United States       Prevention, Pesticides    EPA 738-R-01-007
Environmental Protection   and Toxic Substances    February 2002
Agency	(7508C)	
Interim Reregistration
Eligibility Decision  for
Chlorpyrifos

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               US Environmental Protection Agency
               Office of Pesticide Programs

               Reregistration Eligibility Decision
               for Chlorpyrifos
When EPA concluded the organophosphate (OP) cumulative risk assessment in July 2006, all
tolerance reassessment and reregi strati on eligibility decisions for individual OP pesticides were
considered complete. OP Interim Reregistration Eligibility Decisions (IREDs), therefore, are
considered completed REDs. OP tolerance reassessment decisions (TREDs) also are considered
completed.


Combined PDF document consists of the following:

  • Finalization of Interim Reregistration Eligibility Decisions (IREDs) and Interim Tolerance
  Reassessment and Risk Management Decisions (TREDs) for the Organophosphate Pesticides, and
  Completion of the Tolerance Reassessment and Reregistration Eligibility Process for the
  Organophosphate Pesticides (July 31, 2006)

  •  Chlorpyrifos IRED

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^ PROte
                   UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
                                 WASHINGTON D.C., 20460
                                                                     OFFICE OF
                                                            PREVENTION, PESTICIDES AND TOXIC
                                                                    SUBSTANCES
                                   MEMORANDUM
DATE:      July 31,2006

SUBJECT:  Finalization of Interim Reregi strati on Eligibility Decisions (IREDs) and Interim
             Tolerance Reassessment and Risk Management Decisions (TREDs) for the
             Organophosphate Pesticides, and Completion of the Tolerance Reassessment and
             Reregi strati on Eligibility Process for the Organophosphate Pesticides

FROM:      Debra Edwards, Director
             Special Review and Reregi strati on Division
             Office of Pesticide Programs

TO:         Jim Jones, Director
             Office of Pesticide Programs
       As you know, EPA has completed its assessment of the cumulative risks from the
Organophosphate (OP) class of pesticides as required by the Food Quality Protection Act of
1996. In addition, the individual OPs have also been subject to review through the individual-
chemical review process.  The Agency's review of individual OPs has resulted in the issuance of
Interim Reregi strati on Eligibility Decisions (IREDs) for 22 OPs, interim Tolerance
Reassessment and Risk Management Decisions (TREDs) for 8 OPs, and a Reregi strati on
Eligibility Decision (RED) for one OP, malathion.l These 31 OPs are listed in Appendix A.

       EPA has concluded, after completing its assessment of the cumulative risks associated
with exposures to all of the OPs, that:

       (1) the pesticides covered by the IREDs that were pending the results of the OP
cumulative assessment (listed in Attachment A) are indeed eligible for reregistration; and
 Malathion is included in the OP cumulative assessment. However, the Agency has issued a RED for malathion,
rather than an IRED, because the decision was signed on the same day as the completion of the OP cumulative
assessment.
                                      Page 1 of 3

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       (2) the pesticide tolerances covered by the IREDs and TREDs that were pending the
results of the OP cumulative assessment (listed in Attachment A) meet the safety standard under
Section 408(b)(2) of the FFDCA.

Thus, with regard to the OPs, EPA has fulfilled its obligations as to FFDCA tolerance
reassessment and FIFRA reregi strati on, other than product-specific reregi strati on.

       The Special Review and Reregi strati on Division will be issuing data call-in notices for
confirmatory data on two OPs, methidathion and phorate, for the reasons described in detail in
the OP cumulative assessment.  The specific studies that will be required are:

       -  28-day repeated-dose toxicity study with methidathion oxon; and
       -  Drinking water monitoring study for phorate, phorate sulfoxide, and phorate sulfone
          in both source water (at the intake) and treated water for five community water
          systems in Palm Beach County, Florida and two near Lake Okechobee, Florida.

The cumulative risk assessment and supporting documents are available on the Agency's website
at www.epa.gov/pesticides/cumulative and in the docket (EPA-HQ-OPP-2006-0618).
                                      Page 2 of 3

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                   Attachment A:
Organophosphates included in the OP Cumulative Assessment
Chemical
Acephate
Azinphos-methyl (AZM)
Bensulide
Cadusafos
Chlorethoxyphos
Chlorpyrifos
Coumaphos
DDVP (Dichlorvos)
Diazinon
Dicrotophos
Dimethoate
Disulfoton
Ethoprop
Fenitrothion
Malathion
Methamidophos
Methidathion
Methyl Parathion
Naled
Oxydemeton-methyl
Phorate
Phosalone
Phosmet
Phostebupirim
Pirimiphos-methyl
Profenofos
Propetamphos
Terbufos
Tetrachlorvinphos
Tribufos
Trichlorfon
Decision Document
IRED
IRED
IRED
TRED
TRED
IRED
TRED
IRED
IRED
IRED
IRED
IRED
IRED
TRED
RED
IRED
IRED
IRED
IRED
IRED
IRED
TRED
IRED
TRED
IRED
IRED
IRED
IRED
TRED
IRED
TRED
Status
IRED completed 9/2001
IRED completed 10/2001
IRED completed 9/2000
TRED completed 9/2000
TRED completed 9/2000
IRED completed 9/2001
TRED completed 2/2000
IRED completed 6/2006
IRED completed 7/2002
IRED completed 4/2002
IRED completed 6/2006
IRED completed 3/2002
IRED completed 9/2001
IRED addendum completed 2/2006
TRED completed 10/2000
RED completed 8/2006
IRED completed 4/2002
IRED completed 4/2002
IRED completed 5/2003
IRED completed 1/2002
IRED completed 8/2002
IRED completed 3/2001
TRED completed 1/2001
IRED completed 10/2001
TRED completed 12/2000
IRED completed 6/2001
IRED completed 9/2000
IRED completed 12/2000
IRED completed 9/2001
TRED completed 12/2002
IRED completed 12/2000
TRED completed 9/2001
                     Page 3 of 3

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              United States
              Environmental Protection
              Agency
Prevention, Pesticides
and Toxic Substances
(7508C)
EPA 738-F-01-006
February 2002
                 Chlorpyrifos  Facts
       EPA has assessed the risks of chlorpyrifos and reached an Interim Reregistration Eligibility
Decision (IRED) for this organophosphate (OP) pesticide. Provided that risk mitigation measures are
adopted, chlorpyrifos fits into its own "risk cup"-- its individual, aggregate risks are within acceptable
levels.  Chlorpyrifos also is eligible for reregistration, pending a full reassessment of the cumulative
risk from all OPs.
       Used on a variety of food and feed crops,
golf courses, as a non-structural wood treatment, and
as an adult mosquitocide, chlorpyrifos residues in
food and drinking water do not pose risk concerns.
With mitigation eliminating virtually all homeowner
uses, chlorpyrifos fits into its own "risk cup."  With
other mitigation measures, chlorpyrifos worker and
ecological risks also will be below levels of concern
for reregistration.

       EPA's next step under the Food Quality
Protection Act (FQPA) is to complete a cumulative
risk assessment and risk management decision
encompassing all the OP pesticides, which share a
common mechanism of toxicity.  The interim
decision on chlorpyrifos cannot be considered final
until this cumulative assessment is complete.
Further risk mitigation may be warranted at that
time.
       EPA is reviewing the OP pesticides to
determine whether they meet current health and
safely standards.  Older OPs need decisions about
their eligibility for reregistration under FIFRA. OPs
with residues in food, drinking water, and other non-
occupational exposures also must be reassessed to make sure they meet the new FQPA safety
standard.
           The OP Pilot Public Participation Process

                The organophosphates are a group of
         related pesticides that affect the functioning of the
         nervous system. They are among EPA's highest
         priority for review under the Food Quality
         Protection Act.
                EPA is encouraging the public to
         participate in the review of the OP pesticides.
         Through a six-phased pilot public participation
         process, the Agency is releasing for review and
         comment its preliminary and revised scientific risk
         assessments for individual OPs.  (Please contact
         the OP Docket,  telephone 703-305-5805, or see
         EPA's web site, www.epa.gov/pesticides/op .)
                EPA is exchanging  information with
         stakeholders and the public about the OPs, their
         uses, and risks through Technical Briefings,
         stakeholder meetings, and other fora.  USDA is
         coordinating input from growers and other OP
         pesticide users.
                Based on current information from
         interested stakeholders and the public, EPA is
         making interim risk management decisions for
         individual OP pesticides, and will  make final
         decisions through a cumulative OP assessment.
       The chlorpyrifos interim decision was made through the OP pilot public participation process,
which increases transparency and maximizes stakeholder involvement in EPA's development of risk
assessments and risk management decisions. EPA worked extensively with affected parties to reach

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the decisions presented in this interim decision document, which concludes the OP pilot process for
chlorpyrifos.
Uses
       Chlorpyrifos is an organophosphate insecticide, acaricide and miticide used to control foliage
       and soil-borne insect pests on a variety of food and feed crops.

       Approximately 10 million pounds are applied annually in agricultural settings.  The largest
       agricultural market for chlorpyrifos in terms of total pounds ai is corn (-5.5 million).
Health Effects
Risks
       Chlorpyrifos can cause cholinesterase inhibition in humans;  that is, it can overstimulate the
       nervous system causing nausea, dizziness, confusion, and at very high exposures (e.g.,
       accidents or major spills), respiratory paralysis and death.
       Dietary exposures from eating food crops treated with chlorpyrifos are below the level of
       concern for the entire U.S. population, including infants and children. Drinking water risk
       estimates based on screening models and monitoring data from both ground and surface water
       for acute and chronic exposures are generally not of concern.

       In June, 2000, the Agency entered into an agreement with the technical registrants to
       eliminate virtually all homeowner uses, except ant and roach baits in child resistent
       packaging.

       Residential postapplication exposures may occur after termiticide use in residential structures.
       To mitigate risks from this use, the technical registrants agreed in June 2000 to limit
       termiticide treatments to 0.5% solution, and cancel all postconstruction uses.  Pre-construction
       use will remain until 2005, unless acceptable exposure data are submitted that show that
       residential postapplication risks from this use are not a concern.

       Occupational exposure to chlorpyrifos is of concern to the Agency.  Exposures of concern
       include mixing/loading liquids for aerial/chemigation and groundboom application, mixing
       wettable powder for groundboom application,  aerial application,  and application by backpack
       sprayer, high-pressure handwand, and hand-held sprayer or duster. Generally, these risks can
       be mitigated by a combination of additional personal protective equipment and engineering
       controls, and by reductions in application rates. Additionally, the Agricultural Handler Task
       Force will be developing exposure  data to better characterize the risk from certain uses (e.g.,
       applying granulars by air).

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•      Risk quotients indicate that a single application of chlorpyrifos poses risks to small mammals,
       birds, fish and aquatic invertebrate species for nearly all registered outdoor uses. Multiple
       applications increase the risks to wildlife and prolong exposures to toxic concentrations. To
       address these risks, a number of measures including reduced application rates, increased
       retreatment intervals, reduced seasonal maximum amounts applied per acre, and no-spray
       setback zones around water bodies will be needed.

Risk Mitigation

       In order to support a reregistration eligibility decision for chlorpyrifos, the following risk
mitigation measures are necessary:

       To mitigate risks to agricultural workers PPE consisting of double layers, chemical resistant
       gloves, chemical resistant shoes plus socks, chemical resistant headgear for overhead
       exposure, chemical resistant apron when cleaning and mixing or loading and a dust/mist
       respirator are required for the following scenarios: mixing/loading liquids for groundboom
       and airblast application, loading granulars for ground application, tractor drawn granular
       spreader, and low pressure handwand.

•      engineering controls are required for the following scenarions: mixing wettable powder for
       groundboom application (water soluble packaging), mixing wettable powder for airblast
       application (water soluble packaging), and aerial application of sprays (enclosed cockpit).

•      There are still some occupational risk scenarios that are still below the target MOE of 100,
       even with all feasible PPE or engineering controls. The risk assessments for these uses will
       be refined with additional data.

       To mitigate ecological risks the technical registrants have agreed to label amendments which
       include the use of buffer zones to protect water quality, fish and wildlife, reductions in
       application rates, number of applications per season, seasonal maximum amounts applied, and
       increases in the minimum intervals for retreatment.

•      The mitigation measures prescribed in the IRED along with mitigation that is already being
       implemented as a result of the June, 2000, Memorandum of Agreement, will reduce risk to
       both terrestrial and aquatic species. For example, many of the reported incidents of wildlife
       mortality associated with chlorpyrifos use were related to residential  lawn and termite uses
       and use on golf courses. The residential uses have been eliminated, the termiticide use is
       being phased out, and the application rate on golf courses has been reduced from 4 to 1
       Ib/ai/A. Additionally, no-spray buffers around  surface water bodies, as well as rate
       reductions for agricultural uses will be implemented as a result of this IRED and will further
       reduce the environmental burden of chlorpyrifos.

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Next Steps
       Numerous opportunities for public comment were offered as this decision was being
       developed.  In addition, the chlorpyrifos IRED has been issued with a public comment period
       (see www.epa.gov/REDs/ or www.epa.gov/pesticides/op).

       When the cumulative risk assessment for all organophosphate pesticides is completed, EPA
       will issue its final tolerance reassessment decision for chlorpyrifos and may request further
       risk mitigation measures. The Agency will revoke the tomato tolerance and amend the grape
       and apple tolerances for chlorpyrifos. For all OPs, raising and/or establishing tolerances will
       be considered once a cumulative assessment is completed.

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           S UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
          f                           WASHINGTON, D.C. 20460
                                                                            OFFICE OF
                                                                       PREVENTION, PESTICIDES
                                                                       AND TOXIC SUBSTANCES
CERTIFIED MAIL

Dear Registrant:

     This is to inform you that the Environmental Protection Agency (hereafter referred to as
EPA or the Agency) has completed its review of the available data and public comments
received related to the preliminary and revised risk assessments for the organophosphate
pesticide chlorpyrifos. The public comment period on the revised risk assessment phase of the
reregi strati on process is closed. Based on comments received during the public comment period
and additional data received from the technical registrants, the Agency revised the human health
and environmental effects risk assessments and made them available to the public on August 16,
2000. Additionally, the Agency held a Technical Briefing on June 8, 2000, where the results of
the revised human health and environmental effects risk assessments and interim mitigation
measures were presented to the general public. This Technical Briefing concluded Phase 4 of
the OP Public Participation Pilot Process developed by the Tolerance Reassessment Advisory
Committee, and initiated Phase 5 of that process. During Phase 5, all interested parties were
invited to participate and provide comments and suggestions on ways the Agency might mitigate
the estimated risks presented in the revised risk assessments. This public participation and
comment period commenced on August 16, 2000, and closed on October 16, 2000.

     Based on its review, EPA has identified risk mitigation measures that the Agency believes
are necessary to address the human health and environmental risks associated with the current
use of chlorpyrifos.  The EPA is now publishing its interim decision on the reregi strati on
eligibility of and risk management decision for the current uses  of chlorpyrifos  and its associated
human health and environmental risks.  The reregi strati on eligibility and tolerance reassessment
decisions for chlorpyrifos will be finalized once the cumulative  risks for all of the
organophosphate pesticides are considered. The enclosed "Interim Reregi strati on Eligibility
Decision for Chlorpyrifos," which was approved on September 28, 2001, contains the Agency's
decision on the individual chemical chlorpyrifos.

     A Notice of Availability for this Interim Reregi strati on Eligibility Decision (IRED) for
chlorpyrifos was being published in the Federal Register.  To obtain a copy of the interim RED
document, please contact the OPP Public Regulatory Docket (7502C), US EPA, Ariel Rios
Building, 1200 Pennsylvania Avenue NW, Washington, DC 20460, telephone (703) 305-5805.
Electronic copies of the interim RED and all supporting documents are available on the Internet.
See http:www.epa.gov/pesticides/op.

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     This IRED for chlorpyrifos has been revised based on comments received during the public
comment period following the announcement of the availability of the chlorpyrifos IRED in the
Federal Register (66 FR 57073).  This revised IRED incorporates many of the comments that
were received, other comments will be addressed under separate cover.

     The interim RED is based on the updated technical information found in the chlorpyrifos
public docket. The docket not only includes background information and comments on the
Agency's preliminary risk assessments, it also includes the Agency's revised risk assessments
for chlorpyrifos (revised as of June 8, 2000), and a document summarizing the Agency's
Response to Comments.  The Response to Comments document addresses corrections to the
preliminary risk assessments submitted by chemical registrants, as well as responds to comments
submitted by the general public and stakeholders during the comment period on the risk
assessment.  The docket will also include comments on the revised risk assessment, and any risk
mitigation proposals submitted during Phase 5. During Phase 5, EPA and the technical
registrants of chlorpyrifos entered into an agreement to implement interim risk mitigation.

     This document and the process used to develop it are the result of a pilot process to
facilitate greater public involvement and participation in the reregi strati on and/or tolerance
reassessment decisions for these pesticides.  As part of the Agency's effort to involve the public
in the implementation of the Food Quality Protection Act of 1996 (FQPA), the Agency is
undertaking a special effort  to maintain open public dockets on the organophosphate pesticides
and to engage the public in the reregistration and tolerance reassessment processes for these
chemicals.  This open process follows the guidance developed by the Tolerance Reassessment
Advisory Committee (TRAC), a large multi-stakeholder advisory body that advised the Agency
on implementing the new provisions of the FQPA. The reregi strati on and tolerance reassessment
reviews for the organophosphate pesticides  are following this new process.

     Please note that the chlorpyrifos risk assessments and the attached interim RED concern
only this particular organophosphate. This interim RED presents the Agency's conclusions on
the dietary risks posed by exposure to chlorpyrifos alone.  The Agency has also concluded its
assessment of the ecological and worker risks associated with the use of chlorpyrifos.  Because
the FQPA directs the Agency to consider available information  on the  basis of cumulative risk
from substances sharing a common mechanism of toxicity, such as the toxicity expressed by the
organophosphates through a common biochemical interaction with the cholinesterase enzyme,
the Agency will evaluate the cumulative risk posed by the entire organophosphate class of
chemicals after considering  the risks for the individual organophosphates. The Agency is
working towards completion of a methodology to assess cumulative risk and the individual risk
assessments for each organophosphate are likely to be necessary elements of any cumulative
assessment.  The Agency has decided to move forward with individual assessments and to
identify mitigation measures necessary to address those human health and environmental  risks
associated with the current uses of chlorpyrifos.  The Agency will issue the final tolerance
reassessment decision for chlorpyrifos and finalize decisions on reregi strati on eligibility once the
cumulative risks for all of the organophophates are considered.

     This document contains generic and product-specific Data Call-Ins (DCIs) that outline
further data requirements for this  chemical.  Note that a complete DCI, with all pertinent

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instructions, is being sent to registrants under separate cover. Additionally, for product-specific
DCIs, the first set of required responses is due 90 days from the receipt of the DCI letter. The
second set of required responses is due eight months from the date of the DCI.

     In this interim RED, the Agency has determined that, with the exception of open-pour dust
formulations for fire ant control, chlorpyrifos products will be eligible for reregi strati on provided
that all the conditions identified in this document are  satisfied, including implementation of the
risk mitigation measures outlined in Section IV of the document.  The Agency believes that
current uses of chlorpyrifos may pose unreasonable adverse effects to human health and the
environment, and that such effects can be mitigated with the risk mitigation measures identified
in this interim RED. Accordingly, the Agency recommends that registrants implement these risk
mitigation measures immediately.  Sections IV and V of this interim RED describe labeling
amendments for end-use products and data requirements necessary to implement these mitigation
measures. Instructions for registrants on submitting the revised labeling can be found in the set
of instructions for product-specific data that accompanies this interim RED.

     Should a registrant choose not to implement any of the risk mitigation measures outlined in
this document, the Agency will continue to  have concerns about the risks posed by chlorpyrifos.
Where the Agency has identified any unreasonable adverse effect to human health or the
environment, the Agency intends to initiate appropriate  regulatory action to address this concern.
At that time, any affected person(s) may challenge the Agency's action.

     If you have questions on this document, the label changes necessary for reregi strati on, or
the generic DCI, please contact the Chemical Review Manager, Tom Myers, at (703) 308-8589.
For questions about product reregi strati on and/or the Product DCI that accompanies this
document, please contact Venus Eagle at (703) 308-8045.

                         Sincerely,
                         Lois A. Rossi, Director
                         Special Review and Reregi strati on Division
Attachment

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Interim Reregistration Eligibility Decision
                   for
              Chlorpyrifos

             Case No. (0100)

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                             TABLE OF CONTENTS

Executive Summary	viii

I. Introduction	1

II. Chemical Overview                                                            3
      A. Regulatory History	3
      B. Chemical Identification                                                    6
      C. Use Profile                                                              7
      D. Estimated Usage of Pesticide	8

III. Summary  of Chlorpyrifos Risk Assessment                                      10
      A. Human Health Risk Assessment  	10
            1. Dietary Risk from Food                                            11
                   a. Toxicity	11
                   b. FQPA Safety Factor                                         12
                   c. Population Adjusted Dose (PAD)	13
                   d. Exposure Assumptions  	13
                   e. Food Risk Characterization  	14
            2. Dietary Risk from Drinking Water                                   16
                   a. Surface Water  	17
                   b. Ground Water                                              18
                   c. Drinking Water Levels of Comparison (DWLOCs)	19
            3. Occupational and Residential Risk                                   20
                   a. Toxicity	20
                   b. Occupational Exposure and Risk                              24
                         1) Occupational Handler Exposure  	24
                         2) Occupational Handler Risk                            25
                         3) Occupational Postapplication Exposure	35
                         4) Occupational Postapplication Risk                      35
                   c. Residential Exposure and Risk	37
                         1) Residential Handler Exposure                          37
                         2) Residential Postapplication Exposure	37
                         3) Residential Postapplication Risk                        37
                         4) Incidents	39
            4. Aggregate Risk	39
                   a. Acute Aggregate Risk  	39
                   b. Short-Term Aggregate Risk                                  40
                   c. Intermediate-Term Aggregate Risk	42
                   d. Chronic Aggregate Risk                                      42
      B. Environmental Risk Assessment	43
            1. Environmental Fate and Transport                                  43

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             2. Ecological Risks                                                   44
                   a. Exposure Assumptions 	45
                   b. Toxicity	46
                   c. Summary of Risks to Nontarget Organisms 	48
                         1) Risks to Terrestrial Mammals                         50
                         2) Risks to Terrestrial Birds and Reptiles	50
                         3) Risks to Bees and Beneficial Insects                    50
                         4) Risks to Fish and Amphibians 	50
                         5) Risks to Aquatic Invertebrates                         51
                         6) Risks to Freshwater Organisms in Field Monitoring Studies
                                 	51
                         7) Risks to Piscivorous Birds and Mammals from
                                Bioconcentration of Chlorpyrifos in the Food Chain
                                 	52
                         8) Risks to Nontarget Plants                              52
             3. Risk Characterization of TCP                                      52
             4. Risk Quotients for Major Use Sites  	52
                         a. Corn	52
                         b. Cover Crops	54
                         c. Peanuts 	56
                         d. Cotton	57
                         e. Citrus	58
                         f. Golf Course Turf                                     59
             5. Incidents  	60

IV. Interim Risk Management and Reregistration Decision  	61
      A. Determination of Interim Reregistration Eligibility                         61
      B. Regulatory Position	62
             1. FQPA Assessment                                                62
                   a. "Risk Cup" Determination                                   62
                   b. Tolerance Summary  	63
                   c. Codex Harmonization 	68
                   d. Endocrine  Disrupter Effects                                 70
                   e. Labels  	70
      C. Regulatory Rationale 	71
             1. Benefits 	71
             2. Human Health Risk Mitigation                                     73
                   a. Dietary Mitigation	73
                         1) Acute Dietary (Food)                                 73
                         2) Chronic Dietary (Food)                               73
                         3) Drinking Water                                      74
                   b. Occupational Risk Mitigation	74
                         1) Agricultural and Ornamental/Greenhouse Handler Risks
                                 	74

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                         2) Agricultural and Ornamental/Greenhouse Postapplication
                               Risks  	85
                         3) Non-Agricultural Occupational Handler Risks  	86
                         4) Non-Agricultural Occupational Postapplication Risks    86
                   c. Residential Risk Mitigation	87
                         1) Residential Handler Risk                             87
                         2) Residential Postapplication Risk	87
            3. Environmental Risk Mitigation                                     87
            4. Other Labeling                                                   91
                   a. Endangered Species Statement                               91
                   b. Spray Drift Management  	91

V. What Registrants Need to Do                                                  93
      A. Manufacturing Use Products	95
            1. Additional Generic Data Requirements                              95
            2. Labeling for Manufacturing Use Products 	96
      B. End-Use Products                                                      97
            1. Additional Product-Specific Data Requirements	97
            2. Labeling for End-Use Products                                     97
      C. Existing Stocks                                                         97
      D. Labeling Changes Summary Table                                        97

VI. Related Documents and How to Access Them                                  114

VII. Appendices	114
      Appendix A.  Table of Chlorpyrifos Use Patterns Eligible for Reregistration    115
      Appendix B.  Table of Generic Data Requirements and Studies Used to Make the
                   Reregistration Decision	147
      Appendix C.  Technical Support Documents                                161
      Appendix D.  Citations Considered to be Part of the Data Base Supporting the
                   Interim Reregistration Decision (Bibliography)                  163
      Appendix E.  Generic Data Call-in 	213
      Appendix F.  Product Specific Data Call-In                                 215
      Appendix G.  EPA's Batching of Chlorpyrifos Products for Meeting Acute Toxicity
                   Data Requirements for Reregistration  	217
      Appendix H.  List of Registrants Sent this Data Call-In                       229
      Appendix I.  List of Available Related Documents and Electronically Available
                   Forms  	231
                                        in

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CHLORPYRIFOS TEAM

Office of Pesticide Programs:

Health Effects Division
Deborah Smegal
David Soderberg
Steven Knizner
Timothy Leighton
Jerome Blondell
Virginia Dobozy

Environmental Fate and Effects Division
William Rabert
James Lin

Biological  and Economic Analysis Division
Timothy Kiely
David Brassard
Donald Atwood
Neil Anderson

Registration Division
Dennis McNeilly
Akiva Abramovitch

Special Review and Reregi strati on Division

Robbi Farrell
Mark Hartman
Tom Myers
                                         IV

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GLOSSARY OF TERMS AND ABBREVIATIONS

AE          Acid Equivalent
a.i.          Active Ingredient
AGDCI      Agricultural Data Call-In
ai            Active Ingredient
aPAD        Acute Population Adjusted Dose
AR          Anticipated Residue
ARC         Anticipated Residue Contribution
BCF         Bioconcentration Factor
CAS         Chemical Abstracts Service
CI           Cation
CNS         Central Nervous System
cPAD        Chronic Population Adjusted Dose
CSF         Confidential Statement of Formula
CFR         Code of Federal Regulations
CSFII        USDA Continuing Surveys for Food Intake by Individuals
DCI         Data Call-In
DEEM       Dietary Exposure Evaluation Model
DFR         Dislodgeable Foliar Residue
ORES        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, noncarcinogenic
             health effects are not anticipated to occur.
DWLOC     Drinking Water Level of Comparison.
EC          Emulsifiable Concentrate Formulation
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         Food and Agriculture Organization
FDA         Food and Drug Administration
FIFRA       Federal Insecticide, Fungicide, and Rodenticide Act
FFDCA      Federal Food, Drug, and Cosmetic Act
FQPA        Food Quality Protection Act
FOB         Functional  Observation Battery
G            Granular Formulation
GENEEC     Tier I Surface Water Computer Model
GLC         Gas Liquid Chromatography
GLN         Guideline Number
GM         Geometric Mean
GRAS        Generally Recognized as Safe as Designated by FDA

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HA          Health Advisory (HA). The HA values are used as informal guidance to
             municipalities and other organizations when emergency spills or contamination
             situations occur.
HAFT       Highest Average Field Trial
HOT         Highest Dose Tested
IR           Index Reservoir
LC50         Median Lethal Concentration. A statistically derived concentration of a substance
             that can be expected to cause death in 50% of test animals. It is usually expressed
             as the weight of substance per weight or volume of water, air or feed, e.g., mg/1,
             mg/kg or ppm.
LD50         Median Lethal Dose.  A statistically derived single dose that can be expected to
             cause death in 50% of the test animals when administered by the route indicated
             (oral, dermal, inhalation). It is expressed as a weight of substance per unit weight
             of animal, e.g., mg/kg.
LEL         Lowest Effect Level
LOG         Level of Concern
LOD         Limit of Detection
LOAEL      Lowest Observed Adverse Effect Level
MATC       Maximum Acceptable Toxicant Concentration
MCLG       Maximum Contaminant Level Goal (MCLG) The MCLG is used by the Agency
             to regulate contaminants in  drinking water under the Safe Drinking Water Act.
mg/kg/day    Milligram Per Kilogram Per Day
mg/L         Milligrams Per Liter
MOE        Margin of Exposure
MP          Manufacturing-Use Product
MPI         Maximum Permissible Intake
MRTD       Master Record Identification (number). EPA's system of recording and tracking
             studies submitted.
NA or N/A   Not Applicable
NAWQA     USGS National Water Quality Assessment
NOEC       No Observable Effect Concentration
NOEL       No Observed Effect Level
NOAEL      No Observed Adverse Effect Level
NPDES      National Pollutant Discharge Elimination System
OP          Organophosphate
OPP         EPA Office of Pesticide Programs
OPPTSEPA Office of Prevention, Pesticides and Toxic Substances
Pa           pascal, the pressure exerted by a force of one newton acting on an area of one
             square meter.
PAD         Population Adjusted Dose
PADI        Provisional Acceptable Daily Intake
PAG         Pesticide Assessment  Guideline
PAM         Pesticide Analytical Method
PCA         Percent Crop Area
                                         VI

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PDF         USDA Pesticide Data Program
PHED       Pesticide Handler's Exposure Data
PHI          Preharvest Interval
ppb          Parts Per Billion
PPE         Personal Protective Equipment
ppm         Parts Per Million
PRN         Pesticide Registration Notice
PRZM/
EXAMS      Tier II Surface Water Computer Model
Qj*          The Carcinogenic Potential of a Compound, Quantified by the EPA's Cancer Risk
             Model
RAC         Raw Agriculture Commodity
RBC         Red Blood Cell
RED         Reregi strati on Eligibility Decision
REI          Restricted Entry Interval
RfD         Reference Dose
RQ          Risk Quotient
RS          Registration Standard
RUP         Restricted Use Pesticide
SAP         Science Advisory Panel
SCI-GROW  Tier I Ground Water Computer Model
SF          Safety Factor
SLC         Single Layer Clothing
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.
TRR         Total Radioactive Residue
UF          Uncertainty Factor
Mg/g         Micrograms Per Gram
Mg/L         Micrograms Per Liter
USDA       United States Department of Agriculture
USGS       United States Geological Survey
WHO        World Health Organization
WP          Wettable Powder
WPS         Worker Protection Standard
                                         vn

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Executive Summary

       EPA has completed its review of public comments on the revised risk assessments and is
issuing its interim reregi strati on eligibility decision for chlorpyrifos.  The decisions outlined in
this document do not include the final tolerance reassessment decision for chlorpyrifos; however,
some tolerance actions will be undertaken prior to completion of the final tolerance
reassessment.  EPA intends to revoke the  tolerance for tomatoes, because that use is being
canceled, and to reduce the tolerances for grapes and apples.  The final tolerance reassessment
and reregi strati on eligibility decision for this chemical will be issued once the cumulative risks
for all of the organophosphates are considered. The Agency may need to pursue further risk
management measures for chlorpyrifos once cumulative risks are considered.

       The revised risk assessments are based on review of the required target data base
supporting the use patterns of currently registered products and new information received.  The
Agency invited stakeholders to provide proposals, ideas or suggestions on appropriate mitigation
measures before the Agency  issued its risk mitigation decision on chlorpyrifos.  After
considering the revised risks taking into account the interim mitigation as well as additional
mitigation proposed by Dow AgroSciences (DAS), one of the technical registrants of
chlorpyrifos, and comments and mitigation suggestions from  other interested parties, EPA
developed its risk management decision for  remaining uses of chlorpyrifos that pose risks of
concern. This decision is discussed fully  in  this document.

       Chlorpyrifos is an organophosphate insecticide, acaricide and miticide used to control a
variety of insects, first registered in 1965  for control of foliage and soil-borne insect pests on a
variety of food and feed crops. Technical registrants include Dow AgroSciences, Cheminova,
Inc., Gharda USA, Inc., Luxembourg-Pamol, Inc., Makhteshim-Agan of North America, Inc. and
Platte Chemical Company, Inc.  Chlorpyrifos is one of the most widely used organophosphate
insecticides in the U.S. and, until 2000 when nearly all residential uses were cancelled, was one
of the major insecticides used in residential  settings.  Currently registered uses include food and
feed crops, golf course turf, greenhouses,  non-structural wood treatments  such as utility poles
and fence posts, and as an adult mosquitocide.  Structural treatments for termites are also
currently registered, but are being phased out. All use of products for structural termite control
will be prohibited after December 31, 2005, unless acceptable data demonstrate that risks from
these exposures are not of concern. Indoor non-residential uses include shipholds, railroad
boxcars, industrial plants and manufacturing plants.

       Based on data reflecting usage for the years 1987 through 1998, the  Agency estimates
that the annual total domestic usage of chlorpyrifos was approximately 21 to 24 million pounds
active ingredient (ai) for 8 million acres treated in the U.S. Approximately  11 million pounds
were applied annually in non-agricultural settings (i.e., residences, schools,  golf courses, parks)
prior to the implementation of interim mitigation in 2000. The largest agricultural market for
chlorpyrifos in terms of total pounds ai is corn (-5.5 million).  The largest non-agricultural
markets in terms of total pounds ai applied were pest control operators (PCOs) for termite
control (5 million), and turf (2.5 million). Crops with a high average percentage of their total

                                           viii

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U.S. planted acres treated include Brussels sprouts (73%), cranberries (46%), apples (44%),
broccoli (41%) and cauliflower (31%).

       In June, 2000, the Agency released its revised human health risk assessment and entered
into an agreement with the technical registrants to eliminate and phase out certain uses of
chlorpyrifos.  The agreement was established at that time in order to expeditiously address food,
drinking water, residential and non-residential uses posing the greatest risks to children.  The
mitigation contained in the agreement also reduced some occupational and ecological exposures
by eliminating use sites and reducing application rates. Details of the interim risk mitigation can
be found on the internet at http://www.epa.gov/pesticides/op/.

       The technical registrants have since agreed to additional mitigation measures addressing
occupational and ecological risks not addressed in the June, 2000 agreement.  These measures
are the result of discussion between the Agency and the technical registrants during Phase 5 of
the public participation process, and are in the process of being implemented.

Overall Risk Summary

       EPA's preliminary human health risk assessment for chlorpyrifos indicated  dietary (food
and drinking water), occupational and residential risk concerns. The revised risk assessment
indicates that, with implementation of the June 2000 mitigation agreement, dietary  risks from
food are not of concern. Drinking water risk estimates based on screening models and
monitoring data from both ground and surface water for acute and chronic exposures are
generally not of concern.  The exception is incidents of contamination resulting from termiticide
use, which are highly localized and expected to be declining because the termiticide use is being
phased out. There are concerns for some workers who mix, load, and apply chlorpyrifos to
agricultural and other non-residential sites.

       Application of chlorpyrifos poses acute and reproductive risks to many non-target aquatic
and terrestrial animals for all outdoor uses reviewed.  The risk quotients for all chlorpyrifos uses
exceed the levels of concern for most terrestrial and aquatic categories.  In general,  risk quotients
are greater among estuarine species than freshwater species. Terrestrial animals are at less risk
than aquatic species. Birds appear to be more at risk than most mammalian species. Aquatic
risk quotients for ground spray applications are less than aerial spray applications at the same
application rate.

       Results of the risk assessments,  and the label amendments that EPA believes will
mitigate risks to  acceptable levels taking into account the benefits of chlorpyrifos use, are
presented in this interim RED.
                                            IX

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Dietary Risk

       The preliminary risk assessment showed that acute dietary risks from food exceeded the
acute population adjusted dose (aPAD) for infants, all children, and nursing females of child-
bearing age (13-50 years old).  To address these risks, the technical registrants agreed to
eliminate use on tomatoes and restrict use on apples. EPA will revoke the tomato tolerance and
lower the apple tolerance to ensure that both domestic and imported commodities do not contain
residues of concern. Use on apples is restricted to dormant (pre-bloom) applications; the
tolerance will be lowered to reflect this. In addition, the tolerance on grapes will be lowered to
reflect the currently registered use. The proposed tolerance actions be announced in the Federal
Register and will have a public comment period separate from the comment period for this
IRED. With this mitigation, acute risks from food are not a concern for any population
subgroup.

       Acute and chronic exposures to drinking water do not exceed the DWLOCs and are
therefore not of concern.  Drinking water risk estimates based on screening models and
monitoring data from both ground and surface water for acute and chronic exposures are
generally not of concern.  The exception is incidents of contamination resulting from termiticide
use, which are highly localized and expected to be declining with the  phasing out of the
termiticide use and implementation of generic risk mitigation for termiticides (reduction of the
concentration during the phase-out period.)

       Chronic dietary risk from food and drinking water does not exceed the Agency's level of
concern for the general U.S. population or for any population subgroup.

Occupational Risk

       Occupational exposure to chlorpyrifos is of concern to the Agency.  Exposures of
concern include mixing/loading liquids for aerial/chemigation and groundboom application,
mixing wettable powder for groundboom application, aerial application,  and application by
backpack sprayer, high-pressure handwand, bulbous duster and hand-held sprayer. Generally,
these risks can be mitigated by a combination of additional personal protective equipment and
engineering controls, and by reductions in application rates.  Additionally, the Agricultural
Handler Task Force will be developing exposure data to better characterize the risk from certain
uses (e.g., applying granulars by air).

       Postapplication risks can be mitigated by reducing application rates for a number of uses
and in some cases by the establishment of new restricted entry intervals,  i.e., the amount of time
that must elapse before risks are not of concern to workers re-entering treated fields.

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Residential Risk

       Risks to residents, particularly children, from chlorpyrifos use in the home, as well as
residential postapplication risks following residential treatments are a concern. To mitigate these
risks, the technical registrants agreed in June 2000 to cancel almost all indoor and outdoor
residential uses.  Virtually all products labeled for homeowner use have been canceled effective
December 31, 2001, except containerized ant and roach baits in child-resistant packaging which
have not been canceled because they present minimal exposure. Distribution and sale of
products for all other residential uses will be prohibited after December 31, 2001. The
application rate for termite treatments was reduced as of December 1, 2000. Full-barrier (whole-
house) termite treatment products may no longer be distributed or sold after December 31, 2001.
Spot and local post-construction use will be canceled on December 31, 2002, and pre-
construction termiticide uses will be canceled on December 31, 2005, unless acceptable exposure
data are submitted and demonstrate that postapplication risks to residents are not of concern.

Non-Agricultural Non-Residential Risk

       Risks to children in schools and parks, both indoors and outdoors, are of concern to the
Agency. Therefore, per the mitigation agreement signed in June 2000, distribution and sale of
products bearing these uses will be prohibited effective December 31, 2001. The only non-
agricultural non-residential uses that will be reregistered are golf course turf, shipholds, railroad
boxcars, industrial plants, manufacturing plants, and processed wood products, none of which
are expected to result in risks to children.  Exposure data are required to confirm that exposure to
residents from chlorpyrifos-treated wood products is not of concern.

Aggregate Risk

       Acute, short-term and chronic aggregate assessments were conducted. Taking into
account residential risk mitigation, aggregate risks are not a concern for any of these scenarios.

Ecological Risk

       Risk quotients indicate that a single application of chlorpyrifos poses risks to small
mammals, birds, fish and aquatic invertebrate species for nearly all registered outdoor uses.
Multiple applications increase the risks to wildlife and prolong exposures to toxic
concentrations. In most cases, acute risk quotients exceed 1 for the most sensitive, small
mammals and birds. All aquatic acute and reproductive risk quotients exceed 1; many aquatic
risk quotients exceed 10 and 100, and both acute and reproductive risk quotients  for estuarine
invertebrates exceed 1,000 on some crops.  In a few cases at maximum application rates,
chlorpyrifos may bioconcentrate in the tissues offish and aquatic invertebrates to levels that
exceed acute LC50 values for sensitive bird species and reproductive NOAELs for birds and
small mammalian species.  Hence without mitigation to reduce levels in shallow waters,
                                            XI

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bioconcentration of chlorpyrifos in ponds and estuarine areas may pose acute and/or
reproductive risks to aquatic birds and mammals feeding adjacent to treated areas.

       To address these risks, a number of measures including reduced application rates,
increased retreatment intervals, reduced seasonal maximum amounts applied per acre, and no-
spray setback zones around water bodies will be needed.

Interim Reregistration Eligibility Decision

       With the addition of the label restrictions and amendments detailed in this document, the
Agency has determined that all currently registered uses of chlorpyrifos, except open-pour dust
formulations, may continue until the cumulative risks for all of the organophosphates have been
considered.

       The Agency is issuing this interim Reregistration Eligibility Decision (RED) for
chlorpyrifos, as announced in a Notice of Availability published in the Federal Register.  This
interim RED document includes guidance and time frames for making label changes for products
containing chlorpyrifos. There will be a 60-day public comment period for this interim RED.
Phase 6 of the pilot process did not include a public comment period; however, for some
chemicals, the Agency may provide for another comment period, depending on the content of the
risk management decision.  Neither the tolerance reassessment nor the reregi strati on eligibility
decision for chlorpyrifos can be considered final, however, until the cumulative risks for all
organophosphate pesticides are considered.  The cumulative assessment may result in further
risk mitigation measures for chlorpyrifos.
                                           xn

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I.  Introduction

       The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) was amended in 1988
to accelerate the reregi strati on of products with active ingredients registered prior to November
1, 1984.  The amended Act calls for the development and submission of data to support the
reregi strati on of an active ingredient, as well as a review of all submitted data by the U.S.
Environmental Protection Agency (referred to as EPA or "the Agency").  Reregi strati on involves
a thorough review of the scientific database underlying a pesticide's registration. The purpose of
the Agency's review is to reassess the potential 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" criteria of
FIFRA.

       On August 3, 1996, the Food Quality Protection Act of 1996 (FQPA) was signed into
law.  This Act amends FIFRA to require tolerance reassessment of all existing tolerances. The
Agency had decided that, for those chemicals that have tolerances and are undergoing
reregi strati on, the tolerance reassessment will be initiated through this reregi strati on process. It
also requires that by 2006, EPA must review all tolerances in effect on the day before the date of
the enactment of the FQPA. FQPA also amends the FFDCA to require a safety finding in
tolerance reassessment based on factors including an assessment of cumulative effects  of
chemicals with a common mechanism of toxicity.  Chlorpyrifos belongs to a group of pesticides
called organophosphates, which  share a common mechanism of toxicity—they all affect the
nervous system by inhibiting cholinesterase. Although FQPA significantly affects the  Agency's
reregi strati on process, it does not amend any of the existing reregi strati on deadlines. Therefore,
the Agency is continuing its reregi strati on program while it resolves the remaining issues
associated with the implementation of  FQPA.

       This document presents the Agency's revised human health and ecological risk
assessments; its progress toward tolerance reassessment; and the interim decision on the
reregi strati on eligibility of chlorpyrifos. It is intended to be only the first phase in the
reregi strati on process for chlorpyrifos.  The Agency will eventually proceed with its assessment
of the cumulative risk of the OP  pesticides and issue a final reregi strati on eligibility decision for
chlorpyrifos.

       The implementation of FQPA has required the Agency to revisit some of its existing
policies relating to the determination and regulation of dietary risk, and has also raised a number
of new issues for which policies  need to be created.  These issues were refined and developed
through collaboration between the Agency and the Tolerance Reassessment Advisory Committee
(TRAC), which was composed of representatives from industry, environmental groups, and other
interested parties. The TRAC identified the following science policy issues it believed were key
to the implementation of FQPA and tolerance reassessment:

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       Applying the FQPA 10-Fold Safety Factor
       Whether and How to Use "Monte Carlo" Analyses in Dietary Exposure Assessments
       How to Interpret "No Detectable Residues" in Dietary Exposure Assessments
       Refining Dietary (Food) Exposure Estimates
       Refining Dietary (Drinking Water) Exposure Estimates
       Assessing Residential Exposure
       Aggregating Exposure from all Non-Occupational Sources
       How to Conduct a Cumulative Risk Assessment for Organophosphate or Other Pesticides
       with a Common Mechanism of Toxicity
•      Selection of Appropriate Toxicity Endpoints for Risk Assessments of Organophosphates
•      Whether and How to Use Data Derived from Human Studies

       The process developed by the TRAC calls for EPA to provide one or more documents for
public comment on each of the policy issues described above. Each of these issues is evolving
and in a different stage of refinement. Some issue papers have already been published for
comment in the Federal Register and others will be published shortly.

       In addition to the policy issues that resulted from the TRAC process, the Agency issued,
on September 29, 2000, a  Pesticide Registration Notice (PR 2000-9, Worker Risk Mitigation for
Organophosphate Pesticides, hereafter referred to as the Worker PR Notice) that presents EPA's
approach for managing  risks from Organophosphate pesticides to occupational users.  The
Worker PR Notice describes the Agency's baseline  approach to managing risks to handlers and
workers who may be exposed to Organophosphate pesticides, and the  Agency expects that other
types of chemicals will be handled similarly. Generally, basic protective measures such as
closed mixing and loading systems, enclosed cab equipment, or protective clothing, as well as
increased reentry intervals will be necessary for most uses where current risk assessments
indicate a risk and such protective measures are feasible.  The policy also states that the Agency
will assess each pesticide  individually, and based upon the risk assessment, determine the need
for specific measures tailored to the potential risks of the chemical. The measures included in
this interim RED are consistent with the Worker PR Notice.

       This document consists of six sections.  Section I contains the regulatory framework for
reregistration/tolerance  reassessment as well as descriptions of the process developed by TRAC
for public comment on science policy issues for the Organophosphate pesticides and the Worker
PR notice.  Section II provides a profile of the use and usage of the chemical. Section III gives
an overview of the revised human health and environmental effects risk assessments resulting
from public comments and other information.  Section IV presents the Agency's interim decision
on reregistrati on eligibility and risk management decisions. Section V summarizes the label
changes necessary to implement the risk mitigation  measures outlined in Section IV.  Section VI
provides information on how to access related documents. Finally, the Appendices include Data
Call-In (DCI) information. The revised risk assessments  and related addenda are not included in
this document, but are available on the Agency's web page www.epa.gov/pesticides/op, and in
the public docket.

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II.  Chemical Overview

       A. Regulatory History

       Chlorpyrifos, [0,0-diethyl 0-(3,5,6-trichloro-2-pyridinyl)-phosphorothioate], is a broad-
spectrum, chlorinated organophosphate insecticide, acaricide and nematicide that was first
registered in 1965 to control foliage- and soil-borne insect pests on a variety of food and feed
crops.  Chlorpyrifos' most common trade names are Dursban®, Empire 20®, Equity®, and
Whitmire PT 270®.  Lorsban® is a trade name for agricultural-use products. It is one of the
most widely used organophosphate insecticides in the U.S., and until recently was one of the
major insecticides used in residential settings. During the years 1987 to 1998, approximately 21
to 24 million pounds were used annually in the U.S., of which  approximately 11 million pounds
were applied in non-agricultural settings.  At one time there were over 400 registered  products
containing Chlorpyrifos on the market. Registered uses included: a variety of food crops (i.e.,
there are approximately  112 tolerances for food/feed commodities); golf course turf; non-
residential sites such as industrial plants and vehicles; non-structural wood treatments such as
utility poles, fence posts, and processed wood products; and public health uses (to control
mosquitoes and fire ants) and impregnated in ear tags for cattle.  Chlorpyrifos is also registered
for  structural pest control for termites; however, this use is being phased out and will be
prohibited effective December 31, 2005, unless acceptable data demonstrate that exposures from
this use are not of concern.

       In January, 1997, the technical registrants entered into an agreement with the Agency to
reduce indoor exposures to  Chlorpyrifos, especially to children and other sensitive groups.
Indoor broadcast treatments, indoor total release aerosols/foggers, direct application to pets via
shampoos, dips and sprays, and paint additives were eliminated.

       In June 2000, the technical registrants entered into an agreement with the Agency to
eliminate and phase out nearly all uses that result in residential exposures.  The only exceptions
are  containerized baits and public health uses such as mosquito and fire ant control, which do not
pose risks of concern and provide important public health benefits. The agreement phased in the
various restrictions and cancellations to address higher risk uses of Chlorpyrifos first.  Because
much of the risk reduction involves increasing margins of safety, the agreement focused first on
mitigation that achieved the greatest risk reduction for children.  Allowing uses with lower risks
to continue for a specific period of time will help ensure that appropriate alternatives are
available for a reasonable and orderly transition.  The provisions of the agreement are
summarized in Table 1 below. This document does not present the risks for those uses that will
be phased out and/or have been canceled.  Discussion of the risks associated with these uses can
be found in the Human Health Risk Assessment, June 8, 2000, which is located in the public
docket and on the internet at www.epa/gov/pesticides/op.

