarcane; sunflower seeds; taniers; taro corms; tree nuts group; turnips,

roots and tops; tyfon; wheat grain, forage, and straw; and yams. 

Adequate field trial data depicting residues of paraquat following

treatments according to the maximum registered use patterns have been

submitted for the commodities listed above or have been translated

where appropriate.
42

Table I (OPPTS 860.1000) recognizes barley hay, cotton gin

byproducts (formerly called gin trash), and wheat hay as raw

agricultural commodities (RACs). Residue data are now required for

these RACs, and appropriate tolerances should be proposed once

acceptable data have been submitted and evaluated. The required data

for wheat hay may be translated to barley hay. 

Table I of OPPTS 860.1000 no longer recognizes cotton forage,

popcorn forage, pineapple forage, sorghum hay, safflower forage,

sorghum silage, and sugarcane forage as RACs. Therefore, no residue

data are required for these commodities and tolerances need not be

established. In addition, Table I no longer recognizes fresh hops, hop

vines, lentil hay, and peanut vines as RACS; therefore, the established

tolerances for these commodities will be revoked.

The registrant has expressed an intention to petition the Agency

for the revocation of the established tolerances for oat grain and rye

grain since the registrant claims there are no longer any registered uses

of paraquat on these commodities. Therefore, the tolerances for oat

grain and rye grain will be revoked.

No residue data or tolerance currently exists for taro foliage. 

The registrant must submit field residue data and a tolerance proposal

for residues of paraquat in/on taro foliage.

Additional data are required for soybean aspirated grain dust. 

The Agency has recently revised its policy on aspirated grain dust and

determined that it should be considered a RAC [see memo on

"Aspirated Grain Fractions (Grain Dust): A Tolerance Perspective", E.

Saito and E. Zager, 6/7/94]. The Agency also determined that a

tolerance for aspirated grain fractions for a pesticide should be

established based on the use of the pesticide on corn, wheat, sorghum,

and soybeans; paraquat is presently registered for use on these crops. A

soybean grain dust study has been submitted and was deemed

unacceptable because the data from the study could not be used reliably

to calculate the potential for concentration of paraquat residues in the

subject commodity. The Agency believes that based on paraquat

registered uses on soybeans, which include post-emergence directed

spray and use as a harvest aid, a potential exists for paraquat residues to

concentrate in/on soybean grain dust, and the registrant has committed

to conduct a new soybean aspirated grain dust study. 
43

No grain dust data are required for wheat and sorghum because

finite residues are not expected on the grain dust of these crops since

paraquat is registered for use only during the vegetative (and not the

reproductive) stages. With respect to corn, however, the Agency has

recently approved a SLN registration (TN940007) for use on corn as a

harvest aid (PHI of 7 days). To support this use, the Agency will

require additional field trials with corn as well as an aspirated grain

fraction study. 

GLN 171-4 (l): Magnitude of the Residue in Processed Food/Feed

The reregistration requirements for magnitude of the residue in

processed food/feed commodities are fulfilled for: apples; barley; cacao

beans; citrus; coffee; corn, field; cottonseed; figs; hops; mint; olives;

peanuts; pineapples; plums; potatoes; rice; safflower; sorghum;

soybeans; sugar beets; sugarcane; sunflower; tomatoes; and wheat. 

Data depicting the magnitude of the residue in the processed

commodities of grapes remain outstanding. The registrant must submit

data depicting the potential for concentration of paraquat residues in the

processed commodities of grapes bearing detectable weathered residues.

Residue data showed that residues concentrate in corn flour, soybean

hulls, pineapple processing residue, and sugarcane molasses. Tolerances

have been proposed accordingly for these commodities (see section IV,

Tolerance Summary Table). No processing data are required for

processed commodities of oats or rye since the registrant does not wish

to support the RAC tolerances for oat grain and there are presently no

registered uses of paraquat on rye grain. 

GLN 171-4 (j): Magnitude of the Residue in Meat, Milk, Poultry, and

Eggs

There are no registered direct animal treatments for paraquat on

cattle, goats, hogs, horses, sheep, or poultry. Based on acceptable

animal metabolism studies and magnitude of the residue in animal

studies, uses of paraquat are classified as Category (1) of 40 CFR

§180.6(a); finite residues will be incurred in foods from feed use of the

RAC including its byproducts. The residue of concern in eggs, milk,

and poultry and livestock tissues has been determined to be the parent,

paraquat; the current tolerance expression for animal commodities, as

defined in 40 CFR §180.205(a), is adequate.

Magnitude of the residue in milk, fat, meat, and meat byproducts

of ruminants: The maximum expected dietary intake of paraquat
44

residues by beef and dairy cattle was previously calculated to be

approximately 11 ppm. Based on tolerance reassessments of many

livestock feed items [including the forage and hay of non-grass animal

feeds (e.g., alfalfa) as well as grass forage], the new dietary burdens for

beef cattle and dairy cattle are recalculated to be 216 ppm and 252 ppm,

respectively.

The Agency has reevaluated the existing magnitude of the

residue data for milk and ruminant tissues and has determined that these

data are considered sufficient for reliable risk and tolerance

assessments: while the 170 ppm feeding rate represents only 0.7x the

maximum theoretical dietary burden, the Agency believes that a new

feeding study is not required since there do not appear to be significant

changes in tissue levels between 25 ppm and 170 ppm dosing levels. In

addition, the cows in the feeding study were dosed at 170 ppm (0.7x)

for 86-95 days. Since 170 ppm represents a concentration very close to

the concentration expected following immediate consumption of a

treated crop (i.e., a 0-day PHI), it is unlikely that a cow would consume

this dietary level for any extended period of time.

Based on the existing magnitude of the residue data for meat and

ruminant tissue, the Agency will recommend the following tolerances

for meat, fat, kidney and liver:

Muscle: 0.05 ppm

Fat: 0.05 ppm

Kidney: 0.5 ppm

Liver: 0.05 ppm

The Agency does not believe that detectable residues will result

in milk (normally considered a 180.6(a)(3) situation), but will

recommend retention of the present 0.01 ppm tolerance in the interest of

harmonization with the CODEX MRL of 0.01 ppm. 

Magnitude of the residue in eggs, fat, meat, and meat byproducts

of poultry: The maximum expected dietary intake of paraquat residues

by laying hens was previously calculated to be 1.4 ppm. Based on

tolerance reassessments of many poultry feed items, the new dietary

burden for poultry is calculated to be 1.1 ppm.

The Agency has reevaluated the existing magnitude of the

residue data in eggs and poultry tissues in conjunction with the

reassessments of tolerances for all poultry feed commodities. The
45

available poultry feeding data indicate that non-egg poultry

commodities are a 180.6(a)(3) situation and no tolerances need be

established. In the interest of harmonization with CODEX, the Agency

will recommend maintaining the current 0.01 ppm tolerance on eggs.

GLNs 165-1 and 165-2: Confined/Field Rotational Crops

An acceptable confined rotational crop study has been submitted. 

The study indicated that residues of paraquat do not accumulate in

rotated crops planted up to 120 days following treatment; therefore, no

plantback restrictions or field rotational crop studies are required.

c. Occupational and Residential

Handler Exposures & Assumptions

The Agency has determined that there is potential exposure to

mixers, loaders, applicators, and other handlers during usual usepatterns associated with paraquat dichloride. The Agency has identified

exposures to handlers during the agricultural and non-agricultural uses

of paraquat dichloride, including mixing and loading, and during

application by ground and aerial equipment, particularly backpack

applicators. Mixer/loader/applicator (M/L/A) exposure data for

paraquat dichloride were required in the December 1991 Data Call-In

(DCI) and in response to the Worker Protection Standard. These data

are discussed below. 

Based on the use patterns, several major occupational exposure

scenarios were identified for paraquat dichloride: (1) mixing/loading

liquid formulations for ground boom application; (2) mixing/loading

liquid formulations for aerial application; (3) applying as a spray with a

tractor-drawn ground boom; (4) applying as a spray with aerial

equipment; (5) mixing/loading liquid formulations for backpack

spraying; (6) applying as a spray with a backpack sprayer; (7) flagging

for aerial spray applications; (8) mixing, loading, and applying the

liquid formulation for spot treatment with a low pressure sprayer; (9)

mixing, loading, and applying the liquid formulation for spot treatment

with a backpack sprayer; and (10) mixing, loading, and applying the

liquid formulation for resin soaking uses with a low pressure sprayer.

The following chemical-specific mixer/loader/applicator study

was submitted by the registrant:
46

• MRID Number: 436442-02. 1995. D. Meier. Paraquat:

Worker Exposure During Mixing, Loading, and Application of

GRAMOXONE® EXTRA to Pecans Using Vehicle-Mounted

Ground Boom Equipment.

This worker biomonitoring study was performed to support label

revisions related to personal protective equipment required for mixers,

loaders, and applicators. Paraquat formulated as GRAMOXONE®

EXTRA herbicide in water was applied at a maximum application rate

of 0.94 lb cation/Acre by ground boom spray to pecan orchards in

southwestern Georgia and southeastern Alabama in September, 1994. 

Urinary excretion of paraquat was measured as the indicator of exposure

to workers mixing, loading, and applying the herbicide. A total of 17

combined mixer/loader/applicator replicates were monitored. The

Agency has reviewed this study and considers it acceptable since it

adequately meets Subdivision U Guidelines of the Pesticide Assessment

Guidelines.

Application of paraquat was conducted on fifteen separate pecan

farms using ground boom spray equipment mounted on open-cab

tractors. Three pints Gramoxone® EXTRA herbicide were mixed with

surfactant and water to 13 to 42 gallons/acre spray mixture. Workers

either poured the formulated product directly into the spray tank or

measured it into a calibrated container before transferring it to the spray

tank.

Although the study sponsor requested that the workers comply

with label requirements for personal protective equipment (PPE), they

did not interfere with the individual subject's typical practices. As a

result, a wide variety of PPE was employed. Of a total of 17

individuals, only eight wore gloves while mixing. The remaining nine

wore only normal work clothing. Three wore face/eye protection, and

wore an apron in addition to protective gloves. Two workers wore

Tyvek suits during application. The time spent mixing and loading

ranged from 14 to 104 minutes, and the total time of exposure from 230

to 660 minutes. Activities relevant to exposure were reported. The total

amount of paraquat handled varied from orchard to orchard, with a

range of 9.5 to 69 pounds of active ingredient.

The Limit of Quantification (LOQ) was stated to be 10 ng/ml for

a 1 ml urine sample. The level of detection was given as 5 ng/ml. The

study results showed that six of the 17 urine samples collected

contained detectable paraquat. All were in the Day 1 (application
47

exposure day) samples. Absorbed paraquat was estimated using a

referenced excretion rate of 59% from a paraquat pharmacokinetics

study in monkeys. The pharmacokinetics of paraquat have been

verified by the Agency. 

Of the six workers with detectable paraquat exposure, none wore

protective equipment while handling the formulation. There was no

discernable trend between the amount of pesticide handled and the

exposure incurred.

The available biomonitoring data for uses of paraquat are

summarized in Table A. These data originate from the groundboom

study (MRID 436442-02).

 

Total daily dose is calculated using the following formula:

Total Daily Dose (mg/kg/day) = 

Unit Dose (mg/kg/lb ai) X Appl Rate (lb cation/acre) X Acres Treated/Day

Margin of Exposure is calculated using the following equation:

MOE = NOEL ÷ Total Daily Dose
48

Table A. Short- and Intermediate-Term Risk From Paraquat, Derived From Biological Monitoring Data.

Exposure Scenario Unit Dose Equipment Clothing Scenario Monitored No. of Obs. Total Daily Dose Total MOE

(mg/kg/lb ai) Used (mg/kg/day)a

b

Mixer/Loader/Applicator Internal Dose

Ground boom 4.0 x 10 Open cab 9 reps no PPE worn; 4 reps gloves worn only when 17 3.2 x 10 9,400

(MRID 436442-02) tractor mixing; 2 reps gloves, face shield, and apron; 1 rep

[note: 1 lb cation/A and 80

Acres are assumed to calc. daily

dose; actual body weights of

subjects used to calc. unit dose.]

-6

respirator, face shield, goggles, apron, gloves, and

Tyvek for applying; 1 rep face shield, goggles,

apron, gloves, and Tyvek for applying

-4

Aerial 

[Note: 1 lb cation/A and 350, 800,

and 1200 acres are assumed to

calc. daily dose; the groundboom

unit dose is being used as a

surrogate for the aerial

applicators.]

4.0 x 10 Ground boom 9 reps no PPE worn; 4 reps gloves worn only when 17 350Acres: 1.4 x 10 350A: 2,100 -6

tractor mixing; 2 reps gloves, face shield, and apron; 1 rep

surrogate respirator, face shield, goggles, apron, gloves, and

Tyvek for applying; 1 rep face shield, goggles,

apron, gloves, and Tyvek for applying

-3

800Acres: 3.2 x 10 800A: 940 -3

1200Acres: 4.8 x 10 1200A: 630 -3

Total Daily Dose (mg/kg/day) = Unit Dose (mg/kg/lb cation) X appl rate (lb cation/A) X acres per day. a

MOE = NOEL / Total Daily Dose (mg/kg/day). Where: NOEL = 3 mg/kg/day. b
49

PHED V1.1 data are used to estimate short- and intermediateterm exposure, dose, and risk from paraquat for backpack sprayer

mixer/loaders and applicators, for flaggers for aerial spray applications,

for mixers/loaders/applicators for spot treatments using a backpack

sprayer or low pressure wand, and for mixers/loaders/applicators for

resin soaking uses using a low pressure wand. These exposure

scenarios are presented in Tables B and C. Inhalation exposure and

doses were not calculated since spray particles used in applying

paraquat are well beyond the respirable range and paraquat has a very

low vapor pressure. The potential daily dermal dose is calculated using

the following formula:

Potential Daily Dermal Dose (mg/kg/day) =

Dermal Unit Exposure (mg/lb ai) X max. Appl. Rate (lb cation/amount) X max. area

treated (amount/day) X Dermal Absorption ÷ Body Weight (kg)

These calculations of daily dose of paraquat received by handlers

are used to assess the risk to those handlers. The dermal Short-Term

and Intermediate-Term MOE was calculated using the following

formula:

Dermal MOE = NOEL (mg/kg/day) ÷ Potential Daily Dermal Dose (mg/kg/day)
50

Table B. Short-Term and Intermediate-Term Exposure and Risk to Paraquat Dichloride Derived From PHED V1.1 Data.

Exposure Scenario Baseline Dermal Maximum Label Daily Maximum Area Potential Daily Dermal Risk Mitigation

(#) Unit Exposure Application Rate Treated Dermal Dose MOE a

(mg/lb cation) (mg/kg/day)

b c d e

f

[Dermal Unit Exposure] Dermal 

[(mg/lb cation)] MOE

Potential Daily Dermal

Dose (mg/kg/day) d

e

Mixer/Loader

Mixing/loading liquids for backpack sprayer 2.9 1 lb cation/A 20 acres 0.0029 1000 NA NA

application (5)

g

Applicator

Backpack Sprayer (6) 483 1 lb cation/A 4 acres 0.097 31 [234] 64

*0.625 lb cat/A *100

g

0.0468

Flagger

Flagging (liquids) (7) 0.01 1 lb cation/A 350 to 1,200 0.00018 to 0.0006 17,000 to NA NA

5,000

Mixer/Loader/Applicator

Low Pressure Hand-held Sprayer (Spot 104 0.0195 lb cation/gal 40 gals 0.0041 730 NA NA

Treatment) (8)

Backpack Sprayer (Spot Treatment) (9) 486 0.0195 lb cation/gal 40 gals 0.019 160 NA NA

Low Pressure Sprayer (Resin Soaking) (10) 104 0.4 lb cation/gal 40 gals 0.083 36 [4.1] 910

0.0033

a Long pants, long-sleeved shirt, no gloves. Mixer/loader assessments are from using open mixing systems.

b Label Reg No. 10182-103, 10182-111, 10182-120.

c Values represent the maximum area or the maximum volume of spray solution which can be used in a single day to complete treatments for each exposure scenario of concern.

d Potential daily dermal dose (mg/kg/day) = Dermal Unit Exposure (mg/lb cation) X 0.003 (0.3 percent dermal absorption) X Maximum Application Rate (lb cation/acre or lb cation/gal) X Maximum

Treated (acres/day or gal/day) ÷ 60 kg BW.

e Dermal MOE = NOEL/Potential daily dermal dose (mg/kg/day) (short- and intermediate-term NOEL = 3 mg/kg/day) 

f Addition of gloves to long pants & long-sleeved shirt.

g If 40 gal/day can be applied by a backpack sprayer, then 4 acres will be treated at a finish spray volume of 10 gal/A

* See Tina Manville’s memo/response - An application rate of 0.625 lb cation/Acre is acceptable and will provide MOE’s of 100 for backpack application.
51

Table C. Exposure Scenario Descriptions of Baseline and Risk Mitigation Measures for Uses of Paraquat Dichloride from PHED Data.

Exposure Scenario Data Source Additional PPE Standard Assumptions (8- Comments

(#) hr work day)

a b

Mixer/Loader Exposure

Mixing/loading PHED V1.1 NA 200 gallons (for 20 acres) Baseline : Dermal acceptable grades & 25 to 122 replicates; High confidence

liquids for backpack (including mixer/loader supporting data.

sprayer application PHED study # five backpack sprayers

(5) 9003)

c

PHED data used for baseline; no PF necessary.

Applicator Exposure

Backpack Sprayer (6) PHED V1.1 gloves 4 acres at a finish spray Baseline and Additional PPE: Dermal acceptable grades & 60 to 69 replicates; 

(including volume of 10 gal/acre High confidence data.

PHED study # (therefore 40 gals/day)

9003) Baseline exposures were calculated from total deposition using a 50% PF for the

addition of a single layer of clothing (feet data were deleted). Additional PPE

exposure was calculated by adding a 90% PF for the addition of gloves to the

baseline exposure.

Flagger

Flagging PHED NA 350 to 1,200 acres Baseline: Dermal grades acceptable & 16 to 18 replicates; High confidence data.

(liquids) (7) V1.1

PHED data used for baseline; no PF necessary.

Mixer/loader/applicator Exposure

Low Pressure Hand- PHED NA 40 gals total using two to Baseline: Dermal all grades & 25 to 96 replicates; Low confidence data.

held Sprayer- Spot V1.1 three gallon hand held

Treatment (8) wand sprayers

PHED data used for baseline; no PF necessary. 

Backpack Sprayer - PHED V1.1 NA 40 gals Baseline: Dermal acceptable grades & 60 to 69 replicates; High confidence data.

Spot Treatment (9) (liquid m/l unit

exposure + Baseline exposures were calculated from total deposition using a 50% PF for the

backpack appl. addition of a single layer of clothing (feet data were deleted). 

unit exposure

[2.9 + 483

mg/lb cation])
Exposure Scenario Data Source Additional PPE Standard Assumptions (8- Comments

(#) hr work day)

a b

52

Low Pressure Sprayer PHED V1.1 gloves 40 gals total using two to Baseline and Additional PPE: Dermal all grades & 15 to 96 replicates; Low

(Resin Soaking) (10) three gallon hand held confidence data. 

wand sprayers

PHED data used for baseline and additional PPE; no PF necessary. 

Standard Assumptions based on an 8-hour work day as estimated by OREB. BEAD data were not available. a

"Acceptable grades," as defined by OREB SOP for meeting Subdivision U Guidelines, are grades A and B. All grades that do not meet OREB's SOP are listed individually. b

Baseline is defined as long pants, long-sleeved shirt and no gloves c
53

Post-Application Exposures & Assumptions

The Agency has determined that there is potential exposure to

persons entering treated sites following: (1) preemergent/early-season

treatments, particularly in crop areas; (2) directed spray treatments,

particularly in orchard or vegetable-crop sites with heavy weed density; 

and, (3) desiccant/harvest-aid treatments particularly when performing

harvesting-related tasks, such as removal or compacting (i.e. trampling)

of desiccated foliage and stems on crops such as cotton, dry beans,

potatoes, sunflowers, and sugar cane.

Post-application exposure data were required in the December

1991 DCI and in response to the Worker Protection Standard.

The following post-application study was submitted by the

registrant:

• MRID Number - 436182-02. Tak Iwata and Malcolm Findlay,

1994. Worker Exposure During Re-Entry into Paraquat-Treated

Cotton Fields: Biological Monitoring in Georgia in 1994.

This worker biomonitoring study measured urinary excretion of

paraquat as a indicator of exposure to workers reentering the treated

fields for the purpose of scouting. Cotton fields were treated with

STARFIRE, a product normally used by growers as a harvest aid, at a

rate of 0.55 lb cation/A. Scouting activities started at 4 hours (12

replicates) and 24-hours (13 replicates) post-application. Scouting

activities consisted of walking into the field, handling and cracking a

few bolls, and bending foliage and stems for a total field exposure of 2.5

hours. Complete 24 hour urine samples were collected from each

subject on the reentry exposure day and on the next 5 days.

The study results showed that only one urine sample contained

detectable paraquat. This was from a Day 1 (reentry exposure day)

urine sample from a subject in the 4 hour reentry test group. Based on a

reported urinary level of 6 mg/ml and a sample volume of 400 ml, a

total amount of paraquat excreted was estimated as 0.0024 mg. An

exposure of 0.00004 mg/kg/day was calculated for this subject using a

204 pound body weight and a referenced excretion rate of 59% from a

paraquat pharmacokinetics study in monkeys (see MRID No. 436182-

01). All other (non-detect) data points were treated as containing no (0)

paraquat.
54

The authors also present an exposure assessment in a separate

submission (MRID No. 436182-01) which contains an estimate of a

Margins of Exposure (MOE). Using a NOEL value of 0.6 mg/kg for a

90 day feeding study in dogs (from the 1987 Registration Standard,

which identifies this level as 0.5 mg/kg/day), a MOE of 15,000 was

derived. Based on this value and the stated "worst case" conditions of

the study, the authors suggest that workers could safely reenter

paraquat-treated fields (cotton as well as other crops) 4 hours after

application (when sprays have dried). 

The Agency has confirmed the pharmacokinetic data used in this

study. A single dose of paraquat dichloride administered

subcutaneously to rats was excreted mostly in urine (73-96%) as

unchanged paraquat within 24 hours after dosing. Therefore adequate

time was allowed in this experiment for urine collection.

The Agency considers this study acceptable since the EPAapproved protocol was followed. After the protocol was approved, the

Agency exempted certified or licensed crop advisors and their

employees from the Worker Protection Standard requirements, except

for obtaining pesticide safety training, based partially on the assumption

that such activities result in low exposures (FR, Vol. 60, No. 85,

5/3/95). In addition, the 2.5 hour duration of exposure may suggest that

this study was not in fact a worst-case scenario relative to other crops

and cultural practices. Therefore, the Agency is requiring reentry

intervals longer than 4 hours which had been previously suggested (see

Risk from Post-Application Exposures for specific Agency

requirements).

3. Risk Assessment

a. Dietary

Residues

Tolerances for paraquat residues in/on raw agricultural and

animal commodities are published in 40 CFR §180.205(a) and (b), in

processed food in 185.4700, and in feed at 186.4700. The available

data support the established tolerances on all but sorghum forage,

ruminant kidney, oats, rye, soybeans and hops. Thus, for the purposes

of this analysis, the tolerances for sorghum forage was reassessed from

0.05ppm to the higher value of 0.1 ppm, while kidney was reassessed
55

from 0.3 ppm to 0.5 ppm, soybeans from 0.05 ppm to 0.25 ppm, and

hops from 0.2 ppm to 0.5 ppm.

Chronic Dietary Exposure

A DRES (Dietary Risk Evaluation System) chronic exposure

analysis was performed using tolerance level residues and percent crop

treated to estimate the Anticipated Residue Concentration (ARC) for the

general population and 22 population subgroups. Even with rye, oats,

and poultry commodities included, the Reference Dose (RfD) was not

exceeded for any of the 22 population subgroups analyzed.

 As there are presently no registered uses of paraquat on rye, it is

recommended that tolerances for this commodity be revoked. It is also

recommended to revoke the tolerance on oats, as the registrant has

indicated that they do not wish to support this use. Additionally, it is

recommended that tolerances for poultry (except for eggs) be revoked. 

Further, a tolerance for popcorn (0.05 ppm) was included in this

analysis and should be proposed (See Section IV, Tolerance

Reassessment Summary and Table). 

Chronic Dietary Exposure Using Tolerances

Existing tolerances result in a Theoretical Maximum Residue

Contribution (TMRC) which represents 10% of the RfD for the U.S.

general population. The highest subgroup, non-nursing infants (<1 year

old) occupies 31% of the RfD. 

Dietary Risk to Paraquat

Subgroup Exposure (mg/kg/day) %RfD

U.S. Population 0.000442 10

Non-Nursing Infants (<1 year old) 0.001398 31

Children (1-6 years old) 0.001070 24

b. Occupational and Residential

Risk From Handler Exposures

Based on biological monitoring data, the margins of exposure

(MOEs) are acceptable (greater than 100) for: (1) mixing/loading to

support ground applications; (2) mixing/loading to support aerial
56

applications; (3) applying using ground boom equipment; and (4)

applying using aerial equipment (ground boom data were used as a

surrogate for aerial). Surrogate exposure data from PHED indicate that: 

(1) mixing/loading liquid formulations to support several applicators

using backpack sprayers; (2) flagging; (3) mixing/loading/applying for

spot treatments using low-pressure sprayers or backpack sprayers are

acceptable; and (4) with the addition of gloves mixing/loading/applying

for resin soaking uses using low-pressure sprayers (MOEs greater than

100).

Based on exposure data from PHED, the MOE for backpack

applicators (non-spot treatment) is unacceptable (MOE less than 100)

when applicators are wearing long pants and long sleeved-shirt, and

chemical-resistant gloves. The Agency is concerned about the

practicality of adding another layer of PPE (woven material), due

primarily to heat stress considerations and the "wicking" affect of

multiple layers. As a risk mitigation measure, all paraquat labels could

be modified to specify that backpack applications for spot treaments be

made at application rates no higher than 0.0195 lb cation/gal (or 0.23%

cation wt/wt spray solutions).

Risk From Post-Application Exposures

Based on the postapplication biological monitoring study The

Agency has determined that a 12-hour restricted-entry interval is

adequate for the uses of paraquat for preemergent or early-season weed

control. In these use-situations, the paraquat is directed at the soil and

weeds (if present) that are generally less than six inches tall and the

workers' degree and duration of contact with treated surfaces is likely to

be similar to or less than that for the scouts in the biological monitoring

study. 

Based on the postapplication biological monitoring study, The

Agency also has determined that a 12-hour restricted-entry interval is

adequate for the uses of paraquat for weed control in orchard and

vegetable crops where the spray is directed solely at the weeds (not

broadcast over the entire crop area). In these directed-spray usesituations where the paraquat is directed at the weeds, entering workers'

degree and duration of contact with treated surfaces are likely to be

similar to or less than that for the scouts in the biological monitoring

study. 
57

For desiccation and harvest aid applications of paraquat, The

Agency is establishing a 24-hour restricted-entry interval (REI). The

Agency believes that such uses may result in exposures to workers of

greater degree and duration than that for the scouts in the biological

monitoring study, particularly when the workers are performing

harvesting-related tasks, such as removal or compacting (i.e. trampling)

of desiccated foliage and stems on crops such as cotton, dry beans,

potatoes, sunflowers, and sugar cane. It is well documented that

paraquat is rendered biologically inactive upon contact with the soil. 

However less is known about its residues on leaves. After 21 days, 66%

of paraquat is lost from plant surfaces. The Agency does not have any

foliar dissipation curves for paraquat to better quantify post-applicator

exposure. Personal protective equipment is required for workers who

enter the treated area before the REI has expired.

The 12 and 24-hour post-application entry restrictions for

paraquat dichloride do not apply to uses outside the scope of the Worker

Protection Standard (WPS) for Agricultural Chemicals. The predicted

frequency, duration, and degree of exposure by such uses do not

warrant the same risk mitigation measures required for users covered by

the WPS who are engaged in agriculture for commercial or research

purposes. However, the Agency is concerned about exposures

immediately following applications while the sprays are still wet.

Additional Occupational/Residential Exposure Studies Handler

Studies

None are necessary.

Post-Application Studies

If the registrant believes that a restricted-entry interval of less

than 24 hours is appropriate for the desiccation/harvest-aid uses of

paraquat, an additional study is required. Requirements for postapplication exposure studies are addressed by Subdivision K of the

Pesticide Assessment Guidelines. The required data include: Guideline

132-1(a): Foliar Residue Dissipation.

4. Food Quality Protection Act Considerations

The Food Quality Protection Act of 1996 (FQPA) amended the FFDCA

by setting a new safety standard for the establishment of tolerances. In

determining whether a tolerance meets the new safety standard, section
58

408(b)(2)(C) directs EPA to consider information concerning the susceptibility

of infants and children to pesticide residues in food, and available information

concerning aggregate exposure to infants and children of such residues, as well

as the potential for cumulative effects from pesticide residues and other

substances that have a common mechanism of toxicity. 

The FQPA amendments to section 408(b)(2)(C) also direct the Agency,

in the case of threshold effects, to add an additional 10-fold margin of safety

for the protection of infants and children unless the Agency concludes, based

upon reliable data, that a different safety margin will be safe for infants and

children. 

Section 408(b)(2)(D) establishes factors that the Agency must consider

in determining whether the safety standard is met in deciding to issue or

reassess tolerances. These factors include the consideration of available

information on the aggregate exposures to the pesticide from dietary sources

including drinking water as well as non-occupational exposures such as those

derived from pesticides used in and around the home. The Agency must also

consider available information concerning the potential cumulative effects of

the pesticide for which a tolerance is being sought as well as other substances

that have a common mechanism of toxicity for the general population and

major subgroups of the population.

Because paraquat has food uses, specific consideration of the risks to

infants and children, as well as aggregate exposures and potential cumulative

effects is warranted.

 

a. Potential Risks to Infants and Children

In determining whether a safety factor different than the

additional 10-fold factor is or is not appropriate for assessing risks to

infants and children, EPA considers all reliable data and makes a

decision using a weight of evidence approach taking into account the

completeness and adequacy of the toxicity data base, the nature of the

effects observed in pre and post-natal studies, and other information

such as epidemiological data.

For the purpose of assessing the pre- and post-natal toxicity of

paraquat, EPA has evaluated four developmental (of which two were

used to evaluate developmental and maternal toxicity) and one

reproduction study. Based on current data requirements, these three

studies constitute a complete data base for evaluating pre and post natal

effects for food use chemicals when considered along with other
59

required toxicity studies. However, as EPA fully implements the

requirements of FQPA, additional data related to the special sensitivity

of young organisms may be required. 

Developmental and Reproductive Effects

The effects observed in the paraquat developmental and

reproduction studies can be summarized as follows:

Four developmental/maternal toxicity studies were evaluated for

paraquat. The following two were used to assess the

developmental/maternal toxicity of paraquat. In the first of the two

studies, no developmental effects were found, and the developmental

NOEL was set at 8 mg/kg/day (HDT), and the maternal NOEL at 8

mg/kg/day (HDT). 

In the second of the two studies, maternal toxicity was reported

at the two highest doses and included clinical signs, decreased body

weight gain, deaths of 6 high dose animals versus none in the control

group, respiratory distress in 3 high-dose females, histopathological

findings in the lungs and kidneys of the nonsurvivors. Developmental

effects (delayed ossification in the forelimb and hindlimb digits) were

observed only in the mid-dose and high-dose groups. Based on these

findings, the NOEL and LOEL for maternal toxicity are 1 mg/kg/day

and 5 mg/kg/day, respectively, expressed as paraquat cation. The

NOEL and LOEL for developmental toxicity are also 1 mg/kg/day and 5

mg/kg/day, respectively. 

The overall maternal and developmental NOEL for the rat is 3

mg/kg/day (paraquat cation) based on a weight-of-evidence of the

results from two developmental studies in the rat.

In a reproductive study in rats, the NOEL and LOEL for

systemic toxicity are 1.25 mg/kg/day and 3.75 mg/kg/day, respectively. 

The NOEL for reproductive toxicity is 7.5 mg/kg/day (HDT), based

on severe lung damage caused by paraquat (red or purple discoloration,

congestion, edema, fibrosis, hyaline membrane formation, inflammatory

cell infiltration and/or hyperplasia) and incidence of alveolar

histiocytosis. Paraquat, at all levels tested, had no effect on body weight

gain, food consumption and utilization, fertility and length of gestation. 

The developmental data for paraquat indicate developmental

effects occurred at doses that were the same as or higher than doses
60

which cause maternal toxicity. The Agency would generally be

concerned when developmental/reproductive effects are seen at doses

lower than those which cause maternal effects. The developmental

studies in conjunction with the reproduction study do not indicate any

additional sensitivity of young organisms to paraquat. Based on current

toxicological data requirements, the data base, relative to pre- and postnatal toxicity, is complete.

Uncertainty Factor

Based on reliable data as outlined above, the Agency concludes

that an additional uncertainty factor is not warranted for the paraquat

chronic risk assessment, nor is the use of an additional uncertainty

factor indicated for estimating risk from acute exposures detailed below.

b. Aggregate Exposure/Risk

In examining aggregate exposure, FQPA directs EPA to take

into account available information concerning exposures from the

pesticide residue in food and all other exposures for which there is

reliable information. These other sources of exposure include drinking

water, and non-occupational exposures, e.g., to pesticides used in and

around the home. For estimating acute and chronic risks the Agency

considers aggregate exposures form the diet and from drinking water. 

Exposures from uses in and around the home that may be of short term,

intermediate or other duration may also be aggregated as appropriate for

specific chemicals.

Paraquat has no residential or other non-occupational uses that

might result in exposure to children. In addition, paraquat is not

expected to be a contaminant of groundwater. Paraquat dichloride binds

strongly to soil clay particles and it did not leach from the surface in

terrestrial field dissipation studies. There were, however, detections of

paraquat in drinking water wells from two states cited in the Pesticides

in Ground Water Database(1991). These detections are not considered

to be representative of normal paraquat use. Therefore, paraquat is not

expected to be a groundwater contaminant or concern based on normal

use patterns.

Due to its persistent nature, paraquat could potentially be found

in surface water systems associated with soil particles carried by

erosion, however, paraquat is immobile in most soils, and at very high

application rates (50-1000X), there was no desorption of paraquat from
61

soils. Therefore, based on paraquat’s normal use patterns and unique

environmental fate characteristics, exposures to paraquat in drinking

water are not expected to be obtained from surface water sources .

Thus, the only exposures considered in acute and chronic risk

assessments are dietary.

Acute Risk

No data are available that suggest an acute dietary endpoint of

concern, therefore an acute dietary risk assessment was not required for

paraquat. 

Chronic Risk

Dietary Exposure

A chronic dietary exposure analysis was performed using

tolerance-level residues and percent crop treated information for some

crops resulting in an ARC (Anticipated Residue Concentration) of 10%

of the RfD for the US population, 24 and 31% of the RfD for children

(ages 1-6) and non-nursing infants (<1 yr), respectively.

Tolerances have been established in/on over 80 crops. The

available data support the established tolerances listed in 40 CFR

section 180.205 (a) and (b) in processed food in 185.4700, and in feed

at 186.4700 on all but sugar beet tops, ruminant kidney, oats, rye,

soybeans and hops which need to be amended.

Conclusion Regarding Chronic Aggregate Exposure to Paraquat

The Agency concludes that the aggregate risks to the general

U.S. population, and to the population subgroup of infants and children,

resulting from paraquat uses are not of concern.

c. Cumulative Effects

In assessing the potential risk from cumulative effects of

paraquat and other chemical substances, the Agency has considered

structural similarities that exist between paraquat and other bipyridylium

compounds such as diquat dibromide. Examination of the toxicology

databases of paraquat and diquat dibromide, indicates that the two

compounds have clearly different target organs. At doses at which
62

paraquat is a highly specific pulmonary toxicant in rats and dogs, diquat

produces cataracts and no significant pulmonary toxicity in the same

species. Although both chemicals presumably can induce tissue

damage via the generation of oxygen free radicals, the two compounds

differ in their tissue distribution pattern. Unlike paraquat, diquat shows

no special affinity for the lung and appears to be taken up by the

transport mechanism that selectively concentrates paraquat in the lung. 

Paraquat is accumulated in the lungs and is thus a lung toxicant,

whereas diquat is not accumulated in the lungs and is not a lung

toxicant. 

Although paraquat also produced a dose-related incidence of

cataracts in Fisher 344 rats after 103 weeks, a dose-related incidence of

cataracts was not seen in chronic studies with Wistar rats, beagle dogs

or JCL-ICR mice. Thus, paraquat appears to be a weaker cataractogenic

agent when compared to diquat. 

Based on the available data, the Agency does not believe that the

toxic effects produced by paraquat would be cumulative with those of

diquat dibromide.

C. Environmental Assessment

The environmental fate and ecological toxicity data bases are complete. 

Paraquat dichloride poses a risk to nonendangered and endangered non-target

terrestrial and aquatic plants. Acute risk to terrestrial organisms only exists

immediately after application. Although a chronic risk to birds is not expected as a

result of residues on dietary food items, the Agency is concerned that direct

application of paraquat dichloride to eggs may affect avian reproduction. 

1. Ecological Toxicity Data 

Sufficient ecological toxicity data exist to assess the risk of paraquat

dichloride to non-target wildlife. 

a. Toxicity to Terrestrial Animals

(1) Birds, Acute and Subacute

In order to establish the toxicity of paraquat dichloride to

birds, the following tests are required using the technical grade

material: one avian single-dose oral (LD ) study on one species 50

(preferably mallard or bobwhite quail); two subacute dietary
63

studies (LC50) on one species of waterfowl (preferably the

mallard duck) and one species of upland game bird (preferably

bobwhite quail). The following two tables summarize the avian

acute oral toxicity findings and the avian subacute dietary

toxicity findings. 

Avian Acute Oral Toxicity Findings 

Species % A.I. LD50 mg/kg MRID No. Toxicity Fulfills 1

(cation Author/Year Category Guideline

equivalent) Requiremen

t

Northern 93.3 176 (128.1) 00029001 Moderately Yes 

Bobwhite (Fink, et toxic

al/1979)

Mallard 21 199 (144.8) 00160000 Moderately Partial

(Hudson, et toxic

al/1984)

LD values given are in terms of technical paraquat dichloride not in terms of the cation 1

50

Avian Subacute Dietary Toxicity Findings

Species % A.I. LC ppm MRID No. Toxicity Fulfills 50

(cation Author/Year Category Guideline

equivalent) Requiremen

t

Northern 29.1 981 (714) 00022923 Moderately Yes

Bobwhite Hill et al/1975 toxic

Ring-neck 29.1 1468 (1068.5) 00022923 Slightly toxic Yes

Hill et al/1975

Mallard 29.1 4048 (2946.3) 00022923 Slightly toxic Yes

Hill et al/1975

The 29.1% test material is an end use product (paraquat dichloride CL) which contains 21.0% cation. The EP is prepared by diluting 1

the TGAI (paraquat dichloride concentrate, 43% cation) with water.

LC values given are in terms of technical paraquat dichloride not in terms of the cation 2

50

These results indicate that paraquat dichloride is

moderately toxic to avian species on an acute oral and subacute

dietary basis. The guideline requirements are fulfilled. (MRIDs

00029001, 00022923, 00016000)
64

(2) Birds, Chronic

Avian reproduction studies are required when

birds may be exposed repeatedly or continuously through

persistence, bioaccumulation, or multiple applications, or

if mammalian reproduction tests indicate reproductive

hazard. Present product labeling for use of paraquat

dichloride on a variety of crops allows several

applications of the end-use product per growing season. 

The following table summarizes the avian reproduction

findings. 

Avian Reproduction Findings1

Species % A.I. NOEC LOEC Endpoints MRID No. Fulfills 2

ppm ppm affected Author Guide-

/Year line

Requir

e-ment

Northern 31.5 100 215 mortality 00110453 yes 

Bobwhite Fink et

al./1981

Northern 31.5 100 >100 no effects 00110454 partial

Bobwhite (highest Fink et

level al./1982

tested)

Mallard 31.5 30 100 % viable 00110455 yes

Duck eggs, eggs Fink et

set, al./1982

normality of

hatchlings

and number

of 14-day

old survival

NOEC and LOEC values given in terms of the cation not the technical paraquat dichloride.

1

 %a.i. reflects % cation by weight.

2

Additional data showed that significant mortality and reduced growth resulted

when mallard eggs were treated at 0.5 and 5.0 lb cation/A. (MRID 00162746)

The avian reproductive studies indicate that paraquat dichloride can affect

reproduction or hatchability in birds when adult birds are exposed to more than 30

ppm of paraquat or when eggs are treated at 0.5 and 5.0 lb ai./A. The guideline

requirements are fulfilled. (MRIDs 00110453, 00110454, 00110455, and 00162746)
65

(3) Mammals

Wild mammal testing is required on a case-by-case basis, depending on the

results of the lower tier studies such as acute and subacute testing, intended use

pattern, and pertinent environmental fate characteristics. In most cases, however, an

acute oral LD50 is used to determine toxicity to mammals. This LD50 is reported

below.

Mammalian Acute Oral Toxicity Findings

Species LD50 mg/kg MRID # Toxicity Category 1

(cation equivalent)

 Rat (small 344 (male) (250) 43685001 moderately toxic

mammal surrogate) 283 (female) (206)

 LD values given are in terms of technical paraquat dichloride not in terms of the cation. 1

50

The available mammalian data indicate that paraquat dichloride is moderately

toxic to small mammals on an acute oral basis. (MRID 43685001)

The table below shows the chronic toxicity of paraquat dichloride to

mammals.

Chronic Toxicity to Mammals

Test Organism Type of Study Duration Chronic Effects NOEL MRID #

of Study (ppm)

1

Fisher 344 Rats Feeding/Carcinogenicity 113-124 Eye 25 0013863

wks Opacity/Cataracts 7

Wistar Rats Feeding/Carcinogenicity 104 wks Opacity/Cataracts 100 4021800

1

Wistar-Derived Reproductive Toxicity 11-12 wks Lung Damage and 25 0012678

Alderley Park Mortality 3

Strain

 NOEL data given in terms of cation.