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              Table 1.  Provisions of the June 2000 Memorandum of Agreement
Food Uses
Crop
Apples
Tomatoes
All Agricultural
Uses
Mitigation Measures
Production of chlorpyrifos products labeled for
post-bloom application is prohibited (only
production for pre-bloom, dormant application is
allowed)
Post-bloom use is prohibited
Production of products for tomato use is
prohibited
Classify new end-use products for restricted use or
package in large containers
New end-use products must bear revised
Restricted Entry Intervals (REIs)
Effective Dates
August - September 2000
Stop use (use prohibited) as of 12-
31-00
August - September 2000
Stop use as of 12-31-00
As of 12-1-00
As of 12-1-00
                                                Home Uses
Home lawn and most other
outdoor uses
Classify new end-use products for restricted use or
package in large containers (except baits in child
resistant packaging)

Use will be canceled
As of 12-1-00
                                                                             Stop formulation 12-1-00
                                                                             Formulators stop sale 2-1-01
                                                                             Retailers stop sale 12-31-01
Crack and crevice and most
other indoor uses
Classify new end-use products for restricted use or
package in large containers

Use will be canceled
As of 12-1-00
                                                                             Stop formulation 12-1-00
                                                                             Formulators stop sale 2-1-01
                                                                             Retailers stop sale 12-31-01

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Home Uses
Termiticides

Q Full barrier (whole
house) post-construction use
Q Spot and local
post-construction use
Q Pre-construction use
Classify new products for restricted use or package in
large containers
Limit use to 0.5% solution
Use will be canceled
Use will be canceled
Use will be canceled unless acceptable exposure data
show that risks are not of concern
As of 12-1-00
In label directions as of
12-1-00
Stop formulation 12-1-00
Formulators stop sale 2-1-01
Retailers stop sale 12-31-01
Stop formulation 12-1-00 unless
label has stop use date of 12-31-
02
Stop production 12-31-04
Stop use 12-31-05
Non-Residential Uses
Indoor areas where children
could be exposed (such as
schools)
Outdoor areas where
children could be exposed
(such as parks)
Uses will be canceled
Uses will be canceled
Stop formulation 12-1-00
Formulators stop sale 2-1-01
Retailers stop sale 12-31-01
Stop formulation 12-1-00
Formulators stop sale 2-1-01
Retailers stop sale 12-31-01
Non- Agricultural Uses that Will Remain
Residential use of containerized baits
Indoor areas where children will not be
exposed, including only ship holds, railroad
boxcars, industrial plants, manufacturing
plants, or food processing plants
In child resistant packaging

(Use allowed to continue)
New end-use product labels must
reflect only these uses as of 12-
1-00

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                                Non-Agricultural Uses that Will Remain
Outdoor areas where children will not be
exposed, including only:

Q  Golf course turf
  Road medians
  Industrial plant sites
Q Non-structural wood treatments
including fenceposts, utility poles, railroad
ties, landscape timbers, logs, pallets,
wooden containers, poles, posts, and
processed wood products

Public health uses:

Q Fire ant mounds
(drench and granular treatment)

Q Mosquito control
Reduce application rate from
4 Ibs/acre to 1 Ib/acre

Reduce maximum application rate to 1 Ib
ai/acre

Reduce maximum application rate to 1 Ib
ai/acre

(Continue at current rate)
For professional use only


For professional use only
                                   New end-use product labels must
                                   reflect only these uses as of 12-
                                   1-00
      B. Chemical Identification
                                  Cl.


                                  Cl


       •   Common name:

       •   Chemical name:


       •   Chemical family:

       •   Case number:

       •   CAS registry number:

       •   OPP chemical code:
     N      O  /   OC7H,
                OC2H5
        Chlorpyrifos

        [0,0-diethyl 0-(3,5,6-trichloro-2-pyridinyl-
        phosphorothioate]

        Organophosphate

        0100

        2921-88-2

        059101
       •   Empirical formula:
        C9HnCl3NO3PS

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       •   Molecular weight:            350.6

       •   Trade and other names:       Dursban®, Lorsban®, Empire 20®, Equity®,
                                         Whitmire PT270®

       •   Basic manufacturer:          Dow AgroSciences

       Technical chlorpyrifos is a white crystalline solid with a melting point of 41.5-42.5°C.
Chlorpyrifos is stable in neutral and acidic aqueous solutions; however, stability decreases with
increasing pH. Chlorpyrifos is practically insoluble in water, but is soluble in most organic
solvents (i.e. acetone, xylene and methylene chloride). Chlorpyrifos is not particularly volatile
based on its low vapor pressure of 1.87xlO"5mm Hg at 20°C (Merck Index, 11th Edition). Its
maximum attainable vapor concentration is 25 ppb at 25°C.

       C. Use Profile

       The following information is based on the currently registered uses of chlorpyrifos.

       •      Type of Pesticide:   Insecticide, acaricide and nematicide

       •      Summary of Use Sites:

              Food/Feed:                 Registered for use on the following crops/sites:
                                         cranberries, strawberries, citrus, apples, figs, pears,
                                         nectarines, cherries, peaches, plums, grapes,
                                         almonds, pecans, walnuts,  nut trees, onions,
                                         peppers, kale, broccoli, Brussels sprouts, cabbage,
                                         cauliflower, collards, cucurbits, asparagus,
                                         roots/tubers, corn, lentils, beans, peas,  sorghum,
                                         tobacco, wheat, alfalfa, peanuts, soybeans,
                                         sunflower, cotton, sugar beets, mint, bananas,
                                         pasture

              Other agricultural sites:      Cattle ear tags, Christmas trees, woodland

              Residential:          Structural treament for termites, containerized baits

              Public Health:        Fire ant mounds, mosquito adulticides

              Other Nonfood:      Golf courses, shipholds, boxcars, industrial plants,
                                  processed wood products

       •      Target Pests:  A wide variety of insects and related organisms, and root-knot
                            nematodes

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              Formulation Types Registered: Formulated as a liquid emulsifiable
              concentrate, granular, wettable powder, dry flowable, pressurized liquid, dust,
              ready-to-use solution, microencapsulated material, pellets/tablets, soluble
              concentrate and impregnated materials (eartags).

              Method and Rates of Application:

              Equipment:   Applied by aerial, chemigation, groundboom, tractor-drawn
                           granular spreader, airblast sprayer, low and high pressure hand
                           wands, hydraulic hand-held sprayer, shaker can, belly grinder,
                           push-type spreader, large tank sprayer, compressed air sprayer,
                           hose-end sprayer, aerosol sprayer, hand, and eartags.

              Method:      Foliar, bark, seed and soil-incorporated band or broadcast
                           treatments

              Rates:        Maximum application rates range from 0.5 Ib/ai/A to 8 Ib/ai/A.
                           The maximum number of applications per year range from  1 to 3.
                           Up to 4 applications are permissible in some citrus growing areas
                           (grove floor treatment).

              Timing:      Dormant,  delayed dormant, preplant, at-planting, transplanting,
                           postplant, post-transplant, preemergence and posternergence.

              Use Classification:   Any emulsifiable concentrate (EC) end-use product
                                  formulated from chlorpyrifos must be labeled as  a
                                  restricted use product. All other end-use products (other
                                  than containerized baits in child-resistant packaging) must
                                  either be labeled as restricted use or packaged in containers
                                  no smaller than 15 gallons of a liquid formulation or 25
                                  pounds of a dry formulation.
       D. Estimated Usage of Pesticide

       This section summarizes the best estimates available for many of the pesticide uses of
chlorpyrifos, based on available pesticide usage information for 1987-1998. Approximately 21
million pounds a.i. of chlorpyrifos were used annually, according to Agency and registrant
estimates. As  a result of the June 7, 2000 MO A, which eliminated residential uses and phased
out the termite uses, approximately 10 million pounds of chlorpyrifos will be phased out of the
market place.  Table 2 provides usage estimates for selected use sites. A full list of all uses of
chlorpyrifos, with the corresponding use and usage data  for each site, has been completed and is
in the "Quantitative Use Analysis," March 30, 2000, which is available in the public docket and
on the internet. The data, reported on an aggregate and site (crop) basis, reflect annual

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fluctuations in use patterns as well as the variability in using data from various information
sources. These estimates do not reflect reductions in use from mitigation that has been
implemented as a result of the Memorandum of Agreement.

             Table 2. Chlorpyrifos Estimated Usage for Representative Sites
Crop
Cranberries
Oranges
Oranges, Fresh
Oranges, Processed
Apples
Pecans
Walnuts
Sweet Corn
Sweet Corn, Fresh
Sweet Corn, Processed
Corn
Broccoli
Brussels Sprouts
Cauliflower
Tobacco
Wheat, Winter
Alfalfa
Peanuts
Cotton
Sugar Beets
Nursery/Greenhouse
PCOs, Termite Control2
PCOs, Other (Roaches, Ants,
Fleas, etc.)2
Lbs. Active
Ingredient
Applied (Wt.
Avg.)1
26,000
460,000
350,000
110,000
550,000
240,000
197,000
120,000
74,000
46,000
5,527,000
73,000
9,000
27,000
146,000
170,000
480,000
316,000
670,000
169,000
277,000
5,003,000
1,946,000
Percent Crop
Treated
(Likely
Maximum)
60
19
54
10
53
36
39
13
22
9
8
51
91
36
14
1
3
15
6
10
-
-
-
Percent Crop
Treated (Wt.
Avg.)
47
14
41
7
44
20
30
11
18
7
7
41
73
31
11
1
3
10
5
8
-
-
-

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Crop
Mosquito Abatement Districts
Turf3'4
Households, Outdoor4
Lbs. Active
Ingredient
Applied (Wt.
Avg.)1
29,000
2,519,000
1,112,000
Percent Crop
Treated
(Likely
Maximum)
-
-
-
Percent Crop
Treated (Wt.
Avg.)
-
-
-
1 Weighted average is based on data for 1987-1998; the most recent years and more reliable data are weighted more
heavily.
2 Mitigation implemented in June 2000 included phase-out or cancellation of products for this use.
3 Includes golf courses, turf farms, institutional turf, lawncare control operators, and landscape contractors.
4  Products registered for residential use were cancelled effective December 31, 2000.
III.  Summary of Chlorpyrifos Risk Assessment

       Following is a summary of EPA's revised human health and ecological risk findings and
conclusions for the organophosphate pesticide chlorpyrifos, as fully presented in the documents,
Human Health Risk Assessment for Chlorpyrifos, June 8, 2000, and Fate and Environmental
Risk Assessment, dated June 2000, and addenda thereto.  The purpose of this summary is to assist
the reader by identifying the key features and findings of these risk assessments, and to better
understand the conclusions reached in the assessments.

       These risk assessments for chlorpyrifos were presented at a Technical Briefing on June 8,
2000, which was followed by an opportunity for public comment on risk management for this
pesticide. The risk assessments presented here form the basis of the Agency's risk management
decision for chlorpyrifos only; the Agency must consider cumulative risks of all the
organophosphate pesticides before any final decisions can be made.

       A. Human Health Risk Assessment

       EPA issued its preliminary risk assessments for chlorpyrifos in Phase 3 of the  public
participation process on October 18, 1999. In response to  comments and new studies  submitted
during Phase 3, and mitigation measures agreed to by the technical registrants to address risks
identified in the preliminary assessments, the risk assessments were updated and refined. The
major revision to the human health risk assessment was the reassessment of acute dietary risks to
reflect the cancellation of the tomato use and reduction of the grape and apple tolerances to 0.01
ppm; inclusion  of new data from the Agricultural Reentry  Task Force (ARTF); and preliminary
consideration of a new acute study with human subjects  and a new oral dog study with peripheral
nervous system measurements.  The registrant has submitted a rebuttal to the modification of the
tolerances. This rebuttal is under review.
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              1. Dietary Risk from Food

                     a. Toxicity

       The Agency has reviewed all toxicity studies submitted and has determined that the
toxicity database is complete, and that it supports an interim reregi strati on eligibility
determination. A brief overview of the studies used for the dietary risk assessment is outlined in
Table 3 in this document. Further details on the toxicity of chlorpyrifos can be found in the
Human Health Risk Assessment for Chlorpyrifos, June 8, 2000.

                   Table 3. Summary of Doses and Endpoints Selected
                        for Chlorpyrifos Dietary Risk Assessment
Exposure
Scenario
Acute
Dietary
Chronic
Dietary
NOAEL/Dose
(mg/kg/day)
NOAEL=0.5
LTF= 100
FQPA= 10
(infants, children and
females 13-50)
Endpoint
Significant (28-40%) plasma ChE
inhibition at peak time of (3-6 hours
post exposure) at 1 mg/kg/day
(Mendrala and Brzak 1998).
Significant 30% RBC ChE inhibition
4 hours post exposure at the LOAEL
of 1.5 mg/kg/day (Zheng et al. 2000).
Study
Acute Blood Time Course Study in
male rats (Mendrala and Brzak
1998) with support from Zheng et
al. (2000)
Acute RfD =0.005 mg/kg/day
Acute PAD (children and females 13-50) = 0.0005 or 5x10 4 mg/kg/day
Acute PAD (general population) = 0.005 or 5x10° mg/kg/day
NOAEL= 0.03
LTF=100
FQPA=10
(infants, children and
females 13-50)
Significant plasma and RBC
cholinesterase inhibition at the
LOAEL of 0.22 to 0.3 mg/kg/day
Weight of Evidence from 5 studies:
2 year dog
90 day dog
2 year rat
90 day rat
developmental neurotoxicity (DNT)
rat study (at 2 weeks)
Chronic RfD =0.0003 mg/kg/day
Chronic PAD (children and females 13-50) = 0.00003 or 3x10 5 mg/kg/day
Chronic PAD (general population) =0.0003 or 3x10 4 mg/kg/day
NOAEL = No Observed Adverse Effect Level
RBC = red blood cell
UF = Uncertainty Factor
PAD = Population Adjusted Dose (includes UF and FQPA safety factor)
       The Agency has evaluated the potential impact on the acute dietary risk assessment
following the submission of an acute (single oral dose) toxicity study with chlorpyrifos in
humans.  The following observations can be made on the potential impact of these data on the
chlorpyrifos risk assessment.  Because the study is a single oral dose, it could be used in a
weight-of-evidence approach to inform the selection of the inter-species uncertainty factor for
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acute dietary risk assessment. The Agency's evaluation did not include an independent review
of the ethical standards under which this study was conducted. The acute human study could be
compared to existing acute animal data to determine if the full ten-fold inter-species uncertainty
factor is needed to account for variation between species in the acute dietary assessment.
However, because of its limited duration, this study would not be adequate for use in short-term
or intermediate-term risk assessments, such as those used to estimate worker risk from
chlorpyrifos use, nor would it be appropriate for the chronic dietary assessment.

       The Agency has concluded that the primary metabolite of chlorpyrifos, 3,5,6-trichloro-2-
pyridinol (TCP), does not induce cholinesterase inhibition, and exhibits effects only at doses
high than those producing ChEI with chlorpyrifos, and therefore is less toxic than chlorpyrifos
(58 FR 19354, April 14, 1993). The primary toxicological effect after subchronic and chronic
exposure to TCP was alterations in liver enzymes seen at 30 mg/kg/day and increases in liver
and kidney weights  at 100 mg/kg/day.  Because of the potential exposure to TCP in food and
residential settings,  and evidence of increased susceptibility of rabbit fetuses relative to  dams, a
screening-level dietary risk assessment for TCP resulting from chlorpyrifos, chlorpyrifos-methyl
and trichlorpyr was  conducted. That assessment indicated that the percentage of the acute PAD
occupied for females 13+ years old (the population subgroup of concern for acute toxicity
effects) was 2.4%.  The percentage of the chronic PAD occupied ranged from 0.3% for the
general U.S. population to 0.7% for children  1-6 years old.  Upper-bound estimated
environmental concentrations of TCP exceeded chronic DWLOCs for children.  However, the
Agency believes that actual concentrations are probably considerably lower than modeled values
primarily because the acres treated with chlorpyrifos in any watershed is expected to be much
lower than 100% assumed in the modeling. Uncertainties with surface and groundwater
modeling are discussed more fully in the Summary of Risks to Nontarget Organisms later in this
document. More detailed information on TCP and the screening assessment can be found in the
"Preliminary Risk Assessment for Trichloropyridinol (TCP) Metabolite," June 5, 2000,  which is
available in the public docket and on the internet at www.epa.gov/pesticides/op.

                    b. FQPA Safety Factor

       The FQPA 10X Safety Factor has been retained due to increased susceptibility and
sensitivity to chlorpyrifos among neonates when compared with  adults, and for the  qualitative
increased susceptibility occurring at the high dose in the developmental neurotoxicity (DNT)
study (cholinesterase inhibition in dams versus structural effects on developing brain of the
offspring).  In  addition, recent data in the literature suggest that the inhibition of cholinesterase
may not be essential for adverse effects on brain development. Further uncertainty arises from
the lack of an offspring No Observed Adverse Effect Level (NOAEL) in the DNT.  In that study,
structural alterations in brain development were the toxicity endpoint of concern and were seen
at the lowest dose tested. The registrant has submitted a rebuttal to the EPA review of the DNT
study.  This rebuttal is under review.

       The FQPA Safety Factor is applicable to females 13-50 as well as infants and children,
for all exposure durations.  The FQPA Safety Factor is applicable to the following assessments:

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•   Acute Dietary Assessment - The FQPA safety factor is applicable to the Females 13-50 and
    Infants and Children population subgroups for the acute dietary assessment because adverse
    effects could result from a single exposure to chlorpyrifos (as demonstrated in several open
    literature studies including Zheng et al.).

    Chronic Dietary Assessment - The FQPA safety factor is applicable to the Females 13-50
    and Infants and Children population subgroups due to the concern that potential adverse
    effects could result from repeated exposure to chlorpyrifos (as demonstrated, for example, in
    the developmental neurotoxicity study in rats).

•   Residential and Other Non-Occupational Exposure Assessment - The FQPA safety factor is
    applicable for Females 13-50 and the Infants and Children population subgroups for all
    exposure durations due to the adverse effects resulting from single and repeated exposure(s)
    to this organophosphate insecticide in and around residential (non-occupational) settings.

                     c. Population Adjusted Dose (PAD)

       The Population Adjusted Dose, or PAD, is a term that characterizes the dietary risk of a
chemical, and reflects the Reference Dose (RfD), either acute or chronic, that has been adjusted
to account for the FQPA safety factor (i.e., RfD/FQPA safety factor). A risk estimate that is less
than 100% of the acute or chronic PAD does not exceed the Agency's risk concern.

                     d. Exposure Assumptions

       Chlorpyrifos is registered for use on  a wide variety of food crops, and has approximately
112 tolerances for food and/or feed commodities (which translates to approximately 700 food
forms in the dietary analysis). Food uses evaluated in this analysis were those reflected by the
established tolerances in/on raw agricultural, animal, and processed food/feed commodities for
chlorpyrifos as listed in 40 CFR §180.342.  Food handling establishment (FHE) tolerances were
also included as cited in 40 CFR §180.342(a)(4) for the chronic dietary analysis (i.e., as a result
of the registered use in FHE, all foods have an established tolerance of 0.1 ppm, unless they are
covered by higher tolerances). The established tolerances  in/on raw agricultural, animal, and
processed food/feed commodities are expressed either in terms of the combined residues of
chlorpyrifos and its metabolite TCP or as chlorpyrifos per se. The Agency has determined that
residues of TCP are not of concern for the chlorpyrifos dietary assessment, and concluded that it
can therefore be excluded from the tolerance expression. Proposed tolerances are supported by
available residue chemistry data and are expressed in terms of chlorpyrifos per se.  Thus, for
purposes of this analysis, only residues of chlorpyrifos per se were considered, when data were
available.  Whenever possible, data for anticipated residues (ARs) reflect levels of chlorpyrifos
per se.

       Highly refined acute and chronic  dietary risk analyses for chlorpyrifos were conducted
with the Dietary Exposure Evaluation Model (DEEM™).  DEEM incorporates consumption data
generated in USDA's Continuing Surveys of Food Intakes by Individuals (CSFII), 1989-91.  For

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chlorpyrifos, inputs to the DEEM analysis also include DAS's National Food Survey (NFS,
1993-1994), U.S. Department of Agriculture's Pesticide Data Program (PDF) monitoring data
(1994-1999), the Food and Drug Administration (FDA) Surveillance Monitoring Program data
(1992-1998), and field trial residue data.  Percent crop treated data were supplied by EPA's
Biological and Economic Analysis Division (see Quantitative Usage Analysis for Chlorpyrifos,
March 30, 2000, available in the public docket). Where percent crop treated estimates indicated
no chlorpyrifos use, a default assumption of 1% crop treated was applied.  In general, when
residues on commodities were nondetectable, one-half the limit of detection (LOD) was
assumed. All available processing and cooking factors were incorporated into the dietary
exposure analysis.

       For chronic dietary risk assessments, the three-day average of the consumption data for
each subpopulation is combined with average residues in commodities to determine the average
exposure in mg/kg/day. For acute dietary risk assessment, the entire distribution of single day
food consumption events is combined with a distribution of residues (probabilistic analysis,
referred to as "Monte Carlo") to obtain a distribution of exposures in mg/kg/day.
                    e. Food Risk Characterization

       Generally, a dietary risk estimate that is less than 100% of the acute or chronic PAD does
not exceed the Agency's risk concerns.  A summary of acute dietary risk estimates is shown in
Table 4.  Based on use patterns before the June 2000 mitigation agreement, the chlorpyrifos
acute dietary risk from food at the 99.9th percentile for the most highly exposed subpopulation,
children 1-6 years old, was 355% of the aPAD.

       Commodities that contribute the most to that risk estimate are apples (residues resulting
from post-bloom uses), grapes (residues primarily on imported crops) and fresh tomatoes
(residues primarily on imported crops).  Measures agreed to in the June 2000 agreement
addressed these risks by canceling use on tomatoes and revoking the associated tolerance;
restricting use on apples to pre-bloom (dormant) applications and reducing the tolerance to 0.01
ppm to reflect this new use pattern; and reducing the tolerance on grapes to 0.01 ppm to reflect
the domestic dormant use pattern. The registrant has submitted a rebuttal to the modification of
the tolerances. This rebuttal is under review.

       With these measures in place, at the 99.9th percentile, the dietary risk from food alone is
below 100% of the aPAD for all population subgroups, including the most sensitive population
subgroup, children 1-6 years old, with 82% of the aPAD occupied.  Thus acute dietary risks from
food alone are not of concern.
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 Table 4. Acute Dietary (Food Only) Risk Estimates for Chlorpyrifos as Percent of aPAD
Subpopulation
U.S. population
All infants
Children 1-6
Children 7-12
Females 13+ , nursing
Pre-Mitigation1
99.9th Percentile
16%
130%
355%
270%
130%
Post-Mitigation2
99.9th Percentile
4.1%
50%
82%
62%
39%
       'Pre-mitigation refers to uses/use patterns in effect prior to the June 2000 mitigation agreement.
       2Post-mitigation reflects changes in use/use patterns for tomatoes, apples and grapes as set forth in the June
       2000 mitigation agreement.

       The chronic dietary risk from food alone is not of concern, as shown in Table 5. Input
values included PDF, FDA and Dow AgroSciences' (DAS') 1993 National Food Survey (NFS) (a
market basket survey), average residues from field trials, and percent crop treated data compiled
by the Agency. Exposure estimates were below 100% of the cPAD for the most highly exposed
subgroup, children 1-6 years old.  With mitigation measures for apples, tomatoes and grapes in
place per the June 2000 agreement and assuming use in food handling  establishments, exposure
for children 1-6 years old, the highest exposure subgroup, occupies 51% of the cPAD, and thus
is not of concern.

 Table 5. Chronic Dietary (food only) Risk Estimates for Chlorpyrifos as Percent of cPAD
Subpopulation
U.S. population
All infants
Children 1-6
Children 7-12
Females 13+ , nursing
Pre-Mitigation1 99.9th Percentile
4%
45%
81%
59%
30%
Post-Mitigation2 99.9th Percentile
2.5%
33%
51%
36%
20%
       'Pre-mitigation refers to uses/use patterns in effect prior to the June 2000 mitigation agreement.
       2Post-mitigation reflects changes in use/use patterns for tomatoes, apples and grapes as set forth in the June
       2000 mitigation agreement.
       These assessments are the most refined estimates of risk from exposure to Chlorpyrifos
through food, although some uncertainties exist.  PDF data indicate that Chlorpyrifos residues
were detected in several commodities for which tolerances do not exist, specifically spinach,
carrots, squash, lettuce, potatoes and celery.  These residues were not included in the Agency's
risk estimates because they represent misuse of Chlorpyrifos. However, additional assessments
                                            15

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were conducted using spinach, carrots and squash, the commodities most frequently fed to
children. These assessments were not significantly different from the mitigated acute or chronic
dietary assessments and thus are not of concern.

       A tolerance also does not exist for chlorpyrifos in freshwater fish. In a screening level
assessment of the health risks to individuals who consume freshwater fish conducted by the EPA
Office of Water in 1992, residues of chlorpyrifos were detected in fish from 26% of 388 sample
collection sites. These data suggest that consumption of freshwater fish could contribute to the
dietary exposures and risks from chlorpyrifos for sports fishermen and subsistence populations.
Risk estimates could be of concern for an individual who consumed the maximum detected
residue level daily for 70 years at a rate of 170 g/day; however, the Agency considers this
unlikely. Subsistence populations are not expected to have exposures or risk that exceed the
Agency's level of concern following chronic ingestion offish fillets containing the mean
detected residue level. For a more detailed discussion of risks from freshwater fish consumption,
please refer to the Human Health Risk Assessment for Chlorpyrifos., June 8, 2000.

              2. Dietary Risk from Drinking Water

       Drinking water exposure to pesticides can occur through ground water and surface water
contamination. EPA considers both acute (one day) and chronic (lifetime) drinking water risks
and uses either modeling or actual monitoring data, if available, to estimate those risks. For
chlorpyrifos, ground and surface water monitoring data were used as well as  conservative Tier 1
and Tier 2 modeling.  Modeling is considered to be an unrefined assessment and can provide  a
high-end estimate of risk.

       The GENEEC and PRZM-EXAMS models were used to estimate surface water
concentrations, and SCI-GROW was used to estimate groundwater concentrations.  All of these
are considered to be screening models, with the PRZM-EXAMS model being somewhat more
refined than the other two.

       The available environmental fate data suggest that chlorpyrifos has a  low potential to
leach to groundwater in measurable quantities from most typical agricultural uses, except
following termiticide use. Chlorpyrifos is persistent in concentrated applications used in
termiticide treatments. The available data indicate that the primary metabolite of chlorpyrifos,
TCP is more mobile and significantly more persistent in many soils, especially under anaerobic
conditions.  A screening-level dietary risk assessment for TCP indicated that drinking water
exposure following termiticide use may pose risks of concern to children. Generic risk
mitigation action for termiticides has been implemented. The technical registrants agreed in
June 2000 to a suite of mitigation measures for the termiticide products that will reduce the
potential for exposure from this use.  By December 31, 2000, the application rate was reduced to
a 0.5% solution, and use was restricted to professional applicators.  After December 31, 2001,
whole house (post-construction) treatment will not be allowed. The preconstruction termiticide
use will be eliminated by December 31, 2005, unless the registrants submit acceptable exposure
data that demonstrate that risks are not of concern.

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                     a. Surface Water

       The Agency examined data of over 3000 samples from 20 of the U.S. Geological
Survey's National Water Quality Assessment (NAWQA) Program study units for flowing
surface water collected from rivers and streams. Chlorpyrifos was detected in 15% of 1530
agricultural streams, 26% of 604 urban stream samples in 1997 and in 65% of 57 urban stream
samples from Georgia, Alabama and Florida in 1994.  The maximum reported dissolved
chlorpyrifos concentration in surface water was 0.4 ppb, with the majority  of detections below
0.1 ppb.  Although the data represent a large part of the U.S., they may not represent the most
vulnerable watersheds where chlorpyrifos use is pervasive.  A limited number of watersheds in
the U.S. may have  chlorpyrifos concentrations greater than 0.4 ppb due to higher usage rates or
greater pesticide runoff. In particular,  acute exposure levels could be higher for streams draining
watersheds with more intense chlorpyrifos use or for lakes and reservoirs for which there are
little data.

       For comparison, the Agency developed screening-level model estimates of chlorpyrifos
concentrations in surface water such as lakes and reservoirs using Tier I GENEEC and Tier II
PRZM/EXAMS. Inputs to the models included high exposure agricultural scenarios for major
crops (alfalfa, corn, citrus, and tobacco) at the maximum application rates.  Estimated 90-day
average and peak concentrations of chlorpyrifos in surface water using the PRZM/EXAMS
screening model were 6.7 ppb and 40.6 ppb, respectively. The modeled estimates represent a
pond draining an adjacent  100% treated field.  These estimates should be highly conservative for
most surface waters and all drinking water because it is unlikely that 100% of a watershed
constituting a major drinking water source would be treated with chlorpyrifos in a given year.

       After comparison of the NAWQA monitoring data and modeled  estimates, an upper-
bound range of concentrations was selected from the NAWQA study to assess acute and chronic
risks associated with non-termiticide uses for surface water.  For the acute  assessment, a range of
0.026 to 0.4 ppb was used.  The 0.026  ppb represents the 95th percentile chlorpyrifos
concentration, while the 0.4 ppb concentration is the maximum detected concentration from
streams and rivers.  Estimated environmental concentrations (EECs) used in the assessments are
shown in Table 6.

                Table 6.  Surface and Groundwater EECs for Chlorpyrifos
Drinking Water Source
Groundwater
Surface water
Estimated Environmental Concentration (ppb)
Acute
Chronic
0.007 to 0.103 (a)
0.026 to 0.4 (b)
0.026 (c)
       (a)     Concentrations predicted by screening-level model SCI-GROW. The value is considered an
              upper bound concentration estimate.
       (b)     Based on the 95th percentile and maximum detected concentrations from surface water
              monitoring data.
       (c)     Based on the 95th percentile surface water concentration from monitoring data

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       To assess chronic risks, 0.026 ppb was used. As indicated above, 0.026 ppb represents
the 95th percentile concentration from the NAWQA study. Although PRZM/EXAMS predicted a
peak concentration of 40.6 ppb for lakes and reservoirs, this estimate was not used to assess
chronic risks for the following reasons:  1) multi-month or annual mean concentrations in a
reservoir are expected to be less than the maximum reported concentrations in the flowing water
feeding the reservoir, which in this case is 0.4 ppb; therefore 40.6 ppb is unlikely to occur; and
2) the monitoring data demonstrate that chronic concentrations of chlorpyrifos in surface water
are unlikely to exceed 0.1 ppb.

                    b. Ground Water

       The Agency examined data of over 3000 samples of filtered well monitoring samples
from the NAWQA database, and in the Agency's Pesticides in Ground Water Data Base
(PGWDB). The NAWQA data showed that chlorpyrifos was detected in groundwater in fewer
than 1% of the 3000 wells sampled, with the majority of concentrations reported at <0.01 ppb,
and occasional detections at a maximum level of 0.026 ppb. Although the available monitoring
data represent a large part of the U.S., it is not clear that they represent the most vulnerable
groundwater where chlorpyrifos is used most intensively.  The PGWDB reports a maximum
detected concentration of 0.65 ppb.

       Chlorpyrifos concentrations in groundwater were also estimated using the screening-level
model SCI-GROW for four crops (corn, cotton, alfalfa and citrus). SCI-GROW predicted
chlorpyrifos concentrations ranging from 0.007 ppb (typical application to alfalfa) to 0.103 ppb
(maximum multiple applications to sweet corn). An analysis of both monitoring and modeling
data suggest that chlorpyrifos concentrations in 99% of potable water in the U.S. are unlikely  to
exceed 0.1 ppb. Based on these data, EECs ranging from 0.007 to 0.103 ppb were used to
evaluate both acute and chronic exposures for groundwater. The NAWQA monitoring data
support that the SCI-GROW estimates are conservative.

       Chlorpyrifos use as a termiticide is significant, with a recent estimate of seven million
pounds ai applied annually, constituting about 30% of the total annual use.  Chlorpyrifos
groundwater exposure from termiticidal use occurs only in wells located within 100 feet of the
treatment area and when the well casing is cracked. The maximum reported dissolved
concentration following termiticide use is 2090 ppb. The current U.S. EPA Health Advisory for
a child is 30 ppb.  Therefore, acute concentrations are estimated at 30 to 2090 ppb.  Chronic
concentrations are presumably significantly lower but persistent at detectable levels for at least
six months. Chronic concentrations following this use are estimated at 8.3 to 578 ppb.  These
values were derived by adjusting the acute concentrations for partial environmental degradation.

       The Agency is concerned about exposure associated with termiticide use.  However,
because these exposures are isolated incidents and because termiticide use is being phased down
with immediate reduction in applied concentrations, these exposures were not included in the
dietary risk assessment.  The following points support this determination.  First, the technical


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registrants state that this exposure only occurs in homes where the well is near or in the
foundation and the well casing is cracked. The Agency has determined that because of changes
made to termiticide labels as a result of the Label Improvement Process for Termiticides (PR
Notice 96-7 for termiticides), potential exposure from incidents of this type has been reduced.
For example, reported incidents associated with termiticide use were 28.2 per 100,000 homes in
1997 (before PR 96-7), and were 8.3 per 100,000 homes in 1998 (after PR 96-7).

       Secondly, the technical registrants agreed in June 2000 to a suite of mitigation measures
for termiticide products that reduced the potential for exposures from this use. By December 31,
2000, the application rate was reduced to a 0.5% solution, and use was restricted to professional
applicators.  After December 31, 2001, whole house (post-construction) treatment will not be
allowed. By December 31, 2005, all residential termiticide use will be canceled.

                     c. Drinking Water Levels of Comparison (DWLOCs)

       To determine the maximum allowable contribution of water-containing pesticide residues
permitted in the diet, EPA first looks at how much of the overall allowable risk is contributed by
food (and if appropriate, residential uses), and then determines a "drinking water level of
comparison" (DWLOC) to determine whether modeled or monitored concentrations exceed this
level. The Agency uses the DWLOC to estimate risk associated with exposure to pesticides in
drinking water. The DWLOC is the maximum concentration in drinking water which, when
considered together with dietary exposure, does not exceed a level of concern.

       For acute risk, the potential drinking water exposure derived from either ground or
surface water is not of concern for any population subgroup.  Long-term exposure to
chlorpyrifos as a result of well contamination from termiticide use could result in exposures of
concern; however, these incidents are unlikely given ongoing mitigation.  In addition, the
technical registrants have agreed to reductions in use in the interim until all termiticide use is
canceled.  This is discussed in greater detail  above and in Section IV of this document.
       Table 7 presents the calculations for the acute and chronic drinking water assessment.
Details of this analysis are found in the Human Health Risk Assessment for Chlorpyrifos, June 8,
2000.
                                           19

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               Table 7. Drinking Water DWLOC and EEC Comparisons
                            (Excluding Well Contamination)
Population Subgroup
U.S. Population
All Infants (<1 year)
Children (1-6 years)
Females (13-50 years)
DWLOCS (ppb)
Acute
166
2.4
0.9
9
Chronic
10
0.2
0.15
0.72
Estimated Environmental Concentrations
(ppb)
Ground
Water
Acute and
Chronic
0.007-0.103
Surface Water
Acute
0.026-0.4
Chronic
0.026
             3. Occupational and Residential Risk

                    a. Toxicity

       All risk calculations in this assessment are based on the most current toxicity information
available for chlorpyrifos, including a 21-day dermal toxicity study.  The toxicological endpoints
and other factors used in the occupational and residential risk assessments for chlorpyrifos are
shown in Table 8.
                                          20

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Table 8. Toxicological Endpoints and Other Factors Used in the
Occupational and Residential Risk Assessment for Chlorpyrifos

Exposure
Scenario
Dermal

Short-Term
1-30 days


Dermal

Intermediate-
Term
(1-6 months)
Long-Term
(>6 months)
Inhalation
Short-Term
(1-30 days)

Intermediate-
Term
(1-6 months)
NOAEL
Dose
(mg/kg/day)
Dermal
NOAEL =5

Absorbed
Dermal NOAEL = 0.1 5
(for biomonitoring) (a)
Oral
NOAEL = 0.03
(3% dermal absorption)




Inhalation
NOAEL = 0.1








Endpoint
Plasma and RBC cholinesterase
inhibition of 45 and 16%, respectively at
LOAEL of 10 mg/kg/day after 4 days.
(Dermal absorption factor not necessary)


Plasma and RBC cholinesterase
inhibition at LOAEL of 0.22 to 0.3
mg/kg/day




Lack of effects in 2 rat inhalation studies
at the highest dose tested; 43% plasma
and 41% RBC cholinesterase inhibition
following oral doses of 0.3 mg/kg/day
for 2 weeks in the DNT study





Study
21 -day dermal rat study





Weight of Evidence from 5
studies: 2 year dog , 90 day
dog, 2 year rat, 90 day rat,
DNT study (at 2 weeks)



Two 90 day rat inhalation
studies (NOAEL) and DNT
(LOAEL )





Target MOE
for Occupa-
tional
100





100






100






Target MOE for
Residential/Homeowner
Exposures
1000 (infants, children and
females 13-50)

100 (all other
subpopulations)

1000 (infants, children and
females 13-50)

100 (all other
subpopulations)


1000 (infants, children and
females 13-50)

100 (all other
subpopulations)



                            21

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Exposure
Scenario
Inhalation
Long-Term
(>6 months)
NOAEL
Dose
(mg/kg/day)
Oral
NOAEL=
0.03
(assume inhalation
absorption is 100% of oral
absorption)
Endpoint
Significant plasma and RBC
cholinesterase inhibition at 0.22 to 0.3
mg/kg/day
Study
Weight of Evidence from 5
studies: 2 year dog, 90 day
dog, 2 year rat, 90 day rat,
DNT(at2weeks)
Target MOE
for Occupa-
tional
100
Target MOE for
Residential/Homeowner
Exposures
1000 (infants, children and
females 13-50)
100 (all other
subpopulations)
NOAEL = No Observed Adverse Effect Level
RBC = red blood cell
UF = Uncertainty Factor
PAD = Population Adjusted Dose (includes UF and FQPA safety factor)
(a) For comparison with absorbed biomonitoring data, use dermal NOAEL of 0.15 mg/kg/day * 0.03 dermal absorption factor
                                                                   22

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       The Agency has evaluated a 6-week dietary study in dogs designed to assess
cholinesterase inhibition (ChEI) in peripheral nervous system (PNS) tissues, such as the heart
and leg muscles, as well as measure cholinesterase activity in the blood and brain.  The study
was conducted by DAS in Michigan to address regulatory requirements in the United Kingdom.
This type of study is not required under current EPA guidelines, but the Agency has
recommended direct measurement of ChEI in the target peripheral nervous system tissues as a
potential alternative to measuring ChEI in the blood only.

       This study conducted with beagle dogs was designed to assess for inhibition of red blood
cell (RBC), peripheral tissue (brain, nodose ganglion, left atrium, diaphragm and quadriceps
muscle) and brain acetylcholinesterase (AChE).  A separate report presented a histopathological
evaluation of the adrenal gland.

       All dogs survived the six week study and there were no clinical signs or effects on body
weight or food consumption. There were also no histopathological alterations in the adrenal
gland noted in the special assessment of this organ.  The results of this study demonstrates that in
the dog, RBC AChE is more sensitive than brain or peripheral tissue AchE. Overall, the
peripheral tissue data were considered too variable and the cohort of dogs too small to make a
meaningful evaluation of potentially small changes in AChE activity in these structures. There
were, however,  sufficient data to imply that peripheral tissue was not demonstrated to be
inhibited by chlorpyrifos. No definite conclusions that chlorpyrifos inhibits peripheral tissue
AChE can be drawn from the data with the four peripheral tissue preparations. The peripheral
tissue aspects of the study cannot be upgraded due to the small number of animals assessed  and
the variability of the data.

       If another study was conducted that addressed the study deficiencies and limitations as
described in the data evaluation  record and found to be acceptable, the following observations
could be made on the potential impact of these data on the chlorpyrifos risk assessment.  Because
the study would be a repeat dose over a 6 week period, it could be used in a weight-of-evidence
approach to inform the selection of short and intermediate term endpoints for the chlorpyrifos
worker risk assessment.  Taking into account the established dermal absorption rate of rate of
3%, this study would yield MOEs 3-6 times greater than those currently shown in EPA's
assessment.  At a minimum, if the data are reliable, they could increase the confidence that
EPA's current assessment does not underestimate worker risk.

       The Agency uses the results of acute toxicity studies to determine early entry PPE and
other labeling requirements.  Acute toxicity values and categories for the technical grade of
chlorpyrifos are summarized in Table 9. Chlorpyrifos is moderately toxic following acute oral,
dermal and inhalation exposures, and is classified in toxicity category II for all three routes  of
exposure for rats.
                                           23

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       Table 9. Acute Toxicity Profile for Occupational Exposure for Chlorpyrifos
Study
Acute Oral LD% - rat
Acute Dermal LD50 - rat
Acute Dermal LDW - rabbit
Acute Inhalation LC50 - rat
Eye Irritation - rabbit
Dermal Irritation - rabbit
Dermal Sensitization - guinea pig
Acute Delayed Neurotoxicity -
hens
MRID Number
44209101
Accession No.
112115
44209102
00146507 and
Acc.No. 257590
44209103
44209104
44209105
00097144
00405106
Results
223 mg/kg M&F
202 mg/kg
>5000 mg/kg
LC50 > 0.2 mg/L (200 mg/m3)
(nominal concentration)
slight irritation resolved within 24
hours
mild irritant; (irritation resolved
within 7 days)
non-sensitizing
not neurotoxic at 50, 100 or 1 10
mg/kg
Toxicity
Category
II
II
IV
II
IV
IV
NA
NA
NA = Not Applicable
                    b. Occupational Exposure and Risk
                           1) Occupational Handler Exposure

       Several chemical-specific handler exposure studies conducted and submitted by the
technical registrants measured the exposures to professional pesticide applicators during
application of chlorpyrifos products. These data include biological monitoring of urinary TCP,
the primary metabolite of chlorpyrifos, and passive dosimetry data. In the absence of chemical-
specific data, the Pesticide Handlers Exposure Database (PHED) Version 1.1 was used to assess
potential exposures resulting from handling and applying chlorpyrifos. The  exposure factors
(e.g., body weight, amount treated per day, protection factors, etc.) are all standard values that
are used by the Agency, and the PHED unit exposure values are the best  available estimates of
exposure. Nevertheless, it should be noted that some aspects of the included studies (e.g.,
duration, acres treated, pounds of active ingredient handled) may not accurately represent labeled
uses in all cases. Further details on the data used for the assessments are discussed in the Human
Health Risk Assessment for Chlorpyrifos, June 8,  2000, which is available in the public docket
and on the internet at www.epa.gov/pesticides/op.

       Anticipated use patterns and application methods, range of application rates, and daily
amount treated were derived from current labeling and other available information. Application
rates specified on chlorpyrifos labels range from 0.25 to 8 pounds of active ingredient per acre.
                                           24

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The Agency typically uses acres treated per day values that are thought to represent a typical
work day for specific types of application equipment.

       Occupational handler exposure assessments are conducted by the Agency using different
levels of personal protective equipment (PPE). The Agency typically evaluates all exposures in
a step-wise fashion, first assuming minimal protection and then incrementally adding protective
measures until the target MOE is reached.  For agricultural handlers, the estimated exposures
considered PPE (a double layer of clothing and gloves and/or a dust/mist respirator), and
engineering controls (closed mixing/loading systems and enclosed cabs/trucks).

       The Agency identified 31 major occupational handler scenarios for which there were
potential exposures  during mixing, loading, and applying products containing chlorpyrifos to
agricultural crops and ornamentals (22 scenarios) and to non-agricultural use sites (9 scenarios)
such as sodfarms, golf courses and mosquito adulticide treatment. These scenarios reflect a
broad range of application equipment, application methods and use sites.  For agricultural uses,
handler activities include open and closed mixing/loading, and aerial, tractor-drawn and
handheld application. The application rates used in the assessment are intended to reflect the
upper range of rates on the labels. In some instances, the rates also include values that
registrants indicated were "typical" (e.g., a variety of sod farm rates, corn, citrus, greenhouse,
and nursery rates).

       The scenarios were classified as short-term (1  to 30 days) and intermediate-term (1 to 6
months). The handler scenarios for agricultural and golf course uses are expected to be of short-
term duration only; the scenarios for mosquitocide use are short- and intermediate-term; and the
scenario for pre-termiticide treatment is long-term (>6 months).
                           2) Occupational Handler Risk
       Agricultural and Ornamental/Greenhouse Handler Risk

       Combined dermal and inhalation margins of exposure for agricultural, ornamental and
greenhouse handlers range from 8 to 10,890. The following exposure scenarios (by number as
presented in Table 10) result in MOEs below 100 with engineering controls (or with PPE where
engineering controls are not feasible) and thus are of concern:

       (la)    Mixing/loading liquids for aerial/chemigation application at 1.5 Ibs. ai/A
       (Ib)    Mixing/loading liquids for groundboom application at 5 Ibs. ai/A
       (2a)    Mixing wettable powder for aerial/chemigation application at 2 and 3.5 Ibs. ai/A
       (2b)    Mixing wettable powder for groundboom application at 3 Ibs. ai/A
       (4a)    Aerial application of spray in enclosed cockpit at 2 Ibs. ai/A
       (4b)    Aerial application of granular in enclosed cockpit at 1.95 Ibs.  ai/A
       (12)    Application by backpack sprayer at 0.08 and 0.16 ai/gal, and at 3.5 Ibs. ai/A

                                           25

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       (14)   Application by high-pressure handwand at 0.0033 and 0.0066 Ibs. ai/gal
       (15)   Application by hydraulic hand-held sprayer for bark beetle treatment at 3.5 Ibs.
              ai/A and at 0.08 Ibs. ai/gal

       Seed treatment, pre-plant peach dip and dry bulk fertilizer impregnation were not
assessed due to a lack of appropriate data.
                                            26

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Table 10. Occupational Risk Estimates for Agricultural and Ornamental Uses of Chlorpyrifos
Exposure Scenario
(Scenario*)
Application Rates
(Ib ai/acre) (a)
Daily
Acres
Treated (b)
Short- Term PPE MOEs
Dermal
Inhalation
Total
Short- Term Eng. Control MOEs
Dermal
Inhalation
Total
Mixer/Loader Exposure
Mixing/Loading Liquids for
Aerial/Chemigation
Application (la)
Mixing/Loading Liquids for
Groundboom Application
(Ib)
Mixing/Loading Liquids for
Airblast Application (Ic)
Mixing WP for
Aerial/Chemigation
Application (2a)
Mixing WP for Groundboom
Application (2b)
1.5 cranberries, corn
3.5 citrus (c)
1.5 predominant
max
5.0 tobacco max (d)
2 Sodfarm
(includes
tobacco/potatoes)
4 Sodfarm (e)
8.0 sodfarm fire ants
2.0 predominant
max such as Fruits
&Nuts
6.0 citrus
2.0 predominant
max (orchards)
3.5 citrus (c)
1 .0 predominant
max (brassica)
4.0 soil treatment
ornamentals
outdoors
1.3 & 3.0 Sodfarm
8.0 sodfarm fire ants
(harvest only)
350
100
80
80
80
80
10
40
20
350
100
80
10
80
10
39
59
170
51
130
64
260
260
170
56
83
240
73
180
91
360
360
240
23
34
100
30
75
38
150
150
100
DAS is not supporting the open bag
formulation for the WP
78
120
160
240
52
78
Target MOE reached at PPE
100
250
130
210
530
260
69
170
86
Target MOE reached at PPE
Target MOE reached at PPE
Target MOE reached at PPE
51
100
450
890
340/150
4500
42
83
360
730
280 / 120
3600
23
46
200
400
150/67
200
                                         27

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Exposure Scenario
(Scenario#)
Mixing WP for Airblast
Application (2c)
Loading Granulars for Aerial
Application (3 a)
Loading Granulars for
Ground Application (3b)
Application Rates
(Ib ai/acre) (a)
2.0 predominant
max
6.0 citrus
1.95 maximum
aerial rate (f)
1.0 typical corn
2.0 max corn
3.0 maximum
ground rate
(tobacco)
Daily
Acres
Treated (b)
40
20
350
80
80
80
Short- Term PPE MOEs
Dermal
Inhalation
Total

150
1300
640
430
30
260
130
86
25
210
110
71
Short- Term Eng. Control MOEs
Dermal
450
300
3000
Inhalation
360
240
300
Total
200
130
270
Target MOE reached at PPE
Target MOE reached at PPE
8600
860
780
Applicator Exposure

Cockpit (4a)
Aerial (Granulars) — Enclosed
Cockpit (4b)
Groundboom Tractor (5)
Airblast Applicator (6)
Tractor-Drawn Granular
Spreader (7)
2.0 orchards
3.5 citrus (c)
1.95(f)
1.5 predominant
max
5.0 tobacco max (d)
4 Sodfarms (e)
8.0 sodfarm fire ants
2.0 predominant
max
6.0 citrus
1 .0 typical corn
2.0 max corn
350
100
350
80
80
80
10
40
20
80
80
No Open cockpit data available
No Open cockpit data available
The biological monitoring results (Table
A4) indicate that open cabs provide
insufficient protection . Therefore, only the
enclosed cab MOEs are presented.
The biological monitoring results indicate
that open cabs are insufficient.
1000
520
360
180
270
140
100
200
320
580
180
220
880
230
150
150
290
8
1400
410
510
2000
190
130
60
120
8
410
120
150
610
110
70
Target MOE reached at PPE
Tareet MOE reached at PPE
28

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Exposure Scenario
(Scenario#)

Seed Treatment (8)
Dip Application (Preplant
Peaches) (9)
Application Rates
(Ib ai/acre) (a)
3 .0 maximum
ground rate
(tobacco)
No Data
No Data
Daily
Acres
Treated (b)
80
No Data
No Data
Short- Term PPE MOEs
Dermal
350
Inhalation
120
Total
90
No Data
No Data
Short- Term Eng. Control MOEs
Dermal Inhalation
690 130
No Data
Total
110

No Data
Flagger Exposure
Spray Applications (10)
Granular Applications (11)
2.0 predominant
max
3.5 citrus (c)
1.95
350
100
350
50
100
320
140
290
340
37
74
170
2300 1400
4500 2900
880
1800
Target MOE reached at PPE
Mixer/Loader/Applicator Exposure
Backpack Sprayer (12)
Low Pressure Handwand (13)
0.0417 Ib ai/gal
predominant max /
0.08 Ib ai/gal bark
beetle treatment /
0.03 Ib ai/gal stump
treatment
3.5 citrus bark
0.039 Ib ai/gal /750
ft2
0.0417 Ib ai/gal
predominant max /
0.08 Ib ai/gal bark
beetle treatment /
0.03 Ib ai/gal stump
treatment
3.5 citrus bark
40 gal/day
1 A/day
1,000 ft2
40 gal/day
1 A/day
130 /
68 /
180
63
4200
570 /
300 /
790
270
700 / 360 /
970
330
22000
700 / 360 /
970
330
HO/58/
150
53
3500
310 / 160 /
440
150
Target MOE reached at PPE, except for the
higher concentration for the beetle bark treatment
Not feasible
Target MOE reached at PPE
Target MOE reached at PPE
Target MOE reached at PPE
29

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Exposure Scenario
(Scenario#)

High Pressure Handwand
(greenhouse uses) (14)
Hydraulic Hand-held Sprayer
for Bark Treatment (15)
Dry Bulk Fertilizer
Impregnation
Application Rates
(Ib ai/acre) (a)
0.039 Ib ai/gal/
750 ft2 animal
prem.
Min. 0.0033 Ib
ai/gal
Max. 0.0066 Ib
ai/gal
3.5 citrus bark
0.08 Ib ai/gal bark
beetle treatment
0.039 Ib ai/gal /750
ft2 animal prem
1.01bai/2001b
fertilizer / acre
Daily
Acres
Treated (b)
1,000 ft2
1,000
gal/day
10
1,000
gal/day
10,000 ft2
No Data
Short- Term PPE MOEs
Dermal
18,000
66
33
16
14/7
2,200
Inhalation
22,000
88
44
100
88/44
13,000
Total
10,000
38
19
14
12/6
1,900
No Data
Short- Term Eng. Control MOEs
Dermal Inhalation Total
Target MOE reached at PPE
Not feasible
Not feasible
Not feasible
Not Feasible
Target MOE reached at PPE
No Data
(a) Application rates are the maximum labeled rates found on EPA Reg. Nos. 62719-38, -221, -245, -34; -79, -72, -166, -220, 34704-66 (Clean Crop
Chlorpyrifos 4E ~ sodfarmfire ant rate), 499-367 (499-367 is the only greenhouse label identified), and 10350-22 for animal premise treatments.
"Predominant max" in this table refers to the most frequently identified maximum application rate found on the labels for the specific formulation
and equipment type.  Typical rates are also included to characterize the chlorpyrifos uses. Not all application rates are included for all crops, instead, a
cross-section of rates are used to represent the uses of chlorpyrifos.
(b) Daily acres treated are based on EPA's estimates of acreage (or gallonage) that would be reasonably expected to be treated in a single day for each
exposure scenario of concern. The sodfarm fire ant rate is restricted on the label for harvest only, therefore, this rate is limited to the amount of sod that
may be harvested in a reasonable time frame. Using the limited data available, 10 acres treated per day are assumed to be the upper range.
(c) The application rates on the Lorsban 4E (EPA Reg. No. 62719-220) and SOW (EPA Reg. No. 62719-39 discontinued as of 1995 and sold as -221)
labels indicate that for citrus at the 6.0 Ib ai/A rate it is necessary to use 100 to 2,400 gallons per acre dilute spray.  Therefore, this rate is not expected
to be feasible for an aerial applicator. The label language should be clarified so that the 6.0 Ib ai/A rate is for ground only.  Additionally, citrus
orchards are believed to be relatively small plots and 100 acres per day is assumed in the assessment for aerial applications.
(d) The 5.0 Ib ai/A rate for mixing/loading or applying liquids by groundboom application on tobacco has been canceled.
(e) The 4.0 Ib ai/A rate for mixing/loading or applying liquids by groundboom application to sodfarms has been reduced to 3.0 Ib ai/A.
(f) The 1.95 Ib ai/A rate for aerial mixing/loading or applying granulars has been reduced to a maximum of 1.0 Ib ai/A.
                                                                30

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       Non-Agricultural Occupational Handlers

       The following exposure scenarios (by number as presented in Table 11) result in
combined dermal and inhalation MOEs below 100 with label-recommended PPE, and thus are of
concern.

       (3)    Short-term groundboom applicators of liquids on golf courses at 1 Ib. ai/A
              wearing baseline PPE
       (5)    Short- and intermediate-term applicators of a dust product for control of fire ants
       (9)    Long-term mixer/loader/applicators of pre-construction termiticide treatments
              wearing baseline PPE
       (13)    Intermediate-term aerial applicators and mixer/loaders of mosquito adulticides
              using engineering controls at 0.023 Ibs. ai/A

       More detailed information on the non-agricultural occupational assessments can be found
in the Human Health Risk Assessment, June 8, 2000, in the public docket and on the internet at
www.epa.gov/pesticides/op.

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Table 11. Risk Estimates for Non-Agricultural Occupational Handlers
Application Scenario
Clothing
Method of
Evaluation
MOE
Dermal
Inhalation
Total
Risk Characterization/
Uncertainties
(3) Golf Course Use (Dursban Turf Insecticide; EPA Reg. 62719-35) (Short-term)
Mixer/Loader (Liquid)
Mixer/Loader (Wettable
Powder in water soluble bags)
Groundboom Applicator
Mix/Load/Apply via
Handgun (greens/tees)
(Liquid)
LS, LP, gloves
LS, LP, gloves
LS, LP, no gloves
LS, LP, gloves
PHEDV1.1
PHEDV1.1
PHEDV1.1
Biomonitoring
(MPJD 42974501)
PHEDV1.1
418
902
693
165
803
264
69
209
594
118
425
191
69
155
Central tendency estimate. Assumes
handling product to treat 40 acres at Ib
ai/acre. The Agency has more confidence
in the biomonitoring results than PHED.
Central tendency estimate. Assumes
handling product to treat 5 acres at 1 Ib
ai/acre.
(5) Insecticidal Dust Product (Shaker Can or Bulbous Duster)
Short-term
LS, LP, gloves
Scientific Literature
Study
108 (7.9 g)
4.3 (198 g)
NE
108 (7.9 g)
4.3 (198 g)
Central-tendency short term risk
assessments for 7.9 and 198 g ai;
High-end intermediate-term risk estimates
for 7.9 and 198 g ai (based on size of dust
container); inhalation exposure not assessed
due to an absence of data.
                               32

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Application Scenario
Intermediate-term
Clothing

Method of
Evaluation

MOE
Dermal
22 (7.9 g)
0.9 (198 g)
Inhalation
NE
Total
22 (7.9 g)
0.9 (198 g)
Risk Characterization/
Uncertainties

(9) Pre-Construction Termiticide Treatment (0.5% chlorpyrifos as Dursban TC) (EPA Reg. 62719-47) (long-term)
Mixer/Loader/
Applicator (3 hour average
exposure)
label-specified PPE:
single layer clothes
and forearm-length
chemically-resistant
gloves (forearm
length gloves not
required by label)
double layer clothes
(LS,LP, coveralls,
rubber boots, and
forearm-length
gloves) (forearm-
length gloves not
required by label)
Dosimetry and air
monitoring from
Registrant Study
MPJD No. 44589001
61
200
215
215
46
104
Low-end risk estimates for workers that
wore double layer of clothing and forearm
length gloves not required by the label;
Central-tendency risk estimates for workers
that wore a single layer of clothing and
forearm length gloves; assumes 3 hour
exposure, which could underestimate risks
to workers exposed > 3 hrs/day, or that use
2% ai to treat utility poles or fences
These MOEs have been adjusted to reflect
the dilution rate of 0.5% ai for all
termiticide products.
(13) Mosquitocide Mixer/Loader/Applicator (PHED VI. 1) (Short- and intermediate-term) (Mosquitomist One EPA Reg. 8329-24)
Mixer/Loader—Aerial
PPE double layer
clothes and gloves
Engineering
Controls (enclosed
cockpit)
single layer clothes
and gloves
PHED VI. 1
132 (ST)
26 (IT)
260 (ST)
52 (IT)
58 (ST&IT)
833(ST&IT)
40 (ST)
18 (IT)
198(ST)
49 (IT)
High end risk estimates. Application rate
of 0.023 Ib ai/acre for 7500 acres
33

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Application Scenario
Mixer/Loader—
Ground-based fogger
Aerial Applicator
Ground-based fogger
Applicator
Clothing
PPE, single layer
clothes and gloves
engineering
controls (enclosed
cab) and single
layer clothes and
gloves
engineering
controls (enclosed
cockpit) and single
layer clothes and no
gloves
engineering
controls (enclosed
cab) and single
layer clothes and no
gloves
Method of
Evaluation

MOE
Dermal
1111 (ST)
220 (IT)
297 (IT)
440 (ST)
89 (IT)
671-1353
(ST)
132-275
(IT)
Inhalation
663 (ST&IT)
4760 (IT)
2100
(ST&IT)
1820-3640
(ST)
1820-3640
(IT)
Total
415 (ST)
165 (IT)
280 (IT)
364 (ST)
85 (IT)
490-986
(ST)
123-256
(IT)
Risk Characterization/
Uncertainties
High end risk estimates. Application rates
of 0.005 and 0.01 Ib ai//acre for 3000 acres.
Surrogate ground-based fogger exposure
data are not available, and therefore, it was
necessary to extrapolate from airblast
exposure data
High end risk estimates. Application rate
of 0.023/acre for 7500 acres
High end risk estimates. Application rates
of 0.005 and 0.01 Ib ai/acre for 3000 acres.
Surrogate ground-based fogger exposure
data are not available, and therefore, it was
necessary to extrapolate from airblast
exposure data
LS=Long sleeves; LP = Long pants; SS = short sleeves; SP = short pants
H20 = water; ST = short-term (1- 30 days); IT = intermediate term (30 days to 6 months) LT = long term (> 6 months)
NE = Not evaluated
                                                                    34

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                           3) Occupational Postapplication Exposure

       Occupational postapplication exposure occurs when workers enter treated sites.  In the
agricultural setting, this includes scouts, pruners and harvesters, and may be of short- or
intermediate-term duration. In the recreational setting, this includes golf course maintenance
workers. Although a golf course maintenance worker may work up to 12 months per year,
chlorpyrifos levels on turf will decline fairly rapidly, and so exposures are expected to be of
short-term duration only. Postapplication activities are categorized as having low, medium and
high potential for dermal contact.

       Several chemical-specific postapplication exposure studies were conducted by the
technical registrants and submitted to the Agency. These studies included biological monitoring,
passive dosimetry and dislodgeable foliar residue (DFR) data.  Data were submitted for sugar
beets, cotton, sweet corn, almonds, pecans, apples, citrus, cauliflower, and tomatoes.

       Specific transfer coefficients were also monitored and submitted for citrus harvesting,
citrus tree pruning, cauliflower scouting, and tomato scouting.  Transfer coefficients for other
crops/activities have been submitted by the Agricultural Reentry Task Force (ARTF). In those
scenarios where data have not been submitted, the Agency's standard values for transfer
coefficients are used to estimate potential reentry exposure.

       Chemical-specific DFR data are not available for many crops that are treated with
chlorpyrifos.  Therefore, the assessment of exposures for those crops is based on typical
postapplication activities associated  with representative crops,  grouped according to their
potential for dermal contact. Table 12 summarizes the crops and activities in terms of potential
for dermal contact. Chemical-specific data are available for citrus, cauliflower, tree nuts and tree
fruits, and these crops are assessed separately.
                           4) Occupational Postapplication Risk

       For a detailed explanation of the preliminary occupational postapplication risk, refer to
the Agricultural and Occupational Exposure Assessment and Recommendations for the
Reregistration Eligibility Decision Document for Chlorpyrifos, dated June 19, 2000, which is
available in the public document.  In that preliminary risk assessment, restricted entry intervals
(REIs) were calculated using default assumptions for transfer coefficients (Tc). Since that time,
new exposure data for some activities have been submitted by the ARTF. The REIs have been
recalculated using the new data for particular activities and are shown below in Table 12.
                                           35

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         Table 12.  Restricted Entry Intervals Based on Data Submitted by ARTF
Crop
Citrus Trees
Fruit Trees
Cauliflower
Nut Trees
Potatoes
All Other Crops
Current REI
5 days
4 days
10 days
2 days
2 days
24 hours
Proposed
REI
5 days
4 days
3 days
24 hours
24 hours
24 hours
Activity
Pruning during wet conditions
Thinning
Using Tc for scouting,
weeding, irrigating or hoeing
New Tc for pruning or
thinning
New Tc for irrigation or
scouting
Scouting, harvesting
PHI
21 days
28 days
21 days
14 days
7 days
7 days
MOE
220
280
150
270
750
110
       Postapplication risks to golf course workers during mow/maintenance activities are
presented in Table 13. The short-term MOEs are above 100 (MOE 110 to 210) and therefore are
not of concern.  These risk estimates assume contact with golf course turf on the day of
treatment.

      Table 13. Short-term Postapplication Risks to Workers in Mow/Maintenance
                  Activities after Chlorpyrifos Treatment at 4 Ibs. ai/A
Transfer Coefficient
500 cm2/hour
1000 cm2/hour
DAT
0
0
Short-term MOE
210
110
       Postapplication risks to greenhouse/nursery workers were not assessed due to a lack of
data. Information is needed concerning the timing of the applications in relation to the
postapplication activities and a lack of residue data (foliar and bark treatments) to assess the
REIs for the ornamental/greenhouse uses.  These risks are of concern for activities such as
pruning, transplanting and burlap/balling.  The National Agricultural Pesticide Impact
Assessment Program (NAPIAP 1996) reports chlorpyrifos is widely used for a broad range of
insect applications including wood-boring, foliage feeding, sucking and soil-borne pests.
NAPIAP (1996) also reports that although chlorpyrifos use represents only 5% of the total Ibs. ai
used in greenhouse/nursery operations, it is used by 35% of the survey respondents. It is obvious
that chlorpyrifos is an important chemical for the industry, especially as a tool for resistance
management. With such reliance by an industry, it is important to collect additional use
information, greenhouse DFR data, and biological monitoring data to develop transfer
coefficients for various greenhouse/nursery activities.
                                          36

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                    c. Residential Exposure and Risk

                           1) Residential Handler Exposure and Risk

       Containerized baits in child-resistant packaging is the only residential use which may be
applied by the homeowner.  This use is not expected to result in exposures of concern.  For
further details, refer to the Human Health Risk Assessment for Chlorpyrifos, June 8, 2000, which
is available in the public docket and on the internet at www.epa.gov/pesticides/op.

                           2) Residential Postapplication Exposure

       Residential postapplication exposure occurs when people enter a treated golf course or
following an application for mosquito control by a public agency. Residential postapplication
exposures are expected to be of short-term duration (one day to one month).

       Environmental concentrations of chlorpyrifos in homes may also result from spray drift,
track-in, or from redistribution of residues brought home on the  clothing of farm workers or
pesticide applicators. The Agency is currently developing standard methodologies and guidance
to evaluate these exposures.  Modifications to EPA's assessment will be incorporated as that
guidance becomes available.

                           3) Residential Postapplication Risk

       No residential postapplication exposures pose risks of concern.  A summary of the risk
estimates, method of evaluation, and risk characterization/uncertainties is  presented in Table 14.
For residential postapplication risk, the target MOE is 1000. For golfers on a course treated at a
rate of 1 Ib. ai/A, MOEs arel500-2400.  Following aerial and ground-based fogger mosquito
adulticide use, MOEs are 17,000 and 29,000 for children and adults, respectively.
                                           37

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Table 14.  Postapplication Risk Estimates to Residents/Recreational Users
Reentry Scenario
Method of Evaluation
Central-tendency MOE
Adult
Child
Risk Characterization/
Uncertainties
(8) Golf Course Treatment (Dursban Turf Insecticide; EPA Reg 62719-35) (1 Ib ai/acre) (Short-term)
Adolescent Golfer (12 yrs;
44kg)
Adult Golfer
Residential SOPs and
surrogate residue data
from flurprimidol study
the day of treatment
1500 (lib ai/acre)
2400 (1 Ib ai/acre)
High-end risk estimates. Assumes exclusively dermal exposure
the day of turf treatment Assumes a 4 hour exposure for an 18-
hole round of golf.
(9) Aerial and Ground-Based Fogger Mosquitocide Application (Mosquitomist One, EPA Reg. 8329-24) (0.01 Ib ai/acre) (Short-term)
Dermal
Oral (hand to mouth)
Oral (Turfgrass Ingestion)
Oral (Soil Ingestion)
Total Exposure
Literature studies, the
AgDrift Model and the
updated Residential
SOPs
42,000
NE
NE
NE
42,000
26,000
13,000
54,000
20,000,000
15,000
High-end risk estimates based on the updated Residential SOPs.
Assumes long-term inhalation exposure is negligible based on low
application rate and infinite dilution.
                                 38

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                           4) Incidents

       Prior to implementation of the mitigation established in June 2000, chlorpyrifos was one
of the most widely used insecticides in the home both by consumers and PCOs or exterminators.
In a 1990 EPA-sponsored survey of pesticide use in households, chlorpyrifos was the fourth
most commonly used insecticide, present in 18% of all households. A 1993 EPA survey of
PCOs found it was the number one  insecticide in use and accounted for a quarter of the
poundage used in residential settings.  Consequently, there have been many reports of human
exposure and poisonings due to the widespread use of chlorpyrifos. The Agency estimates that
approximately 98% of chlorpyrifos exposures discussed in the incident reports were associated
with products removed as a result of the mitigation contained in the June 8, 2000 agreement.
Human and pet poisoning incidents associated with chlorpyrifos exposure are discussed in
greater detail in the Human Health Risk Assessment for Chlorpyrifos., June 8, 2000, which is
available in the public docket and on the internet at www.epa.gov/pesticides/op.

              4. Aggregate Risk

       An aggregate risk assessment combines risk from dietary exposure (food and drinking
water routes) and residential exposure (homeowner handler and postapplication exposures,
including incidental oral exposure for toddlers who put grass in their mouths following mosquito
adulticide use and exposure to treated golf course turf). As noted previously, this aggregate
assessment reflects the mitigation that reduced potential chlorpyrifos exposures from food
(elimination of use on tomatoes and limitations on the apple and grape uses) and  in the
residential/recreational  environment. Acute, short-term and chronic aggregate assessments were
conducted.  For this assessment, the target MOE is 1000. Results of the aggregate risk
assessment are summarized in here, and are discussed extensively in the Human Health Risk
Assessment for Chlorpyrifos., June 8, 2000.

                    a. Acute Aggregate Risk

       The acute aggregate risk assessment for chlorpyrifos addresses exposure from food and
drinking water. For the highly refined acute probabilistic dietary exposure analysis, PDF, FDA
and NFS monitoring data were used to the greatest extent possible, along with field trial data,
and cooking and processing factors to assess dietary exposures.  This aggregate assessment
incorporates the mitigation measures agreed to in June 2000 (i.e., reduction of apple tolerance  to
0.01 ppm to reflect dormant application, reduction of grape tolerance to 0.01 ppm based on
domestic use pattern, cancellation of use on tomatoes and revocation of the tolerance on
tomatoes).

       With the apple, grape and tomato mitigation measures in place, the acute dietary risk
estimates range from 4.1% to 82% of the aPAD, with children 1-6 years old being the most
highly exposed population subgroup.  Thus, the mitigated acute dietary (food only) risk estimate
for  chlorpyrifos exposure is not of concern. Acute estimated concentrations of chlorpyrifos in
groundwater, derived from a conservative screening-level model, range from 0.007 to 0.103 ppb.

                                           39

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The acute surface water EECs, taken from monitoring data, range from 0.026 to 0.4 ppb.  As
indicated in Table 15 below, the EECs are below the DWLOCs for all populations. Thus acute
food and drinking water exposures (except possible well contamination) are not of concern. It
should be noted that neither the SCI-GROW model nor the monitoring data reflect
concentrations after dilution (from source to treatment to tap) or drinking water treatment.

                    Table 15. Acute Aggregate Risk from Chlorpyrifos
                                 Including Risk Mitigation00
Population
Subgroup (b)
U.S. Population
All Infants (< 1
Year)
Children (1-6
years)
Females
(13-50 years)
Acute PAD
(ug/kg/day)
5
0.5
0.5
0.5
Food Exposure
99.9th
(ug/kg/day) (c)
0.237
0.258
0.410
0.201
Max. Water
Exposure
Cug/kg/day) (d)
4.76
0.242
0.09
0.299
Surface
Water EEC
(Ppb)
0.026-0.4
Ground
Water EEC
(Ppb)
0.007-0.103
Acute
DWLOC
(ppb) (e,f, g)
166
2.4
0.9
9
(c)
(a) Reflects mitigation implemented in June 2000 eliminating use on tomatoes and limiting use on grapes and apples.
(b) In addition to the U.S. population (all seasons), the most highly exposed subgroup within each of the infants,
   children, female groups is listed.
   99.9th percentile exposure.  Values are from Table 3 in Human Health Risk Assessment for Chlorpyrifos, June
   8, 2000 (and rounded).
   Maximum Water Exposure  (^g/kg/day) = Acute PAD (^g/kg/day) - [Acute Food Exposure (^g/kg/day)].
   DWLOC Cug/L) = Maximum water exposure (^g/kg/day) x body wt (kg) + water consumed daily (L/day)]
   Default body weights are: general U.S. population, 70 kg; adult females, 60 kg; and infants/children, 10 kg.
   Default daily drinking water rates are 2 L/day for adults and 1 L/day for children.
(d)
(e)
(f)
(g)
                     b. Short-Term Aggregate Risk
       The short-term aggregate risk estimate includes chronic dietary (food and water)
exposure and short-term non-occupational (i.e., residential/recreational uses) exposures from
Chlorpyrifos use. As noted previously, this aggregate assessment reflects the mitigation that
reduced potential Chlorpyrifos exposures from food (apples, grapes and tomatoes) and in the
residential/ recreational environment. This assessment evaluates potential exposures to treated
golf courses and as a result of mosquitocide treatment by public agencies.

       Table 16 presents the aggregate exposure estimates for chlorpyrifos from dietary and
residential/non-occupational uses (golfing and mosquito abatement).  Children 1-6 years old
were assumed to be exposed to residues on turf following ground-based fogger applications of a
mosquitocide and food residues.  Children 7-12 years were assumed to be dermally exposed to
chlorpyrifos residues while playing golf on the day of treatment, and to ingest food residues.
Female residents were assumed to be concurrently exposed to turf following mosquito
abatement, golfing  (dermal contact with turf on the day of treatment), and food residues.
                                             40

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       As shown in Table 16, aggregate MOEs are greater than 1000 for all subpopulations and
are not of concern.  Therefore, short-term DWLOCs were estimated to account for potential
drinking water exposures.

                       Table 16. Short-Term Aggregate Exposure
          [Chronic Dietary (Excluding Water) and Short-Term Residential Use]
                              Including Risk Mitigation(a)
Population
Subgroup
Children
(1-6 years)
Children
(7-12 years)
Females
13-50
Chronic
Dietary
Exposure
Food
(yug/kg BW/day)
(b) / MOE
0.008
MOE = 62,500
0.015
MOE = 33,000
0.006
MOE = 83,000
Short-Term Residential/Recreational Exposure
(/^g/kg/day)/ MOE Including Risk Mitigation
Mosquitocide Exposure
Oral
G/g/kg BW/day)
/MOE
0.013
MOE= 38,500
NE
NE
Dermal
G/g/kg BW/day)
/MOE
0.19
MOE = 26,000
NE
0.14 (d)
MOE= 36,000
Golf Course
Exposure
Dermal
Owg/kg BW/day)
/MOE
NE
3.4
MOE= 1,500
2.45 (d)
MOE = 2,000
Total Aggregate
MOE (c)
Dietary &
Residential
Exposure
Oral and Dermal
MOE
12,000
1,400
1,900
(a) Reflects mitigation implemented in June 2000 eliminating use on tomatoes and limiting use on grapes and apples.
(b) MOE calculated based on acute oral NOAEL of 500 ^g/kg/day, and short-term dermal NOAEL of 5000 ^g/kg/day .
(c) Oral and dermal exposures were combined because the oral and dermal endpoints are both based on plasma and RBC ChE
inhibition.
(d) Adjusted from 70 kg to 60 kg for aggregate exposure.
NE = Not evaluated.
       The short-term DWLOC values are presented in Table 17.  The EECs for chronic
exposures are below the DWLOCs for all populations.  Thus, potential short-term aggregate
exposure to chlorpyrifos resulting from food, water, golf course and mosquito abatement
exposures are not of concern. This analysis is conservative because the Agency assumed that
there could be concurrent residential and recreational exposures to chlorpyrifos (i.e., golfing and
mosquito abatement on the same day).  In addition, neither SCI-GROW nor the monitoring data
reflect concentrations after dilution (from source to treatment to tap) or drinking water treatment.
                                          41

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                   Table 17. Short-term Aggregate Exposure DWLOCs
                    (Chronic Dietary and Short-Term Residential Use)
                               Including Risk Mitigation(a)
Population
Subgroup (b)
Children (1-6
years)
Children
(7-12 years)
Females
(13-50 years)
Acute Oral
NOAEL
(ug/kg/day)
500
ST Food and
Residential
MOE (b)
12,000
1,400
1,900
Water
MOE
(c)
1,090
3,450
2,100
Max. Water
Exposure
O^g/kg/ day)
(d)
0.4587
0.14
0.238
Surface
Water
(Ppb)
0.026
Ground
Water
(Ppb)
0.007-0.103
ST
DWLOC
(ppb) (e,f,g)
4.5
1.4
7.1
(a) Reflects mitigation implemented in June 2000 eliminating use on tomatoes and limiting use on grapes and apples.
(b) Values are from Table 16.
(c) MOE,
[(1/MOEAGG - [1/MOEF
1/MOED
+ 1/MOEORAL ]), where MOEAGG is 1000.
(d) Maximum Water Exposure (^g/kg/day) = Acute NOAEL of 500 (^g/kg/day)^- MOEWATER
(e) DWLOC (ppb) = Maximum water exposure (/-ig/kg/day) x body wt (kg) + water consumed daily (L/day)]
(f) EPA default body weights are: adult females, 60 kg; and infants/children, 10 kg.
(g) EPA default daily drinking water rates are 2 L/day for adults and 1 L/day for children.
ST = short-term

                     c. Intermediate-Term Aggregate Risk

       No residential/recreational uses result in exclusively intermediate-term exposures (i.e.,
greater than 30 days but less than 6 months). Therefore, an intermediate-term aggregate risk
assessment was not conducted.

                     d. Chronic Aggregate Risk

       The chronic aggregate risk assessment for chlorpyrifos addresses exposures from food
and drinking water. For the highly refined chronic dietary exposure analysis, PDF, FDA and
NFS monitoring data were used to the greatest extent possible, along with field trial data, and
cooking and processing factors. This aggregate assessment incorporates the mitigation agreed to
in June 2000 (limitation of use the use on apples and grapes and deletion of use on tomatoes),
and assumes there are no chronic exposures from termiticide treatments, since these uses are
being phased down.

       The chlorpyrifos chronic dietary (food only) risk estimates range from 2.5 to 51% of the
cPAD, with children 1-6 years old being the most highly exposed population subgroup.  Thus,
the chronic dietary (food) risk from chlorpyrifos exposure is not of concern.

       Chronic groundwater EECs, derived from SCI-GROW, range from 0.007 to 0.103 ppb.
Chronic surface water EECs,  based on monitoring data, are estimated at 0.026 ppb.  The chronic
                                            42

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DWLOC values are shown below in Table 18. For all subpopulations, surface and groundwater
EECs are below the DWLOCs and therefore are not of concern.  These estimates are
conservative because neither the SCIGROW model nor the monitoring data reflect actual
drinking water concentrations after dilution (from source to tap) or drinking water treatment.

                     Table 18. Chronic Aggregate Exposure DWLOCs
                                  Including Mitigation (a)
Population
Subgroup (b)
U.S. Population
All Infants
(< 1 Year)
Children (1-6
years)
Females
(13-50 years)
Chronic
PAD
Oug/kg/day)
0.3
0.03
0.03
0.03
Chronic
Food Exposure
(jUg/kg/dayXc)
0.008
0.01
0.015
0.006
Max. Water
Exposure
(Mg/kg/day) (d)
0.292
0.02
0.015
0.024
Surface
Water
(Ppb)
0.026
Ground
Water
(Ppb)
0.007 to
0.103
Chronic
DWLOC
(ppb) (e,f,g)
10
0.2
0.15
0.72
(a)  Reflects mitigation implemented in June 2000 eliminating use on tomatoes and limiting use on grapes and apples.
(b)  In addition to the U.S. population (all seasons), the most highly exposed subgroup within each of the infants,
    children, female groups is listed.
(c)  Values are from Table 4 from the Human Health Risk Assessment, June 8, 2000 (and rounded).
(d)  Maximum Water Exposure (^g/kg/day) = Chronic PAD (^g/kg/day) - [Chronic Food Exposure + Chronic
    Residential Exposure (^g/kg/day) (if applicable)]. Chronic residential uses were not considered based on
    mitigation options.
(e)  DWLOC (ppb) = Maximum water exposure (,wg/kg/day) x body wt (kg) + water consumed daily(L/day)]
(f)  HED default body weights are: general U.S. population, 70 kg; adult females, 60 kg; and infants/children, 10
    kg.
(g)  HED default daily drinking water rates are 2 L/day for adults and 1 L/day  for children.

       B. Environmental Risk Assessment

       A summary of the Agency's environmental risk assessment is presented below. For
detailed discussions of all aspects of the environmental risk assessment, see the Fate and
Environmental Risk Assessment, dated October 1999 and revised March and June 2000, available
in the public docket and on the internet at www.epa.gov/pesticides/op.

              1. Environmental Fate and Transport

       The environmental fate database for chlorpyrifos is largely complete.  The major route of
dissipation appears to be aerobic and anaerobic metabolism. Abiotic hydrolysis,
photodegradation and volatilization do not seem to play significant roles in the dissipation
process. Based on available data, chlorpyrifos appears to degrade slowly in soil under both
aerobic and anaerobic conditions. Information on leaching and adsorption/desorption indicate
that parent chlorpyrifos is largely immobile. The environmental fate of the major chlorpyrifos
degradate, TCP, indicates that it is mobile in soils and persistent in soils when not exposed to
                                             43

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light. Available field data indicate that chlorpyrifos has a half-life in the field of less than 60
days, with little or no leaching observed. Because of its low water solubility and high soil
binding capacity, there is potential for chlorpyrifos sorbed to soil to run off into surface water via
erosion.  Chlorpyrifos has been detected in fish tissues.  Chlorpyrifos residues in aquatic species
may result in dietary exposure for aquatic birds and mammals feeding on aquatic organisms.
Chlorpyrifos rapidly depurates from fish when aquatic chlorpyrifos  exposures cease.

       The degradate TCP appears to be more persistent than chlorpyrifos (substantial amounts
remain 365 days after application) and it exhibits much lower soil/water partitioning than
chlorpyrifos. Consequently, substantial amounts of TCP are probably available for runoff for
longer periods than chlorpyrifos.  The relatively low soil/water partitioning of TCP indicates that
its concentrations in sediment and water are probably comparable, and that runoff occurs
primarily by dissolution in runoff water rather than by adsorption to eroding  soil.  The low
soil/water partitioning of TCP suggests that its bioaccumulation potential is probably low.

       Chlorpyrifos can contaminate surface water via spray drift at the time of application or as
runoff up to several months after application.  Available data indicate that most chlorpyrifos
runoff is generally via adsorption to eroding soil rather than by dissolution in runoff water.
However, under some conditions, dissolution in runoff water may be significant.

              2. Ecological Risks

       Risk characterization integrates the results of the exposure and ecotoxicity data to
evaluate the likelihood of adverse ecological effects.  The means of integrating the results of
exposure and ecotoxicity data is called the quotient method. For this method, risk quotients
(RQs) are calculated by dividing exposure estimates by ecotoxicity values, both acute and
chronic.

                                 RQ = Exposure/Toxicity

       RQs are then compared to EPA's levels of concern (LOCs).  The LOCs are criteria used
by OPP to indicate potential risk to nontarget organisms.  The criteria indicate that a pesticide
used as directed has the potential to cause adverse effects on nontarget organisms.

       Ecotoxicity endpoints derived from the results of short-term laboratory studies that assess
acute effects are: (1) LC50 (fish and birds) (2) LD50 (birds and mammals) (3) EC50 (aquatic plants
and aquatic invertebrates) and (4) EC25 (terrestrial plants).  Endpoints derived from the results of
long-term laboratory studies that assess chronic effects are NOAEL and LOAEL for birds and
mammals and NOAEC and LOAEC for fish and aquatic invertebrates.
                                            44

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       Risk presumptions along with the corresponding RQs and LOCs are shown below in
Table 19.

                 Table 19. Risk Presumptions for Non-target Organisms
Terrestrial Animals
Risk Presumption
Acute High Risk
Acute Restricted Use
Acute Endangered Species
Chronic Risk
RQ
EEC/LC™ or LD^/sqft2 or LD™/dav3
EEC/LC50 or LD50/sqft2 or LD50/day
(orLD™<50ms/ks)
EEC/LC™ or LD™/sqft2 or LD™/dav
EEC/NOAEL
LOC
0.5
0.2
0.1
1
Aquatic Animals
Acute High Risk
Acute Restricted Use
Acute Endangered Species
Chronic Risk
EEC/LC™ or EC™
EEC/LC™ or EC™
EEC/LC™ or EC™
EEC/NOAEC
0.5
0.1
0.05
1
Terrestrial and Semi-Aquatic Plants
Acute High Risk
Acute Endangered Species
EEC/EC,,
EEC/EC™ or NO AEC
1
1
Aquatic Plants
Acute High Risk
Acute Endangered Species
EEC/EC™
EEC/EC™ or NO AEC
1
1
       Calculated risk quotients represent a screening level assessment. Risk characterization
provides further information on the likelihood of adverse effects occurring by considering the
fate of the chemical in the environment, geographic patterns of chemical usage, communities and
species potentially  at risk, their spatial and temporal distributions and the nature of the effects
observed in the studies.

                    a. Exposure Assumptions

       Three types of terrestrial wildlife risk assessments were conducted.  For non-granular
pesticides, acute and  chronic dietary exposures were assessed by comparing estimated
environmental concentrations on food items to LC50 values. To assess risks from granular
products, acute exposures are expressed as LD50 per square foot. Acute risk quotients for
                                           45

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granular formulations were calculated by dividing the maximum milligrams of chlorpyrifos
exposed on the soil surface per square foot by LD50 values of various wildlife species times the
animal's body weight.

       For non-granular (liquid and dust) pesticides, the estimated environmental concentrations
(EECs) were compared with LC50 values to assess risk.  Maximum EECs were used to derive a
conservative estimate of risk to wildlife that may feed on foods with higher than average
residues. This risk assessment estimated risks to birds and mammals feeding on short grass or
foliage and fruits, seeds, and large and small insects, which provides a range of risk quotients
depending on the particular dietary needs of a wildlife species.  The assessment assumes that
animals would consume only chlorpyrifos- treated food items. Measured residue levels reported
in three field studies on corn, citrus and golf courses sprayed with chlorpyrifos support the use of
maximum residue levels for risk assessment. In case of soil incorporation following spray
applications, it is assumed that soil incorporation reduces the amount of treated vegetation and
seeds available to wildlife on the surface, but soil incorporation does not reduce the pesticide
concentration on these food items. Soil incorporation reduces the amount of pesticide available
for runoff.

       Estimated environmental concentrations in aquatic systems were modeled using
GENEEC and PRZM-EXAMS to reflect use on corn, citrus, peanuts, cotton and tobacco.  Use
patterns for these sites reflect the range of application rates, frequency of application, maximum
seasonal limits and application methods for chlorpyrifos.  Estimated concentrations derived from
the models were used to assess acute and chronic risks to freshwater and estuarine organisms in
ponds and estuarine areas, respectively. Concentrations reported in NAWQA and California
monitoring data were used to assess risks for some typical flowing waters. Acute risks were
assessed using peak EECs. Chronic risk quotients were calculated using an exposure period
ranging from 96 hours to 21 days.  For greater detail on exposure assumptions, see the Fate and
Environmental Risk Assessment., revised June 2000.

              b. Toxicity

       Extensive acute and chronic toxicity data are available for chlorpyrifos. A summary of
toxicity values used in terrestrial risk assessments is shown below in Table 20.
                                           46

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                Table 20. Summary of Terrestrial Toxicity Values Used In
                            Risk Assessment for Chlorpyrifos
Toxicity
Category
Mammalian
Acute LD50
Mammalian
Dietary LC™
Mammalian
Reproduction
NOAEL
Avian Acute
LDm
Avian Dietary
LC
-------
Toxicity Category

Estuarine
Invertebrate
Estuarine Algae

Reproductive NOAEC
Acute LC50
Reproductive NOAEC
Acute LC50
Toxicity Value
50 ppb (stonefly P. californica)
0.04 ppb (Daphnia magna)
0.035 ppb (Mysid shrimp)
2000 ppb (Oyster embryo-larvae)
O.0046 ppb (Mysid shrimp)
140-300 ppb (S. costatum)
              c. Summary of Risks to Nontarget Organisms

       The Agency calculated risk quotients for most agricultural and some non-crop uses such
as golf courses and perimeter treatments for termites. Risk quotients have been estimated based
on maximum use rates and maximum seasonal poundage permitted by the label for both acute
and chronic exposures.  In addition, typical use rates were assessed for selected major crops.
The chronic exposure values for assessing risks to avian and mammalian reproduction have been
modified since completion of the Fate and Environmental Risk Assessment, June 2000,  to reflect
mean residue levels on grasses, foliage, seeds and insects. Risk quotients for major use sites are
presented in this document. For detailed discussion of these and risk quotients for other uses, see
the Fate and Environmental Risk Assessment, June 2000, which is available in the public docket
and on the internet at www.epa/gov/pesticides/op.

       Risk quotients indicate that a single application of chlorpyrifos may pose high risks to
small mammals, birds, fish and aquatic invertebrate species  for nearly all registered outdoor
uses. For multiple applications, EPA assumes that residues  are additive and has used minimum
retreatment intervals along with calculated half-lives, half-lives for soils, foliage and water.
Multiple applications increase the risks to  wildlife and prolong exposures to toxic
concentrations. In most cases, acute risk quotients exceed 1 for the most sensitive small
mammals and birds. All aquatic acute and reproductive risk quotients exceed 1; many aquatic
risk quotients exceed 10 and 100; several risk quotients for estuarine invertebrates exceed 1,000.
In a few cases  at maximum application rates, chlorpyrifos may bioconcentrate in the tissues of
fish and aquatic invertebrates to levels that exceed acute LC50 values for sensitive bird species
and reproductive NOAELs for birds and small mammalian species.  Hence bioconcentration of
chlorpyrifos in ponds and estuarine areas may pose acute and/or reproductive risks to aquatic
birds and mammals feeding adjacent to treated areas.

       For aquatic risk assessments, the Agency used the screening-level model GENEEC to
predict concentrations of chlorpyrifos in water following a single application. To estimate
concentrations on a single site over multiple years, PRZM-EXAMS was used.  Peak EECs range
from 1  to 37 ppb. These EECs may be considered highly conservative because 1) the EECs
generated by both models reflect agricultural uses with the highest application rates of
chlorpyrifos, and 2) the EECs  represent one in ten-year concentrations in a one-hectare, 2-meter
                                           48

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deep farm pond or other water body with no outlet draining 10 hectares, 100% of which is
treated with chlorpyrifos. The aquatic risk quotients derived from these EECs are therefore
conservative. In addition, the RQs for estuarine organisms are likely to be even more
conservative than those for freshwater organisms. Concentrations in estuarine environments
could be expected to be much lower than in a contained pond because of flushing and dispersion
as a result of tidal fluctuations.  RQs derived from GENEEC may also overestimate aquatic risks
for crops with ground cover such as pome fruits and tree nuts.

       Endangered  species LOCs are exceeded for small mammals, birds, freshwater fish and
invertebrates, and estuarine fish and invertebrates for most chlorpyrifos uses.  The Fish and
Wildlife Service has reviewed the use of 4 EC, 15 G,  50 W and Dursban 10 CR on numerous
crops and as a mosquito larvicide. In several opinions, the most recent in 1993, FWS found
jeopardy for a few bird and amphibian species, a snake, and many species offish and aquatic
invertebrates, under the conditions of use at the time of the opinion.

       The Agency has consulted several times with the Fish and Wildlife Service (FWS) on the
potential effects of chlorpyrifos for various uses on endangered and threatened species. To date,
the FWS has issued  five Biological Opinions. In these Opinions, the FWS found jeopardy  for 35
fish species, 33 aquatic invertebrate species, 7 avian species, 4 amphibian species and  13 insect
species.  An additional  18 fish species, 2 aquatic invertebrate species, 1 avian species and 1
amphibian species were expected to be affected, but not jeopardized.  These consultations and
the findings expressed in the Opinions, however, are based on old labels and application
methods, less refined risk assessment procedures, and an older approach to consultation which is
currently being revised through interagency  collaboration.

       EPA's current assessment of ecological risks uses both more refined methods to define
ecological risks of pesticides and new data, such as that for spray drift. Therefore, the
Reasonable and Prudent Measures (RPMs) in the Biological Opinion(s) may need to be
reassessed and modified based on these new approaches.

       The Agency is currently engaged in a Proactive Conservation Review with FWS and the
National Marine Fisheries Service under section 7(a)(l) of the Endangered Species Act.  The
objective of this review is to clarify and develop consistent processes for endangered species risk
assessments and consultations.  Subsequent to the completion of this process, the Agency will
reassess the potential effects of the remaining chlorpyrifos uses to federally listed threatened and
endangered species. At that time, the Agency will also consider any regulatory changes
recommended in this IRED that are being implemented.  Until such time as this analysis is
completed, the overall environmental effects mitigation strategy articulated in this document and
the County Specific Pamphlets described below, will  serve as interim protection measures to
reduce the likelihood that endangered and threatened  species may be exposed to chlorpyrifos at
levels of concern.
                                           49

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                     1) Risks to Terrestrial Mammals

       Risk quotients for both maximum and typical use rates exceed the levels of concern for
small mammalian herbivores and insectivores for most crop and non-crop uses of chlorpyrifos.
The high risk LOG (0.5) for the mammalian acute oral LD50 values is usually exceeded for 15
gram mammals, frequently exceeded for 35 gram mammals and occasionally exceeded for 1000
gram mammals. The high risk LOG (0.5) for mammalian subacute dietary LC50 is rarely
exceeded, but the restricted use LOG (0.2) is exceeded frequently.  The LOG for reproductive
effects (1.0) is usually exceeded.

                     2) Risks to Terrestrial Birds and Reptiles

       Risk quotients for both maximum and typical application rates for spray uses usually
exceed the levels of concern for high risks (0.5) for subacute LC50s and (1.0) for reproduction
NOAEL for avian species.  Risk quotients  for both maximum and typical application rates for
granulars usually exceed the LOG for high acute risk. Several incidents with robins and other
bird species reported for lawn and residential perimeter treatments for termites support these  risk
quotients for birds and reptiles.

       Sensitivity of reptiles to pesticides is  assumed to be similar or less than for birds, hence
the avian risk quotients apply to reptiles as well.  Some snake carcasses tested positive for
chlorpyrifos in two of the three field studies.  The presence of chlorpyrifos in snake carcasses
suggests the possibility of secondary toxicity, that is, effects caused by a chemical present in  the
carcass of an animal eaten by a predator.

                     3) Risks to Bees and Beneficial Insects

       Chlorpyrifos is highly acutely toxic to honey bees and applications would be expected to
pose a risk to bees and beneficial insects present in the treated area during application. At
present, there is no accepted method to determine risk quotients based on the bee acute contact
toxicity data. Results from some field studies confirm predicted risks to bees, which are killed if
present during application and for as long as  24 hours after treatment.

                     4) Risks to Fish and Amphibians

       Risk quotients exceed the LOG for high acute (0.5)  and chronic (1.0) effects for
freshwater and estuarine fish for all uses.  Reproductive risks to fish populations are indicated by
risk quotients which are greater than 21-day EECs for all uses.  Freshwater fish reproductive
effects seen in the fathead minnow include reduced survival at 1.09 ppb; for estuarine fish,
reproductive effects include reduced survival and body weight at 0.28 ppb.  Fish reproductive
effects are likely to be greater than indicated by RQ values  presented in risk quotient tables for
all chlorpyrifos uses. The fathead minnow tested in the full life-cycle study is less sensitive on
an acute basis than other species, such as bluegill and trout. Thus the RQs for more  sensitive
fish would be expected to be greater than for the fathead minnow.

                                            50

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                    5) Risks to Aquatic Invertebrates

       Risk quotients for all uses exceed the acute and chronic LOCs for freshwater and
estuarine invertebrates. For 14 major crop uses, eight of the fourteen peak EECs exceed the
EC50/LC50 values for three of the four freshwater species. In the estuarine/marine invertebrate
life cycle toxicity study using mysid shrimp, reproductive effects were seen at 0.0046 ppb, the
lowest dose tested. Effects observed were a reduced number of young and reduced mean number
of young per female.

                    6) Risks to Freshwater Organisms in Field Monitoring Studies

       In an Iowa corn field study, chlorpyrifos was applied as an emulsifiable concentrate to
four fields (4 applications per field, 1.5-3 Ibs. ai/A) and as a granular formulation to four fields
(3 applications per field, 1-2.6 Ibs. ai/A). Chlorpyrifos levels were measured in aquatic areas
adjacent to the treated fields. The mean residue level of 66.9 ppb exceeds all predicted EECs.
After granular treatment to corn at 2 Ibs. ai/A, one water sample had residue level of 1.80 ppb
seven days after the tassel broadcast treatment.  This concentration is below predicted EECs
ranging from 5.5 to 8.6 ppb.

       In a California citrus field study, two orange groves were sprayed by airblast, and
chlorpyrifos concentrations measured in soil, crop and non-crop foliage, invertebrates and water
adjacent to the groves.  Modeled EECs were generally comparable to measured concentrations.
Measured chlorpyrifos levels in water ranged from 1.041 to 486 ppb, depending upon the
application scenario. More detailed information can be found in the Environmental Fate and
Effects Assessment, June 2000. Dead fish and other aquatic vertebrates were found in ponds
adjacent to treated groves on several occasions.

       A field study in Florida measured chlorpyrifos levels after two applications to golf course
turf at 4 Ibs. ai/A, with a 21-day interval between applications.  Applications were made using
both granular and liquid sprays. For areas treated with the liquid formulation, measured initial
mean concentrations in water were <1.0 ppb (non-detect). The predicted Tier I EEC was 14.75
ppb, and the Tier II EEC was 29.03 ppb.  For the granular formulation, the measured initial mean
concentrations were <1.0 ppb (non-detect) and 0.905 ppb. The predicted Tier I EECs were 13.28
ppb; the Tier II EEC was 25.31 ppb. Thus, measured chlorpyrifos concentrations were below
modeled estimates.

       Monitoring results from the early 1990s indicate widespread and persistent occurrence of
chlorpyrifos in aquatic areas throughout the nation.  In a national fish monitoring study
approximately 23 percent of the fish nationwide had measurable levels of chlorpyrifos residues
(EPA 1992). Chlorpyrifos was detected at levels up to 59 ppb in mussels in coastal California,
and in concentrations of 245 ppb in sediments in Massachusetts (NOAA, 1992). The Agency's
Storet database reports measurable chlorpyrifos levels in biota in 12 states and in one water
sample. It is uncertain whether the chlorpyrifos levels in aquatic organism tissues are sufficient
to adversely affect exposed organisms.

                                           51

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       Chlorpyrifos was detected in storm water runoff in the San Francisco Bay area in 1994-
1995 at levels that exceed the California Department of Fish and Game water quality criterion of
15 ng/L (pptr). Approximately 80 percent of the samples collected from Sacramento and
Stockton exceeded the water quality criterion.  In the San Francisco Bay area, approximately 75
percent of the samples collected exceeded the water quality criterion. Rainfall samples also
collected in the San Francisco area contained chlorpyrifos at levels toxic to Ceriodaphnia.

                    7) Risks to Piscivorous Birds and Mammals from Bioconcentration of
Chlorpyrifos in the Food Chain

       At high application rates, chlorpyrifos levels in fish and aquatic invertebrates could
exceed the avian subacute dietary toxicity value (136 ppm) and reproductive NOAELs for birds
(25 ppm) and mammals (10 ppm).

                    8) Risks to Nontarget Plants

       Plant toxicity studies are not currently required for insecticides.  However, chlorpyrifos
toxicity data are available for one out of five recommended aquatic plant species. Based on
toxicity values for three estuarine algal species (only one recommended species), risk quotients
for the highest exposures do not exceed any level of concern.  However, the EC50 for all three
algal species were exceeded by measured chlorpyrifos levels in some water samples found in the
citrus field study.

              3. Risk Characterization of TCP

       A full set of acute studies has been submitted using TCP as the test substance. Studies
indicate that TCP's acute toxicity ranges from moderately toxic to practically non-toxic. TCP is
less acutely toxic than chlorpyrifos, hence risks to fish and wildlife would appear to be reduced
as chlorpyrifos degrades.

              4. Risk Quotients for Major Use Sites

                    a. Corn

       Corn is the largest use site for chlorpyrifos in terms of pounds of active ingredient
applied per year.  The Agency estimates that for the years 1987-1999, an average of
approximately 5.5 million Ibs. ai per year were applied to corn. Based on that usage data,
chlorpyrifos was applied to approximately 7% of corn grown in the U.S. A typical application
on corn is an  at-plant granular treatment at 1.1 Ibs. ai/A.

       Wildlife utilization of corn fields is high with a broad diversity of avian and mammalian
species. Wildlife reported to feed in corn fields include quail, grouse, partridge,  pheasant, prairie
chicken, ducks, doves, songbirds, red fox, muskrat, opossum, raccoon and deer.  Bobwhite quail,
pheasant and  rabbits also nest and brood young in corn fields.