1

The available mammalian chronic data indicate paraquat

is lethal to some small mammals at levels below 25 ppm after 12

weeks of exposure. 
66

Additional data showed that exposure of rabbits to freshly

sprayed foliage can produce toxic symptoms and death. The

LD is 110 mg/kg for rabbit and 35 mg/kg for Belgian hare. 50

Also, the residues of paraquat measured in vegetation coupled

with evidence of pulmonary and lingual lesions demonstrate the

sensitivity of the hare to paraquat. (MRID 00162747, MRID

00162741)

(4) Insects

A honey bee acute contact LD50 study is required if the

proposed use will result in honey bee exposure. The available

insect acute contact toxicity findings are summarized in the

following table. 

Nontarget Insect Acute Contact Toxicity Findings

Species % AI LD50 g a.i./bee MRID No. Toxicity Fulfills 1

Author/Year Category Guideline

Requirement

Honey 99% Tech. and Contact LD 43942603 practically yes

Bee 1.67 lb/gal SC >144 ug ai/bee Bull and nontoxic

(Gramoxone) (tech) Wilkinson/1977

50

= 72 ug ai/bee

(Gramoxone)

Oral LD50

51 ug ai/bee

(tech)

31 ug ai/bee

(Gramoxone)

Honey Technical 2.74% mortality 00028772 relatively yes

Bee at 6.04 g/bee Atkins et non-toxic

al./1973

Honey Technical contact LD > 05001991 relatively yes

Bee 48 g/bee Stevenson/ non-toxic

50

1978

Honey 4 lb ai./A spray 55% mortality 00111488 N/A supplemental

Bee after 2 days and Moffett et

90% after 3 al./1972

days. (LD Not 50

obtained)

Toxicity data are given in terms of technical paraquat dichloride not the cation. 1

There is sufficient information to characterize technical

paraquat dichloride and a formulated product as relatively nontoxic to bees. The guideline requirement is fulfilled. (MRID#s
67

00028772, 05001991, 00111488, 43942603). An additional

study showed that bees exposed to direct application of paraquat

dichloride CL at 4 lbs cation/A caused 55% mortality within 2

days exposure and 99% mortality after 3 days exposure (MRID

00111488). This study was performed with an end-use product

of Paraquat dichloride and a surfactant. It is possible that the

surfactant caused paraquat to be more easily absorbed by the

honey bees resulting in the observed mortality.

b. Toxicity to Aquatic Animals

(1) Freshwater Fish

In order to establish the toxicity of a pesticide to

freshwater fish, the minimum data required on the technical

grade of the active ingredient are two freshwater fish toxicity

studies. One study should use a coldwater species (preferably

the rainbow trout), and the other should use a warmwater species

(preferably the bluegill sunfish). The 96-hour freshwater fish

acute toxicity findings for the technical grade of the active

ingredient are summarized in the following table.

Freshwater Fish Acute Toxicity Findings

Species % A.I. LC50 ppm a.i. MRID No. Toxicity Fulfills 1

Author/year Category Guideline

Requirement

Rainbow 24% liquid 15 40098001 slightly yes

trout 2 lb. cation/gal Mayer, F.L. and toxic

concentrate M.R.

Ellersieck/1986

Bluegill 24% liquid 13 40098001 slightly yes

sunfish 2 lb. cation/gal Mayer, F.L. and toxic

concentrate M.R.

Ellersieck/1986

Rainbow 29.1 (cation) 38.68 00162736 slightly yes

Trout Palmateer/1980 toxic

Bluegill 29.1 (cation) 156 00162737 practically yes

sunfish Palmateer/1979 non-toxic

Rainbow 29.1 29 00162738 slightly yes

Trout McCann, toxic

J./1977

LC values given are in terms of the cation not the technical paraquat dichloride. 1

50
68

The results of the 96-hour acute toxicity studies indicate

that paraquat dichloride is slightly toxic to fish. The guideline

requirements are fulfilled. (MRID 40098001, 00162736,

00162737, 00162738)

Data from fish early life-stage tests or life-cycle tests are

required if the product is applied directly to water or expected to

be transported to water from the intended use site, and when the

pesticide is intended for use such that its presence in water is

likely to be continuous or recurrent regardless of toxicity; or if

any acute LC or EC is less than 1 mg/L; or if the EEC in water 50 50

is equal to or greater than 0.01 of any acute EC or LC value; 50 50

or if the actual or estimated environmental concentration in water

resulting from use is less than 0.01 of any acute EC50 or LC50

value and any of the following conditions exist: studies of other

organisms indicate the reproductive physiology of fish and/or

invertebrates may be affected; or physicochemical properties

indicate cumulative effects; or the pesticide is persistent in water

(e.g. half-life greater than 4 days).

Chronic fish studies are not required at this time because

paraquat dichloride is not registered for aquatic uses, is tightly

bound to soil, is not likely to be transported to aquatic

environments in significant quantities from runoff or drift and is

only slightly toxic to fish species. 

(2) Freshwater Invertebrates

The minimum testing required to assess the hazard of a

pesticide to freshwater invertebrates is a freshwater aquatic

invertebrate toxicity test, preferably using first instar Daphnia

magna or early instar amphipods, stoneflies, mayflies, or midges. 

The freshwater invertebrate toxicity findings are summarized in

the following table.
69

Freshwater Invertebrate Toxicity Findings

Species % A.I. EC50 MRID NO. Toxicity Fulfills 1

(ppm ai) Author/Year Category Guideline

Requirement

Daphnia

pulex

24% liquid 4.0 40098001 Moderately Yes

2 lb. Mayer, F.L. and toxic

cation/gal M.R.

concentrate Ellersieck/1986

Daphnia

magna

92.3 1.2 00114473 Moderately Yes

Wheeler/1978 toxic

Daphnia

magna

29.1 8.0 GS0262-028 Moderately Yes

Thompkins/1979 toxic

 LC values given are in terms of the cation not the technical paraquat dichloride. 1

50

There is sufficient information to characterize paraquat

dichloride as moderately toxic to aquatic invertebrates. The

guideline requirement is fulfilled. (MRID 40098001, 00114473,

GS0262-028)

(3) Estuarine and Marine Animals

Acute toxicity testing with estuarine and marine

organisms is required when an end-use product is intended for

direct application to the marine/estuarine environment or is

expected to reach this environment in significant concentrations. 

Paraquat dichloride is not registered for aquatic use and is not

expected to reach the marine/estuarine environment in

significant concentration. Therefore, marine/estuarine studies

are not required at this time.

c. Toxicity to Plants

(1) Terrestrial

Currently, terrestrial plant testing (seedling emergence

and vegetative vigor) is required for herbicides which have

terrestrial non-residential outdoor use patterns and appear to

move off site of application through volatilization (vapor

pressure >1.0 x 10 mmHg at 25 C) or drift (aerial or irrigation); -5 o

and/or which may have endangered or threatened plant species

associated with the site of application. Paraquat has a low vapor

pressure and extremely high adsorption coefficients such that it
70

would not be expected to volatilize once applied to the soil. 

However, some of the use patterns for paraquat dichloride may

allow off site movement as a result of drift from either ground or

aerial application, terrestrial plant testing is required.

Tier 2 Toxicity data on the TEP material for the most

sensitive species are summarized in the following table.

Nontarget Terrestrial Plant Toxicity Findings 

Species % Seedling emergence Vegetative vigor

A.I.1 EC25

2

 (lbs cation/A) EC25

2

(lbs cation/A)

Dicot- (Cocklebur) 29.4 0.85 0.013

Monocot- (Wheat) 29.4 >0.86 0.061

 Expressed as %Technical product not cation. 1

 Expressed as lbs cation/A cation.

2

The terrestrial plant testing guideline requirements are fulfilled. (MRID #

426396-01, 426010-01)

(2) Aquatic

Currently, aquatic plant testing is required for any herbicide which has outdoor

non-residential terrestrial uses that may result in offsite movement by runoff

(solubility >10 ppm in water), by drift (aerial or irrigation), or is applied directly to

aquatic use sites (except residential). Since the use patterns for paraquat dichloride

may allow off site movement as a result of drift from either ground or aerial

application, aquatic plant testing is required.

The following species should be tested: Selenastrum capricornutum, Lemna

gibba, Skeletonema costatum, Anabaena flos-aquae, and a freshwater diatom. 

Tier 2 Toxicity data on the technical/TEP material are summarized in the

following table.
71

Nontarget Aquatic Plant Toxicity Findings 

Species % A.I. NOEC/LOEC/EC MRID NO. Fulfills Guideline 1

50

 (ppb) 2 Author/Year Requirement

Navicula

pelliculosa

(Freshwater

diatom)

32.7 0.22 / 0.45 / 426010-06 Yes

0.55ppb Smyth et al/1992

Lemna gibba 32.7 16 / 32 / 98ppb 426010-03 Yes

Smyth et al/1992

Selenastrum

capricornutum

32.7 0.08 / 0.20 / 426010-02 Yes

0.32ppm Smyth et al/1992

Skeletonema

costatum

32.7 0.22 / 0.47 / 426010-04 Yes

2.84ppm Smyth et al/1992

Anabaena flosaquae

32.7 3.2 / 6.3 / 15 ppb 426010-05 Yes

Smyth et al/1992

Expressed as % Technical product not cation. 1

Expressed as ppb Technical.

2

The guideline requirements are fulfilled. (MRID #s 426010-02, -

03, -04, -05, -06)

2. Environmental Fate

The environmental fate data base for paraquat dichloride is sufficiently

complete to make a thorough fate assessment for paraquat for the following

registered uses: terrestrial food crops (field, vegetable, and orchard), terrestrial

non-food crops (ornamentals and turf), terrestrial noncrop, forestry (directed

sprays in shelter belts and pine resin soaking), and domestic outdoor sites.

a. Environmental Fate Assessment

The primary route of environmental dissipation of paraquat

dichloride is adsorption to biological materials and soil clay particles. 

Paraquat dichloride has been shown to adsorb to clay crystalline lattices

with no apparent correlation between organic matter content and

paraquat adsorption. Paraquat dichloride does not hydrolyze, does not

photodegrade in aqueous solutions, and is resistant to microbial

degradation under aerobic and anaerobic conditions. Essentially no

microbial degradation of paraquat was seen after 180 days of aerobic

incubation or after 60 days of anaerobic incubation following a 30-day

aerobic incubation. 
72

Paraquat dichloride was shown to be very immobile in soil with

batch equilibrium studies conducted on four soils in the laboratory. 

High rates of paraquat were added because at realistic field application

rates, paraquat was below detection in the batch equilibrium adsorption

solution. Adsorption Kd's ranged from 68-50,000 ml/g, and there was

no detectable desorption. 

In laboratory studies with radiolabeled paraquat, no radioactivity

volatilized from the soil surface to adsorb to glass or to collect in

volatile traps. With low vapor pressure and extremely high adsorption

coefficients, paraquat would not be expected to volatilize once applied

to the soil. However, spray drift could potentially be a problem because

paraquat is extremely biologically active and toxic to plants and animals

before it becomes adsorbed to clay particles in the soil and therefore

biologically unavailable.

In short- and long-term field dissipation studies, paraquat

residues were extractable only by refluxing with 6 M sulfuric acid and

were shown to be persistent and to accumulate slightly with repeated

applications. Paraquat dichloride is inactivated (dissipated) by rapid

adsorption to clay particles. Due to the apparent adsorption strength of

paraquat for soil clays, these bound residues do not appear to be

environmentally available. Adsorbed radiolabeled paraquat did undergo

isotopic exchange when soil samples were shaken with a highly

concentrated, non-labeled paraquat solution (7440 ppm paraquat in

water). Therefore, the potential for desorption does exist; however,

since there was no apparent exchange with calcium chloride in the batch

equilibrium study, this exchange will probably not affect the

environmental behavior of paraquat. 

Paraquat dichloride is very persistent and could potentially be

found in surface water systems associated with soil particles carried by

erosion. Paraquat dichloride is not expected to be a contaminant of

groundwater. A minor photodegradate, 4-carboxy-1-methylpyridinium

(QINA) which comprised 6% of applied radioactivity after 85 weeks of

natural sunlight irradiation, was determined to be mobile. According to

the field data reviewed in this submission, paraquat degraded very

slowly. Therefore, the minor photodegradate, QINA, would apparently

not be an important environmental concern.
73

b. Environmental Fate, Chemistry, and Transport

(1) Degradation

(a) Hydrolysis (161-1)

The hydrolysis data requirement is fulfilled. 

Paraquat dichloride at 91 ppm did not hydrolyze at pH 5,

7, and 9 when incubated at 25 or 40o C. (Upton, Hendley,

and Skidmore, 1985. No MRID).

(b) Photodegradation in Water (161-2)

The photolysis in buffered solution data

requirement is fulfilled. Paraquat dichloride at 28 ppm in

sterile pH 7 aqueous buffer solution did not photodegrade

when continuously irradiated with a xenon arc lamp for

32 days at 25o C. Paraquat dichloride accounted for 90.2-

98.0% of the applied radioactivity throughout the study in

the irradiated and dark control samples; no degradates

were reported from TLC or HPLC analyses. Volatiles

were trapped during this experiment and 0.15% of the

applied radioactivity was recovered as CO2. (MRID

40562301)

(c) Photodegradation on Soil (161-3)

The photodegradation on soil surfaces data

requirement is fulfilled. Paraquat dichloride did not

photodegrade when mixed with a sterile soil and exposed

to natural sunlight for 85 weeks. (Pack, 1982, no MRID).

(d) Aerobic soil metabolism (162-1)

The aerobic soil metabolism data requirement is

fulfilled. Paraquat dichloride at 4.32 ppm did not

degrade in sandy loam soil incubated under aerobic

conditions at 20 + 2o C for 180 days. Paraquat dichloride

comprised 93% of the applied radioactivity at 180 days

posttreatment. Most of the radioactivity was extracted

with technical grade paraquat by isotopic exchange. 

There was no volatile radioactivity. No degradates were
74

reported from TLC or HPLC analyses. (MRID

41319301)

(e) Anaerobic soil metabolism (162-2)

The anaerobic soil metabolism data requirement is

fulfilled. Paraquat dichloride at 4.32 ppm did not

degrade in sandy loam soil incubated under anaerobic

conditions for 60 days following a 30-day aerobic

incubation. Paraquat dichloride comprised 88.8% of the

applied radioactivity at 90 days posttreatment [60 days of

anaerobic incubation]. Most of the radioactivity was

extracted with technical grade paraquat by isotopic

exchange. A trace amount of radioactivity (0.29% of

applied) was recovered in the water phase at 61 days

posttreatment [30 days postflooding]. There was no

volatile radioactivity. No degradates were reported from

TLC or HPLC analyses. (MRID 41319302)

(f) Anaerobic aquatic metabolism (162-3)

No studies were submitted; however, none are

required since an acceptable anaerobic soil metabolism

study was submitted.

(g) Aerobic aquatic metabolism (162-4)

Although no studies were required, one study was

submitted and reviewed in 1985. This study included an

aerobic aquatic metabolism section with paraquat

dichloride applied to the surface of soil:water systems in

plastic swimming pools. Paraquat dichloride was

removed from the water column with a "resident halflife" of <2 weeks. The soil layer was not sampled. This

study was considered scientifically valid, but does not

fulfill guideline requirements. (MRID 00055093) 

(2) Mobility

(a) Leaching, adsorption/desorption (163-1)

The unaged mobility data requirement is fulfilled. 

Paraquat dichloride was immobile in silty clay loam,
75

loam, loamy sand, and sand soils. It was not possible to

determine Freundlich K values because no paraquat ads

was detected in the adsorption solution at the lower

application rates. At high application rates (50-1000

times the field application rate), Kads values ranged from

at 68-50,000 ml/g . There was no desorption of paraquat

from these soils. (MRID 40762701)

The aged mobility data were not required.

(3) Accumulation

The fish bioaccumulation data requirement was waived. 

The logK for paraquat dichloride is -4.5 at 20 C indicating that ow

o

bioaccumulation is unlikely.

(4) Field Dissipation

The terrestrial field dissipation data requirement is

fulfilled with one short-term dissipation and four long-term

dissipation studies.

(a) Terrestrial field dissipation (164-1)

Paraquat dichloride degraded very slowly in

Delaware on a loamy sand soil which was planted to

soybeans. Residues decreased from an average of 1.1

mg/kg soil immediately posttreatment to 0.76 mg/kg at 86

days posttreatment and remained at 0.42-0.50 mg/kg

from 296 to 657 days posttreatment. Paraquat dichloride

did not leach below the 0- to 3.5-inch soil depth and was

only recovered at the detection limit of 0.05 mg/kg in the

4.5- to 10-inch soil segment from one subplot at 296 days

posttreatment. 

(b) Dissipation -- Long term field (164-5)

Four long term field dissipation studies were

reported with data from: Champaign, Illinois (MRID

42802101); Visalia, California (MRID 42738701);

Leland, Mississippi (MRID 42738702); and Pikeville,

North Carolina (MRID 42802102). Paraquat dichloride
76

was applied in three or four single annual applications to

plots of bare ground, corn, peach trees, soybeans, and

cotton.

Acid-reflux extractable paraquat did not

appreciably degrade at any of the four sites from which

data were provided. Half-lives were not calculated in any

study although the study authors cited references of field

studies with paraquat half-lives of >10 years. In these

four studies, paraquat generally did not leach below the

3.5-inch depth. 

Paraquat dichloride was stable for 1376 days (45

months) in soil samples treated at 1.0 mg/kg and stored

frozen at -14o C. (MRID 42738703) 

(c) Aquatic field dissipation (164-1)

No studies are required because there are no

aquatic uses for paraquat.

(5) Spray Drift

Spray drift data are required by 40 CFR Sec. 158.142

when aerial application and/or mist blower or other ground

application are proposed and it is expected that the effect levels

for nontarget organisms (humans, domestic animals, fish,

wildlife, and nontarget plants) expected to be present, are

exceeded. 

Droplet size spectrum (201-1) and drift field evaluation

(202-1) data are required. The registrant (Zeneca) may elect to

satisfy these data requirements through the Spray Drift Task

Force, provided that these data are not required in advance of the

Task Force's final report. If the registrant wishes to satisfy these

data requirements in this manner, the procedures outlined in PR

Notice 90-3 should be followed.

c. Water Resources

Although there were detections of paraquat in drinking water

wells from two states cited in the Pesticides in Groundwater Database,

these detections are not considered to be representative of normal
77

paraquat use. Paraquat dichloride binds strongly to soil clay particles

(Kd 68-50,000 mL/g) and did not leach from the surface in the

terrestrial field dissipation studies. Therefore, paraquat is not

considered to be a groundwater concern from normal use patterns.

3. Exposure and Risk Characterization

 Paraquat dichloride is applied primarily as a broadcast treatment by

aerial and ground equipment but is also applied as a bark treatment, bore-hole

treatment, tree injection treatment, basal spray and spot treatment by a variety

of other methods. The non-broadcast treatment methods above, because of

limited application sites and application rates ranging from 3.3 x 10 to 1 lb -4

cation/A, are not expected to pose significant risk to non-target wildlife and

will not be considered further in this risk assessment. Instead, the Ecological

Exposure and Risk Characterization that follows will be concerned only with

the aerial and ground broadcast application uses of paraquat dichloride and

their effect on non-target and endangered species.

a. Ecological Exposure and Risk Characterization

Explanation of the Risk Quotient (RQ) and the Level of Concern

(LOC): The Levels of Concern are criteria used to indicate potential

risk to nontarget organisms. The criteria indicate that a chemical, when

used as directed, has the potential to cause undesirable effects on

nontarget organisms. There are two general categories of LOC (acute

and chronic) for each of the four nontarget faunal groups and one

category (acute) for each of two nontarget floral groups. In order to

determine if an LOC has been exceeded, a risk quotient must be derived

and compared to the LOC's. A risk quotient is calculated by dividing an

appropriate exposure estimate, e.g. the estimated environmental

concentration, (EEC) by an appropriate toxicity test effect level, e.g. the

LC . The acute effect levels typically are: 50

-EC (terrestrial plants), 25

-EC (aquatic plants and invertebrates), 50

-LC (fish and birds), and 50

-LD (birds and mammals) 50

The chronic test results are the: 

-NOEL (or the NOEC) for avian and mammal reproduction studies, and

either the NOEL for chronic aquatic studies, or the Maximum

Allowable Toxicant Concentration (MATC), which is the geometric
78

mean of the NOEL and the LOEL (or LOEC) for chronic aquatic

studies.

When the risk quotient exceeds the LOC for a particular category, risk

to that particular category is presumed to exist. Risk presumptions are

presented along with the corresponding LOC's.

Levels of Concern (LOC) and associated Risk Presumption

Mammals, Birds

IF THE LOC PRESUMPTION

acute RQ 0.5 High acute risk

acute RQ 0.2 Risk that may be mitigated

through restricted use

acute RQ 0.1 Endangered species may be

affected acutely

chronic RQ 1 Chronic risk, endangered

species may be affected

chronically,

Fish, Aquatic invertebrates

IF THE LOC PRESUMPTION

acute RQ 0.5 High acute risk

acute RQ 0.1 Risk that may be mitigated

through restricted use

acute RQ 0.05 Endangered species may be

affected acutely

chronic RQ 1 Chronic risk, endangered

species may be affected

chronically

Plants

IF THE LOC PRESUMPTION

RQ 1 High risk

RQ 1 Endangered plants may be

affected

Currently, no separate criteria for restricted use or chronic effects for

plants exist.
79

(1) Exposure and Risk to Nontarget Terrestrial Animals

(a) Birds

Acute

Residues found on dietary food items following

paraquat dichloride application may be compared to LC50

values to predict acute risk. The maximum estimated

environmental concentrations (EECs) of residues of

paraquat dichloride which may be expected to occur on

selected avian or mammalian dietary food items

following a single application are provided in the table

below along with the respective risk quotients (RQs) and

pertinent LOCs.

 

Avian RQs based on a Bobwhite quail LC of 714 ppm (cation) 50

Food items Maximum Application Rates1 EEC RQ

(lbs cation/A) (ppm) (EEC/

(cation) LC ) 50

Short Grass

0.07 16.80 0.02

1.0 240.00 0.34**

1.6 384.00 0.54***

Long Grass

0.07 7.70 0.01

1.0 110.00 0.15

1.6 176.00 0.25**

Broadleaf Plants/

Small Insects

0.07 9.45 0.01

1.0 135.00 0.19*

1.6 216.00 0.30**

Fruits/

Large Insects/

Seeds

0.07 1.05 0.00

1.0 15.00 0.02

1.6 24.00 0.03

0.07lb/A = lowest maximum application rate for broadcast uses 1

1.0 lb/A = typical maximum application rate for food and non-food/non-feed uses

1.6 lb/A = absolute maximum application rate for various food uses

* Exceed Endangered species (ESP) LOC (ESP LOC 0.1)

** Exceeds ESP LOC 0.1 and Restricted Use (RU) LOCs (RU LOC 0.1 and 0.2)

*** Exceeds ESP, RU and High Acute Risk (HR) LOCs (HR LOC 0.5)
80

Results indicate that the high acute risk, restricted

use and endangered species LOCs are exceeded for birds

at application rates at or above 1.49, 0.60 and 0.3 lbs

cation/A respectively. Therefore the use of paraquat

dichloride at higher rates is expected to pose acute risk to

non-target avian species. However, because of the

environmental fate of the chemical, the risk posed by

paraquat only exists shortly after application. Once the

applied paraquat has dried (usually within 4 hours), its

risk is greatly reduced. It should be noted that the

potential exists for the paraquat to again pose risk as a

result of rewetting by rain, dew or humidity but at a much

lower level. 

Chronic

Residues found on dietary food items following

paraquat dichloride application may be compared to

NOEC values to predict chronic hazard. The maximum

estimated environmental concentration (EEC) of residues

of paraquat dichloride which may be expected to occur

on selected avian dietary food items following a single

application is provided in the table below along with the

respective risk quotients (RQs) and pertinent LOCs. 

Chronic Risk Quotients (RQs) based on a Mallard duck NOEL of 30 ppm (cation) 

(RQs and EECs expressed as cation) 1

Food items Maximum Application EEC RQ

Rates (ppm) (EEC/ 2

(lbs cation./A ) NOEL)

Short Grass

0.07 16.80 0.56

1.0 240.00 8.00*

1.6 384.00 12.80*

Long Grass

0.07 7.70 0.26

1.0 110.00 3.67*

1.6 176.00 5.87*

Broadleaf Plants/

Small Insects

0.07 9.45 0.32

1.0 135.00 4.50*

1.6 216.00 7.20*
Chronic Risk Quotients (RQs) based on a Mallard duck NOEL of 30 ppm (cation) 

(RQs and EECs expressed as cation) 1

Food items Maximum Application EEC RQ

Rates (ppm) (EEC/ 2

(lbs cation./A ) NOEL)

81

Fruits/Large Insects/

Seeds

0.07 1.05 0.04

1.0 15.00 0.50

1.6 24.00 0.80

 0.07lb/A = lowest maximum application rate for broadcast uses 1

 1.0 lb/A = typical maximum application rate for food and non-food/non-feed uses

 1.6 lb/A = absolute maximum application rate for various food uses

* Exceeds Chronic Risk LOC

The above table shows that at rates of 1.0, and 1.6

lbs cation/A the chronic LOCs for avian species are

exceeded. Normally this would indicate a chronic risk to

birds. However, the environmental fate data indicate that

once paraquat is applied and dries, it is not expected to

pose a risk. If it is washed off plant surfaces, it is very

strongly adsorbed to clay particles in the soil and

therefore not biologically available. Therefore, the

registered uses of paraquat dichloride are not expected to

pose a chronic risk to avian species. 

Although a chronic risk is not expected as the

result of residues on dietary food items, the Agency is

concerned that the use of paraquat dichloride may affect

avian reproduction. There is evidence to show that

following direct application at rates of 0.5 and 5.0 lbs

cation/A to mallard duck eggs, paraquat can cause a

reduction of hatchability, significant mortality and

reduced growth (MRIDs 00110453, 00110454,

00110455, 00162746). 

(b) Mammals

Acute

Small mammal exposure is addressed using acute

oral LD values converted to estimate a LC value for 50 50

dietary exposure. The estimated LC50 is derived using the

following formula:

LC = LD 50 50

 % of body weight consumed
82

Mammals can be separated into five general

groups according to food habits: herbivores, insectivores,

granivores, omnivores and carnivores. For the purposes

of this risk assessment only three groups will be

considered; herbivores, insectivores and granivores. 

Risk quotients were calculated using the

calculated LC50's and the EEC's for the 0.07, 1.0, and 1.6

lbs cation/A application rates. These are summarized

along with the LOC exceedances in the following tables.
83

Mammalian Herbivore/Insectivore RQs (based on a female rat LD50 of 206 mg/kg) and EECs expressed as cation

Appl. Body % Body wt. Est. EEC EEC EEC RQ RQ RQ

Rate Weight Consumed mg/kg/d Short Grass Broadleaf Fruits and Short Grass Broadleaf Fruits and

lbs (g) in diet Plants/ Large Plants/ Large

cation/A Small Insects Small Insects

Insects Insects

0.07 35 66 312.12 16.80 9.45 1.05 0.05 0.03 0.00

15 95 216.84 0.08 0.04 0.00

1000 15 1,373.33 0.01 0.01 0.00

1.0 240.00 135.00 15

15 95 216.84 1.11 20.62 0.07

*** ***

35 66 312.12 0.77 0.05

***

0.43**

1000 15 1,373.33 0.17* 0.10* 0.01

1.6 384.00 216.00 24

15 95 216.84 1.77 1.00

*** ***

0.11*

35 66 312.12 1.23 0.69 0.08

*** ***

1000 15 1,373.33 0.28** 0.16* 0.02

* Exceeds ESP LOC

** Exceeds RU and ESP LOCs

*** Exceeds HR, RU and ESP LOCs

Mammalian GranivoreRQs (based on a female rat LD50 of 206 mg/kg) and EECs expressed as cation

Appl. Rate Body Weight % Body wt. Est. mg/kg/d EEC seeds RQ

lbs cation./A (g) Consumed in diet

0.07 35 15 1,373.33 1.05 0.00

15 21 980.95 0.00

1000 3 6,866.67 0.00

1.0 35 15 1,373.33 15 0.01

15 21 980.95 0.02

1000 3 6,866.67 0.00

1.6 35 15 1,373.33 24.00 0.02

15 21 980.95 0.02

1000 3 6,866.67 0.00

The two tables above show that for the lowest

application rate, 0.07 lbs cation/A, no LOCs are exceeded

for any exposure scenarios. As such, at application rates

of 0.07 lbs cation/A or below, the registered uses of

Paraquat dichloride are not expected to pose acute risk to

non- endangered mammalian species. Also, the

registered uses of Paraquat dichloride are not expected to

pose acute risk to any granivorous mammals at

application rates up to and including 1.6 lbs a.i./L.

The application rate of 1.0 lbs cation/A may

produce residues on grass that result in risk quotients that

exceed HR, RU and ESP LOCs for small and medium

herbivorous and small insectivorous mammals. Restricted

use LOCs are exceeded for medium insectivorous

mammals. Endangered species LOCs are exceeded for

large herbivorous and insectivorous mammals. The

highest application rate of 1.6 lbs cation/A (food and feed

uses) produces residues in grass that result in risk
84

quotients that exceed HR, RU and ESP LOCs for small

and medium herbivorous and insectivorous mammals,

restricted use LOCs for large herbivorous mammals and

endangered species LOCs for large insectivorous

mammals. However, because of the environmental fate

of the chemical, the risk posed by paraquat only exists

shortly after application. Once the applied paraquat has

dried, its risk is greatly reduced. It should be noted that

the potential exists for paraquat to again pose risk as a

result of rewetting by rain, dew or humidity, but this risk

is at a much lower level.

Chronic

Residues found on dietary food items following

paraquat dichloride application may be compared to

NOEC values to predict chronic risk. The maximum

estimated environmental concentrations (EECs) of

residues of paraquat dichloride which may be expected to

occur on selected mammalian dietary food items

following a single application is provided in the table

below along with the respective risk quotients (RQs) and

pertinent LOCs. The EECs and the RQs are summarized

in the following table. 
85

 

Chronic risk quotients based on a 12 week study with Wistar-Derived Alderley Park Strain Rats resulting in a NOEL of 25 ppm (cation) and EECs (expressed as

cation)

Food items Maximum Application Rates1 EEC RQ

(lbs cation/A ) (ppm) (EEC/NOEL)

Short Grass

0.07 16.80 0.67

1.0 240.00 9.6*

1.6 384.00 15.36*

Long Grass

0.07 7.70 0.31

1.0 110.00 4.4*

1.6 176.00 7.04*

Broadleaf Plants

0.07 9.45 0.38

1.0 135.00 5.4*

1.6 216.00 8.64*

Fruits

0.07 1.05 0.04

1.0 15.00 0.60

1.6 24.00 0.96*

0.07lb/A = lowest maximum application rate for broadcast uses 1

 1.0 lb/A = typical maximum application rate for food and non-food/non-feed uses

 1.6 lb/A = absolute maximum application rate for various food uses

* Exceeds Chronic LOC

The above table shows that at rates of 1.0, and 1.6

lbs cation/A the chronic LOCs for mammals are

exceeded. Normally this would indicate a chronic risk to

mammals. However, environmental fate data indicate

that paraquat once applied and dried is not expected to

pose risk and if washed off plant surfaces is very strongly

adsorbed to clay particles in the soil and therefore not

biologically available. Therefore, the registered uses of

paraquat dichloride are not expected to pose a chronic

risk to mammalian species. 

(c) Insects

Laboratory data indicates that, based on the

application of dry crystalline and liquid formulations of

technical and Technical End-Product (TEP) Paraquat

dichloride, the contact LD50 to honey bees ranged from

6.04->144 ug/bee. This classifies Paraquat dichloride as

relatively non-toxic to bees. Another study (MRID#

#00111488) shows that when Paraquat dichloride CL

(formulated product) was sprayed on honey bees at the

rate of 4 lbs cation/A, 55% mortality was observed after 2

days and 90% mortality after 3 days. The study, in which

Paraquat in combination with a surfactant was sprayed at

rates 2.5 to 4 times maximum label rates, seems to

indicate that potential for risk to honey bees may exist as
Values used are; 1% drift for ground application and 5% drift for aerial application 1

 The concentration of a pesticide expected in a 1 Acre pond, 6 ft. deep, following application of 1 lb/A. 2

86

a result of direct contact with paraquat sprayed at labeled

rates. However, the extent of the risk, if any, is expected

to be very minimal because paraquat technical is

classified as relatively nontoxic to honey bees and

because, for most of the major uses, paraquat will be

applied at times when honey bees will not be active in the

field

(2) Exposure and Risk to Nontarget Aquatic Animals

Risk to nontarget aquatic animals is assessed by

comparing actual or estimated environmental concentrations

(EECs) to toxicity data and calculating Risk Quotients (RQs). 

These RQs are then compared to the LOCs to assess the potential

for risk to non-target aquatic animals. Aquatic EECs are

generally considered the result of direct application to water or

the additive effect of runoff or drift. The EECs used in risk

assessments are usually obtained either by utilizing the GENEEC

Model as an initial screening tool or more advanced models to

obtain more refined values. Both types of models utilize fate

data including hydrolysis and photolysis half lives, Koc, Kads,

solubility, etc. Because paraquat dichloride dissipates by

binding very strongly to clay minerals in soils, using models that

depend on degradation parameters would yield inappropriate

EEC predictions. Due to paraquat dichloride's strong adsorption

to soil, no aquatic residues are expected as a result of runoff. 

The only residues expected are those resulting from drift of

paraquat dichloride during application. The following formula

was used to calculate EECs due to drift.

EEC = Application Rate X %drift X 61ppb 1 2

The following table lists the EECs and resultant RQs

expected following application of paraquat dichloride at

registered label rates. 
87

Application Rate

(lb/A)

Acute Risk Quotients (RQs for the Most Sensitive Aquatic Organism (Daphnia magna EC = 1.2 ppm) 50

Drift Drift

Ground Aerial Application

Application (lb cation/A)

(lb cation/A)1

1

Exposure Scenario

Residues from Residues from RQs RQs

Ground Aerial Application (Ground (Aerial

Application (ppb) (ppb) Application) Application) 2 2

0.07 0.001 0.004 0.043 0.214 0.000 0.000

1 0.010 0.050 0.610 3.050 0.001 0.003

1.6 0.016 0.080 0.976 4.880 0.001 0.00

Values used are; 1% drift for ground application and 5% drift for aerial application.

1

 The concentration of a pesticide expected in a 1 Acre pond, 6 ft. deep, following application of 1 lb/A. 2

Comparing the RQs to the LOCs (High acute risk LOC 0.5;

Restricted Use LOC 0.1; Endangered species LOC 0.05), no LOCs are

exceeded. Therefore, the registered uses of paraquat dichloride are not

expected to pose an acute risk to any aquatic organisms.

(3) Exposure and Risk to Nontarget Plants

(a) Terrestrial and Semi-aquatic

Non-target terrestrial plants inhabit areas which are dry. Non-target

semi-aquatic plants are plants that usually inhabit low-lying wet areas that may

be dry in certain times of the year. These plants are not obligatory aquatic

plants in that they do not live in a continuously aquatic environment. The

terrestrial and semi-aquatic plants may be exposed to pesticides from runoff,

drift or volatilization. 

Spray drift exposure from ground and aerial application (including

airblast, forced-air, and chemigation applications) is assumed to be 1 and 5%

respectively, of the application rate. 

As was stated previously, paraquat dichloride binds strongly to soil and

it is therefore not expected to affect non-target terrestrial and semi-aquatic

plants as a result of runoff. Therefore, the risk of the use of paraquat

dichloride to non-target terrestrial and semi-aquatic plants is expected to come

only as a result of drift during application. The EECs were calculated using

the following formulas:

EEC Formulae 

Calculating EECs for terrestrial plants inhabiting areas adjacent to treatment

sites: 
88

Unincorporated ground application:

Drift = maximum application rate x 0.01 

Aerial, airblast, forced-air, and chemigation applications:

Drift = maximum application rate (lbs cation/acre) x 0.05 

Calculating EECs for semi-aquatic plants inhabiting wet, low-lying areas:

Unincorporated ground application:

Drift = maximum application rate x 0.01 

Aerial, airblast, and forced-air applications:

Drift = maximum application rate (lbs cation/acre) x 0.05 

To assess risk, the EECs are then compared to the EC of the most 25

sensitive plant species, the Cocklebur (EC25 = 0.013 lb cation/A. The RQs are

then compared to the LOC for plants (LOC=1). The following table lists

EECs and RQs for the registered label rates of paraquat dichloride.
89

Acute High Risk Quotient (RQs) for Terrestrial and Semi-Aquatic Plants 

(based on a Cocklebur vegetative vigor EC of 0.013 lbs cation/A) 50

Application Rate Unincorporated Aerial Application EECs Terrestrial & Terrestrial &

(lb/A) Ground (lb cation/A) Semi-Aquatic Rqs Semi-Aquatic Rqs

(cation) Application EECs (Ground (Aerial

(lb cation/A) Application) Application)

0.0700 0.00 0.00 0.00 0.00

1.0000 0.01 0.05 0.77 3.85*

1.6000 0.02 0.08 1.54* 6.15*

* Exceeds LOC

The use of paraquat dichloride is not expected to

pose risk to non-target terrestrial and semi-aquatic plants

at the lowest application rate of 0.07 lb cation/A. Aerial

application of paraquat dichloride at the 1.0 lb cation./A

rate is expected to pose risk to non-target terrestrial and

semi-aquatic plants due to drift. Ground application at

the same rate is not expected to pose risk. At the

maximum rate of 1.6 lb cation/A both aerial and ground

application of paraquat dichloride are expected to pose

risk to non-target plants.

Acute Endangered Species Risk Quotient (RQs) for Terrestrial and Semi-Aquatic Plants 

(based on a Cocklebur vegetative vigor NOEL of 0.004 lbs cation/A)

Application Rate Unincorporated Aerial Application EECs Terrestrial & Terrestrial &

(lb/A) Ground (lb cation/A) Semi-Aquatic Rqs Semi-Aquatic Rqs

(cation) Application EECs (Ground (Aerial

(lb cation/A) Application) Application)

0.0700 0.00 0.00 0.00 0.00

1.0000 0.01 0.05 2.50* 12.50*

1.6000 0.02 0.08 5.00* 20.00*

* Exceeds LOC

The use of paraquat dichloride is not expected to

pose risk to endangered terrestrial and semi-aquatic plants

at the lowest application rate of 0.07 lb cation/A. Aerial

and ground application of paraquat dichloride at the 1.0

lb cation./A rate and above are expected to pose risk to

endangered terrestrial and semi-aquatic plants due to

drift. 

(b) Aquatic Plants

Exposure to nontarget aquatic plants may occur

through runoff or spray drift from adjacent treated sites

or, directly from such uses as aquatic weed or mosquito

larvae control. An aquatic plant risk assessment is

usually done for aquatic vascular plants from the

surrogate duckweed Lemna gibba. Non-vascular aquatic

plant risk assessments are performed using either algae or
90

diatom, whichever is the most sensitive species. These

non-vascular plants are useful to determine impact to

food sources of aquatic organisms. Only short term risk

to aquatic plants is estimated. The risk ratio is

determined by dividing the pesticide's initial

concentration in water by the pesticide's EC50 for each

surrogate species.

As was stated previously, paraquat dichloride

binds strongly to soil and it is therefore not expected to

affect non-target aquatic plants as a result of runoff. The

risk of the use of paraquat dichloride to non-target aquatic

plants is expected to come only as a result of drift during

application. In the case of submerged aquatic plants,

such as aquatic algae, diatoms, and submerged

macrophytes, paraquat dichloride exposure results from

aquatic residues resulting from spray drift. In the case of

floating aquatic plants, such as duckweed, waterlilies,

etc., exposure results not only from aquatic residues but

also from direct contact with pesticide drift. The

following table lists the EECs expected resulting from

ground and aerial application of paraquat dichloride at

registered label rates. The EECs were calculated using

the same formulas as used for the aquatic organism risk

assessment and only reflect aquatic residues resulting

from spray drift. 

Acute RQ's and EEC's for duckweed and the

diatom, Navicula pelliculosa, are shown in the Tables

below.
91

Estimated Environmental Concentrations (EECs) and Acute Risk Quotients (RQ) for Aquatic Plantsbased upon a duckweed EC50 of 0.0713 ppm and a non

vascular plant the diatom Navicula pelliculosa EC50 of 0.40 ppb.

Rate of Water from of Water from (Ground (Aerial

Application Surrogate Plant Drift from Drift from Application) Application)

(lb cation/A) Ground Aerial (EEC/ (EEC/

EC50

(ppb)

Aquatic Aquatic

Residue in 6' of Residue in 6' RQ RQ

Application Application EC50) EC50)

(ppb) (ppb)

0.07 0.04 0.21

duckweed

Lemna gibba 71.3 0.0006 0.0029

diatom

Navicula 0.4 0.1000 0.5250

pelliculosa

1 3.05

duckweed

Lemna gibba 71.3 0.0086 0.0428

0.61

diatom

Navicula 0.4 1.5250 7.6250

pelliculosa

1.6 4.88

duckweed

Lemna gibba 71.3 0.0137 0.0684

0.98

diatom

Navicula 0.4 2.45 12.2000

pelliculosa

The above results indicate that for aquatic plants

high acute risk LOCs are not exceeded for rates equal to

or below 1.6 lb cation/A for non-target vascular plants as

a result of ground or aerial applications of paraquat

dichloride. Aquatic plants high acute risk LOCs are not

exceeded for rates equal to or below 0.07 lb cation/A for

non-target non-vascular plants as a result of ground or

aerial applications of paraquat dichloride, but are

exceeded at the 1.0 and 1.6 lb cation/A rates. Currently,

no separate criteria for restricted use or chronic effects for

plants exist.

In order to assess the risk of paraquat dichloride to

endangered plants, the same formulas were used to

calculate the EECs. However, the RQs were calculated

using NOEC values in the place of EC50 values and are

summarized in the following table. 
92

Estimated Environmental Concentrations (EECs) and Endangered Species Risk Quotients (RQ) for Aquatic Plants based upon the Lemna gibba NOEC of 

16 ppb. 

Rate of of Water from of Water from (Ground (Aerial

Application Surrogate Plant Drift from Drift from Application) Application)

(lb cation/A) Ground Aerial (EEC/ (EEC/

NOEC

(ppb)

Aquatic Aquatic

Residue in 6' Residue in 6' RQ RQ

Application Application EC50) EC50)

(ppb) (ppb)

0.07 Lemna gibba 11.6 0.04 0.21 0.00 0.02

1 Lemna gibba 11.6 3.05 0.05 0.26 0.61

1.6 Lemna gibba 11.6 4.88 0.08 0.42 0.98

Based on the calculated RQs, the LOCs are not exceeded

for endangered aquatic plants. Therefore, the registered uses of

paraquat dichloride are not expected to pose risk to non-target

endangered aquatic plants.

(4) Endangered Species

Levels of Concern have been exceeded for endangered

species of birds at application rates greater than or equal to 0.30

lb cation/A. Levels of Concern have also been exceeded for

endangered mammalian species for all labeled application rates >

0.55 lb cation/A. These risks exist only until the paraquat

dichloride residue dries or becomes bound.

LOCs for endangered aquatic organisms have not been exceeded

at even the highest rate of 1.6 lbs cation/A. Levels of Concern

have been exceeded for endangered terrestrial and semi-aquatic

plants at the 1.0 lb cation/A application rate. The endangered

species LOCs for aquatic plants are exceeded at the 1.0 and 1.6

lb cation/A rates for ground application and at all rates for aerial

application.

 

When the Endangered Species Protection Program

becomes final, limitations in the use of paraquat dichloride may

be required to protect endangered and threatened species, but

these limitations have not been defined and may be formulation

specific. The Agency anticipates that a consultation with the

Fish and Wildlife Service may be conducted in accordance with

the species-based priority approach described in the Program. 

After completion of consultation, registrants will be informed if

any required label modifications are necessary. Such

modifications would most likely consist of the generic label
93

statement referring pesticide users to use limitations contained in

county Bulletins.

IV. RISK MANAGEMENT AND REREGISTRATION DECISION

A. Determination of Eligibility

Section 4(g)(2)(A) of FIFRA calls for the Agency to determine, after

submission of relevant data concerning an active ingredient, whether products

containing the active ingredients are eligible for reregistration. The Agency has

previously identified and required the submission of the generic (i.e. active ingredient

specific) data required to support reregistration of products containing paraquat

dichloride as an active ingredient. The Agency has completed its review of these

generic data, and has determined that the data are sufficient to support reregistration of

all products containing paraquat dichloride under the conditions specified in the RED. 

Appendix B identifies the generic data requirements that the Agency reviewed as part

of its determination of reregistration eligibility of paraquat dichloride, and lists the

submitted studies that the Agency found acceptable.

The data identified in Appendix B were sufficient to allow the Agency to assess

the registered uses of paraquat dichloride and to determine that paraquat dichloride can

be used without resulting in unreasonable adverse effects to humans and the

environment if used according to the label as amended by this RED. The Agency

therefore finds that all products containing paraquat dichloride as the active ingredient

are eligible for reregistration under the conditions specified in this RED. The

reregistration of particular products is addressed in Section V of this document. 

The Agency made its reregistration eligibility determination based upon the

target data base required for reregistration, the current guidelines for conducting

acceptable studies to generate such data, published scientific literature, etc. and the

data identified in Appendix B. Although the Agency has found that all uses of

paraquat dichloride are eligible for reregistration under the conditions specified in this

RED, it should be understood that the Agency may take additional appropriate

regulatory action, and/or require the submission of additional data to support the

registration of products containing paraquat dichloride, if new information comes to

the Agency's attention or if the data requirements for registration (or the guidelines for

generating such data) change.

B. Determination of Eligibility Decision

1. Eligibility Decision
94

The Agency has determined that paraquat dichloride products, labeled

and used as specified in this Reregistration Eligibility Decision, will not pose

unreasonable risks or adverse effects to humans or the environment. Under the

Food Quality Protection Act of 1996, the Agency has determined that there is a

reasonable certainty that no harm will result to infants and children from

aggregate exposure to paraquat dichloride. There are no residential uses of

paraquat dichloride, therefore, there are no risks of dermal or inhalation

exposure to infants, children or the general population. Additionally, paraquat

is not expected to be a contaminant of drinking water. The Agency has also

concluded that there are no other chemicals with a common mode of toxicity as

that of paraquat. Therefore, the Agency concludes that products containing

paraquat dichloride for all uses are eligible for reregistration as specified in this

RED.

2. Eligible and Ineligible Uses 

The Agency has determined that all uses of paraquat dichloride are

eligible for reregistration under the conditions specified in this RED.

C. Regulatory Position

The following is a summary of the regulatory positions and rationales for

paraquat dichloride. Where labeling revisions are imposed, specific language is set

forth in Section V of this document.

1. Food Quality Protection Act Findings

a. Determination of Safety for U.S. Population

EPA has determined that the established tolerances with

amendments and changes as specified in this document for paraquat

meet the safety standards under the FQPA amendments to section

408(b)(2)(D) for the general population. In reaching this determination,

EPA has considered the available information on the aggregate

exposures (both acute and chronic) from non-occupational sources, food

and drinking water, as well as the possibility of cumulative effects from

paraquat and other bipyridylium compounds that may have a similar

mode/mechanism of toxicity.

Since there are no residential or non-occupational uses of

paraquat, no dermal or inhalation exposure is expected in and around

the home. Additionally, paraquat residues are not expected to be found

in either groundwater or drinking water.
95

No acute toxicity endpoints of concern have been identified for

paraquat.

The chronic dietary risk assessment showed the percent of the

RfD utilized by dietary exposure to residues of paraquat is 10% for the

general U.S. population. Therefore, the Agency concludes that

aggregate risks for the general population resulting from paraquat uses

are not of concern.

In evaluating the potential for cumulative effects, EPA compared

structural similarities and toxic effects seen in paraquat studies with

other bipyridylium compounds such as diquat dibromide. The Agency

determined that diquat and paraquat have different effects. Paraquat is a

lung toxicant and diquat is not. Paraquat appears to be a weaker

cataractogenic agent then diquat. Therefore, based on available data the

Agency does not believe that the toxic effects produced by paraquat

would be cumulative with the toxic effects produced by diquat.

b. Determination of Safety for Infants and Children

EPA has determined that the established tolerances for paraquat,

with amendments and changes as specified in this document, meet the

safety standards under the FQPA amendments to section 408(b)(2)(C)

for infants and children. The safety determination for infants and

children considers the factors noted above for the general population,

but also takes into account the possibility of increased dietary exposure

due to the specific consumption patterns of infants and children, as well

as the possibility of increased susceptibility to the toxic effects of

paraquat residues in this population subgroup.

In determining whether or not infants and children are

particularly susceptible to toxic effects from paraquat residues, EPA

considered the completeness of the database for developmental and

reproductive effects, the nature and severity of the effects observed, and

other information.

Based on the current data requirements, paraquat has a complete

database for developmental and reproductive toxicity. In the

developmental studies effects were seen (delayed ossification in the

forelimb and hindlimb digits) in the fetuses only at the same or higher

dose levels than effects in the mother. In the reproduction study, no

effects on reproductive performance were seen. Also because the

NOELs from the developmental and reproduction studies were equal to
96

or greater than the NOEL used for establishing the reference dose, EPA

concludes that it is unlikely that there is additional risk concern for

immature or developing organisms. Finally, the Agency has no

epidemiological information suggesting special sensitivity of infants and

children to paraquat. Therefore, the Agency finds that the uncertainty

factor (100X) routinely used in RfD calculations is adequately

protective of infants and children, and an additional uncertainty factor

is not warranted for paraquat.

EPA estimates that paraquat residues in the diet of non-nursing

infants (less than 1 year) account for 31% of the RfD and 24% of the

RfD for children aged 1-6 years. Further, residues in drinking water are

not expected. Therefore, the Agency has determined that there is

reasonable certainty that dietary exposure to paraquat will not cause

harm to infants and children. 

In deciding to continue to make reregistration determinations

during the early stages of FQPA implementations, EPA recognizes that

it will be necessary to make decisions relating to FQPA before the

implementation process is complete. In making these early, case-by -

case decisions, EPA does not intend to set broad precedents for the

application of FQPA to its regulatory determinations. Rather, these

early decisions will be made on a case-by-case basis and will not bind

EPA as it proceeds with further policy development and rulemaking that

may be required.

If EPA determines, as a result of this later implementation

process, that any of the determinations described in this RED are no

longer appropriate, the Agency will consider itself free to pursue

whatever action may be appropriate, including but not limited to,

reconsideration of any portion of this RED.

2. Tolerance Reassessment

The tolerances listed in 40 CFR §180.205(a) are expressed in terms of

residues of paraquat derived from application of either the bis(methyl sulfate)

or the dichloride salt (both calculated as a cation). A summary of paraquat

tolerance reassessments is presented below in table form.

Sufficient data are available to ascertain the adequacy of the established

tolerances for the following commodities, as defined in 40 CFR §180.205(a): 

acerola; almond hulls; apples; apricots; asparagus; avocados; bananas; barley

grain; bean straw; beans, dry; beans, forage; beans, hay; beans, lima
97

(succulent); beans, snap (succulent); beets, sugar; beets, sugar (tops); broccoli;

cabbage; cacao beans; carrots; cauliflower; cherries; Chinese cabbage; citrus

fruit; coffee beans; collards; corn, fresh (inc sweet corn) (K + CWHR); corn

grain; cottonseed; cucurbits; eggs; figs; guar beans; guava; kiwifruit; lettuce;

mint, hay; nectarines; nuts; olives; onions, dry bulb; onions, green; papayas;

passion fruit; peaches; peanuts; peanut, hay; peanut, hulls; peanut, vines; pears;

peas (succulent); peas, forage; peas, hay; pineapples; pistachio nuts; plums

(fresh prunes); potatoes; poultry, fat; poultry, meat; poultry, mbyp; rhubarb; rye

grain; safflower seed; small fruit; sorghum grain; soybean forage; soybeans;

strawberries; sugarcane; sunflower seeds; turnips (roots); turnips (tops);

vegetables, fruiting; and wheat grain. Some of these commodities need

revisions with respect to commodity definitions to conform with the accepted

commodity names (see the Tolerance Reassessment Summary Table located

below for recommendations in revisions to commodity definitions) and some

are no longer regulated as significant feed items. The phrase "negligible

residue" [designated as "(N)"] will be administratively deleted from all entries

of 40 CFR §180.205(a).

Tolerances for rice grain and rice straw of 0.05 and 0.06 ppm,

respectively, have recently been established (60 FR 7457, 2/8/95) in

conjunction with PP#5F03188. Tolerances for lentils and lentil forage and hay

of 0.3, 0.1, and 0.4 ppm, respectively, have recently been established (60 FR

27421, 5/24/95) in conjunction with PP#4E4359; lentil forage and hay are no

longer considered to be significant feed items and these tolerances will be

revoked.

Label revisions are required for paraquat dichloride uses on pastures and

rangelands in order to reflect the use patterns for which adequate residue data

are available. The individual tolerances for "grass, pasture" and “grass, range"

will be administratively revised to grass, forage at 90 ppm; and grass, hay at 40

ppm. A tolerance for pasture grass hay need not be proposed since this item is

not a recognized RAC (Table I of OPPTS 860.1000).

Label revisions are required for paraquat dichloride uses on alfalfa,

clover, and other legumes (including velvetbean, lespedeza, lupine, sainfoin,

trefoil, vetch, crown vetch, and milk vetch) in order to reflect the use patterns

for which adequate residue data are available. The individual tolerances for

"alfalfa", "birdsfoot trefoil", and "clover" will be redefined as non-grass animal

feeds group, forage at 75ppm and non-grass animal feeds group, hay at

210ppm. A tolerance for alfalfa meal need not be proposed since this item is

not a recognized RAC (Table I of OPPTS 860.1000).
98

The ruminant feeding study is adequate to support the reassessment of

the following tolerances for milk and ruminant tissues: meat: 0.05 ppm; fat:

0.05 ppm, and liver (mybp): 0.05 ppm. However, the tolerance for ruminant

kidney will be raised from 0.3 to 0.5 ppm based on current data. Furthermore,

the commodity definitions will be revised to comply with Table I (of OPPTS

860.1000). While no tolerance would normally be considered necessary for

milk, in the interest of harmonization with CODEX, the Agency recommends

that the current 0.01 ppm tolerance be maintained. Also, all poultry and

poultry commodity tolerances except those for eggs will be revoked

[180.6(a)(3)]; in the interest of harmonization with CODEX, the current 0.01

ppm tolerance for eggs should remain. 

The available field trial data indicate that the current tolerances for

"corn forage" and "corn fodder", each established at 0.05 ppm, will be

administratively increased. Furthermore, the commodity definitions will be

revised to reflect the respective corn types (i.e., field, sweet, and pop) in

compliance with Table I (of OPPTS 860.1000) commodity definitions. The

following tolerances will be administratively amended to distinguish the fodder

of various corn types: corn, field, stover at 6 ppm; corn, pop, stover at 6 ppm;

and corn, sweet, stover at 6 ppm. Additionally, the following tolerances will be

administratively amended to distinguish the forage of various corn types: corn,

field, forage at 3 ppm; and corn, sweet, forage at 3 ppm. Due to the recent

Registration Division approval of use of paraquat dichloride as a harvest aid

(TN940007), the Agency required that additional field trials simulating this use

and a separate grain dust study be performed. 

The established tolerance for soybeans will be administratively

increased from 0.05 ppm to 0.25 ppm. Additional data are required for

soybean grain dust to determine a specific numerical concentration factor; a

tolerance for aspirated grain fractions, as a RAC, may have to be proposed

pending the outcome of the required soybean grain dust study. The registrant

has expressed an intention to propose a lower tolerance for soybean forage at

0.03 ppm and to propose a tolerance for soybean hay at 0.05 ppm. Sufficient

data are available to support these proposed tolerance levels and will be

changed or established accordingly.

The available data indicate that the established tolerance for sorghum

forage is too low. The tolerance will be increased to 0.1 ppm for sorghum

forage. Label revisions are required to establish a 20-day PHI.

No tolerances currently exist for the following cereal grain

commodities: barley straw; popcorn grain; and wheat forage and straw. 

Sufficient field residue data are available to determine appropriate tolerance
99

levels for barley straw, wheat forage and straw, and popcorn grain. These

tolerances will be established at 1 ppm, 0.5 ppm, 1 ppm and 0.05ppm

respectively. 

No field residue data or a tolerance proposal for taro foliage have been

submitted. When the use of paraquat dichloride on taro was registered, Section

B of the petition included a restriction against the use of treated taro leaves for

food or feed purposes; however, this restriction is no longer permitted. The

registrant must submit field residue data and a tolerance proposal for residues

of paraquat dichloride in/on taro foliage.

The Agency now recognizes barley hay, cotton gin byproducts

(commonly called gin trash), and wheat hay as raw agricultural commodities

(Table I of OPPTS 860.1000). Residue data are now required for these

commodities, and appropriate tolerances should be proposed once acceptable

data have been submitted and evaluated. The required data for wheat hay will

be translated to barley hay. 

Crop group tolerances of 0.05 ppm will be established for the members

of the Brassica (cole) leafy vegetables group and pome fruits group. 

Established tolerances for broccoli; cabbage; cauliflower; Chinese cabbage;

collards will be combined under the Brassica group at the tolerance of 0.05

ppm. Established tolerances for apples and pears will be combined under the

pome fruit group at a tolerance of 0.05 ppm. Established tolerances for

apricots;, cherries; nectarines; peaches; and plums will be combined under the

stone fruits group at a tolerance of 0.05 ppm. Label revisions to establish a

maximum seasonal rate and a PHI are required for members of the stone fruits

group.

According to Table I (OPPTS 860.1000), the following items are no

longer recognized RACs, therefore, the established tolerances on these items

will be administratively revoked: fresh hops; hop vines; lentil hay; lentil

forage; bean straw; and peanut vines. In consideration of the designation of

dried hops as a RAC and not a processed food commodity, the entry in 40 CFR

§185.4700 for dried hops will be transferred to 40 CFR §180.205(a). In

addition, the available data indicate that the established tolerance for dried hops

is too low; the Agency will administratively increase the established tolerance

for dried hops, as a RAC, from 0.2 ppm to 0.5 ppm and redefined it as hops,

cone, dried. Additionally, the current tolerance for bean hay is being redefined

as cowpea, hay at 0.4 ppm and bean forage is being redefined as cowpea,

forage at 0.1 ppm. 
100

The established tolerance for "small fruit" will be amended to read

"berries". The present tolerances of 0.05, 0.05, and 0.25 ppm for grapes,

cranberries, and strawberries, respectively, will be considered under the

"Miscellaneous" grouping and listed individually.

The established tolerance for sugar beet tops will be lowered from 0.5

ppm to 0.05 ppm.

The established tolerances for oat grain and rye grain will be revoked

since there are presently no registered uses of paraquat on rye and the registrant

has indicated that they do not wish to support use of paraquat on oats.

A tolerance for corn, field, flour at 0.1 ppm will be established based on a

concentration factor of 1.5x in flour and the reassessed tolerance of 0.05 ppm

for the RAC.

The registrant should propose a tolerance for the processed commodities

of grapes. 

A tolerance of 0.25 ppm will be established for paraquat residues in

pineapple processed residue based on a concentration factor of 4.5x in bran and

the reassessed tolerance of 0.05 ppm for the RAC.

Additionally, a tolerance for residues of paraquat in soybean hulls at 2

ppm will be established based on a concentration factor of 6.1x and the

reassessed tolerance of 0.25 ppm for the RAC.

Further, a tolerance of 3 ppm for residues of paraquat in sugarcane

molasses will be established based on a concentration factor of 5.5x in

blackstrap molasses and the reassessed tolerance of 0.5 ppm for the RAC.

Tolerances Listed Under 40 CFR §180.205(b):

The tolerances listed in 40 CFR §180.205(b) have been established with

regional registration and are expressed in terms of residues of paraquat derived

from application of either the bis (methyl sulfate) or the dichloride salt (both

calculated as a cation). A summary of paraquat tolerance reassessments is

presented in table form below.

Sufficient data are available to ascertain the adequacy of the established

tolerances for the following commodities, as defined in 40 CFR §180.205(b): 

cassava; pigeon peas; taniers; taro (corms); tyfon; and yams. Some of these

commodities need revisions with respect to commodity definitions to conform
101

with the accepted commodity names; see the tolerance reassessment summary

table presented below for recommendations in revisions to commodity

definitions. 

Tolerances Listed Under 40 CFR §185.4700:

Sufficient data are available to ascertain the adequacy of the established

tolerance in 40 CFR §185.4700 for dried hops. The data indicate that the

established tolerance is too low. Since dried hops are now considered a RAC

and not a processed food item, the entry in 40 CFR §185.4700 for dried hops

will be transferred to 40 CFR §180.205(a) [see discussion above under

"Tolerances Listed Under 40 CFR §180.205(a)"].

Tolerances Listed Under 40 CFR §186.4700:

Sufficient data are available to ascertain the adequacy of the established

tolerances in 40 CFR §186.4700 for spent mint hay. However, Table I (OPPTS

860.1000) no longer specifies that data on spent mint hay are needed for

material balance, and a tolerance should not be set for this commodity. 

Therefore, the existing tolerance for spent mint hay at 3 ppm should be

revoked. Additionally, Table II no longer specifies a tolerance is required for

sunflower seed hulls. Therefore, the existing tolerance for sunflower seed hulls

at 6 ppm should will be revoked. 

Pending Tolerance Petitions:

The following petitions for the establishment of tolerances for residues

of paraquat in/on various commodities and applications for amended use

patterns are pending:

PP#5F01625/5H05088: The petition requests the registration of an

additional harvest-aid use for field corn and requests the following tolerances: 

popcorn at 0.05 ppm; corn grain at 0.05 ppm; corn, fresh (inc. sweet) at 0.05

ppm; corn forage at 3.0 ppm; corn fodder at 10.0 ppm; and corn flour at 0.1

ppm. This petition is currently in reject status because of several issues

including the need to submit a revised Section F and a full set of label

directions for popcorn.

PP#5F1639: The petition requests label use amendments for alfalfa,

clover, other legumes, and pasture and rangeland reseeding; the petition also

proposes revised tolerances for non-grass animal feeds group forage and hay,

alfalfa meal, and grass forage, fodder, and hay. This petition is currently in
102

reject status because of several issues including the need for adequate field trial

data in support of petitioner-proposed changes in labeling.

PP#1E4019: The petition requests for the establishment of a tolerance

for artichokes. This petition is currently in reject status because additional field

trial data are required to support the proposed 1-day PHI.
103

Tolerance Reassessment Summary for Paraquat Dichloride

Commodity (ppm) (ppm) [Correct Commodity Definition]

Current Tolerance

Tolerance Reassessment Comment/

Tolerances Listed Under 40 CFR 180.205(a):

Acerola 0.05 0.05

Alfalfa 5 Will be replaced

with crop group

tolerances for

forage at 75 ppm

and hay at 210

ppm

Crop group tolerance proposals must be made in conjunction

with required label revisions.

[Non-grass animal feeds group, forage ] and [Non-grass

animal feeds group, hay ]

Birdsfoot trefoil 5

Clover 5

Almond hulls 0.5 0.5 [Almond, hulls ]

Apples 0.05(N) -- A crop group tolerance of 0.05 ppm for [Pome fruits group ]

Pears 0.05(N) will be established. --

Apricots 0.05(N) --

Following the required label revisions, a crop group tolerance

of 0.05 ppm for the [Stone fruits group ] will be established.

Cherries 0.05(N) --

Nectarines 0.05(N) --

Peaches 0.05(N) --

Plums (fresh prunes) 0.05(N) --

Asparagus 0.5 0.5

Avocados 0.05(N) 0.05

Bananas 0.05(N) 0.05

Barley grain 0.05(N) 0.05 [Barley, grain ]

Bean straw 30.0 Revoke [Beans, straw]

Beans, dry 0.3 0.3

Beans, forage 0.1 0.1 [Cowpea, forage ]

Beans, hay 0.4 0.4 [Cowpea, hay ]

Beans, lima (succulent) 0.05 0.05 [Beans, lima, succulent ]

Beans, snap (succulent) 0.05 0.05 [Beans, snap, succulent ]

Beets, sugar 0.5 0.5 [Sugar beets, roots ]

Beets, sugar (tops) 0.5 0.05

[Sugar beets, tops ] Residues were ND (<0.025 ppm) on all

treated sugar beet top samples from field trials conducted at a

1X rate.

Broccoli 0.05 --

A crop group tolerance of 0.05 ppm for Brassica (cole) leafy

vegetables group will be established.

Cabbage 0.05 --

Cauliflower 0.05 --

Chinese cabbage 0.05 --

Collards 0.05 --

Cacao beans 0.05 0.05

Carrots 0.05 0.05
Commodity (ppm) (ppm) [Correct Commodity Definition]

Current Tolerance

Tolerance Reassessment Comment/

104

Cattle, fat 0.05 0.05

Cattle, kidney 0.3 0.5 CODEX Harmonization

Cattle, meat 0.05 0.05

Cattle, mbyp (except kidney) 0.05 0.05

Citrus fruit 0.05(N) 0.05 [Citrus fruit group ]

Coffee beans 0.05(N) 0.05 [Coffee, bean, green ]

Corn, fresh (inc sweet corn)

(K+CWHR) 0.05(N) 0.05 [Corn, sweet (K + CWHR) ]

Corn fodder 0.05(N) 6

The following tolerances will be established to distinguish the

fodder of various corn types:

[Corn, field, stover at 6 ppm],

[Corn, pop, stover at 6 ppm], and

[Corn, sweet, stover at 6 ppm].

Corn forage 0.05(N) 3

The following tolerances will be established to distinguish the

forage of various corn types:

[Corn, field, forage at 3 ppm], and

[Corn, sweet, forage at 3 ppm].

Corn grain 0.05(N) 0.05

Since paraquat use as a harvest aid in TN (TN940007) has

recently be approved, the Agency will require that additional

field trials be conducted by the registrant to support this use. 

[Corn, field, grain ]

Cottonseed 0.5 0.5 [Cotton, seed ]

Cucurbits 0.05 0.05 [Cucurbit vegetables group ]

Eggs 0.01(N) 0.01 [Egg]

Figs 0.05(N) 0.05 [Fig]

Goats, fat 0.05 0.05 [Goat, fat]

Goats, kidney 0.3 0.5 CODEX Harmonization ; [Goat, kidney ]

Goats, meat 0.05 0.05 [Goat, meat]

Goats, mbyp (except kidney) 0.05 0.05 [Goat,mbyp (except kidney)]

Grass, pasture 5

Will be replaced

with crop group

tolerances for

grass forage at

90 ppm and grass

hay at 40 ppm

Crop group tolerance proposals must be made in conjunction

with required label revisions.

[Grass, forage ], 

and [Grass, hay ]

Grass, range 5

Guar beans 0.5 0.5

Guava 0.05(N) 0.05 [Guava]

Hogs, fat 0.05 0.05 [Hog, fat]

Hogs, kidney 0.3 0.5 CODEX Harmonization ; [Hog, kidney]

Hogs, meat 0.05 0.05 [Hog, meat]

Hogs, mbyp (except kidney) 0.05 0.05 [Hog,mbyp (except kidney)]
Commodity (ppm) (ppm) [Correct Commodity Definition]

Current Tolerance

Tolerance Reassessment Comment/

105

Hops, fresh 0.1 Revoke These items are not recognized RACs of hops (Table I, OPPTS

Hop vines 0.5 Revoke 860.1000).

Horses, fat 0.05 0.05 [Horse, fat]

Horses, kidney 0.3 0.5 CODEX Harmonization; [Horse, kidney]

Horses, meat 0.05 0.05 [Horse, meat ]

Horses, mbyp (except kidney) 0.05 0.05 [Horse, mbyp (except kidney)]

Kiwifruit 0.05 0.05 [Kiwifruit]

Lentils 0.3 0.3 Recently established (60 FR 27421, 5/24/95) in conjunction

with PP#4E4359.

Lentil, forage 0.1 Revoke with PP#4E4359; however, this item is no longer recognized as

Recently established (60 FR 27421, 5/24/95) in conjunction

a RAC of lentils [Table I (OPPTS 860.1000)].

Lentil, hay 0.4 Revoke with PP#4E4359; however, this item is not a recognized RAC

Recently established (60 FR 27421, 5/24/95) in conjunction

of lentils [Table I (OPPTS 860.1000)].

Lettuce 0.05(N) 0.05

Milk 0.01(N) 0.01

Mint, hay 0.5 Revoke [Peppermint, tops] [Spearmint, tops]

Nuts 0.05(N) 0.05 [Tree nuts group ]

Oat grain 0.05(N) Revoke Registrant has indicated that they do not wish to support use of

paraquat on oats. 

Olives 0.05(N) 0.05 [Olive]

Onions, dry bulb 0.05 0.05 [Onion, dry bulb (only) ]

Onions, green 0.05 0.05 [Onion, green ]

Papayas 0.05(N) 0.05 [Papaya]

Passion fruit 0.2 0.2

Peanuts 0.05 0.05 [Peanut, nutmeat ]

Peanut, hay 0.5 0.5 [Peanut, hay ]

Peanut, hulls 0.2 0.2 [Peanut, hulls ]

Peanut, vines 0.5 Revoke This item is not a recognized RAC of peanuts (Table I OPPTS

860.1000).

Peas (succulent) 0.05 0.05 [Pea, succulent ]

Peas, forage 0.2 0.2 [Pea, field, vines ]

Peas, hay 0.8 0.8 [Pea, field, hay ]

Pineapples 0.05(N) 0.05 [Pineapple ]

Pistachio nuts 0.05 0.05 [Pistachio]

Potatoes 0.5 0.5 [Potato]

Poultry, fat 0.01(N) Revoke

40 CFR 180.6(a)(3)
Commodity (ppm) (ppm) [Correct Commodity Definition]

Current Tolerance

Tolerance Reassessment Comment/

106

Poultry, meat 0.01(N) Revoke

Poultry, mbyp 0.01(N) Revoke

Rhubarb 0.05(N) 0.05

Rice grain 0.05 0.05

Recently established (60 FR 7457, 2/8/95) in conjunction with

PP#5F03188.

[Rice, grain ]

Rice straw 0.06 0.06

Recently established (60 FR 7457, 2/8/95) in conjunction with

PP#5F03188.

[Rice, straw]

Rye grain 0.05(N) Revoke There are no registered uses of paraquat on rye.

Safflower seed 0.05(N) 0.05 [Safflower, seed ]

Sheep, fat 0.05 0.05

Sheep, kidney 0.3 0.5 CODEX Harmonization

Sheep, meat 0.05 0.05

Sheep, mbyp (except kidney) 0.05 0.05

Small fruit 0.05(N) 0.05 [Berries group ]

Sorghum forage 0.05(N) 0.1

The reassessed tolerance is contingent on a required proposal to

establish a PHI of 20 days. 

[Sorghum, grain, forage ]

Sorghum grain 0.05(N) 0.05

The reassessed tolerance is contingent on a required proposal to

establish a PHI of 48 days. 

[Sorghum, grain, grain ]

Soybeans 0.05(N) 0.25 Available data indicate current tolerance is too low.

Soybean forage 0.05(N) 0.03

This tolerance is based on preemergence use. Restrictions exist

against the grazing or harvesting for hay following

postemergence or harvest aid use. 

[Soybeans, forage ]

Strawberries 0.25 0.25 [Strawberry ]

Sugarcane 0.5(N) 0.5

Sunflower seeds 2 2 [Sunflower, seed ]

Turnips (roots) 0.05 0.05 [Turnip, roots ]

Turnips (tops) 0.05 0.05 [Turnip, tops ]

Vegetables, fruiting 0.05 0.05 [Vegetables, fruiting (exc. cucurbits) group ]

Wheat grain 0.05(N) 0.05 [Wheat, grain ]

Tolerances That Will Be Established or Need To Be Proposed Under 40 CFR §180.205(a)

Aspirated Grain Fraction -- TBD soybean and corn aspirated grain fraction study, which have a

The tolerance will be based on the results from the higher of the

been required by the Agency.

Barley, hay -- TBD a
Commodity (ppm) (ppm) [Correct Commodity Definition]

Current Tolerance

Tolerance Reassessment Comment/

107

Barley, straw -- 1

Corn, field, flour -- 0.1

Corn, pop, grain -- 0.05

Cotton, gin byproducts -- TBD a

Cranberry -- 0.05 Cranberry, grape and strawberry have been moved from the old

"Small Fruits and Berries" crop grouping to the

Grape "Miscellaneous" crop grouping. -- 0.05

Grape, juice -- TBD a

Pineapple, process residue -- 0.25

Raisins -- TBD a

Soybeans, hay -- 0.05

Soybeans, hull -- 2

Sugarcane, molasses -- 3

Taro foliage -- TBD is no longer permitted. Taro foliage is no longer considered to a

A restriction against the use of treated foliage for food purposes

be an animal feed item. 

Wheat, forage -- 0.5

Wheat, hay -- TBD a

Wheat, straw -- 1

Tolerances Listed Under 40 CFR 180.205(b):

Cassava 0.05 0.05 [Cassava (manioc) ]

Pigeon peas 0.05 0.05

Taniers 0.05 0.05 [Tanier]

Taro (corms) 0.1 0.1 [Taro, corm]

Tyfon 0.05 0.05

Yams 0.05 0.05 [Yam]

Tolerances Listed Under 40 CFR 185.4700:

Dried hops 0.2 0.5

In consideration of the designation of dried hops as a RAC and

not a processed feed commodity, the entry in 40 CFR

§185.4700 for dried hops will be transferred to 40 CFR

§180.205(a).

[Hops, cones, dried ]

Tolerances Listed Under 40 CFR 186.4700:

Mint, hay, spent 3.0 Revoke No longer listed as a Table I (8/96) feed item.

Sunflower; seed hulls 6.0 Revoke No longer listed in Table I.
108

TBD = To be determined. Assessment or reassessment of tolerance(s) cannot be made at this time because additional data are a

required.

a. CODEX Harmonization

The Codex Alimentarius Commission has established several

maximum residue limits (MRLs) for paraquat residues in various

commodities (see Guide to Codex Maximum Limits For Pesticide

Residues, Part 2, FAO CX/PR, 4/91). The Codex and U.S. tolerance are

in harmony with respect to MRL/tolerance expression; both regulate the

parent paraquat only. A comparison of the Codex MRLs and the

corresponding reassessed U.S. tolerances is presented in the Table

below.

The following conclusions can be made regarding efforts to

harmonize the U.S. tolerances with the Codex MRLs with respect to

MRL/tolerance level:

• Compatibility between U.S. tolerances and Codex MRLs exists

for eggs, passion fruit, sunflower seed, and vegetables [including

beans (succulent), Brassica (cole) leafy vegetables group,

carrots, cassava, corn (sweet), cucurbits, fruiting vegetables,

lettuce, onions (dry bulb and green), peas (succulent), pigeon

peas, turnips (roots and tops), and yams], milk and ruminant

tissue, and poultry eggs.

• Incompatibilities of U.S. tolerances and Codex MRLs on the

following raw plant commodities remain because of differences

in agricultural practices: cottonseed, dry hops, maize, olives,

potatoes, rice, sorghum, and dry soya bean.

• No questions of compatibility exist with respect to commodities

where: (i) no Codex MRLs have been established but U.S.

tolerances exist; or (ii) Codex MRLs have been established but

U.S. tolerances do not exist.

Codex MRLs and applicable U.S. tolerances. Recommendations for compatibility are based on

conclusions following reassessment of U.S. tolerances (see the tolerance reassement summary table

above).

Codex U.S. Tolerance

Commodity (As Defined) MRL (mg/kg) (ppm) Recommendation And Comments a

Cattle, kidney 0.5 0.5 Compatability exists.

Cotton seed 0.2 0.5
Codex U.S. Tolerance

109

Cotton seed oil, edible 0.05 (*) --

Edible offal of cattle, pig, Compatability exists

and sheep (except as 0.05 (*) 0.05

otherwise listed)

Egg 0.01 (*) 0.01 Compatibility exists.

Hop, dry 0.2 0.5

Maize 0.1 0.05

Meat of cattle, pig, and Compatability exists

sheep 0.05 (*) 0.05

Milk 0.01 (*) 0.01

Olive 1 0.05

Passion fruit 0.2 0.2 Compatibility exists.

Pig, kidney 0.5 0.5 Compatability exists

Potato 0.2 0.5

Rice 10 0.05

Rice, polished 0.5 --

Sheep, kidney 0.5 0.5 Compatability exists

Sorghum 0.5 0.05

Soya bean (dry) 0.1 0.25 b

Sunflower seed 2 2 Compatibility exists.

Sunflower seed oil, crude 0.05 (*) --

Sunflower seed oil, edible 0.05 (*) --

Vegetables 0.05 (*) 0.05

Compatibility exists for many vegetables including beans (succulent),

Brassica (cole) leafy vegetables group, carrots, cassava, cucurbits,

fruiting vegetables, lettuce, onions (dry bulb and green), peas

(succulent), rhubarbs, turnips (roots and tops), and yams.

a All paraquat dichloride MRLs are final (CXL) except on soya bean (dry). Asterisk (*) signifies that the MRL was established at or about the limit of detection.

b A proposal to establish an MRL of 0.2 mg/kg for soya bean (dry) reached Step 6. However, during the 23rd Session of the CCPR (4/91), the Committee decided to withdraw the

proposal and the CXL for soyabean (dry) at 0.1 mg/kg was retained.

3. Tolerance Revocations and Import Tolerances

As part of the Agency’s reregistration eligibility decision for paraquat dichloride

several food/feed uses will be cancelled/voluntarily cancelled. Once a pesticide use is

no longer registered in the United States, the related pesticide residue tolerance and/or

food/feed additive regulation generally is no longer needed. It is the Agency’s's policy

to propose revocation of a tolerance, and/or food/feed additive regulation, following the

deletion of a related food use from a registration, or following the cancellation of a

related food-use registration. 

The Agency recognizes, however, that interested parties may want to retain a

tolerance and/or food/feed additive regulation in the absence of a U.S. registration, to

allow legal importation of food into the U.S. To assure that all food marketed in the

U.S. is safe, under FFDCA, the Agency requires the same technical chemistry and

toxicology data for such import tolerances (tolerances without related U.S. registrations)

as are required to support U.S. food use registrations and any resulting tolerances. See

40 CFR Part 158 for the Agency’s data requirements to support domestic use of a

pesticide and establishment and maintenance of a tolerance and/or food/feed regulation. 
110

In addition, the Agency requires residue chemistry data (crop field trials) that are

representative of growing conditions in exporting countries in the same manner that the

Agency requires representative residue chemistry data from different U.S. regions to

support domestic use of the pesticide and the tolerance and/or regulation. Additional

guidance on the Agency's import tolerance policy will be published in an upcoming

Federal Register Notice.

Parties interested in supporting an existing paraquat tolerance as an import tolerance

should ensure that all of the data noted above are available to the Agency during its

further assessments of existing tolerances and regulations, so that the Agency may

determine whether maintenance of the tolerance and/or regulation would be protective

of the public health.

4. Summary of Risk Management Decisions

a. Human Health

(1) Dietary

Acute Dietary

The Agency has determined that a risk assessment for acute dietary (1 day)

risk is not necessary, since no data presented/available suggest a need for an acute

dietary endpoint.

Chronic Dietary (including cancer)

The Agency has evaluated the chronic dietary risk associated with the use of

paraquat based on established and proposed tolerance levels and assuming 100%

of each crop is treated. The RfD was established at 0.0045 mg/kg/day (expressed

as paraquat cation) based upon a chronic toxicity (1 year) study in dogs with a

NOEL of 15ppm (.45 mg/kg/day) and an uncertainty factor (UF) of 100. The

chronic dietary risk is considered to be minimal. The chronic exposure analysis

results in a TMRC where the RfD was not exceeded for any of the 22 populations

subgroups analyzed. The chronic dietary exposure using the existing tolerances

result in a Theoretical Maximum Residue Contribution (TMRC) which is 10% of

the RfD for the U.S. general population. The subpopulation with the highest

exposure is non-nursing infants (<1 year old). This subpopulation’s TMRC

utilizes 31% of the RfD. The Agency considers exposures which utilize 100% or

less of the RfD to be adequately protective.

(2) Worker (Mixer/Loader/Applicator)
111

Acute (Short-Term) and Intermediate Term

The Toxicological Endpoint Selection Committee (TES) indicated

inhalation endpoints should be used for risk assessment only in cases in which the

spray particles are of a respirable size. This endpoint was based on the NOEL and

LOEL for subchronic (3 weeks) inhalation toxicity, for both sexes, of 0.01 ug/L

and 0.10 ug/L, respectively, expressed as paraquat cation. The Agency decided

that particles used in agricultural practices (400 to 800 um) are well beyond the

resipirable range and therefore there is no need for this endpoint. 

The Agency has determined that there is a potential dermal exposure to

pesticide handlers. Therefore, for all other use scenarios (such as agricultural

applications), a "dermal endpoint" is used: NOEL of 3 mg/kg/day, expressed as

paraquat cation, based on maternal toxicity effects: unscheduled deaths, thin and

hunched appearance, decreased body weight gain, and histological changes in the

lungs and kidneys of the nonsurvivors. Exposure by the dermal route, obtained by

extrapolating data (NOEL) from a combination of two rat developmental toxicity

studies and correcting for dermal absorption (0.3%), is appropriate for short term

occupational and residential exposure. (MRIDs 00113714, 43964701 and

00153439). The rat developmental toxicity study was selected over the rabbit 21-

day dermal study because the Toxicology Endpoint Selection Committee (TES)

generally looks for systemic toxicity endpoints. The only biologically significant

endpoint observed in the 21-day dermal study was dermal irritation which is not

considered to be a systemic effect. Therefore, the NOEL for developmental

effects from the rat developmental toxicity study was selected as the endpoint of

choice. 

The MOEs for short and intermediate-term occupational exposure dermal

effects to paraquat are greater than 100 for all the exposure scenarios considered

except for backpack sprayer for applicators and low pressure sprayer (resin

soaking) for mixer/loader/applicators. For applicators using the backpack sprayer

the MOE for dermal exposure is 31 and for the mixer/loader/applicator using the

low pressure sprayer (resin soaking) the MOE for dermal exposure is 36. These

MOES assume the use of long pants and long-sleeve shirts (no gloves). However,

with the addition of gloves, the MOE for backpack spayer is raised to 64 and the

MOE for the mixer/loader/applicator using the low pressure sprayer (resin

soaking) is raised to 910. Since the backpack spayer scenario MOE is still below

100, even with the addition of gloves, the Agency and the registrant have agreed

to the following requirements to mitigate (bring the unsatisfactory MOE up to100)

the remaining risk :
112

 Modifying all paraquat labels to specify that the maximum backpack

applications (non-spot) be 0.625 cation/A with a minimum volume of 20

gallons per Acre.

 This mitigation for backpack non-spot application reduces the finish

spray dilution concentration of paraquat in the spray tank to approximately

0.4% w/w of cation.

Post-Application

Based on the postapplication biological monitoring study the Agency has

determined that a 12 hour restricted-entry interval is adequate for the uses of

paraquat for preemergent or early-season weed control and weed control for

orchard and vegetable crops where the spray is directed solely at the weeds (not

broadcast over the entire crop area). A 24-hour restricted-entry interval is

required for desiccation and harvest aid applications of paraquat since the Agency

concludes such uses result in exposures to workers of a greater degree. These

12/24 hour post-application REI's measures should be sufficient to mitigate the

potential exposure to workers.

b. Environmental

(1) Avian

Acute

The Agency has evaluated data to determine the acute effects of paraquat

dichloride to birds. At the use rate of 1.49 lbs cation/A the risk quotients were

determined to be more than 0.5, the LOC for presuming adverse effects to avian

species. At the proposed mitigation rate of 1.0 cation/A, restricted use and

endangered species LOCs will still be exceeded. However, because of the

environmental fate characteristics of paraquat, the risk to birds only exists shortly

after application. Once the applied paraquat has dried its risk is greatly reduced. 

Therefore the Agency concludes the registered uses of paraquat dichloride are not

expected to pose significant acute risk to avian species.

Chronic

The Agency has evaluated data on the chronic effects of paraquat to birds. 

The chronic risk quotients for birds range from 0.80 - 12.80 for the 1.6 lb cation/A

rate and 0.5 - 8.00 for the 1.0 lb cation/A rate. Normally these high LOCs would

indicate a chonic risk to birds. However, as noted above, the environmental fate
113

data indicate that paraquat once applied and dried is not expected to pose a risk. 

Therefore, the registered uses of paraquat dichloride are not expected to pose a

significant chronic risk to avian species. 