                                           52

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       Applications of spray and granular formulations to corn result in risk quotients which
indicate acute risks to small terrestrial mammals, birds and aquatic organisms, except estuarine
algae.  In a field study evaluating use on corn, forty-four carcasses collected in and around the
treated site.  Seven carcasses were analyzed for chlorpyrifos and three carcasses were found to
contain residues of chlorpyrifos.  The field study did not monitor for aquatic effects, but
measured chlorpyrifos residues at a mean level of 66.9 ppb adjacent to treated fields.

       A comparison of risk quotients for various application scenarios in Table 22 indicates
that risks are lowest with the ground application. Approximately 98% of chlorpyrifos use on
corn is by ground application.  Risk quotients for aquatic species from a ground application are
about 28% lower than for a single aerial application at the same application rate. Aquatic risks
in shallow ponds (2 meters deep) will be greater than in deeper ponds (3 meters deep); risks are
higher in standing waters, marshes and  swamps than they are in shallow ponds.

       Granular treatments to corn at pre-plant,  at plant, at cultivation, whorl and tassel stages
indicate high risks to many species from all four treatment scenarios. Risk quotients exceed the
high risk LOCs for all wildlife categories, except mammals weighing 1,000 grams.

             Table 22. Ranges of Risk Quotients for Chlorpyrifos Use on Corn
Application Method
Ground spray,
preplant, 1 app.@ 3
Ibs. ai/A, 2" soil
incorporation
Ground spray,
postemergence/ foliar,
1 app. @ 1.5 Ibs. ai/A
Aerial spray,
postemergence/foliar,
1 app. @ 1.5 Ibs. ai/A
Ground spray,
postemergence/ foliar,
3 apps. @ 1.5 Ibs.
ai/A, 14-day intervals
Exposure
Scenario
Acute
Subacute
Reproduction
NOAEL/NOAEC
Acute
Subacute
Reproduction
NOAEL/NOAEC
Acute
Subacute
Reproduction
NOAEL/NOAEC
Acute
Subacute
Reproduction
NOAEL/NOAEC
Mammals
0.014-7.1
0.03-0.54
4.5-26
0.007-3.5
0.02-0.27
2.3-13
0.007 -
3.5
0.017-
0.27
2.3-36
0.009-4.6
0.02-0.35
3-17
Birds
~
0.33-5.3
1.8-19
~
0.17-2.6
0.92-5
~
0.17-
2.6
0.92- 14
~
0.22-3.5
1.2-6.7
Fresh-
water
Fish
1.5
~
2.2-3.8
3.1
~
4.7-8.4
4.3
~
6.7 - 12
13
~
21-38
Aquatic
Inverts.
28
~
32-54
55
~
68-120
77
~
95-
170
240
~
290-
540
Estuar-
ine Fish
2.9
~
4.6-7.8
5.7
~
9.6-17
8
~
14-24
25
~
42-77
Estuarine
Inverts.
79
~
>280-
>470
160
~
>590->1000
220
-
>830>
1500
690
~
>2500-
>4700
                                            53

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Application Method
Aerial spray,
postemergence/ foliar,
11 apps. @ 1 Ib. ai/A,
3 -day intervals
Granular, ground
broadcast, preplant, 1
app. @ 1.1 Ibs. ai/A,
4" soil incorporation
(typical rate, modeled
on Iowa soil)
Granular, ground
broadcast, preplant, 1
app. @ 1.1 Ibs. ai/A,
4" soil incorporation
(typical rate, modeled
on Mississippi soil)
Granular, ground
broadcast, preplant, 1
app. @ 2 Ibs. ai/A, 4"
soil incorporation
Granular, at-plant, 7"
band or T-band, 1
app. @ l.Soz/1000
row feet, 1" soil
incorporation
Granular,
postemergence aerial
broadcast, 2 apps. @
0.975 ai/A, 14-day
intervals, 50%
interception by plant
Exposure
Scenario
Acute
Subacute
Reproduction
NOAEL/NOAEC
Acute
Reproduction
NOAEL/NOAEC
Acute
Reproduction
NOAEL/NOAEC
Acute
Reproduction
NOAEL/NOAEC
Acute
Reproduction
NOAEL/NOAEC
Acute
Reproduction
NOAEL/NOAEC
Mammals
0.017-8.8
0.04-0.68
5.6-90
0.018-
1.1
~
0.018-
1.1
~
0.032-2.1
NA2
0.13-8.5
~
0.05-3.3
~
Birds
~
0.41-6.6
2.2-36
6.1
-
6.1
-
11
~
46
-
18
-
Fresh-
water
Fish
19
~
42-49
0.54
0.77-
1.4
1.5
2.3-
3.9
0.92
1.4-2.5
3.7
5.9-10
3.5
5.4-9.6
Aquatic
Inverts.
340
~
590-
700
9.8
11 -19
27
32-55
17
20-36
66
84-140
64
78-140
Estuar-
ine Fish
35
~
85-100
1.0
1.6-
2.8
2.8
4.6-
7.9
1.7
2.9-5.1
6.9
12-21
6.6
11-20
Estuarine
Inverts.
970
~
>5200
>6100
28
>95 >167
77
>280
>480
47
>180
>310
190
>730
>1300
180
>670
>1200
                   b. Cover Crops
      Risk quotients for alfalfa, clover and grass grown for seed, mint and wheat are
summarized in Table 23. Chlorpyrifos applications to these crops are largely limited to liquid
formulations.  Runoff from foliar applications to cover crops is expected to be lower than to
crops grown on plowed or bare ground. The GENEEC and PRZM3-EXAMS Models estimate
EECs for row crops, but data on runoff are unavailable to model EECs for vegetative ground
cover. The degree to which ground cover reduces runoff and yields lower EECs is unknown.
                                         54

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Hence, the aquatic risk quotients in the following tables for these cover crops are higher than
would actually be anticipated

       Alfalfa is the major use site in this group. Alfalfa fields are heavily utilized by a
diversity of avian and mammalian species. Ring-necked pheasants, grouses, partridges, quail,
sandhill crane, ducks, geese, mourning dove, songbirds, rabbits, groundhogs, muskrats, deer and
elk feed in alfalfa fields to a moderate to high degree.  Many of the avian species also nest in
alfalfa fields.
        Table 23. Ranges of Risk Quotients for Chlorpyrifos Use on Cover Crops
                (Alfalfa, Clover and Grass Grown for Seed, Mint, Wheat)
Crop and
Application Method
Alfalfa, granular,
at-plant, in-
furrow, 1 app. @
1 Ib. ai/A, 4" soil
incorporation
Alfalfa, aerial
spray,
postemergent/
foliar, 4 apps. @
1 Ib. ai/A, 42-day
interval
Alfalfa, aerial
spray,
postemergence/
foliar, 1 app. @
0.7 Ibs. ai/A
Clover grown for
seed, ground
spray, preplant
and foliar, 2 apps.
@ 2 Ibs. ai/A, 14-
day interval
Grass grown for
seed, aerial spray,
foliar, 3 apps. @
1 Ib. ai/A, 7-day
intervals
Exposure Scenario
Acute
Reproduction
NOAEL/NOAEC
Acute
Subacute
Reproduction
NOAEL/NOAEC
Acute
Subacute
Reproduction
NOAEL/NOAEC
Acute
Subacute
Reproduction
NOAEL/NOAEC
Acute
Subacute
Reproduction
NOAEL/NOAEC
Mammals
0.016-1.1
-
0.005-2.4
0.011-0.18
1.5-8.5
0.003-1.6
0.008 -
0.13
1.1-6
0.012-5.9
0.25-0.45
8.8-21
0.008-4.1
0.18-0.32
6.2-15
Birds
5.7
~
~
0.11-1.8
0.6-3.4
~
0.08-1.2
0.42-2.4
~
2.5-4.4
3.6-8.5
~
1.7-3.1
2.4-6
Fresh-
water Fish
3.5
0.7-1.3
10
~
15-28
2
~
3-5.5
8.3
~
13-23
9.4
~
14-26
Aquatic
Inverts.
8.3
10-18
180
~
220-400
36
~
52-78
150
~
180-
320
170
~
200-
380
Estuar-
ine Fish
0.86
1.4-2.6
19
~
31-57
3.7
~
6.1-11
16
~
26-46
18
~
29-54
Estuarine
Inverts.
24
>87 >160
510
~
>1900
>3500
100
~
>370
>680
430
~
>1600
>2800
490
~
>1700
>3300
                                           55

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Crop and
Application Method
Mint, ground
spray, foliar, 1
app. @ 2 Ibs. ai/A
Wheat, aerial
spray, foliar, 2
apps. @ 0.5 Ib.
ai/A, 7-day
interval
Winter wheat,
aerial spray,
foliar, 1 app. @
0.47 Ib. ai/A
(typical)
Exposure Scenario
Acute
Subacute
Reproduction
NOAEL/NOAEC
Acute
Subacute
Reproduction
NOAEL/NOAEC
Acute
Subacute
Reproduction
NOAEL/NOAEC
Mammals
0.009-4.7
0.023-0.36
3-17
0.004-1.8
0.01-0.14
1.3-6.4
0.002-1.1
0.005 -
0.085
0.18-3.9
Birds
~
0.22-3.5
1.2-6.7
~
0.096-1.3
0.52-2.6
~
0.05-0.83
0.07 - 1.6
Fresh-
water Fish
4.1
~
6.5-11
3.1
~
4.6-8.6
1.3
~
2-3.7
Aquatic
Inverts.
74
~
93-160
55
~
65-120
24
~
28-53
Estuar-
ine Fish
7.7
~
13-23
5.7
~
9.3-18
2.5
~
4-7.6
Estuarine
Inverts.
210
~
>810
>1400
160
~
>570
>1100
69
~
>240
>460
                     c. Peanuts

       Risk quotients for use on peanuts are shown in Table 24. About 1.5 percent of total
chlorpyrifos poundage is used on peanuts and is applied to 10-15 percent of the approximately
1,600,000 acres of peanuts in the U.S. The granular formulation is the primary treatment on
peanuts.  The Agency estimates that the typical use rate is 1.1 granular applications at an average
of 1.8 Ibs ai/A on approximately 160,000 to 240,000 acres. The leading states using chlorpyrifos
in decreasing order of poundage are Georgia, North Carolina, Virginia and Alabama. The
registrant has agreed to eliminate the granular aerial spraying of peanuts. Therefore, the risk to
wildlife from the aerial spraying of granulars will be eliminated.

       Wildlife utilization of peanut fields is relatively high with a fair diversity of avian and
mammalian species.  Wildlife reported to feed with moderate to high frequency in peanuts fields
include bobwhite quail, doves, songbirds, waterfowl, wild turkey, rabbits, squirrels, raccoons,
opossum, and deer.  Bobwhite quail is the only species specifically listed as nesting in peanut
fields.
                                            56

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            Table 24. Range of Risk Quotients for Chlorpyrifos Use on Peanuts
Application Method
Ground spray,
preplant, 1 app. @ 2
Ibs. ai/A, 4" soil
incorporation
Granular, 6" band,
at-plant, 1 app. @
2.25 oz ai/1000 ft,
4" soil incorp.
(typical)
Granular, aerial
broadcast, early
pegging, 1 app. @
1.95 Ibs ai/A
Spray (preplant, 4"
incorporation)
followed by
granular (early
pegging, aerial
broadcast), 2 apps.
@ 2 Ibs. ai/A, 40-
day interval
Exposure
Scenario
Acute
Subacute
Reproduction
NOAEL/NOAEC
Acute
Reproduction
NOAEL/NOAEC
Acute
Reproduction
NOAEL/NOAEC
Acute
Reproduction
NOAEL/NOAEC
Mammals
0.009-4.7
0.023-0.36
3-17
0.2-13
-
0.21-13
-
NA1
NA
Birds
~
0.22-3.5
1.2-6.7
68
-
71
-
NA
NA
Fresh-
water
Fish
1.4
~
2.2-3.8
1.4
2.2-3.8
0.92
1.5-2.5
5.2
7.5-13
Aquatic
Inverts.
24
~
31-54
25
32-54
17
21-36
94
110-180
Estuar-ine
Fish
2.5
~
4.4-7.8
2.6
4.5-7.8
1.7
3-5.1
9.8
15-26
Estuarine
Inverts.
70
~
>270
>470
71
>270
>470
47
>180
>320
270
>930
>1600
1 The Agency currently has no methodology for assessing risks from a combination of spray and granular
formulations for terrestrial organisms.  Therefore, only aquatic risks were assessed for this scenario.

                     d. Cotton

       Risk quotients for use on cotton are shown in Table 25.  The major chlorpyrifos use
pattern on cotton is six foliar spray applications per season. The Agency estimates that about 3.2
percent of the total chlorpyrifos use is applied to up to 6 percent of the approximately 12,400,000
acres of cotton in the U.S. The typical average chlorpyrifos usage on cotton is 1.7 applications at
0.6 Ibs ai/A on approximately 640,000 to 800,000 acres.  The leading states using about 84
percent of the chlorpyrifos applied to cotton in decreasing order of poundage are Arizona,
Mississippi, and California, Texas, and Louisiana.

       Wildlife utilization of cotton fields is low to moderate. Wildlife that feed in cotton fields
include quail, pheasant, doves, songbirds, rabbits, raccoon,  and deer with a low to high degree of
use. Bob white quail, pheasant (brood-rearing), and rabbits  also nest and brood young in cotton
fields.
                                            57

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            Table 25. Range of Risk Quotients for Chlorpyrifos Use on Cotton

Application Method

Aerial spray,
foliar, 6 apps. @
1 Ib. ai/A, 3-day
intervals


Aerial spray,
foliar, 1 app. @
0.6 Ib. ai/A



Exposure
Scenario

Acute

Subacute

Reproduction
NOAEL/NOAEC
Acute

Subacute

Reproduction
NOAEL/NOAEC

Mammals

0.015-7.6

0.036-
0.58
4.9-28

0.002-1.2

0.007 -
0.09
0.75-4.2


Birds

~

0.36-5.7

1.9-11

~

0.055-
0.89
0.3-1.7

Fresh-
water Fish

15

~

30-40

0.77

~

1.1-1.9

Aquatic
Inverts.

270

~

340-570

14

~

15-28


Estuarine
Fish
28

~

62-82

1.5

~

2.1-3.9

Estuarine
Inverts.

780

~

>3800
>5000
40

~

>130
>240
                    e. Citrus

       Risk quotients for use on citrus are shown in Table 26. Citrus use represents about 3
percent of the total chlorpyrifos poundage.  Chlorpyrifos is applied to oranges on about 60
percent of the total US acreage; grapefruit on about 12-16 percent or approximately 23,000 to
32,000 acres; lemons on about 30-43 percent or approximately 19,000 to 27,000 acres; and other
citrus (including kumquats, limes, tangelos and tangerines) on about 16-32 percent of the total
US acreage or about 8,000 to 16,000 acres. Maximum and typical risks for chlorpyrifos on citrus
are assessed only for applications to oranges, because oranges represent the highest use rate and
largest acreage of any citrus crop.

       Wildlife utilization of citrus groves ranges from low to high for a diversity of avian and
mammalian  species (Gusey and Maturgo 1973).  Mammals reported to feed moderately in citrus
groves include raccoons and  deer.  Mourning doves, pheasants and 13 species of birds are listed
as nesting in citrus groves. During the California orange field study in which two airblast
applications were made, between 188 to 561 birds were observed in orange groves. Wildlife
carcasses with chlorpyrifos residues found in the field study included a mockingbird, ground
squirrel, pocket gopher and a western rattlesnake.
                                           58

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            Table 26. Range of Risk Quotients for Chlorpyrifos Use on Citrus
Application Method
Airblast spray,
foliar, 2 apps.
@3.5 Ibs. ai/A,
30-day interval,
5% spray drift
Ground spray or
sprinkler
irrigation, 10
apps. @ 1 Ib ai/A,
7-day interval
Airblast spray,
foliar, 1 app. @ 6
Ibs. ai/A, 5%
spray drift
Exposure
Scenario
Acute
Subacute
Reproduction
NOAEL/NOAEC
Acute
Subacute
Reproduction
NOAEL/NOAEC
Acute
Subacute
Reproduction
NOAEL/NOAEC
Mammals
0.017-8.7
0.041-
0.66
5.5-88
0.08-2.6
0.02-0.2
3-27
0.028-14
~
0-140
Birds
~
0.4-6.5
2.2-35
~
0.22-2
1.2-11
~
0.66-11
3.6-58
Fresh-
water Fish
21
~
33-54
19
~
30-53
17
~
27-48
Aquatic
Inverts.
370
~
470-770
340
~
420-750
310
~
390-690
Estuarine
Fish
39
~
67-110
35
~
61-110
32
~
56-99
Estuarine
Inverts.
1100
~
>4100
>6700
970
~
>3700
>6500
880
~
>3400
>6000
                    f. Golf Course Turf

       Risk quotients for use on golf course turf are shown in Table 27. The volume of
chlorpyrifos applied nationally on golf course turf and typical use rates have not been reported.
Comparison of risk quotients for spray and granular applications on golf course turf at the same
use rates suggest that the granular formulation is more acutely toxic to birds, mammals and other
terrestrial species, while the spray formulation is only slightly more toxic to aquatic species. It is
important to note that the risk quotients shown in Table 27 are based on application at the rate of
4 Ibs. ai/A.  Mitigation agreed to in June 2000 reduced the maximum application rate on golf
course  turf to 1 Ib. ai/A.  Therefore, actual RQs will be considerably lower than those shown
below.
      Table 27.  Range of Risk Quotients for Chlorpyrifos Use on Golf Course Turf(a)
Application Method
Ground spray, 2
apps. @ 4 Ibs.
ai/A, 30-day
interval
Exposure
Scenario
Acute
Subacute
Reproduction
NOAEL/NOAEC
Mammals
0.097-9.9
0.43-0.76
57-100
Birds
~
4.2-7.4
23-58
Fresh-
water Fish
16
~
26-456
Aquatic
Inverts.
290
~
370-640
Estuarine
Fish
30
~
52-91
Estuarine
Inverts.
830
~
>3200
>5500
                                          59

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Application Method
Granular, soil
broadcast, 2 apps.
@ 4 Ibs. ai/A, 30-
day interval
Exposure
Scenario
Acute
Subacute
Reproduction
NOAEL/NOAEC
Mammals
0.43-28
~
NA
Birds
~
150
~
Fresh-
water Fish
14
~
22-39
Aquatic
Inverts.
250
~
320-550
Estuarine
Fish
26
~
46-79
Estuarine
Inverts.
720
~
>2800
>4800
(a) Mitigation agreed to in June, 2000, reduced the maximum application rate to golf course turf to 1 Ib. ai/A.
Therefore, actual RQs will be considerably lower than those shown.
       Risk quotients for use on other, minor crops can be found in the Environmental Fate and
Effects Assessment, June 8, 2000, located in the public docket and on the internet at
www.epa.gov/pesticides/op.

              5. Incidents

       Bird kills involving mallard ducklings, geese, other waterfowl, robins and a bluebird
have been reported for chlorpyrifos, most of which occurred following golf course and lawn
treatments.  These incidents were reported between 1974 and 1992.  In some cases, carcass
analysis detected more than one pesticide per carcass. Determination of the presence of
chlorpyrifos in an animal or carcass only indicates that the animal was exposed.

       Aquatic mortality incidents have also been reported, most of which were related to
perimeter applications around residences. Incidents were reported between 1975 and 1992.

       The preceding assessment indicates potential risks of concern to nontarget species.
However, it should be noted that some mitigation measures implemented as a result of the June
2000 agreement are not reflected in the assessment. For example, all outdoor residential uses
and most outdoor non-residential uses have been eliminated. The few remaining outdoor uses,
golf courses, road medians and industrial plant sites are now limited to 1 Ib. ai/A (reduced from
4 Ibs. ai/A).  These measures are expected to result in significant reductions in the levels of
chlorpyrifos in surface water, particularly in urban areas.

       To address ecological risk from the agricultural uses of chlorpyrifos, additional measures
including rate  reductions, aquatic buffer zones, seasonal limits and increased intervals between
applications will be needed.  These are outlined in the following section.
                                           60

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IV. Interim Risk Management and Reregistration Decision

       A. Determination of Interim Reregistration Eligibility

       Section 4(g)(2)(A) of FIFRA calls for the Agency to determine, after submissions of
relevant data concerning an active ingredient, whether products containing the active ingredient
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 the active ingredient chlorpyrifos.

       The Agency has completed its assessment of the occupational and ecological risks
associated with the use of chlorpyrifos, as well as a chlorpyrifos-specific dietary risk assessment
that has not considered the cumulative effects of organophosphates as a class. Based on a review
of these data and public comments on the Agency's assessments for the active ingredient
chlorpyrifos, EPA has sufficient information on the human health and ecological effects of
chlorpyrifos to make interim decisions as part of the tolerance reassessment process under
FFDCA and reregistration under FIFRA, as amended by FQPA.  Taking into account both risks
and benefits, the Agency has determined that, with the exception of open-pour dust formulations
for fire ant control, products containing chlorpyrifos uses are eligible for reregistration provided
that: (i) current data gaps and additional data needs are  addressed; (ii) the risk reduction
measures outlined in this document as well as those in the Memorandum of Agreement of June
2000 are adopted, and label amendments are made to reflect these measures; and (iii) cumulative
risks considered  the organophosphates support a final reregistration eligibility decision. Label
changes are  described in Section IV. Appendix B  identifies the generic data requirements that
the Agency reviewed as part of its interim determination of reregistration eligibility of
chlorpyrifos products, and lists the submitted studies that the Agency found acceptable.

       Although the Agency has not yet considered cumulative risks of the organophosphates,
the Agency is issuing this interim assessment now in order to identify risk reduction measures
that are necessary to support the continued use of chlorpyrifos.  Based on its current evaluation
of chlorpyrifos alone, the Agency has determined that chlorpyrifos products, unless labeled and
used as specified in this document, would present risks inconsistent with FIFRA.  Accordingly,
should a registrant fail to implement appropriate risk mitigation measures, the Agency will take
regulatory action to address the risk concerns from use of chlorpyrifos.

       At the time that a cumulative assessment is conducted, the Agency will address any
outstanding risk  concerns. For chlorpyrifos, if all changes outlined in this document are
incorporated into the labels, risks will be mitigated to acceptable levels taking into account the
benefits of chlorpyrifos use where appropriate. But, because this is an interim RED, the Agency
may take further actions, if warranted, to finalize the reregistration eligibility decision for
chlorpyrifos products after assessing the  cumulative risk of the organophosphate class. Such an
incremental  approach to the reregistration process  is consistent with the Agency's goal of
improving the transparency of the reregistration  and tolerance reassessment processes.  By

                                           61

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evaluating each organophosphate in turn and identifying appropriate risk reduction measures, the
Agency is addressing the risks from the organophosphates in as timely a manner as possible.

       Because the Agency has not yet considered cumulative risks for the organophosphates,
this reregi strati on eligibility decision does not fully satisfy the reassessment of the existing
chlorpyrifos food residue tolerances as called for by FQPA.  When the Agency has considered
cumulative risks, chlorpyrifos tolerances will be reassessed in that light. At that time, the
Agency will reassess chlorpyrifos along with the other organophosphate pesticides to complete
the FQPA requirements and make a final reregi strati on eligibility determination. By publishing
this interim decision on reregi strati on eligibility and requesting mitigation measures now for the
individual chemical chlorpyrifos, the Agency is not deferring or postponing FQPA requirements;
rather, EPA is taking steps to assure that uses which EPA has already determined exceed
FIFRA's unreasonable risk standard do not remain on the label, pending completion of
assessment required under the FQPA. This decision does not preclude the Agency from making
further FQPA determinations and tolerance-related rulemakings that may be required on this
pesticide or any other in the future.

       If the Agency determines, before finalization of the RED, that any of the determinations
described in this interim RED are no longer appropriate, the Agency will pursue appropriate
action, including but not limited to, reconsideration of any portion of this interim RED.

       B. Regulatory Position

             1. FQPA Assessment

                    a. "Risk Cup" Determination

       As part of the FQPA tolerance reassessment process, EPA assessed the risks associated
with this organophosphate.  The assessment is for this individual organophosphate, and does not
attempt to fully  reassess these tolerances as required under FQPA.  FQPA requires the Agency to
evaluate food tolerances on the basis of cumulative risk from substances sharing a common
mechanism of toxicity, such as the toxicity expressed by the organophosphates through a
common biochemical interaction with the cholinesterase enzyme.  The Agency will evaluate the
cumulative risk posed by the entire class of organophosphates once the methodology is
developed and the policy concerning cumulative assessments is resolved.

       EPA has determined that risk from exposure to chlorpyrifos is within its own "risk cup."
In other words, if chlorpyrifos did not share a common mechanism of toxicity  with other
chemicals, EPA would be able to conclude today that the tolerances for chlorpyrifos meet the
FQPA safety standards. In reaching this determination EPA has considered the available
information on the special sensitivity of infants and children, as well as the chronic and acute
food exposure.  An aggregate assessment was conducted for exposures through food, residential
uses and drinking water. Results of this aggregate assessment indicate that the human health
risks from these combined exposures are considered to be within acceptable levels; that is,

                                          62

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combined risks from all exposures to chlorpyrifos "fit" within the individual risk cup.  Therefore,
except for tolerances that will be revoked as indicated in Tables 28 and 29, the chlorpyrifos
tolerances remain in effect and unchanged until cumulative risks from all organophosphates are
considered.
              b. Tolerance Summary

       In the individual assessment, established tolerances for residues of chlorpyrifos in/on raw
agricultural, animal, and processed food/feed commodities [40 CFR §180.241] are presently
expressed in terms of either the combined residues of chlorpyrifos and its metabolite 3,5,6-
trichloro-2-pyridinol (TCP) or as chlorpyrifos per se.  The Agency has determined that residues
of TCP are not of concern for dietary risk and can therefore be excluded from the tolerance
expression. The tolerance levels should be amended to reflect residues of chlorpyrifos per se.
Based on the Agency's decision to change the tolerance expression, the tolerances listed in 40
CFR need to be reorganized as shown in Table 28. A summary of the tolerances is included in
Table 29.

                 Table 28. Reorganization of Tolerances for Chlorpyrifos

40 CFR
§ 180.342 (a)(l)
§ 180.342 (a)(2)
§180.342(a)(3)
§180.342(a)(4)
§180.342 (c)(l)
§ 180.342 (c)(2)
Current Tolerance
Expression [Restrictions]
Chlorpyrifos and TCP.
Chlorpyrifos per se.
[Provisions on safe use of
chlorpyrifos on food-handling
establishments].
Chlorpyrifos per se (tolerances
established in food items [other than
those already covered by a higher
tolerance as a result of use on
growing crops] in food-service
establishments, as result of the
application of microencapsulated
form.
Chlorpyrifos and TCP
[For regional registrations].
Chlorpyrifos per se
[For regional registrations].
Tolerance Reassessment*
40 CFR
§180.342 (a)(l)
§180.342 (a)(l)
§180.342(a)(2)
§180.342(a)(3)
§180.342 (c)

Tolerance Expression [Restrictions]
Chlorpyrifos per se.
Transfer all tolerances under this
section to §180.342 (a)(l) at their
respective proposed levels.
Conditions for safe use of chlorpyrifos
on food-handling establishments.
Redesignate as §180.342(a)(2).
Chlorpyrifos per se.
Redesignate as §180.342(a)(3).
Chlorpyrifos per se
[For regional registrations].
Delete §180.342 (c)(2) section since
all tolerances under this section are to
be revoked (no registered uses).
* The term "reassessed" here is not meant to imply that the tolerance has been reassessed as required by FQPA, since this
tolerance may be reassessed only upon completion of the cumulative risk assessment of all organophosphates, as required by this
law. Rather, it provides a tolerance level for this single chemical, if no cumulative assessment was required, that is supported by
all of the submitted residue data.
                                             63

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Table 29. Tolerance Summary for Chlorpyrifos.
Commodity 	
Current
Tolerance
(ppm)
Tolerance
Reassessment*
(ppm)
[Correct Commodity Definition]/
Comments
Tolerances Listed Under 40 CFR §180.342(a)(l)
Alfalfa, forage
Alfalfa, hay
Almonds
Almonds, hulls
Apple, pomace, wet
Apples
Aspirated grain
fractions
Bananas, whole
Bananas, pulp with peel
removed
Bean, forage
Beans, lima
Beans, lima, forage
Beans, snap
Beans, snap, forage
Beets, sugar, molasses
Beets, sugar, pulp (dried)
Beets, sugar, roots
Beets, sugar, tops
Blueberries
Broccoli
Brussels sprouts
Cabbage
Caneberries
Cattle, fat
Cattle, meat and meat
byproducts
3
13
0.2
12.0
None
1.5
None
0.1
0.01
0.7
0.05
1.0
0.05
1.0
15.0
5.0
1.0
8.0
2(l)a
1
1
1
1.0
0.3
0.05
0.05
3
13
0.2
12.0
0.02
0.01
TBD
0.1
0.01
Revoke
Reassign
Revoke
Reassign
Revoke
15.0
5.0
1.0
8.0
Revoke
Reassign
Reassign
Reassign
Revoke
0.3
0.05
0.05


[Almond].
[Almond, hulls].
[Apple, wet pomace]
Proposed tolerance (0.01 ppm) and average concentration
factor (2.1).
[Apple].The registrant has submitted a rebuttal to the
modification of this tolerance. This rebuttal is under
review.
[Grain, aspirated grain fractions] .
A 0.5 ppm tolerance was recommended for com aspirated
grain fractions based on a concentration factor of ~ lOx in
the <420 M dust fraction (see CBRS No. 11372, D188151,
S. Knizner, 8/26/93). Additional data are required for
sorghum, soybean, and wheat aspirated grain fractions
before a tolerance for aspirated grain fractions can be
established (see "Aspirated Grain Fractions (Grain Dust):
A Tolerance Perspective", E.Saito and E.Zager, 6/7/94.


Not a feed item Table 1 (OPPTS 860.1000)
Covered by legume vegetables group.
Not a food/feed item.
Covered by legume vegetables group.
Not a food/feed item.
[Beet, sugar, molasses].
[Beet, sugar, dried pulp].
[Beet, sugar, roots].
[Beet, sugar, tops].
No registered uses exist.
Covered by Vegetable, Brassica, leafy, group.
Covered by Vegetable, Brassica, leafy, group.
Covered by Vegetable, Brassica, leafy, group.
No registered uses exist.

[Cattle, meat]
\Cattle, meat byproducts]
                     64

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Commodity
Cauliflower
Cherries
Chinese cabbage
Citrus fruits
Citrus oil
Citrus pulp, dried
Clover, forage
Clover, hay
Com, fresh (inc. sweet K-
CWHR)
Com, field, grain
Com, forage
Com, fodder
Com oil
Cotton, gin byproducts
Cottonseed
Cranberries
Cucumbers
Eggs
Figs
Filbert
Goats, fat
Goats, meat and meat
byproducts
Grass, forage
Grass, hay
Grass, seed screenings
Hogs, fat
Hogs, meat
Current
Tolerance
(ppm)
1
1
1
1.0
25.0
5.0
None
None
0.1
0.05
8
8
8
8
3.0
None
0.2
1.0
0.05
0.01
0.01
None
0.2
0.05
0.05
None
None
None
0.2
0.05
0.05
Tolerance
Reassessment*
(ppm)
Reassign
TBD
TBD
Reassign
1.0
20
5.0
TBD
TBD
0.05
0.05
8
8
8
8
0.25
TBD
0.2
1.0
0.05
0.01
0.01
0.2
0.2
0.05
0.05
TBD
TBD
TBD
0.2
0.05
0.05
[Correct Commodity Definition]/
Comments
Covered by Vegetable, Brassica, leafy, group.
[Cherries, sweet] Additional data and/or label revisions are
required.
[Cherries, tart] Additional data and/or label revisions are
required.
Covered by Vegetable, Brassica, leafy, group.
\Fruit, citrus, group].

\Citrus, dried pulp].


[ Corn, sweet , kernel plus cob -with husks removed}.

\Corn, field, forage]
\Corn, s-weet, forage]
\Corn, field, stover]
\Corn, s-weet, stover]
[Corn, field, refined oil]!
Recommended tolerance based on a average concentration
factorof3.3x(seeCBRSNo. 11372, D188151, S.
Knizner, 8/26/93).

\Cotton, undelinted seed}
\Cranberry]
\Cucumber]
\Egg]
\Fig]
\Filbert] Use previously covered under tree nuts.
\Goat, fat]
\Goat, meat]
\Goat, meat byproducts]



[Hog, fatl
[Hog, meat]
[Hog, meat byproducts!
65

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Commodity
Horses, fat
Horses, meat
Kiwifruit
Legume vegetables,
succulent or dried (except
soybeans)
Lettuce
Macadamia nut
Milk, fat
Milk, whole
Mint, hay
Mushrooms
Nectarines
Onions (dry bulb)
Pea forage
Peaches
Peanuts
Pears
Plums (fresh prunes)
Pecan
Peppers
Poultry, meat, fat, and meat
byproducts (inc. turkeys)
Pumpkins
Radishes
Rutabagas
Seed and pod vegetables
Sheep, fat
Sheep, meat and meat
byproducts
Soybean grain
Current
Tolerance
(ppm)
0.25
0.25
0.25
2.0
0.05
None
None
0.25
0.01
0.8
0.1
0.05
0.5
0.7
0.05
0.2
0.05
0.05
None
1.0
0.1
0.05
2
0.5
0.1
0.2
0.05
0.3
Tolerance
Reassessment*
(ppm)
0.25
0.25
0.25
2.0
0.05
1
0.2
0.25
Reassign
0.8
0.8
Revoke
Revoke
0.5
Revoke
0.05
0.2
0.05
0.05
0.2
1.0
0.1
0.1
0.1
0.05
2
0.5
Revoke
0.2
0.05
0.05
0.3
[Correct Commodity Definition]/
Comments
[Horse, fat]
[Horse, meaf|
[Horse, meat byproducts!

[ Vegetable, legume, group]
Recommended tolerance from PP#4F03 1 32.
Use previously covered under tree nuts.
[Milk fat (reflecting 0.01 ppm in -whole milk)]!
Recommended tolerance from PP#3F2884.
Covered by tolerance from milk fat (reflecting 0.01 ppm in
whole milk).
[Peppermint, tops]
[Spearmint, tops]
No registered uses exist.
[Nectarine]
[Onion, dry bulb)].
Not a feed item (Table 1, OPPTS 860.1000)
\Peach]
[Peanut, nutmeatj.

\Plums]
Use previously covered under tree nuts.
[Pepper] Chlorpyrifos labels from foreign countries that
import peppers to the U.S. are required.
\Poultryfat]
[Poultry, meat]
[Poultry, meat byproducts}
[Pumpkin]
\Radish]
[Rutabaga, root]
Uses of chlorpyrifos on dill and okra, for which this
obsolete crop group was supposed to cover, have been
deleted.

[Sheep, meat]
[Sheep, meat byproducts]
\Soybean, seed].
66

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Commodity
Soybean forage
Sorghum, fodder
Sorghum, forage
Sorghum, grain
Sorghum milling fractions
Strawberries
Sugarcane
Sunflower, seeds
Sweet potatoes
Tomatoes
Tree nuts
Turnip greens
Turnips
Vegetables, leafy, Brassica
(cole)
Walnuts
Wheat, forage
Wheat, grain
Wheat, hay
Wheat, straw
Current
Tolerance
(ppm)
0.7
6.0
1.5
0.75
1.5
0.2
0.01
0.25
0.05
0.5
0.2
0.3
1
2.0 (1.0) a
0.2
3
0.5
None
6
Tolerance
Reassessment*
(ppm)
Revoke
2.0
0.5
0.5
Revoke
0.2
Revoke
0.1
0.05
Revoke
Reassign
0.3
1
1.0
0.2
3
0.5
TBD
6
[Correct Commodity Definition}!
Comments
Feeding may be restricted on the label.
[Sorghum, grain, stover]. Recommended tolerance from
PP#4F3008/FAP#1H5295.
\Sorghum, grain, forage] .
\Sorghum, grain, grain].
According to Table 1, OPPTS Test Guidelines 860, August
1996, sorghum flour is used exclusively in the US as a
component for drywall, not as either a human or animal
feed item.
\Strawberry].
No registered uses exist.
[Sunflower, seed]. Recommended tolerance from
PP#4F3008/FAP#1H5295.
\Sweet potato, root].
The registrant has submitted a rebuttal to the modification
of this tolerance. This rebuttal is under review.
Individual tolerances exist for almond and walnut, and are
being established for filbert, pecan, and macadamia nut.
\Turnip, tops].
\Turnip, root].
[Vegetable, Brassica, leafy, group].
\Walnui\.




Tolerances Listed Under 40 CFR §180.342(a)(2)
Milling fractions (except
flour) of wheat
Mint oil
Peanut oil
1.5
8
0.4
Reassign
8
8
0.2
Wheat tolerance for wheat (0.5 ppm) will cover processed
milling fractions under the revised procedures for the
determination of need for food additive tolerances.
[Peppermint, oill
[Spearmint, oil]
[Peanut, refined oil]
Revised procedures for calculating food additive tolerance
values. (HAFT (O.ll)x average processing factor (1.7)).
Tolerances Listed Under 40 CFR §180.342(c)(l)
Asparagus
5.0
5.0

67

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Commodity
Dates
Grapes
Leeks
Current
Tolerance
(ppm)
0.5 (0.3) a
0.5
0.5 (0.2) a
Tolerance
Reassessment*
(ppm)
Revoke
0.01
Revoke
[Correct Commodity Definition]/
Comments
[Date] No registered uses exist.
[Grape] Tolerance based on currently registered US use
pattern. The registrant has submitted a rebuttal to the
modification of this tolerance. This rebuttal is under
review.
[Leek] No registered uses exist.
Tolerances Listed Under 40 CFR §180.342(c)(2)
Cherimoya
Feijoa (pineapple guava)
Sapote
0.05
0.05
0.05
Revoke
Revoke
Revoke
No registered uses exist.
No registered uses exist.
No registered uses exist.
* The term "reassessed" here is not meant to imply that the tolerance has been reassessed as required by FQPA, since this
tolerance may be reassessed only upon completion of the cumulative risk assessment of all organophosphates, as required by this
law. Rather, it provides a tolerance level for this single chemical, if no cumulative assessment was required, that is supported by
all of the submitted residue data.

       The Agency will commence proceedings to modify the existing tolerances, and correct
commodity definitions. The revocation of a tolerance, establishment of a new tolerance, or the
raising or lowering of tolerances will be deferred until submitted data are reviewed.

                     c. Codex Harmonization

       Residue data used to establish U.S. tolerances were examined to determine if U.S.
tolerance levels could be adjusted to harmonize with Codex Maximum Residue Limits (MRLs).
Whenever possible, tolerance levels were changed to achieve harmonization.

       Several maximum residue limits (MRLs) for chlorpyrifos have been established by
Codex in various commodities  as shown below in Table 30.  The Codex MRLs (expressed in
terms of chlorpyrifos per se) and the U.S. tolerance expression will be compatible when TCP is
deleted from the U.S. tolerance expressions.

       Compatibility between the U.S. tolerances and Codex MRLs exists for cabbage, Chinese;
kale [Brassica (cole) leafy vegetables group]; kiwifruits; milks; and poultry meat. Further
harmonization of U.S. tolerances and  Codex MRLs on other commodities are not feasible at this
time.  U.S. tolerances are based on domestic use patterns supported by domestic field trial data.
Codex MRLs may differ from U.S. tolerances because of different use patterns in foreign
countries.
                                             68

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                  Table 30.  Codex MRLs and Applicable U.S. Tolerances
Commodity
Apple
Cabbages, head
Carrot
Cattle meat
Cauliflower
Celery
Chicken meat
Chinese cabbage, type "Pe-tsai"
Citrus fruits
Common bean (pods and/or
immature seeds)
Cottonseed
Cotton seed oil, crude
Dried grapes
Eggplant
Eggs
Grapes
Kale
Kiwifruit
Lettuce, head
Milk
Mushrooms
Onion, bulb
Pear
Peppers
Potato
Raspberries, red, black
Rice
Sheep meat
Tomato
Turkey meat
MRL
(mg/kg) a
1
0.05 c
0.5
2 (fat)
0.05 c
0.05 c
0.1 (fat)
1
0.3
0.2
0.05 c
0.05 c
2
0.2
0.05 c
1
1
2
0.1
0.01 c
0.05 c
0.05 c
0.5
0.5
0.05 c
0.2
0.1
0.2 (fat)
0.5
0.2 (fat)
U.S. Tolerance
(ppm) b
0.01
1
None
0.05
1
None
0.1
1
1.0
0.05 (Legume vegetables group,
except soybeans)
0.2
None
0.5
None
0.01
0.01
1 (Brassica (cole) leafy
vegetables group)
2.0
1 (proposed)
0.01
Revoke
0.5
0.05
1.0
None
1.0 (caneberries)
None
0.05
Revoke
0.1 (poultry meat, including
turkeys)
Recommendation/
Comments
—
—
—
—
—
..
Compatibility exists.
Compatibility exists.
—
-
—
—
Recommend increase to 1.0.
—
—

Compatibility exists.
Compatibility exists.
—
Compatibility exists.
No registered US use.
—
—
—
—
—
—
..
under review
-
a  All chlorpyrifos MRLs are final (CXL).
b  Based on chlorpyrifos per se.
0  At or about the limit of detection.
                                             69

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              d. Endocrine Disrupter Effects

       EPA is required under the FFDCA, as amended by FQPA, to develop a screening
program to determine whether certain substances (including all pesticide active and other
ingredients) "may have an effect in humans that is similar to an effect produced by a naturally
occurring estrogen, or other such endocrine effects as the Administrator may designate."
Following the recommendations of its Endocrine Disrupter Screening and Testing Advisory
Committee (EDSTAC), EPA determined that there were scientific bases for including, as part of
the program, the androgen and thyroid hormone systems, in addition to the estrogen hormone
system. EPA also adopted EDSTAC's recommendation that the Program include evaluations of
potential effects in wildlife.  For pesticide chemicals, EPA will use FIFRA and, to the extent that
effects in wildlife may help  determine whether a substance may have an effect in humans,
FFDCA authority to require the wildlife evaluations.  As the science develops and resources
allow, screening of additional hormone systems may be added to the Endocrine Disrupter
Screening Program (EDSP).

       When the appropriate screening and/or testing protocols being considered under the
Agency's EDSP have been developed, chlorpyrifos may be subjected to additional screening
and/or testing to better characterize effects related to endocrine disruption.

                    e. Labels

       Provided the following risk mitigation measures are incorporated in their entirety into
labels for chlorpyrifos-containing products, the Agency finds that, with the exception of the dust
formulation for fire ant control, all currently registered uses of chlorpyrifos are eligible for
reregi strati on, pending consideration of cumulative risks of the organophosphates. The
regulatory rationale for each of the mitigation measures outlined below is discussed immediately
after this list of mitigation measures.

Dietary Risk

       Neither acute nor chronic dietary (food and drinking water) risks are of concern.  This
conclusion  reflects measures agreed to in the Memorandum of Agreement of June 2000
eliminating use on tomatoes and limiting use on grapes and apples.  No further mitigation is
necessary at this time.

Occupational Risk

       In order for chlorpyrifos products (except for the dust formulation for fire ant control) to
be eligible for reregi strati on, a combination of reduced application rates and seasonal maximum
limits, increased retreatment intervals, increased PPE and/or use of engineering controls to
address occupational handler risks are needed. In addition, increased REIs for a number of crops
will address postapplication risks to workers. Taking into account all feasible mitigation, several
worker scenarios are still below the target MOE of 100.  In such cases,  and in accordance with

                                           70

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PR Notice 2000-9, EPA further characterizes the risk by looking at the strengths and weaknesses
of the data and assumptions used in the risk assessment and evaluates the benefits of a
chemical's use. The worker scenarios are discussed further below.

Residential Risk

       No mitigation is necessary at this time.  All products for homeowner use except ant and
roach baits in child-resistant packaging have been canceled. Professional termiticide treatment
products are being phased out, with all use for termite control prohibited by December 31, 2005.

Ecological Risk

       Risks to terrestrial and aquatic organisms are of concern for all outdoor uses of
chlorpyrifos. To address these risks, reductions in application rates, the number of applications
per season and the maximum amount that may be applied per acre per season and increased
intervals between applications will be needed. In addition, no-spray buffer zones will be applied
to protect water bodies, further mitigating aquatic risks. Taking into account mitigation, some
aquatic risk quotients still exceed levels of concern, particularly for estuarine invertebrates.  EPA
has considered benefits of chlorpyrifos use on the major crops contributing to aquatic risk
concerns. The Agency will also require submission of water monitoring data to confirm the
reduction of chlorpyrifos levels in surface water.
       C. Regulatory Rationale

       The following is a summary of the rationale for managing risks associated with the
current use of chlorpyrifos products. Where labeling revisions are warranted, specific language
is set forth in the summary tables of Section V of this document.

              1. Benefits

       The Agency has considered the benefits of chlorpyrifos use in its determination of
eligibility for reregi strati on as well as appropriate reduction of remaining risks.  Since corn,
cotton, citrus and alfalfa represent approximately 70% - 80% of the use of chlorpyrifos and thus
are the greatest contributors to ecological risk, the  Agency has considered the benefits of
chlorpyrifos use on these sites.

Corn

       Chlorpyrifos use on corn (an estimated 5 /^ to 7 million pounds) accounts for more than
half of the total annual use of chlorpyrifos in agriculture. Chlorpyrifos is applied to corn
primarily to control corn rootworm (larvae and adults), cutworm and European corn borer. Corn
growers considered chlorpyrifos critical for control of these damaging pests. The granular
product is primarily incorporated in the soil at the time corn is planted for control of rootworm

                                           71

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larvae. This type of application represents the largest use of chlorpyrifos with approximately 4
to 5 V2 million pounds applied annually.  Granular applications have the additional benefit of
protecting the corn from cutworm.  Foliar applications of granular chlorpyrifos by air are
targeted at European corn borer.  This method represents a relatively small portion of
chlorpyrifos use-approximately 100,000 pounds of active ingredient per year. Approximately
500,000 pounds of the liquid formulation of chlorpyrifos are applied to corn per year.  The liquid
formulation is generally used as a foliar application, with some at-plant use as well.

       The principal alternatives to chlorpyrifos on corn are terbufos (which is currently
undergoing reregistration), tefluthrin, fipronil, and a combination product of tebupirimphos and
cyfluthrin.  The most effective non-chemical alternative for management of corn rootworm is
crop rotation, which is practiced on the majority of corn acreage.

Citrus

       Approximately 600,000 pounds of chlorpyrifos are applied annually to citrus primarily in
California and to a lesser extent in Florida. Chlorpyrifos is the most effective product available
for the control of California red scale (CRS). Other insecticides used to control CRS include
methidathion, carbaryl, and oil.  Chlorpyrifos is preferred due to its effectiveness against CRS
and its relatively short residual activity compared to the other available insecticides.
Chlorpyrifos' short residual minimizes the impact on beneficial insects such as theAphytis wasp,
which is important for late season biological  control of CRS populations. The majority of
California citrus is grown for the fresh market and for export. Although CRS damage  is
primarily cosmetic, there is a low threshold for CRS damaged fruit in these markets.

       In Florida, Chlorpyrifos is used as an alternative chemical control for managing scale and
thrips, and it is used to manage nuisance pests such as fire ants and termites in the grove. The
majority of the chlorpyrifos use in Florida is  for the control of fire ants.  There are currently no
alternatives labeled for this use. Fire ant control is critical to allow workers the opportunity to
complete orchard production activities, such  as harvesting, without the threat of attack by the fire
ants.

Cotton

       Approximately 700,000 pounds of chlorpyrifos are applied annually to cotton.  Liquid
chlorpyrifos is used on cotton primarily to control plant bugs in the Mississippi delta area, cotton
aphid in Texas and California, silverleaf whitefly in Arizona, pink bollworm in Arizona and beet
armyworms in all cotton growing areas.  It is considered to be important in resistance
management programs for cotton aphid.  Alternatives to chlorpyrifos for aphid control include
profenofos and carbofuran. Imidacloprid provides early  season aphid and plant bug control.
Two relatively new insect growth regulators (IGR), pyriproxyfen and buprofizen, have shown
good control of silverleaf whitefly.
                                            72

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Alfalfa

       Approximately 500,000 Ibs. ai of chlorpyrifos are applied annually to alfalfa by both
ground (Midwest to Northeast) and air (West) equipment. A single application per year is
typical.  Alfalfa weevil, Egyptian alfalfa weevil, army worms (beet and Western yellowstriped)
and aphids are the key pests. The principal alternatives to chlorpyrifos are carbofuran, methyl
parathion and dimethoate.  Pyrethroids are also registered for alfalfa pest management, but do
not suppress and control aphids, as well as chlorpyrifos, carbofuran and methyl parathion.
       Since corn, cotton, citrus and alfalfa represent 70% - 80% of the chlorpyrifos use, the
Agency has considered the benefits of chlorpyrifos use on these sites. Additional benefits
information on these and other uses can be found in the public docket and is discussed under
specific worker scenarios below in the Occupational Risk Mitigation section.  Usage information
can also be found at http://pestdata.ncsu.edu/cropprofiles/cropprofiles.cfm.

             2. Human Health Risk Mitigation

                    a. Dietary Mitigation

                           1) Acute Dietary (Food)

       Based on use patterns established before the June 2000 mitigation agreement, acute
dietary risk from food alone at the 99.9th percentile for the most highly exposed subpopulation,
children 1-6  years old was 355% of the aPAD. The mitigation agreement addressed this risk by
reducing or canceling use on three commodities frequently consumed by children: apples, grapes
and tomatoes. Post-bloom use on apples was removed from product labels effective December
31, 2000 and the tolerance will lowered to 0.01 ppm.  Production  of products for use on tomatoes
was prohibited effective September 2000, and use of existing products was stopped as  of
December 31, 2000. The tolerances for tomatoes will be revoked. The tolerance for grapes will
be lowered to 0.01 ppm to reflect domestic use patterns.  The Agency is coordinating with the
FDA to implement these tolerance reductions/revocations.  The registrant has submitted a
rebuttal to the modification of the tolerances.  This rebuttal is under review.