Although a chronic risk is not expected, the Agency was concerned that

direct use of paraquat dichloride may affect avian reproduction. However, after

reviewing additional information regarding the uses of paraquat (Row Crop,

Tree/Vine/Fruit, Vegetable, Alfalfa, and Harvest-Aid uses) the Agency has

concluded that the greater risk to eggs within a treated field is from subsequent

agricultural practices such as mowing, bailing, fungicide and insecticide spraying,

irrigation, etc.. Regarding effects to off-field nesting areas, assuming 5% drift, the

resulting “in egg” concentrations of paraquat are not expected to be sufficient to

cause significant mortality or reductions in hatchability and growth. 

(2) Mammals

Acute

Even though some of the risk quotients for paraquat dichloride exceed high

acute risk for the 1.6 lb cation/A and 1.0 cation/A application rate, the Agency

concludes that the use of paraquat will not harm mammals, including endangered

species through acute toxicity since it becomes biologically unavailable once it

dries.

Chronic

The Agency has evaluated data to determine the chronic effects of paraquat

dichloride to mammals. At the use rate of 1.6 lb cation/A and 1.0 lb cation/A

some of the risk quotients were determined to be more than 1, the LOC for

presuming chronic risk to mammals. However, environmental fate data indicate

that paraquat once applied and dried is not expected to pose risk. Likewise, the

risk mitigation measures (reduced application rates) proposed above for birds

should also reduce the exposure of paraquat to mammals.

(3) Insects

Paraquat is practically non-toxic to honeybees and for the most part paraquat

will be used at times when honey bees will not be active in the field. Therefore,

the use of paraquat is not likely to affect honey bees.
114

(4) Freshwater Fish

No acute or chronic LOCs have been exceeded for freshwater fish. 

Therefore, the use of paraquat dichloride is not likely to adversely affect

freshwater fish.

(5) Aquatic invertebrates

No acute or chronic LOCs have been exceeded for freshwater invertebrates. 

Therefore, the use of paraquat dichloride is not likely to adversely affect

freshwater invertebrates.

(6) Estuarine and Marine Organisms

No acute LOCs have been exceeded for estuarine and marine organisms.

Therefore, the use of paraquat dichloride is unlikely to adversely impact

estuarine/marine endangered or non-endangered species. Data were not available

to assess the chronic risk to estuarine and marine organisms. Due to paraquat

dichloride's strong adsorption to soil which makes it biologically unavailable,

chronic testing on estuarine and marine organisms is not required.

(7) Nontarget Plants (Terrestrial, Semi-Aquatic, and Aquatic)

The Agency has evaluated data which indicate that LOCs are exceeded for

terrestrial, and semi-aquatic plants. As was stated previously, paraquat dichloride

binds strongly to soil and it is therefore not expected to affect non-target terrestrial

and semi-aquatic plants as a result of runoff. Rather the risk of paraquat to nontarget terrestrial and semi-aquatic plants is expected to come only as a result of

drift during application. Depending on the application method and application

rates, the risk quotients for non-endangered terrestrial and semi-aquatic plants

range from 0.0 -6.15 and the endangered species risk quotients range from 0.0 -

20.0. Therefore, drift from paraquat may adversely affect nontarget terrestrial and

semi-aquatic plants, including endangered species.

At paraquat's lowest application rate of 0.07 lb cation/A, no risk to

endangered terrestrial and semi-aquatic plants is expected. In order to mitigate the

upper end risk quotients, the registrant has agreed to lower the maximum use rate

to 1 lb cation/A. However, aerial application of paraquat at the 1.0 lb cation/A

rate is still expected to pose some risk to non-target terrestrial and semi-aquatic

plants due to drift, but ground application at the same rate is not expected to pose

risk.
115

To provide additional protection to non-target terrestrial and semi-aquatic

plants the following mitigation measures are being required:

 Aerial applications must include the most current spray drift language (see

description under Actions Required by Registrants)

 All paraquat products must place a statement in the “Environmental

Hazard”section of the label that warns the user about possible adverse effects to

non-target and semi-aquatic plants due to drift. (See section V for the specific

labeling statement). 

(8) Endangered Species

The Agency has concerns about the exposure of threatened and endangered

plant and animal species to paraquat as discussed above in the science assessment

chapter. Endangered species LOCs have been exceeded for chronic effects on

birds, small mammals and for acute effects on semi-aquatic and terrestrial plants. 

The risk for birds and small mammals only exist until the paraquat dichloride

residues dries (or becomes bound). 

Currently, the Agency is developing a program ("The Endangered Species

Protection Program") to identify all pesticides whose use may cause adverse

impacts on endangered and threatened species and to implement mitigation

measures that will eliminate the adverse impacts. The program would require use

restrictions to protect endangered and threatened species at the county level. 

Consultations with the Fish and Wildlife Service may be necessary to assess risks

to newly listed species or from proposed new uses. In the future, the Agency

plans to publish a description of the Endangered Species Program in the Federal

Register and have available voluntary county-specific bulletins. Because the

Agency is taking this approach for protecting endangered and threatened species,

it is not imposing label modifications at this time through the RED. Rather, any

requirements for product use modifications will occur in the future under the

Endangered Species Protection Program.

(9) Water Resources

Although there were detections of paraquat in drinking water wells from two

states cited in the Pesticides in Groundwater Database, these detections are not

considered to be representative of normal paraquat use. Paraquat dichloride binds

so strongly to soil clay particles that it did not leach from the surface in the

terrestrial field dissipation studies. Therefore, the Agency concludes there is no

concern for paraquat contaminating groundwater from normal use patterns. 
116

(10) Restricted Use Classification

All paraquat products are currently classified as pesticides (February 9,

1978, 43 FR 5782). Originally, this restriction was based on acute toxicity and the

potential for intentional or inadvertent exposure. More recent acute data indicate

lower toxicity for all routes of exposure except inhalation (a new inhalation study

was not submitted). However, the spray droplets of paraquat from all currently

registered products are not of respirable size and inhalation is not an exposure

route of concern. Notwithstanding the lack of acute toxicity concerns, the Agency

is maintaining the Restricted Use classification for all paraquat products based on 

the severity of effects from paraquat oral ingestion and inappropriate dermal

exposure, limited effectiveness of therapeutic treatment after exposure and in

order to continue to deter misuse of this product.

5. Occupational/Residential Labeling Rationale

The Worker Protection Standard (WPS)

Scope of the WPS

The 1992 Worker Protection Standard for Agricultural Pesticides (WPS) established

certain worker-protection requirements (personal protective equipment, restricted-entry

intervals, etc.) to be specified on the label of all products that contain uses within the

scope of the WPS. Uses within the scope of the WPS include all commercial (nonhomeowner) and research uses on farms, forests, nurseries, and greenhouses to produce

agricultural plants (including food, feed, and fiber plants, trees, turf grass, flowers,

shrubs, ornamentals, and seedlings). Uses within scope include not only uses on plants,

but also uses on the soil or planting medium the plants are (or will be) grown in. 

At this time some of the registered uses of paraquat are within the scope of the

Worker Protection Standard for Agricultural Pesticides (WPS) and some uses are

outside the scope of the WPS. Some examples of uses that are outside the scope of the

WPS include use: 

on pastures or rangelands,

on plants that are in ornamental gardens, parks, golf courses, and public or private

lawns and grounds and that are intended only for decorative or environmental

benefit. 

in a manner not directly related to the production of agricultural plants, including,

for example, control of vegetation along rights-of-way and in other non-crop

areas. 
117

Compliance With the WPS

Any product whose labeling can be reasonably interpreted to permit use in the

production of an agricultural plant on any farm, forest, nursery, or greenhouse must

comply with the labeling requirements of PR Notice 93-7, "Labeling Revisions

Required by the Worker Protection Standard (WPS)," and PR Notice 93-11,

"Supplemental Guidance for PR Notice 93-7," which reflect the requirements of the

Agency’s labeling regulations for worker protection statements (40 CFR part 156,

subpart K). These labeling revisions are necessary to implement the Worker Protection

Standard for Agricultural Pesticides (40 CFR part 170) and must be completed in

accordance with, and within the deadlines specified in, PR Notices 93-7 and 93-11.

Unless otherwise specifically directed in this RED, all statements required by PR

Notices 93-7 and 93-11 are to be on the product label exactly as instructed in those

notices.

After April 21, 1994, except as otherwise provided in PR Notices 93-7 and 93-11,

the labeling of all products within the scope of those notices must meet the

requirements of the notices when the products are distributed or sold by the

primary registrant or any supplementally registered distributor.

After October 23, 1995, except as otherwise provided in PR Notices 93-7 and

93-11, the labeling of all products within the scope of those notices must meet the

requirements of the notices when the products are distributed or sold by any

person.

Personal Protective Equipment/Engineering Controls for Handlers 

For each end-use product, PPE requirements for pesticide handlers are set during

reregistration in one of two ways: 

1. If the Agency determines that no regulatory action must be taken as the result of the

acute effects or other adverse effects of an active ingredient, the PPE for pesticide

handlers will be based on the acute toxicity of the end-use product. For occupationaluse products, PPE must be established using the process described in PR Notice 93-7 or

more recent EPA guidelines.

2. If the Agency determines that regulatory action on an active ingredient must be taken

as the result of very high acute toxicity or to certain other adverse effects, such as

allergic effects or delayed effects (cancer, developmental toxicity, reproductive effects,

etc.): 

In the RED for that active ingredient, the Agency may establish minimum or

"baseline" handler PPE requirements that pertain to all or most end-use products

containing that active ingredient.
118

These minimum PPE requirements must be compared with the PPE that would be

designated on the basis of the acute toxicity of the end-use product. 

The more stringent choice for each type of PPE (i.e., bodywear, hand protection,

footwear, eyewear, etc.) must be placed on the label of the end-use product.

Personal protective equipment requirements usually are set by specifying one or

more pre-established PPE units -- sets of items that are almost always required together. 

For example, if chemical-resistant gloves are required, then long-sleeve shirts, long

pants, socks, and shoes are assumed and are also included in the required minimum

attire. If the requirement is for two layers of body protection (coveralls over a long- or

short-sleeve shirt and long or short pants), the minimum must also include (for all

handlers) chemical-resistant footwear and chemical-resistant headgear for overhead

exposures and (for mixers, loaders, and persons cleaning equipment) chemical-resistant

aprons.

Occupational-Use Products

The Agency has determined that regulatory action regarding the establishment of

active-ingredient-based minimum PPE requirements for occupational handlers must be

taken for paraquat. Even though the MOE's were greater than 100 for occupational

mixers, loaders, and applicators (except backpack applicators and resin-soaking uses)

without personal protective equipment requirements beyond long-sleeve shirt, long

pants, shoes, and socks, the Agency notes the relatively significant epidemiological

evidence of poisonings from intentional/accidental oral ingestion and numerous nonsystemic skin and eye effects in California (see California Pesticide Illness Surveillance

System Data in OREB memo form J. Blondell, entitled: “Review of Paraquat Acute

Illness Data”, 12/5/95). These considerations have led to the determination that active

ingredient-based minimum PPE should be required for all occupational paraquat

handlers. 

Since potential handler exposure is similar for WPS and nonWPS uses, there is only

one set of active-ingredient-based minimum (baseline) PPE requirements for all

occupational uses of paraquat (specified in Section V). These requirements must be

followed in the labeling of all paraquat end-use products intended primarily for

occupational use.

Homeowner-Use Products

There are no registered homeowner-use products.

Post-Application/Entry Restrictions
119

Occupational-Use Products (WPS Uses)

Restricted-Entry Interval:

Under the Worker Protection Standard (WPS), interim restricted-entry intervals

(REI's) for all uses within the scope of the WPS are based on the acute toxicity of the

active ingredient. The toxicity categories of the active ingredient for acute dermal

toxicity, eye irritation potential, and skin irritation potential are used to determine the

interim WPS REI. If one or more of the three acute toxicity effects are in toxicity

category I, the interim WPS REI is established at 48 hours. If none of the acute toxicity

effects are in category I, but one or more of the three is classified as category II, the

interim WPS REI is established at 24 hours. If none of the three acute toxicity effects

are in category I or II, the interim WPS REI is established at 12 hours. A 48-hour REI is

increased to 72 hours when an organophosphate pesticide is applied outdoors in arid

areas. In addition, the WPS specifically retains two types of REI's established by the

Agency prior to the promulgation of the WPS: (1) product-specific REI's established on

the basis of adequate data, and (2) interim REI's that are longer than those that would be

established under the WPS.

During the reregistration process, the Agency considers all relevant product-specific

information to decide whether there is reason to shorten or lengthen the previously

established REI. 

During the reregistration process, the Agency determined that the restricted-entry

interval (REI) for all occupational-use products that contain paraquat and are within the

scope of the Worker Protection Standard for Agricultural Pesticides (WPS) should be

12 hours for preemergence and directed-spraying uses and 24 hours for desiccation and

harvesting uses.

Early-Entry PPE:

The WPS establishes very specific restrictions on entry by workers to areas that

remain under a restricted-entry interval, if the entry involves contact with treated

surfaces. Among those restrictions are a prohibition of routine entry to perform hand

labor tasks and a requirement that personal protective equipment be worn. Under the

WPS, these personal protective equipment requirements for persons who must enter

areas that remain under a restricted-entry interval are based on the acute toxicity

category of the active ingredient. 

During the reregistration process, the Agency considers all relevant product-specific

information to decide whether there is reason to set personal protective equipment

requirements that differ from those set through the WPS. 
120

The RED requirements for early-entry personal protective equipment are set in one of

two ways:

1. If the Agency determines that no regulatory action must be taken as the result of

the acute effects or other adverse effects of an active ingredient, it establishes the

early-entry PPE requirements on the basis of the acute dermal toxicity category,

skin irritation potential category, and eye irritation potential category of the active

ingredient. 

2. If theAgency determines that regulatory action on an active ingredient must be

taken as the result of very high acute toxicity or to certain other adverse effects,

such as allergic effects or delayed effects (cancer, developmental toxicity,

reproductive effects), it may establish early-entry PPE requirements that are more

stringent than would be established otherwise.

The Agency is establishing PPE for dermal protection on the basis of the acute

toxicity of the active ingredient. Paraquat is classified as toxicity category III for acute

dermal toxicity. Since paraquat is classified as category II for eye irritation potential,

protective eyewear is required. 

WPS Notification Statement:

Under the WPS, the labels of some pesticide products must require employers to

notify workers about pesticide-treated areas orally as well as by posting of the treated

areas. The reregistration process also may decide that a product requires this type of

"double notification."

Based on the acute toxicity of the active ingredient, the Agency is not requiring

double notification.

Occupational-Use Products (NonWPS Uses)

 Since the Agency has concerns about post-application exposures to persons after

nonWPS occupational uses of paraquat, it is establishing entry restrictions for all

nonWPS occupational uses of paraquat end-use products. For specific requirements,

refer to Section V of this document.

Homeowner-Use Products

There are no registered homeowner-use products.
121

Other Labeling Requirements

The registrant has agreed to lower application rates and label changes for tree

injection. These changes are summarized in Section V. The Agency is also requiring

other use and safety information to be placed on the labeling of all end-use products

containing paraquat. For the specific labeling statements, refer to Section V of this

document.

V. ACTIONS REQUIRED OF REGISTRANTS

This section specifies the data requirements and responses necessary for the reregistration of

both manufacturing-use and end-use products.

A. Manufacturing-Use Products

1. Additional Generic Data Requirements

The generic data base supporting the reregistration of paraquat dichloride for the

above eligible uses has been reviewed and determined to be substantially complete. 

However, EPA is requiring data to establish tolerances for paraquat dichloride on taro

foliage, corn and soybean aspirated grain fractions, wheat and hay, cotton and gin

byproducts and processed grapes. The Agency is also requiring data to confirm that the

existing tolerance for field corn is adequate to cover the specialized use of paraquat as a

harvest aid. See the chart below for data requirements:

Guideline # Study Title

62-3 Analytical Methods (For the MP, EPA Reg. No. 10182-362)

171-3 Directions for Use

171-4(k) Magnitude of the Residue in Plants - Taro foliage

171-4(k) Mag. of the Res. in Plants - Soybean aspirated grain fractions

171-4(k) Mag. of the Res. in Plants - Corn, field, grain and aspirated grain

fractions

171-4(k) Mag. of the Res. in Plants - Wheat and hay*

171-4(k) Mag. of the Res. in Plants - Cotton, and gin byproducts

171-4(l) Mag. of the Res in Processed Food/Feed - Grapes

201-1 Droplet size spectrum

202-1 Drift field evaluation

* The registrant should refer to the 4/23/96 CBRS memorandum and cite the available data for wheat

straw.
122

 

2. Labeling Requirements for Manufacturing-Use Products

To remain in complaince with FIFRA, manufacturing use product (MP) labeling

must be revised to comply with all current EPA regulations, PR Notices and applicable

policies. The MP labeling must bear the following statement under Directions for Use:

"Only for formulation into an __________[fill blank with Insecticide, Herbicide or

the applicable term which describes the type of pesticide use(s)] for the following

use(s) __________ [fill blank only with those uses that are being supported by MP

registrant."

An MP registrant may, at his/her discretion, add one of the following statements to an

MP label under 

"Directions for Use" to permit the reformulation of the product for a specific use

or all additional uses supported by a formulator or user group:

(a) "This product may be used to formulate products for specific use(s) not listed

on the MP label if the formulator, user group, or grower has complied with

U.S. EPA submission requirements regarding support of such use(s)."

(b) "This product may be used to formulate products for any additional use(s) not

listed on the MP label if the formulator, user group, or grower has complied

with U.S. EPA submission requirements regarding support of such use(s)."

B. End-Use Products

1. Additional Product-Specific Data Requirements

Section 4(g)(2)(B) of FIFRA calls for the Agency to obtain any needed productspecific data regarding the pesticide after a determination of eligibility has been made. 

The product specific data requirements are listed in Appendix G, the Product Specific

Data Call-In Notice.

Registrants must review previous data submissions to ensure that they meet current

EPA acceptance criteria (Appendix F; Attachment E) and if not, commit to conduct new

studies. If a registrant believes that previously submitted data meet current testing

standards, then study MRID numbers should be cited according to the instructions in the

Requirement Status and Registrants Response Form provided for each product.

2. Labeling Requirements for End-Use Products
123

a. Application Rates and Label Deletions

In cooperation with the Agency the registrant has agreed to the following

application rates and label deletions:

 The maximum paraquat dichloride application rate for all products will be

lowered from 1.6 lb cation/A to 1.0 lb cation/A.

 For broadcast applications of paraquat with backpack sprayers, non-spot, the

application rate should not exceed 0.625 lb cation/A and the application volume

should be no less than 20 gallons per acre.

 The maximum application rate for spot spraying on all paraquat labels will be

no more than 0.0195 lbs cation/gallon.

 Delete the plastic acid bottle and the tree injection directions for use from the

resin soaking sections of all paraquat dichloride labels.

b. Hazard Statement

The following hazard statement must be placed in the “Environmental Hazard”

section of all paraquat labels to warn the user about possible adverse effects to nontarget terrestrial and semi-aquatic plants due to drift:

“Paraquat dichloride is toxic to nontarget crops and plants if off-target

movement occurs. Extreme care must be taken to ensure that off-target drift

is minimized to the greatest extent possible.”

c. PPE/Engineering Control Requirements for Pesticide Handlers

For sole-active-ingredient end-use products that contain paraquat, the product

labeling must be revised to adopt the handler personal protective

equipment/engineering control requirements set forth in this section. Any conflicting

PPE requirements on the current labeling must be removed. 

For multiple-active-ingredient end-use products that contain paraquat, the

handler personal protective equipment/engineering control requirements set forth in

this section must be compared to the requirements on the current labeling and the

more protective must be retained. For guidance on which requirements are

considered more protective, see PR Notice 93-7.
124

d. Products Intended Primarily for Occupational Use (WPS and nonWPS)

Minimum (Baseline) PPE/Engineering Control Requirements

Although the MOE's were greater than 100 for all but two scenarios (backpack

applicators and resin-soaking uses) without personal protective equipment

requirements beyond long-sleeve shirt, long pants, shoes and socks, the Agency

notes the relatively significant epidemiological evidence of poisonings from

intentional/accidental swallowing and numerous non-systemic skin and eye effects in

California (see OREB J. Blondell memo, 12/5/95). These considerations have led to

the Agency establishing the following minimum (baseline) PPE for all occupational

uses of paraquat end-use products:

"Mixers and loaders must wear:

--long-sleeved shirt and long pants,

--chemical-resistant gloves*, 

--shoes plus socks,

--chemical-resistant apron,

--face shield"

Although there is no direct evidence that occupational handlers have ever ingested

a lethal amount of paraquat from a splash or spill, the requirement for a face shield

for all mixers and loaders reflects the Agency’s particular concern about accidental

swallowing in case of a spill or splash back.

"Applicators and other handlers (other than mixers and loaders) must wear: 

--long-sleeved shirt and long pants, 

--chemical-resistant gloves*, 

--shoes plus socks"

* For the glove statement, use the statement established for paraquat through the

instructions in Supplement Three of PR Notice 93-7. 

Determining PPE Requirements for End-use Product Labels

The PPE that would be established on the basis of the acute toxicity category of

the end-use product must be compared to the active-ingredient-based minimum

(baseline) personal protective equipment specified above. The more protective PPE

must be placed on the product labeling. For guidance on which PPE is considered

more protective, see PR Notice 93-7.
125

Placement in Labeling

The personal protective equipment requirements must be placed on the end-use

product labeling in the location specified in PR Notice 93-7, and the format and

language of the PPE requirements must be the same as is specified in PR Notice 93-

7.

Products Intended Primarily for Occupational Use

There are no registered homeowner-use products

Entry Restrictions

For sole-active-ingredient end-use products that contain paraquat the product

labeling must be revised to adopt the entry restrictions set forth in this section. Any

conflicting entry restrictions on the current labeling must be removed. 

For multiple-active-ingredient end-use products that contain paraquat the entry

restrictions set forth in this section must be compared to the entry restrictions on the

current labeling and the more protective must be retained. A specific time period in

hours or days is considered more protective than "sprays have dried" or "dusts have

settled."

e. Products Intended Primarily for Occupational Use - Entry Restrictions and

Labeling

WPS Uses

Restricted-entry interval:

"For preplant or preemergence (broadcast or banded) applications, postemergence directed-spray applications, dormant-season applications, and

"between cutting" alfalfa applications: Do not enter or allow worker entry into

treated areas during the restricted entry interval (REI) of 12 hours."

"For harvest-aid and desiccation applications: Do not enter or allow worker entry

into treated areas during the restricted entry interval (REI) of 24 hours."

Early-entry personal protective equipment (PPE):

The PPE required for early entry is: 

-- coveralls,

-- chemical-resistant gloves*,

-- shoes plus socks,
126

-- protective eyewear.

* For the glove statement, use the statement established for paraquat through the

instructions in Supplement Three of PR Notice 93-7. 

WPS Notification Statement:

Not reqiured on label.

Placement in labeling:

The REI statements must be inserted into the Agricultural Use Requirements box as

required by Supplement Three of PR Notice 93-7. The PPE required for early entry

must be inserted into the standardized early-entry PPE statement required by

Supplement Three of PR Notice 93-7. The double notification statement must be

placed into the Agricultural Use Requirements box as required by Supplement Three

of PR Notice 93-7.

NonWPS uses

Entry restrictions:

The Agency is establishing the following entry restrictions for nonWPS

occupational uses of paraquat end-use products:

"Do not enter or allow others to enter the treated area until sprays have dried."

Placement in labeling:

If WPS uses are also on label -- Follow the instructions in PR Notice 93-7 for

establishing a Non-Agricultural Use Requirements box, and place the appropriate

nonWPS entry restrictions in that box.

If no WPS uses are on the label -- Place the appropriate nonWPS entry restrictions

in the Directions for Use, under the heading "Entry Restrictions."

Products Intended Primarily for Homeowner Use

Entry restrictions:

There are no registered homeowner-use products.
127

f. Other Labeling Requirements

Products Intended Primarily for Occupational Use

The Agency is requiring the following labeling statements to be located on all

end-use products containing paraquat that are intended primarily for occupational

use.

Application Restrictions

"Do not apply this product in a way that will contact workers or other

persons, either directly or through drift. Only protected handlers may be in

the area during application."

Engineering Controls

"When handlers use closed systems, enclosed cabs, or aircraft in a manner

that meets the requirements listed in the Worker Protection Standard (WPS)

for agricultural pesticides (40 CFR 170.240(d)(4-6), the handler PPE

requirements may be reduced or modified as specified in the WPS."

User Safety Requirements

"Discard clothing or other absorbent materials that have been drenched or heavily

contaminated with this product's concentrate. Do not reuse them."

"Follow manufacturer's instructions for cleaning/maintaining PPE. If no such

instructions for washable, use detergent and hot water. Keep and wash PPE

separately from other laundry."

"DO NOT USE AROUND HOMES, SCHOOLS, RECREATIONAL PARKS,

GOLF COURSES, OR PLAYGROUNDS"

User Safety Recommendations

"Users should wash hands before eating, drinking, chewing gum, using

tobacco, or using the toilet."

"Users should remove clothing immediately if pesticide gets inside. Then

wash thoroughly and put on clean clothing."
128

"Users should remove PPE immediately after handling this product. Wash

the outside of gloves before removing. As soon as possible, wash thoroughly

and change into clean clothing."

C. Spray Drift Labeling 

The following language must be placed on each paraquat product label that can be

applied aerially:

Avoiding spray drift at the application site is the responsibility of the applicator. The

interaction of many equipment-and-weather-related factors determine the potential

for spray drift. The applicator and the grower are responsible for considering all

these factors when making decisions.

The following drift management requirements must be followed to avoid off-target

drift movement from aerial applications to agricultural field crops. These

requirements do not apply to forestry applications, public health uses or to

applications using dry formulations.

1. The distance of the outer most nozzles on the boom must not exceed 3/4 the

length of the wingspan or rotor.

2. Nozzles must always point backward parallel with the air stream and never be

pointed downwards more than 45 degrees.

Where states have more stringent regulations, they shall be observed.

The applicator should be familiar with and take into account the information covered

in the Aerial Drift Reduction Advisory Information.

The following aerial drift reduction advisory information must be contained in the

product labeling:

[This section is advisory in nature and does not supersede the mandatory label

requirements.]

INFORMATION ON DROPLET SIZE

The most effective way to reduce drift potential is to apply large droplets. The best

drift management strategy is to apply the largest droplets that provide sufficient

coverage and control. Applying larger droplets reduces drift potential, but will not

prevent drift if applications are made improperly, or under unfavorable
129

environmental conditions (see Wind, Temperature and Humidity, and Temperature

Inversions).

CONTROLLING DROPLET SIZE

Volume - Use high flow rate nozzles to apply the highest practical spray volume. 

Nozzles with higher rated flows produce larger droplets.

Pressure - Do not exceed the nozzle manufacturer's recommended pressures. For

many nozzle types lower pressure produces larger droplets. When higher flow rates

are needed, use higher flow rate nozzles instead of increasing pressure.

Number of nozzles - Use the minimum number of nozzles that provide uniform

coverage.

Nozzle Orientation - Orienting nozzles so that the spray is released parallel to the

airstream produces larger droplets than other orientations and is the recommended

practice. Significant deflection from horizontal will reduce droplet size and increase

drift potential.

Nozzle Type - Use a nozzle type that is designed for the intended application. 

With most nozzle types, narrower spray angles produce larger droplets. Consider

using low-drift nozzles. Solid stream nozzles oriented straight back produce the

largest droplets and the lowest drift.

BOOM LENGTH

For some use patterns, reducing the effective boom length to less than 3/4 of the

wingspan or rotor length may further reduce drift without reducing swath width.

APPLICATION HEIGHT

Applications should not be made at a height greater than 10 feet above the top of the

largest plants unless a greater height is required for aircraft safety. Making

applications at the lowest height that is safe reduces exposure of droplets to

evaporation and wind.

SWATH ADJUSTMENT

When applications are made with a crosswind, the swath will be displaced

downwind. Therefore, on the up and downwind edges of the field, the applicator

must compensate for this displacement by adjusting the path of the aircraft upwind. 
130

Swath adjustment distance should increase, with increasing drift potential (higher

wind, smaller drops, etc.)

WIND

Drift potential is lowest between wind speeds of 2-10 mph. However, many factors,

including droplet size and equipment type determine drift potential at any given

speed. Application should be avoided below 2 mph due to variable wind direction

and high inversion potential. NOTE: Local terrain can influence wind patterns. 

Every applicator should be familiar with local wind patterns and how they affect

spray drift.

TEMPERATURE AND HUMIDITY

When making applications in low relative humidity, set up equipment to produce

larger droplets to compensate for evaporation. Droplet evaporation is most severe

when conditions are both hot and dry.

TEMPERATURE INVERSIONS

Applications should not occur during a temperature inversion because drift potential

is high. Temperature inversions restrict vertical air mixing, which causes small

suspended droplets to remain in a concentrated cloud. This cloud can move in

unpredictable directions due to the light variable winds common during inversions. 

Temperature inversions are characterized by increasing temperatures with altitude

and are common on nights with limited cloud cover and light to no wind. They begin

to form as the sun sets and often continue into the morning. Their presence can be

indicated by ground fog; however, if fog is not present, inversions can also be

identified by the movement of smoke from a ground source or an aircraft smoke

generator. Smoke that layers and moves laterally in a concentrated cloud (under low

wind conditions) indicates an inversion, while smoke that moves upward and rapidly

dissipates indicates good vertical air mixing.

SENSITIVE AREAS

The pesticide should only be applied when the potential for drift to adjacent sensitive

areas (e.g. residential areas, bodies of water, known habitat for threatened or

endangered species, non-target crops) is minimal (e.g. when wind is blowing away

from the sensitive areas).

D. Existing Stocks
131

Registrants may generally distribute and sell products bearing old labels/labeling for 26

months from the date of the issuance of this Reregistration Eligibility Decision (RED).

Persons other than the registrant may generally distribute or sell such products for 50

months from the date of the issuance of this RED. However, existing stocks time frames

will be established case-by-case, depending on the number of products involved, the

number of label changes, and other factors. Refer to "Existing Stocks of Pesticide

Products; Statement of Policy"; Federal Register, Volume 56, No. 123, June 26, 1991.

The Agency has determined that registrants may distribute and sell paraquat dichloride

products bearing old labels/labeling for 26 months from the date of issuance of this RED. 

Persons other than the registrant may distribute or sell such products for 50 months from

the date of the issuance of this RED. Registrants and persons other than registrants remain

obligated to meet pre-existing Agency imposed label changes and existing stocks

requirements applicable to products they sell or distribute.
132
133

VI. APPENDICES

135

APPENDIX A. Table of Use Patterns Subject to Reregistration

APPENDIX A. Table of Use Patterns Subject to Reregistration

Appendix A is 213 pages long and is not being included. Copies of Appendix A are available upon request

per the instructions in Appendix E
136

APPENDIX B. Table of the Generic Data Requirements and Studies Used to Make the Reregistration Decision

GUIDE TO APPENDIX B

Appendix B contains listings of data requirements which support the reregistration for active

ingredients within the case Paraquat Dichloride covered by this Reregistration Eligibility

Decision Document. It contains generic data requirements that apply to Paraquat Dichloride in

all products, including data requirements for which a "typical formulation" is the test

substance.

The data table is organized in the following format:

1. Data Requirement (Column 1). The data requirements are listed in the order in which

they appear in 40 CFR Part 158. the reference numbers accompanying each test refer to the

test protocols set in the Pesticide Assessment Guidelines, which are available from the

National Technical Information Service, 5285 Port Royal Road, Springfield, VA 22161 (703)

487-4650.

2. Use Pattern (Column 2). This column indicates the use patterns for which the data

requirements apply. The following letter designations are used for the given use patterns:

A Terrestrial food

B Terrestrial feed

C Terrestrial non-food

D Aquatic food

E Aquatic non-food outdoor

F Aquatic non-food industrial

G Aquatic non-food residential

H Greenhouse food

I Greenhouse non-food

J Forestry

K Residential

L Indoor food

M Indoor non-food

N Indoor medical

O Indoor residential

3. Bibliographic citation (Column 3). If the Agency has acceptable data in its files, this

column lists the identifying number of each study. This normally is the Master Record

Identification (MRID) number, but may be a "GS" number if no MRID number has been

assigned. Refer to the Bibliography appendix for a complete citation of the study.
137

APPENDIX B

Data Supporting Guideline Requirements for the Reregistration of Paraquat Dichloride 

REQUIREMENT USE PATTERN CITATION(S)

PRODUCT CHEMISTRY

61-1 Chemical Identity All N/A

61-2A Start. Mat. & Mnfg. Process All 40479001, 42297601

61-2B Formation of Impurities All 40479001, 42297601

62-1 Preliminary Analysis All 43429001, 40624701, 42297601

62-2 Certification of limits All N/A

62-3 Analytical Method All Data Gap

63-2 Color All 40479001, 42297601

63-3 Physical State All 40479001, 42297601

63-4 Odor All 40479001

63-5 Melting Point All 40479001

63-6 Boiling Point N/A

63-7 Density All 40479001, 42588201

63-8 Solubility All 40479001

63-9 Vapor Pressure All 40479001

63-10 Dissociation Constant All 40479001

63-11 Octanol/Water Partition All 40479001

63-12 pH All 40479001, 42297601

63-13 Stability All 43099701, 40479001, 42297601
Data Supporting Guideline Requirements for the Reregistration of Paraquat Dichloride 

REQUIREMENT USE PATTERN CITATION(S)

138

63-14 Oxidizing/Reducing Action N/A

63-15 Flammability N/A

63-16 Explodability N/A

63-17 Storage stability N/A

63-18 Viscosity N/A

63-19 Miscibility N/A

63-20 Corrosion characteristics N/A

63-21 Dielectric breakdown volt N/A

64-1 Submittal of Samples N/A

ECOLOGICAL EFFECTS

71-1A Acute Avian Oral - Quail/Duck A,B,C,J 00029001,00102038,00160000,

05008363

71-1B Acute Avian Oral - Quail/Duck

TEP 

Not required

71-2A Avian Dietary - Quail A,B,C,J 00022923

71-2B Avian Dietary - Duck A,B,C,J 00022923

71-3 Wild Mammal Toxicity Not required

71-4A Avian Reproduction - Quail A,B,C,J 00110453, 00110454 

71-4B Avian Reproduction - Duck A,B,C,J 00110455

71-5A Simulated Field Study Not required

71-5B Actual Field Study Not required

72-1A Fish Toxicity Bluegill A,B,C,J 40098001, 00162737
Data Supporting Guideline Requirements for the Reregistration of Paraquat Dichloride 

REQUIREMENT USE PATTERN CITATION(S)

139

72-1B Fish Toxicity Bluegill - TEP Not required

72-1C Fish Toxicity Rainbow Trout A,B,C,J 40098001, 00162736, 00162738

72-1D Fish Toxicity Rainbow Trout- TEP Not required

72-2A Invertebrate Toxicity A,B,C,J 40098001, 00114473, GS0262-028

72-2B Invertebrate Toxicity - TEP Not required

72-3A Estuarine/Marine Toxicity - Fish Not required

72-3B Estuarine/Marine Toxicity -

Mollusk

Not required

72-3C Estuarine/Marine Toxicity -

Shrimp

Not required

72-3D Estuarine/Marine Toxicity FishTEP

Not required

72-3E Estuarine/Marine Toxicity Mollusk

- TEP

Not required

72-3F Estuarine/Marine Toxicity Shrimp

- TEP

Not required

72-4A Early Life Stage Fish Not required

72-4B Life Cycle Invertebrate Not required

72-5 Life Cycle Fish Not required

72-6 Aquatic Organism Accumulation Not required

72-7A Simulated Field - Aquatic

Organisms

Not required

72-7B Actual Field - Aquatic Organisms Not required
Data Supporting Guideline Requirements for the Reregistration of Paraquat Dichloride 

REQUIREMENT USE PATTERN CITATION(S)

140

122-1A Seed Germination/Seedling

Emergence

Not required

122-1B Vegetative Vigor Not required

122-2 Aquatic Plant Growth

123-1A Seed Germination/Seedling

Emergence

B,J 42639601

123-1B Vegetative Vigor B,J 42601001

123-2 Aquatic Plant Growth B,J 42601002, 42601003, 42601004, 42601005,

42601006

124-1 Terrestrial Field Not required

124-2 Aquatic Field Not required

141-1 Honey Bee Acute Contact A,B,C,J 05001991, 00028772, 00111488

141-2 Honey Bee Residue on Foliage Not required

141-5 Field Test for Pollinators Not required

TOXICOLOGY

81-1 Acute Oral Toxicity - Rat A,B,C,J 00054573, 00162748, 00081825

00162870,43685001

81-2 Acute Dermal Toxicity -

Rabbit/Rat

A,B,C,J 00054574, 00162748,43685002

81-3 Acute Inhalation Toxicity - Rat A,B,C,J 00046105, 00153733

81-4 Primary Eye Irritation - Rabbit A,B,C,J 00054575, 43685003

81-5 Primary Dermal Irritation - Rabbit A,B,C,J 00054576

81-6 Dermal Sensitization - Guinea Pig A,B,C,J 00155289, 00162744, 43685005
Data Supporting Guideline Requirements for the Reregistration of Paraquat Dichloride 

REQUIREMENT USE PATTERN CITATION(S)

141

81-7 Acute Delayed Neurotoxicity - Hen Not required

82-1A 90-Day Feeding - Rodent Not required

82-1B 90-Day Feeding - Non-rodent (Dog) A,B,C,J 00072416

82-2 21-Day Dermal - Rabbit/Rat A,B,C,J 00156313

82-3 90-Day Dermal - Rodent Not required

82-4 90-Day Inhalation - Rat A,B,C,J 00030788, 00113718

82-5A 90-Day Neurotoxicity - Hen Not required

82-5B 90-Day Neurotoxicity - Mammal Not required

83-1A Chronic Feeding Toxicity - Rodent A,B,C,J 00138637, 40218001

83-1B Chronic Feeding Toxicity - 

Non-Rodent

A,B,C,J 00132474

83-2A Oncogenicity - Rat A,B,C,J 00138637, 00153223, 40183501, 40202401,

40202402, 41317401, 40218001

83-2B Oncogenicity - Mouse A,B,C,J 00087924, 40202403

83-3A Developmental Toxicity - Rat A,B,C,J 00113714

83-3B Developmental Toxicity - Rabbit A,B,C,J 00096338

83-4 2-Generation Reproduction - Rat A,B,C,J 00126783

84-2A Gene Mutation (Ames Test) A,B,C,J 00152690, 00152691

84-2B Structural Chromosomal

Aberration

A,B,C,J 00073487, 00152692, 40202404

84-4 Other Genotoxic Effects A,B,C,J 0015293, 00100442, 00152695, 40202405

85-1 General Metabolism A,B,C,J 00028597, 00036297, 00028598 00055107,

00028599, 00126096
Data Supporting Guideline Requirements for the Reregistration of Paraquat Dichloride 

REQUIREMENT USE PATTERN CITATION(S)

 Guideline fulfilled; No MRID #’s for this study - review dated 2/14/85

142

85-2 Dermal Penetration A,B,C,J 00126096, 00126097, 00126098 00126099,

00153439

86-1 Domestic Animal Safety Not required

OCCUPATIONAL/RESIDENTIAL EXPOSURE

132-1A Foliar Residue Dissipation Not requried

132-1B Soil Residue Dissipation Waived

133-3 Dermal Passive Dosimetry

Exposure

Waived

133-4 Inhalation Passive Dosimetry

Exposure

Waived

231 Estimation of Dermal Exposure at

Outdoor Sites

Not required

232 Estimation of Inhalation Exposure

at Outdoor Sites

Not required

233 Estimation of Dermal Exposure at

Indoor Sites

Not required

234 Estimation of Inhalation Exposure

at Indoor Sites

Not required

ENVIRONMENTAL FATE

160-5 Chemical Identity Not required

161-1 Hydrolysis A,B,C,J Upton3
Data Supporting Guideline Requirements for the Reregistration of Paraquat Dichloride 

REQUIREMENT USE PATTERN CITATION(S)

 Guideline fulfilled; No MRID #’s for this study - review dated 2/14/85

143

161-2 Photodegradation - Water A,B,C,J 40562301

161-3 Photodegradation - Soil A,B,J Pack4

161-4 Photodegradation - Air Not required

162-1 Aerobic Soil Metabolism A,B,C,J 41319301

162-2 Anaerobic Soil Metabolism A,B,C,J 41319302

162-3 Anaerobic Aquatic Metabolism Not required

162-4 Aerobic Aquatic Metabolism Not required

163-1 Leaching/Adsorption/Desorption A,B,C,J 40762701

163-2 Volatility - Lab Not required

163-3 Volatility - Field Not required

164-1 Terrestrial Field Dissipation A,B,C 41352101, 41352102

164-2 Aquatic Field Dissipation Not required

164-3 Forest Field Dissipation Not required

164-5 Long Term Soil Dissipation A,B 42802101, 42802102, 42738701

42738702

165-1 Confined Rotational Crop A,B 41645601

165-2 Field Rotational Crop Not required

165-3 Accumulation - Irrigated Crop Not required

165-4 Bioaccumulation in Fish Not required
Data Supporting Guideline Requirements for the Reregistration of Paraquat Dichloride 

REQUIREMENT USE PATTERN CITATION(S)

144

165-5 Bioaccumulation - Aquatic

NonTarget

Waived

166-1 Ground Water - Small Prospective Not required

166-2 Ground Water - Small

Retrospective

Not required

166-3 Ground Water - Irrigated

Retrospective

Not required

201-1 Droplet Size Spectrum ALL DATA GAP

202-1 Drift Field Evaluation ALL DATA GAP

RESIDUE CHEMISTRY

171-3 Directions for Use ALL DATA GAP

171-4A Nature of Residue - Plants A,B 00065602, 00065604, 00091365, 00091366,

00091378, 00114411

42324301, 43492602, 43492603

171-4B Nature of Residue - Livestock A,B 00028596, 00028597, 00028598, 00028599,

00089748, 00114414

00114422, 00117783, 42324302
Data Supporting Guideline Requirements for the Reregistration of Paraquat Dichloride 

REQUIREMENT USE PATTERN CITATION(S)

145

171-4C Residue Analytical Method - Plants A,B 00025269, 00030476, 00032141 00032240,

00037058, 00090400 

00112663, 00114411, 00114421, 00114446,

00114453, 00114465 

00114466, 00138258, 40048401, 40098502,

41151508, 41151514

41151519, 41151522, 41151528, 42217402,

42217403, 42217404

42217405, 43492603

171-4D Residue Analytical Method -

Animal

A,B 00036306, 00037058, 00112663, 00114421,

00114422, 40943701

42217401, 43226902, 43226903, 43492601

171-4E Storage Stability A,B 00037057, 00113702, 40943702, 40943703,

41151511, 41151535

41151536, 41151537, 41151538, 41151539,

41151540, 41151541

42217401, 42217440 through 42217450

171-4F Magnitude of Residues - Potable

H2O

Not required

171-4G Magnitude of Residues in Fish Not required

171-4H Magnitude of Residues - Irrigated

Crop

Not required

171-4I Magnitude of Residues - Food

Handling

Not required

171-4J Magnitude of Residues -

Meat/Milk/Poultry/Egg

A,B
Data Supporting Guideline Requirements for the Reregistration of Paraquat Dichloride 

REQUIREMENT USE PATTERN CITATION(S)

146

- Milk and the fat, meat, and meat

byproducts of cattle, goats, hogs,

horses, and sheep

00036305, 00090978, 00114414, 00114422,

00117783

- Eggs and the fat, meat, and meat

byproducts of poultry

00038503, 40943704

171-4k Magnitude of Residue in Plants: A,B

Root and Tuber Vegetables Group

- Carrots 00030476

- Cassava 00160250

- Potatoes 00033612, 00091376, 00105060

- Sugar beet roots 00113709, 41151514, 42217418

- Taniers 00160250

- Taro corms 41017901

- Turnips, roots 00030476

- Yams 00160250

Leaves of Root and Tuber

Vegetables Group

- Sugar beet tops 00113709, 41151514, 42217418

- Taro foliage DATA GAP

Bulb Vegetables Group

- Onions, dry bulb and green 00113680, 00136330
Data Supporting Guideline Requirements for the Reregistration of Paraquat Dichloride 

REQUIREMENT USE PATTERN CITATION(S)

147

Leafy Green Vegetables (except

Brassica veg.) Group

 - Lettuce 0114474, 00139741

- Rhubarb 00031863

Brassica Leafy Vegetables Group

- Broccoli 00103245

- Cabbage 00103245

- Cauliflower 00030476

- Chinese cabbage 00030476

- Collards 00030476

Legume Vegetables Group

- Beans (succulent, lima, snap and

dry)

00030476, 00033223

- Guar 00114420

- Peas (succulent) 00030476

- Pigeon peas 00147206

- Soybean seed and aspirated grain

fractions 

00015768, 00025268, 00015769 00015771,

00032427, 00015772, 00015774, 00098579,

00015775, 00030676, 00015770, 00031742

00033530, 00015773, 00034112

00109728, 00114446, 41151524, 41151530,

42217426, 42217438, 43226904, DATA GAP

for aspirated grain fractions
Data Supporting Guideline Requirements for the Reregistration of Paraquat Dichloride 

REQUIREMENT USE PATTERN CITATION(S)

148

Foliage of Legume Vegetable

Group

- Bean forage, hay, and straw 00030476, 00033223, 41151504, 42217409

 - Pea vines and hay 00030476, 41151505, 42217410

- Soybeans forage and hay 00015768, 00025268, 00015769, 00030676,

00015770, 00032427,

00015771, 00033530, 00015772, 00034112,

00015773, 00098579,

00015774, 00109728, 00015775, 41151524,

41151527, 41151530, 42217426, 42217429,

42217438

Fruiting Vegetables (except

cucurbits) Group

00030476, 00033223, 00059596, 41151507,

42217412

Cucurbit Vegetable Group 00027298, 00030476, 00033223, 41151503,

42217401

Citrus Fruits Group 00023329, 00027298, 00033695, 00035665,

00070779, 00070780, 00113821

Pome Fruits Group

- Apples 00033695, 00035664, 00070779, 00113821

- Pears 00033695, 00035664, 00113821

Stone Fruits Group

- Apricots 00035663, 00113821

- Cherries 00023329, 00033695, 00027965, 00113821

- Nectarines 00035663, 00113821
Data Supporting Guideline Requirements for the Reregistration of Paraquat Dichloride 

REQUIREMENT USE PATTERN CITATION(S)

149

- Peaches 00023329, 00035663, 00023883, 00033035,

00113709, 00033694, 00070780, 00027695,

00070784

00113821, 00033695

- Plums 00023329, 00035663, 00033035, 00113709,

00033695, 00114436, 42217431

Small Fruits and berries Group 

 

00023329, 00113709, 00023883, 00033695,

00138258, 00070780

00113821, 00027968, 00114411, 

Tree Nuts Group 

 

00023329, 00035666, 00023883 00070780,

00027971, 00113821

00030929, 00033695

Cereal Grains Group 

- Barley grain 00114411

- Corn, field, grain and aspirated

grain fractions

00015751, 00023512, 00015752, 

00015955, 00030647, 00016441, 00031744,

00016442, 00033223, 00016444, 00093182,

00016445, 00023131, 41151523, 42217437,

DATA GAP for aspirated grain fraction 

- Corn, sweet 00030683, 00033223, 41151506

- Oat grain 00114411

- Rice grain 42670801

- Sorghum grain and aspirated

grain fractions

00023131, 00026963, 00027178, 00033223,

00070872, 00113709, 41151531, 42217430

- Wheat grain and aspirated grain

fractions

00027311, 00113693, 00114411 00140828,

41151525, 42217439
Data Supporting Guideline Requirements for the Reregistration of Paraquat Dichloride 

REQUIREMENT USE PATTERN CITATION(S)

150

Forage, Fodder, Hay, and Straw of

Cereal Grains Group

- Barley forage, hay, and straw 00114411

- Corn, field, forage and fodder 00015751, 00015752, 00015955, 00016441,

00016442, 00016444, 00016445, 00023131,

00023512, 00027972, 00027973, 00030647,

00031519, 00031744, 00033208, 00033223,

00093182, 41151523, 42217437

- Corn, sweet, forage, and fodder 00030683, 00033223, 41151506, 42217411

- Oat forage, hay, and straw 00114411

- Rice straw 42670801

- Sorghum forage and fodder 00026963, 00027178, 00070872, 41151531,

42217430

- Wheat forage, hay, and straw 00027311, 00114411, 41151525, 42217401,

42217439, 42961401 DATA GAP 

Grass Forage, Fodder,and Hay

Group

00033223, 00058773, 00114424, 00114466,

00117783, 00160817, 41151515, 41151516,

41151526, 42217419, 42217420, 42217425

DATA GAP

- Alfalfa 00032140, 00114464, 00058774 00114465,

00105061, 00114467

00114405, 00126671, 00114421 00128624,

00114424, 00165364, 41151501, 42217406

- Birdsfoot Trefoil 00114424, 41151542, 42217434

- Clover 00114424, 00117783, 41151509, 42217414

Miscellaneous Commodities
Data Supporting Guideline Requirements for the Reregistration of Paraquat Dichloride 

REQUIREMENT USE PATTERN CITATION(S)

151

- Acerola ` 00128221

- Asparagus 00033532, 00113675

- Avacodos GS0262-006

- Bananas 00113709, 00139733

- Coffee 00139734

- Cotton, seed, and gin byproducts 00031739, 00033612, 00091372,

42217401,DATA GAP for cotton gin

byproducts 

- Figs 00139735, 41151502, 42217407, 42961401

- Guava 00114419

- Hops, cones, dried 00113686, 41151521, 42217435

- Kiwifruit 00088195

- Mint hay 00137859

- Olives 00139737

- Papaya 00033695

- Passion Fruit 00037056

- Peanut nutmeats, hay, and hulls 40098501, 40098503

- Pineapple 00114411, 41151534, 42217432, 42217433

- Pistachios 00027550, 00035666, 00113699

- Safflower seed and forage 00114411

- Strawberries 00138258

- Sugarcane 00114411, 00114469
Data Supporting Guideline Requirements for the Reregistration of Paraquat Dichloride 

REQUIREMENT USE PATTERN CITATION(S)

152

- Sunflower seeds and forage 00106570, 00114422, 41151512, 42217416

171-4(l) Magnitude of Residues in

Processed Food/Feed

A,B

- Citrus fruits 00033695

- Coffee 41151529, 42217401, 42217428

- Corn, field 00114426, 41151528, 42217401, 42217427

- Cottonseed 00091372

- Figs 41151502, 42217407, 42961401

- Grapes DATA GAP

- Hops 41151521, 42217435

- Mint 00137859, 42217401

- Olives 41151522, 42217401

- Pineapples 41151533, 42217432

- Plums 41151532, 42217401, 42217431

- Potatoes 41151508, 42217401, 42217413

- Sorghum 00114421, 41151520, 42217424

- Soybeans 00034112

- Sugar beets 41151519, 42217401, 42217423

- Sugarcane 00114411, 00114469, 41151518, 42217422

- Sunflower 00114422

- Tomatoes 41151510, 42217415
Data Supporting Guideline Requirements for the Reregistration of Paraquat Dichloride 

REQUIREMENT USE PATTERN CITATION(S)

153

- Wheat 41151517, 42217401, 42217421

171-5 Reduction of Residues N/A

171-6 Proposed Tolerance N/A

171-7 Support for Tolerance N/A

171-13 Analtyical Reference Standard N/A
·
155

APPENDIX C. Citations Considered to be Part of the Data Base Supporting the

Reregistration of Paraquat Dichloride

GUIDE TO APPENDIX C

1. CONTENTS OF BIBLIOGRAPHY. This bibliography contains citations of all studies

considered relevant by EPA in arriving at the positions and conclusions stated elsewhere in

the Reregistration Eligibility Document. Primary sources for studies in this bibliography

have been the body of data submitted to EPA and its predecessor agencies in support of

past regulatory decisions. Selections from other sources including the published literature,

in those instances where they have been considered, are included.

2. UNITS OF ENTRY. The unit of entry in this bibliography is called a "study". In the case

of published materials, this corresponds closely to an article. In the case of unpublished

materials submitted to the Agency, the Agency has sought to identify documents at a level

parallel to the published article from within the typically larger volumes in which they

were submitted. The resulting "studies" generally have a distinct title (or at least a single

subject), can stand alone for purposes of review and can be described with a conventional

bibliographic citation. The Agency has also attempted to unite basic documents and

commentaries upon them, treating them as a single study.

3. IDENTIFICATION OF ENTRIES. The entries in this bibliography are sorted numerically

by Master Record Identifier, or "MRID number". This number is unique to the citation,

and should be used whenever a specific reference is required. It is not related to the sixdigit "Accession Number" which has been used to identify volumes of submitted studies

(see paragraph 4(d)(4) below for further explanation). In a few cases, entries added to the

bibliography late in the review may be preceded by a nine character temporary identifier. 

These entries are listed after all MRID entries. This temporary identifying number is also

to be used whenever specific reference is needed.

4. FORM OF ENTRY. In addition to the Master Record Identifier (MRID), each entry

consists of a citation containing standard elements followed, in the case of material

submitted to EPA, by a description of the earliest known submission. Bibliographic

conventions used reflect the standard of the American National Standards Institute (ANSI),

expanded to provide for certain special needs.

a Author. Whenever the author could confidently be identified, the Agency has chosen to

show a personal author. When no individual was identified, the Agency has shown an

identifiable laboratory or testing facility as the author. When no author or laboratory

could be identified, the Agency has shown the first submitter as the author.

b. Document date. The date of the study is taken directly from the document. When the

date is followed by a question mark, the bibliographer has deduced the date from the

evidence contained in the document. When the date appears as (19??), the Agency was

unable to determine or estimate the date of the document.

c. Title. In some cases, it has been necessary for the Agency bibliographers to create or

enhance a document title. Any such editorial insertions are contained between square

brackets.
156

d. Trailing parentheses. For studies submitted to the Agency in the past, the trailing

parentheses include (in addition to any self-explanatory text) the following elements

describing the earliest known submission:

(1) Submission date. The date of the earliest known submission appears immediately

following the word "received."

(2) Administrative number. The next element immediately following the word

"under" is the registration number, experimental use permit number, petition

number, or other administrative number associated with the earliest known

submission.

(3) Submitter. The third element is the submitter. When authorship is defaulted to

the submitter, this element is omitted.

(4) Volume Identification (Accession Numbers). The final element in the trailing

parentheses identifies the EPA accession number of the volume in which the

original submission of the study appears. The six-digit accession number follows

the symbol "CDL," which stands for "Company Data Library." This accession

number is in turn followed by an alphabetic suffix which shows the relative

position of the study within the volume.
BIBLIOGRAPHY

MRID CITATION

______________________________________________________

157

--------- Memo dated 9/26/95, entitled "Paraquat dichloride formulated as Starfire

Herbicide or Gramaxone Extra -- Worker Exposure Studies" from Krystyna

K. Locke, Toxicology Branch I, to Mary Clock, RCAB.

--------- OREB memo entitled "Review of Paraquat Acute Illness Data" from Jerome

Blondell, Ph.D. Health Statistician, to Christiana Manville.

--------- Gunther , Francis A., Ed. Residue Reviews. Residues of Pesticides and

Other Foreign Chemicals in Foods and Feeds. Springeer-Verlag, New York

Inc.: 1968, Vol. 23, p. 97.

--------- Summers, L.A. Bipyridium Herbicides. Academic Press: 1980.

--------- Blondell JM. 1994. Memorandum to Joshua First. Review of Poison

Control Center Data Call In. December 5, 1994. U.S. Environmental

Protection Agency, Washington, DC.

--------- California Department of Food and Agriculture. 1983-1989. Pesticide Use

Report Annual (for years 1982-1988). Sacramento, California.

--------- California Department of Pesticide Regulation. 1995. Case Reports

Received by the California Pesticide Illness Surveillance Program in Which

Health Effects Were Attributed to Exposure to Paraquat, Alone or In

Combination, 1982-1992.

--------- Garnier R, Chataigner D, Efthymiou M-L, Morallon I, Bramary F. 1994. 

Paraquat poisoning by skin absorption: report of two cases. Veterinary and

Human Toxicology 36313-16.

--------- Gianessi LP. A National Pesticide Usage Data Base. 1986. Resources for

the Future, Washington, DC.

--------- Keefe TJ, Savage EP, Wheeler HW. 1990. Third National Study of

Hospitalized Pesticide Poisonings in the United States, 1977-1982. 

Epidemiologic Studies Center, Colorado State University, Fort Collins,

Colorado.

--------- Litovitz TL, Schmitz BF, Bailey KM. 1990. 1989 Annual report of the

American Association of Poison Control Centers National Data Collection

System. American Journal of Emergency Medicine 8:394-442.
BIBLIOGRAPHY

MRID CITATION

______________________________________________________

158

--------- Litovitz TL, Bailey KM, Schmitz BF, et al. 1991. 1990 Annual report of the

American Association of Poison Control Centers National Data Collection

System. American Journal of Emergency Medicine 9:461-509.

--------- Litovitz TL, Holm KC, Bailey KM, et al. 1992. 1991 Annual report of the

American Association of Poison Control Centers National Data Collection

System. American Journal of Emergency Medicine 10:452-505.

--------- Litovitz TL, Holm KC, Clancy C, et al. 1993. 1992 Annual report of the

American Association of Poison Control Centers Toxic Exposure

Surveillance System. American Journal of Emergency Medicine 11:494-555

--------- Litovitz TL, Clark LR, Soloway RA. 1994. 1993 Annual report of the

American Association of Poison Control Centers Toxic Exposure

Surveillance System. American Journal of Emergency Medicine 12:546-584

--------- Morgan DP. 1989. Recognition and Management of Pesticide Poisonings. 

U.S. Environmental Protection Agency, Washington, DC.

--------- National Center for Health Statistics. 1983-1993. Vital Statistics of the

United States (for the years 1980-1989) Volume II, Part A. Public Health

Service, U.S. Government Printing Office, Washington, DC.

--------- Smith JG. 1988. Paraquat poisoning by skin absorption: a review. Human

Toxicology 7:15-19.

--------- Stevens JT and Sumner DD. 1991. Herbicides. Chapter 20 (pp.1356-76) in

Handbook of Pesticide Toxicology, Volume 3. Edited by WJ Hayes and ER

Laws. Academic Press, San Diego.

--------- Tinoco R, Tinoco R, Parsonnet J, Halperin D. 1993. Paraquat poisoning in

southern Mexico: a report of 25 cases. Archives of Environmental Health

48:78-80.

GS0262-006 Chevron Chemical Co. (1966) Residue Data Sheet: Avocados: Paraquat: 

Test No. T-1020. (Unpublished study prepared by Diablo Laborities, Inc. 

4p.

GS0262028 US EPA (1979) 48-Hour EC50: Paraquat dichloride 29.1%: Daphnia

Magna: Test 2431. Unpublished report prepared by Terrestrial Aquatic

Biology Laboratory. 1 p.
BIBLIOGRAPHY

MRID CITATION

______________________________________________________

159

00015751 Rose, W.; Worsham, D.; Slagowski, J.L. (1978) Metolachlor (Dual® 8E);

Atrazine (AAtrex® 80W); Paraquat (Paraquat CL): AG-A No. 4959 I,II. 

(Unpublished study received Mar 16, 1979 under 100-583; prepared in

cooperation with EN-CAS Laboratories and Chevron Chemical Co.,

submitted by Ciba-Geigy Corp., Greensboro, N.C.; CDL:237819-F)

00015752 Kern, C.L.; Staniforth, D.; Slagowski, J.L. (1978) Metolachlor (Dual® 8E);

Atrazine (AAtrex® 80W or 4L); Paraquat (Paraquat CL): AG-A No. 5000

I,II. (Unpublished study received Mar 16, 1979 under 100-583; prepared in

cooperation with Iowa State Univ., EN-CAS Laboratories and Chevron

Chemical Co., submitted by Ciba-Geigy Corp., Greensboro, N.C.;

CDL:237819-H)

00015768 Kincaid, L.; Slagowski, J.L. (1978) Metolachlor + Linuron + Paraquat; Dual

8E + Lorox 50W + Paraquat 2CL: AG-A No. 4762 I,II. (Unpublished study

including letter dated May 23, 1978 from J.D. Riggleman to Robert A.

Kahrs, received Mar 16, 1979 under 100-583; prepared in cooperation with

Chevron Chemical Co. and E.I. du Pont de Nemours & Co., Inc., submitted

by Ciba-Geigy Corp., Greensboro, N.C.; CDL:237821-J) 

00015769 Searcy, V.; Herman, D.; Slagowski, J.L. (1978) Metolachlor + Linuron +

Paraquat: Dual 8E + Lorox 50W + Paraquat 2CL: AG-A No. 4892 I,II. 

(Unpublished study including letter dated May 23, 1978 from J.D.

Riggleman to Robert A. Kahrs, received Mar 16, 1979 under 100-583;

prepared in cooperation with Chevron Chemical Co. and E.I. du Pont de

Nemours & Co., Inc., submitted by Ciba-Geigy Corp., Greensboro, N.C.;

CDL:237821-L) 

00015770 Schnappinger, M.G.; Slagowski, J.L. (1978) Metolachlor + Linuron +

Paraquat (Dual 8E + Lorox 50W + Paraquat 2CL): AG-A No. 4915 I, II. 

(Unpublished study including letter dated May 23, 1978 from J.D.

Riggleman to Robert A. Kahrs, received Mar 16, 1979 under 100-583;

prepared in cooperation with Chevron Chemical Co. and E.I. du Pont de

Nemours & Co., Inc., submitted by Ciba-Geigy Corp., Greensboro, N.C.;

CDL:237821-L) 

00015771 Rose, W.; Worsham, D.; Slagowski, J.L. (1978) Metolachlor + Linuron +

Paraquat: Dual® 8E + Lorox 50W + Paraquat 2CL: AG-A No. 4955 I,II. 

(Unpublished study including letter dated May 23, 1978 from J.D.

Riggleman to Robert A. Kahrs, received Mar 16, 1979 under 100-583;

prepared in cooperation with Rocky Mount Experiment Station, Chevron

Chemical Co. and E.I. du Pont de Nemours & Co., Inc., submitted by

Ciba-Geigy Corp., Greensboro, 
BIBLIOGRAPHY

MRID CITATION

______________________________________________________

160

00015772 Kincaid, L.; Slagowski, J.L. (1978) Metolachlor (Dual® 8E); Metribuzin

(Sencor 50W); Paraquat (2Cl): AG-A No. 4764 I,II. (Unpublished study

including letter dated May 23, 1978 from J.D. Riggleman to Robert A.

Kahrs, received Mar 16, 1979 under 100-583; prepared in cooperation with

E.I. du Pont de Nemours & Co., Inc. and Chevron Chemical Co., submitted

by Ciba-Geigy Corp., Greensboro, N.C.; CDL:237821-M) 

00015773 Searcy, S.; Herman, D.; Slagowski, J.L. (1978) Metolachlor (Dual® 8E);

Metribuzin (Sencor 50W); Paraquat (2Cl): AG-A No. 4894 I,II. 

(Unpublished study including letter dated May 23, 1978 from J.D.

Riggleman to Robert A. Kahrs, received Mar 16, 1979 under 100-583;

prepared in cooperation with E.I. du Pont de Nemours & Co., Inc. and

Chevron Chemical Co., submitted by Ciba-Geigy Corp., Greensboro, N.C.;

CDL:237821-O) 

00015774 Schnappinger, M.G.; Slagowski, J.L. (1978) Metolachlor (Dual® 8E);

Metribuzin (Sencor 50W); Paraquat (2 Cl): AG-A No. 4916 I, II. 

(Unpublished study including letter dated May 23, 1978 from J.D.

Riggleman to Robert A. Kahrs, received Mar 16, 1979 under 100-583;

prepared in cooperation with E.I. du Pont de Nemours & Co., Inc. and

Chevron Chemical Co., submitted by Ciba-Geigy Corp., Greensboro, N.C.;

CDL:237821-P) 

00015775 Rose, W.; Worsham, D.; Slagowski, J.L. (1978) Metolachlor (Dual® 8E);

Metribuzin (Sencor 50W); Paraquat (Cl): AG-A No. 4957 I,II. 

(Unpublished study including letter dated May 23, 1978 from J.D.

Riggleman to Robert A. Kahrs, received Mar 16, 1979 under 100-583;

prepared in cooperation with E.I. du Pont de Nemours & Co., Inc. and

Chevron Chemical Co., submitted by Ciba-Geigy Corp., Greensboro, N.C.;

CDL:237821-Q) 

00015955 Luke, J.E.; Slagowski, J.L. (1978) Metolachlor (Dual® 8E); Atrazine

(AAtrex® 80W); Paraquat (Paraquat CL): AG-A No. 4964. (Unpublished

study received Mar 16, 1979 under 100-583; prepared in cooperation with

EN-CAS Laboratories and Chevron Chemical Co., submitted by Ciba-Geigy

Corp., Greensboro, N.C.; CDL:237819-G) 

00016441 Thomas, J.; Herman, D.; Slagowski, J.L. (1977) Residue Report: Field Corn:

AG-A No. 4167 II. (Unpublished study received Nov 10, 1977 under

100-EX-59; prepared in cooperation with Chevron Chemical Co., submitted

by Ciba-Geigy Corp., Greensboro, N.C.; CDL:232192-I) 
BIBLIOGRAPHY

MRID CITATION

______________________________________________________

161

00016442 Coan, R.M.; Karusta, G.; Slagowski, J.L. (1977) Residue Report: Field

Corn: AG-A No. 4187 II,III. (Unpublished study received Nov 10, 1977

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00073487 Anderson, D.; Richardson, C.R.; Howard, C.A.; et al. (1978) Paraquat: A

cytogenetic study in the rat: Report No. CTL/P/367. (Unpublished study

received May 29, 1979 under 239-2186; prepared by Imperial Chemical Co.,

Richmond, Calif.; CDL:238662-A) 

00081825 Clark, D.G. (1965) The Acute Toxicity of Paraquat: Report No. IHR/170. 

(Unpublished study received Feb. 23, 1965 under 5G0440; prepared by

Imperial Chemical Industries, Ltd., England, submitted by Chevron

Chemical Co., Richmond, Calif.; CDL:090478-C).

00087924 Litchfield, M.H.; Sotheran, M.F.; Banham, P.B.; at al. (1981) Paraquat: 

Lifetime Feeding Study in the Mouse: Report No. CTL/P/556. 

(Unpublished study received Dec. 22, 1981 under 239-2186; prepared by

Imperial Chemical Industries, Ltd., England, submitted by Chevron

Chemical Co., Richmond, Calif.;CDL:246504-A)

00088195 Interregional Research Project Number 4 (1977) Summary of Residue

Chemistry Data: [Paraquat]. (Compilation; unpublished study received Dec

4, 1981 under 2E2611; CDL:070510-A) 

00089748 Stevens, M.A.; Walker, G.H.; Walley, J.K. (1964) The Excretion of

C-Paraquat by the Cow: Report No. THR/164. (Unpublished study 14

received Aug 30, 1965 under 239-1994; prepared by Imperial Chemical

Industries, Ltd., England, submitted by Chevron Chemical Co., Richmond,

Calif.; CDL:050874-E) 
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00090400 California Chemical Company (1965) Analysis of Paraquat Residues: Bio

Assay (Lemna minor): File 740.10. Method RM-8b dated Feb 9, 1965. 

(Unpublished study received Feb 25, 1965 under 5G0440; CDL:090479-G) 

00090978 Imperial Chemical Industries Limited (1966) Bipyridylium Herbicides:

Paraquat Grazing Trial. (Unpublished study received May 6, 1966 under

6F0483; submitted by Chevron Chemical Co., Richmond, Calif.;

CDL:090542-AA) 

00091365 Chevron Chemical Company (1964?) The Fate of Paraquat in Plants. 

(Unpublished study received Mar 2, 1966 under 6F0483; CDL: 090543-B) 

00091366 Plant Protection, Limited (1966) Bipyridylium Herbicides: Residues in

Potato Tubers following Haulm Desiccation with C-Paraquat. 14

(Unpublished study received Mar 2, 1966 under 6F0483; submitted by

Chevron Chemical Co., Richmond, Calif.; CDL: 090543-C) 

00091372 Chevron Chemical Company (1966) Summary: Paraquat. (Compilation;

unpublished study received Mar 2, 1966 under 6F0483; CDL: 090543-I) 

00091376 Chevron Chemical Company (1965) Residue Data Sheet: Potatoes.

(Compilation; unpublished study, including test nos. T-301, T-312,

T-323A..., received Mar 2, 1966 under 6F0483; CDL: 090543-M) 

00091378 Slade, P. (1965?) Bipyridylium Herbicides: The Behavior of the

Methylsulphate Anion in Plants following Foliar Application of Paraquat

Dimethylsulfate. (Unpublished study received Mar 2, 1966 under 6F0483;

submitted by Chevron Chemical Co., Richmond,Calif.; CDL:090543-P) 

00093182 Shell Chemical Company (1973) Supportive Residue Data for Bladex®

Herbicide Tank Mix Combination with Paraquat (Minimum Till Corn). 

Includes methods MMS-R-202-3 dated Oct 1969 and RM-8 dated Feb 20,

1970. (Compilation; unpublished study received Jul 11, 1973 under

201-279; CDL:000987-A) 

00096338 Hodge, M.C.E.; Palmer, S.; Weight, T.M.et al. (1977) Paraquat Dichloride: 

Teratogenicity Study in the Mouse: Report No. CTL/P/364. (Unpublished

study received March 5, 1981 under 239-2186; submitted by Chevron

Chemical Co., Richmond, CA; CDL:244499-A)
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00098579 Chevron Chemical Company (1980) Paraquat Soybeans. (Compilation;

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00100441 Anderson, D. (1976) Paraquat: Estimation of Mutagenic Potential in the

Salmonella typhimurium Mutagenicity Assay: Report No. CTL/P/243. 

(Unpublished study received Jan. 15, 1979 under 239-2186; submitted by

Chevron Chemical Co. Richmond, CA; CDL:236764-B)

00100442 McGregor, D. (1974 ?) Dominant Lethal Study in Mice of Paraquat 401551:

I.R.I. Report No. 145. (Unpublished study received Jan. 15, 1979 under

239-2186; prepared by Inveresk Research International, Scotland, submitted

by Chevron Chemical Co., Richmond, CA; CDL:236764-C)

00102038 Hudson, R.; Tucker, R.; Haegele, M. (1972) Effect of age on sensitivity: 

Acute oral toxicity of 14 pesticides to mallard ducks of several ages. 

Toxicology and Applied Pharmacology (22):556-561. (Alos in unpublished

submission received Oct. 26, 1977 under 1016-69; submitted by Union

Carbide Corp., Arlington VA; CDL:096397-E)

00103245 Slagowski, J. (1981) Residue Data Sheet: [Paraquat]. (Unpublished study

received Jun 4, 1982 under 239-2186; submitted by Chevron Chemical Co.,

Richmond, CA; CDL:247643-A) 

00105060 Chevron Chemical Co. (1980) Residue Chemistry Data to Support an 

Amendment of the Paraquat CL Label for Potatoes to Include

Preplant-preemergence Treatment by Ground or Aerial Application. 

(Unpublished study received Jun 16, 1982 under 239-2186; CDL:

247683-A) 

00105061 Chevron Chemical Co. (1981) Residue Chemistry Data to Support an 

Amendment of the Paraquat CL Label for Alfalfa to Add Aerial Application. 

(Unpublished study received Jun 16, 1982 under 239-2186; CDL:247684-A) 

00106570 Illinois (1982) Ortho Paraquat CL Special Local Need 24(C) Request:

No-till Sunflowers. (Compilation; unpublished study received Jul 12, 1982

under IL 82/11; CDL:247838-A) 

00109728 Chevron Chemical Co. (1974) Summary: Residues in Soybeans after a

Tank-mix, No-till Application of Paraquat CL, Lasso, and Lorox.
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(Compilation; unpublished study received Jun 24, 1975 under 239-2186;

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00110453 Fink, R.; Beavers, J.; Joiner, G.; et al. (1981) Subacute

Feeding-Reproduction Screening Bioassay (Bobwhite Quail): Paraquat

Technical (SX-1305): Project No. 162-138; S-1994. Final rept.

(Unpublished study received Aug 18, 1982 under 239-2186; prepared by

Wildlife International Ltd., submitted by Chevron Chemical Co., Richmond,

CA; CDL:248133-B)

00110454 Fink, R.; Beavers, J.; Joiner, G.; et al. (1982) One-generation

Reproduction--Bobwhite Quail: Paraquat Technical (SX-1305): Project No.

162-142. Final rept. (Unpublished study received Aug 18, 1982 under

239-2186; prepared by Wildlife International Ltd., submitted by Chevron

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00110455 Fink, R.; Beavers, J.; Joiner, G.; et al. (1982) One-generation

Reproduction--Mallard Duck: Paraquat Technical (SX-1305): Project No.

162-145. Final rept. (Unpublished study received Aug 18, 1982 under

239-2186; prepared by Wildlife International Ltd., submitted by Chevron

Chemical Co., Richmond, CA; CDL: 248133-D)

00111488 Moffett, J.; Morton, H.; MacDonald, R. (1972) Toxicity of some herbicidal

sprays to honey bees. Journal of Economic Entomology 65(1):32-36. (Also

In unpublished submission received Sep 26, 1974 under 464-323; submitted

by Dow Chemical U.S.A., Midland, MI; CDL:120345-H)

00112663 Chevron Chemical Co. (1966) [Residue Determination of Paraquat in Dust,

Plant and Animal Tissues]. (Compilation; unpublished study received Jul 1,

1966 under 6F0483; CDL:092772-D) 

00113675 Interregional Research Project No. 4 (1976) The Results of Tests on the

Amount of Paraquat Residues Remaining in or on Asparagus, Including a

Description of the Analytical Method Used. (Compilation; unpublished

study received Jul 3, 1976 under 6E1845; CDL:095940-A) 

00113680 Interregional Research Project No. 4 (1978) Paraquat: Onions: Residue

Chemistry Data. (Compilation; unpublished study received Mar 1, 1978

under 7E1931; CDL:096957-A) 
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00113686 Chevron Chemical Co. (1975) The Results of Tests on the Amount of

Residue Remaining, Including a Description of the Analytical Methods

Used: [Paraquat]. (Compilation; unpublished study received Apr 10, 1975

under 5F1619; CDL:098184-B) 

00113693 Chevron Chemical Co. (1978) Paraquat CL--Winter Wheat. (Compilation;

unpublished study received Jun 13, 1979 under 239-2186; CDL:098333-A) 

00113699 Interregional Research Project No. 4 (1978) The Results of Tests on the

Amount of Paraquat Residues Remaining in or on Pistachios Including a

Description of the Analytical Method Used. (Compilation; unpublished

study received Jul 6, 1979 under 9E2229;CDL:098378-A) 

00113702 Interregional Research Project No. 4 (1979) Results of Tests and 

Descriptions of Analytical Methods Used Regarding the Amount of

Paraquat Residue in or on Rhubarb. (Compilation; unpublished study

received May 21, 1980 under 0E2364; CDL:099442-A) 

00113707 Clinch, R.; Middleton, M.; Winchester, J. (1962) Bipyridylium Herbicides: 

Adsorption of Diquat and Paraquat Salts and Formulations by Soils: Report

No. PP/E/178. (Unpublished study received Aug. 1, 1962 under unknown

admin. no.; submitted by Imperial chemical Industries Ltd., London, Eng.;

CDL:121729-A)

00113709 Chevron Chemical Co. (1964) Paraquat Residue [sic] Data. (Compilation;

unpublished study received Oct 22, 1964 under 239-EX-53;

CDL:122824-A) 

00113714 Hodge, M.; Palmer, S.; Weight, T.; et al. (1977) Paraquat Dichloride:

Teratogenicity Study in the Rat: Report No. CTL/P/365. (Unpublished

study received Jan. 15, 1979 under 239-2186; submitted by Chevron

Chemical Co., Richmond, CA;CDL:236763-A) 

00113718 Hardy, C.; Grimshaw, P.; Cobb, L.; at al. (1979) Three-Week Inhalation

Study in Rats Exposed to an Aerosol of Paraquat: ICI/254/7949. 

(Unpublished study received Oct. 16, 1979 under 239-2186; prepared by

Huntingdon Research Centre, England; submitted by Chevron Chemical

Co., Richmond, CA; CDL:241188-A)
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00113821 Stauffer Chemical Co. (1979) Residue Data: Summaries and Analytical Data

for Devrinol, Devrinol/Simazine and Devrinol/Paraquat on Citrus. 

(Compilation; unpublished study received Nov 13, 1979 under 476-2108;

CDL:241323-A) 

00114405 Chevron Chemical Co. (1974) Ortho Paraquat CL Residue Data from

Dormant Application on Alfalfa and Clover. (Compilation; unpublished

study received Oct 25, 1974 under 239-2186; CDL:028529-B) 

00114411 Chevron Chemical Co. (1970) The Results of Tests on the Amount of

Residue Remaining, Including a Description of the Analytical Methods

Used: [Paraquat]. (Compilation; unpublished study received Sep 24, 1970

under 1F1014; CDL:091759-A) 

00114414 Chevron Chemical Co. (1967) Name, Chemical Identity and Composition of

the Pesticide Chemical: [Paraquat]. (Compilation; unpublished study

received Apr 3, 1967 under 7F0592; CDL:092880-A) 

00114419 Chevron Chemical Co. (1972) The Results of Tests on the Amount of

Residue Remaining, Including a Description of the Analytical Methods

Used: [Paraquat]. (Compilation; unpublished study received Nov 27, 1972

under 3G1325; CDL:093570-B) 

00114420 Interregional Research Project No. 4 (1974) [Residues of Paraquat CL in

Guar]. (Compilation; unpublished study received Sep 17, 1974 under

5E1549; CDL:094213-A) 

00114421 Chevron Chemical Co. (1975) The Results of Tests on the Amount of

Residue Remaining, Including a Description of the Analytical Method Used:

[Paraquat]. (Compilation; unpublished study received Feb 10, 1975 under

571591; CDL:094359-A) 

00114422 Chevron Chemical Co. (1975) The Results of Tests on the Amount of

Residue Remaining, Including a Description of the Analytical Method Used:

[Paraquat]. (Compilation; unpublished study received Feb 24, 1975 under

5F1598; CDL:094363-B) 

00114424 Chevron Chemical Co. (1975) Summary: Pasture Reseeding: [Paraquat].

(Compilation; unpublished study received Jun 9, 1975 under 5F1639;

CDL:094443-A) 
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00114426 Chevron Chemical Co. (1975) Summary of Residue Data for Field Corn

Treated with Paraquat as a Harvest-aid. (Compilation; unpublished study

received May 2, 1975 under 5F1625; CDL:094560-C) 

00114436 Chevron Chemical Co. (1962) [Study: Paraquat Residue on Almond & 

Apple Orchards]. (Compilation; unpublished study received May 8, 1963

under unknown admin. no.; CDL:119370-A) 

00114446 Chevron Chemical Co. (1970) Residue Data: [Paraquat]. (Compilation;

unpublished study received Feb 3, 1971 under 239-EX-59; CDL:122836-B) 

00114453 Chevron Chemical Co. (1964) [Residues of Paraquat in Sugar Cane and

Other Crops]. (Compilation; unpublished study received May 13, 1963

under unknown admin. no.; CDL:124215-A) 

00114464 Chevron Chemical Co. (1977) Residue Chemistry Data To Support

Amendment to Ortho Paraquat CL ... Label for Suppression and Control of

Broadleaved Weeds and Grasses in Alfalfa Seedlings. (Compilation;

unpublished study received Jul 6, 1977 under239-2186; CDL:230954-A) 

00114465 Chevron Chemical Co. (1977) Residue Chemistry Data To Support

Amendment to Ortho Paraquat CL ... Label To Add Princep as a Tank Mix

for Improved Control of Weeds and Grasses in Dormant Alfalfa. 

(Compilation; unpublished study received Apr 18, 1977 under 239-2186;

CDL:230970-A) 

00114466 Chevron Chemical Co. (1977) Residue Chemistry Data To Support

Amendment of Ortho Paraquat CL ... Label for Bermudagrass Pastures To

Add Air Applications. (Compilation; unpublished study received Nov 28,

1977 under 239-2186; CDL:232339-A) 

00114467 Chevron Chemical Co. (1977) Residue Chemistry Data To Support Label

Amendment for Ortho Paraquat CL--Ground Application for Control or

Suppression of Weeds and Grasses in Dormant Alfalfa--North Central

States, N.Y., N.J. and Pa. (Compilation; unpublished study received Jan 3,

1978 under 239-2186; CDL:232602-A) 

00114469 Chevron Chemical Co. (1977) Residue Chemistry Data To Support

Amendment to Ortho Paraquat CL ... Label To Add Louisiana and Hawaii
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for Directed Spray Kill of Weeds and Grasses in Sugarcane. (Compilation;

unpublished study received Jan 23, 1978 under 239-2186; CDL:232727-A) 

00114473 Wheeler, R. (1978) 48 Hour Acute Static Toxicity of Paraquat Dichloride

Salt (SX957) to 1st Stage Nymph Water Fleas (Daphnia magna Straus). 

(Unpublished study received Sep 15, 1978 under 239-2422; submitted by

Chevron Chemical Co., Richmond, CA; CDL:235419-A)

00114474 Florida, Dept. of Agriculture & Consumer Services (1978) Residue 

Chemistry To Support the Use of Paraquat CL on Lettuce as a

Postemergence Directed Spray. (Compilation; unpublished study received

Nov 7, 1978 under FL 78/44; CDL:236543-A) 

00117783 Chevron Chemical Co. (1970) The Results of Tests on the Amount of

Residue Remaining, Including a Description of the Analytical Methods

Used: [Paraquat]. (Compilation; unpublished study received Jun 17, 1970

under 0F0986; CDL:091698-B) 

00126096 Chevron Chemical Co. (1982) Elimination of C-14 Labeled Paraquat in

Rhesus Monkeys following a Single Parenteral Dose. (Unpublished study

received Feb 8, 1983 under 239-2186; CDL:249511-A)

00126097 Chevron Chemical Co. (1982) Percutaneous Absorption of Paraquat.

(Unpublished study received Feb 8, 1983 under 239-2186; CDL: 249511-B)

00126098 Chevron Chemical Co. (1982) Percutaneous Absorption of Paraquat. 

(Unpublished study received Feb 8, 1983 under 239-2186; CDL: 249511-C)

00126099 Chevron Chemical Co. (1982) Percutaneous Absorption of Paraquat.

(Unpublished study received Feb 8, 1983 under 239-2186; CDL: 249511-D)

00126671 Chevron Chemical Co. (1983) Residue Chemistry Data to Support a

Registration Amendment of the Paraquat CL (EPA Reg. No. 239-2186AA)

Label for Alfalfa to Reduce the Interval between Application and Harvest. 

(Compilation; unpublished study received Apr 1, 1983 under 239-2186;

CDL:249856-A)

00126783 Lindsay, S.; Banham, P.; Godley, M.; et al. (1982) Paraquat: 

Multigeneration Reproduction Study in Rats -- Three Generations: Report

No. CTL/P/ 719. (Unpublished study received April 5, 1983 under 239-
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2186; prepared by Imperial Chemical Industries PLC, U.K., submitted by

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00128221 Zapat, R.; Gonzalez-Ibanez, J. (1982) The Results of Tests on the Amount of

Paraquat Residues Remaining in or on Acerola. (Unpublished study

received Apr 25, 1983 under 239-2286; prepared by Chevron Chemical Co.

and Univ. of Puerto Rico, Agricultural Experiment Station; submitted by

Interregional Research Project No. 4, New Brunswick, NJ; CDL:071577-A) 

00128624 Chevron Chemical Co. (1982) Paraquat Alfalfa--between Cuttings--Residue

Summary: Multiple Applications. (Compilation; unpublished study received

May 19, 1983 under 239-2186; CDL:250383-B) 

00132474 Kalinowski, A.; Doe, J.; Chart, I; et al. (1983) Paraquat: 1-Year Feeding

Study in Dogs: Report NO. CTL/P/734. (Unpublished study received Oct.

24, 1983 under 239-2186; prepared by Imperial Chemical Industries PLC,

England; submitted by Chevron Chemical Co., Richmond, CA;

CDL:251668-A; 251669) 

00136330 Interregional Research Project No. 4 (1976) The Results of Tests on the

Amount of Paraquat Residues Remaining in or on Onions Including a

Description of the Analytical Methods Used. (Compilation; unpublished

study received Feb 28, 1977 under 7E1931; CDL:097509-A) 

00137859 Interregional Research Project No. 4 (1977) The Results of Tests on the

Amount of Paraquat Residues Remaining in or on Mint Including a

Description of the Analytical Method Used. (Compilation; unpublished

study received Feb 13, 1978 under 239-2186;CDL:096810-A) 

00138258 Interregional Research Project No. 4 (1976) The Results of Tests on the

Amount of Paraquat Residues Remaining in or on Strawberries Including a

Description of the Analytical Methods Used. (Compilation; unpublished

study received Aug 20, 1976 under 6E1853;CDL:072501-A) 

00138637 Woolsgrove, B.; Ashby, R.; Hepworth, P. et al. (1983) Paraquat: Combined

Toxicity and Carcinogenicity Study in Rats: LSR Report No.