       With implementation of these reductions, acute dietary risk from food alone is at 82% of
the aPAD for children 1-6 years old, and thus is not of concern. No further mitigation  of acute
dietary risk is needed at this time.

                           2) Chronic Dietary (Food)

       Prior to implementation of the mitigation for apples, grapes and tomatoes, chronic dietary
risk from food alone occupied 81% of the cPAD for children 1-6 years old, the most highly
exposed population subgroup, and thus was not of concern.  The mitigation further reduced risks

                                           73

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to a range of 2.5% to 51% of the cPAD. No additional mitigation of chronic dietary risk is
needed at this time.

                           3) Drinking Water

       Neither acute nor chronic risks from drinking water are of concern for any population
subgroup, except in the event of well contamination following termiticide use. Incidents of these
types have occurred in the past as a result of the high concentrations required for termiticide use,
treatments being applied when wells were in or near the building foundation, and/or when well
casings were cracked. Since issuance of PR 96-7 instituting risk reduction measures for
termiticides, the number of reported incidents has dropped significantly.  For example, the
frequency of incidents in 1997 (before PR 96-7) was 28.2 per 100,000 homes; in 1998 (after the
notice) the frequency was 8.3 per 100,000 homes.

       To address these remaining risks, termiticide products were reclassified to "restricted
use." In addition, the application rate for all termiticide products was limited to 0.5% solution
effective December  1, 2000. Use and sale of termiticide products will be phased out as follows:
formulation of products for post-construction treatment stopped on December 1, 2000, and all
sales of whole-house and spot/local treatment products will stop effective December 31, 2001,
and December 31, 2002, respectively. Production of products for pre-construction treatment will
stop as of December 31, 2004; these products  may not be used after December 31, 2005. A
provision of the June 2000 agreement allows the technical registrants to submit exposure data by
June 2004. If acceptable data  demonstrate that pre-construction use does not pose risks of
concern to residents, that use may be allowed to continue.

                    b. Occupational Risk Mitigation

                           1) Agricultural and Ornamental/Greenhouse Handler Risks

       Since the chlorpyrifos  occupational assessment was completed, some refinements in
methodology have been identified. In calculating occupational handler risks for the preliminary
Human Health Risk Assessment completed in June 2000, the potential dermal and inhalation
doses used to calculate exposures were those identified in the Agency's Series 875 Group A
(previously known as Subdivision U).

       However, for dermal calculations, the ratio of the body surface area to the body weight
has been found to overestimate risk by a factor of 1.1.  The ratio is not physiological matched in
that the surface area is for an average male, while the body weight is the median for both male
and female.  Therefore, dermal MOEs from the June 2000 assessment have been adjusted with a
reduction factor of 1.1 and are presented in the following table.

       In addition, to calculate inhalation risks for handlers, the Agency used a standard
breathing rate of 29 L/min for all exposure scenarios.  Since that time, the Agency has adopted
the breathing rates recommended by NAFTA. The NAFTA inhalation rates and the

                                          74

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corresponding exposure reduction factors are:  8.3 L/min. for sedentary activities (e.g., driving a
tractor); exposure reduction factor 3.5;  16.7 L/min. for light activities (e.g., flaggers and
mixer/loaders using <50 Ib. containers); exposure reduction factor 1.7; and 26.7 L/min. for
moderate activities (e.g., loading >50 Ib. containers or using handheld equipment in hilly areas);
exposure reduction factor 1.1.

       Table 31 presents the MOEs for occupational risk taking into account the revised dermal
surface area and breathing rate factors.
                                             75

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Table 31.  Occupational Risk Estimates for Agricultural Uses of Chlorpyrifos
Exposure Scenario
(Scenario#)
Application Rates
(Ib ai/acre)
Daily Acres
Treated
Short-Term PPE MOEs
Dermal
Inhalation
Total
Short-Term Eng. Control MOEs
Dermal
Inhalation
Total
Mixer/Loader Exposure
Mixing/Loading Liquids
for Aerial/Chemigation
Application (la)
Mixing/Loading Liquids
for Groundboom
Application (Ib)
Mixing/Loading Liquids
for Airblast Application
(Ic)
Mixing WP for
Aerial/Chemigation
Application (2a)
Mixing WP for
Groundboom Application
(2b)
Mixing WP for Airblast
Application (2c)
Loading Granulars for
Aerial Application (3a)
1.5 cranberries, corn
3.5 citrus
1.5 predominant max
2 Sodfarm
(includes tobacco/
potatoes)
3 Sodfarm
8.0 sodfarm fire ants
2.0 predominant max
such as Fruits &
Nuts
6.0 citrus
2.0 predominant max
(orchards)
3.5 citrus (d)
1.0 predominant max
(brassica)
4.0 soil treatment
ornamentals outdoors
1.3 & 3.0 Sodfarm
8.0 sodfarm fire ants
(harvest only)
2.0 predominant max
6.0 citrus
1.0 maximum aerial
rate for corn
350
100
80
80
80
10
40
20
350
100
80
10
80
10
40
20
350
43
65
187
143
88
286
286
187
95
141
408
306
193
612
612
408
30
44
128
97
60
195
195
128
DAS is not supporting the open bag formulation for the
WP
321
99
75
86
132
272
408
66
100
Target MOE reached at PPE
275
278
901
861
211
210
Target MOE reached at PPE
Target MOE reached at PPE
Target MOE reached at PPE
56
110
495
979
374/165
495
495
330
3300
71
141
612
1241
476 / 204
360
612
408
510
31
62
274
547
209 / 91
200
274
182
442
                                  76

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Exposure Scenario
(Scenarios)
Loading Granulars for
Ground Application (3b)
Application Rates
(Ib ai/acre)
1.0 typical corn
2.0 max corn
3.0 maximum ground
rate (tobacco)
Daily Acres
Treated
80
80
80
Short-Term PPE MOEs
Dermal
1430
704
473
Inhalation
442
221
146
Total
338
168
112
Short-Term Eng. Control MOEs
Dermal
Inhalation
Total
Target MOE reached at PPE
Target MOE reached at PPE
Target MOE reached at PPE
Applicator Exposure
Aerial (Spray) ~ Enclosed
Cockpit (4a)
Aerial (Granulars) ~
Enclosed Cockpit (4b)
Groundboom Tractor (5)
Airblast Applicator (6)
Tractor-Drawn Granular
Spreader (7)
Seed Treatment (8)
Dip Application (Preplan!
Peaches) (9_) 	
2.0 orchards
3.5 citrus
1.0
1.5 predominant max
3 Sodfarms
8.0 sodfarm fire ants
2.0 predominant max
6.0 citrus
1.0 typical corn
2.0 max corn
3.0 maximum ground
rate (tobacco)
No Data
No Data
350
100
350
80
80
10
40
20
80
80
80
No Data
No Data
No Open cockpit data available
No Open cockpit data available
The biological monitoring results (Table A4) indicate
that open cabs provide insufficient protection.
Therefore, only the enclosed cab MOEs are presented.
The biological monitoring results indicate that open
cabs are insufficient.
1100
572
385
1260
630
420
587
300
201
No Data
No Data
110
220
686
638
302
968
253
165
525
1015
55
4900
2231
7000
665
455
91
181
51
564
270
850
183
121
Target MOE reached at PPE
Target MOE reached at PPE
Target MOE reached at PPE
No Data
No Data
Flagger Exposure
Spray Applications (10)
Granular Applications (11)
2.0 predominant max
3.5 citrus (d)
1.95
350
100
350
55
110
352
490
319
374
49
82
181
2530
4950
1540
3190
957
1940
Target MOE reached at PPE
Mixer/Loader/Applicator Exposure
77

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Exposure Scenario
(Scenario#)
Backpack Sprayer/Bark
and Pine Seedling
Treatment (12)
Low Pressure Handwand
(13)
High Pressure Handwand
(greenhouse uses) (14)
Hydraulic Hand-held
Sprayer for Bark Treatment
(15)
Application Rates
(Ib ai/acre)
0.0417 Ib ai/gal
predominant max
0.08 Ib ai/gal bark
beetle treatment
0.03 Ib ai/gal stump
treatment
0.16 Ib ai/gal pine
seedling treatment
3.5 citrus bark
0.039 Ib ai/gal /750
ft2
0.0417 Ib ai/gal
predominant max
0.08 Ib ai/gal bark
beetle treatment
0.03 Ib ai/gal stump
treatment
3.5 citrus bark
0.039 Ib ai/gal/
750 ft2 animal prem.
Min. 0.0033 Ib ai/gal
Max. 0.0066 Ib ai/gal
3.5 citrus bark
0.08 Ib ai/gal bark
beetle treatment
0.039 Ib ai/gal /750
ft2 animal prem
Daily Acres
Treated
40 gal/ day
40 gal/day
40 gal/day
40 gal/ day
1 A/day
1000 ft2
40 gal/day
40 gal/day
40 gal/day
1 A/day
1000 ft2
1000 gal/day

10
1,000 gal/day
10000 ft2
Short-Term PPE MOEs
Dermal
143
75
198
37
69
4620
627
330
869
297
19,800
73
36
18
15
2420
Inhalation
770
396
1067
198
363
24,200
770
396
1067
363
24,200
97
48
110
97
14,300
Total
121
63
167
31
58
3,879
346
180
479
163
10,890
41
21
15
13
2070
Short-Term Eng. Control MOEs
Dermal Inhalation Total
Target MOE reached at PPE,
Not feasible
Target MOE reached at PPE,
Not feasible
Not feasible
Target MOE reached at PPE
Target MOE reached at PPE
Target MOE reached at PPE
Target MOE reached at PPE
Target MOE reached at PPE
Target MOE reached at PPE
Not feasible
Not feasible
Not feasible
Not Feasible
Target MOE reached at PPE
78

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Exposure Scenario
(Scenarios)
Dry Bulk Fertilizer
Impregnation
Application Rates
(Ib ai/acre)
1.01bai/2001b
fertilizer / acre
Daily Acres
Treated
No Data
Short-Term PPE MOEs
Dermal Inhalation
Total
No Data
Short-Term Eng. Control MOEs
Dermal Inhalation
No Data
Total

79

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       The following scenarios are not of concern, i.e., MOEs are greater than 100, with PPE
consisting of double layers, chemical resistant gloves, chemical resistant shoes plus socks,
chemical resistant headgear for overhead exposure, chemical resistant apron when cleaning and
mixing or loading and a dust/mist respirator:

(Ib)   Mixing/loading liquids for groundboom application (except at 3 Ibs. ai/A sodfarm use)
(Ic)   Mixing/loading liquids for airblast application
(3b)   Loading granulars for ground application
(7)    Tractor drawn granular spreader
(13)   Low pressure handwand

The following scenarios have MOEs greater than 100 with appropriate engineering controls:

(2b)   Mixing wettable powder for groundboom application (water soluble packaging)
(2c)   Mixing wettable powder for airblast application (water soluble packaging)
(4a)   Aerial application of spray (enclosed cockpit)

       The following occupational risk scenarios are still below the target MOE of 100, even
with all feasible PPE or engineering controls.

Mixing/Loading Liquids for Aerial/Chemigation Application

       The MOEs for mixing/loading liquids for aerial application (scenario la) are 66 and 100
depending on the application rate and the acres treated. The dermal route is  driving the total
MOE in this scenario (dermal MOEs range from 86 to 132 and the inhalation MOEs range from
272 to 408). Mixer/loaders for aerial application must use mechanical transfer systems for any
container greater than 2.5 gallons for transfer of material from container to chemical holding
tank. The registrant has agreed to reduce the rate on corn from 1.5 to 1 Ib ai/A.

       Aerial application is critical to large field crops such as cotton, wheat and sorghum.
Ground application is not economically feasible. Approximately 200,000 Ibs. ai of chlorpyrifos
are applied per year to sorghum for control of greenbugs.  Chlorpyrifos is the primary insecticide
for foliar applications to wheat and is important for control of Russian wheat aphid, pale western
cutworm and grasshoppers. Approximately 100,000-150,000 Ibs ai per year are applied to wheat.

       For chemigation the MOEs will be higher than aerial application because the typical use
rates are lower (0.5 to 1 Ib ai/A) and the acres treated would typically average 40 to 80 acres.
The combination of these lower rates and acres will increase the MOEs above 100.
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Mixing/Loading Liquids for Groundboom Application to Sodfarms at 3 Ibs. ai/A

       The MOE for mixing/loading liquids for groundboom application to sodfarms at the 3
Ibs. ai/A rate (scenario Ib) is 60.  Currently enclosed mixing/loading is not required for the
groundboom application to sodfarms.  Dermal exposure contributes the most to the total MOE in
this scenario (dermal MOE is 88 and the inhalation MOE is 193). The 3 Ib. ai/A rate is used to
control mole crickets and is mainly used as  a patch application. Therefore, the 80 acres applied
in a day is an overestimate for this particular use.  The 2 Ibs. ai/A rate is critical for the control of
chinch bugs and lepidopterus (sod webworms, cutworms and army worms). Current PPE
consists of double-layer clothing, chemical  resistant gloves, chemical resistant shoes plus socks,
chemical resistant headgear for overhead exposure, chemical  resistant apron when cleaning and
mixing or loading and a dust/mist respirator. Usage data are being required to confirm the acres
treated per day for the 3 Ibs. ai/A rate on sodfarms to control mole crickets,  and will be used to
refine risk estimates.

Mixing Wettable Powders for Aerial/Chemigation Application

       The MOEs for mixing wettable powders in water soluble packaging (WSP) for aerial or
chemigation application (scenario 2a) are 31 and 62, depending on the application rate the
worker uses and the acres treated.  EPA acknowledges the uncertainties associated with the risk
assessment for WSP for aerial or chemigation application. Current WSP data in PHED are of
low quality due to a limited number of replicates.

       EPA believes the actual exposure from water soluble packaging in aerial/chemigation
operations is less than predicted by the limited data in PHED.  Confirmatory data will be
required for the WSP formulation. These data may be developed in conjunction with the
Agricultural Handler Task Force which has been formed between EPA and the industry to
generate data to update PHED.

Loading Granulars for Aerial Application

       The MOE for loading granulars for aerial application is 75 (scenario 3a). The inhalation
route is driving the total MOE in this scenario (dermal MOE is 321 and the inhalation MOE is
99).  Currently enclosed loading systems are not required for loading chlorpyrifos granulars for
aerial application.

       Because of new technology to reduce the dust and exposure from granular pesticides,
EPA believes the actual exposure from loading granulars for aerial application is less than
predicted by the limited data  in PHED. Confirmatory data will be required for loading granulars.
These data may be developed in conjunction with the Agricultural Handler Task Force which has
been formed between EPA and the registrants to generate data to update PHED.
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Aerially Applying Granulars

       The MOE for aerially applying granulars is 51 (scenario 4b).  The inhalation route is
driving the total MOE in this scenario (dermal MOE is 686 and the inhalation MOE is 51). The
inhalation data in PHED for this scenario is of low confidence because it lacks the sufficient
replicates. The data in PHED for applying granulars is based on smaller acreage being treated.
The pilot entered and left the plane after every 17-acre application. For  chlorpyrifos where up to
350 acres are treated per day this would result in an overestimate because the pilot would not be
entering and leaving the plane after every 17 acres. Information  from aerial applicators indicate
that entering and leaving the plane 3-4 times during the day is typical

       EPA believes the actual exposure from applying granulars for aerial application is less
than predicted by the limited data in PHED.  Confirmatory data will be required for applying
granulars. These data may be developed in conjunction with the Agricultural Handler Task
Force which has  been formed between EPA and the registrants to generate data to update PHED.

Airblast/Groundboom Application

       The MOEs for airblast/groundboom application range from 121 to 850 depending on the
application rate and acres treated and with the engineering control of an  enclosed cab  (scenario 5
and 6). A label statement is needed indicating that airblast applicators must wear double-layer
clothing and a dust-mist respirator.

       The available biological monitoring data for groundboom application was conducted with
baseline PPE (one-layer of clothing) and are of minimal quality due to a low number of
replicates. A label  statement is needed indicating that groundboom applicators must wear
double-layer clothing.

       Confirmatory data will be required for groundboom application.  These data may be
developed in conjunction with the Agricultural Handler Task Force which has been formed
between EPA and the registrants to generate data to update PHED.

Backpack Sprayer

       Risks to mixer/loader/applicators using a backpack sprayer for bark beetle and pine
seedling treatment (scenario 12) are of concern. For bark beetle  treatment using 3.5 Ibs. ai/A
(for citrus bark),  the MOE is 58; for other crops at 0.08 Ibs. ai/gal, the MOE is 63; and for pine
seedling treatment, the MOE is 31. These risk estimates are of low confidence because the data
available lacked  sufficient replicates to meet Agency guideline requirements.

       Dermal exposure contributes most to the total MOE in this scenario. Dermal MOEs
range from 37 to 75 while the inhalation MOEs range from 198 to 396.  Confirmatory backpack
exposure data are required and are being developed by the Forest Service (USDA) to refine
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current risk estimates. The Agency has reviewed the study protocol and the study will be
initiated in Spring of 2002.

       The Forest Service has stated that chlorpyrifos is important in the control of bark beetles
or borers and that no suitable alternative exists. Documentation from the Forest Service
indicates that 40 gallons per day (as assumed in EPA's assessment) would rarely if ever be used
for pine seedlings.

       Since the Human Health Risk Assessment was conducted, product labels for this use were
amended to add protection including double layers, chemical-resistant gloves, footwear and
apron (for mixers and loaders). These protective measures will be required unless or until
exposure data for this scenario are submitted and demonstrate otherwise.

High Pressure Handwand

       Mixer/loader/applicator risks for use of the high-pressure handwand (scenario 14) are of
concern, with MOEs of 41 and 21 depending on the application rate. These risk estimates are
based on biological monitoring data but are of low confidence due to a lack of information on the
types of sprayers and volumes used in the studies. In addition, the data lacked sufficient
replicates to meet Agency guideline requirements.  Comments from the American Nursery and
Landscape Association indicate the EPA's assumption of 1,000 gallons per day of use are
extremely unrealistic. Chlorpyrifos is used as a rotational tool to treat small blocks or areas of
plant material-only to areas of the greenhouse that have infestation problems. Actual use is
likely to be 100 gallons per day or less, and use is intermittent. Usage data are being required to
confirm the current use per day.  Additional information is required concerning the types of
sprayers used. This information will be used to refine risk estimates.

       Since the Human Health Risk Assessment was conducted, product labels for this use were
amended to add protection including double layers, chemical-resistant gloves, footwear and
apron (for mixers and loaders). These protective measures will be maintained unless or until
exposure data for this scenario are submitted and demonstrate otherwise.

Hydraulic Handheld Sprayer

       Risks to mixer/loader/applicators using a hydraulic handheld sprayer (scenario 15) are of
concern.  For application to citrus bark at 3.5 Ibs./gal, the MOE is 15; for other  crops at 0.08
Ibs./gal, the MOE is 13.  These risk estimates are of low confidence because the data lacked
sufficient replicates.  The driving factor in this assessment is the volume of spray estimated to be
applied. Usage data are  being required to confirm the actual amount of chlorpyrifos used on a
daily and seasonal basis.  Preliminary industry estimates report a high end usage of about 500
gallons a day, half of EPA's estimate assumed. Additional information is required concerning
the types of sprayers used since EPA's assessment assumed a rights-of-way type sprayer. This
information will be used to refine risk estimates. The Forest Service has stated  that chlorpyrifos
is important in the control of bark beetles or borers and that no suitable alternative exists.

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       Since the Human Health Risk Assessment was conducted, product labels for this use were
amended to add protection including double layers, chemical-resistant gloves, footwear and
apron (for mixers and loaders). A dust-mist respirator will also be necessary.

Dry Bulk Fertilizer Impregnation

       Risks to mixer/loader/applicators for dry bulk fertilizer impregnation could not be
assessed due to a lack of exposure data. This use is for the control of fire ants on orchard floors.
For this use, dry fertilizer is placed in a closed rotary drum mixer equipped with suitable
spraying equipment.  Spray nozzles are positioned to provide uniform spray coverage of the
tumbling fertilizer with chlorpyrifos.

       This use is similar to mixing/loading liquids for groundboom application at the 1 pound
rate (scenario Ib) and applying with a tractor drawn granular spreader (scenario 7). The MOEs
are above 100 for both of these scenarios. Thus, EPA assumes that PPE for this use should be
similar, i.e., double-layer clothing.

Seed Treatment

       The Agency has  no data at this time to assess the exposure for mixer/loaders and
applicators for seed treatment. Seed treatment labels currently specify single-layer clothing,
chemical-resistant footwear over socks, chemical-resistant gloves and respirators.  The Agency
does not anticipate that the exposures for this use with the prescribed PPE will be any greater
than for mixer/loaders of wettable powders for groundboom application with engineering
controls (MOEs 200-400), and the amount of ai handled per day is likely to be less. Therefore,
this use is eligible for reregi strati on and confirmatory data are required.  This protective
equipment must be maintained on the labels until/unless exposure data indicate that less PPE is
appropriate.

Preplant Peach Dip

       The Agency has  no specific data at this time to assess the exposure for mixer/loaders and
applicators for the preplant peach dip.  Labels for the preplant peach dip currently require
double-layer clothing, chemical-resistant gloves, chemical-resistant shoes plus socks, protective
eyewear, chemical-resistant headgear for overhead exposure, chemical-resistant apron when
cleaning equipment and  mixing or loading and a respirator.  The Agency does not anticipate that
exposures for this use will be  any greater than for mixer/loaders of liquids for citrus and fruit
ground applications (MOEs 100-150) and the amount of ai handled per day is likely to be less.
Confirmatory data are required.  Therefore, this use is eligible for reregi strati on and
confirmatory data are required.  This protective equipment must be maintained on the label
until/unless exposure data indicate that less PPE is appropriate.
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Flaggers

       Risks to flaggers involved in spray applications (scenarios 10 and 11) are of concern with
use of PPE, with MOEs of 49 and 82. Information from USDA indicates that human flagging is
no longer necessary in modern agriculture. Therefore, a prohibition against human flagging will
mitigate these risks with minimum impact on current production practices.

       Taking into account the strengths and weaknesses of the risk assessment and the benefits
of chlorpyrifos use, EPA has determined that the uses listed above are eligible for reregi strati on
with the designated mitigation and confirmatory data.
                           2) Agricultural and Ornamental/Greenhouse Postapplication
Risks
       The results of the short- and intermediate-term postapplication assessments indicate that
REIs need to be established.  The REIs range from 24 hours for most crops to 5 days for citrus
trees.  REIs and pre-harvest intervals (PHIs) are needed to ensure that risks are not of concern
are shown below in Table 32.

              Table 32. Restricted Entry Intervals  and Preharvest Intervals
Crop
Cauliflower
Nut trees
Potatoes
Citrus trees
Fruit trees
Sweet corn
All other crops
REI
3 days
24 hours
24 hours
5 days
4 days
24 hours
24 hours
MOEs
150
270
750
220
280
83
110
PHI
21-30 days
14 days
7 days
21 days
21 days
7 days
7 days
       In addition to the foliar chlorpyrifos treatments, there are many soil incorporated/directed
treatments to field crops and citrus. At this time, there are insufficient exposure and soil residue
data to assess the potential risk from soil incorporated/directed uses of chlorpyrifos. However,
these treatments are expected to result in less postapplication exposure than the foliar treatments.
Confirmatory data for soil directed/incorporated uses are required.

       Postapplication risks to greenhouse/nursery workers were not assessed due to a lack of
data. Information is needed concerning the timing of the applications in relation to the
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postapplication activities and a lack of residue data (foliar and bark treatments) to assess the
REIs for the ornamental/greenhouse uses. These risks are of concern for activities such as
pruning, transplanting and burlap/balling. The National Agricultural Pesticide Impact
Assessment Program (NAPIAP 1996) reports chlorpyrifos is widely used for a broad range of
insect applications including wood-boring, foliage feeding, sucking and soil-borne pests.
NAPIAP also reports that although chlorpyrifos use represents only 5% of the total Ibs. ai used
in greenhouse/nursery operations, it is used by 35% of their survey respondents.  Chlorpyrifos is
an important chemical for the industry, especially as a tool for resistance management.
Additional use information, i.e., timing of application relative to postapplication activities,
greenhouse DFR data, and biological monitoring data to develop transfer coefficients for various
greenhouse/nursery activities are required.

       The current REI of 24 hours was  established by the MOA of June 2000 and remains in
effect until acceptable data indicate that it should be changed.
                           3) Non-Agricultural Occupational Handler Risks

       Risk estimates for the application of a dust product for fire ant control are of concern.
With PPE, the short-term MOEs are 4.3 to 108; intermediate-term MOEs are 0.9 to 22.  These
MOEs are based on one literature study, which did not include inhalation exposure data;
therefore, the MOEs are likely to underestimate actual risk.  This use is ineligible for
reregi strati on at this time.  Since this product is used to control fire ants and may have public
health benefits, registrants and other interested parties may provide benefits and usage
information and mitigation suggestions during the comment period.

       Application by groundboom to golf course turf is of concern. Using baseline PPE, the
short-term MOE is 60. A label statement is needed indicating that groundboom applicators must
be in fully enclosed cabs or, if not in fully enclosed cabs, applicators must wear double-layer
clothing, chemical-resistant footwear and socks, and a dust-mist respirator.
                            4) Non-Agricultural Occupational Postapplication Risks

       Occupational postapplication exposures by commercial operators in the residential
setting (termiticide and mosquito adulticide uses) are not expected to occur. For golf course
workers, postapplication exposures are not of concern.
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                     c. Residential Risk Mitigation

                           1) Residential Handler Risk

       The only products that can be applied by a resident are the containerized baits in child-
resistant packaging. This is not expected to result in exposures of concern.  All other residential
uses have been canceled.

                           2) Residential Postapplication Risk

       Residential postapplication exposures may occur after termiticide use in residential
structures. To mitigate risks from this use, the technical registrants agreed in June 2000 to limit
termiticide treatments to 0.5% solution, and cancel all postconstruction uses. Pre-construction
use will remain until 2005, unless acceptable exposure data are submitted that show that
residential postapplication risks from this use are not a concern.

       Chlorpyrifos treatments to processed wood products was maintained in the Memorandum
of Agreement of June, 2000. Since that time, it has  come to the Agency's attention that some
wood products such as window frames and floor joists that are treated are eventually used in
homes.  Exposure data are required to confirm that this use is not a concern.

              3. Environmental Risk Mitigation

       The technical registrants have agreed to the following label amendments to address
environmental risk concerns. The amendments include the use of buffer zones to protect water
quality, fish and wildlife, reductions in application rates, number of applications per season,
seasonal maximum amounts applied, and increases in the minimum intervals for retreatment.

       The mitigation measures prescribed in this IRED along with mitigation that is already
being implemented as a result of the June, 2000, Memorandum of Agreement, will reduce risk to
both terrestrial and aquatic species. For example, many of the reported incidents of wildlife
mortality associated with chlorpyrifos use were related to residential lawn and termite uses  and
use on golf courses. The residential uses have been eliminated, the termiticide use is being
phased out, and the application rate on golf courses  has been reduced from 4 to 1  Ib/ai/A.
Additionally, no-spray buffers around surface water bodies, as well as rate reductions for
agricultural uses will be implemented as a result of this IRED and will further reduce the
environmental burden of chlorpyrifos.

       Although the magnitude of the risk reduction cannot be precisely quantified, EPA's
recalculation of risk quotients, taking into account new use restrictions, indicates that the
potential risk to invertebrates, particularly estuarine invertebrates may still be of concern. Risk
quotients represent a screening level assessment and are inadequate to predict whether the levels
of chlorpyrifos entering estuarine areas are sufficient to affect invertebrate populations or

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populations of the larger species that depend on them as a food source. Monitoring for
chlorpyrifos in waters that feed into estuaries would provide useful information on the
magnitude and frequency of actual residues.

       Taking into account the extensive mitigation already underway, additional mitigation to
be adopted as a result of this IRED, as well as the benefits of chlorpyrifos use, EPA finds the
remaining risk to non-target species is not unreasonable.  Because the use of chlorpyrifos will be
declining over the next few years as existing stocks of canceled products are exhausted, EPA
expects that levels of chlorpyrifos in the environment will also be reduced.  In order to confirm
that levels of chlorpyrifos in the aquatic environment are declining, EPA is requiring updated
usage information and collection of water monitoring data for the areas of greatest remaining
chlorpyrifos use.

       The following crop-specific mitigation will be needed to address environmental risk
concerns:

Alfalfa (liquid formulations)

       The maximum number of applications per season will  be reduced from 8 to 4.

Citrus (liquid formulations)

       The maximum number of applications per season will  be limited to 2; the maximum
application rate of 6 Ibs. ai/A will be limited to five counties in California (Fresno, Tulare, Kern,
Kings, and Madera); the minimum interval for retreatment will be 30 days.  The 6 Ibs. ai/A rate
is for ground application only.  Sprays must be directed toward the canopy.

Citrus orchard floors (granular formulations)

       The maximum number of applications per season will  be reduced from 10 to 3; the
maximum amount applied per season will be reduced from  10 Ibs. ai/A to 3 Ibs. ai/A.

Corn, field, sweet and seed (liquid formulations)

       The maximum number of applications per season will  be limited to 3; the maximum
amount applied per season will be reduced from 7.5 Ibs. ai/A to 3 Ibs. ai/A.

Corn, field, sweet and seed (granular formulations)

       The maximum number of applications per season will  be limited to 2; the maximum
amount applied per season will be limited to 2 Ibs. ai/A.
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Cotton (liquid formulations)

       The maximum number of applications per season will be reduced from 6 to 3; the
maximum amount applied per season will be reduced from 6 Ibs. ai/A to 3 Ibs. ai/A.

Peanuts (granular formulations)

       Aerial application will be eliminated.

Sorghum (liquid formulations)

       The maximum number of applications per season will be limited to 3; it was previously
unspecified.

Soybeans (liquid formulations)

       The maximum number of applications per season will be limited to 3; it was previously
unspecified.

Sugar beets (liquid formulations)

       The maximum number of applications per season will be reduced from 4 to 3; the
maximum amount applied per season will be reduced from 4 Ibs. ai/A to 3 Ibs. ai/A.

Sugar beets (granular formulations)

       The maximum number of applications per season, previously unspecified, will be limited
to 3; the maximum amount applied per season will be reduced from  13.5 Ibs. ai/A to 3 Ibs. ai/A.

Sunflowers (liquid formulations)

       The maximum number of applications per season, previously unspecified, will be limited
to 3; the maximum amount applied per season will be reduced from 4.5 Ibs. ai/A to 3 Ibs. ai/A.

Tobacco (liquid formulations)

       The maximum number of applications per year will be limited to 1; the application rate of
5 Ibs. ai/A for root-knot nematodes in North Carolina, South Carolina, and Virginia will be
eliminated;  the maximum amount applied per season will be reduced from 1.5 Ibs. ai/A to 1 Ib.
ai/A.
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Tree nuts (liquid formulations)

       The maximum amount applied per season will be reduced from 8 Ibs. ai/A to 4 Ibs. ai/A.

Walnut and almond orchard floors (liquid formulations):

       The maximum amount applied per season will be reduced from 8 Ibs. ai/A to 4 Ibs. ai/A;
the maximum number of applications per season, previously unspecified, will be limited to 2.

All crops

       Spray drift warnings and no-spray zones will be included on labels, as shown in Table
33. These no-spray zones will apply to rivers, natural ponds, lakes, streams, reservoirs, marshes,
estuaries and commercial fish ponds.  For more information on spray drift management
language,  please see section 4. Other Labeling, subsection b. Spray Drift Management.
            Table 33. Proposed No-Spray Buffer Zones around Water Bodies
Application Method
Ground Boom
Chemigation
Orchard Airblast
Aerial (fixed-wing or helicopter)
Required Setback (No-spray Zone)
25 feet
25 feet
50 feet
150 feet
       Table 34 summarizes the range of risk quotients for major use sites taking into account
the mitigation measures outlined above.

             Table 34.  Risk Quotients for Corn, Citrus, Cotton and Tobacco
                            With Proposed Risk Mitigation
Species
Freshwater Fish Acute LC50
Fish Reproduction NOAEC
Aquatic Invertebrate Acute LC50
Freshwater Invert. Reproduction NOAEC
Estuarine Fish Acute LC50
Estuarine Fish Reproduction NOAEC
Estuarine Invertebrate Acute LC50
Range of Risk Quotients
2.8- 11
8.9 -36 ' 5.4- 46 2
51-210
130 520 ' 65- 230 2
5.3-22
11-741 9.3- 20 2
110-590
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Estuarine Invert. Reproduction NOAEC
Estuarine Algae EC50
>11001
0.036-0.15
         1 Peak EECs in 2-meter deep pond or estuarine water
         2 21-day EECs in 2-meter deep pond or estuarine water
              4. Other Labeling

       In order to remain eligible for reregi strati on, other use and safety information needs to be
placed on the labeling of all end-use products containing chlorpyrifos. For the specific labeling
statements, refer to Section V of this document

                     a. Endangered Species Statement

       The Agency has developed the Endangered Species Protection Program to identify
pesticides whose use may cause adverse impacts on endangered and threatened species, and to
implement mitigation measures that address these impacts. The Endangered Species Act
requires federal agencies to ensure that their actions are not likely to jeopardize listed species or
adversely modify designated critical habitat. To analyze the  potential of registered pesticide
uses to affect any particular species, EPA puts basic toxicity  and exposure data developed for
REDs into context for individual listed species and their locations by  evaluating important
ecological parameters, pesticide use information, the geographic relationship between specific
pesticides uses and species locations, and biological requirements and behavioral aspects of the
particular species. This analysis will take into consideration  any regulatory changes
recommended in this RED that are being implemented at that time. A determination that there is
a likelihood of potential impact to a listed species may result in limitations on use of the
pesticide, other measures to mitigate any potential impact, or consultations with the Fish and
Wildlife  Service and/or the National Marine Fisheries Service as necessary.

       The Endangered Species Protection Program as described in a Federal Register notice (54
FR 27984-28008, July 3, 1989) is currently being implemented on an interim basis As part of
the interim program, the Agency has developed County Specific Pamphlets that articulate many
of the specific measures outlined in the Biological Opinions issued to date. These Pamphlets are
available for voluntary use by pesticide applicators, on EPA's web site at www.epa.gov/espp. A
final Endangered Species Protection Program, which may be altered from the interim program, is
scheduled to be proposed for public comment in the Federal Register  before the end of 2001.

                     b. Spray Drift Management

       The Agency is in the process of developing more appropriate label statements for spray
and dust  drift control to ensure that public health and the environment are protected from
unreasonable adverse effects.  In August 2001, EPA published draft guidance for label
statements in a pesticide registration (PR) notice ("Draft PR Notice 2001-X"
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http://www.epa.gov/PR Notices/#2001).  A Federal Register notice was published on August 22,
2001 (http://www.epa. gov/fedrgstr) Announcing the availability of this draft guidance for a 90-
day public comment period. After receipt and review of the comments, the Agency will publish
final guidance in a PR notice for registrants to use when labeling their products.

       Until EPA decides upon and publishes the final label guidance for spray and dust drift,
registrants (and applicants) may choose to use the statements proposed in the draft PR notice.
Registrants should refer to and read the draft PR notice to obtain a full understanding of the
proposed guidance and its intended applicability, exemptions for certain products, and the
Agency's willingness to consider other versions of the statements.

       For purposes of complying with the deadlines for label submission outlined in this
document, registrants (and applicants) may elect to adopt the appropriate sections of the
proposed language below, or a version that is equally protective, for their end-use product
labeling.

       For products as liquids:

       "Do not allow spray to drift from the application site and contact people, structures
       people occupy at any time and the associated property, parks and recreation areas,
       nontarget crops, aquatic and wetland areas, woodlands, pastures, rangelands or animals."

       "For ground boom applications, apply with nozzle height no more than 4 feet above the
       ground or crop canopy, and when wind speed is  10 mph or less at the application site as
       measured by an  anemometer. Use	(registrant to fill in blank with spray quality,
       e.g. fine or medium) or coarser spray according to ASAE 572 definition for standard
       nozzles or VMD for spinning atomizer nozzles."

       "For orchard and vineyard airblast applications,  do not direct spray above trees and vines,
       and turn off outward pointing nozzles at row ends and outer rows. Apply only when
       wind speed is 3 -10 mph at the application site as measured by an anemometer outside of
       the orchard or vineyard on the upwind side."

       "For aerial applications, the boom width must not exceed 75% of the wingspan or 90% of
       the rotary blade. Use upwind swath displacement, and apply only when wind speed is 3 -
       10 mph as measured by an anemometer. Use	(registrant to fill in blank with spray
       quality, e.g. fine or medium) or coarser spray according to ASAE 572 definition for
       standard nozzles or VMD for spinning atomizer nozzles. If application includes a no-
       spray zone, do not release spray at a height greater than 10 feet above the ground or the
       crop canopy."

       For hand-applied products, to be applied as sprays:
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       "Do not allow spray to drift from the application site, and contact people, structures
       people occupy at any time, and the associated property, parks and recreation areas,
       nontarget crops, aquatic and wetland areas, woodlands, pastures, rangelands, or animals.
       Apply only when wind speed is not more than 10 mph. For sprays, apply largest size
       droplets possible."

       Alternatively, registrants may elect to use the following language, which is the current
Agency policy on drift labeling. For products that are applied outdoors in liquid sprays (except
mosquito adulticides), regardless of application method:

       "Do not allow this product to drift."

       The Agency recognizes that the above option does not address other application types.
Registrants may therefore wish to adapt some variation of the old, and proposed new language
for their particular products, depending on their application methods.
V.  What Registrants Need to Do

       In order to be eligible for reregi strati on, registrants need to implement the risk mitigation
measures outlined in Section IV and V, which include, among other things, submission of the
following:

       For chlorpyrifos technical grade active ingredient products, registrants need
to submit the following items.

       Within 90 days from receipt of the generic data call-in (DCI):

       (1)    completed response forms to the generic DCI (i.e., DCI response form and
requirements status and registrant's response form); and

       (2)    submit any time extension and/or waiver requests with a full written
justification.

       Within the time limit specified in the generic DCI:

       (1)    Cite any existing generic data which address data requirements or submit
new generic data responding to the DCI.

       Please contact Tom Myers at 703/308-8589 with questions regarding generic
reregi strati on and/or the DCI. All materials submitted in response to the generic DCI should be
addressed:
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By US mail:
Document Processing Desk (DCI/SRRD)
Chemical Review Manager's Name
US EPA (7508C)
1200 Pennsylvania Ave., NW
Washington, DC 20460
By express or courier service:
Document Processing Desk (DCI/SRRD)
Chemical Review Manager's Name
Office of Pesticide Programs (7508C)
Room 266A, Crystal Mall 2
1921 Jefferson Davis Highway
Arlington, VA 22202
       For products containing the active ingredient chlorpyrifos, registrants need to
submit the following items for each product.

       Within 90 days from the receipt of the product-specific data call-in (PDCI):

       (1)    Complete response forms to the PDCI (i.e., PDCI response form and
requirements status and registrant's response form); and

       (2)    Submit any time extension or waiver requests with a full written
justification.
       For all products that have agricultural uses, items 1 through 5, listed below, are
       required to be submitted to the Agency within 45 days of receipt of the PDCI. Item
       number 6, the product specific data, is required within eight months from the
       receipt of the PDCI.
       Within eight months from the receipt of the PDCI:

       (1)    Two copies of the confidential statement of formula (EPA Form 8570-4);

       (2)    A completed original application for reregi strati on (EPA Form 8570-1).
Indicate on the form that it is an "application for reregi strati on";

       (3)    Five copies of the draft label incorporating all label amendments outlined
in Table 35 of this document;

       (4)    A completed form certifying compliance with data compensation
requirements (EPA Form 8570-34);

       (5)    If applicable, a completed form certifying compliance with cost share offer
requirements (EPA Form 8570-32); and

       (6)    The product-specific data responding to the PDCI.
                                         94

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       Please contact Venus Eagle at (703)308-8045 with questions regarding product
reregi strati on and/or the PDCI. All materials submitted in response to the PDCI should be
addressed:
By US mail:
Document Processing Desk (PDCI/PRB)
Chemical Review Manager's Name
US EPA (7508C)
1200 Pennsylvania Ave., NW
Washington, DC 20460
             By express or courier service only:
             Document Processing Desk (PDCI/PRB)
             Chemical Review Manager's Name
             Office of Pesticide Programs (7508C)
             Room 266A, Crystal Mall 2
             1921 Jefferson Davis Highway
                    Arlington, VA 22202
       A. Manufacturing Use Products

             1. Additional Generic Data Requirements

       The generic data base supporting the reregi strati on of chlorpyrifos for the above eligible
uses has been reviewed and determined to be substantially complete.  The following data gaps
remain:

       Product Chemistry Data requirements for the TGAI and Manufacturing-Use Products.
       830.1550 (formerly 61-1)    Product Identity and Disclosure of Ingredients
       830.1600 (formerly 61-2a)
       830.1670 (formerly 61-2b)
       830.1700 (formerly 62-1)
       830.1750 (formerly 62-2)
       830.1800 (formerly 62-3)
       830.6302 (formerly 63-2)
       830.6303 (formerly 63-3)
       830.6304 (formerly 63-4)
       830.7200 (formerly 63-5)
       830.7300 (formerly 63-7)
       830.7840 and 830.7860 (formerly 63-8) Solubility
       830.7950 (formerly 63-9)    Vapor Pressure
       830.7550 (formerly 63-11)
       830.6313 (formerly 63-13)
       830.6316 (formerly 63-16)
       830.6317 (formerly 63-17)
       830.6320 (formerly 63-20)
Starting Materials and Manufacturing Process
Discussion of Formation of Impurities
Preliminary Analysis
Certification of Limits
Analytical Method
Color
Physical State
Odor
Melting Point
Density, Bulk Density or Specific Gravity
Octanol/Water Partition Coefficient
Stability
Explodability
Storage Stability
Corrosion Characteristics
       Residue chemistry data requirements.
       860.1500 (formerly 171-4k)  Magnitude of the residue in corn fodder and forage
       860.1500 (formerly 171-4k)  Magnitude of the residue in cotton gin by-products
       860.1500 (formerly 171-4k)  Magnitude of the residue in clover and grasses
                                          95

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       860.1500 (formerly 171-4k)  Magnitude of the residue in aspirated grain fractions of
                                  sorghum, soybeans and wheat
       860.1500 (formerly 171-4k)  Magnitude of the residue in cherries
       Other data requirements:
       875.1100 and 875.1300
       875.1100 and 875.1300
       875.1100 and 875.1300

       875.1100 and 875.1300

       875.1100 and 875.1300
       875.1100 and 875.1300
       875.1100 and 875.1300

       875.2100 (formerly 132-la)

       233 and 234

       810.1000 (formerly 90-1)


       810.1000 (formerly 90-1)


       810.1000 (formerly 90-1)
       810.1000 (formerly 90-1)

       Summarize water monitoring
Exposure data for seed treatment uses.
Exposure data for dip applications (e.g., preplant peaches).
Exposure data for mixing wettable powders for
aerial/chemigation application.
Exposure data for loading and applying granulars for aerial
application.
Exposure data for groundboom application.
Exposure data for backpack spray application.
Exposure data for reentry into treated areas with soil
incorporated/directed applications.
Dislodgeable foliar residues on ornamentals in
greenhouses.
Risk Assessment data for treated wood in residential
structures.
Use pattern information for hydraulic handheld spray
applications (amounts handled per day, per season; types of
sprayers used).
Use pattern information for high pressure hand-wand spray
applications (amounts handled per day, per season; types of
sprayers used).
Use pattern information, i.e., timing of application relative
to postapplication activities, greenhouse DFR data, and
biological monitoring data to develop transfer coefficients
for various greenhouse/nursery activities are required.
Usage data to confirm the acres treated for the 3 Ib/A on
sodfarms for mole crickets.
data to confirm reduction of residue levels in surface water.
       Also, a Data Call-in Notice (DCI) was sent to registrants of organophosphate
pesticides currently registered under FIFRA (August 6, 1999 64FR42945-42947, August 18
64FR44922-44923). DCI requirements included acute, subchronic, and developmental
neurotoxicity studies.

             2. Labeling for Manufacturing Use Products

       To remain in compliance with FIFRA, manufacturing use product (MUP) labeling should
be revised to comply with all current EPA regulations, PR Notices and applicable policies.  The
MP labeling should bear the labeling contained in Table 38 at the  end of this section.
                                           96

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       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 product-specific
data regarding the pesticide after a determination of eligibility has been made.  Registrants must
review previous data submissions to ensure that they meet current EPA acceptance criteria and if
not, commit to conduct new studies. If a registrant believes that previously submitted data meet
current testing standards, then the study MRID numbers should be cited according to the
instructions in the Requirement Status and Registrants Response Form provided for each
product.

       A product-specific data call-in, outlining specific data requirements, accompanies this
interim RED.

              2. Labeling for End-Use Products

       Labeling changes are necessary to implement the mitigation measures outlined in Section
IV above. Specific language for these changes is specified in the Table 35.

       C. Existing Stocks

       Registrants may generally distribute and sell products bearing old labels/labeling for 26
months from the date of the issuance of this Interim Reregi strati on Eligibility Decision
document.  Persons other than the technical registrants may generally distribute or sell such
products for 50 months from the date of the issuance of this interim 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 registrant may distribute and sell chlorpyrifos products
bearing old labels/labeling for 26 months from the date of issuance of this interim RED. Persons
other than the technical registrants may distribute or sell such products for 50 months from the
date of the issuance of this interim RED. Registrants and persons other than the technical
registrants remain obligated to meet pre-existing label requirements and existing stocks
requirements applicable to products they sell or distribute.

       D. Labeling Changes Summary Table

       In order to be eligible for reregi strati on, amend all product labels to incorporate the risk
mitigation measures outlined in Section IV.  Table 35 describes how language on the labels
should be amended.
                                           97

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Table 35. Summary of Labeling Changes for Chlorpyrifos
Description
Amended Labeling Language
Placement on Label
Manufacturing Use Products
One of these statements
may be added to a label
to allow reformulation
of the product for a
specific use or all
additional uses
supported by a
formulator or user
group
Environmental Hazards
Statements Required by
the RED and Agency
Label Policies
"Only for formulation into an insecticide for the following use(s) [fill blank only with those uses that are being
supported by MP registrant]."
"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)."
Or
"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)."
This pesticide is toxic to birds and wildlife, and extremely toxic to fish and aquatic organisms. Do not discharge
effluent containing this product into lakes, streams, ponds, estuaries, oceans or other waters unless in accordance
with the requirements of a National Pollutant Discharge Elimination System (NPDES) permit and the permitting
authority has been notified in writing prior to discharge. Do not discharge effluent containing this product to sewer
systems without previously notifying the local sewage treatment plant authority. For guidance, contact your State
Water Board or Regional Office of the EPA.
Directions for Use
Directions for Use
Directions for Use
End Use Products Intended for Occupational Use
Products That Have Worker Protection Standard (WPS) Uses Only or Both WPS and Non WPS Uses on Same Label
Handler PPE
requirements (all
formulations)
Note the following information when preparing labeling for all end use products:
For sole-active-ingredient end-use products that contain chlorpyrifos, the product label must be revised to adopt
the handler personal protective equipment (PPE)/engineering control requirements set forth in this section. Any
conflicting PPE requirements on the current label must be removed.

                        98

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     Description
                                     Amended Labeling Language
 Placement on Label
                        For multiple-active-ingredient end-use products that contain chlorpyrifos, the handler PPE/engineering control
                        requirements set forth in this section must be compared with the requirements on the current label, and the more
                        protective language must be retained. For guidance on which requirements are considered to be more protective,
                        see PR Notice 93-7.

                        PPE that is established on the basis of Acute Toxicity testing with the end-use products must be compared with the
                        active ingredient PPE specified below in this document.  The more protective PPE must be placed in the product
                        labeling. For example, the Handler PPE in this RED does not require protective eyewear which may be required by
                        the Acute Toxicity testing for the end-use product.  For guidance on which PPE is considered more protective, see
                        PR Notice 93-7.
Handler PPE
requirements for liquid
formulation packaged
in containers holding
more than 2.5 gallons.
"Personal Protective Equipment (PPE)
Some materials that are chemical-resistant to this product are [registrant inserts correct material]. For more
information, following instructions in Supplement Three of PR Notice 93-7.  If you want more options, follow the
instructions for category [insert A,B,C,D,E,F,G or H] on an EPA chemical-resistance category selection chart."

"Mixers and loaders using a mechanical transfer loading system and applicators using aerial application equipment
must wear:

- long sleeved shirt and long pants;
- socks and shoes.

In addition to the above, mixers and loaders using a mechanical transfer loading system must wear:

- chemical resistant gloves;
- chemical resistant apron;
- a NIOSH-approved dust mist filtering respirator with MSHA/NIOSH approval number prefix TC-21C or a
  NIOSH-approved respirator any N, R, P, or HE filter.

See engineering controls for additional requirements
Immediately
following^elow
Precautionary
Statements: Hazards
to Humans and
Domestic Animals
                                                                      99

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     Description
                                      Amended Labeling Language
Placement on Label
                        All other mixers, loaders, applicators and handlers must wear:

                        - coveralls over long-sleeved shirt and long pants;
                        - chemical-resistant gloves;
                        - chemical resistant apron when mixing or loading or exposed to the concentrate;
                        - chemical-resistant footwear plus socks;
                        - chemical-resistant headgear for overhead exposures;
                        - a NIOSH-approved dust mist filtering respirator with MSHA/NIOSH approval number prefix TC-21C or a
                          NIOSH-approved respirator any N, R, P, or HE filter.

                        Note:  The registrant must drop the N-series filter from the respirator statement if the pesticide product contains
                        or is used with oil.
Handler PPE
requirements for liquid
formulation packaged
in containers holding
2.5 gallons or less.
"Personal Protective Equipment (PPE)
Some materials that are chemical-resistant to this product are" [registrant inserts correct material]. "For more
information, following instructions in Supplement Three of PR Notice 93-7.  If you want more options, follow the
instructions for category [insert A,B,C,D,E,F,G or H] on an EPA chemical-resistance category selection chart."