82/ILY217/328. (Unpublished study received Feb. 9, 1984 under 239-2460;

prepared by Life Science Research, England; submitted by Chevron

Chemical Co., Richmond, CA.)
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00138637 Woolsgrove, B.; Ashby, R.; Hepworth, P. et al. (1983) Paraquat: Combined

Toxicity and Carcinogenicity Study in Rats: LSR Report No.

82/ILY217/328. (Unpublished study received Feb. 9, 1984 under 239-2460;

prepared by Life ScienceResearch, England; submitted by Chevron

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00139733 Chevron Chemical Company (1966) [Residue Study: Paraquat and

Gramoxone on Bananas]. (Reports by various sources; unpublished study

received Feb 21, 1967 under 7F0592; CDL:090762-A) 

00139734 Chevron Chemical Company (1966) Residue Data Sheet: Coffee: Paraquat

and Diquat Test No. T-355. (Compilation; unpublished study including test

nos. T-357, T-606, T-1092..., received Feb 21, 1967 under 7F0592;

CDL:090762-B) 

00139735 Chevron Chemical Company (1966) Residue Data Sheet: Figs: Paraquat:

Test No. T-1028. (Compilation; unpublished study including test nos.

T-1029, T-1030 and T-1031, received Feb 21, 1967 under 7F0592;

CDL:090762-C) 

00139737 Chevron Chemical Company (1966) Residue Data Sheet: Olives: Paraquat:

Test No. T-1024. (Compilation; unpublished study including test nos.

T-1025, T-1026 and T-1027, received Feb 21, 1967 under 7F0592;

CDL:090762-E) 

00139741 Chevron Chemical Company (1966) Residue Data Sheet: Lettuce: Paraquat:

Test No. T-617. (Compilation; unpublished study including test nos. T-1142

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00140828 Chevron Chemical Company (1981) Residue Data Sheet: Wheat: Paraquat

(Compilation; unpublished study, including test nos. T-5409 and T-5411,

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00147206 Chevron Chemical Co. (1985) The Results of Tests on the Amount of

Paraquat Residues Remaining in or on Pigeon Peas. Unpublished

compilation. 33 p. 

00152690 Clay, P.; Thomas, M. (1985) Assessment of Mutagenic Potential Using

L5178Y Mouse Lymphoma Cells: Paraquat Dichloride: Report No.
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00152691 Cross, M. (1985) Assessment of Mutagenic Potential Using L5178Y Mouse

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Unpublished report prepared by Imperial Chemical Industries Plc. 30 p.

00152692 Sheldon, T.; Howard, C.; Wildgoose, J.; et al. (1985) A Cytogenetic Study

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00152693 Trueman, R.; Ashby, J.; Burlison, B. (1985) Assessment for the Induction of

Unscheduled DNA Synthesis in Primary Rat Hepatocyte Cultures: Paraquat

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Imperial Chemical Industries PLC.

00152695 Howard, C.; Wildgoose, J.; Clay, P.; et al. (1985) An in vitro Sister

Chromatid Exchange Study in Chinese Hamster Lung Fibroblasts: Paraquat

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Imperial Chemical Industies PLC.

00153223 Chevron Chemical Co. (1985) Paraquat: Combined Toxigenicity and

Carcinogenicity Study in Rats: [Addendum to the Main Study: (1).

Supplementary Information on Numbers of Protocol Tissues Examined; (2).

Compilation of Tissues and Location of Lesion for All Animals with Skin

Tumors of Epithelial Origin; (3). Historical Control Data for Selected

Neoplastic Lesions; (4). Histopathological Examination of Lungs]. 

Unpublished compilation.

00153439 Wester, R.; Maibach, H.; Bucks, D.; et al. (1984) In vivo Percutaneous

Absorption of Paraquat from Hand, Leg and Forearm of Humans. Journal of

Toxicolgy and Environmental Health 14:759-762. 

00153733 Head, L.; Marsh, J.; Millward, S. (1985) Paraquat: 4 Hour Acute Inhalation

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00155289 Thompson, J. (1985) Modified Buehler Test for the Skin Sensitization

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00156313 Cox, R. (1986) Twenty-one Day Dermal Toxicity Study in Albino Rabbits

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00160000 Hutton, R.; Tucker, R.; (1984) Handbook of Toxicology of Pesticides to

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00160145 Chevron Chemical Co. (1985) Summary of Residue Data of Paraquat on

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00160250 Interregional Research Project No. 4. (1984) The Result of Tests on the

Amount of Paraquat Residues Remaining in or on Cassava, Tanier and Yam. 

Unpublished compilation. 31 p. 

00160817 Chevron Chemical Co. (1986) Residue Chemistry Data To Support a

Registration Amendment to the Paraquat+Plus Label ... To Add Fescue. 

Unpublished compilation. 32 p. 

00162736 Palmateer, S. (1980) Biological Report of Analysis: ?Toxicity Test of

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00162737 Palmateer, S. (1979) Biological Report of Analysis: ?Toxicity Test of

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00162738 McCann, J. (1977) Biological Report of Analysis: ?Toxicity Test of Ortho

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00162744 Fodre, S.; Sipos, K.; Berencisi, G. (1978) The Irritant and Allergezing

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00162870 Murray, R.; Gibson, J. (1972) A comparative study of paraquat intoxication

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00165364 Chevron Chemical Co. (1985) Residue Chemistry: Ortho Paraquat CL.

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05001991 Stevenson, J.H. (1978) The actue toxicity of unformulated pesticides to

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05008363 Hudson, R.H.; Haegele, M.A.; Tuker, R.K. (1979) Acute oral and

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Chevron Chemical Co. 11 p. 

40098001 Mayer Jr., F.; Ellersieck, M. (1986) - Manual of Acute Toxicity: 

Interpretation and Database for 410 Chemicals in 66 Species of Freshwater

Animals. U.S. Departement of Interior, Fish and Wildlife Service. 

Resource publication 160. 

40098501 Kaminski, B. (1987) Residue Chemistry Data Overview and Summary:

Paraquat Unpublished summary prepared by ICI Americas, Inc. 16 p. 

40098502 Chevron Chemical Co. (1987) Analysis of Paraquat Residues: Methods

RM-8, RM-8-9, and RM-8-10: Chevron Chemical Co. Unpublished

compilation. 22 p. 

40098503 ICI Americas Inc. (1987) Magnitude of the Residues of Paraquat in Peanuts. 

Unpublished compilation. 197 p. 

40183501 Busey, W. (1986) An Independent Pathology Review of the Lung Slides

from a Rat Chronic Toxicity/Carcinogenicity Study with Paraquat (sic):
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184

Chevron Protocol No. PQ-86-1. Unpublished study prepared by

Experimental Pathology Laboratories, Inc. 144 p.

40202401 Willis, G.A. (1987) Oncogenic Potential of Paraquat - Toxicology Data and

Overview. ICI Plant Protection Division, Fernhurst, England. Submitted by

ICI Americas Inc., Agricultural Products, Wilmington, Delaware.

40202402 Ishmael, J. (1987) Paraquat: Lifetime Feeding Study in Rats - A

Histopathological Review of Slides from the Head Region. ICI Central

Toxicology Laboratory, Alderley Park. Project No. CTL/P/1894. Submitted

by ICI Americas Inc. Agricultural Products, Wilmington, Delaware.

40202403 Toyoshima, S.; Sato, R.; Kashima, M.; and Motoyama, M. (1982) AT-5

(Paraquat) Chronic Toxicity Study Result - 104-Week Dosing Study in

Mouse. Unpublished study prepared by Nippon Experimental Medical

Research Institute, Japan.

40202404 Trueman, R.; Barber, G. (1987) Paraquat Dichloride (Technical): 

Assessment for the Induction of Unscheduled DNA Synthesis in Rat

Hepatocytes in vivo: Lab. Project ID: CTL/P/1550. Unpublished study

prepared by ICI Central Toxicology Lab.

40202405 Howard, C.; Richardson, C.; Pate, I.; et al. (1987) Paraquat Dichloride

(Technical): An Acute Cytogenetic Study in the Rat: Lab. Project ID:

CTL/P/1560. Unpublished study prepared by ICI Central Toxicology Lab. 

40218001 Toyoshima, S.; Sato, R.; Kashima, M.; et al. (1982) AT-5: Chronic

Toxicity Study Result--104 Week Dosing Study in Rat. Unpublished study

prepared by Nippon Experimental Medical Research Institute. 818p.

40479001 Eitelman, S.; Kaminski, B. (1987) Product Chemistry Registration Data

Summary and Overview. Unpublished study prepared by ICI Americas Inc. 

93 p.

40562301 Parker, S. and J.P. Leahey. 1988. Paraquat aqueous photolysis at pH 7. 

Laboratory Project No. RJ0633B. Unpublished study performed and

submitted by Zeneca Ag Products, Wilmington, DE.
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185

40624701 Eitelman, S.; Kaminski, B. (1987) Supplement to MRID#40479001: 

Product Chemistry Registration Data Summary and Overview: Paraquat. 

Unpublished study prepared by ICI Americas Inc. 9 p.

40762701 Robbins, A.J., M.C.G. Lane, and D. Riley. 1988. Paraquat: adsorption and

desorption equilibrium in soils. Laboratory Project and Report No.

RJ0662B. Unpublished study performed and submitted by ICI Americas

Inc., Wilmington, DE. 

40943701 Earl, M.; Boseley, A. (1988) The Determination of Residues of Paraquat

(PP148) in Animal Products; A High Performance Liquid Chromatographic

Method: Project ID: ICI Residue Analytical Method 4B. Unpublished study

prepared by ICI Agrochemicals. 35 p. 

40943702 Earl, M.; Boseley, A. (1988) Paraquat: Storage Stability of Residue in

Frozen Hen Muscle Tissue: Project ID: M4846B. Unpublished study

prepared by ICI Agrochemicals. 19 p. 

40943703 Earl, M.; Boseley, A. (1988) Paraquat: Storage Stability of Residues in

Frozen Eggs: Project ID: M4847B. Unpublished study prepared by ICI

Agrochemicals. 19 p. 

40943704 Earl, M.; Boseley, A. (1988) Paraquat: Residue Transfer Study with Laying

Hens Fed on a Diet Containing the Herbicide: Project ID: RJ0703B. 

Unpublished study prepared by ICI Agrochemicals. 110 p. 

41017901 Baron, J. (1989) Paraquat: Magnitude of Residue on Taro (Dryland): IR-4

PR No. 1139. Unpublished study prepared by IR-4 Western Region

Analytical Laboratory, Univ. of Hawaii. 50 p. 

41151501 Roper, E. (1989) Paraquat: Magnitude of Residues in Alfalfa Hay, Forage

and Meal: Laboratory Project ID 148-88-MR-19: Report No. TMR0014B. 

Unpublished study prepared by ICI Americas, Inc. 42 p. 

41151502 Roper, E. (1988) Paraquat: Magnitude of Residues in Fresh and Dried Figs:

Laboratory Project ID 148-88-MR-24: 148-88-MR-25. Unpublished study

prepared by ICI Americas, Inc. 47 p. 
BIBLIOGRAPHY

MRID CITATION

______________________________________________________

186

41151503 Roper, E. (1989) Paraquat: Magnitude of Residues in Cucumbers, Melons

and Summer Squash: Laboratory Project ID 148-88-MR-08: 

148-88-MR-09. Unpublished study prepared by ICI Americas, Inc. 77 p. 

41151504 Roper, E. (1988) Paraquat: Magnitude of Residues in Green Bean Hay:

Laboratory Project ID 148-88-MR-31: Report No. TMR0018B. 

Unpublished study prepared by ICI Americas, Inc. 33 p. 

41151505 Roper, E. (1988) Paraquat: Magnitude of Residues in Green Pea Hay:

Laboratory Project ID 148-88-MR-07: Report No. TMR0019B. 

Unpublished study prepared by ICI Americas, Inc. 37 p. 

41151506 Roper, E. (1988) Paraquat: Magnitude of Residues in Sweet Corn Forage

and Ears: Laboratory Project ID 148-88-MR-13: Report No. TMR0020B. 

Unpublished study prepared by ICI Americas, Inc. 50 p. 

41151507 Roper, E. (1988) Paraquat: Magnitude of Residues in Fresh Market 

Tomatoes (Exaggerated Rate): Laboratory Project ID 4-148-87-03: Report

No. TMR0021B. Unpublished study prepared by ICI Americas, Inc. 27 p. 

41151508 Roper, E. (1989) Paraquat: Magnitude of Residues in Potatoes and 

Processing Fractions: Laboratory Project ID 148-88-PR-01: Report No.

TMU0022B. Unpublished study prepared by ICI Americas, Inc. 68 p. 

41151509 Roper, E. (1989) Gramoxone Super: Residues of Paraquat in Clover Forage

and Hay: Laboratory Project ID 148-88-MR-20: Report No. TMR0023B. 

Unpublished study prepared by ICI Americas, Inc. 38 p. 

41151510 Roper, E. (1988) Paraquat: Magnitude of Residues in Whole Tomatoes and

Processing Fractions: Laboratory Project ID 148-88-PR-03: Report No,

TMR0024B. Unpublished study prepared by ICI Americas, Inc. 44 p. 

41151511 Roper, E. (1989) Stability of Weathered Residues of Paraquat on Birdsfoot

Trefoil Forage and Hay in Frozen Storage: Laboratory Project ID

PRO/R/014/88: Report No. TMR0025B. Unpublished study prepared by

ICI Americas, Inc. 22 p. 

41151512 Roper, E. (1989) Paraquat: Magnitude of Residues in Sunflower Forage and

Seeds: Laboratory Project IDs: 148-88-MR-28: 148-88-MR-30. 

Unpublished study prepared by ICI Americas, Inc. 49 p. 
BIBLIOGRAPHY

MRID CITATION

______________________________________________________

187

41151513 Roper, E. (1989) Paraquat: Magnitude of Residues in Turnip Tops: 

Laboratory Project ID 148-88-MR-04: Report No. TMR0030B. 

Unpublished study prepared by ICI Americas, Inc. 38 p. 

41151514 Roper, E. (1989) Paraquat: Magnitude of Residues in Sugarbeet Tops and

Roots: Laboratory Project ID 148-88-MR-02: Report No. TMR0031B. 

Unpublished study prepared by ICI Americas, Inc. 45 p. 

41151515 Roper, E. (1989) Paraquat: Magnitude of Residues in Grass Forage and Hay

(Eastern Pastures): Laboratory Project ID 148-88-MR-18: Report No.

TMR0032B. Unpublished study prepared by ICI Americas, Inc. 50 p. 

41151516 Roper, E. (1989) Paraquat: Magnitude of Residues in Grass Forage and Hay

(Western Use Rangeland): Laboratory Project ID 148-88-MR-17: Report

No. TMR0033B. Unpublished study prepared by ICI Americas, Inc. 37 p. 

41151517 Roper, E. (1989) Paraquat: Magnitude of Residues in Wheat Processing

Fractions: Laboratory Project ID 148-88-PR-06: Report No. TMR0034B. 

Unpublished study prepared by ICI Americas, Inc. 40 p. 

41151518 Roper, E. (1988) Paraquat: Magnitude of Residues in Sugarcane and

Processing Fractions: Laboratory Project ID 148-88-PR-11: Report No.

TMR0035B. Unpublished study prepared by ICI Americas, Inc. 32 p. 

41151519 Roper, E. (1989) Paraquat: Magnitude of Residues in Sugar Beet Processing

Fractions: Laboratory Project ID 148-88-PR-02: Report No. TMR0036B. 

Unpublished study prepared by ICI Americas, Inc. 49 p. 

41151520 Roper, E. (1989) Paraquat: Magnitude of Residues in Sorghum and

Processing Fractions: Laboratory Project ID 148-88-PR-05. Unpublished

study prepared by ICI Americas, Inc. 41 p. 

41151521 Roper, E. (1988) Paraquat: Magnitude of Residues in Hops and Processing

Fractions: Laboratory Project ID 148-88-PR-09: Report No. TMR0038B. 

Unpublished study prepared by ICI Americas, Inc. 58 p. 

41151522 Roper, E. (1988) Paraquat: Magnitude of Residues in Olives and Processing

Fractions: Project ID 148-88-PR-27. Unpublished study prepared by ICI

Americas, Inc. 41 p. 
BIBLIOGRAPHY

MRID CITATION

______________________________________________________

188

41151523 Roper, E. (1988) Paraquat: Magnitude of Residues in Field Corn Forage,

Silage, Kernels and Fodder: Project ID 4-148-87-14. Unpublished study

prepared by ICI Americas, Inc. 144 p. 

41151524 Roper, E. (1988) Paraquat: Magnitude of Residues in Soybean Forage, Hay

and Seed, Harvest Aid Use: Project ID 148-88-MR-34 and 148-88-MR-35. 

Unpublished study prepared by ICI Americas, Inc. 133 p. 

41151525 Roper, E. (1988) Paraquat: Magnitude of Residues in Wheat Forage, Straw

and Grain: Project ID 4-148-87-06. Unpublished study prepared by ICI

Americas, Inc. 95 p. 

41151526 Roper, E. (1989) Paraquat: Magnitude of Residues in Pasture Grass

(Western Use Pastures): Project ID 148-88-MR-16. Unpublished study

prepared by ICI Americas, Inc. 36 p. 

41151527 Roper, E. (1989) Paraquat: Magnitude of Residues in Soybean Forage and

Hay: Project ID 148-88-MR-33: Report No. TMR0045B. Unpublished

study prepared by ICI Americas, Inc. 46 p. 

41151528 Roper, E. (1989) Paraquat: Magnitude of Residues in Field Corn Grain and

Processing Fractions: Project ID 148-88-PR-04: Report No. TMR0046B. 

Unpublished study prepared by ICI Americas, Inc. 48 p. 

41151529 Roper, E. (1989) Paraquat: Magnitude of Residues in Coffee Beans and

Processing Fractions: Project ID 148-88-MR-22: Report No. TMR0047B. 

Unpublished study prepared by ICI Americas, Inc. 45 p. 

41151530 Roper, E. (1988) Paraquat: Magnitude of Residues in Soybean Forage, Hay

and Seed: Project ID 4-148-87-18: Report No. TMR0049B. Unpublished

study prepared by ICI Americas, Inc. 85 p. 

41151531 Roper, E. (1988) Paraquat: Magnitude of Residues in Sorghum: Project ID

4-148-87-20: Report No. TMR0050B. Unpublished study prepared by ICI

Americas, Inc. 120 p. 

41151532 Roper, E. (1988) Gramoxone Super: Residues of Paraquat in Fresh Market

and Dried Prunes: Project ID 4-148-87-05: Report No. WRC 89-120. 

Unpublished study prepared by ICI Americas, Inc. 29 p. 
BIBLIOGRAPHY

MRID CITATION

______________________________________________________

189

41151533 Roper, E. (1988) Paraquat: Residues of Paraquat in Pineapple and 

Processing Fractions, 1988: Project ID 148-88-PR-10: Report No.

TMU3658/B. Unpublished study prepared by ICI Americas, Inc. 37 p. 

41151534 Roper, E. (1988) Paraquat Residues on Pineapple Forage, 1988: Project ID

148-88-MR-14: Report No. TMU3659/B. Unpublished study prepared by

ICI Americas, Inc. 22 p. 

41151535 Roper, E. (1989) Stability of Paraquat Residues in Frozen Prune Samples:

12 Months Storage: Project ID PRO/R/010/88.: Report No. WRC 89-123. 

Unpublished study prepared by ICI Americas, Inc. 29 p. 

41151536 Roper, E. (1989) Stability of Paraquat Residues in Frozen Potato Samples:

12 Months Storage: Project ID PRO\R\009\88: Report No. TMU3662/B. 

Unpublished study prepared by ICI Americas, Inc. 28 

41151537 Roper, E. (1989) Stability of Paraquat Residues in Frozen Tomato Samples:

12 Months Storage: Project ID PRO\R\009\88: Report No. WRC 89-125. 

Unpublished study prepared by ICI Americas, Inc. 29 p. 

41151538 Roper, E. (1989) Stability of Paraquat Residues in Frozen Corn Grain

Samples: 12 Months Storage: Project ID PRO\R\010\88: Report No.

TMU3664/B. Unpublished study prepared by ICI Americas, Inc. 27 p. 

41151539 Roper, E. (1989) Stability of Paraquat Residues in Frozen Corn Fodder

Samples: 12 Months Storage: Project ID PRO\R\010\88: Report No.

TMU3665/B. Unpublished study prepared by ICI Americas, Inc. 27 p. 

41151540 Roper, E. (1989) Stability of Paraquat Residues in Frozen Corn Forage

Samples: 12 Months Storage: Project ID PRO\R\009\88: Report No.

TMC3666/B. Unpublished study prepared by ICI Americas, Inc. 27 p. 

41151541 Roper, E. (1989) Stability of Paraquat Residues in Frozen Corn Silage

Samples: 12 Months Storage: Project ID PRO\R\009\88: Report No.

TMU3667/B. Unpublished study prepared by ICI Americas, Inc. 

41151542 Roper, E. (1988) Gramoxone Super: Residues of Paraquat in Birdsfoot

Trefoil Forage and Hay, 1988: Project ID 148-88-MR-21: Report No.

TMU3672/B. Unpublished study prepared by ICI Americas, Inc. 30 p. 
BIBLIOGRAPHY

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190

41293202 Earl, M., L. Anderson, and G.T. Muir. 1989. Paraquat short term field soil

dissipation under in-use conditions in the USA (Sussex County, Delaware)

during 1987-89; analytical report. Unpublished study performed and

submitted by ICI Americas, Inc., Wilmington, DE. 

41317401 ICI Americal, Inc. (1989) Paraquat: Oncogenic Reclassification,

Toxicology Overview. Unpublished study. 

41319301 Vickers, J.A., A.D. Hurt, and D.W. Bewick. 1989. Paraquat: degradation in

aerobic soil. Laboratory Project No. 88JH386/Report No. RJ0788B. 

Unpublished study performed and submitted by ICI Americas Inc.,

Wilmington, DE. 

41319302 Vickers, J.A., A.D. Hurt, and D.W. Bewick. 1989. Paraquat: degradation in

anaerobic soil. Laboratory Project No. 88JH386/Report No. RJ0810B. 

Unpublished study performed and submitted by ICI Americas Inc.,

Wilmington, DE.

41352101 Anderson, L.; Embury, G.; Hoag, R.; et al. (1989) Paraquat: Short Term

Field Soil Dissipation Under IN-use Conditions in the USA (Pullman,

Washington) during 1987-1989: Lab Project Number: PP148BD04: Report

No. RJ0797B. Unpublished study prepared by ICI Agrochemicals. 102 p.

41352102 Anderson, L.; Embury, G.; Hoag, R. Et al. (1989) Paraquat: Short Term

Field Soil Dissipation under In-use Conditions in the USA (Clermont,

Florida) During 1987-1989: Lab Project Number: PP148BD04: Report

No. RJ0794B. Unpublished study prepared by ICI Agrochemicals. 91 p.

41645601 Vickers, J.; Hurt, A.; Bewick, D. (1990) Paraquat: Rotational Crop Study:

Lab Project Number: 88JH074. Unpublished study prepared by ICI

Agrochemicals, Jealott's Hill Research Station. 37 p. 

42217401 Sherman, M. (1992) 30-Day Response to Paraquat Dichloride Task 4:

Residue Chemistry Reregistration Standard Update. Unpublished study

prepared by ICI Americas Inc. 56 p. 

42217402 Kennedy, S. (1986) The Determination of Residues of Paraquat in Crops: A

Spectrophotometric Method: Lab Project Number: Method 1B. Unpublished

study prepared by Imperial Chemical Industries, PLC. 15 p.
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191

42217403 Kennedy, S. (1986) The Determination of Residues of Paraquat in Soil: A

Spectrophotometric Method: Lab Project Number: METHOD 2B.

Unpublished study prepared by Imperial Chemical Industries PLC. 13 p. 

42217404 Kennedy, S. (1986) The Determination of Residues of Paraquat in Liquid

Samples: A Spectrophotometric Method: Lab Project Number: METHOD

3A. Unpublished study prepared by Imperial Chemical Industries PLC. 13 p. 

42217405 Earl, M.; Boseley, A. (1988) The Determination of Residues of Paraquat in

Water and Other Liquid Samples: A Spectrophotometric Method: Lab

Project Number: METHOD 3B. Unpublished study prepared by Imperial

Chemical Industries PLC.23 p.

42217406 Roper, E. (1989) Paraquat: Magnitude of Residues in Alfalfa Hay, Forage

and Meal: Addendum to MRID 41151501: Lab Project Number: 148-88-

MR-19: TMR0014B: WRC 89-080. Unpublished study prepared by ICI

Americas, Inc. 4 p. 

42217407 Roper, E. (1988) Paraquat: Magnitude of Residues in Fresh and Dried Figs:

Addendum to MRID 41151502: Lab Project Number: 148-88-MR-24: 148-

88-MR-25: TMR0015B: WRC 89-81. Unpublished study prepared by ICI

Americas, Inc. 4 p. 

42217408 Roper, E. (1988) Paraquat: Magnitude of Residues in Cucumbers, Melons

and Summer Squash: Addendum to MRID 41151503: Lab Project Number:

148-88-MR-08/09/10: TMR0017B: WRC 89-083. Unpublished study

prepared by ICI Americas, Inc. 4 p. 

42217409 Roper, E. (1988) Paraquat: Magnitude of Residues in Green Bean Hay:

Addendum to MRID 41151504: Lab Project Number: 148-88-MR-31: WRC

89-084. Unpublished study prepared by ICI Americas, Inc. 4 p. 

42217410 Roper, E. (1988) Paraquat: Magnitude of Residues in Green Pea Hay:

Addendum to MRID 41151505: Lab Project Number: 148-88-MR-07:

TMR0019B: WRC 89-085. Unpublished study prepared by ICI Americas,

Inc. 4 p. 

42217411 Roper, E. (1988) Paraquat: Magnitude of Residues in Sweet Corn Forage

and Ears: Addendum to MRID 41151506: Lab Project Number:
BIBLIOGRAPHY

MRID CITATION

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192

TMR0020B: WRC 89-086: 148-88-MR-13. Unpublished study prepared by

ICI Americas, Inc. 4 p. 

42217412 Roper, E. (1988) Paraquat: Magnitude of Residues in Fresh Market

Tomatoes (Exaggerated Rate): Addendum to MRID 41151507: Lab Project

Number: 4-148-87-03: TMR00221B: WRC 89-087. Unpublished study

prepared by ICI Americas, Inc. 4 p. 

42217413 Roper, E. (1989) Paraquat: Magnitude of Residues in Potatoes and

Processing Fractions: Addendum to MRID 41151508: Lab Project Number:

148-88-PR-01: TMU0022B: WRC 89-088. Unpublished study prepared by

ICI Americas Inc. 5 p. 

42217414 Roper, E. (1989) Gramoxone Super: Residues of Paraquat in Clover Forage

and Hay: Addendum to MRID 41151509: Lab Project Number: 148-88-MR20: TMR0023B: WRC 89-089. Unpublished study prepared by ICI

Americas Inc. 4 p. 

42217415 Roper, E. (1988) Paraquat: Magnitude of Residues in Whole Tomatoes and

Processing Fractions: Addendum to MRID 41151510: Lab Project Number:

148-88-PR-03: TMR0024B: WRC 89-90. Unpublished study prepared by

ICI Americas Inc. 4 p. 

42217416 Roper, E. (1989) Paraquat: Magnitude of Residues in Sunflower Forage and

Seeds: Addendum to MRID 41151512: Lab Project Number: 148-88-MR28: 148-88-MR-30: TMR0029B: WRC 89-95. Unpublished study prepared

by ICI Americas Inc. 4 p. 

42217417 Roper, E. (1989) Paraquat: Magnitude of Residues in Turnip Tops: Lab

Project Number: 148-88-MR-04: TMR0030B: WRC 89-96. Unpublished

study prepared by ICI Americas Inc. 4 p. 

42217418 Roper, E. (1989) Paraquat: Magnitude of Residues in Sugarbeet Tops and

Roots: Lab Project Number: 148-88-MR-02: TMR0031B: WRC 89-97.

Unpublished study prepared by ICI Americas Inc. 4 p. 

42217419 Roper, E. (1988) Paraquat: Magnitude of Residues in Grass Forage and Hay

(Eastern Pastures): Lab Project Number: 148-88-MR-18: TMR0032B: WRC

89-98. Unpublished study prepared by ICI Americas Inc. 5 p. 
BIBLIOGRAPHY

MRID CITATION

______________________________________________________

193

42217420 Roper, E. (1989) Paraquat: Magnitude of Residues in Grass Forage and Hay

(Western Pastures): Lab Project Number: 148-88-MR-17: TMR003B: WRC

89-99. Unpublished study prepared by ICI Americas Inc. 5 p. 

42217421 Roper, E. (1989) Paraquat: Magnitude of Residues in Wheat Processing

Fractions: Lab Project Number: 148-88-PR-06: TMR0034B: WRC 89-100.

Unpublished study prepared by ICI Americas Inc. 4 p. 

42217422 Roper, E. (1988) Paraquat: Magnitude of Residues in Sugarcane and

Processing Fractions: Lab Project Number: 148-88-PR-11: TMR0035B:

WRC 89-101. Unpublished study prepared by ICI Americas Inc. 4 p. 

42217423 Roper, E. (1989) Paraquat: Magnitude of Residues in Sugarbeet Processing

Fractions: Lab Project Number: 148-88-PR-02: TMR0036B: 89-102.

Unpublished study prepared by ICI Americas Inc. 4 p. 

42217424 Roper, E. (1989) Paraquat: Magnitude of Residues in Sorghum and

Processing Fractions: Lab Project Number: 148-88-PR-05: TMR0037B:

WRC89-103. Unpublished study prepared by ICI 

42217425 Roper, E. (1989) Paraquat: Magnitude of Residues in Pasture Grass

(Western Use Pastures): Lab Project Number: 148-88-MR-16: TMR0044B:

WRC 89-110. Unpublished study prepared by ICI Americas Inc. 5 p. 

42217426 Roper, E. (1989) Paraquat: Magnitude of Residues in Soybean Forage and

Hay: Lab Project Number: 148-88-MR-3: TMR0045B: WRC 89-111.

Unpublished study prepared by ICI Americas Inc. 4 p. 

42217427 Roper, E. (1989) Paraquat: Magnitude of Residues in Field Corn Grain and

Processing Fractions: Lab Project Number: 148-88-PR-04: TMR0046B:

WRC 89-112. Unpublished study prepared by ICI Americas Inc. 4 p. 

42217428 Roper, E. (1989) Paraquat: Magnitude of Residues in Coffee Beans and

Processing Fractions: Lab Project Number: 148-88-MR-22: TMR0047B:

WRC 89-113. Unpublished study prepared by ICI Americas Inc. 4 p. 

42217429 Roper, E. (1989) Paraquat: Magnitude of Residues in Soybean Forage, Hay

and Seed: Lab Project Number: 4-148-87-18: TMR0049B: WRC 89-115.

Unpublished study prepared by ICI Americas Inc. 4 p. 
BIBLIOGRAPHY

MRID CITATION

______________________________________________________

194

42217430 Roper, E. (1989) Paraquat: Magnitude of Residues in Sorghum: Lab Project

Number: 4-148-87-20: 4-148-87-21: TMR0050B. Unpublished study

prepared by ICI Americas Inc. 5 p. 

42217431 Roper, E. (1989) Gramoxone Super: Residues of Paraquat in Fresh Market

and Dried Prunes: Lab Project Number: 4-148-87-05: TMU3657/B: WRC

89-120. Unpublished study prepared by ICI Americas Inc. 4 p. 

42217432 Roper, E. (1988) Paraquat: Residues of Paraquat in Pineapple and

Processing Fractions: Lab Project Number: 1488-88-PR-10: TMU3658/B:

WRC 89-121. Unpublished study prepared by ICI 

42217433 Roper, E. (1988) Paraquat Residues on Pineapple Forage, 1988: Lab Project

Number: 148-88-MR-14: TMU3659/B: WRC 89-122. Unpublished study

prepared by ICI Americas Inc. 4 p. 

42217434 Roper, E. (1988) Gramoxone Super: Residues of Paraquat in Birdsfoot

Trefoil Forage and Hay, 1988: Lab Project Number: 148-88-MR-21:

TMU3672/B: WRC 89-130. Unpublished study prepared by ICI Americas

Inc. 4 p. 

42217435 Roper, E. (1988) Paraquat: Magnitude of Residues in Hops and Processing

Fractions: Lab Project Number: 148-88-PR-09: TMR0038B: WRC 89-104.

Unpublished study prepared by ICI 

42217436 Roper, E. (1988) Paraquat: Residues of Paraquat from Fortified Samples of

Olives and Processed Fractions: Lab Project Number: 148-88-PR-27:

TMR0039B: WRC 89-105. Unpublished study prepared by ICI Americas

Inc. 4 p. 

42217437 Roper, E. (1988) Paraquat: Magnitude of Residues in Field Corn, Forage,

Silage Kernels and Fodder: Lab Project Number: 4-148-87-14: 148-88-MR11: TMR0040B. Unpublished study prepared by ICI Americas Inc. 5 p. 

42217438 Roper, E. (1989) Paraquat: Magnitude of Residues in Soybean Forage, Hay

and Seed Harvest Aid Use: Lab Project Number: 148-88-MR-34: 148-88-

MR-35: TMR0041B. Unpublished study prepared by ICI Americas Inc. 5 p. 
BIBLIOGRAPHY

MRID CITATION

______________________________________________________

195

42217439 Roper, E. (1988) Paraquat: Magnitude of Residues in Wheat Forage, Straw

and Grain: Lab Project Number: 4-148-87-06: 4-148-8722: 4-148-87-23.

Unpublished study prepared by ICI Americas Inc. 5 p. 

42217440 Roper, E. (1991) Stability of Paraquat Residues in Frozen Prune Samples:

25 Months Storage: Lab Project Number: PRO\R\010\88; TMR 0228B;

WRC-90-464. Unpublished study prepared by ICI Americas Inc. 38 p. 

42217441 Roper, E. (1991) Stability of Paraquat Residues in Frozen Tomato Samples:

26 Months Storage: Lab Project Number: PRO\R\009\88: TMR0226B:

WRC-90-462. Unpublished study prepared by ICI Americas Inc. 36 p. 

42217442 Roper, E. (1991) Stability of Paraquat Residues in Frozen Potato Samples:

26 Months Storage: Lab Project Number: PRO\R\009\88: TMR0227B:

WRC 90-463. Unpublished study prepared by ICI Americas Inc. 36 p. 

42217443 Roper, E. (1991) Stability of Weathered Residues of Paraquat on Birdsfoot

Trefoil Forage and Hay in Frozen Storage: Lab Project Number:

PRO\R\014\88: TMR0267B: WRC-90-549. Unpublished study prepared by

ICI Americas Inc. 27 p. 

42217444 Roper, E. (1991) Stability of Paraquat Residues in Frozen Corn Forage

Samples: 26 Months Storage: Lab Project Number: PRO\R\009\88:

TMR0234B: WRC 90-476. Unpublished study prepared by ICI Americas

Inc. 35 p. 

42217445 Roper, E. (1991) Stability of Paraquat Residues in Frozen Corn Fodder

Samples: 26 Months Storage: Lab Project Number: PRO\R\009\88:

TMR0232B: WRC-90-474. Unpublished study prepared by ICI Americas

Inc. 35 p. 

42217446 Roper, E. (1991) Stability of Paraquat Residues in Frozen Corn Silage

Samples: 26 Months Storage: Lab Project Number: PRO\R\009\88:

TMR0233B: WRC-90-475. Unpublished study prepared by ICI Americas

Inc. 35 p. 

42217447 Roper, E. (1991) Stability of Paraquat Residues in Frozen Corn Grain

Samples: 26 Months Storage: Lab Project Number: PRO\R\009\88:

TMR0231B: WRC-90-473. Unpublished study prepared 
BIBLIOGRAPHY

MRID CITATION

______________________________________________________

196

42217448 Anderson, L.; Boseley, A.; Earl, M. (1991) Paraquat: Storage Stability of

Residues in Frozen Hen Muscle Tissue: Lab Project Number: 88JH239:

RJO908B. Unpublished study prepared by ICI Americas Inc. 17 p. 

42217449 Anderson, L.; Boseley, A.; Earl, M. (1991) Paraquat: Storage Stability of

Residues in Frozen Eggs: Lab Project Number: 88JH109: RJO912B.

Unpublished study prepared by ICI Americas Inc. 17 p. 

42217450 Earl, M.; Boseley, A.; Muir, G. et al. (1991) Paraquat: Storage Stability of

the Residue in Frozen Carrot, Cabbage and Wheat Grain at <-18 Degrees

Centigrade (Interim): Lab Project Number: PP148BCO1: RJO729B.

Unpublished study prepared by ICI Americas Inc. 26 p. 

42297601 Robson, C; Nelson, N.; J.; et al. (1992) Product Chemistry Registration

Data Summary and Overview: Paraquat: (Supp. to): Lab Project Number:

P551-207. Unpublished study prepared by ICI Americas, Inc. 77 p.

42324301 Leahy, J. (1992) Overview and Summary of Paraquat Dichloride: Nature of

Residue in Plants. Unpublished study prepared by ICI Americas, Inc. 46 p. 

42324302 Leahy, J. (1992) Overview and Summary of Paraquat Dichloride: Nature of

Residue in Livestock.Unpublished study prepared by ICI Americas, Inc. 8p. 

42588201 Robson, C.; Nelson, N.; Rhodes, M. (1992) Supplement to MRID

40479001, 42297601, and 40624701: Product Chemistry Registration Data

Summary and Overview. Unpublished study prepared by ICI Americas Inc. 

26 p.

42601001 Canning, L.; White, J. (1992) Paraquat: A Glasshouse Study to Evaluate

the Effects on Vegetative Vigor of a 300 g ai litre-1 (2.5 lb ai US gal-1)

Soluble Concentrate Formulation on Terrestrial Non-Target Plants: Lab

Project Number: 92JH088: RJ1279B. Unpublished study prepared by ICI

Agrochemicals. 73 p.

42601002 Smyth, D.; Sankey, S.; Penwell, A. (1992) Paraquat Dichloride: Toxicity to

the Green Alga Selenastrum capricornutum: Lab Project Number:

BL4578/B: T168/G (FT11/92). Unpublished study prepared by Imperial

Chemical Industries PLC. 23 p.
BIBLIOGRAPHY

MRID CITATION

______________________________________________________

197

42601003 Smyth, D.; Sankey, S.; Cornish, S.; et al (1992) Paraquat Dichloride:

Toxicity to the Duckweed Lemna Gibba: Lab Project Number: BL4493/B:

T168/E (FT10/92). Unpublished study prepared by Imperial Chemical

Industries PLC. 24 p.

42601004 Smyth, D.; Sankey, S.; Penwell, A. (1992) Paraquat Dichloride: Toxicity to

the Marine Alga Skeletonema costatum: Lab Project Number: BL4580/B:

T168/C (FT08/92). Unpublished study prepared by Imperial Chemical

Industries PLC. 22 p.

42601005 Smyth, D.; Sankey, S.; Cornish, S. (1992) Paraquat Dichloride: Toxicity to

the Blue-green Alga Anabaena flos-aquae: Lab Project Number: BL4579/B:

T168/B (FT07/92). Unpublished study prepared by Imperial Chemical

Industries PLC. 26 p.

42601006 Smyth, D.; Sankey, S.; Cornish, S. (1992) Paraquat Dichloride: Toxicity to

the Freshwater diatom Navicula pelliculosa: Lab Project Number:

BL4464/B: T168/D (FT09/92). Unpublished study prepared by Imperial

Chemical Industries PLC. 22 p.

42639601 Canning, L.; White, J. (1992) Paraquat: A Glasshouse Study to Evaluate

the Effects on Seedling Emergence of a 300 g ai litre-1 (2.5 lb ai US gal-1)

Soluble Concentrate Formulation on Terrestrial Non-Target Plants: Lab

Project Number: 92JH089: RJ1280B. Unpublished study prepared by ICI

Agrochemicals. 56 p.

42670801 White, J.; Rhodes, M. (1993) Paraquat: Response to Residue Chemistry

Review of Tolerance Petition No. 5F3188. Unpublished study prepared by

Zeneca Inc. 236 p.

42684101 Rhodes, M. (1993) Paraquat: Response to Residue Chemistry Review of

Pesticide Petition No. 5F1625 and Food Additive Petition No. 5H5088. 

Unpublished study prepared by Zeneca Inc. 11 p. 

42738701 Anderson, L, R.E. Hoag, C.W. Anders, and M. Earl. 1992. Paraquat: field

soil dissipation under in-use conditions in the USA during 1987-91 (Visalia,

California). Laboratory Report No. PP148BD05/Report No. RJ1191B. 

Unpublished study performed by ICI Agrochemicals, Berkshire, UK, and

submitted by ICI Americas, Inc., Wilmington, DE.
BIBLIOGRAPHY

MRID CITATION

______________________________________________________

198

42738702 Anderson, L, R.E. Hoag, C.W. Anders, and M. Earl. 1992. Paraquat: field

soil dissipation under in-use conditions in the USA during 1987-89 (Leland,

Mississippi). Laboratory Report No. PP148BD05/Report No. RJ1206B. 

Unpublished study performed by ICI Agrochemicals, Berkshire, UK, and

submitted by ICI Americas, Inc., Wilmington, DE.

42738703 Earl, M., G.T. Emburey, J.C. Scholey and L. Anderson. 1992. Paraquat:

Storage stability of the residue in frozen soil. Laboratory Report No.

RJ1152B/Project No. PP148BC01. Unpublished study performed by ICI

Agrochemicals, Berkshire, UK, and submitted by ICI Americas, Inc.,

Wilmington, DE. 

42802101 Anderson, L, R.E. Hoag, J. Safford, C.W. Anders, and M. Earl. 1992.

Paraquat: field soil dissipation under in-use conditions in the USA during

1987-91 (Champaign, Illinois). Laboratory Report No. PP148BD05/Report

No. RJ1187B. Unpublished study performed by ICI Agrochemicals,

Berkshire, UK, and submitted by ICI Americas, Inc., Wilmington, DE.