All mixers, loaders, other applicators and other handlers must wear:

- coveralls over long-sleeved shirt and long pants;
- chemical-resistant gloves;
- chemical resistant apron when mixing or loading or exposed to the concentrate;
- chemical-resistant footwear plus socks;
- chemical-resistant headgear for overhead exposures;
- a NIOSH-approved dust mist filtering respirator with MSHA/NIOSH approval number prefix TC-21C or a
  NIOSH-approved respirator any N, R, P, or HE filter.

Note:  The registrant must drop the N-series filter from the respirator statement if the pesticide product contains
or is used with oil.
                                                                      100

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     Description
                                      Amended Labeling Language
 Placement on Label
Handler PPE
requirements for
wettable powder
formulations.

(wettable powder
formulations must be in
water-soluble
packaging to be
eligible for
reregistration)
"Personal Protective Equipment (PPE)
Some materials that are chemical-resistant to this product are" [registrant inserts correct material]. " For more
information, following instructions in Supplement Three of PR Notice 93-7. If you want more options, follow the
instructions for category [insert A,B,C,D,E,F,G or H] on an EPA chemical-resistance category selection chart."

"Mixers and loaders must wear:

- long-sleeved shirt and long pants;
- socks and shoes;
- chemical resistant gloves;
- chemical resistant apron.

Applicators using aerial application equipment must wear:

- long-sleeved shirt and long pants;
- socks and shoes.

See engineering controls for additional requirements.

All other handlers must wear:

- coveralls over long-sleeved shirt and long pants;
- chemical-resistant gloves;
- chemical resistant apron when mixing or loading;
- chemical-resistant footwear plus socks;
- chemical-resistant headgear for overhead exposures;
- a NIOSH-approved dust mist filtering respirator with MSHA/NIOSH approval number prefix TC-21C or a
 NIOSH-approved respirator any N, R, P, or HE filter.

Note:  The registrant must drop the N-series filter from the respirator statement if the pesticide product contains
or is used with oil.
Immediately
following/below
Precautionary
Statements: Hazards
to Humans and
Domestic Animals
                                                                      101

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     Description
                                     Amended Labeling Language
 Placement on Label
Handler PPE
requirements for
granular products
"Personal Protective Equipment (PPE)
Some materials that are chemical-resistant to this product are" [registrant inserts correct material].  "For more
information, following instructions in Supplement Three of PR Notice 93-7.  If you want more options, follow the
instructions for category [insert A,B,C,D,E,F,G or H] on an EPA chemical-resistance category selection chart."

"Loaders, applicators and all other handlers must wear:

- coveralls over long-sleeved shirt and long pants;
- chemical-resistant gloves;
- chemical-resistant footwear plus socks;
- a NIOSH-approved dust mist filtering respirator with MSHA/NIOSH approval number prefix TC-21C or a
 NIOSH-approved respirator any N, R, P, or HE filter.
Immediately
following/below
Precautionary
Statements: Hazards
to Humans and
Domestic Animals
User Safety
Requirements
"Follow manufacturer's instructions for cleaning/maintaining PPE. If no such instructions for washables exist, use
detergent and hot water.  Keep and wash PPE separately from other laundry."

"Discard clothing and other absorbent materials that have been drenched or heavily contaminated with this
product's concentrate.  Do not reuse them."  (This second statement is not required for granular formulations)
Precautionary
Statements: Hazards
to Humans and
Domestic Animals
immediately following
the PPE requirements
                                                                     102

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     Description
                                     Amended Labeling Language
 Placement on Label
Engineering Controls
required for liquid
formulations packaged
in containers holding
more than 2.5 gallons.
"Engineering Controls"

"Mixers and loaders supporting aerial applications must use  a mechanical transfer system that meets the
requirements listed in the Worker Protection Standard (WPS) for agricultural pesticides [40 CFR 170.240(d)(4)]
for dermal protection, and must:
        ~ wear the personal protective equipment required above for mixers/loaders,
        ~ wear protective eyewear if the system operates under pressure, and
        ~ be provided and have immediately available for use in an emergency, such as a broken package, spill, or
        equipment breakdown: coveralls, chemical resistant footwear and chemical resistant headgear if overhead
        exposure."

"Pilots must use an enclosed cockpit in a manner that meets the requirements listed in the Worker Protection
Standard (WPS) for agricultural pesticides [40 CFR 170.240(d)(6)]."

"Use of human flaggers is prohibited. Mechanical flagging equipment must be used."

"When handlers use closed cab motorized ground application equipment 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."
Precautionary
Statements: Hazards
to Humans and
Domestic Animals
(Immediately
following PPE and
User Safety
Requirements.)
Engineering Controls
for liquid formulations
packaged in containers
less than 2.5 gallons.
"Engineering Controls"

"When handlers use closed systems or closed cab motorized ground application equipment 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."
Precautionary
Statements: Hazards
to Humans and
Domestic Animals
(Immediately
following PPE and
User Safety
Requirements.)
                                                                     103

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     Description
                                     Amended Labeling Language
 Placement on Label
Engineering controls
for wettable powder
formulations
"Engineering Controls"

"Water-soluble packets, when used correctly, qualify as a closed mixing/loading system under the Worker
Protection Standard (WPS) for Agricultural Pesticides [40 CFR 170.240(d)(4)]. Mixers and loaders using water-
soluble packets must wear the PPE required above for mixer/loaders, and have immediately available for use in
emergency (such as a broken package, spill or equipment breakdown) additional PPE.  These PPE include coveralls
and chemical-resistant footwear and a NIOSH-approved dust mist filtering respirator with MSHA/NIOSH approval
number prefix TC-21C or a NIOSH-approved respirator any N, R, P, or HE filter."

"Pilots must use an enclosed cockpit in a manner that meets the requirements listed in the Worker Protection
Standard (WPS) for agricultural pesticides [40 CFR 170.240(d)(6)]."

"Use of human flaggers is prohibited. Mechanical flagging equipment must be used."

"When applicators use closed cab motorized ground equipment 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."

Note:  The registrant must drop the N-series filter from the respirator statement if the pesticide product contains
or is used with oil.
Precautionary
Statements: Hazards
to Humans and
Domestic Animals
(Immediately
following PPE and
User Safety
Requirements.)
Engineering controls
for Granular
formulations
"Engineering Controls"

"Pilots must use an enclosed cockpit in a manner that meets the requirements listed in the Worker Protection
Standard (WPS) for agricultural pesticides [40 CFR 170.240(d)(6)]."

"When applicators use closed cab equipment 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."
Precautionary
Statements: Hazards
to Humans and
Domestic Animals
(Immediately
following PPE and
User Safety
Requirements.)
                                                                     104

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     Description
                                      Amended Labeling Language
 Placement on Label
User Safety
Recommendations
"User Safety Recommendations"

"Users should wash hands before eating, drinking, chewing gum, using tobacco or using the toilet."

"Users should remove clothing/PPE immediately if pesticide gets inside. Then wash thoroughly and put on clean
clothing."

"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."
Precautionary
Statements
immediately following
the Engineering
Controls
Environmental Hazards
"Environmental Hazards"

"This pesticide is toxic to fish, aquatic invertebrates, small mammals and birds. Do not apply directly to water, or
to areas where surface water is present or to intertidal areas below the mean high water mark. Drift and runoff may
be hazardous to aquatic organisms in water adjacent to treated areas. Do not contaminate water when disposing of
equipment wash water or rinsate.

This product is highly toxic to bees exposed to direct treatment or residues on blooming crops or weeds. Do not
apply this product or allow it to drift to blooming crops or weeds if bees are visiting the treatment area."
Precautionary
Statements
immediately following
the User Safety
Recommendations
Restricted-Entry
Interval
"Do not enter or allow entry into treated areas during the restricted entry interval (REI).  The REI for each crop is
listed in the directions for use associated with each crop"
Directions for Use,
Agricultural Use
Requirements Box
WPS Restricted Entry
Intervals (REI)
The Directions for Use must be amended to reflect the following REI:

The REI for all crops except those listed below is 24 hours

cauliflower: 3 days
citrus trees: 5 days
fruit trees: 4 days
Directions for Use
Under Application
Instructions for Each
Crop
                                                                      105

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     Description
                                      Amended Labeling Language
 Placement on Label
Early Re-entry
Personal Protective
Equipment established
by the RED.
"PPE required for early entry into treated areas that is permitted under the Worker Protection Standard and
involves contact with anything that has been treated, such as plants, soil, or water, is:

Coveralls over short sleeved shirt and shirt pants;
Chemical resistant gloves made out of any waterproof material;
Chemical resistant footwear plus socks;
Chemical Resistant headgear for over head exposures."

"Notify workers of the application by warning them orally and by posting warning signs at entrances to treated
areas."
Directions for Use,
Agricultural Use
Requirements Box
Entry Restrictions for
products applied as
sprays that have Non-
WPS uses on the label
"Do not enter or allow others to enter until sprays have dried"
Directions for Use in
the Non-Agricultural
Use Requirements
Box.
General 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."

Labels must be amended to reflect the following application restrictions which supercede or are in addition to
restrictions currently on labels:

Preharvest interval restrictions:

All crops 7 days except:

cauliflower: 21-30 days
nut trees: 14 days
citrus trees: 21 days
fruit trees: 21 days

Aerial application restrictions:
All formulations:  "Aerial application to peanuts is prohibited."
Granular formulations: "Do not apply by aircraft at a rate greater than 1 Ib. ai/A."
Place in the Direction
for Use
                                                                       106

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Description
Amended Labeling Language
Placement on Label
                   Maximum application rates for a single application:
                   - golf course turf: lib. ai/A
                   - citrus: 4 Ibs.  ai/A, except in Fresno, Tulare, Kern, Kings and Madera Counties, in California, where it may be
                   applied at 6 Ibs. ai/A for control of red scale by ground application.
                   - tobacco (liquids): 2 Ibs. ai/A
                   - tobacco (granulars): 3 Ibs. ai/A
                   -corn l.Olb/A
                   Maximum number of applications per season:
                   - alfalfa (liquids):  4
                   - citrus orchard floors (granulars):  3
                   - corn (field, sweet, seed) (granulars):  2
                   - sorghum (liquids): 3
                   - sugar beets (liquids): 3
                   - sunflowers (liquids): 3
                   - walnut and almond orchard floors (liquids):  2
           - citrus (liquids): 2
           - corn (field, sweet, seed) (liquids): 3
           -cotton(liquids):  3
           - soybeans (liquids):  3
           - sugar beets (granulars):  1
           -tobacco (liquids): 1
                   Maximum amount a.i to be applied per acre per season:
                   - citrus (granulars) use on orchard floors: 3 Ibs. ai/A
                   - corn (field, sweet, seed) (liquids): 3 Ibs. ai/A
                   - corn (field, sweet, seed) (granulars): 2 Ibs. ai/A
                   - cotton (liquids): 3 Ibs. ai/A
                   - sugar beets (liquids): 3 Ibs ai/A
                   - walnut and almond orchard floors (liquids): 4 Ibs. ai/A
                   - sugar beets (granulars): 2 Ibs ai/A
                   - tobacco (liquids): 2 Ibs ai/A
                   - tree nuts (liquids): 4 Ibs. ai/A
                   - sunflowers (liquids): 3 Ibs. ai/A
                                                                   107

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     Description
                                      Amended Labeling Language
Placement on Label
Spray drift restrictions
for outdoor products
applied as sprays.
"Do not allow spray to drift from the application site and contact people, structures people occupy at any time and
the associated property, parks and recreation areas, nontarget crops, aquatic and wetland areas, woodlands,
pastures, rangelands, or animals."

        "For ground boom applications, do not apply within 25 feet of rivers, natural ponds, lakes, streams,
        reservoirs, marshes, estuaries and commercial fish ponds. Apply with nozzle height no more than 4 feet
        above the ground or crop canopy and when wind speed is 10 mph or less at the application site as
        measured by an anemometer.  Use (registrant to fill in blank with spray quality, e.g. fine or medium) or
        coarser spray according to ASAE 572 definition for standard nozzles or VMD for spinning atomizer
        nozzles."

        "For orchard/vineyard airblast applications, do not apply within 50 feet of rivers, natural ponds, lakes,
        streams, reservoirs, marshes, estuaries and commercial fish ponds.  Direct spray above trees/vines and turn
        off outward pointing nozzles at row ends and outer rows. Apply only when wind speed is 3 -10 mph at
        the application site as measured by an anemometer outside of the orchard/vineyard on the upwind side."

        "For aerial applications, do not apply within 150 feet of rivers, natural ponds, lakes,  streams, reservoirs,
        marshes, estuaries and commercial fish ponds.  The boom width must not exceed 75% of the wingspan or
        90% of the rotary blade. Use upwind swath displacement and apply only when wind speed is 3 ~ 10 mph
        as measured by an anemometer. Use	(registrant to fill in blank with spray quality, e.g. fine or
        medium) or coarser spray according to ASAE 572 definition for standard nozzles or VMD for spinning
        atomizer nozzles. If application includes a no-spray zone, do not release spray at a height greater than 10
        feet above the ground or the crop canopy."

        "For overhead chemigation, do not apply within 25 feet of rivers, natural ponds, lakes, streams,
        reservoirs, marshes, estuaries and commercial fish ponds. Apply only when wind speed is 10 mph or less."

        "The applicator also must use  all other measures necessary to control drift."
                                                                                                                                   Directions for Use in
                                                                                                                                   General Precautions
                                                                                                                                   and Restrictions
                                                                       108

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     Description
                                     Amended Labeling Language
 Placement on Label
                                                   End Use Products Intended for Occupational Use
                               Products That Have Only Non-Worker Protection Standard (Non-WPS) Uses on the Label
Handler PPE
requirements (all
formulations)
Note the following information when preparing labeling for all end use products:

For sole-active-ingredient end-use products that contain chlorpyrifos, the product label must be revised to adopt
the handler personal protective equipment (PPE)/engineering control requirements set forth in this section. Any
conflicting PPE requirements on the current label must be removed.

For multiple-active-ingredient end-use products that contain chlorpyrifos, the handler PPE/engineering control
requirements set forth in this section must be compared with the requirements on the current label, and the more
protective language must be retained. For guidance on which requirements are considered to be more protective,
see PR Notice 93-7.

PPE that is established on the basis of Acute Toxicity testing with the end-use products must be compared with the
active ingredient PPE specified below in this document. The more protective PPE must be placed in the product
labeling.  For example, the Handler PPE in this RED does not require protective eyewear which may be required by
the Acute Toxicity testing for the end-use product.  For guidance on which PPE is considered more protective, see
PR Notice 93-7.
Handler PPE
requirements for liquid
formulations'
"Personal Protective Equipment (PPE)

All mixers, loaders, applicators and handlers must wear:

- coveralls over long-sleeved shirt and long pants;
- chemical-resistant gloves such as (insert glove type as per Supplement Three of PR Notice 93-7);
- chemical resistant apron when mixing or loading or exposed to the concentrate;
- chemical-resistant footwear plus socks;
- chemical-resistant headgear for overhead exposures;
- a NIOSH-approved dust mist filtering respirator with MSHA/NIOSH approval number prefix TC-21C or a
 NIOSH-approved respirator any N, R, P, or HE filter."

Note:  The registrant must drop the N-series filter from the respirator statement if the pesticide product contains
or is used with oil.
Immediately
following/below
Precautionary
Statements: Hazards
to Humans and
Domestic Animals
                                                                     109

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     Description
                                     Amended Labeling Language
 Placement on Label
Handler PPE
requirements for
wettable powder
formulations.

(wettable powder
formulations must be in
water-soluble
packaging to be
eligible for
reregistration)
"Personal Protective Equipment (PPE)

Mixers and loaders must wear:

- long-sleeved shirt and long pants;
- socks and shoes;
- chemical resistant gloves such as (Registrant inserts glove type as per Supplement Three of PR Notice 93-7);
- chemical resistant apron.

Applicators using motorized ground boom application equipment must wear:

- long-sleeved shirt and long pants;
- socks and shoes.

See engineering controls for additional requirements.

All other handlers must wear:

- coveralls over long-sleeved shirt and long pants;
- chemical-resistant gloves;
- chemical resistant apron when mixing or loading;
- chemical-resistant footwear plus socks;
- chemical-resistant headgear for overhead exposures;
- a NIOSH-approved dust mist filtering respirator with MSHA/NIOSH approval number prefix TC-21C or a
 NIOSH-approved respirator any N, R, P, or HE filter."

Note:  The registrant must drop the N-series filter from the respirator statement if the pesticide product contains
or is used with oil.
Immediately
following/below
Precautionary
Statements: Hazards
to Humans and
Domestic Animals
                                                                     110

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     Description
                                     Amended Labeling Language
 Placement on Label
Handler PPE
requirements for
granular products1
"Personal Protective Equipment (PPE)

"Loaders, applicators and all other handlers must wear:
-long-sleeved shirt and long pants;
-socks and shoes.

In addition to the above,  loaders must wear:

-chemical-resistant gloves such as (registrant inserts glove type as per Supplement Three of PR Notice 93-7.);
-chemical-resistant apron;
-a NIOSH-approved dust mist filtering respirator with MSHA/NIOSH approval number prefix TC-21C or a
 NIOSH-approved respirator any N, R, P, or HE filter.

Note:  The registrant must drop the N-series filter from the respirator statement if the pesticide product contains
or is used with oil.
Immediately
following/below
Precautionary
Statements: Hazards
to Humans and
Domestic Animals
User Safety
Requirements
"Follow manufacturer's instructions for cleaning/maintaining PPE. If no such instructions for washables exist, use
detergent and hot water.  Keep and wash PPE separately from other laundry."

"Discard clothing and other absorbent materials that have been drenched or heavily contaminated with this
product's concentrate.  Do not reuse them."  (This second statement is not required for granular formulations)
Precautionary
Statements: Hazards
to Humans and
Domestic Animals
immediately following
the PPE requirements
Engineering Controls
requirements for liquid
formulations
"Engineering Controls"

"When handlers use closed cab motorized ground application equipment 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."
                                                                     Ill

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     Description
                                     Amended Labeling Language
 Placement on Label
Engineering Controls
requirements for
wettable powder
formulations for
products in water-
soluble packaging
"Engineering Controls"

"Water-soluble packets, when used correctly, qualify as a closed mixing/loading system. Mixers and loaders using
water-soluble packets must wear the PPE required above for mixer/loaders, and have immediately available for use
in emergency (such as a broken package, spill or equipment breakdown) additional PPE. These PPE include
coveralls and chemical-resistant footwear and a non-powered air purifying respirator equipped with an N-, R- or P-
series filter."

"When handlers use closed cab motorized ground application equipment 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
Recommendations
"User Safety Recommendations"

"Users should wash hands before eating, drinking, chewing gum, using tobacco or using the toilet."

"Users should remove clothing/PPE immediately if pesticide gets inside. Then wash thoroughly and put on clean
clothing."

"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."
Placed in a box in the
Precautionary
Statements under
Hazards to Humans
and Domestic
Animals immediately
following Engineering
Controls.
Entry Restrictions for
products applied as
sprays
"Do not enter or allow others to enter until sprays have dried"
Directions for Use
under Application
Restrictions.
Entry Restrictions for
granular products
"Do not enter or allow others to enter until dusts have settled"
Directions for Use
under Application
Restrictions.
                                                                     112

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       Description
                                      Amended Labeling Language
 Placement on Label
 Application
 Restrictions (all
 applicable
 formulations)
"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."

The following statement should be placed on labels of products used on either golf course turf or manhole covers:

      "The maximum application rate per application is 1 Ib. ai/A."

      "Do not use this product on manhole covers in storm drain systems."
Directions For Use
under General
Precautions and
Restrictions
  Spray drift restrictions
  for outdoor products
  applied as sprays.
"Do not allow spray to drift from the application site and contact people, structures people occupy at any time and
the associated property, parks and recreation areas, nontarget crops, aquatic and wetland areas, woodlands,
pastures, rangelands, or animals.

        For ground boom applications, do not apply within 25 feet of rivers, natural ponds, lakes, streams,
        reservoirs, marshes, estuaries and commercial fish ponds. Apply with nozzle height no more than 4 feet
        above the ground or crop canopy and when wind speed is 10 mph or less at the application site as
        measured by an anemometer. Use (registrant to fill in blank with spray quality, e.g. fine or medium) or
        coarser spray according to ASAE 572 definition for standard nozzles or VMD for spinning atomizer
        nozzles.

The applicator also must use all other measures necessary to control drift."
Directions for Use
under Application
Restrictions.
1 PPE that is established on the basis of Acute Toxicity of the end-use product must be compared to the active ingredient PPE in this document. The more
protective PPE must be placed in the product labeling. For guidance on which PPE is considered more protective, see PR Notice 93-7.

2 If the product contains oil or bears instructions that will allow application with an oil-containing material, the "N" designation must be dropped.

Instructions in the Labeling Changes section of Table 35 appearing in quotations represent the exact language that should appear on the label.

Instructions in the Labeling Changes section of Table 35 not in quotes represents actions that the registrant should take to amend their labels or product
registrations.
                                                                        113

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VI. Related Documents and How to Access Them

       This interim Reregi strati on Eligibility Document is supported by documents that are
presently maintained in the OPP docket. The OPP docket is located in Room 119, Crystal Mall #2,
1921 Jefferson Davis Highway, Arlington, VA. It is open Monday through Friday, excluding legal
holidays from 8:30 am to 4 pm..

       The docket initially contained preliminary risk assessments and related documents as of
October 17, 1999. Sixty days later the first public comment period closed. The EPA then
considered comments, revised the risk assessment, and added the formal "Response to Comments"
document and the revised risk assessment to the docket on August 16, 2000.

       All documents, in hard copy form, may be viewed in the OPP docket room or downloaded
or viewed via the Internet at the following site: "http://www.epa.gov/pesticides/op."
VII. Appendices
                                          114

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Appendix A. Table of Chlorpyrifos Use Patterns Eligible for Reregistration
                                   115

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Appendix A. Food/Feed Use Patterns Subject to Reregistration for Chlorpyrifos (Case 0100).
Site
Application Type
Application Timing
Application Equipment
Form
Max. Single
Application Rate
(ai)
Max. # Apps.
Min.
Retreatment
Interval
(Days)
Use Limitations
Crop Uses
Alfalfa
Soil in-furrow treatment
At planting
Ground equipment
Broadcast application
Foliar or postemergence
Ground, sprinkler
irrigation, or aerial
equipment
Broadcast application
Foliar
Ground or aerial
equipment
15% G
4 Ib/gal EC
2 Ib/gal EC
lib/A
lib/A
0.5 Ib/A
1
1 (per cutting)
4 (per season)
1 (per cutting)
4 (per season)
Not
Applicable
(NA)
10
10
Use limited to MO. A 21 -day PFfl/PGI has been established.
A 7-day PHI (rates <0.25 Ib ai/A), a 14-day PHI (rates <0.5
Ib ai/A), and a 21-day PHI (rates >0.5 Ib ai/A) have been
established.
Use limited to AZ and CA. A 4-day Pffl/PGI (rates 0.375-
0.5 Ib ai/A) has been established.
Almonds
Spray application
Dormant/delayed
dormant
Ground equipment
Spray application
Dormant/delayed
dormant
Ground equipment
Spray application
Foliar
Ground or aerial
equipment
50% WP
1 Ib/gal EC
4 Ib/gal EC
50% WP
50% DF
1 Ib/gal EC
4 Ib/gal EC
2 Ib/A or
2 lb/100 gal
0.5 lb/100 gal
[200-600 gal
finished spray /A,
1 Ib/A - 3 lb/Al
21b/A
or
2 lb/100 gal
1
1
3
NA
NA


Application may be made alone or as a tank mix with
petroleum spray oil. Grazing of meat or dairy animals in
treated orchards is prohibited.
A 14-day PHI has been established. Grazing of livestock in
treated orchards is prohibited (Section 3 and CA940017).
116

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Appendix A. Food/Feed Use Patterns Subject to Reregistration for Chlorpyrifos (Case 0100).
Site
Application Type
Application Timing
Application Equipment
Form
Max. Single
Application Rate
(ai)
Max. # Apps.
Min.
Retreatment
Interval
(Days)
Use Limitations
Almonds (cont.)
Trunk spray (bark)
application
Ground equipment
Soil broadcast
application
Orchard floor
Ground equipment
Soil broadcast
application
Orchard floor
Ground equipment
4 Ib/gal EC
4 Ib/gal EC
4 Ib/gal EC
21b/A
41b/A
31b/100galwith
1.5 gal spray /tree
1
2
2
--
-
—
Use limited to CA (CA940013).
Grazing of livestock in treated orchards is prohibited.
A 14-day PHI has been established. Grazing of livestock in
treated orchards is prohibited.
Use limited to CA (CA940024). Grazing of livestock in
treated orchards is prohibited.
Apples
Spray application
Dormant/delayed
dormant
Ground equipment
Spray application
- branches and trunk
Dormant/delayed dormant
1 Ib/gal EC
4 Ib/gal EC
4 Ib/gal EC
0.5 lb/100 gal
[200-600 gal
finished spray /A]
2.0 Ib/A
1
1
NA

Application may be made alone or as a tank mix with
petroleum spray oil. Grazing of meat or dairy animals in
treated orchards is prohibited.
Use restricted to CA (Section 24(c) CA940013)
117

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Appendix A. Food/Feed Use Patterns Subject to Reregistration for Chlorpyrifos (Case 0100).
Site
Application Type
Application Timing
Application Equipment
Form
Max. Single
Application Rate
(ai)
Max. # Apps.
Min.
Retreatment
Interval
(Days)
Use Limitations
Asparagus
Broadcast foliar
application
Preharvest
Ground equipment
Broadcast application
Postharvest (fem stage)
Ground equipment
4 Ib/gal EC
4 Ib/gal EC
lib/A
lib/A
1
2
NA
10
Use limited to AZ, CA, the Midwest, and Pacific Northwest.
A 1-day PHI has been established.
Use limited to AZ, CA, the Midwest, and Pacific Northwest.
Bananas
Fruit bag (shroud)
application
l%Impr
--
--
--
Shrouds are installed on the stem after all fruit bunches have
formed and are removed at harvest.
Bean (field, green, kidney, lima, navy, snap, string and wax)
Slurry seed treatment
Preplan!
Slurry seed treatment
Stored seed
50% WP
50% WP
1 oz/cwt
19.3 oz/23.5 gal
[3 fl.oz/cwt]
(1)
(1)
--
--
Grazing/feeding of livestock on bean hay grown from treated
seed is prohibited. Treated seeds may not be used for food,
feed, or oil purposes.
Use limited to TX. Treated seeds may not be used for food,
feed, or oil purposes.
Broccoli
Soil band treatment At
planting/transplanting
Ground equipment or
Directed spray
application
Post- transplant
Ground equipment
0.5% G
1%G
15%G
1 Ib/gal EC
4 Ib/gal EC
1.4oz/l,000ft.
of row
1
NA
Maximum seasonal application rates of 2.25 Ib ai/A (0.5-
15% G and 4 Ib/gal EC) and 2.6 Ib ai/A (1 Ib/gal EC) are in
effect. A 30-day PHI has been established for the EC
formulations.
118

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Appendix A. Food/Feed Use Patterns Subject to Reregistration for Chlorpyrifos (Case 0100).
Site
Application Type
Application Timing
Application Equipment
Form
Max. Single
Application Rate
(ai)
Max. # Apps.
Min.
Retreatment
Interval
(Days)
Use Limitations
Broccoli (continued)
Soil band treatment
At planting
Ground equipment
Soil injected sidedress
application
Broadcast application
Foliar
Ground or aerial
equipment
4 Ib/gal EC
4 Ib/gal EC
50% WP
1.4oz/l,000ft.
of row
1.3oz/l,000ft.
of row
lib/A
2
1
3
10
NA
10
Use limited to CA (CA940016). Maximum seasonal
application rate of 2.25 Ib ai/A is in effect. Application may
be repeated at thinning time as a directed spray. A 30-day
PHI has been established.
A 30-day PHI has been established.
A 21 -day PHI has been established. Application may be
made alone or as a tank mix with other pesticides
(AZ870006, AZ940003, CA860066, CA940001).
Broccoli Raab (rapini)
Soil application
At planting
Ground equipment
Broadcast application
Foliar
Ground or aerial
equipment
4 Ib/gal EC
50% WP
2.25 Ib/A
lib/A
1
3
NA
10
Section 24(c) CA9400 15.
40-day PHI. Section 24(c) AZ870006, AZ940003,
CA860066, CA940001
119

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Appendix A. Food/Feed Use Patterns Subject to Reregistration for Chlorpyrifos (Case 0100).
Site
Application Type
Application Timing
Application Equipment

Form

Max. Single
Application Rate
(ai)

Max. # Apps.
Min.
Retreatment
Interval
(Days)

Use Limitations
Brussels sprouts
Soil band treatment
At
planting/transplanting
Ground equipment
or
Directed spray
application
Post- transplant
Ground equipment
Soil band treatment
At planting
Ground equipment
Broadcast application
Foliar
Ground or aerial
equipment
Broadcast application
Foliar
Ground or aerial
equipment
0.5% G
1%G
15%G
1 Ib/gal EC
4 Ib/gal EC

4 Ib/gal EC
4 Ib/gal EC

50% WP

1.4oz/l,000ft.
of row


1.4oz/l,000ft.
of row
lib/A

lib/A

1



2
3

3

NA



10
10

10

See "Broccoli."



See "Broccoli."
A 21 -day PHI has been established.

See "Broccoli."

120

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Appendix A. Food/Feed Use Patterns Subject to Reregistration for Chlorpyrifos (Case 0100).
Site
Application Type
Application Timing
Application Equipment
Form
Max. Single
Application Rate
(ai)
Max. # Apps.
Min.
Retreatment
Interval
(Days)
Use Limitations
Cabbage
Soil band treatment
At planting
Ground equipment or
Directed spray
application
Post- transplant
Ground equipment
Soil band treatment
At planting
Ground equipment
Soil injected sidedress
application
Broadcast application
Foliar
Ground or aerial
equipment
0.5% G
1%G
15%G
1 Ib/gal EC
4 Ib/gal EC
4 Ib/gal EC
4 Ib/gal EC
50% WP
1.4oz/l,000ft.
of row
1.4oz/l,000ft.
of row
1.3oz/l,000ft.
of row
lib/A
1
2
1
3
NA
--
NA
10
See "Broccoli."
See "Broccoli."
See "Broccoli."
See "Broccoli."
Carrot (grown for seed)
Broadcast application
Foliar, After Bolting
Ground or aerial
equipment
4 Ib/gal EC
lib/A
—
—
Use limited to WA (WA940002). Feeding of treated carrot
cuttings or seed screenings to livestock or grazing of
livestock in treated areas is prohibited.
121

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Appendix A. Food/Feed Use Patterns Subject to Reregistration for Chlorpyrifos (Case 0100).
Site
Application Type
Application Timing
Application Equipment
Form
Max. Single
Application Rate
(ai)
Max. # Apps.
Min.
Retreatment
Interval
(Days)
Use Limitations
Cauliflower
Soil band treatment At
planting/transplanting
Ground equipment
Soil band treatment
At planting
Ground equipment
or Directed spray
application
Post- transplant
Ground equipment
Soil band treatment At
planting
Ground equipment
Broadcast application
Foliar
Ground or aerial
equipment
0.5% G
1%G
15%G
1 Ib/gal EC
4 Ib/gal EC
4 Ib/gal EC
50% WP
1.4oz/l,000ft.
of row
1.2oz/l,000ft.
of row
1.2oz/l,000ft.
of row or 2 Ib/A
lib/A
1
1
2
3
NA
NA
10
10
See "Broccoli."
Maximum seasonal application rate of 2 Ib ai/A is in effect.
A 30-day PHI has been established.
Use limited to CA (CA960016). Maximum seasonal
application rate of 2 Ib ai/A is in effect. A 30-day PHI has
been established.
See "Broccoli."
Cherries
Trunk spray (bark)
application
Foliar and postharvest
and/or dormant/delayed
dormant
Ground equipment
1 Ib/gal EC
4 Ib/gal EC
3 lb/100 gal
3
10
Use limited to sweet cherries. One of the three permitted
applications per season may be applied as a dormant spray
tank mixed with petroleum spray oil at 0.5 Ib ai/100 gal. A
6-day PHI has been established. Grazing of meat or dairy
animals in treated orchards is prohibited.
122

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Appendix A. Food/Feed Use Patterns Subject to Reregistration for Chlorpyrifos (Case 0100).
Site
Application Type
Application Timing
Application Equipment
Form
Max. Single
Application Rate
(ai)
Max. # Apps.
Min.
Retreatment
Interval
(Days)
Use Limitations
Cherries (continued)
Spray application
Foliar
Ground or aerial
equipment
50% WP
1 Ib/gal EC
1.51b/A
or
1.51b/100gal
8
10
Use limited to sour (tart) cherries. A 14-day PHI has been
established. Grazing of livestock in treated orchards is
prohibited.
Chinese broccoli (gai Ion)
Soil application
At planting
Ground equipment
Broadcast application
Foliar
Ground or aerial
equipment
4 Ib/gal EC
50% WP
2.25 Ib/A
1 Ib/gal
1
3
NA
10
See "Broccoli raab."
See "Broccoli."
Chinese cabbage (bok choy, napa)
Soil band treatment
At
planting/transplanting
Ground equipment
or
Directed spray
application
Post- transplant
Ground equipment
Soil application
At planting
rrronnH pqnipmpnt
0.5% G
1%G
15%G
1 Ib/gal EC
4 Ib/gal EC
4 Ib/gal EC
1.4oz/l,000ft.
of row
2.25 Ib/A
1
1
NA
NA
See "Broccoli."
See "Broccoli."
123

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Appendix A. Food/Feed Use Patterns Subject to Reregistration for Chlorpyrifos (Case 0100).
Site
Application Type
Application Timing
Application Equipment
Form
Max. Single
Application Rate
(ai)
Max. # Apps.
Min.
Retreatment
Interval
(Days)
Use Limitations
Chinese cabbage (bok choy, napa) (continued)
Broadcast application
Foliar
Ground or aerial
equipment
50% WP
lib/A
3
10
See "Broccoli." (AZ870006, AZ940003, CA860066,
CA940001)
Chinese mustard (gai choy)
Broadcast application
Foliar
Ground or aerial
equipment
50% WP
lib/A
3
10
See "Broccoli, raab."
Citrus
Spray application
Foliar
Ground or aerial
equipment
Spray application
Foliar
Ground or aerial
equipment
Spray application
Foliar
rrronnH pqnipmpnt
4 Ib/gal EC
4 Ib/gal EC
4 Ib/gal EC
6 Ib/A (rates
above 4 Ib/A are
limited to 5
counties in
California)
3.5 Ib/A
0.5 lb/100 gal
1
2
2
30
30
30
Maximum seasonal application rate of 7.5 Ib ai/A is in effect.
A 21-day PHI (rates < 3.5 Ib ai/A) and a 35-day PHI (rates >
3.5 Ib ai/A) have been established. Grazing of livestock in
treated areas is prohibited. Application may be made alone
or as a tank mix with other pesticides.
Maximum seasonal application rate of 7.5 Ib ai/A is in effect.
A 21-day PHI (rates < 3.5 Ib ai/A) and a 35-day PHI (rates >
3.5 Ib ai/A) have been established. Grazing of livestock in
treated areas is prohibited. Application may be made alone
or as a tank mix with other pesticides.
Use limited to residential citrus. A 21-day PHI has been
established.
124

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Appendix A. Food/Feed Use Patterns Subject to Reregistration for Chlorpyrifos (Case 0100).
Site
Application Type
Application Timing
Application Equipment
Form
Max. Single
Application Rate
(ai)
Max. # Apps.
Min.
Retreatment
Interval
(Days)
Use Limitations
Citrus (continued)
Spray application
Foliar
Ground or aerial
equipment
Trunk spray application
Foliar
Ground equipment
Fiberglass band
application
Foliar
Ground equipment
Soil broadcast
application
Postplant (grove floor)
Ground or sprinkler
irrigation equipment
1 Ib/gal EC
4 Ib/gal EC
4 Ib/gal EC
15% G
4 Ib/gal EC
0.4 lb/100 gal
0.625 Ib/A
2.5 Ib/A
lib/A
2
4
4
3
30
--
—
10
Maximum seasonal application rate of 2 Ib ai/A is in effect.
A 21 -day PHI has been established.
Use limited to CA. A 28-day PHI has been established.

Maximum seasonal application rate of 3 Ib ai/A is in effect.
A 28-day PHI has been established. Grazing of livestock in
treated areas is prohibited. For use in FL, a maximum
seasonal rate of 3 Ib ai/A (EC) is in effect.
Clover (grown for seed)
Soil broadcast
application
Preplan!
Ground equipment
or
Broadcast application
Foliar
Ground equipment
4 Ib/gal EC
21b/A
1

Use limited to OR (OR940031). Grazing or feeding of
treated clover cuttings or seed screenings or using of hay for
livestock is prohibited.1"
125

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Appendix A. Food/Feed Use Patterns Subject to Reregistration for Chlorpyrifos (Case 0100).
Site
Application Type
Application Timing
Application Equipment
Form
Max. Single
Application Rate
(ai)
Max. # Apps.
Min.
Retreatment
Interval
(Days)
Use Limitations
Collards
Soil band treatment
At
planting/transplanting
Ground equipment
or
Directed spray
application
Post- transplant
Ground equipment
0.5% G
1%G
15%G
1 Ib/gal EC
4 Ib/gal EC
1.4oz/l,000ft.
of row
1
NA
See "Broccoli."
Collards (continued)
Broadcast application
Foliar
Ground or aerial
equipment
50% WP
lib/A
3
10
See "Broccoli, Raab."
Corn: field or sweet or pop or grown for seed
Soil incorporated
treatment
Ground equipment
Soil treatment
At planting
Ground equipment
Soil treatment or
broadcast application
Ground or aerial
equipment
15% G
0.5% G
1%G
7.5% G
15%G
15%G
21b/A
2.4oz/l,000ft.
of row or 2 Ib/A
1.2oz/l,000ft.
of row
(1)
(1)
(1)
NA
NA
NA
Maximum seasonal application rate of 2 Ib ai/A is in effect.
A 35-day PHI (com grain), a 14-day PGI (corn silage), and a
35-day PFI (com fodder) have been established.
126

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Appendix A. Food/Feed Use Patterns Subject to Reregistration for Chlorpyrifos (Case 0100).
Site
Application Type
Application Timing
Application Equipment
Form
Max. Single
Application Rate
(ai)
Max. # Apps.
Min.
Retreatment
Interval
(Days)
Use Limitations
Corn: field or sweet or pop or grown for seed (continued)
Soil incorporated
treatment
Preplan!
Ground equipment
Soil broadcast
application
Preplant, at planting, or
preemergence
Ground equipment
Broadcast application
Postemergence/foliar
Ground, aerial, or
sprinkler irrigation
equipment
4 Ib/gal EC
4 Ib/gal EC
4 Ib/gal EC
31b/A
lib/A
1.51b/A
(1)
(1)
(5)
NA
NA
10
Maximum seasonal application rate of 3 Ib ai/A is in effect.
A 35-day PHI (com grain), a 14-day PGI (corn silage), and a
35-day PFI (com fodder) have been established. Application
may be made alone or as a tank mix with other pesticides.

Corn: Sweet
Broadcast application
Foliar
Ground, aerial, or
sprinkler irrigation
equipment
Broadcast application
Foliar
Ground or aerial
equipment
4 Ib/gal EC
4 Ib/gal EC
lib/A
0.5 Ib/A
3
3
10
10
Use limited to FL and GA. Maximum seasonal application
rate of 3 Ib ai/A is in effect. A 21 -day PHI (corn ears), PGI,
and PFI (corn silage, fodder, or grain) have been established.
Use limited to DE (DE930004), A 7-day PHI has been
established. Grazing of livestock in treated areas and feeding
treated corn silage, forage, or fodder to meat or dairy animals
is prohibited.11
127

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Appendix A. Food/Feed Use Patterns Subject to Reregistration for Chlorpyrifos (Case 0100).
Site
Application Type
Application Timing
Application Equipment
Form
Max. Single
Application Rate
(ai)
Max. # Apps.
Min.
Retreatment
Interval
(Days)
Use Limitations
Corn: Field and Sweet
Slurry seed treatment
Preplan!
Slurry seed treatment
Stored seed
50% WP
50% WP
1 oz/cwt
19.3 oz/23.5 gal
[3 floz/cwt]
(1)
(1)
--
--
Treated seeds may not be used for food, feed, or oil
purposes.
See "Bean."
Cotton
Broadcast application
Foliar
Ground, sprinkler
irrigation, aerial
equipment
Broadcast application
Foliar
Ground or aerial
equipment
Slurry seed treatment
Stored seed
Gin trash treatment
Ground equipment
4 Ib/gal EC
2 Ib/gal EC
50% WP
4 Ib/gal EC
lib/A
0.5 Ib/A
19.3 oz/23.5 gal
[3 floz/cwt]
1 Ib per 20 tons
of gin trash
3
3
(1)
--
10
10
--
--
A 14-day PHI has been established. Grazing of livestock in
treated areas and feeding of gin trash or treated forage to
livestock is prohibited.1"
Use limited to AZ and CA. A 40-day PHI has been
established. Grazing of livestock in treated areas and feeding
of gin trash or treated forage to livestock is prohibited.11
Applications may be made undiluted at the same rate.
See "Bean."
Use limited to MS.
Cranberry
Broadcast application
Foliar
Ground, aerial, or
sprinkler irrigation
equipment
4 Ib/gal EC
1.51b/A
2
10
A 60-day PHI has been established. Application may not be
made when bogs are flooded.
128

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Appendix A. Food/Feed Use Patterns Subject to Reregistration for Chlorpyrifos (Case 0100).
Site
Application Type
Application Timing
Application Equipment
Form
Max. Single
Application Rate
(ai)
Max. # Apps.
Min.
Retreatment
Interval
(Days)
Use Limitations
Cucumbers
Slurry seed treatment
Preplan!
50% WP
1 oz/cwt
(1)
--
Treated seeds may not be used for food, feed, or oil
purposes.
Figs
Soil incorporated
treatment
Dormant
Ground equipment
4 Ib/gal EC
21b/A
1
NA
Use limited to CA. A 210-day PHI has been established.
Filberts
Spray application
Foliar
Ground or aerial
equipment
50% WP
1 Ib/gal EC
4 Ib/gal EC
21b/A
or
2 lb/100 gal
3
—
A 14-day PHI has been established. Grazing of livestock in
treated orchards is prohibited.
Grapefruit
Spray application
Foliar
Ground or aerial
equipment
Spray application
Foliar or transplant
Ground or aerial
equipment
Spray application
Foliar
Ground equipment
4 Ib/gal EC
4 Ib/gal EC
4 Ib/gal EC
61b/A
3.5 Ib/A
0.5 lb/100 gal
2
2
2
30
30
30
See "Citrus."
See "Citrus."
See "Citrus."
129

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Appendix A. Food/Feed Use Patterns Subject to Reregistration for Chlorpyrifos (Case 0100).
Site
Application Type
Application Timing
Application Equipment
Form
Max. Single
Application Rate
(ai)
Max. # Apps.
Min.
Retreatment
Interval
(Days)
Use Limitations
Grapefruit (continued)
Spray application
Foliar
Ground or aerial
equipment
1 Ib/gal EC
0.4 lb/100 gal
2
30
See "Citrus."
Grapes
Directed spray soil
application
Ground equipment
Directed spray soil
application
Ground equipment
Directed spray soil
application
Ground equipment
Spray/drench
application
Prebloom
Ground equipment
Broadcast foliar
application
Nonbearing
Ground or aerial
equipment
1 Ib/gal EC
4 Ib/gal EC
4 Ib/gal EC
4 Ib/gal EC
4 Ib/gal EC
4 Ib/gal EC
2.25 lb/100 gal
[2 qt finished
spray/15 sq. ft.]
1.125 lb/100 gal
[2 qt finished
spray per 1 5 sq.
ft]
lib/A
lib/A
lib/A
1
2
3
1

NA
—
--
NA

Use limited to states east of the Rocky Mountains. A 35-day
PHI has been established.
Use limited to TN (TN940001). A 35-day PHI has been
established.
Use limited to CA (CA940018). A 76-day PHI has been
established.
Use limited to MI and MO (MI940001 and MO940001).
Use limited to ID, OR, and WA (ID940013, OR940030, and
WA940003).
130

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Appendix A. Food/Feed Use Patterns Subject to Reregistration for Chlorpyrifos (Case 0100).
Site
Application Type
Application Timing
Application Equipment
Form
Max. Single
Application Rate
(ai)
Max. # Apps.
Min.
Retreatment
Interval
(Days)
Use Limitations
Grass (grown for seed)
Broadcast application
Foliar
Ground or aerial
equipment
4 Ib/gal EC
lib/A
3
—
Use limited to OR and NV (OR940032 and NV940002).
Grazing of livestock in treated areas or feeding treated grass,
straw, or seed screenings to livestock or using hay for
livestock bedding is prohibited.b
Kale
Soil band treatment
At
planting/transplanting
Ground equipment
or
Directed spray
application
Post- transplant
Ground equipment
Broadcast application
Foliar
Ground or aerial
equipment
0.5% G
1%G
15%G
1 Ib/gal EC
4 Ib/gal EC
50% WP
1.4oz/l,000ft.
of row
lib/A
1
3
NA
10
See "Broccoli."
See "Broccoli."
Kohlrabi
Soil band treatment
At
planting/transplanting
Ground equipment
or
Directed spray
application
Post- transplant
Ground equipment
0.5% G
1%G
15%G
1 Ib/gal EC
4 Ib/gal EC
1.4oz/l,000ft.
of row
1
NA
See "Broccoli."
131

-------
Appendix A. Food/Feed Use Patterns Subject to Reregistration for Chlorpyrifos (Case 0100).
Site
Application Type
Application Timing
Application Equipment
Form
Max. Single
Application Rate
(ai)
Max. # Apps.
Min.
Retreatment
Interval
(Days)
Use Limitations
Kohlrabi (continued)
Broadcast application
Foliar
Ground or aerial
equipment
50% WP
lib/A
3
10
See "Broccoli."
Lemon
Spray application
Foliar
Ground or aerial
equipment
Spray application
Foliar or transplant
Ground or aerial
equipment
Spray application
Foliar
Ground equipment
Spray application
Foliar
Ground or aerial
equipment
4 Ib/gal EC
4 Ib/gal EC
4 Ib/gal EC
1 Ib/gal EC
61b/A
3.5 Ib/A
0.5 lb/100 gal
0.4 lb/100 gal
2
2
2
2
30
30
30
30
See "Citrus."
See "Citrus."
See "Citrus."
See "Citrus."
Macadamia Nuts
Trunk spray (bark)
application
Ground equipment
50% WP
lib/A
8
30
Use limited to HI (FH930010 and FH93001 1). Maximum
seasonal application rate of 8 Ib ai/A is in effect. A 14-day
PHI has been established. Grazing of livestock in treated
areas is prohibited.
132

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Appendix A. Food/Feed Use Patterns Subject to Reregistration for Chlorpyrifos (Case 0100).
Site
Application Type
Application Timing
Application Equipment
Form
Max. Single
Application Rate
(ai)
Max. # Apps.
Min.
Retreatment
Interval
(Days)
Use Limitations
Mint - Peppermint
Soil incorporated
treatment
Preplan!
Ground equipment
Broadcast foliar
application
Preharvest and
postharvest
Ground or sprinkler
irrigation equipment
4 Ib/gal EC
1 Ib/gal EC
4 Ib/gal EC
21b/A
21b/A
1
1 preharvst +
1 postharvest
NA
NA
Use limited to OR (OR940027). Application following a
broadcast foliar spray is not permitted.
A 90-day PHI has been established.
Mustard greens
Broadcast application
Foliar
Ground or aerial
equipment
50% WP
lib/A
3
10
See "Broccoli."
Nectarines
Spray application
Dormant/delayed
dormant
Branches and Trunk
Ground equipment
Spray application
Dormant/delayed
dormant
Branches and Trunk
Ground equipment
1 Ib/gal EC
4 Ib/gal EC
4 Ib/gal EC
0.5 lb/100 gal
[200-600 gal
finished spray /A,
1 lb/A-3 Ib/A]
11 Ib/A
1
1
NA
NA
Application may be made alone or as a tank mix with
petroleum spray oil. Grazing of meat or dairy animals in
treated orchards is prohibited.
Use limited to CA (CA940013)
133

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Appendix A. Food/Feed Use Patterns Subject to Reregistration for Chlorpyrifos (Case 0100).
Site
Application Type
Application Timing
Application Equipment
Form
Max. Single
Application Rate
(ai)
Max. # Apps.
Min.
Retreatment
Interval
(Days)
Use Limitations
Nectarines (continued)
Trunk spray (bark)
application
Ground equipment
1 Ib/gal EC
4 Ib/gal EC
3 lb/100 gal
1
NA
A 14-day PHI has been established. Grazing of meat or
dairy animals in treated orchards is prohibited.
Onions, bulb
Soil application
At seeding
Ground equipment
Soil drench application
At seeding
Ground equipment
Soil drench application
Post planting
Ground equipment
0.5% G
1%G
15%G
1 Ib/gal EC
4 Ib/gal EC
4 Ib/gal EC
0.035 lb/1, 000 ft.
of row
0.04 lb/1,000 ft.
of row (1 Ib/gal
EC)
0.03 lb/1, 000 ft.
of row (4 Ib/gal
EC)
lib/A
1
1
2
NA
NA

Maximum seasonal application rate of 1 Ib ai/A is in effect
for the 1 5% G formulation.

Use limited to MI (MI940002. 60 day PHI. Total number of
applications should include both at planting and post crop
uses.
Oranges
Spray application
Foliar
Ground or aerial
equipment
Spray application
Foliar or transplant
Ground or aerial
equipment
4 Ib/gal EC
4 Ib/gal EC
61b/A
3.5 Ib/A
2
2
30
30
See "Citrus."
See "Citrus."
134

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Appendix A. Food/Feed Use Patterns Subject to Reregistration for Chlorpyrifos (Case 0100).
Site
Application Type
Application Timing
Application Equipment
Form
Max. Single
Application Rate
(ai)
Max. # Apps.
Min.
Retreatment
Interval
(Days)
Use Limitations
Oranges (continued)
Spray application
Foliar
Ground equipment
Spray application
Foliar
Ground or aerial
equipment
4 Ib/gal EC
1 Ib/gal EC
0.5 lb/100 gal
0.4 lb/100 gal
2
2
30
30
See "Citrus."
See "Citrus."
Peaches
Spray application
Dormant/delayed
dormant
Ground equipment
Trunk spray (bark)
application
Ground equipment
Dip application
Preplan! (nonbearing)
1 Ib/gal EC
4 Ib/gal EC
4 Ib/gal EC
4 Ib/gal EC
0.5 lb/100 gal
[200-600 gal
finished spray /A]
3 lb/100 gal
3 lb/100 gal
1
1
1
NA
NA
NA
See "Nectarines."
See "Nectarines."

135

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Appendix A. Food/Feed Use Patterns Subject to Reregistration for Chlorpyrifos (Case 0100).
Site
Application Type
Application Timing
Application Equipment
Form
Max. Single
Application Rate
(ai)
Max. # Apps.
Min.
Retreatment
Interval
(Days)
Use Limitations
Peanuts
Soil incorporated
treatment
Preplan!
Ground equipment
Soil band application
At planting, postplant,
or early pegging
Ground equipment
Broadcast application
Prior to or at pegging
Directed spray
application
Foliar
Ground equipment
4 Ib/gal EC
0.5% G
1%G
15%G
15% G
1 Ib/gal EC
21b/A
2.25 ozai/1, 000
ft. of row
(2 Ib/A)
1.95 Ib/A
21b/A
1
2
--
1
NA
NA
10
NA
A combined maximum seasonal application rate of 4 Ib ai/A
is in effect for preplan! and postplant use. A 21 -day PHI has
been established. Feeding peanut forage or hay to meat or
dairy animals is prohibited.
A maximum seasonal application rate of 4.5 oz ai/1,000 ft. of
row or 4 Ib ai/A for the 15% G formulation is in effect. A
maximum seasonal rate of 2.25 oz ai/1,000 ft. of row is in
effect. A 21-day PHI has been established. Feeding peanut
forage or hay to meat or dairy animals is prohibited.
A maximum seasonal application rate of 4 Ib ai/A is in effect.
A 21 -day PHI has been established. Feeding peanut forage
or hay to meat or dairy animals is prohibited.
A 21 -day PHI has been established. A maximum seasonal
application rate of 2 Ib ai/A is in effect.
Pears
Spray application
Dormant/delayed
dormant
Ground equipment
Spray application
Dormant/delayed
dormant Branches and
Trunk
1 Ib/gal EC
4 Ib/gal EC
4 Ib/gal EC
0.5 lb/100 gal
[200-600 gal
finished spray /A]
21b/A
1
1
NA
NA
See "Apples."
Use limited to CA (CA940013).
136

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Appendix A. Food/Feed Use Patterns Subject to Reregistration for Chlorpyrifos (Case 0100).
Site
Application Type
Application Timing
Application Equipment
Form
Max. Single
Application Rate
(ai)
Max. # Apps.
Min.
Retreatment
Interval
(Days)
Use Limitations
Peas (black-eyed, field, and garden)
Slurry seed treatment
Preplan!
Slurry seed treatment
Stored seed
50% WP
50% WP
1 oz/cwt
19.3 oz/23.5 gal
[3 floz/cwt]
(1)
(1)
--
--
See "Bean."
See "Bean."
Pecans
Spray application
Foliar
Ground or aerial
equipment
Soil broadcast
application
Orchard floor
Ground equipment
50% WP
50% DF
1 Ib/gal EC
4 Ib/gal EC
50% WP
1 Ib/gal EC
4 Ib/gal EC
1 lb/100 gal or
lib/A (50% WP,
50% DF, and
1 Ib/gal EC)
2 Ib/A (4 Ib/gal
EC)
1 lb/100 gal or
1 Ib/A (50% WP
and 1 Ib/gal EC)
2 Ib/A (4 Ib/gal
EC)
5
5


A maximum seasonal application rate of 10 Ib ai/A is in
effect for the 4 Ib/gal EC formulation. Application may be
made alone or as a tank mix with other pesticides. A 28-day
PHI has been established. The grazing of livestock in treated
orchards is prohibited.

Peppers
Broadcast application
Foliar
Ground equipment
Broadcast application
Foliar
Ground equipment
50% WP
50% WP
lib/A
lib/A
8
8
-

Use limited to FL and GA (FL920007, FL 920009,
GA930003, and GA930004). A 7-day PHI has been
established.
Use limited to NM and TX (NM95001). A 14 day PHI has
been established.
137

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Appendix A. Food/Feed Use Patterns Subject to Reregistration for Chlorpyrifos (Case 0100).
Site
Application Type
Application Timing
Application Equipment
Form
Max. Single
Application Rate
(ai)
Max. # Apps.
Min.
Retreatment
Interval
(Days)
Use Limitations
Plum/Prune
Spray application
Dormant/delayed
dormant
Ground equipment
Spray application
Dormant/delayed
dormant
Ground or aerial
equipment
1 Ib/gal EC
4 Ib/gal EC
4 Ib/gal EC
0.5 lb/100 gal
[200-600 gal
finished spray /A,
1 Ib/A -3 lb/Al
21b/A
1
1
NA
NA
See "Apples."
Use limited to CA (CA940013)
Pumpkin
Slurry seed treatment
Preplan!
50% WP
1 oz/cwt
(1)
--
See "Bean."
Radish
Soil in-furrow treatment
At planting
Ground equipment
0.5% G
1%G
15%G
1 Ib/gal EC
4 Ib/gal EC
0.5oz/l,000ft.
of row (2. 75
Ib/A)
1
NA
A maximum seasonal application rate of 2.75 Ib ai/A is in
effect for the 0.5-15% G, 1 Ib/gal EC and 4 Ib/gal EC
formulations.
Radish (grown for seed)
Soil incorporated
treatment
Preplant
Ground equipment
4 Ib/gal EC
21b/A
(1)
NA
Use limited to OR (OR94033). Grazing of livestock in
treated areas or the feeding of radish cuttings or seed
screenings to livestock is prohibited.
138

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Appendix A. Food/Feed Use Patterns Subject to Reregistration for Chlorpyrifos (Case 0100).
Site
Application Type
Application Timing
Application Equipment
Form
Max. Single
Application Rate
(ai)
Max. # Apps.
Min.
Retreatment
Interval
(Days)
Use Limitations
Rape
Broadcast application
Foliar
Ground or aerial
equipment
50% WP
lib/A
3
10
See "Broccoli."
Rutabagas
Soil band treatment
At
planting/transplanting
Ground equipment
Soil band treatment
At planting
Ground equipment
0.5% G
1%G
15%G
4 Ib/gal EC
1 Ib/gal EC
1.4oz/l,000ft.
of row (2.25
Ib/A)
1.6oz/l,000ft.
of row (2.25
Ib/A)
1.3oz/l,000ft.
of row
1
1
1
NA
NA
NA
Maximum seasonal application rate of 2.25 Ib ai/A is in
effect. The use of rutabaga tops for food/feed purposes is
prohibited.
Maximum seasonal application rate of 1.9 Ib ai/A is in effect.
The use of rutabaga tops for food/feed purposes is prohibited.
139

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Appendix A. Food/Feed Use Patterns Subject to Reregistration for Chlorpyrifos (Case 0100).
Site
Application Type
Application Timing
Application Equipment

Form

Max. Single
Application Rate
(ai)

Max. # Apps.
Min.
Retreatment
Interval
(Days)

Use Limitations
Sorghum
Soil T-band
incorporated treatment
At planting
Ground equipment
Broadcast application
Foliar
Ground, sprinkler
irrigation, or aerial
equipment
or
Directed spray
application
Foliar
Ground equipment
Slurry seed treatment
Stored seed
15%G

4 Ib/gal EC





50% WP
8oz/l,000ft. of
row(1.51b/A)
lib/A





19.3 oz/23.5 gal
[3 fl.oz/cwtl
1

3





(1)
NA

10





NA


Maximum seasonal application rate of 1.5 Ib ai/A is in effect.
A 30-day PHI/PGI/PFI for rates 0.5 Ib ai/A and a 60-day
PFfl/PGI/PFI for rates >0.5 Ib ai/A have been established.
Use on sweet sorghum is prohibited.




See "Bean."
140

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Appendix A. Food/Feed Use Patterns Subject to Reregistration for Chlorpyrifos (Case 0100).
Site
Application Type
Application Timing
Application Equipment
Form
Max. Single
Application Rate
(ai)
Max. # Apps.
Min.
Retreatment
Interval
(Days)
Use Limitations
Soybean
Soil T-band
incorporated treatment
At planting or
postemergence
Ground equipment
Soil band application
At planting
Ground equipment or
Directed soil band
application,
Postemergence
Ground equipment or
Broadcast spray
application
Foliar
Ground, sprinkler
irrigation, or aerial
equipment
15%G
4 Ib/gal EC
1.2oz/l,000ft.
of row
lib/A
1
3
NA
14 (between
final two
applications)

Maximum seasonal application rate of 3 Ib ai/A is in effect.
A 28-day PHI has been established. Grazing of livestock in
treated areas or the feeding of treated soybean forage, hay,
and straw to meat or dairy animals is prohibited.
Strawberry
Soil incorporated
treatment
Preplant
Ground equipment
Broadcast foliar
application
Prebloom
Ground equipment
4 Ib/gal EC
1 Ib/gal EC
4 Ib/gal EC
21b/A
lib/A
1
2
NA
10
Use limited to ID, OR, and WA (ID940012, OR940035, and
WA94004) Application made one year before harvest
season.
A 21 -day PHI has been established.
141

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Appendix A. Food/Feed Use Patterns Subject to Reregistration for Chlorpyrifos (Case 0100).
Site
Application Type
Application Timing
Application Equipment



Form

Max. Single
Application Rate
(ai)



Max. # Apps.
Min.
Retreatment
Interval
(Days)



Use Limitations
Strawberry (continued)
Broadcast foliar
application
Prebloom
Ground equipment
Directed spray
application
Postharvest
Ground equipment
1 Ib/gal EC
4 Ib/gal EC


4 Ib/gal EC



lib/A



lib/A



1 pre-plant
2 foliar


2



10 (foliar)



14



A 21 -day PHI has been established.



Use limited to OR (OR940034).



Sugar beet
Soil T-band application
At planting or
postemergence (two- to
four- leaf stage)
Ground equipment
Soil incorporated
treatment
Preplan!
Ground equipment
or
Soil band application
At planting
Ground equipment
15% G




4 Ib/gal EC







1.35oz/l,000ft.
of row or
2 Ib/A (based on
a 22-inch row
spacing)
4.6oz/100ftrow
(30 in row) or
lib/A





1




(1)







NA




NA












Maximum seasonal application rate of 4 Ib ai/A is in effect.
A 30-day PHI/PGI have been established. Application may
be made alone or as a tank mix with other pesticides.





142

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Appendix A. Food/Feed Use Patterns Subject to Reregistration for Chlorpyrifos (Case 0100).
Site
Application Type
Application Timing
Application Equipment
Form
Max. Single
Application Rate
(ai)
Max. # Apps.
Min.
Retreatment
Interval
(Days)
Use Limitations
Sugar beet (continued)
Broadcast application
Foliar
Ground or aerial
equipment
or
Soil band application
Foliar
Ground equipment
4 Ib/gal EC
lib/A
3
10
Maximum seasonal application rate of 4 Ib ai/A is in effect.
A 30-day PHI/PGI have been established.
Sugar beet (grown for seed)
Soil broadcast
application
Preplant
Ground equipment
4 Ib/gal EC
21b/A
1 - fall before
harvest season
NA
Use limited to ID and OR (ID950018 and OR940028).
Sunflower
Soil band application
At planting
Ground equipment
Soil incorporated
treatment
Preplant
Ground equipment
Broadcast foliar
application
Postemergence
Ground or aerial
equipment
0.5% G
1%G
15%G
4 Ib/gal EC
4 Ib/gal EC
1.25oz/l,000ft.
of row
21b/A
1.51b/A
1
1
3
NA
NA
7

Maximum seasonal application rate of 3 Ib ai/A is in effect.
A 42-day PHI has been established. Grazing of livestock in
treated areas is prohibited.
143

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Appendix A. Food/Feed Use Patterns Subject to Reregistration for Chlorpyrifos (Case 0100).
Site
Application Type
Application Timing
Application Equipment
Form
Max. Single
Application Rate
(ai)
Max. # Apps.
Min.
Retreatment
Interval
(Days)
Use Limitations
Sweet Potato
Soil incorporated
treatment
Preplan!
Ground equipment
0.5% G
1%G
15%G
1 Ib/gal EC
4 Ib/gal EC
21b/A
1
NA
A 125-day PHI has been established.
Tobacco
Soil incorporated
treatment
Pre-transplant
Ground equipment
Soil incorporated
treatment
Pre-transplant
Ground equipment
15%G
4 Ib/gal EC
4 Ib/gal EC
31b/A
21b/A
1
1
NA
NA

Tank mix use in all tobacco growing regions.
Turnip
Soil band treatment
At
planting/transplanting
Ground equipment
or
Directed spray
application
Post- transplant
Ground equipment
0.5% G
1%G
15%G
1 Ib/gal EC
4 Ib/gal EC
1.4oz/l,000ft.
of row
1
NA
See "Broccoli."
144

-------
Appendix A. Food/Feed Use Patterns Subject to Reregistration for Chlorpyrifos (Case 0100).
Site
Application Type
Application Timing
Application Equipment
Form
Max. Single
Application Rate
(ai)
Max. # Apps.
Min.
Retreatment
Interval
(Days)
Use Limitations
Walnuts
Spray application
Dormant/delayed
dormant
Ground or aerial
equipment
Spray application
Foliar
Ground or aerial
equipment
Soil spray application
Ground equipment
50% WP
50% WP
50% DF
1 Ib/gal EC
4 Ib/gal EC
4 Ib/gal EC
21b/A
or
2 lb/100 gal
21b/A
or
2 lb/100 gal
41b/A
1
2
2
NA
-


A 14-day PHI has been established. Grazing of livestock in
treated orchards is prohibited.
A 14-day PHI has been established. Grazing of livestock in
treated orchards is prohibited. Ant control for orchard floors.
Wheat
Broadcast application
Foliar
Ground, sprinkler
irrigation, or aerial
equipment
4 Ib/gal EC
0.5 Ib/A
2

A 14-day PHI for forage and hay, and a 28-day PHI for grain
and straw have been established.
145

-------
Appendix A. Food/Feed Use Patterns Subject to Reregistration for Chlorpyrifos (Case 0100).
Site
Application Type
Application Timing
Application Equipment
Form
Max. Single
Application Rate
(ai)
Max. # Apps.
Min.
Retreatment
Interval
(Days)
Use Limitations
Animal uses
Cattle (beef, calves, and lactating and non-lactatin
Ear tag treatment
5% Impr
* dairy)
Two ear
tags/animal
--
--
One tag is attached to each ear when pests first appear in the
spring. Tags may be replaced as needed.
Outdoor turkey pens
Soil treatment
Before turkeys are
transferred to pens
Ground equipment
50% WP
50% DF
41b/A
2
28
Direct application to turkeys is prohibited. A 7-day PSI has
been established. Open feed should be covered during
spraying and water troughs should be flushed out
immediately after spraying operations.
Food-handling establishment uses
Food-Handling Establishments
Spot and/or crack and
crevice treatment
Coarse low pressure
sprayer or paint brush
Spot and/or crack and
crevice treatment
Coarse low pressure
sprayer or paint brush
1 Ib/gal
Mcap
1.71b/gal
Mcap
2 Ib/gal EC
4 Ib/gal EC
0.5% RTU
0.5% spray
0.5% spray
—

14
7

Applications may be repeated at 7-day intervals in food
service establishments and every 14 days in other types of
food handling establishments. Emergency application may
be made 2 days after the last treatment; limited to one
emergency treatment per month.
a Unless protective clothing is worn.
b According to Table 1 (OPPTS, 860.1000) label restrictions on these commodities are not practical and will no longer be accepted.
                                                                        146

-------
Appendix B.  Table of Generic Data Requirements and Studies Used to Make the
             Reregistration Decision
                                  147

-------
                           APPENDIX B
Data Supporting Guideline Requirements for the Reregistration of Chlorpyrifos
REQUIREMENT
USE
PATT
CITATION(S)

PRODUCT CHEMISTRY
New
Guideline
Number
830.1550
830.1600
830.1670
830.1700
830.1750
830.1800
830.6302
830.6303
830.6304
830.7200
830.7300
830.7840
830.7860
830.7950
830.7370
Old
Guid.
Number
61-1
61-2A
61-2B
62-1
62-2
62-3
63-2
63-3
63-4
63-5
63-7
63-8
63-9
63-10
Guideline Name
Product Identity and Composition
Start. Mat. & Mnfg. Process
Formation of Impurities
Preliminary Analysis
Certification of limits
Analytical Method
Color
Physical State
Odor
Melting Point
Density
Solubility
Vapor Pressure
Dissociation Constant

All
All
All
All
All
All
All
All
All
All
All
All
All
All
MRID

00146506, 00146508, 45434001, data gap for MPs
00146506, 00146508, 40105301, 40411301,
MPs
00146506, 00146508, 40105301, 42495401,
MPs
00146506, 00146508, 40144101, 42544901,
MPs
00146506, 00146508, 40105301, 45434001,
00146506, 00146508, 40144101, 45434001,
MPs
00146506, 00146508, data gap for MPs
00146506, 00146508, data gap for MPs
00146506, 00146508, data gap for MPs
00146506, 00146508, data gap for MPs
00146506, 00146508, 42495402, 41747202,
00146506, 00146508, data gap for MPs
00146506, 00146508, data gap for MPs
N/A
45434001, data gap for
45434001, data gap for
45434001, data gap for
data gap for MPs
42527203, data gap for




data gap for MPs



                                 148

-------
                                                      APPENDIX B
                      Data Supporting Guideline Requirements for the Reregistration of Chlorpyrifos
REQUIREMENT
830.7550
830.7000
830.6313
830.6314
830.6315
830.6316
830.6317
830.7100
830.6319
830.6320
830.7050
63-11
63-12
63-13
63-14
63-15
63-16
63-17
63-18
63-19
63-20
None
Octanol/Water Partition Coefficient
pH
Stability
Oxidizing/Reducing Action
Flammability
Explodability
Storage Stability
Viscosity
Miscibility
Corrosion characteristics
UV/Visible Absorption
USE
PATT
All
All
All
All
All
All
All
All
All
All
A,B
CITATION(S)
00146506, 00146508, 42652601, data gap for MPs
N/A
00146506, 00146508, data gap for MPs
41742705, 43428701
N/A
00146506, 43046602, 43428702, data gap for MPs
00146506, 00146508, 41747204, 43633901, data gap for MPs
N/A
N/A
00146506, 00146508, 41653503, 42527201, data gap for MPs
data gap for MPs
ECOLOGICAL EFFECTS
850.2100

850.2200

850.2200
850.2400
850.2300
850.2300
71-2A     Avian Dietary Toxicity - Quail

71-2B     Avian Dietary Toxicity - Duck
71-3       Earthworm Toxicity
71-4A     Avian Reproduction - Quail
71-4B     Avian Reproduction - Duck
A,B    00046954, 40854701,41043901,41885201,44057101,44057102,
       44585403
A,B    00046955,00095123,00095304,00095305,40854703,41965502,
       44055101,44062601, 44585401
A,B    00046958,00095007,00095446,00095449,40854702,41965501
A,B    00078524,00095371,
A,B    00046951,42144902
A,B    00046952,00046953,42144901
                                                              149

-------
                                                       APPENDIX B
                       Data Supporting Guideline Requirements for the Reregistration of Chlorpyrifos
REQUIREMENT
 USE
PATT
CITATION(S)
850.1075       72-1A     Fish Toxicity - Bluegill


850.1075       72-1C     Fish Toxicity, Rainbow Trout

850.1010       72-2A     Invertebrate Toxicity
                        Invertebrate Toxicity TEP

                        Estuarine/Marine Toxicity - Fish

                        Estuarine/Marine Toxicity - Mollusk

                        Estuarine/Marine Toxicity - Shrimp

                        Fish- Early Life Stage

                        Estuarine Field Studies
850.1500       72-5       Life Cycle Fish

                        Terrestrial Field Toxicity Study


850.4400       123-2      Aquatic Plant Growth

850.3020       141-1      Honey Bee Acute Contact

                        Water Monitoring
850.1010
None
None
None
None
None
72-2B
72-3A
72-3B
72-3C
72-4A

A,B   00095013,00095125,00095298,00095296,00095321,00154732,
       40840904,41043903,41885203

A,B   00095013,00095297, 00155781,40840903,41885204

A,B   00024400,00095338,00095365,00095366,00095368,00095370,
       00102520,00154727,05000774,05000821,05000841,40840902,
       41073401

A,B   41885202

A,B   00102758, 00154718, 42144904

A,B   42144905, 42495405,42495406

A,B   00095363,42144906,42245902

A,B   00154732,41043903

A,B   00095130,00095301,00095367,00104696,00158261,05000928,
       41205409,41228801,44585408

A,B   42834401,00154721

A,B   00095114,42144903,43483101,43483102,43730301,43706701,
       43785201,43785202,44692001, 44709401

A,B   00024400,41063402

A,B   00040602, 00060632,41654701

A,B   43065601,43760601,43760602,43760603,43760604,43760605,
       43760608,43760609,43760610,43760611,43786901,43823901,
       43853201,43853202,43918301,44033401,44033402,44223601,
       44235001,44711601,45013101,43319201. Data gap for collection of
       water monitoring data to confirm reduction of residues in surface
       water.
                                                                150

-------
                                                       APPENDIX B
                      Data Supporting Guideline Requirements for the Reregistration of Chlorpyrifos
REQUIREMENT
                                                             USE    CITATION(S)
                                                             PATT
                       Amphibian Toxicity                     A,B
                       Simulated Freshwater Field Studies       A,B
                       Freshwater Microcosm/Fish Toxicity      A,B

       TOXICOLOGY
870.1100      81-1      Acute Oral Toxicity-Rat                 A,B
             81-2      Acute Dermal Toxicity-Rabbit/Rat        A,B
                       Acute Inhalation Toxicity-Rat            A,B
                       Primary Eye Irritation-Rabbit            A,B
                       Primary Skin Irritation                  A,B
                       Dermal Sensitization                    A,B
                       Acute Delayed Neurotoxicity - Hen        A,B
                       Special Acute Rat Neurotoxic Esterase     A,B
                       Acute Pharmacokinetic Study - rat        A,B
                       Cognitive Rat Study                     A,B
                       90-Day Feeding - Rodent                A,B
                       90-Day Feeding - Non-rodent             A,B
                       21-Day Dermal - Rabbit/Rat             A,B
                       90-Day Inhalation-Rat                  A,B
                       13-Week Rat Neurotoxicity study         A,B
                       Chronic Feeding Toxicity - Rodent        A,B
870.1200
870.1300
870.2400
870.2500
870.2600
870.6100
81-3
81-4
81-5
81-6
81-7
870.3100
870.3150
870.3200
870.3465

870.4100
82-1A
82-1B
82-2
82-4
82-8
83-1A
                                                                    44692201, 45506303
                                                                    00024400,00095366, 00154717, 44823801
                                                                    00092775,00095128,00095370,41205403,43216401, 43216402,
                                                                    43216403,44692101,44585405
44209101,42495404,44884301
44209102
00146507,40055001
44209103
44209104
44209105
00097144,00405106
44273901
44648102
44020901
40436406,40952801
42172801
40972801,41340201
40013901,40166501,40908401
42929801,43426601
40952802,42172802,42534201
                                                               151

-------
                                                       APPENDIX B
                       Data Supporting Guideline Requirements for the Reregistration of Chlorpyrifos
REQUIREMENT
                                                              USE    CITATION(S)
                                                             PATT
870.4100
              83-1B     Chronic Feeding Toxicity - Non-Rodent     A,B   00064933,00146519,45360101
                       Oncogenicity - Rat
                       Oncogenicity - Mouse
                       Developmental Tox. - Rat
                       Developmental Toxicity - Rabbit
                       2-Generation Repro. - Rat
                       Developmental Neurotoxicity - rat
                       Mutagenicity Studies

                       General Metabolism
                       6-Week Dietary Study
                       Acetylcholinesterase Inhibition in the
                       Dog
                       Human data
       OCCUPATIONAL/RESIDENTIAL EXPOSURE
875.2100       132-1A   Foliar Residue Dissipation
870.4200
870.4200
870.3700
870.3700
870.3800
870.6200
870.5140
870.5375
83-2A
83-2B
83-3A
83-3B
83-4
83-6
84-2A
84-2B
870.7485
85-1
875.2200
              132-1B    Soil Residue Dissipation
A,B    40952802,42172802
A,B    00054352, 00142902,42534201
A,B    00095268, 00130400,40436407
A,B    40436408
A,B    00029064, 00064934,41930301
A,B    44556901, 44648101, 45360102
A,B    00152683, 00152684, 00157058, 00157057, 40057201 40436401,
       40436409,40436411,41340203,44533401
A,B    40458901, 44648102,44810701
A,B    45467301,45467302
                                                              A,B   42008401, 42031701, 44035001, 44811002,44889501,45098001,
                                                                    45144101,45195701,45195702,45195703,45195704,45195705
                                                A,B    42974501, 42994401, 43062701, 43062702, 44748101, 44748102, data
                                                       gap for ornamentals grown in greenhouses, biological monitoring
                                                       data to develop transfer coefficientf for various greenhouse/nursery
                                                       activities
                                                A,B    41540202,42974501, data gap for reentry into treated areas with soil
                                                       incorporated/directed applications
                                                               152

-------
                                                        APPENDIX B
                       Data Supporting Guideline Requirements for the Reregistration of Chlorpyrifos
REQUIREMENT
                                                       USE    CITATION(S)
                                                       PATT
875.2400
875.2500
875.1100
      133-3     Dermal Passive Dosimetry Exposure
      133-4     Inhalation Passive Dosimetry Exposure
      231
Estimation of Dermal Exposure at
Outdoor Sites
875.1300
      232
Estimation of Inhalation Exposure at
Outdoor Sites
              233
              234
                Estimation of Dermal Exposure at
                Indoor Sites

                Estimation of Inhalation Exposure at
                Indoor Sites
None

835.2120

835.2240

835.2410

835.2370
ENVIRONMENTAL FATE

      160-5     Chemical Identity

      161-1

      161-2

      161-3
      161-4
Hydrolysis

Photodegradation - Water

Photodegradation - Soil

Photodegradation - Air
A,B    42974501, 42994401, 42994401,43027901,43042002,43138101,
       43138102,44483501,44739302,

A,B    42974501,42994401,42994401,43027901,43042002,43138101,
       43138102,44483501,44739302,

A,B    40026001, 43013501, 43013502, 43013503, 43042001 44167101,
       44444801, 44729401,44729402,44739301,44589001,data gap for
       seed treatment uses, dip applications (preplant peach), mixing
       wettable powders for aerial/chemigation application, loading and
       applying granulars for aerial applications, groundboom application,
       and backpack spray applications

A,B    40026001, 43013501, 44167101, 44444801,44729401,44729402,
       44739301,44589001, data gap for seed treatment uses, dip
       applications (preplant peach), mixing wettable powders for
       aerial/chemigation application, loading and applying granulars for
       aerial applications , groundboom application, and backpack spray
       applications

A,B    40094001,44458201,42887201, Data gap for treated wood in
       residential structures.

A,B    40094001,44458201,43963701, Data gap for treated wood in
       residential structures.
A,B    00146506,00146508

A,B    00155577

A,B    41747206,40026101

A,B    42495403

A,B    40234801, waived
                                                                153

-------
                                                       APPENDIX B
                       Data Supporting Guideline Requirements for the Reregistration of Chlorpyrifos
REQUIREMENT
                                                USE    CITATION(S)
                                               PATT
835.4100       162-1     Aerobic Soil Metabolism

835.4200       162-2     Anaerobic Soil Metabolism

835.4400       162-3     Anaerobic Aquatic Metabolism

835.4300       162-4     Aerobic Aquatic Metabolism

835.1240       163-1     Leaching/Adsorption/
                       Desorption

835.6100       164-1     Terrestrial Field Dissipation


835.1850       165-1     Confined Rotational Crop

None          165-4     Bioaccumulation in Fish

RESIDUE CHEMISTRY

None          171-2     Chemical Identity

860.1300       171-4A   Nature of Residue - Plants
860.1300

860.1340
171-4B    Nature of Residue- Livestock

171-      Residue Analytical Method - Plants and
4C+D     Animals
860.1380
171-4E    Storage Stability
                                                A,B    00025619,42144911,42144912

                                                A,B    00025619

                                                A,B    waived

                                                A,B    44083401, waived

                                                A,B    00155636, 00155637, 40050401, 41892801,41892802,42493901


                                                A,B    40059001,40395201,42874702,42874703,42874704,42924801,
                                                       42924802,

                                                A,B    43210801

                                                A,B    40056401,42495405,42495406
00146508

00066725,00072657,00072660,00157541,00157542,
40638801,40638802,41829007

00154734,00161743, 40638802

00037455,00037457,00037458,00039642,00039643,
00058089,00084330,00084331,00095179,00095201,
00095251,00095383,00095387,00095436,00134720,
00148881,00155578,00155579,00155580,00157713,
00158567,00158568,00158569,00162109,00164187,
40131302,40288501

00034031,00044555,00051798,00077120, 00095227,
00095374,00101566,00116675,00134720,00162109
A,B
A,B

A,B
A,B





A,B

00146506,
00066724,
00157543,
00077055,
00034031,
00051801,
00095216,
00141725,
00158566,
40131301,
00033586,
00095260,
                                                               154

-------
                                                       APPENDIX B
                       Data Supporting Guideline Requirements for the Reregistration of Chlorpyrifos
REQUIREMENT
 USE   CITATION(S)
PATT
860.1480
860.1500
171-4J
171-4K
Magnitude of Residues -
Meat/Milk/Poultry/Egg
Magnitude of Residue in Plants
A,B
A,B
00058087, 00095179, 00095438, 42542701
Radish, fresh - 0095259
                        (Root and Tuber Vegetables Group)
860.1500       171-4K   Mag. of Res.-Plants
                       (Leaves of Root and Tuber Veg. Group)

860.1500       171-4K   Mag. of Res.-Plants
                       (Bulb Veg. Group)

860.1500       171-4K   Mag. of Res.-Plants
                       (Brassica Leafy Vegetables group)
860.1500       171-4K   Mag. of Res.-Plants
                       Legume Vegetables (succulent or dried)
                       Group

860.1500       171-4K   Mag. of Res.-Plants
                       (Foliage of Legume Vegetables Group)
860.1500       171-4K   Mag. of Res.-Plants
                       [Fruiting Vegetables (except cucurbits)
                       Group]
       Rutabagas, root - 0095259
       Sugar beets, root - 00039641,00101566
       Sweet potatoes, root - 00095227
       Turnip, root - 0095259

A,B   Sugar beets, tops - 00039641,00101566
       Turnip, tops - 00095259

A,B   Leeks - 00157909
       Onions, dry bulb(only) - 00154019,42649001

A,B   Broccoli - 00095273, 00155580, 00158566
       Brussels sprouts - 00095273,00158566
       Cabbage - 00095273,00155580,00158566
       Cabbage, Chinese - 00095273
       Cauliflower - 00095273,00158566

A,B   Beans, lima - 42245907
       Beans, snap - 42245907
       Soybeans - 00095270, data gap for aspirated grain fractions

A,B   Beans, vines - 00095264,42245907
       Beans, lima, vines - 00095264,42245907
       Beans, snap, vines - 42245907
       Peas, vines - 00095264
       Soybeans, forage - 00095270

A,B   Tomatoes -00095251,00131864, (tomato tolerance being revoked)
                                                               155

-------
                                                       APPENDIX B
                       Data Supporting Guideline Requirements for the Reregistration of Chlorpyrifos
REQUIREMENT
                                      USE
                                      PATT
       CITATION(S)
860.1500       171-4K
860.1500       171-4K
860.1500       171-4K
860.1500       171-4K
Mag. of Res.- Plants
(Cucurbit Veg Group)

Mag. of Res.- Plants
Citrus Fruits Group

Mag. of Res.- Plants
(Pome Fruits Group)

Mag. of Res.- Plants
(Stone Fruits Group)
       Cucumbers - 00095264
       Pumpkins - 00095264
A,B


A,B    00084326,00095260
A,B    Apples - 00044555,00088978,00095264
       Pears - 00044555,43445601

A,B    Cherries - 00044555,00077120, data gap
       Nectarines - 00044555,00095179
       Peaches - 00044555,00095179
       Plums (fresh prunes) - 00044555
860.1500       171-4K   Mag. of Res.-Plants
                       (Small Fruits and Berries Group)
860.1500       171-4K   Mag. of Res.-Plants
                       (Tree Nuts Group)

860.1500       171-4K   Mag. of Res.-Plants
                       Cereal Grains Group
                                      A,B    Bluberry - 00164187
                                             Caneberries - PP#7E3557
                                             Cranberries - 00108813
                                             Grapes - 00085785, 00126713, 00134499, PP#3F02872/3H05393
                                             Strawberries - 00095271,40131302

                                      A,B    00132786, 00044555, 00116675,41424401
                                      A,B    Corn, field, grain - 00070509
                                             Corn, sweet (K+CWHR) - 00095216,42245904
                                             Sorghum, grain (milo) - 00046785,00095249,42245905, data gap for
                                             aspirated grain fractions
                                             Wheat, grain - data gap for aspirated grain fractions
                                                               156

-------
                                                      APPENDIX B
                      Data Supporting Guideline Requirements for the Reregistration of Chlorpyrifos
REQUIREMENT
                                                USE   CITATION(S)
                                               PATT
860.1500
171-4K
860.1500
860.1500
171-4K
171-4K
860.1500
171-4K
Mag. of Res.- Plants
(Forage, Fodder, and Straw of Cereal
Grains Group)
Mag. of Res.- Plants
(Non-grass Animal Feeds (forage,
fodder, straw, and hay) Group)
Mag. of Res.- Plants
(Miscellaneous Commodities)
Mag. of Res.- Plants
(Crops Grown Solely for Seed)
A,B    Corn, Fodder - 00070509,00078962, data gap
       Corn, Forage - 00070509,00078962, data gap
       Sorghum, Fodder (milo) - 00046785,00158569, Sorghum, Forage
       (milo) - 00046785,00158569, Wheat, forage -
       PP#3F2947/FAP#3H5411, data gap for aspirated grain fractions
       Wheat, straw - PP#3F2947/FAP#3H5411, data gap for aspirated
       grain fractions

A,B    Alfalfa, forage - 00125686,00158567,00158568,41739001
       Alfalfa, hay - 00125686,00158567,00158568,41739001


A,B    Asparagus - 00094088
       Bananas - 00125686
       Cherimoya - PP#7E3536
       Cottonseed - 00095373,40131303, data gap for cotton gin by-
       products
       Dates - 00162109
       Feijoa (pineapple guava)  - PP#7E3536
       Figs - 00098580
       Kiwifruits - 00115260
       Mint - 00034031
       Mushrooms - 00129295
       Peanuts - 00025942,00083840,00095263
       Sapote - PP#7E3536
       Sugarcane - 42645401
       Sunflower - 00084845, 42245906, 43181401
       Tobacco - 40265201

A,B    Clover forage, seed and hay - data gap
       Grass forage  and hay - data gap
                                                              157

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                                                       APPENDIX B
                      Data Supporting Guideline Requirements for the Reregistration of Chlorpyrifos
REQUIREMENT
                                                USE    CITATION(S)
                                               PATT
860.1520
171-4L
860.1460      171-41


OTHER

810.1000      90-1


810.1000      90-1


810.1000      90-1


810.1000      90-1
Magnitude of the Residues in Processed
Food/Feed
          Magnitude of Residue in Food Handling
          Establishments
          Usage Data for hydraulic handheld
          equipment

          Usage Data for high pressure hand-
          wand equipment

          Usage Data for groundboom
          applications to sodfarms

          Usage Data for greenhouse activities
A,B    Alfalfa - 00125686, 00158567, 00158568
       Apples - 00044555,00088978,00095264
       Citrus - 00084326
       Corn, field - 00084266,42649002
       Corn, sweet - 42649002
       Cottonseed - 00037455
       Grapes - 00085785,00126713,00134499
       Mint - 00034031
       Peanuts - 00025942,00083840,00095263
       Plums - 00044555
       Sorghum - 00046785, 00095249
       Soybeans - 00095270
       Sugar beet - 00039641,00101566
       Sugarcane - 42645401
       Sunflower - 00084846, 42245906, 43181401
       Tomatoes - 00095251
       Wheat - PP#3F2947/FAP#3H5411

A,B    00090562,00090563
                                      A,B    Data gap for usage data of amount of ai handled per day, per season
                                             and types of equipment.

                                      A,B    Data gap for usage data of amount of ai handled per day, per season
                                             and types of equipment.

                                      A,B    Data gap for usage data of acres treated per day at the 3 Ib/A rate
                                             on sodfarms.

                                      A,B    use pattern information, timing of application relative to post-
                                             application activities
                                                               158

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                                                   APPENDIX B
                     Data Supporting Guideline Requirements for the Reregistration of Chlorpyrifos
REQUIREMENT
 USE    CITATION(S)
PATT
             201-1     Droplet Size Spectrum
             202-1     Drift Field Evaluation
                      Incident data
A,B    43760606, 43760607, 43786902
A,B    41887501,43786903
A,B    43798001,44039901,44186301,44245801
                                                           159

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160

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Appendix C.Technical Support Documents
                 161

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Appendix C.  TECHNICAL SUPPORT DOCUMENTS

      Additional documentation in support of this RED is maintained in the OPP docket, located
in Room 119, Crystal Mall #2,  1921 Jefferson Davis Highway, Arlington, VA. It is open Monday
through Friday, excluding legal holidays, from 8:30 am to 4 pm.

      The docket initially contained preliminary risk assessments and related documents as of
August 10, 1998.  Sixty days later the first public comment period closed. The EPA then
considered comments, revised the risk assessment, and added the formal "Response to Comments"
document and the revised risk assessment to the docket on June 16,  1999.

      All documents, in hard copy form, may be viewed in the OPP docket room or downloaded
or viewed via the Internet at the following site:

             www.epa.gov/pesticides/op

These documents include:

HED Documents:

1. David Soderberg (USEPA/OPPTS/OPP/HED).  Acute Dietary Risk Assessment for
Chlorpyrifos, Revised after Public Comments. June 22, 2000.

2. David Soderberg (USEPA/OPPTS/OPP/HED).  Chronic Dietary Exposure Assessment for
Chlorpyrifos RED with Updated Values for Anticipated Residues, Revised after Public Comments.
June 22, 2000.

3. Steven A. Knizner (USEPA/OPPTS/OPP/HED). Chlorpyrifos - Revised Product and Residue
Chemistry Chapters of the HED Chapter of the RED. June 20, 2000.

4. Tim Leighton (USEPA/OPPTS/OPP/HED).  Agricultural and Occupational Exposure
Assessment and Recommendations  for the RED Document for Chlorpyrifos.  June 19, 2000.
      EFED Document:

1.  William Rabert (USEPA/OPPTS/OPP/EFED).  EFED Review of Lorsban-4E, Lock-On, and
Lorsban 15G Label Changes. July 31, 2001.
                                         162

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Appendix D.  Citations Considered to be Part of the Data Base Supporting the
             Interim Reregistration Decision (Bibliography)
                                  163

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       Appendix D.  CITATIONS CONSIDERED TO BE PART OF THE DATA BASE
                    SUPPORTING THE INTERIM REREGISTRATION DECISION
                    (BIBLIOGRAPHY)

GUIDE TO APPENDIX D

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 Reregi strati on 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 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 six-digit
       "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


                                          164

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       from the evidence contained in the document. When the date appears as (1999), 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.

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.
                                    165

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                             Chlorpyrifos Bibliography

Barone, S., C. Lau, V.C. Moser, P.M. Phillips, K.L. McDaniel, D. Hunter, R. Marshall, P.
Kodavanti, F. Dern-Yellin, and S. Padilla. (1997) Developmental effects of gestational exposure to
chlorpyrifos in the rat [abstract 1301]. Toxicologist 36(1):256.

Bradman MA, et al. 1997. Pesticide exposures to children from California's Central Valley:
results of a pilot study.  J. Expos. Anal. Environ. Epidem. Vol 7 No. 2, pp. 217-234.

Brzak, K.A., Harms, D.W., Bartels, M.J., and Nolan, RJ.  1998. Determination of Chlorpyrifos,
Chlorpyrifos-oxon and 3,5,6-trichloro-2-pyridinol in rat and human blood.  J. Anal Toxicol.
22:203-230.

Capodicasa, E., Scapellato, M.L., Moretto, A., Caroldi S., and Lotti, M. 1991. Chlorpyrifos-
induced delayed polyneuropathy.  Arch Toxicol. 65:150-155.

Campbell, C.G., Seidler, FJ, and Slotkin, T.A.  (1997). Chlorpyrifos interferes with cell
development in rat brain regions (Brain Res. Bull 43(2): 179-189.

Chakraborti, T.K., J.D. Farrar, and C.N. Pope. (1993) Comparative neurochemical and
neurobehavioral effects of repeated chlorpyrifos exposures in young and adult rats. Pharmacology
Biochemistry and Behavior 46:219-224.

Chanda, S.M., J. Chaudhuri, T. Chakraborti, and C.  Pope. (1993) Persistent fetal brain
cholinesterase inhibition induced by a single maternal dose of chlorpyrifos [abstract 257].
Toxicologist 13:88.

Chanda, S.M., P. Harp,  J.  Liu, and C.N. Pope. (1995) Comparative developmental and maternal
neurotoxicity following acute gestational exposure to chlorpyrifos in rats. Journal of Toxicology
and Environmental Health 44:189-202.

Chanda, S.M., S.R. Mortensen, S. Barone, V.C. Moser, and S. Padilla. (1997) Developmental
profiles of two organophosphate detoxifying enzymes: carboxylesterase and A-esterase [abstract
1757]. Toxicologist 36(l):346.

Chanda S.M. and  C.N. Pope. (1996) Neurochemical and neurobehavioral effects of repeated
gestational exposure to chlorpyrifos in maternal and developing rats. Pharmacology Biochemistry
and Behavior 5 3 (4): 771-776.

Costa LG, Li WF, Richter RJ,  Shih DM, Lusis A, and Furlong CE. 1999.  The role of paraoxonase
(PON1) in the detoxication of organophosphates and its human polymorphism.  Chemico-
Biological Interactions 119-120: 429-438
                                           166

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                             Chlorpyrifos Bibliography

Dam K, Garcia SJ, Seidler FJ, Slotkin TA (1999a) Neonatal chlorpyrifos exposure alters synaptic
development and neuronal activity in cholinergic and catecholaminergic pathways. Developmental
Brain Res. 116:9-20.

Dam K; Seidler FJ; Slotkin TA (1999b) Chlorpyrifos releases norepinephrine from adult and
neonatal rat brain synaptosomes. Brain Res Dev Brain Res, 118(1-2): 129-33.

Das KP, Barone S (1999) Neuronal differentiation in PC 12 cells is inhibited by chlorpyrifos and
its metabolites: Is acetylcholinesterase inhibition the site of action? Toxicol. Applied Pharmacol.
160:217-230.

Davies HG, Richter RJ, Keifer M, Broomfield CA, Sowalla J, and Furlong CE. 1996. The effect
of the human serum paraoxonase polymorphism is reverse with diazoxon, soman and sarin. Nat
Genet. Nov 14(3):334-6.

Furlong, CE., Li WF., Costa, LG., Richter RJ., Shih DM, and Lusis AJ.  1998 Genetically
determined susceptibility to organophosphorus insecticides and nerve agents: developing a mouse
model for the human PON 1  polymorphism.  Neurotoxicology. Aug-Oct: 19(4-5):645-60

GAO. 2000. Improvements needed to ensure the safety of farm workers and their children.  GAO
Report Number RCED-00-40.

Johnson, D.E., Seidler F.J., and Slotkin, T.A. 1998. Early Biochemical Detection of Delayed
Neurotoxicity Resulting from Developmental Exposure to Chlorpyrifos. Brain Research Bulletin.
45(2): 143-147.

Lassiter, T.L., S. Padilla, and S. Barone. (1997) Effects of gestational exposure to chlorpyrifos on
the developmental profiles of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE)
activity  in the rat brain [abstract 1313].  Toxicologist 36(1):259.

Lassiter, T.L., D. Hunter, R. Marshall, S. Mortensen, S. Chanda, K. Das, and S. Padilla. (1997)
The fetal brain appears to be protected from late gestational exposure to chlorpyrifos.
Platform/Poster submission, Neurobehavioral Teratology Society Meeting.

Lassiter TL, Padilla S, Mortensen SR, Chanda SM, Moser VC, Barone S (1998) Gestational
exposure to chlorpyrifos: Apparent protection of the fetus?  Toxicol. Applied Pharmacol. 152:  56-
65.

Li WF, Costa LG, Furlong CE. 1993. Serum paraoxonase status:  a major factor in determining
resistence to organophosphates. J Toxicol Environ Health. Oct-Nov: 40(2-3):337-46.
Leighton TM, Nielsen AP. 1995.  The U.S.  Environmental Protection Agency, Health Canada,
and National Agricultural Chemicals Association, Pesticide Handlers Exposure Database.  Appl.
Occup. Environ. Hyg. 10(4).
                                           167

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                             Chlorpyrifos Bibliography

Mortensen, S.R., Hooper MJ. S. Padilla. 1998. Rat brain acetylcholinesterase activity:
developmental profile and maturational sensitivity to carbamate and organophosphorus inhibitors.
Toxicology. 125:13-19.

Mortensen, S.R., S.M. Chanda, MJ. Hooper, and S. Padilla. (1997, draft) Maturational differences
in chlorpyrifos-oxonase activity may contribute to age-related sensitivity to chlorpyrifos.

Mortensen, S.R., MJ. Hooper, and S. Padilla. (1997, draft) Developmental profiles and
maturational sensitivity of rat brain acetylcholinesterase activity.

Moser, V.C. and S. Padilla. 1998. Age- and gender-related differences in the time-course of
behavioral and biochemical effects produced by oral chlorpyrifos in rats. Toxicology and Applied
Pharmacology. 149:107-119.

Moser, V.C., Chanda, S.M., Mortensen S.R., and Padilla, S. 1998. Age- and Gender-Related
Differences in Sensitivity to Chlorpyrifos in the Rat Reflect Developmental Profiles of Esterase
Activities. Toxicological Sciences. 46:211-222.

National Agricultural Pesticide Impact Assessment Program (NAPIAP).  1996. Biologic and
economic assessment of pest management in the United States greenhouse  and nursery industry.
NAPIAP Report Number l-CA-96.

Nigg NN and Knaak JB. 2000. Blood cholinesterases as human biomarkers of organophosphorus
pesticide exposure. Rev Environ Contam Toxicol 163:29-112.

Nolan R.J., Rick D.L., Freshour M.L., and Saunders J.H. 1982. Chlorpyrifos: Pharmacokinetics
in human volunteers following single oral and dermal doses. The Dow Chemical Co. Biomedical
Medical Research Lab. Toxicology Research Lab. Midland MI. Accession No. 249203.

Padilla S., Wilson, V.Z., and  Bushnell, P J.  (1994).  Studies on the correlation between blood
cholinesterase inhibition and  "Target Tissue" inhibition in pesticide-treated rats.  Toxicology
92; 11-25.

Phillips, P.M., K.L. McDaniel, T.L. Lassiter, S. Barone, and V.C. Moser. (1997) Behavioral
effects of gestational exposure to chlorpyrifos in rats [abstract 1300]. Toxicologist 36(1):256.

Pope, C.N., T.K. Chakraborti, M.L. Chapman, J.D. Farrar and D. Arthun. (1991) Comparison of in
vivo cholinesterase inhibition in neonatal and adult rats by three organophosphorothioate
insecticides. Toxicology 68:51-61.

Pope, C.N. and T.K. Chakraborti. (1992) Dose-related inhibition of brain and plasma
cholinesterase in neonatal and adult rats following sublethal organophosphate exposures.
Toxicology 73:35-43.
                                           168

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                             Chlorpyrifos Bibliography

Pope, C.N, Chakraborti, T.K., Chapman, M.L and Farrar, J.D. (1992). Long-Term neuro -
behavioral and behavioral effects induced by acute chlorpyrifos treatment (1992) Pharm. Biochem.
Behav. 42:251-256

Pope, C.N and Liu, J (1997).  Age-Related Differences in Sensitivity to Organophosphorous
Pesticides. Environmental Toxicol. AndPharmacol.  4;309-314.

Richardson R.J., Moore T.B., Kayyali, U.S., and Randall J.C. 1993. Chlorpyrifos: Assessment of
Potential for Delayed Neurotoxicity by Repeated Dosing in Adult Hens with Monitoring of Brain
Acetylcholinesterase, Brain and Lymphocyte Neurotoxic Esterase, and Plasma
Butyrylcholinesterase Activities. Fund. Applied. Toxicology. 21:89-96.

Roy TS, Andrews JE, Seidler FJ, Slotkin TA (1998) Chlorpyrifos elicits mitotic abnormalities and
apoptosis in neuroepithelium of cultured rat embryos. Teratology 58:62-68.