42802102 Anderson, L, R.E. Hoag, C.W. Anders, and M. Earl. 1992. Paraquat: field

soil dissipation under in-use conditions in the USA during 1987-89

(Goldsboro, North Carolina). Laboratory Report No. PP148BD05/Report

No. RJ1146B. Unpublished study performed by ICI Agrochemicals,

Berkshire, UK, and submitted by ICI Americas, Inc., Wilmington, DE.

42961401 Rhodes, M. (1993) Response to Paraquat Dichloride Residue Chemistry

Review of ZENECA's Response to the Task 4: Reregistration Standard

Update (CBRS Nos. 9032 and 9509): Lab Project Number. Unpublished

study prepared by Zeneca Inc. 45 p.

43099701 Robson, C.; Nelson, N.; Rhodes, M. (1993) Product Chemistry Registration

Data Summary and Overview: Zeneca's Response to Agency Review

Comments Provided March 19 and November 16, 1993: Supplement to

MRID 40479001, 42297601, 40624701, and 42588201. Unpublished Study. 

31 p.

43226901 Rhodes, M. (1994) Addendum to MRID 42961401: Response to Paraquat

Dichloride Residue Chemistry Review of Zeneca's Response to the Task 4:

Reregistration Standard Update (CBRS Nos. 9032 and 9509). Unpublished

study prepared by Zeneca Inc. 6 p. 
BIBLIOGRAPHY

MRID CITATION

______________________________________________________

199

43226902 Anderson, L. (1994) PARAQUAT: Validation of a Residue Analytical

Method for the Determination of Paraquat in Animal Products: Lab Project

Number: 94JH221: RJ1600B. Unpublished study prepared by Jealotts Hill

Research Station, Zeneca Agrochemicals. 56 p. 

43226903 Coombe, N. (1994) Paraquat: Animal Tissue Method Validation--ZENECA

Agrochemicals SOP RAM/004/03: Lab Project Number: CEMS-299:

CTR-299: CEMR-299. Unpublished study prepared by Jealotts Hill

Research Station, Zeneca Agrochemicals. 88 p.

43226904 Roper, E. (1993) GRAMOXONE EXTRA: Residues of Paraquat in Soybean

Grain Dust Following Harvest Aid Application: Lab Project Number:

PARA-92-PR-01: RR 93-081B. Unpublished study prepared by Zeneca Ag

Products. 45 p. 

43429001 Nelson, N.; Li, R.; Robson, C.; et al. (1994) Supplement to MRID

40479001, 42297601, 40624701, 42588201, and 43099701: Product

Chemistry Registration Data Summary and Overview: (Paraquat

Dichloride): Project Nos. WRC-94-060; TMR0565A; PAM 658/3.

Unpublished study prepared by Zeneca, Inc. 42 p

43492601 Rhodes, M. (1994) 30-Day Response to Paraquat Dichloride Residue

Chemistry Reviews Dated May 23, 1994 and August 1, 1994 Lab Project

Number: RAM 004/05. Unpublished study prepared by Zeneca, Inc. 77 p. 

43492602 Grout, S. (1994) Paraquat: Quantification and Characterization of

Radioactive Residues in Root and Leafy Crop after Preplant Soil Treatment:

Lab Project Number: 93JH105. Unpublished study prepared by Zeneca

Agrochemicals (Zeneca Ltd). 39 p. 

43492603 Grout, S. (1994) Paraquat: Quantification and Characterization of

Radioactive Residues in Root and Oilseed Crop after Desiccant Treatment of

Foliage: Lab Project Number: 92JH243. Unpublished study prepared by

Zeneca Agrochemicals (Zeneca Limited).76p.

43618201 Rhodes, M; White J. (1995) Paraquat Dichloride; Overview of the Worker

Exposure Study during Reentry into Parqaut-Treated Cotton Fields: Lab

Project number: RRA/MER/95/0418. Unpublished study prepeared by

Zeneca Ag Products. 8 p.
BIBLIOGRAPHY

MRID CITATION

______________________________________________________

200

43618202 Iwata, T; Findlay, M. (1995) Worker Exposure During Re-Entry into

Paraquat Treated Cotton Fields; Biological Monitoring in Georgia in 1994: 

Lab project number: PARA/94/RP/01: RR/95/010B. Unpublished study

prepared by Zeneca Ag Products; Zeneca Agrochemicals, 59 p.

43644202 Meier, D. (1995) Paraquat: Worker Exposure During Mixing, Loading, and

Application of Gramoxone Extra to Pecans Using Vehicle Mounted, Ground

Boom Equipment: Lab project number: PALRA-94-AE-01: RR-019B:

CTL/P/4588. Unpublished study prepared by Zeneca Ag Products; Zeneca

Agrochemicals, 104 p.

43685001 Duerden, L. (1994) Paraquat Dichloride Technical Concentrate: Acute Oral

Toxicity to the Rat. Zeneca Central Toxicology Laboratory, UK; Report No.

CTL/ P/4424.

43685002 Duerden, L. (1994) Paraquat Dichloride Ltechnical Concentrate: Acute

Dermal Toxicity to the Rat: Lab Project Number: CTL/P/4412: CR3130. 

Unpublished study prepared by Zeneca Central Toxicology Lab. 45p.

43685003 Bugg, L. (1994) Paraquat Dichloride Technical Concentrate: Eye Irritation

to the Rabbit: Lab Project Number: CTL/P/4566: FB5012. Unpublished

study prepared by Zeneca Central Toxicology Lab. 35p.

43685004 Duerden, L. (1994) Paraquat Dichloride Technical Concentrate: Skin

Irritation to the Rabbit. Zeneca Central Toxicology Laboratory, UK; Report

No. CTL/P/4411.

43685005 Duerden, L. (1994) Paraquat Dichloride Technical Concentrate: Skin

Sensitization to the Guinea Pig. Zeneca Central Toxicology Laboratory,

UK; Report No.CTL/P/4460.

43954002 Grout, S. (1996) Representative Spectra from the Radiovalidation Study: 

(Paraquat Dichloride): Lab Project Number: RAM/001/02. Unpublished

study prepared by Zeneca Agrochemicals. 15p.
APPENDIX D. Combined Generic and Product Specific Data Call-In

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

OFFICE OF 

PREVENTION, PESTICIDES

AND TOXIC SUBSTANCES

GENERIC AND PRODUCT SPECIFIC

DATA CALL-IN NOTICE

CERTIFIED MAIL

Dear Sir or Madam:

This Notice requires you and other registrants of pesticide products containing the active

ingredient identified in Attachment A of this Notice, the Data Call-In Chemical Status Sheet,

to submit certain data as noted herein to the U.S. Environmental Protection Agency (EPA, the

Agency). These data are necessary to maintain the continued registration of your product(s)

containing this active ingredient. Within 90 days after you receive this Notice you must

respond as set forth in Section III below. Your response must state:

1. How you will comply with the requirements set forth in this Notice and its Attachments

1 through 7; or

2. Why you believe you are exempt from the requirements listed in this Notice and in

Attachment 3 (for both generic and product specific data), the Requirements Status and

Reqistrant's Response Form, (see section III-B); or

3. Why you believe EPA should not require your submission of data in the manner

specified by this Notice (see section III-D).

If you do not respond to this Notice, or if you do not satisfy EPA that you will comply with

its requirements or should be exempt or excused from doing so, then the registration of your

product(s) subject to this Notice will be subject to suspension. We have provided a list of all

of your products subject to this Notice in Attachment 2. All products are listed on both the

generic and product specific Data Call-In Response Forms. Also included is a list of all

registrants who were sent this Notice (Attachment 5).

The authority for this Notice is section 3(c)(2)(B) of the Federal Insecticide, Fungicide and

Rodenticide Act as amended (FIFRA), 7 U.S.C. section 136a(c)(2)(B). Collection of this 
202

information is authorized under the Paperwork Reduction Act by OMB Approval No.

2070-0107 and 2070-0057 (expiration date 3-31-99).

This Notice is divided into six sections and seven Attachments. The Notice itself contains

information and instructions applicable to all Data Call-In Notices. The Attachments contain

specific chemical information and instructions. The six sections of the Notice are:

Section I - Why You are Receiving this Notice

Section II - Data Required by this Notice

Section III - Compliance with Requirements of this Notice

Section IV - Consequences of Failure to Comply with this Notice

Section V - Registrants' Obligation to Report Possible Unreasonable Adverse Effects

Section VI - Inquiries and Responses to this Notice

The Attachments to this Notice are:

1 - Data Call-In Chemical Status Sheet

2 - Generic Data Call-In and Product Specific Data Call-In Response Forms with

Instructions (Form A)

3 - Generic Data Call-In and Product Specific Data Call-In Requirements Status and

Registrant's Response Forms with Instructions (Form B)

4 - EPA Batching of End-Use Products for Meeting Acute Toxicology Data

Requirements for Reregistration

5 - List of Registrants Receiving This Notice

6 - Cost Share and Data Compensation Forms

SECTION I. WHY YOU ARE RECEIVING THIS NOTICE

The Agency has reviewed existing data for this active ingredient(s) and reevaluated the

data needed to support continued registration of the subject active ingredient(s). This

reevaluation identified additional data necessary to assess the health and safety of the

continued use of products containing this active ingredient(s). You have been sent this Notice

because you have product(s) containing the subject active ingredients.

SECTION II. DATA REQUIRED BY THIS NOTICE

II-A. DATA REQUIRED

The data required by this Notice are specified in the Requirements Status and Registrant's

Response Forms: Attachment 3 (for both generic and product specific data requirements). 

Depending on the results of the studies required in this Notice, additional studies/testing may

be required.
203

II-B. SCHEDULE FOR SUBMISSION OF DATA

You are required to submit the data or otherwise satisfy the data requirements specified in

the Requirements Status and Registrant's Response Forms (Attachment 3) within the

timeframes provided.

II-C. TESTING PROTOCOL

All studies required under this Notice must be conducted in accordance with test standards

outlined in the Pesticide Assessment Guidelines for those studies for which guidelines have

been established.

These EPA Guidelines are available from the National Technical Information Service

(NTIS), Attn: Order Desk, 5285 Port Royal Road, Springfield, Va 22161 (Telephone number:

703-487-4650).

Protocols approved by the Organization for Economic Cooperation and Development

(OECD) are also acceptable if the OECD recommended test standards conform to those

specified in the Pesticide Data Requirements regulation (40 CFR § 158.70). When using the

OECD protocols, they should be modified as appropriate so that the data generated by the

study will satisfy the requirements of 40 CFR § 158. Normally, the Agency will not extend

deadlines for complying with data requirements when the studies were not conducted in

accordance with acceptable standards. The OECD protocols are available from OECD, 2001

L Street, N.W., Washington, D.C. 20036 (Telephone number 202-785-6323; Fax telephone

number 202-785-0350).

All new studies and proposed protocols submitted in response to this Data Call-In Notice

must be in accordance with Good Laboratory Practices [40 CFR Part 160].

II-D. REGISTRANTS RECEIVING PREVIOUS SECTION 3(c)(2)(B) NOTICES ISSUED

BY THE AGENCY

Unless otherwise noted herein, this Data Call-In does not in any way supersede or change

the requirements of any previous Data Call-In(s), or any other agreements entered into with

the Agency pertaining to such prior Notice. Registrants must comply with the requirements of

all Notices to avoid issuance of a Notice of Intent to Suspend their affected products.

SECTION III. COMPLIANCE WITH REQUIREMENTS OF THIS NOTICE

You must use the correct forms and instructions when completing your response to this

Notice. The type of Data Call-In you must comply with (Generic or Product Specific) is

specified in item number 3 on the four Data Call-In forms (Attachments 2 and 3).

III-A. SCHEDULE FOR RESPONDING TO THE AGENCY
204

The appropriate responses initially required by this Notice for generic and product specific

data must be submitted to the Agency within 90 days after your receipt of this Notice. Failure

to adequately respond to this Notice within 90 days of your receipt will be a basis for issuing

a Notice of Intent to Suspend (NOIS) affecting your products. This and other bases for

issuance of NOIS due to failure to comply with this Notice are presented in Section IV-A and

IV-B.

III-B. OPTIONS FOR RESPONDING TO THE AGENCY

1. Generic Data Requirements

The options for responding to this Notice for generic data requirements are: (a) voluntary

cancellation, (b) delete use(s), (c) claim generic data exemption, (d) agree to satisfy the

generic data requirements imposed by this Notice or (e) request a data waiver(s).

A discussion of how to respond if you choose the Voluntary Cancellation option, the

Delete Use(s) option or the Generic Data Exemption option is presented below. A discussion

of the various options available for satisfying the generic data requirements of this Notice is

contained in Section III-C. A discussion of options relating to requests for data waivers is

contained in Section III-D.

Two forms apply to generic data requirements, one or both of which must be used in

responding to the Agency, depending upon your response. These two forms are the

Data-Call-In Response Form, and the Requirements Status and Registrant's Response Form,

(contained in Attachments 2 and 3, respectively). 

The Data Call-In Response Forms must be submitted as part of every response to this

Notice. The Requirements Status and Registrant's Response Forms also must be submitted if

you do not qualify for a Generic Data Exemption or are not requesting voluntary cancellation

of your registration(s). Please note that the company's authorized representative is required to

sign the first page of both Data Call-In Response Forms and the Requirements Status and

Registrant's Response Forms (if this form is required) and initial any subsequent pages. The

forms contain separate detailed instructions on the response options. Do not alter the printed

material. If you have questions or need assistance in preparing your response, call or write the

contact person(s) identified in Attachment 1.

a. Voluntary Cancellation - 

You may avoid the requirements of this Notice by requesting voluntary cancellation of

your product(s) containing the active ingredient that is the subject of this Notice. If you wish

to voluntarily cancel your product, you must submit completed Generic and Product Specific

Data Call-In Response Forms (Attachment 2), indicating your election of this option.

Voluntary cancellation is item number 5 on both Data Call-In Response Form(s). If you

choose this option, these are the only forms that you are required to complete.
205

If you chose to voluntarily cancel your product, further sale and distribution of your

product after the effective date of cancellation must be in accordance with the Existing Stocks

provisions of this Notice, which are contained in Section IV-C.

b. Use Deletion - 

You may avoid the requirements of this Notice by eliminating the uses of your product to

which the requirements apply. If you wish to amend your registration to delete uses, you must

submit the Requirements Status and Reqistrant's Response Form (Attachment 3), a completed

application for amendment, a copy of your proposed amended labeling, and all other

information required for processing the application. Use deletion is option number 7 under

item 9 in the instructions for the Requirements Status and Reqistrant's Response Forms. You

must also complete a Data Call-In Response Form by signing the certification, item number 8. 

Application forms for amending registrations may be obtained from the Registration Support

Branch, Registration Division, Office of Pesticide Programs, EPA, by calling (703) 308-8358.

If you choose to delete the use(s) subject to this Notice or uses subject to specific data

requirements, further sale, distribution, or use of your product after one year from the due date

of your 90 day response, is allowed only if the product bears an amended label.

c. Generic Data Exemption - 

Under section 3(c)(2)(D) of FIFRA, an applicant for registration of a product is exempt

from the requirement to submit or cite generic data concerning an active ingredient if the

active ingredient in the product is derived exclusively from purchased, registered pesticide

products containing the active ingredient. EPA has concluded, as an exercise of its discretion,

that it normally will not suspend the registration of a product which would qualify and

continue to qualify for the generic data exemption in section 3(c)(2)(D) of FIFRA. To qualify,

all of the following requirements must be met:

(i). The active ingredient in your registered product must be present solely because of

incorporation of another registered product which contains the subject active ingredient

and is purchased from a source not connected with you;

(ii). Every registrant who is the ultimate source of the active ingredient in your product

subject to this DCI must be in compliance with the requirements of this Notice and must

remain in compliance; and

(iii). You must have provided to EPA an accurate and current "Confidential Statement of

Formula" for each of your products to which this Notice applies.

To apply for the Generic Data Exemption you must submit a completed Data Call-In

Response Form, Attachment 2 and all supporting documentation. The Generic Data

Exemption is item number 6a on the Data Call-In Response Form. If you claim a generic data
206

exemption you are not required to complete the Requirements Status and Registrant's

Response Form. Generic Data Exemption cannot be selected as an option for responding to

product specific data requirements.

If you are granted a Generic Data Exemption, you rely on the efforts of other persons to

provide the Agency with the required data. If the registrant(s) who have committed to

generate and submit the required data fail to take appropriate steps to meet requirements or

are no longer in compliance with this Data Call-In Notice, the Agency will consider that both

they and you are not compliance and will normally initiate proceedings to suspend the

registrations of both your and their product(s), unless you commit to submit and do submit the

required data within the specified time. In such cases the Agency generally will not grant a

time extension for submitting the data.

d. Satisfying the Generic Data Requirements of this Notice

There are various options available to satisfy the generic data requirements of this Notice.

These options are discussed in Section III-C.1. of this Notice and comprise options 1 through

6 of item 9 in the instructions for the Requirements Status and Registrant's Response Form

and item 6b on the Data Call-In Response Form. If you choose item 6b (agree to satisfy the

generic data requirements), you must submit the Data Call-In Response Form and the

Requirements Status and Registrant's Response Form as well as any other information/data

pertaining to the option chosen to address the data requirement. Your response must be on

the forms marked "GENERIC" in item number 3.

e. Request for Generic Data Waivers.

Waivers for generic data are discussed in Section III-D.1. of this Notice and are covered by

options 8 and 9 of item 9 in the instructions for the Requirements Status and Registrant's

Response Form. If you choose one of these options, you must submit both forms as well as

any other information/data pertaining to the option chosen to address the data requirement.

2. Product Specific Data Requirements

The options for responding to this Notice for product specific data are: (a) voluntary

cancellation, (b) agree to satisfy the product specific data requirements imposed by this

Notice or (c) request a data waiver(s).

A discussion of how to respond if you choose the Voluntary Cancellation option is

presented below. A discussion of the various options available for satisfying the product

specific data requirements of this Notice is contained in Section III-C.2. A discussion of

options relating to requests for data waivers is contained in Section III-D.2.

Two forms apply to the product specific data requirements one or both of which must be

used in responding to the Agency, depending upon your response. These forms are the

Data-Call-In Response Form, and the Requirements Status and Registrant's Response Form,
207

for product specific data (contained in Attachments 2 and 3, respectively). The Data Call-In

Response Form must be submitted as part of every response to this Notice. In addition, one

copy of the Requirements Status and Registrant's Response Form also must be submitted for

each product listed on the Data Call-In Response Form unless the voluntary cancellation

option is selected. Please note that the company's authorized representative is required to sign

the first page of the Data Call-In Response Form and Requirements Status and Reqistrant's

Response Form (if this form is required) and initial any subsequent pages. The forms contain

separate detailed instructions on the response options. Do not alter the printed material. If you

have questions or need assistance in preparing your response, call or write the contact

person(s) identified in Attachment 1.

a. Voluntary Cancellation

You may avoid the requirements of this Notice by requesting voluntary cancellation of

your product(s) containing the active ingredient that is the subject of this Notice. If you wish

to voluntarily cancel your product, you must submit a completed Data Call-In Response

Form, indicating your election of this option. Voluntary cancellation is item number 5 on both

the Generic and Product Specific Data Call-In Response Forms. If you choose this 

option, you must complete both Data Call-In response forms. These are the only forms that

you are required to complete. 

If you choose to voluntarily cancel your product, further sale and distribution of your

product after the effective date of cancellation must be in accordance with the Existing Stocks

provisions of this Notice which are contained in Section IV-C.

b. Satisfying the Product Specific Data Requirements of this Notice. 

There are various options available to satisfy the product specific data requirements of this

Notice. These options are discussed in Section III-C.2. of this Notice and comprise options 1

through 6 of item 9 in the instructions for the product specific Requirements Status and

Reqistrant's Response Form and item numbers 7a and 7b (agree to satisfy the product specific

data requirements for an MUP or EUP as applicable) on the product specific Data Call-In

Response Form. Note that the options available for addressing product specific data

requirements differ slightly from those options for fulfilling generic data requirements.

Deletion of a use(s) and the low volume/minor use option are not valid options for fulfilling

product specific data requirements. It is important to ensure that you are using the correct

forms and instructions when completing your response to the Reregistration Eligibility

Decision document.

c. Request for Product Specific Data Waivers.

Waivers for product specific data are discussed in Section III-D.2. of this Notice and are

covered by option 7 of item 9 in the instructions for the Requirements Status and Registrant's

Response Form. If you choose this option, you must submit the Data Call-In Response Form

and the Requirements Status and Registrant's Response Form as well as any other
208

information/data pertaining to the option chosen to address the data requirement. Your

response must be on the forms marked "PRODUCT SPECIFIC" in item number 3. 

III-C SATISFYING THE DATA REQUIREMENTS OF THIS NOTICE

1. Generic Data

If you acknowledge on the Generic Data Call-In Response Form that you agree to satisfy

the generic data requirements (i.e. you select item number 6b), then you must select one of the

six options on the Generic Requirements Status and Registrant's Response Form related to

data production for each data requirement. Your option selection should be entered under

item number 9, "Registrant Response." The six options related to data production are the first

six options discussed under item 9 in the instructions for completing the Requirements Status

and Registrant's Response Form. These six options are listed 

immediately below with information in parentheses to guide you to additional instructions

provided in this Section. The options are:

(1) I will generate and submit data within the specified timeframe (Developing Data)

(2) I have entered into an agreement with one or more registrants to develop data jointly

(Cost Sharing) 

(3) I have made offers to cost-share (Offers to Cost Share)

(4) I am submitting an existing study that has not been submitted previously to the

Agency by anyone (Submitting an Existing Study) 

(5) I am submitting or citing data to upgrade a study classified by EPA as partially

acceptable and upgradeable (Upgrading a Study)

(6) I am citing an existing study that EPA has classified as acceptable or an existing

study that has been submitted but not reviewed by the Agency (Citing an Existing

Study)

Option 1. Developing Data

If you choose to develop the required data it must be in conformance with Agency

deadlines and with other Agency requirements as referenced herein and in the attachments.

All data generated and submitted must comply with the Good Laboratory Practice (GLP) rule

(40 CFR Part 160), be conducted according to the Pesticide Assessment Guidelines (PAG)

and be in conformance with the requirements of PR Notice 86-5. In addition, certain studies

require Agency approval of test protocols in advance of study initiation. Those studies for

which a protocol must be submitted have been identified in the Requirements Status and

Registrant's Response Form and/or footnotes to the form. If you wish to use a protocol which

differs from the options discussed in Section II-C of this Notice, you must submit a detailed

description of the proposed protocol and your reason for wishing to use it. The Agency may

choose to reject a protocol not specified in Section II-C. If the Agency rejects your protocol

you will be notified in writing, however, you should be aware that rejection of a proposed

protocol will not be a basis for extending the deadline for submission of data.
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A progress report must be submitted for each study within 90 days from the date you are

required to commit to generate or undertake some other means to address that study

requirement, such as making an offer to cost share or agreeing to share in the cost of

developing that study. This 90-day progress report must include the date the study was or

will be initiated and, for studies to be started within 12 months of commitment, the name and

address of the laboratory(ies) or individuals who are or will be conducting the study.

In addition, if the time frame for submission of a final report is more than 1 year, interim

reports must be submitted at 12 month intervals from the date you are required to commit to

generate or otherwise address the requirement for the study. In addition to the other

information specified in the preceding paragraph, at a minimum, a brief description of current

activity on and the status of the study must be included as well as a full

description of any problems encountered since the last progress report.

The time frames in the Requirements Status and Registrant's Response Form are the time

frames that the Agency is allowing for the submission of completed study reports or

protocols. The noted deadlines run from the date of the receipt of this Notice by the registrant.

If the data are not submitted by the deadline, each registrant is subject to receipt of a Notice of

Intent to Suspend the affected registration(s).

If you cannot submit the data/reports to the Agency in the time required by this Notice and

intend to seek additional time to meet the requirements(s), you must submit a request to the

Agency which includes: (1) a detailed description of the expected difficulty and (2) a

proposed schedule including alternative dates for meeting such requirements on a step-by-step

basis. You must explain any technical or laboratory difficulties and provide documentation

from the laboratory performing the testing. While EPA is considering your request, the

original deadline remains. The Agency will respond to your request in writing. If EPA does

not grant your request, the original deadline remains. Normally, extensions can be requested

only in cases of extraordinary testing problems beyond the expectation or control of the

registrant. Extensions will not be given in submitting the 90-day responses. Extensions will

not be considered if the request for extension is not made in a timely fashion; in no event shall

an extension request be considered if it is submitted at or after the lapse of the subject

deadline.

Option 2. Agreement to Share in Cost to Develop Data

If you choose to enter into an agreement to share in the cost of producing the required data

but will not be submitting the data yourself, you must provide the name of the registrant who

will be submitting the data. You must also provide EPA with documentary evidence that an

agreement has been formed. Such evidence may be your letter offering to join in an

agreement and the other registrant's acceptance of your offer, or a written statement by the

parties that an agreement exists. The agreement to produce the data need not specify all of the

terms of the final arrangement between the parties or the mechanism to resolve the terms.
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Section 3(c)(2)(B) provides that if the parties cannot resolve the terms of the agreement they

may resolve their differences through binding arbitration.

Option 3. Offer to Share in the Cost of Data Development

If you have made an offer to pay in an attempt to enter into an agreement or amend an

existing agreement to meet the requirements of this Notice and have been unsuccessful, you

may request EPA (by selecting this option) to exercise its discretion not to suspend your

registration(s), although you do not comply with the data submission requirements of this

Notice. EPA has determined that as a general policy, absent other relevant considerations, it

will not suspend the registration of a product of a registrant who has in good faith sought and

continues to seek to enter into a joint data development/cost sharing program, but the other

registrant(s) developing the data has refused to accept the offer. To qualify for this option,

you must submit documentation to the Agency proving that you have made an offer to

another registrant (who has an obligation to submit data) to share in the burden of developing

that data. You must also submit to the Agency a completed EPA Form 8570-32, Certification

of Offer to Cost Share in the Development of Data, Attachment 7. In addition, you must

demonstrate that the other registrant to whom the offer was made has not accepted your offer

to enter into a cost-sharing agreement by including a copy of your offer and proof of the other

registrant's receipt of that offer (such as a certified mail receipt). Your offer must, in addition

to anything else, offer to share in the burden of producing the data upon terms to be agreed to

or, failing agreement, to be bound by binding arbitration as provided by FIFRA section

3(c)(2)(B)(iii) and must not qualify this offer. The other registrant must also inform EPA of its

election of an option to develop and submit the data required by this Notice by submitting a

Data Call-In Response Form and a Requirements Status and Registrant's Response Form

committing to develop and submit the data required by this Notice.

In order for you to avoid suspension under this option, you may not withdraw your offer to

share in the burden of developing the data. In addition, the other registrant must fulfill its

commitment to develop and submit the data as required by this Notice. If the other registrant

fails to develop the data or for some other reason is subject to suspension, your registration as

well as that of the other registrant normally will be subject to initiation of suspension

proceedings, unless you commit to submit, and do submit, the required data in the specified

time frame. In such cases, the Agency generally will not grant a time extension for submitting

the data.

Option 4. Submitting an Existing Study

If you choose to submit an existing study in response to this Notice, you must determine

that the study satisfies the requirements imposed by this Notice. You may only submit a study

that has not been previously submitted to the Agency or previously cited by anyone. Existing

studies are studies which predate issuance of this Notice. Do not use this option if you are

submitting data to upgrade a study. (See Option 5).
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You should be aware that if the Agency determines that the study is not acceptable, the

Agency will require you to comply with this Notice, normally without an extension of the

required date of submission. The Agency may determine at any time that a study is not valid

and needs to be repeated.

To meet the requirements of the DCI Notice for submitting an existing study, all of the

following three criteria must be clearly Met:

a. You must certify at the time that the existing study is submitted that the raw data and

specimens from the study are available for audit and review and you must identify

where they are available. This must be done in accordance with the requirements of the

Good Laboratory Practice (GLP) regulation, 40 CFR Part 160. As stated in 40 CFR

160.3 'Raw data' means any laboratory worksheets, records, memoranda, notes, or exact

copies thereof, that are the result of original observations and activities of a study and

are necessary for the reconstruction and evaluation of the report of that study. In the

event that exact transcripts of raw data have been prepared (e.g., tapes which have been

transcribed verbatim, dated, and verified accurate by signature), the exact copy or exact

transcript may be substituted for the original source as raw data. 'Raw data' may include

photographs, microfilm or microfiche copies, computer printouts, magnetic media,

including dictated observations, and recorded data from automated instruments." The

term "specimens", according to 40 CFR 160.3, means "any material derived from a test

system for examination or analysis."

b. Health and safety studies completed after May 1984 also must also contain all

GLP-required quality assurance and quality control information, pursuant to the

requirements of 40 CFR Part 160. Registrants also must certify at the time of submitting

the existing study that such GLP information is available for post May 1984 studies by

including an appropriate statement on or attached to the study signed by an authorized

official or representative of the registrant.

c. You must certify that each study fulfills the acceptance criteria for the Guideline

relevant to the study provided in the FIFRA Accelerated Reregistration Phase 3

Technical Guidance and that the study has been conducted according to the Pesticide

Assessment Guidelines (PAG) or meets the purpose of the PAG (both available from

NTIS). A study not conducted according to the PAG may be submitted to the Agency

for consideration if the registrant believes that the study clearly meets the purpose of the

PAG. The registrant is referred to 40 CFR 158.70 which states the Agency's policy

regarding acceptable protocols. If you wish to submit the study, you must, in addition to

certifying that the purposes of the PAG are met by the study, clearly articulate the

rationale why you believe the study meets the purpose of the PAG, including copies of

any supporting information or data. It has been the Agency's experience that studies

completed prior to January 1970 rarely satisfied the purpose of the PAG and that

necessary raw data usually are not available for such studies.
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If you submit an existing study, you must certify that the study meets all requirements of

the criteria outlined above.

If EPA has previously reviewed a protocol for a study you are submitting, you must

identify any action taken by the Agency on the protocol and must indicate, as part of your

certification, the manner in which all Agency comments, concerns, or issues were addressed

in the final protocol and study.

If you know of a study pertaining to any requirement in this Notice which does not meet

the criteria outlined above but does contain factual information regarding unreasonable

adverse effects, you must notify the Agency of such a study. If such study is in the Agency's

files, you need only cite it along with the notification. If not in the Agency's files, you must

submit a summary and copies as required by PR Notice 86-5.

Option 5. Upgrading a Study

If a study has been classified as partially acceptable and upgradeable, you may submit data

to upgrade that study. The Agency will review the data submitted and determine if the

requirement is satisfied. If the Agency decides the requirement is not satisfied, you may still

be required to submit new data normally without any time extension. Deficient, but

upgradeable studies will normally be classified as supplemental. However, it is important to

note that not all studies classified as supplemental are upgradeable. If you have questions

regarding the classification of a study or whether a study may be upgraded, call or write the

contact person listed in Attachment 1. If you submit data to upgrade an existing study you

must satisfy or supply information to correct all deficiencies in the study identified by EPA.

You must provide a clearly articulated rationale of how the deficiencies have been remedied

or corrected and why the study should be rated as acceptable to EPA. Your submission must

also specify the MRID number(s) of the study which you are attempting to upgrade and must

be in conformance with PR Notice 86-5.

Do not submit additional data for the purpose of upgrading a study classified as

unacceptable and determined by the Agency as not capable of being upgraded.

This option also should be used to cite data that has been previously submitted to upgrade

a study, but has not yet been reviewed by the Agency. You must provide the MRID number

of the data submission as well as the MRID number of the study being upgraded.

The criteria for submitting an existing study, as specified in Option 4 above, apply to all

data submissions intended to upgrade studies. Additionally, your submission of data intended

to upgrade studies must be accompanied by a certification that you comply with each of those

criteria, as well as a certification regarding protocol compliance with Agency 

requirements.

Option 6. Citing Existing Studies
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If you choose to cite a study that has been previously submitted to EPA, that study must

have been previously classified by EPA as acceptable, or it must be a study which has not yet

been reviewed by the Agency. Acceptable toxicology studies generally will have been

classified as "core-guideline" or "core-minimum." For ecological effects studies, the

classification generally would be a rating of "core." For all other disciplines the classification

would be "acceptable." With respect to any studies for which you wish to select this option,

you must provide the MRID number of the study you are citing and, if the study has been

reviewed by the Agency, you must provide the Agency's classification of the study.

If you are citing a study of which you are not the original data submitter, you must submit

a completed copy of EPA Form 8570-31, Certification with Respect to Data Compensation

Requirements.

2. Product Specific Data

If you acknowledge on the product specific Data Call-In Response Form that you agree to

satisfy the product specific data requirements (i.e. you select option 7a or 7b), then you must

select one of the six options on the Requirements Status and Reqistrant's Response Form

related to data production for each data requirement. Your option selection should be entered

under item number 9, "Registrant Response." The six options related to data production are

the first six options discussed under item 9 in the instructions for completing the

Requirements Status and Registrant's Response Form. These six options are listed

immediately below with information in parentheses to guide registrants to additional

instructions provided in this Section. The options are:

(1) I will generate and submit data within the specified time-frame (Developing Data)

(2) I have entered into an agreement with one or more registrants to develop data jointly

(Cost Sharing) 

(3) I have made offers to cost-share (Offers to Cost Share)

(4) I am submitting an existing study that has not been submitted previously to the

Agency by anyone (Submitting an Existing Study) 

(5) I am submitting or citing data to upgrade a study classified by EPA as partially

acceptable and upgradeable (Upgrading a Study)

(6) I am citing an existing study that EPA has classified as acceptable or an existing

study that has been

submitted but not reviewed by the Agency (Citing an Existing Study)

Option 1. Developing Data -- The requirements for developing product specific data are the

same as those described for generic data (see Section III.C.1, Option 1) except that normally

no protocols or progress reports are required.

Option 2. Agree to Share in Cost to Develop Data -- If you enter into an agreement to cost

share, the same requirements apply to product specific data as to generic data (see Section

III.C.1, Option 2). However, registrants may only choose this option for acute toxicity data

and certain efficacy data and only if EPA has indicated in the attached data tables that your
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product and at least one other product are similar for purposes of depending on

the same data. If this is the case, data may be generated for just one of the products in the

group. The registration number of the product for which data will be submitted must be noted

in the agreement to cost share by the registrant selecting this option.

Option 3. Offer to Share in the Cost of Data Development --The same requirements for

generic data (Section III.C.I., Option 3) apply to this option. This option only applies to acute

toxicity and certain efficacy data as described in option 2 above.

Option 4. Submitting an Existing Study -- The same requirements described for generic data

(see Section III.C.1., Option 4) apply to this option for product specific data.

Option 5. Upgrading a Study -- The same requirements described for generic data (see

Section III.C.1., Option 5) apply to this option for product specific data.

Option 6. Citing Existing Studies -- The same requirements described for generic data (see

Section III.C.1., Option 6) apply to this option for product specific data.

Registrants who select one of the above 6 options must meet all of the requirements

described in the instructions for completing the Data Call-In Response Form and the

Requirements Status and Registrant's Response Form, and in the generic data requirements

section (III.C.1.), as appropriate.

III-D REQUESTS FOR DATA WAIVERS

1. Generic Data

There are two types of data waiver responses to this Notice. The first is a request for a low

volume/minor use waiver and the second is a waiver request based on your belief that the data

requirement(s) are not appropriate for your product.

a. Low Volume/Minor Use Waiver

Option 8 under item 9 on the Requirements Status and Registrant's Response Form.

Section 3(c)(2)(A) of FIFRA requires EPA to consider the appropriateness of requiring

data for low volume, minor use pesticides. In implementing this provision, EPA considers

low volume pesticides to be only those active ingredients whose total 

production volume for all pesticide registrants is small. In determining whether to grant a low

volume, minor use waiver, the Agency will consider the extent, pattern and volume of use, the

economic incentive to conduct the testing, the importance of the pesticide, and the exposure

and risk from use of the pesticide. If an active ingredient is used for both high volume and

low volume uses, a low volume exemption will not be approved. If all uses of an active

ingredient are low volume and the combined volumes for all uses are also low, then an

exemption may be granted, depending on review of other information outlined below. An
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exemption will not be granted if any registrant of the active ingredient elects to conduct the

testing. Any registrant receiving a low volume minor use waiver must remain within the sales

figures in their forecast supporting the waiver request in order to remain qualified for such

waiver. If granted a waiver, a registrant will be required, as a condition of the waiver, to

submit annual sales reports. The Agency will respond to requests for waivers in writing.

To apply for a low volume, minor use waiver, you must submit the following

information, as applicable to your product(s), as part of your 90-day response to this

Notice:

(i). Total company sales (pounds and dollars) of all registered product(s) containing the

active ingredient. If applicable to the active ingredient, include foreign sales for those

products that are not registered in this country but are applied to sugar (cane or beet),

coffee, bananas, cocoa, and other such crops. Present the above information by year for

each of the past five years.

(ii) Provide an estimate of the sales (pounds and dollars) of the active ingredient for

each major use site. Present the above information by year for each of the past five years.

(iii) Total direct production cost of product(s) containing the active ingredient by year

for the past five years. Include information on raw material cost, direct labor cost,

advertising, sales and marketing, and any other significant costs listed separately.

(iv) Total indirect production cost (e.g. plant overhead, amortized plant and equipment)

charged to product(s) containing the active ingredient by year for the past five years.

Exclude all non-recurring costs that were directly related to the active ingredient, such as

costs of initial registration and any data development.

(v) A list of each data requirement for which you seek a waiver. Indicate the type of

waiver sought and the estimated cost to you (listed separately for each data requirement

and associated test) of conducting the testing needed to fulfill each of these data

requirements.

(vi) A list of each data requirement for which you are not seeking any waiver and the

estimated cost to you (listed separately for each data requirement and associated test) of

conducting the testing needed to fulfill each of these data requirements.

(vii) For each of the next ten years, a year-by-year forecast of company sales (pounds

and dollars) of the active ingredient, direct production costs of product(s) containing the

active ingredient (following the parameters in item 2 above), indirect production costs of

product(s) containing the active ingredient (following the parameters in item 3 above), and

costs of data development pertaining to the active ingredient.

(viii) A description of the importance and unique benefits of the active ingredient to

users. Discuss the use patterns and the effectiveness of the active ingredient relative to
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registered alternative chemicals and non-chemical control strategies. Focus on benefits

unique to the active ingredient, providing information that is as quantitative as possible. If

you do not have quantitative data upon which to base your estimates, then present the

reasoning used to derive your estimates. To assist the Agency in determining the degree of

importance of the active ingredient in terms of its benefits, you should provide information

on any of the following factors, as applicable to your product(s): (a) documentation of the

usefulness of the active ingredient in Integrated Pest Management, (b) description of the

beneficial impacts on the environment of use of the active ingredient, as opposed to its

registered alternatives, (c) information on the breakdown of the active ingredient after use

and on its persistence in the environment, and (d) description of its usefulness against a

pest(s) of public health significance.

Failure to submit sufficient information for the Agency to make a determination

regarding a request for a low volume/minor use waiver will result in denial of the request

for a waiver.

b. Request for Waiver of Data

Option 9, under Item 9, on the Requirements Status and Registrant's Response Form.

This option may be used if you believe that a particular data requirement should not apply

because the requirement is inappropriate. You must submit a rationale explaining why you

believe the data requirements should not apply. You also must submit the current label(s)

of your product(s) and, if a current copy of your Confidential Statement of Formula is not

already on file you must submit a current copy.

You will be informed of the Agency's decision in writing. If the Agency determines that

the data requirements of this Notice are not appropriate to your product(s), you will not be

required to supply the data pursuant to section 3(c)(2)(B). If EPA determines that the data

are required for your product(s), you must choose a method of meeting the requirements of

this Notice within the time frame provided by this Notice. Within 30 days of your receipt

of the Agency's written decision, you must submit a revised Requirements Status and

Registrant's Response Form indicating the option chosen.

2. Product Specific Data

If you request a waiver for product specific data because you believe it is inappropriate,

you must attach a complete justification for the request including technical reasons, data

and references to relevant EPA regulations, guidelines or policies. (Note: any supplemental

data must be submitted in the format required by PR Notice 86-5). This will be the only

opportunity to state the reasons or provide information in support of your request. If the

Agency approves your waiver request, you will not be required to supply the data pursuant

to section 3(c)(2)(B) of FIFRA. If the Agency denies your waiver request, you must choose

an option for meeting the data requirements of this Notice within 30 days of the receipt of

the Agency's decision. You must indicate and submit the option chosen on the product

specific Requirements Status and Registrant's Response Form. Product specific data
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requirements for product chemistry, acute toxicity and efficacy (where appropriate) are

required for all products and the Agency would grant a waiver only under extraordinary

circumstances. You should also be aware that submitting a waiver request will not

automatically extend the due date for the study in question. Waiver requests submitted

without adequate supporting rationale will be denied and the original due date will remain

in force.

SECTION IV. CONSEQUENCES OF FAILURE TO COMPLY WITH THIS NOTICE

IV-A NOTICE OF INTENT TO SUSPEND

The Agency may issue a Notice of Intent to Suspend products subject to this Notice due to

failure by a registrant to comply with the requirements of this Data Call-In Notice, pursuant to

FIFRA section 3(c)(2)(B). Events which may be the basis for issuance of a Notice of Intent to

Suspend include, but are not limited to, the following:

1. Failure to respond as required by this Notice within 90 days of your receipt of this

Notice.

2. Failure to submit on the required schedule an acceptable proposed or final protocol

when such is required to be submitted to the Agency for review.

3. Failure to submit on the required schedule an adequate progress report on a study as

required by this Notice.

4. Failure to submit on the required schedule acceptable data as required by this Notice.

5. Failure to take a required action or submit adequate information pertaining to any option

chosen to address the data requirements (e.g., any required action or information

pertaining to submission or citation of existing studies or offers, arrangements, or

arbitration on the sharing of costs or the formation of Task Forces, failure to comply

with the terms of an agreement or arbitration concerning joint data development or

failure to comply with any terms of a data waiver).

6. Failure to submit supportable certifications as to the conditions of submitted studies, as

required by Section III-C of this Notice.

7. Withdrawal of an offer to share in the cost of developing required data.

8. Failure of the registrant to whom you have tendered an offer to share in the cost of

developing data and provided proof of the registrant's receipt of such offer or failure of

a registrant on whom you rely for a generic data exemption either to:
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i. Inform EPA of intent to develop and submit the data required by this Notice on a

Data Call-In Response Form and a Requirements Status and Reqistrant's Response

Form.

ii. Fulfill the commitment to develop and submit the data as required by this Notice; or

iii. Otherwise take appropriate steps to meet the requirements stated in this Notice,

unless you commit to submit and do submit the required data in the specified time

frame.

9. Failure to take any required or appropriate steps, not mentioned above, at any time

following the issuance of this Notice.

IV-B. BASIS FOR DETERMINATION THAT SUBMITTED STUDY IS

UNACCEPTABLE

The Agency may determine that a study (even if submitted within the required time) is

unacceptable and constitutes a basis for issuance of a Notice of Intent to Suspend. The

grounds for suspension include, but are not limited to, failure to meet any of the following:

1) EPA requirements specified in the Data Call-In Notice or other documents incorporated

by reference (including, as applicable, EPA Pesticide Assessment Guidelines, Data

Reporting Guidelines, and GeneTox Health Effects Test Guidelines) regarding the design,

conduct, and reporting of required studies. Such requirements include, but are not limited

to, those relating to test material, test procedures, selection of species, number of animals,

sex and distribution of animals, dose and effect levels to be tested or attained, duration of

test, and, as applicable, Good Laboratory Practices.

2) EPA requirements regarding the submission of protocols, including the incorporation of

any changes required by the Agency following review.

3) EPA requirements regarding the reporting of data, including the manner of reporting,

the completeness of results, and the adequacy of any required supporting (or raw) data,

including, but not limited to, requirements referenced or included in this Notice or

contained in PR 86-5. All studies must be submitted in the form of a final report; a

preliminary report will not be considered to fulfill the submission requirement.

IV-C EXISTING STOCKS OF SUSPENDED OR CANCELLED PRODUCTS

EPA has statutory authority to permit continued sale, distribution and use of existing stocks

of a pesticide product which has been suspended or cancelled if doing so would be consistent

with the purposes of the Act.
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The Agency has determined that such disposition by registrants of existing stocks for a

suspended registration when a section 3(c)(2)(B) data request is outstanding generally would

not be consistent with the Act's purposes. Accordingly, the Agency anticipates granting

registrants permission to sell, distribute, or use existing stocks of suspended product(s) only in

exceptional circumstances. If you believe such disposition of existing stocks of your

product(s) which may be suspended for failure to comply with this Notice should be

permitted, you have the burden of clearly demonstrating to EPA that granting such permission

would be consistent with the Act. You also must explain why an "existing stocks" provision is

necessary, including a statement of the quantity of existing stocks and your estimate of the

time required for their sale, distribution, and use. Unless you meet this burden, the Agency

will not consider any request pertaining to the continued sale, distribution, or use of your

existing stocks after suspension.

If you request a voluntary cancellation of your product(s) as a response to this Notice and

your product is in full compliance with all Agency requirements, you will have, under most

circumstances, one year from the date your 90 day response to this Notice is due, to sell,

distribute, or use existing stocks. Normally, the Agency will allow persons other than the

registrant such as independent distributors, retailers and end users to sell, distribute or use

such existing stocks until the stocks are exhausted. Any sale, distribution or use of stocks of

voluntarily cancelled products containing an active ingredient for which the Agency has

particular risk concerns will be determined on a case-by-case basis.

Requests for voluntary cancellation received after the 90 day response period required by

this Notice will not result in the agency granting any additional time to sell, distribute, or use

existing stocks beyond a year from the date the 90 day response was due, unless you

demonstrate to the Agency that you are in full compliance with all Agency requirements,

including the requirements of this Notice. For example, if you decide to voluntarily cancel

your registration six months before a 3-year study is scheduled to be submitted, all progress

reports and other information necessary to establish that you have been conducting the study

in an acceptable and good faith manner must have been submitted to the Agency, before EPA

will consider granting an existing stocks provision.

SECTION V. REGISTRANTS' OBLIGATION TO REPORT POSSIBLE

UNREASONABLE ADVERSE EFFECTS

Registrants are reminded that FIFRA section 6(a)(2) states that if at any time after a

pesticide is registered a registrant has additional factual information regarding unreasonable

adverse effects on the environment by the pesticide, the registrant shall submit the

information to the Agency. Registrants must notify the Agency of any factual information

they have, from whatever source, including but not limited to interim or preliminary results of

studies, regarding unreasonable adverse effects on man or the environment. This requirement

continues as long as the products are registered by the Agency.
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SECTION VI. INQUIRIES AND RESPONSES TO THIS NOTICE

If you have any questions regarding the requirements and procedures established by this

Notice, call the contact person(s) listed in Attachment 1, the Data Call-In Chemical Status

Sheet.

All responses to this Notice must include completed Data Call-In Response Forms

(Attachment 2)and completed Requirements Status and Registrant's Response Forms

(Attachment 3), for both (generic and product specific data) and any other documents

required by this Notice, and should be submitted to the contact person(s) identified in

Attachment 1. If the voluntary cancellation or generic data exemption option is chosen, only

the Generic and Product Specific Data Call-In Response Forms need be submitted.

The Office of Compliance (OC) of the Office of Enforcement and Compliance Assurance

(OECA), EPA, will be monitoring the data being generated in response to this Notice.

Sincerely yours,

Lois A. Rossi, Director 

Special Review and

 Reregistration Division

Attachments

The Attachments to this Notice are:

1 - Data Call-In Chemical Status Sheet

2 - Generic Data Call-In and Product Specific Data Call-In Response Forms with

Instructions

3 - Generic Data Call-In and Product Specific Data Call-In Requirements Status and

Registrant's Response Forms with Instructions

4 - EPA Batching of End-Use Products for Meeting Acute Toxicology Data

Requirements for Reregistration

5 - List of Registrants Receiving This Notice

6 - Confidential Statement of Formula, Cost Share and Data Compensation Forms
221

Attachment 1. Chemical Status Sheets

PARAQUAT DICHLORIDE DATA CALL-IN CHEMICAL STATUS SHEET

INTRODUCTION

You have been sent this Product Specific Data Call-In Notice because you have product(s)

containing Paraquat Dichloride.

This Product Specific Data Call-In Chemical Status Sheet, contains an overview of data

required by this notice, and point of contact for inquiries pertaining to the reregistration of 0262.

This attachment is to be used in conjunction with (1) the Product Specific Data Call-In Notice,

(2) the Product Specific Data Call-In Response Form (Attachment 2), (3) the Requirements Status

and Registrant's Form (Attachment 3), (4) EPA's Grouping of End-Use Products for Meeting

Acute Toxicology Data Requirement (Attachment 4), (5) the EPA Acceptance Criteria

(Attachment 5), (6) a list of registrants receiving this DCI (Attachment 6) and (7) the Cost Share

and Data Compensation Forms in replying to this 0262 Product Specific Data Call-In

(Attachment 7). Instructions and guidance accompany each form.

DATA REQUIRED BY THIS NOTICE

The additional data requirements needed to complete the database for Paraquat Dichloride are

contained in the Requirements Status and Registrant's Response, Attachment 3. The Agency has

concluded that additional data on Paraquat Dichloride are needed for specific products. These

data are required to be submitted to the Agency within the time frame listed. These data are

needed to fully complete the reregistration of all eligible Paraquat Dichloride products.

INQUIRIES AND RESPONSES TO THIS NOTICE

If you have any questions regarding this product specific data requirements and procedures

established by this Notice, please contact Venus Eagle at (703) 308-8045.

All responses to this Notice for the Product Specific data requirements should be submitted

to:

Venus Eagle

Chemical Review Manager Team 81

Product Reregistration Branch

Special Review and Reregistration Branch 7508W

Office of Pesticide Programs

U.S. Environmental Protection Agency

Washington, D.C. 20460

RE: PARAQUAT DICHLORIDE
222

PARAQUAT DICHLORIDE DATA CALL-IN CHEMICAL STATUS SHEET

INTRODUCTION

You have been sent this Generic Data Call-In Notice because you have product(s) containing

Paraquat Dichloride.

This Generic Data Call-In Chemical Status Sheet, contains an overview of data required by

this notice, and point of contact for inquiries pertaining to the reregistration of Paraquat

Dichloride. This attachment is to be used in conjunction with (1) the Generic Data Call-In

Notice, (2) the Generic Data Call-In Response Form (Attachment 2), (3) the Requirements Status

and Registrant's Form (Attachment 2), (4) a list of registrants receiving this DCI (Attachment 4),

(5) the EPA Acceptance Criteria (Attachment 5), and (6) the Cost Share and Data Compensation

Forms in replying to this Paraquat Dichloride Generic Data Call In (Attachment F). Instructions

and guidance accompany each form.

DATA REQUIRED BY THIS NOTICE

The additional data requirements needed to complete the generic database for Paraquat

Dichloride are contained in the Requirements Status and Registrant's Response, Attachment C.

The Agency has concluded that additional product chemistry data on Paraquat Dichloride are

needed. These data are needed to fully complete the reregistration of all eligible Paraquat

Dichloride products.

INQUIRIES AND RESPONSES TO THIS NOTICE

If you have any questions regarding the generic data requirements and procedures established

by this Notice, please contact Ruby Whiters at (703) 308-8079.

All responses to this Notice for the generic data requirements should be submitted to:

Ruby Whiters, Chemical Review Manager 

Reregistration Branch 

Special Review and Registration Division (H7508W)

Office of Pesticide Programs

U.S. Environmental Protection Agency

Washington, D.C. 20460

RE: PARAQUAT DICHLORIDE
223

Attachment 2. Combined Generic and Product Specific Data Call-In Response Forms (Form A inserts) Plus Instructions

Instructions For Completing The "Data Call-In Response Forms" For The Generic And

Product Specific Data Call-In

INTRODUCTION

These instructions apply to the Generic and Product Specific "Data Call-In Response Forms"

and are to be used by registrants to respond to generic and product specific Data Call-Ins as

part of EPA's Reregistration Program under the Federal Insecticide, Fungicide, and

Rodenticide Act. If you are an end-use product registrant only and have been sent this DCI

letter as part of a RED document you have been sent just the product specific "Data Call-In

Response Forms." Only registrants responsible for generic data have been sent the generic

data response form. The type of Data Call-In (generic or product specific) is indicated in

item number 3 ("Date and Type of DCI") on each form.

Although the form is the same for both generic and product specific data, instructions for

completing these forms are different. Please read these instructions carefully before filling

out the forms.

EPA has developed these forms individually for each registrant, and has preprinted these

forms with a number of items. DO NOT use these forms for any other active ingredient.

Items 1 through 4 have been preprinted on the form. Items 5 through 7 must be completed by

the registrant as appropriate. Items 8 through 11 must be completed by the registrant before

submitting a response to the Agency.

The public reporting burden for this collection of information is estimated to average 15

minutes per response, including time for reviewing instructions, searching existing data

sources, gathering and maintaining the data needed, and completing and reviewing the

collection of information. Send comments regarding the burden estimate or any other aspect

of this collection of information, including suggestions for reducing this burden, to Chief,

Information Policy Branch, Mail Code 2136, U.S. Environmental Protection Agency, 401 M

St., S.W., Washington, D.C. 20460; and to the Office of Management and Budget, Paperwork

Reduction Project 2070-0107, Washington, D.C. 20503.
224

INSTRUCTIONS FOR COMPLETING THE DATA CALL-IN RESPONSE FORMS

Generic and Product Specific Data Call-In

Item 1. ON BOTH FORMS: This item identifies your company name, number and address.

Item 2. ON BOTH FORMS: This item identifies the case number, case name, EPA

chemical number and chemical name.

Item 3. ON BOTH FORMS: This item identifies the type of Data Call-In. The date of

issuance is date stamped.

Item 4. ON BOTH FORMS: This item identifies the EPA product registrations relevant to

the data call-in. Please note that you are also responsible for informing the Agency

of your response regarding any product that you believe may be covered by this Data

Call-In but that is not listed by the Agency in Item 4. You must bring any such

apparent omission to the Agency's attention within the period required for submission

of this response form.

Item 5. ON BOTH FORMS: Check this item for each product registration you wish to

cancel voluntarily. If a registration number is listed for a product for which you

previously requested voluntary cancellation, indicate in Item 5 the date of that

request. Since this Data Call-In requires both generic and product specific data, you

must complete item 5 on both Data Call-In response forms. You do not need to

complete any item on the Requirements Status and Registrant's Response Forms.

Item 6a. ON THE GENERIC DATA FORM: Check this Item if the Data Call-In is for

generic data as indicated in Item 3 and you are eligible for a Generic Data

Exemption for the chemical listed in Item 2 and used in the subject product. By

electing this exemption, you agree to the terms and conditions of a Generic Data

Exemption as explained in the Data Call-In Notice.

If you are eligible for or claim a Generic Data Exemption, enter the EPA registration

Number of each registered source of that active ingredient that you use in your product.

Typically, if you purchase an EPA-registered product from one or more other producers

(who, with respect to the incorporated product, are in compliance with this and any

other outstanding Data Call-In Notice), and incorporate that product into all your

products, you may complete this item for all products listed on this form. If, however,

you produce the active ingredient yourself, or use any unregistered product (regardless

of the fact that some of your sources are registered), you may not claim a Generic Data

Exemption and you may not select this item.
225

INSTRUCTIONS FOR COMPLETING THE DATA CALL-IN RESPONSE FORMS

Generic and Product Specific Data Call-In

Item 6b. ON THE GENERIC DATA FORM: Check this Item if the Data Call-In is for

generic data as indicated in Item 3 and if you are agreeing to satisfy the generic

data requirements of this Data Call-In. Attach the Requirements Status and

Registrant's Response Form that indicates how you will satisfy those

requirements.

NOTE: Item 6a and 6b are not applicable for Product Specific Data.

Item 7a. ON THE PRODUCT SPECIFIC DATA FORM: For each manufacturing use

product (MUP) for which you wish to maintain registration, you must agree to

satisfy the data requirements by responding "yes."

Item 7b. For each end use product (EUP) for which you wish to maintain registration, you

must agree to satisfy the data requirements by responding "yes." 

FOR BOTH MUP and EUP products

You should also respond "yes" to this item (7a for MUP's and 7b for EUP's) if your

product is identical to another product and you qualify for a data exemption. You must

provide the EPA registration numbers of your source(s); do not complete the

Requirements Status and Registrant's Response form. Examples of such products

include repackaged products and Special Local Needs (Section 24c) products which are

identical to federally registered products.

If you are requesting a data waiver, answer "yes" here; in addition, on the

"Requirements Status and Registrant's Response" form under Item 9, you must respond

with option 7 (Waiver Request) for each study for which you are requesting a waiver. 

NOTE: Item 7a and 7b are not applicable for Generic Data.
226

Note: You may provide additional information that does not fit on this form in a signed letter that accompanies your response. For example, you may

wish to report that your product has already been transferred to another company or that you have already voluntarily cancelled this product. For

these cases, please supply all relevant details so that EPA can ensure that its records are correct.

INSTRUCTIONS FOR COMPLETING THE DATA CALL-IN RESPONSE FORMS

Generic and Product Specific Data Call-In

Item 8. ON BOTH FORMS: This certification statement must be signed by an authorized

representative of your company and the person signing must include his/her title. 

Additional pages used in your response must be initialled and dated in the space

provided for the certification.

Item 9. ON BOTH FORMS: Enter the date of signature.

Item 10. ON BOTH FORMS: Enter the name of the person EPA should contact with

questions regarding your response.

Item 11. ON BOTH FORMS: Enter the phone number of your company contact.
227

Attachment3. Generic and Product Specific Requirement Status and Registrant's Response Forms (Form B inserts) and Instructions
228

Instructions For Completing The "Requirements Status and Registrant's Response 

Forms" For The Generic and Product Specific Data Call-In

INTRODUCTION

These instructions apply to the Generic and Product Specific "Requirements Status and

Registrant's Response Forms" and are to be used by registrants to respond to generic and

product specific Data Call-In's as part of EPA's reregistration program under the Federal

Insecticide, Fungicide, and Rodenticide Act. If you are an end-use product registrant only

and have been sent this DCI letter as part of a RED document you have been sent just the

product specific "Requirements Status and Registrant's Response Forms." Only registrants

responsible for generic data have been sent the generic data response forms. The type of

Data Call-In (generic or product specific) is indicated in item number 3 ("Date and

Type of DCI") on each form.

Although the form is the same for both product specific and generic data, instructions for

completing the forms differ slightly. Specifically, options for satisfying product specific data

requirements do not include (1) deletion of uses or (2) request for a low volume/minor use

waiver. Please read these instructions carefully before filling out the forms. 

EPA has developed these forms individually for each registrant, and has preprinted these

forms to include certain information unique to this chemical. DO NOT use these forms for

any other active ingredient.

Items 1 through 8 have been preprinted on the form. Item 9 must be completed by the

registrant as appropriate. Items 10 through 13 must be completed by the registrant before

submitting a response to the Agency. 

The public reporting burden for this collection of information is estimated to average 30

minutes per response, including time for reviewing instructions, searching existing data

sources, gathering and maintaining the data needed, and completing and reviewing the

collection of information. Send comments regarding the burden estimate or any other aspect

of this collection of information, including suggestions for reducing this burden, to Chief,

Information Policy Branch, Mail Code 2136, U.S. Environmental Protection Agency, 401 M

St., S.W., Washington, D.C. 20460; and to the Office of Management and Budget, Paperwork

Reduction Project 2070-0107, Washington, D.C. 20503.
229

INSTRUCTIONS FOR COMPLETING THE "REQUIREMENTS STATUS AND

REGISTRANT'S RESPONSE FORMS" 

Generic and Product Specific Data Call-In

Item 1. ON BOTH FORMS: This item identifies your company name, number and address.

Item 2. ON THE GENERIC DATA FORM: This item identifies the case number, case

name, EPA chemical number and chemical name.

ON THE PRODUCT SPECIFIC DATA FORM: This item identifies the case

number, case name, and the EPA Registration Number of the product for which the

Agency is requesting product specific data. 

Item 3. ON THE GENERIC DATA FORM: This item identifies the type of Data Call-In. 

The date of issuance is date stamped. 

ON THE PRODUCT SPECIFIC DATA FORM: This item identifies the type of Data

Call-In. The date of issuance is also date stamped. Note the unique identifier number

(ID#) assigned by the Agency. This ID number must be used in the transmittal

document for any data submissions in response to this Data Call-In Notice.

Item 4. ON BOTH FORMS: This item identifies the guideline reference number of studies

required. These guidelines, in addition to the requirements specified in the Data

Call-In Notice, govern the conduct of the required studies. Note that series 61 and 62

in product chemistry are now listed under 40 CFR 158.155 through 158.180, Subpart

c.

Item 5. ON BOTH FORMS: This item identifies the study title associated with the

guideline reference number and whether protocols and 1, 2, or 3-year progress

reports are required to be submitted in connection with the study. As noted in

Section III of the Data Call-In Notice, 90-day progress reports are required for all

studies.

If an asterisk appears in Item 5, EPA has attached information relevant to this guideline

reference number to the Requirements Status and Reqistrant's Response Form.
230

INSTRUCTIONS FOR COMPLETING THE "REQUIREMENTS STATUS AND

REGISTRANT'S RESPONSE FORMS" 

Generic and Product Specific Data Call-In

Item 6. ON BOTH FORMS: This item identifies the code associated with the use pattern of

the pesticide. In the case of efficacy data (product specific 

requirement), the required study only pertains to products which have the use sites

and/or pests indicated. A brief description of each code follows:

A Terrestrial food

B Terrestrial feed

C Terrestrial non-food

D Aquatic food

E Aquatic non-food outdoor

F Aquatic non-food industrial

G Aquatic non-food residential

H Greenhouse food

I Greenhouse non-food crop

J Forestry

K Residential

L Indoor food

M Indoor non-food

N Indoor medical

O Indoor residential

Item 7. ON BOTH FORMS: This item identifies the code assigned to the substance that

must be used for testing. A brief description of each code follows: 

EUP End-Use Product

MP Manufacturing-Use Product

MP/TGAI Manufacturing-Use Product and Technical Grade Active Ingredient

PAI Pure Active Ingredient

PAI/M Pure Active Ingredient and Metabolites

PAI/PAIRA Pure Active Indredient or Pute Active Ingredient Radiolabelled

PAIRA Pure Active Ingredient Radiolabelled

PAIRA/M Pure Active Ingredient Radiolabelled and Metabolites

PAIRA/PM Pure Active Ingredient Radiolabelled and Plant Metabolites

TEP Typical End-Use Product

TEP ___% Typical End-Use Product, Percent Active Ingredient Specified

TEP/MET Typical End-Use Product and Metabolites

TEP/PAI/M Typical End-Use Product or Pure Active Ingredient and Metabolites

TGAI Technical Grade Active Ingredient

TGAI/PAI Technical Grade Active Ingredient or Pure Active Ingredient
231

TGAI/PAIRA Technical Grade Active Ingredient or Pure Active Ingredient 

Radiolabelled

TGAI/TEP Technical Grade Active Ingredient or Typical End-Use Product

MET Metabolites

IMP Impurities

DEGR Degradates

* See: guideline comment

Item 8. This item completed by the Agency identifies the time frame allowed for submission

of the study or protocol identified in item 5. 

ON THE GENERIC DATA FORM: The time frame runs from the date of your

receipt of the Data Call-In notice.

ON THE PRODUCT SPECIFIC DATA FORM: The due date for submission of

product specific studies begins from the date stamped on the letter transmitting the

Reregistration Eligibility Decision document, and not from the date of receipt. 

However, your response to the Data Call-In itself is due 90 days from the date of

receipt. 

Item 9. ON BOTH FORMS: Enter the appropriate Response Code or Codes to show how

you intend to comply with each data requirement. Brief descriptions of each code

follow. The Data Call-In Notice contains a fuller description of each of these options.

Option 1. ON BOTH FORMS: (Developing Data) I will conduct a new study and

submit it within the time frames specified in item 8 above. By indicating that

I have chosen this option, I certify that I will comply with all the

requirements pertaining to the conditions for submittal of this study as

outlined in the Data Call-In Notice and that I will provide the protocols and

progress reports required in item 5 above.

Option 2. ON BOTH FORMS: (Agreement to Cost Share) I have entered into an

agreement with one or more registrants to develop data jointly. By indicating

that I have chosen this option, I certify that I will comply with all the

requirements pertaining to sharing in the cost of developing data as outlined

in the Data Call-In Notice.

However, for Product Specific Data, I understand that this option is available for

acute toxicity or certain efficacy data ONLY if the Agency indicates in an

attachment to this notice that my product is similar enough to another product to

qualify for this option. I certify that another party in the agreement is committing to

submit or provide the required data; if the required study is not submitted on time,

my product may be subject to suspension.
232

Option 3. ON BOTH FORMS: (Offer to Cost Share) I have made an offer to enter

into an agreement with one or more registrants to develop data jointly. I am

also submitting a completed "Certification of offer to Cost Share in the

Development of Data" form. I am submitting evidence that I have made an

offer to another registrant (who has an obligation to submit data) to share in

the cost of that data. I am including a copy of my offer and proof of the

other registrant's receipt of that offer. I am identifying the party which is

committing to submit or provide the required data; if the required study is

not submitted on time, my product may be subject to suspension. I

understand that other terms under Option 3 in the Data Call-In Notice apply

as well.

However, for Product Specific Data, I understand that this option is available

only for acute toxicity or certain efficacy data and only if the Agency indicates in an

attachment to this Data Call-In Notice that my product is similar enough to another

product to qualify for this option. 

Option 4. ON BOTH FORMS: (Submitting Existing Data) I will submit an existing

study by the specified due date that has never before been submitted to EPA. 

By indicating that I have chosen this option, I certify that this study meets all

the requirements pertaining to the conditions for submittal of existing data

outlined in the Data Call-In Notice and I have attached the needed

supporting information along with this response.

Option 5. ON BOTH FORMS: (Upgrading a Study) I will submit by the specified

due date, or will cite data to upgrade a study that EPA has classified as

partially acceptable and potentially upgradeable. By indicating that I have

chosen this option, I certify that I have met all the requirements pertaining to

the conditions for submitting or citing existing data to upgrade a study

described in the Data Call-In Notice. I am indicating on attached

correspondence the Master Record Identification Number (MRID) that EPA

has assigned to the data that I am citing as well as the MRID of the study I

am attempting to upgrade.

Option 6. ON BOTH FORMS: (Citing a Study) I am citing an existing study that

has been previously classified by EPA as acceptable, core, core minimum,

or a study that has not yet been reviewed by the Agency. If reviewed, I am

providing the Agency's classification of the study.

However, for Product Specific Data, I am citing another registrant's study. I

understand that this option is available ONLY for acute toxicity or certain efficacy

data and ONLY if the cited study was conducted on my product, an identical product

or a product which the Agency has "grouped" with one or more other products for

purposes of depending on the same data. I may also choose this option if I am citing

my own data. In either case, I will provide the MRID or Accession number (s). If I
233

cite another registrant's data, I will submit a completed "Certification With Respect

To Data Compensation Requirements" form.

FOR THE GENERIC DATA FORM ONLY: The following three options (Numbers

7, 8, and 9) are responses that apply only to the "Requirements Status and

Registrant's Response Form" for generic data. 

Option 7. (Deleting Uses) I am attaching an application for amendment to my

registration deleting the uses for which the data are required.

Option 8. (Low Volume/Minor Use Waiver Request) I have read the statements

concerning low volume-minor use data waivers in the Data Call-In Notice

and I request a low-volume minor use waiver of the data requirement. I am

attaching a detailed justification to support this waiver request including,

among other things, all information required to support the request. I

understand that, unless modified by the Agency in writing, the data

requirement as stated in the Notice governs.

Option 9. (Request for Waiver of Data) I have read the statements concerning data

waivers other than lowvolume minor-use data waivers in the Data Call-In

Notice and I request a waiver of the data requirement. I am attaching a

rationale explaining why I believe the data requirements do not apply. I am

also submitting a copy of my current labels. (You must also submit a copy

of your Confidential Statement of Formula if not already on file with EPA).

I understand that, unless modified by the Agency in writing, the data

requirement as stated in the Notice governs.

FOR PRODUCT SPECIFIC DATA: The following option (number 7) is a response

that applies to the "Requirements Status and Registrant's Response Form" for

product specific data. 

Option 7. (Waiver Request) I request a waiver for this study because it is

inappropriate for my product. I am attaching a complete justification for this

request, including technical reasons, data and references to relevant EPA

regulations, guidelines or policies. [Note: any supplemental data must be

submitted in the format required by P.R. Notice 86-5]. I understand that this

is my only opportunity to state the reasons or provide information in support

of my request. If the Agency approves my waiver request, I will not be

required to supply the data pursuant to Section 3(c) (2) (B) of FIFRA. If the

Agency denies my waiver request, I must choose a method of meeting the

data requirements of this Notice by the due date stated by this Notice. In this

case, I must, within 30 days-of my receipt of the Agency's written decision,

submit a revised "Requirements Status" form specifying the option chosen. I

also understand that the deadline for submission of data as specified by the

original Data Call-In notice will not change.
234

NOTE: You may provide additional information that does not fit on this form in a signed letter that accompanies this your response. For example, you

may wish to report that your product has already been transferred to another company or that you have already voluntarily cancelled this

Item 10. ON BOTH FORMS: This item must be signed by an authorized representative of

your company. The person signing must include his/her title, and must initial and

date all other pages of this form.

Item 11. ON BOTH FORMS: Enter the date of signature.

Item 12. ON BOTH FORMS: Enter the name of the person EPA should contact with

questions regarding your response.

Item 13. ON BOTH FORMS: Enter the phone number of your company contact.
235

Attachment 4. EPA Batching of End-Use Products for Meeting Data Requirements for Reregistration

EPA'S BATCHING OF PARAQUAT DICHLORIDE PRODUCTS FOR MEETING ACUTE

TOXICITY DATA REQUIREMENTS FOR REREGISTRATION

In an effort to reduce the time, resources and number of animals needed to fulfill the acute

toxicity data requirements for reregistration of products containing paraquat dichloride as the

active ingredient, the Agency has batched products which can be considered similar for

purposes of acute toxicity. Factors considered in the sorting process include each product's

active and inert ingredients (identity, percent composition and biological activity), type of

formulation (e.g., emulsifiable concentrate, aerosol, wettable powder, granular, etc.), and

labeling (e.g., signal word, use classification, precautionary labeling, etc.). Note that the

Agency is not describing batched products as "substantially similar" since some products

within a batch may not be considered chemically similar or have identical use patterns.

Using available information, batching has been accomplished by the process described in

the preceding paragraph. Notwith-standing the batching process, the Agency reserves the

right to require, at any time, acute toxicity data for an individual product should the need

arise. 

Registrants of products within a batch may choose to cooperatively generate, submit or cite

a single battery of six acute toxicological studies to represent all the products within that

batch. It is the registrants' option to participate in the process with all other registrants, only

some of the other registrants, or only their own products within a batch, or to generate all the

required acute toxicological studies for each of their own products. If a registrant chooses to

generate the data for a batch, he/she must use one of the products within the batch as the test

material. If a registrant chooses to rely upon previously submitted acute toxicity data, he/she

may do so provided that the data base is complete and valid by today's standards (see

acceptance criteria attached), the formulation tested is considered by EPA to be similar for

acute toxicity, and the formulation has not been significantly altered since submission and

acceptance of the acute toxicity data. Regardless of whether new data is generated or existing

data is referenced, registrants must clearly identify the test material by EPA Registration

Number. If more than one confidential statement of formula (CSF) exists for a product, the

registrant must indicate the formulation actually tested by identifying the corresponding CSF.

In deciding how to meet the product specific data requirements, registrants must follow the

directions given in the Data Call-In Notice and its attachments appended to the RED. The DCI

Notice contains two response forms which are to be completed and submitted to the Agency

within 90 days of receipt. The first form, "Data Call-In Response," asks whether the

registrant will meet the data requirements for each product. The second form, "Requirements

Status and Registrant's Response," lists the product specific data required for each product,

including the standard six acute toxicity tests. A registrant who wishes to participate in a

batch must decide whether he/she will provide the data or depend on someone else to do so. 

If a registrant supplies the data to support a batch of products, he/she must select one of the

following options: Developing Data (Option 1), Submitting an Existing Study (Option 4),

Upgrading an Existing Study (Option 5) or Citing an Existing Study (Option 6). If a registrant
236

depends on another's data, he/she must choose among: Cost Sharing (Option 2), Offers to

Cost Share (Option 3) or Citing an Existing Study (Option 6). If a registrant does not want to

participate in a batch, the choices are Options 1, 4, 5 or 6. However, a registrant should know

that choosing not to participate in a batch does not preclude other registrants in the batch from

citing his/her studies and offering to cost share (Option 3) those studies.

Eight products were found which contain paraquat dichloride as an active ingredient. In

addition, a number of Special Local Need (SLN) registrations based on these products were

found. The products have been placed into three batches and a "no batch" category in

accordance with the active and inert ingredients, type of formulation and current labeling.

Table 1 identifies the batched products. Table 2 lists the products which have been placed in

the "no batch" category. 

 Table 1

 Batch EPA Reg. No. % Active Ingredient Formulation Type

 1 10182-115 43.5 Liquid

10182-362 43.5 Liquid

10182-372 43.5 Liquid

NM95000300 43.5 Liquid

OK95000400 43.5 Liquid

TX95001000 43.5 Liquid

48273-6 43.5 Liquid

2 10182-111 30.3 Liquid

NC82001000 29.1 Liquid

NM94000300 30.3 Liquid

OK94000400 30.3 Liquid

SC82001100 29.1 Liquid

TX81003202 29.1 Liquid

TX93001400 29.1 Liquid

TX94001100 30.3 Liquid

TX96000500 30.3 Liquid

10182-280 37.0 Liquid
 Batch EPA Reg. No. % Active Ingredient Formulation Type

237

AL94000500 37.05 Liquid

AR95000200 37.0 Liquid

CA91002100 37.05 Liquid

CA91002200 37.05 Liquid

CA91002300 37.05 Liquid

CA91002400 37.05 Liquid

CA91003100 37.05 Liquid

CA91003600 37.05 Liquid

CA92000600 37.05 Liquid

CT90000100 37.05 Liquid

CT91000400 37.05 Liquid

DE94000200 37.0 Liquid

DE96000200 37.0 Liquid

FL90000900 37.05 Liquid

FL91000300 37.05 Liquid

FL91000600 37.05 Liquid

FL96000900 37.0 Liquid

GA94000600 37.05 Liquid

GA95000800 37.0 Liquid

HI91000100 37.05 Liquid

HI91001000 37.05 Liquid

HI92000800 37.05 Liquid

ID92001000 37.05 Liquid

ID92001100 37.05 Liquid

ID93000600 37.0 Liquid

ID95000800 37.0 Liquid
 Batch EPA Reg. No. % Active Ingredient Formulation Type

238

KY95000100 37.0 Liquid

LA94000700 37.0 Liquid

LA95000300 37.0 Liquid

MD95000100 37.0 Liquid

ME95000700 37.0 Liquid

MI91000900 37.05 Liquid

MN90000400 37.05 Liquid

MN94000600 37.05 Liquit

MO95000300 37.0 Liquid

MS95000500 37.0 Liquid

MT94000500 37.05 Liquid

NC95000300 37.0 Liquid

NC95000600 37.0 Liquid

NH90000100 37.05 Liquid

NH92000100 37.05 Liquid

NJ90000500 37.05 Liquid

NC91000200 37.05 Liquid

NV91000300 37.05 Liquid

NV93000500 37.05 Liquid

NV93000501 37.05 Liquid

OH90000600 37.0 Liquid

OH91000100 37.05 Liquid

OR91002300 37.05 Liquid

OR93000900 37.05 Liquid

OR93001900 37.05 Liquid

PA90000100 37.05 Liquid
 Batch EPA Reg. No. % Active Ingredient Formulation Type

239

PA96000400 37.0 Liquid

SC95000700 37.0 Liquid

SD94000500 37.0 Liquid

TN94000300 37.05 Liquid

TN94000800 37.0 Liquid

TN95000200 37.0 Liquid

TX90000900 37.0 Liquid

VA93000600 37.05 Liquid

VA94001200 37.0 Liquid

VA96000500 37.0 Liquid

WA91004400 37.05 Liquid

WA91004500 37.0 Liquid

WA91004800 37.05 Liquid

WA91004900 37.05 Liquid

WA93001400 37.05 Liquid

WA94003700 37.05 Liquid

WA95000700 37.0 Liquid

WI90000400 37.05 Liquid

WY95000200 37.0 Liquid

3 10182-103 23.2 Liquid

AR95000900 23.2 Liquid

LA95001500 23.2 Liquid

MS95001400 23.2 Liquid

OH88000200 23.2 Liquid

PA87000200 20.4 Liquid

TN94000700 23.2 Liquid
240

The following table lists a product that was considered not to be similar and was not placed

in any batch. The registrant of this product is responsible for meeting the acute toxicity data

requirements separately.

 Table 2 (No Batch)

EPA Reg. No. % Active Ingredient Formulation

Type

10182-120 29.42 paraquat dichloride Liquid

10.66 diuron

Products in Batch 1 may be supported by the data cited in the RED on the 45.6% technical

concentrate. Data on crystalline paraquat dichloride may be bridged to support Batch I. 

Products in Batch 2 and Batch 3 may also bridge data from Batch 1 or from the RED for

support.
241

Attachment 5. List of All Registrants Sent This Data Call-In (insert) Notice

LIST OF REGISTRANTS RECEIVING THIS DCI

(Please remove this page and insert registrants mailing list)
242
243

Attachment Cost Share, Data Compensation Forms, Confidential Statement of Formula Form and Instructions

Instructions for Completing the Confidential Statement of Formula 

The Confidential Statement of Formula (CSF) Form 8570-4 must be used. Two legible,

signed copies of the form are required. Following are basic instructions:

a. All the blocks on the form must be filled in and answered completely. 

b. If any block is not applicable, mark it N/A. 

c. The CSF must be signed, dated and the telephone number of the responsible party

must be provided.

d. All applicable information which is on the product specific data submission must also

be reported on the CSF. 

e. All weights reported under item 7 must be in pounds per gallon for liquids and

pounds per cubic feet for solids.

f. Flashpoint must be in degrees Fahrenheit and flame extension in inches. 

g. For all active ingredients, the EPA Registration Numbers for the currently registered

source products must be reported under column 12. 

h. The Chemical Abstracts Service (CAS) Numbers for all actives and inerts and all

common names for the trade names must be reported.

i. For the active ingredients, the percent purity of the source products must be reported

under column 10 and must be exactly the same as on the source product's label. 

j. All the weights in columns 13.a. and 13.b. must be in pounds, kilograms, or grams.

In no case will volumes be accepted. Do not mix English and metric system units

(i.e., pounds and kilograms). 

k. All the items under column 13.b. must total 100 percent. 

1. All items under columns 14.a. and 14.b. for the active ingredients must represent

pure active form. 

m. The upper and lower certified limits for ail active and inert ingredients must follow

the 40 CFR 158.175 instructions. An explanation must be provided if the proposed

limits are different than standard certified limits. 

n. When new CSFs are submitted and approved, all previously submitted CSFs become

obsolete for that specific formulation. 
244
245
246
247

United States Environmental Protection Agency

Washington, D.C. 20460

Certification of Offer to Cost 

Share in the Development of Data

Form Approved

OMB No. 2070-0106,

2070-0057

Approval Expires

3-31-99

Public reporting burden for this collection of information is estimated to average 15 minutes per response, including 

time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and 

completing and reviewing the collection of information. Send comments regarding the burden estimate or any other

aspect of this collection of information, including suggestions for reducing this burden to, Chief Information Policy

Branch, PM-233, U.S. Environmental Protection Agency, 401 M St., S.W., Washington, DC 20460; and to the Office of

Management and Budget, Paperwork Reduction Project (2070-0106), Washington, DC 20503.

Please fill in blanks below:

Company Name Company Number

Product Name EPA Reg. No.

I Certify that:

My company is willing to develop and submit the data required by EPA under the authority of the

Federal Insecticide, Fungicide and Rodenticide Act (FIFRA), if necessary. However my company would

prefer to enter into an agreement with one or more registrants to develop jointly or share in the cost of

developing data.

My firm has offered in writing to enter into such an agreement. That offer was irrevocable and included

an an offer to be bound by arbitration decision under section 3(c)(2)(B)(iii) of FIFRA if final agreement

on all terms could not be reached otherwise. This offer was made to the following firms on the

following date(s):

Name of Firm(s) Date of Offer

Certification:

I certify that I am duly authorized to represent the company named above, and that the statements that I have made

on this form and all attachments therein are true, accurate, and complete. I acknowledge that any knowingly false or

misleading statement may be punishable by fine or imprisonment or both under applicable law.

Signature of Company’s Authorized Representative Date

Name and Title (Please Type or Print)

EPA Form 8570-32 (5/91) Replaces EPA form 8580 which is obselete
248
249

United States Environmental Protection Agency Form Approved

Washington, DC 20460 OMB No. 2070-0107,

CERTIFICATION WITH RESPECT TO

DATA COMPENSATION REQUIREMENTS

2070-0057

Approval Expires

3-31-99

Public reporting burden for this collection of information is estimated to average 15 minutes per response, including time for 

reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the

collection of information. Send comments regarding the burden estimate or any other aspect of this collection of information, 

including suggestions for reducing this burden to, Chief Information Policy Branch, PM-233, U.S. Environmental Protection 

Agency, 401 M St., S.W., Washington, DC 20460; and to the Office of Management and Budget, Paperwork Reduction Project 

(2070-0106), Washington, DC 20503.

Please fill in blanks below.

Company Name Company Number

Product Name EPA Reg. No.

I Certify that:

1. For each study cited in support of registration or reregistratiion under the Federal Insecticide, Fungicide and Rodenticide Act 

(FIFRA) that is an exclusive use study, I am the original data submitter, or I have obtained the written permission of the original 

data submitter to cite that study.

2. That for each study cited in support of registration or reregistration under FIFRA that is NOT an exclusive use study, I am the 

original data submitter, or I have obtained the written permission of the original data submitter, or I have notified in writing the 

company(ies) that submitted data I have cited and have offered to: (a) Pay compensation for those data in accordance with sections 

3(c)(1)(F) and 3(c)(2)(D) of FIFRA; and (b) Commence negotiation to determine which data are subject to the compensation 

requirement of FIFRA and the amount of compensation due, if any. The companies I have notified are. (check one)

 [ ] The companies who have submitted the studies listed on the back of this form or attached sheets, or indicated on the attached

"Requirements Status and Registrants' Response Form,"

3. That I have previously complied with section 3(c)(1)(F) of FIFRA for the studies I have cited in support of registration or

reregistration under FIFRA.

Signature Date

Name and Title (Please Type or Print)

GENERAL OFFER TO PAY: I hereby offer and agree to pay compensation to other persons, with regard to the registration or

reregistration of my products, to the extent required by FIFRA section 3(c)(1)(F) and 3(c)(2)(D).

Signature Date

Name and Title (Please Type or Print)

EPA Form 8570-31 (4-96)
250
251

APPENDIX E. List of Available Related Documents

The following is a list of available documents for Paraquat Dichloride that my further assist

you in responding to this Reregistration Eligibility Decision document. These documents may

be obtained by the following methods:

Electronic

File format: Portable Document Format (.PDF) Requires Adobe® Acrobat or compatible

reader. Electronic copies can be downloaded from the Pesticide Special Review

and Reregistration Information System at 703-308-7224. They also are available

on the Internet on EPA's gopher server, GOPHER.EPA.GOV, or using ftp on

FTP.EPA.GOV, or using WWW (World Wide Web) on WWW.EPA.GOV., or

contact Venus Eagle at (703)-308-8045.

1. Appendix A.

2. PR Notice 86-5.

3. PR Notice 91-2 (pertains to the Label Ingredient Statement).

4. A full copy of this RED document.

5. A copy of the fact sheet for Paraquat Dichloride.

The following documents are part of the Administrative Record for Paraquat Dichloride and

may included in the EPA's Office of Pesticide Programs Public Docket. Copies of these

documents are not available electronically, but may be obtained by contacting the person listed

on the Chemical Status Sheet.

1. Health and Environmental Effects Science Chapters.

2. Detailed Label Usage Information System (LUIS) Report.

The following Agency reference documents are not available electronically, but may be

obtained by contacting the person listed on the Chemical Status Sheet of this RED document.

1. The Label Review Manual.

2. EPA Acceptance Criteria