Shih DM, Gu L, Xia YR, Navab M, Li WF, Kama S, Castellani LW, Furlong CE, Costa LG,
Fogelman AM and Lusis AJ.  1998. Mice Lacking serum paraoxonase are susceptible to
organophosphate toxicity and atherosclerosis. Nature.  Jul 16: 394 (6690):284-7

Simcox NJ, Fenske RA, Wolz SA, Lee 1C, Kalman DA. 1995. Pesticides in household dust and
soil: exposure pathways for children of agricultural families.  Environ Health Perspect 103: 1126-
1134.

Slokin T.A.  1999. Developmental Cholinotoxicants: Nicotine and Chlorpyrifos.  Environmental
Health Perspectives. 107, Supplement 1, 71-80.

Song, X., Seidler, F.J., Saleh, J.L., Zhang, J. Padilla,  S., Slotkin T.A.  1997.  Cellular mechanisms
for developmental toxicity of chlorpyrifos: targeting the adenylyl cyclase signaling cascade.
Toxciol Appl. Pharmacol. 145:158-174.

Stanton, M.E., W.R. Mundy, T. Ward, V. Dulchinos, and C.C. Barry. (1994) Time-dependent
effects of acute chlorpyrifos administration on spatial delayed alternation and cholinergic
neurochemistry in weanling rats. NeuroToxicology 15(1):201-208.

Tang J, Carr RL, Chambers JE (1999) Changes in rat brain cholinesterase activity and muscarinic
receptor density during and after repeated oral exposure to chlorpyrifos in early postnatal
development. Toxicological Sciences 51:265-272.

USD A. 1979. Planting and harvesting data for U.S.  vegetables.  USDA Handbook 507.

U.S. EPA 1987. Pesticide Assessment Guidelines, Subdivision U: Applicator Exposure
Monitoring. (Currently referred to as Series 875 Group A). Office of Pesticide Programs,
Washington, DC.  EPA/540/9-87-127.
                                           169

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                             Chlorpyrifos Bibliography

U.S. EPA 1992a. Guidelines for exposure assessment.  Federal Register Notice.  Vol. 57. No. 104,
pp. 22888-22938.

U.S. EPA 1992b. Dermal exposure assessment: principles and applications. Office of Health and
Environmental Assessment, Washington, DC. EPA/600/8-9/01 IF.

U.S. EPA and Health Canada. 1995a.  PHED Evaluation Guidance.  Prepared by Versar, Inc.
March 15, 1995.

U.S. EPA, Health Canada, American Crop Protection Association. 1995b.  PHED: The Pesticide
Handlers Exposure Database,  Reference Manual Version 1.1. Prepared by Versar, Inc. February
1995.

Whitney, K.D., Seidler, F.J., and Slotkin, T.A (1995).  Developmental Neurotoxicity of
Chlorpyrifos Cellular Mechanism.Toxicol. AndPharmacoll34:53-62

Zheng, Q., Olivier K., Won Y., and Pope C.  1999. Comparative Cholinergic Neurotoxicity of
Oral Chlorpyrifos Exposures in Neonatal and Adult Rats. Abstract and Poster Presentation.
presented at the 38th Annual Society of Toxicology Meeting in New Orleans, March 14-18.  The
Toxicologist Vol 48, No.l-S, #874. March 1999.

Zheng Q, Olivier K, Won YK, Pope CN (2000) Comparative cholinergic neurotoxicity of oral
Chlorpyrifos exposures in preweanling and adult rats. Accepted for Publication.
Product Chemistry MRID References

00146506    Dow Chemical U.S.A. (1985) Product Chemistry: Dursban F Insecticidal Chemical.
             Unpublished compilation.  63 p.

00146508    Dow Chemical U.S.A. (1985) Product Chemistry: Dursban R Insecticidal
             Chemical. Unpublished compilation.  34 p.

40105301    Dow Chemical Co. (1987) Dursban F Insecticidal Chemical Product Identity and
             Composition. Unpublished compilation. 29 p.

40144101    Dow Chemical U.S.A. (1987) Dursban F Insecticidal Chemical Analysis and
             Certification of Product Ingredients. Unpublished compilation. 74 p.

40411301    Dow Chemical Co. (1987) Dursban R Insecticidal Chemical: Product Identity and
             Composition. Unpublished study.  17 p.
                                          170

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                            Chlorpyrifos Bibliography

41653503     Hamburg, F. (1990) Determination of the Compatibility Characteristics of Dursban
             R: Lab Project No: 90014: GH-C2369.  Unpublished study by DowElanco. 11 p.

41747202     Hamburg, F. (1990) Determination of the Density of Dursban F Technical: Lab
             Project Number: GH-C 2405. Unpublished study prepared by DoeElanco. 10 p.

41747204     Hamburg, F. (1990) Storage Stability of Dursban R: Lab Project Number: GH-C
             2439. Unpublished study prepared by DowElanco.  10 p.

41747205     Hamburg, F. (1990) Determination of the Oxidizing or Reducing Action of Dursban
             F Technical: Lab Project No: GH-C 2422. Unpublished study by DowElanco. 10 p.

42495401     Jones-Jefferson, T.; Bischoff, R. (1992) Response to EPA Chlorpyrifos Generic
             Data Call-in dated September 18, 1991: Product Chemistry|: Lab Project Number:
             RFB-92. Unpublished study prepared by DowElanco. 6 p.

42495402     Jones-Jefferson, T. (1992) Density of Dursban Technical:  Lab Project Number:
             FOR92037. Unpublished study prepared by DowElanco.  lip.

42527201     Krause, R. (1988) Laboratory Immersion Compatibility Test Procedure for Testing
             with Metals, Rubbers, and Plastics: Lab Project Number: REK51688. Unpublished
             study prepared by DowElanco. 10 p.

42527203     Skelly, N. (1980) Analytical Method Validation Report for the Determination of
             Chlorpyrifos in Dursban Insecticide Formulations by Reversed-phase Liquid
             Chromatography: Lab Project Number: ML-AL-80-70511. Unpublished study
             prepared by DowElanco. 36 p.

42544901     Hermann, E. (1992) Batch Analysis of Dursban FM Insecticide for the Presence of
             2,3,7,8-Tetrachloro-l,4-Dioxino-2,3B-5,6B Dipyridine: Lab Project Number:
             DECO ML-AL 92-030221. Unpublished study by The Dow Chemical Co. 15 p.

42652601     Macdonald, I. (1985) The Determination of Physico-Chemical  Parameters of
             Chlorpyrifos: Lab Project Number: DWC 432/85579. Unpublished study prepared
             by Huntington Research Centre Ltd. 28 p.

43046602     Powers, J.; Beckrow, R. (1992) Explodability of Dursban R Insecticide AGR
             Sample 220406 by Drop Weight Tester: Lab Project Number: ML-AL 91-110098.
             Unpublished study prepared by The Dow Chemical  Co. 9 p.

43428701     Kinnunen, C. (1994) Series 63-14: Determination of Oxidation/Reducing Action of
             Dursban R: Lab Project No: FOR94049. Unpublished study by DowElanco.  10 p.
                                         171

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                            Chlorpyrifos Bibliography

43428702     Kinnunen, C. (1994) Series 63-16: Determination of Explodability of Dursban FM:
             Lab Project Number: FOR94010. Unpublished study by DowElanco. 8 p.

43633901     Krause, R.; Kinnunen, C. (1995) Storage Stability of Dursban FM: One Year
             Ambient Temperature Storage Study Results: Lab Project Number: FOR94009.
             Unpublished study prepared by DowElanco. 14 p.

45434001     Smith, A. (2001) Group A: Product Identity and Composition, Description of
             Materials Used to Produce the Product, Description of Production Process,
             Discussion of Formation of Impurities, Preliminary Analysis, and Enforcement
             Analytical Methods for Dursban F, Dursban FM, Dursban FE, Dursban FI, Lorsban
             F, or Lorsban Technical: Lab  Project Number: NAFST407: P97-057: DECO
             ML-AL 97-000023. Unpublished study by Dow AgroSciences LLC and The Dow
             Chemical Company. 448 p. (OPPTS 830.1550, 830.1600, 830.1620, 830.1670,
             830.1700, 830.1800, 830.1750}
Ecological Effects MRID References

00024400     Hurlbert, S.H.; Mulla, M.S.; Keith, J.O.; et al. (1970) Biological effects and
             persistence of Dursban in freshwater ponds. Journal of Economic Entomology
             63(l):43-52.  (Also In unpublished submission received Jul 19, 1978 under
             201-403; submitted by Shell Chemical Co., Washington, D.C.; CDL:234468-O)

00040602     Johansen, C.; Mayer, D.; Baird, C. (1973) Bee Research Investigations, 1973.
             (Incomplete, unpublished study received Oct 21, 1976 under 6F1696; prepared by
             Washington State Univ., Dept. of Entomology in cooperation with Alfalfa Seed
             Pest Management Project, submitted by E.I. du Pont de Nemours & Co., Inc.,
             Wilmington, Del.; CDL:095326-M)

00046951     Fink, R.; Beavers, J.B.; Brown, R. (1978) Final Report: One-Generation
             Reproduction Study-Bobwhite Quail: Project No. 103-177. (Unpublished study
             received Oct 15, 1980 under 464-448; prepared by Wildlife International, Ltd. and
             Washington College, submitted by Dow Chemical U.S.A., Midland, Mich.;
             CDL:243487-L)

00046952     Fink, R.; Beavers, J.B.; Brown, R. (1978) Final Report: One-Generation
             Reproduction Study—Mallard Duck: Project No. 103-178. (Unpublished study
             received Oct 15, 1980 under 464-448; prepared by Wildlife International, Ltd. and
             Washington College, submitted by Dow Chemical U.S.A., Midland, Mich.;
             CDL:243487-M)
                                         172

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                            Chlorpyrifos Bibliography

00046953     Fink, R. (1977) Final Report: Eight-Week Feeding Study-Mallard Duck: Project
             No. 103-176. (Unpublished study received Oct 15, 1980 under 464-448; prepared
             by Wildlife International, Ltd., submitted by Dow Chemical U.S.A., Midland,
             Mich.; CDL:243487-N)

00046954     Fink, R.; Beavers, J.B.; Brown, R. (1978) Final Report: Eight-Day Dietary
             LC50-Mallard Duck: Project No. 103-180.  (Unpublished study received Oct 15,
             1980 under 464-448; prepared by Wildlife International, Ltd. and Washington
             College, submitted by Dow Chemical U.S.A., Midland, Mich.; CDL:243487-O)

00046955     Fink, R.; Beavers, J.B.; Brown, R. (1978) Final Report: Eight-Day Dietary
             LC50-Bobwhite Quail: Project No. 103-179. (Unpublished study received Oct 15,
             1980 under 464-448; prepared by Wildlife International, Ltd. and Washington
             College, submitted by Dow Chemical U.S.A., Midland, Mich.; CDL:243487-P)

00046958     Fink, R.; Beavers, J.B.; Brown, R. (1978) Final Report: Eleven-Day Toxicant 2 X
             LC50, with Five-Day Half-Life, Decreasing Concentrations—Mallard Duck: Project
             No. 103-183. (Unpublished study received Oct 15, 1980 under 464-448; prepared
             by Wildlife Inter national, Ltd. and Washington College, submitted by Dow
             Chemical U.S.A., Midland, Mich.; CDL:243487-S)

00060632     Johansen, C.; Eves, J. (1967) Bee Research Investigations, 1967: Report No.  21866.
             (Unpublished study received Mar 27, 1974 under 4F1485; prepared by Washington
             State Univ., submitted by Chemagro Corp., Kansas City, Mo.; CDL:092011-M)

00078524     Thompson, A.R. (1971) Effects of nine insecticides on the numbers and biomass of
             earthworms in pasture. Bulletin of Environmental Contamination & Toxicology
             5(6):577-586.  (Submitter report no. 31421; also~In~unpublished submission
             received July 31, 1972 under 3125-213; submitted by Mobay Chemical Corp.,
             Kansas City, Mo.; CDL: 120480-AW)

00092775     Davey, R.B.; Meisch, M.V.; Carter, F.L. (1976) Toxicity of five ricefield pesticides
             to the mosquitofish, Gambusia affmis, and green sunfish, Lepomis cyanellus, under
             laboratory and field conditions in Arkansas.  Environmental Entomology 5(6):
             1053-1056. (Also In unpublished submission received Mar 30, 1977 under
             279-2712; submitted by FMC Corp., Philadelphia, Pa.; CDL:229241-Q)

00095007     Stevenson, G.T. (1965) A Gamebird Toxicology Study—Acute Dietary Feeding of
             Dursban to Wild Type Mallard Ducklings.  (Unpublished study received Jan  11,
             1966 under 464-343; by Dow Chemical U.S.A., Midland, Mich.; CDL:003570-F)
                                         173

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                            Chlorpyrifos Bibliography

00095013     Alexander, H.C.; Batchelder, T.L. (1965) Results of a Study on the Acute Toxicity
             of Dursban (R) to Three Species of Fish. (Unpublished study received Jan 11, 1966
             under 464-343; by Dow Chemical U.S.A., Midland, Mich.; CDL:003570-L)

00095114     Kenaga, E.E. (1968) Simulated Wildlife-environmental Effects with Dursban
             Insecticide Using Laboratory Rabbits and Ducks in Small Scale Field Tests.
             (Unpublished study received Aug 14, 1970 under 464-343; submitted by Dow
             Chemical U.S.A., Midland, Mich.; CDL:050843-I)

00095123     Stevenson, G.T. (1965) A Game Bird Toxicology Study—Acute Dietary Feeding of
             Dursban to Bobwhite Quail: Ref. No. 3-1197-23. (Unpublished study received Dec
             18, 1967 under 464-368; submitted by Dow Chemical U.S.A., Midland, Mich.;
             CDL:050916-G)

00095125     Ferguson, D.E.; Gardner, D.T.; Lindley, A.L. (1966) Toxicity of Dursban to three
             species offish. Mosquito News 26(l):80-82. (Also In unpublished submission
             received Dec 18, 1967 under 464-368; submitted by Dow Chemial U.S.A.,
             Midland, Mich.; CDL: 050916-Q)

00095128     Miller, W.O. (1966) Pond Treatment with Dursban For Bluegill Sunfish: Toxicity
             Studies. (Unpublished study received Dec  18, 1967 under 464-368; submitted by
             Dow Chemical U.S.A., Midland, Mich.; CDL:050916-U)

00095130     Ludwig, P.O.; McNeill, J.C., IV; Miller, W.O. (1967) Preliminary results obtained
             with Dursban in the biotic community.  Down to Earth 22(4):3-5.  (Also in
             unpublished submission received Dec 18, 1967 under 464-368; submitted by Dow
             Chemical U.S.A., Midland, Mich.; CDL:050916-W)

00095296     McCann, J.A. (1970) Dursban 25W Insecticide: Bluegill (Lepomis macrochirus):
             Test No. 273. (U.S. Fish and Wildlife Service, Pesticides Regulation Div., Animal
             Biology Laboratory; unpublished study; CDL:130360-A)

00095297     McCann, J.A. (1969) Dursban: Rainbow Trout (Salmogairdneri): Test No. 196.
             (U.S. Fish and Wildlife Service, Pesticides  Regulation Div., Animal Biology
             Laboratory; unpublished study; CDL:130361-A)

00095298     McCann, J.A. (1970) Dursban 25W Insecticide: Bluegill (Lepomis macrochirus):
             Test No. 274. (U.S. Fish and Wildlife Service, Pesticides Regulation Div., Animal
             Biology Laboratory; unpublished study; CDL:130360-B)

00095301     Ludwig, P.O.; Dishburger, H.J.; McNeill, J.C., IV; et al. (1968) Biological effects
             and persistence of Dursban(R) insecticide in a salt-marsh habitat. Journal of
             Economic Entomology 61(3): 626-633.  (Also in unpublished submission received
                                         174

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                            Chlorpyrifos Bibliography

             Jun 1, 1968 under unknown number.; submitted by Dow Chemical U.S.A.,
             Midland, Mich.; CDL:128666-A)

00095304     Shellenberger, I.E. (1971) Letter sent to Eugene E. Kanaga dated May 24, 1971:
             Toxicity and acceptance studies of granular Dowco-179 formulations with
             bobwhite quail—study: GSRI Project No. NC-428. (Unpublished study received
             Jun 28, 1971 under unknown admin, no.; prepared by Gulf South Research
             Institute, by Dow Chemical U.S.A., Midland, Mich.; CDL:132116-D)

00095305     Shellenberger, I.E. (1971) Letter sent to Eugene E. Kanaga dated May 24, 1971:
             Toxicity and acceptance studies of granular Dowco-179 formulations with
             bobwhite quail—study I: GSRI Project No. NC-428.  (Unpublished study received
             Jun 28, 1971 under unknown admin, no.; prepared by Gulf South Research
             Institute, submitted by Dow Chemical U.S.A., Midland, Mich.; CDL: 132116-F)

00095321     McCann, J.A. (1969) Dursban 6: Bluegill (Lepomis machrochirus): Test No. 163.
             (U.S. Agricultural Research Service,  Pesticides Regulation Div., Animal Biology
             Laboratory; unpublished study; CDL:131663-A)

00095338     Nelson, J.H.; Evans, E.S., Jr. (1973) Field Evaluation of the Larvicidal
             Effectiveness, Effects on Nontarget Species and Environmental Residues of a
             Slow-release Polymer Formulation of Chloryrifos: March-October 1973.  By U.S.
             Army Environmental Hygiene Agency, Entomological Sciences and Pesticide Div.,
             Aberdeen Proving Ground, Md.:  USAEHA.  (Entomological Special Study No.
             44-022-73/75; published study; CDL:220988-C)

00095363     Hansen, D.J.; Schimmel, S.C.; Keltner, J.M., Jr. (1973) Avoidance of pesticides by
             grass shrimp (Palaemonetes pugio). Bulletin of Environmental Contamination &
             Toxicology 9(3)129-133.  (Also In unpublished submission received Nov 10, 1976
             under 464-448; submitted by Dow Chemical U.S.A., Midland, Mich.; CDL:
             226828-C)

00095365     Hurlbert, S.H.; Mulla, M.S.; Willson, H.R. (1972) Effects of an organophosphorus
             insecticide on the phytoplankton, zooplankton, and insect populations of
             fresh-water ponds. Ecological Monographs 42(3):269-299. (Also In unpublished
             submission received Nov  10, 1976 under 464-448; submitted by Dow Chemical
             U.S.A., Midland, Mich.; CDL:226828-F)

00095366     Macek, K.J.; Walsh, D.F.; Hogan, J.W.; et al. (1972) Toxicity of the insecticide
             Dursban(R) to fish and  aquatic invertebrates in ponds. Transactions of the
             American Fisheries Society 101 (3):420-427.  (Also In unpublished submission
             received Nov 10, 1976 under 464-448; submitted by Dow Chemical U.S.A.,
             Midland, Mich.; CDL:226828-I)
                                         175

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                            Chlorpyrifos Bibliography

00095367    Marganian, V.M.; Wall, W.J., Jr. (1972) Dursban(R) and Diazinon residues in biota
             following treatment of intertidal plots on Cape Cod—1967-69. Pesticides
             Monitoring Journal 6(3): 160-165. (Available from: Superintendent of Documents,
             U.S. Government Printing Office, Washington, DC 20402; CDL:  226828-J)

00095368    Roberts, D.R.; Roberts, L.W.; Miller, T.A.; et al. (1973) Polymer formulations of
             mosquito larvicides: III. Effects of a polyethylene formulation of chlorpyrifos on
             non-target populations naturally infesting artificial field pools. Mosquito News
             33(2): 165-172. (Also In unpublished submission received Nov 10, 1976 under
             464-448; submitted by Dow Chemical U.S.A., Midland, Mich.; CDL:226828-K)

00095370    Washino, R.K.; Ahmed, W.; Linn, J.D.; et al. (1972) Rice field mosquito control
             studies with low volume Dursban(R) sprays in Colusa County, California: IV.
             Effects upon aquatic nontarget organisms. Mosquito News 32(4):531-537. (Also
             in unpublished submission received Nov 10, 1976 under 464-448; submitted by
             Dow Chemical U.S.A., Midland, Mich.; CDL:226828-P)

00095371    Thompson, A.R.; Sans, W.W. (1974) Effects of soil insecticides in southwestern
             Ontario on non-target invertebrates: Earthworms in pasture. Environmental
             Entomology 3(2):305-308. (Also In unpublished submission Nov 10, 1976 under
             464-448; submitted by Dow Chemical U.S.A., Midland, Mich.; CDL:226828-R)

00095446    Kenaga, E.E.; Fink, R.J.; Beavers, J.B. (1978) Dietary Toxicity Tests with Mallards
             Simulating Residue Decline of Chlorpyrifos and Avoidance of Treated Food.
             Summary of studies 236884-B, 236884-C and 236884-E.  (Unpublished study
             received Jan 29, 1979 under 464-343; prepared in cooperation with Wildlife
             International, Ltd., by Dow Chemical U.S.A., Midland, Mich.; CDL:236884-A)

00095449    Fink, R.; Beavers, J.B.; Brown, R. (1978) Final Report: Elevenday Toxicant 1 X
             LC50, with Five-day Half-life, Decreasing Concentrations—Mallard Ducks:
             Chlorpyrifos: Project No. 103-184. (Unpublished study received Jan 29, 1979
             under 464-343; prepared by Wildlife International, Ltd., and Washington College,
             submitted by Dow Chemical U.S.A., Midland, Mich.; CDL: 236884-D)

00102520    McCarty, W.M. (1977) Toxicity of Chlorpyrifos to Daphnids: Report ES-164.
             (Unpublished study received Feb  13, 1978 under 464-363; submitted by Dow
             Chemical U.S.A., Midland, Mich.; CDL:232910-A)

00102758    Hansen, D. (1969) Avoidance of pesticides by untrained sheepshead minnows.
             Trans. Amer. Fish. Soc. 98(3):426-429. (Also In unpublished submission received
             Jan 5, 1972 under 2E1221; submitted by U.S. Dept.  of the Army, Washington, DC;
             CDL:097882-X)
                                          176

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00104696    Miller, W.O. (1966) The Effects of an Aerial Application of Dursban on the Fauna
             on a Coastal Island and in Associated Marsh Areas. (Unpublished study, Apr 29,
             1968 under 464-368; by Dow Chemical U.S.A., Midland, Mich.; CDL:003574-D)

00154717    Eaton, I; Arthur, J,; Hermanutz, R. et al. (1985) Biological Effects of Continuous
             and Intermittant Dosing of Outdoor Experimental Streams with Chlorpyrifos.
             Unpublished study prepared by US Environmental Protection Agency. 59 p.

00154718    Goodman, L.; Hansen, D.; Middaugh, D.; et al.(1984) Method for early life-stage
             toxicity tests using three atherinid fishes and results with Chlorpyrifos.  Aquatic
             Toxicology: Seventh Symposium Paper 14 d.3054pd4-4-84:145-154.

00154721    Jarvinen, A.; Nordling, B.; Henry, M. (1982) Chronic toxicity of Dursban
             (Chlorpyrifos) to the fathead minnow (Pimephales promelas) and the resultant
             acetylcholinesterase inhibition.  Ecotoxicology and Environmental Safety
             7:423-434.

00154727    Siefert, R. (1984) Effects of Dursban (Chlorpyrifos) on Non-target Aquatic
             Organisms in a Natural Pond Undergoing Mosquito Control Treatment.
             Unpublished report prepared by Environmental  Research Lab.-Duluth. 207 p.

00154732    Jarvinen, A.; Tanner, D. (1982) Toxicity of selected controlled release and
             corresponding unformulated technical grade pesticides to the fathead minnow
             Pimephales promelas. Environmental Pollution 27:179-195.

00155781    Holcombe, G.; Phipps, G.; Tanner, D. (1982) The acute toxicity of kelthane,
             dursban, disulfoton, pydrin, and permethrin to fathead minnows Pimephales
             promelas and rainbow trout Salmo gairdneri. Environ. Pollution 29:167-178.

00158261    Wall, W.; Marganian, V. (1973) Control of salt  marsh Culicoides and Tabanus
             larvae in  small plots with granular organophosphorus pesticides, and the direct
             effect on  other fauna. Mosquito News 33(l):88-93.

05000774    Roberts, D.R.; Miller, T.A. (1970) Effects of Polymer Formulations of Dursban and
             Abate on Non-target Organism Populations, April-October, 1970. Edgewood
             Arsenal, Md.: U.S. Army Environmental Hygiene Agency. (Entomological special
             study no. 31-004-71; avail, from: NTIS, Springfield, Va.: AD-729 342)

05000821    Wallace,  R.R.; West, A.S.; Downe, A.E.R.; Hynes, H.B.N. (1973) The effects of
             experimental blackfly (Diptera, Simuliidae) larviciding with Abate, Dursban, and
             Methoxychlor on stream invertebrates. The Canadian Entomologist
             105(6):817-831.
                                          177

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05000841     All, A.; Mulla, M.S. (1978) Effects of chironomid larvicides and diflubenzuron on
             nontarget invertebrates in residential lakes. Environmental Entomology 7(l):21-27.

05000928     Wall, W. I, Jr.; Marganian, V.M. (1971) Control of Culicoides melleus (Diptera:
             Ceratopogonidae) with granular organophosphorus pesticides, and the direct effect
             on other fauna. Mosquito News 31(2):209-214.

40840902     Burgess, D. (1988) Acute Flow-through Toxicity of Chlorpyrifos to Daphnia
             magna: Final Report No. 37190. Unpublished study prepared by Analytical
             Bio-Chemistry Laboratories, Inc. 158 p.

40840903     Bowman, J. (1988) Acute Flow-Through Toxicity of Chlorpyrifos  to Rainbow
             Trout (Salmo gairdneri): Project ID:  37188. Unpublished study prepared by
             Analytical Bio-Chemistry Laboratories, Inc. 174 p.

40840904     Bowman, J. (1988) Acute Flow-Through Toxicity of Chlorpyrifos  Technical to
             Bluegill Sunfish (Lepomis macrochirus): Project ID:37189. Unpublished study
             prepared by Analytical Bio-Chemistry Laboratories, Inc.  188 p.

40854701     Roberts, N.; Phillips, C. (1987) The Acute Oral Toxicity (LD50) of Chlorpyrifos to
             the Mallard Duck: Project ID: MBS 24/871401. Unpublished study prepared by
             Huntingdon Research Centre Ltd. 25 p.

40854702     Roberts, N.; Phillips, C. (1987) The Dietary Toxicity (LC50) of Chlorpyrifos to the
             Mallard Duck: Project ID: MBS 26/871179. Unpublished study prepared by
             Huntingdon Research Centre Ltd. 20 p.

40854703     Roberts, N.; Phillips, C. (1987) The Dietary Toxicity (LC50) of Chlorpyrifos to the
             Bobwhite Quail: Project ID: MBS 25/871220. Unpublished study prepared by
             Huntingdon Research Centre Ltd. 20 p.

41043901     Smith, G. (1987) Pesticide Use and Toxicology in Relation to Wildlife:
             Organophosphorus and Carbamate Compounds. USDI, Fish and Wildlife Services.
             Resource Publication  170.  2p.

41043903     Jarvinen, A.; Tanner, D.; Kline, E. (1988) Toxicity of Chlorpyrifos Endrin or
             Fenvalerate to Fathead Minnows Following Episodic or Continuous Exposure.
             Ecotoxicology and Environmental  Safety 15: 78-95

41063402     Brown, J.; Chow, L.; Ching, B. (1976) The effect of Dursban upon fresh water
             phytoplankton. Bull, of Environmental Contamination and Toxicology.
             15(4):437-441.
                                          178

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41073401     McCann, J. (1979) Dursban Daphnia magna 21 Day Life Cycle: Biological Report
             of Analysis: Static Test #2405. Unpublished study prepared by U.S. Environmental
             Protection Agency. 1 p.

41205403     ERL-Duluth Pesticide Research Branch (1988) The Effects of Chlorpyrifos on a
             Natural Aquatic System: A Research Design for Littoral Enclosure Studies and
             Final Research Report. Unpublished study prepared by U.S. Environmental
             Protection Agency in cooperation with Univ. of Wisconsin Superior. 200 p.

41205409     Schimmel, S.; Garnas, R.; Patrick, J.; et al. (1983) Acute Toxicity,
             bioconcentration, and persistence of AC 222,705, benthiocarb, Chlorpyrifos,
             fenvalerate, methyl parathion, and permethrin in the estuarine environment. J. of
             Agricultural & Food Chemistry 31(1): 104-113.

41228801     Geyer, H., Sheehan, P. Kotzias, D. et. al. (1982) Prediction of ecotoxicological
             behaviour of chemiacals: Relationship between physico-chemical properties and
             bioaccumulation of organic chemicals in mussel mytilus edulis. Chemosphere.
             11(11): 1121-1134.

41654701     Atkins, E.; Kellum, D. (1990) A Compilation of Data Concerning the Effects of
             LORSBAN Applications on Honey Bees.  Unpublished study prepared by
             University of California, Riverside. 19 p.

41885201     Campbell, S.; Hoxter, K.; Jaber, M. (1970) XRM 5160 (Microencapsulated
             Insecticide): An Acute Oral Toxicity Study with the Northern Bobwhite: Lab
             Project Number: 103-352. Unpublished study prepared by Wildlife International
             Ltd.  20 p.

41885202     Mayes, M.; Servinski, M.; Gorzinski, S. et al. (1991) XRM 5160
             (Microencapsulated Insecticide): The Response of Daphnia magna in a 48 Hour
             Static Acute Test: Lab Project No: ES-DR-0320-1647-4. Unpublished study
             prepared by The Dow Chemical Co. 28 p.

41885203     Mayes, M.; Gorzinski, S.; Richardson,  C.; et al. (1991) XRM 5160
             (Microencapsulated Insecticide): Acute Toxicity to the Bluegill, Lepomis
             macrochirus Rafmesque: Lab Project Number: ES-DR-0320-1647-6. Unpublished
             study prepared by The Dow Chemical Co. 27 p.

41885204     Mayes, M.; Gorzinski, S.; Richardson,  C.; et al. (1991) XRM 5160
             (Microencapsulated Insecticide): Acute Toxicity to the Rainbow Trout,
             Oncorhynchus mykiss Walbaum: Lab Project Number: ES-DR-0320-1647-5.
             Unpublished study prepared by The Dow Chemical Co. 27 p.
                                          179

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41965501     Long, R.; Smith, G.; Beavers, J. (1991) XRM 5160 (Microencapsulated
             Insecticide): A Dietary LC50 Study with the Mallard: Lab Project Number:
             103-351 A.  Unpublished study prepared by Wildlife  International Ltd.  33 p.

41965502     Long, R.; Smith, G.; Beavers, J. (1991) XRM 5160 (Microencapsulated
             Insecticide): A Dietary LC50 Study with the Northern Bobwhite: Lab Project No:
             103/350A. Unpublished study prepared by Wildlife International Ltd. 33 p.

42144901     Hakin, B. (1990) The Effect of Dietary Inclusion of Chlorpyrifos on Reproduction
             in the Mallard Duck: Lab Project Number: MBS 28/88 1667.  Unpublished study
             prepared by Huntingdon Research Centre Ltd.  180 p.

42144902     Hakin, B. (1990) The Effect of Dietary Inclusion of Chlorpyrifos on Reproduction
             in the Bobwhite Quail 6Vol 1,11: Lab Project Number MBS 27/881666.
             Unpublished study by Huntingdon Research Centre Ltd.  318 p.

42144903     Booth, G. (1989) A Simulated Field Study (Using Large Pens) on the Effect of
             Pyrinex 4E (Chlorpyrifos) on Bobwhite Quail: Lab Project Number: ELI/MAA-88.
             Unpublished study prepared by Environmental Labs, Inc. 167 p.

42144904     Surprenant, D.  (1989) Acute Toxicity of Chlorpyrifos to Sheepshead Minnow
             (Cyprinodon variegatus) Under Flow-through Conditions: Lab Project Number:
             89-1-2909.  Unpublished study prepared by Springborn Life Sciences, Inc. 36 p.

42144905     Suprenant, D. (1989) Acute Toxicity of Chlorpyrifos to Eastern Oyssters
             (Crassostrea virginica) Under Flow-Through Conditions: Lab Project Number:
             89-2-2931.  Unpublished study prepared by Springborn Life Sciences, Inc. 41 p.

42144906     Surprenant, D.  (1989) Acute Toxicity of Chlorpyrifos Technical to Mysid Shrimp
             (Mysidopsis bahia) Under Flow-Through Conditions: Lab Project Number:
             89-2-2931.  Unpublished study prepared by Springborn Life Sciences, Inc. 37 p.

42495405     Hansen, S.; Woodburn, K.; Ball, T.; et al. (1992) Chlorpyrifos: Distribution and
             Metabolism in  the Eastern Oyster, Crassostrea virginica: Lab Project Number:
             DECO-ES-2377. Unpublished study prepared by The Dow Chemical Co.  50 p.

42495406     Thacker, J.; Strauss, K.; Smith, G. (1992) Chlorpyrifos: A Bioconcentration Test
             with the Eastern Oyster (Crassostrea virginica): Lab Project Number: 103 A-105:
             DSI/OYSBIO:  ES-DR-0043-4946-8. Unpublished study prepared by Wildlife
             International Ltd. 67 p.

42664901     Sved, D.; Drottar, K.;  Swigert, J.; et al. (1993) A Flow-through Life-cycle Toxicity
             Test with the Saltwater Mysid (Mysidopsis bahia): Chlorpyrifos: Final  Report: Lab
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             Project Number: 103A-103C: ES-DR-0043-4946: ES-2506. Unpublished study
             prepared by Wildlife International Ltd.  57 p.

42834401     Mayes, M.; Weinberg, J.; Rick, D.; et al. (1993) Chlorpyrifos: A Life-Cycle
             Toxicity Test with the Fathead Minnow, Pimephales promelas Rafinesque: Lab
             Project Number: ES-DR-0043-4946-9: DECO-ES-2557B.  Unpublished study
             prepared by The Environmental Toxicology & Chemistry Research Lab.  108 p.

43065601     McCormick, R.; Melichar, M. (1993) Letter Sent to Office  of Pesticide Programs
             dated Dec. 17, 1993 regarding several suspected water contaminations following
             applications of Dursban TC and Equity.  Prepared by DowEloanco. 43 p.

43216401     Giddings, J. (1993) Chlorpyrifos (Lorsban 4E): Outdoor Aquatic Microcosm Test
             for Environmental Fate and Ecological Effects: Final Report: Lab Project No:
             92/6/4288: Unpublished  study by Springborn Lab., Inc. 670 p.

43216402     Giddings, J. (1993) Chlorpyrifos (Lorsban 4E): Outdoor Aquatic Microcosm Test
             for Environmental Fate and Ecological Effects of Combinations of Spray and Slurry
             Treatments: Final Report: Lab Project Number: 92/11/4486: 12550/0392/6104/310.
             Unpublished study by Springborn Lab., Inc. 323 p.

43216403     Racke, K.; Woodburn, K. (1994) Chlorpyrifos Aquatic Nontarget Organism Impact:
             Pond Microcosm Results and Risk Assessment Strategy: Lab Project No: GH/C/-
             3268. Unpublished study by North American Chemistry Lab., DowElanco. 59 p.

43319201     Havens, P.; Cryer, S.; Rolston, L. (1994) Chlorpyriphos Runoff: Regional
             Assessment of Potential Aquatic Impact in the Midwest Corn Belt: Lab Project
             Number: GH/C/3328. Unpublished study prepared by North American
             Environmental Chemistry Lab.  111 p.

43483101     Frey, L.; Palmer, D.;  Krueger, H. (1994) Lorsban Insecticide: An Evaluation of Its
             Effects Upon Avian and Mammalian Species On and Around Corn Fields in Iowa:
             Lab Project Number: 103-366: ES-2524. Unpublished study prepared by MVTL
             Labs, Inc. and Wildlife International, Inc. 1273 p.

43483102     Fontaine, D.  (1994) A Statistical Review of the Effects of Chlorpyrifos Insecticidal
             Treatments Upon Avian Abundance, Avian Casualties, and Vertebrate Casualties in
             Iowa Cornfields: Lab Project Number: DECO-ES-2886. Unpublished study
             prepared by The Dow Chemical Co. 101 p.

43706701     Fontaine, D.  (1995) A Statistical Review of the Effects of Chlorpyrifos Insecticidal
             Treatments upon Avian Abundance, Avian Casualties, and  Vertebrate Casualties in
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             California Citrus Groves: Lab Project Number: DECO-ES-2991. Unpublished
             study prepared by The Dow Chemical Co. 83 p.

43730301     Gallagher, S.; Palmer, D.; Krueger, H. (1994) Lorsban Insecticide: A Pilot Year
             Evaluation of its Effects Upon Avian and Mammalian Species On and Around
             Citrus Groves in California: Lab Project Number: 103-365: ES-2525: RES 92062.
             Unpublished study prepared by MVTL Labs, Inc. and Wildlife Int'l Ltd.  884 p.

43760601     Poletika, N.; Robb, C. (1994) A Field Runoff Study of Chlorpyrifos in Mississippi
             Delta Cotton: Lab Project Number: ENV93030. Unpublished study prepared by
             A&L Great Lakes Labs, Inc.; DowElanco North American Environmental
             Chemistry Lab; and PTRL East, Inc. 499 p.

43760602     Poletika, N.  (1995) Simulation Modeling of A Field Runoff Study of Chlorpyrifos
             in Mississippi Delta Cotton: (Amended Report): Lab Project Number:
             ENV93030.01R. Unpublished study prepared by DowElanco North American
             Environmental Chemistry Lab. 123 p.

43760603     Cryer, S.; Dixon-White, H. (1995) A Field Runoff Study of Chlorpyrifos in
             Southeast Iowa During the  Severe Flooding of 1993: Lab Project Number:
             ENV93008.  Unpublished study by A&L Great Lakes Labs, Inc.; DowElanco North
             American Environmental Chemistry Lab.; and PTRL East, Inc. 822 p.

43760604     Cryer, S. (1994) Predicted Surface Runoff Comparison of Lorsban 4E and Lorsban
             15G Insecticides in the Midwest Corn Growing Region: Lab Project Number:
             GH-C 3275. Unpublished study prepared by DowElanco North American
             Environmental Chemistry Lab. 123 p.

43760605     Cryer, S.; Tollner, E.  (1995) Tillage, Soil Water, and Slope Effects on Banded
             Insecticide Granule Placement: Lab Project Number: ENV92106. Unpublished
             study prepared by University of Georgia. 23 p.

43760608     Ray, S. (1995) An Assessment of the Potential Aquatic Impact Due to Off-Target
             Drift from Aerial Applications of Chlorpyrifos: Lab Project Number: GH-C  3678.
             Unpublished study by DowElanco Modeling and Information Sciences Lab.  63 p.

43760609     Havens, P.; Peacock,  A. (1995) Chlorpyrifos Runoff and Drift: Regional
             Assessment  of Potential Aquatic Impact in Southeastern Peanuts, Mississippi Delta
             Cotton, Red River Sugarbeets, and Mid-Atlantic Tobacco: Lab Project Number:
             GH-C 3633. Unpublished study prepared by DowElanco North American
             Environmental Chemistry Lab. 101 p.
                                         182

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                            Chlorpyrifos Bibliography

43760610     Mihaliak, C. (1995) Validation Report for the Determination of Residues of
             Chlorpyrifos in Water by Immunoassay: Lab Project No: RES93141. Unpublished
             study by DowElanco North American Environmental Chemistry Lab.  57 p.

43760611     Poletika, N.; Dixon-White, H. (1995) Chlorpyrifos Removal from Surface Runoff
             by Vegetated Filter Strips: Lab Project Number: ENV94029. Unpublished study
             by A&L Great Lakes Labs, Inc.; DowElanco; and PTRL East,  Inc. 526 p.

43785201     Worley, K.; Frey, L.; Palmer, D.; et al. (1994) Dursban Insecticide: An Evaluation
             of its Effects Upon Avian and Mammalian Species On and Around Golf Courses in
             Fall in Florida:  (Final Report): Lab Project No: 103-364: ES-2596: RES 92059.
             Unpublished study by MVTL labs, Inc and Wildlife International Ltd. 549 p.

43785202     Fontaine, D. (1995) A Statistical Review of the Effects of Chlorpyrifos Insecticidal
             Treatments Upon Avian Abundance, Avian Casualties, and Vertebrate Casualties in
             Turf in Florida: Lab Project Number: DECO-ES-2992.  Unpublished study
             prepared by The Dow Chemical Co. 99 p.

43786901     Racke, K.; Robb, C.; Ostrander, J. (1994) Field Evaluation of Chlorpyrifos Runoff
             Potential from Turfgrass: Lab Project Number: ENV93085. Unpublished study by
             DowElanco, PTRL-East, Inc., and A&L Great Lakes Labs, Inc. 295 p.

43823901     Poletika, N. (1995) Review of Existing Chlorpyrifos Surface Water Monitoring
             Studies: Lab Project Number: GH-C 3816: 0-149-250-0. Unpublished study
             prepared by DowElanco North American Chemistry Lab. 365 p.

43853201     Cryer, S.; Robb, C. (1995) Chlorpyrifos Runoff Transport and Pond Fate in a
             Southern Iowa Corn Watershed: Lab Project Number: ENV92026: 667:  1577.
             Unpublished study prepared by DowElanco; PTRL East, Inc.; and Minnesota
             Valley  Testing Lab. 957 p.

43853202     Havens, P. (1995) Chlorpyrifos Runoff and Drift: Assessment of Potential Aquatic
             Impact in the Wheat and Alfalfa Use Regions: Lab Project Number: GH-C 3811.
             Unpublished study prepared by DowElanco.  85 p.

43918301     Cryer, S. (1996) Utilizing Simulated Weather Patterns to Predict Runoff
             Exceedence Probabilities for Nonpolar Pesticides: Lab Project Number:  GH-C
             3748.  Unpublished study prepared by DowElanco North American Environmental
             Chemistry Lab. 72 p.

44033401     Cryer, S. (1996) An Overview of the DowElanco Method for Assessing Potential
             Environmental Impact Resulting from Agricultural Usage of Pesticides: Lab Project
                                         183

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                            Chlorpyrifos Bibliography

             Number: GH-C3283.  Unpublished study prepared by Global Environmental
             Chemistry, DowElanco and CIBER, Inc. 27 p.

44033402     Cryer, S.; Nordstrom, P. (1996) Plackett and Bruman Experimental Design
             Sensitivity Analysis for the Environmental Fate Models GLEAMS, SWRRBWQ,
             EPICWQ, and PRZM-2: Lab Project Number: GH-C 3815. Unpublished study by
             North American Environmental Chemistry Laboratory, DowElanco.  53 p.

44055101     Pedersen, C. (1996) Acute Avian Oral Toxicity  (LD50) Study with EF-1315 in
             Bobwhite Quail: Lab Project Number: 153-008-03: DECO-ES-3080. Unpublished
             study prepared by Bio-Life Associates, Ltd.  57 p.

44057101     Gallagher,  S.; Grimes, J.; Beavers, J.; et al. (1996) Lorsban 15G: An  Acute Oral
             Toxicity Study with the House Sparrow: Lab Project Number: 103-417:
             103/040396/HSLD.NC/SUB103: DECO-ES-3132. Unpublished study prepared by
             Wildlife International, Ltd. 41 p.

44057102     Gallagher,  S.; Beavers, J.; Jaber, M. (1996) Chlorpyrifos Technical: An Acute Oral
             Toxicity Study with the House Sparrow: Lab Project Number: 103-418A:
             103/040396/HSLD.NCa/SUB103: DECO-ES-3133. Unpublished  study prepared
             by Wildlife International Ltd. 45 p.

44062601     Pedersen, C. (1996) Acute Avian Dietary Toxicity (LC50) Study with EF-1315 in
             Bobwhite Quail: Lab Project Number: 153-009-01: DECO-ES-3081: ES-3081.
             Unpublished study prepared by Bio-Life Associates, Ltd. 79 p.

44223601     Poletika, N.; Dolder, S. (1997) Chlorpyrifos Removal from Artificial Runoff by
             Vegetative Filter Strips: Lab Project Number: ENV95004: 934: 1859. Unpublished
             study by A&L Great Lakes Labs, Inc.; PTRL East, Inc.; and DowElanco.  356 p.

44235001     Thomas, J.; Chambers, D. (1997) An Analysis of Factors Involved in Suspected
             Well Contaminations by Chlorpyrifos-based Termiticide Emulsions (Dursban TC,
             Equity Termiticide) Based on Water Incident Survey and Analytical Data: Lab
             Project No.: DERBI 48202: 48202. Unpublished study by DowElanco. 16 p.

44585401     Maguire, C.; Williams, B. (1998) Response of thermal stressed bobwhite to
             organophosphorus exposure. Environmental Pollution 47:25-37.

44585403     Thompson-Cowley, L. (1981) Dursban LC50 Tests Bobwhite Quail-Mallard
             Ducks.  Unpublished study prepared by Oregon State University.  24 p.

44585405     Linn, J. (1968) Effects of Low Volume Aerial Spraying of DURSBAN and
             Fenthion on Fish. Down to Earth 24(2):  28-30.
                                         184

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44585408    Thirugnanam, M.; Forgash, A. (1977) Environmental Impact of Mosquito
             Pesticides: Toxicity and Anticholinesterase Activity of Chlorpyrifos to Fish in a
             Salt Marsh Habitat. Archives of Environmental Contamination and Toxicology 5:
             415-425.

44692001    Clements, R.; Bale, J. (1987) The short-term effects on birds and mammals of the
             use of chlopyrifos to control leather] ackets in grassland.  Annual Applied
             Biology(112):41-47.

44692101    Shannon, L.; Yount, J.; Flum, T. (1989) The Effects of Dursban on Aquatic
             Systems: A Comparison Between Mixed Flask Microcosms and Field Enclosures.
             Unpublished study prepared by US EPA.  31 p.

44692201    Mayer, F.; Marking, L.; Bills, T. et al. (1994) Physicochemical factors affecting
             toxicity in freshwater: hardness, pH, and temperature: (chlorpyrifos).  P. 5-22 in
             Bioavailability Physical, Chemical, and Biological Interactions by J. Hamelink, P.
             Landrum, H. Bergman, and W. Benson. Boca Raton, FL: Lewis Publishers.

44709401    Anderson, T.; Richards, S.; McMurray, S. et al. (1998) Avian Response to
             Chlorpyrifos Exposure in Corn Agroecosystems: Lab Project Number: GH-C4698.
             Unpublished study prepared by Ecorisk, Inc. 89 p.

44711601    Poletika, N.; Robb,  C. (1998) A Monitoring Study to Characterize Chlorpyrifos
             Concentration Patterns and Ecological Risk in an Agriculturally Dominated
             Tributary of San Joaquin River: Lab Project Number: ENV96055. Unpublished
             study prepared by Dow AgroSciences and Paragon Research.  561 p.

44823801    Thomas, J.; Chambers, D.  (1999) A Retrospective Analysis of Surface Water
             Contamination-based Termiticide Emulsions (Dursban TC, Equity Termiticide)
             Based on Water Incident Survey and Analytical Data: Lab Project Number: 68513.
             Unpublished study prepared by Dow AgroSciences LLC. 25 p.

45013101    van Wesenbeck, I.; Poletika, N.; Robb, C. (1999) A Monitoring Study to
             Characterize Chlorpyrifos Concentration Patterns and Ecological Risk in an
             Agricultural Dominated Tributary of the San Juaquin River: Part 2:  Lab Project No:
             ENV96055.02. Unpublished study by  Dow AgroSciences LLC.  153 p.

45506303    Henry, K.; Kirk, H. (2001) The Acute Toxicity of Chlorpyrifos to Larval
             Amphibians Using the Bullfrog, Rana catesbeiana, as a Biological Model: Lab
             Project Number: 001249.  Unpublished study by The Dow Chemical Co.  28 p.
Toxicology MRID References
                                          185

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                            Chlorpyrifos Bibliography

00029064     Thompson, D.J.; Gerbig, C.G.; Warner, S.D. (1971) Three Generation
             Reproduction and Teratology Study in the Rat following Prolonged Dietary
             Exposure to Dursban O,O-Diethyl 0-3,5,6-trichloro-2- pyridyl phosphorothioate:
             HH-382. (Unpublished study received Aug 28,  1972 under 3F1306; submitted by
             Dow Chemical U.S.A., Midland, Mich.; CDL:099239-B)

00054352     Warner, S.D.; Gerbig, C.G; Strebing, R.J.; et al. (1980) Results of a Two-Year
             Toxicity and Oncogenic Study of Chlorpyrifos Administered to CD-I Mice in the
             Diet. (Unpublished study received Mar 20, 1980 under 464-343; submitted by Dow
             Chemical U.S.A., Midland, Mich.;  CDL:242059-A)

00064933     McCollister, S.B.; Kociba, R.J.; Gehring, P.J.; et al. (1971) Results of Two-Year
             Dietary Feeding Studies on Dowco1/4(R)|il79 in Beagle Dogs: T35.12-44793-18.
             (Unpublished study received Aug 28, 1972 under 3F1206; submitted by Dow
             Chemical U.S.A., Midland, Mich.;  CDL:092213-A)

00064934     Thompson, D.J.; Gerbig, C.G.; Warner, S.D. (1971) Three Generation
             Reproduction and Teratology Study in the Rat following Prolonged Dietary
             Exposure to Dursban O,O-Diethyl 0-3,5,6-trichloro-2-pyridyl phosphorothioate:
             HH-382. (Unpublished study received Aug 28,  1972 under 3F1306; submitted by
             Dow Chemical U.S.A., Midland, Mich.; CDL:092213-B)

00095268     Deacon, M.M.; Murray, J.S.; Pilny, M.K.; et al.  (1979) The Effects of Orally
             Administered Chlorpyrifos on Embryonal and Fetal Development in Mice.
             (Unpublished study received Aug 16, 1979 under 464-448; submitted by Dow
             Chemical U.S.A., Midland, Mich.;  098912-A)

00130400     Ouellette, I; Dittenber, D.; Kloes, P.; et al. (1983) Chlorpyrifos: Oral Teratology
             Study in Fischer 344 Rats. (Unpublished study  received Aug 15, 1983 under
             3F2947; submitted by Dow Chemical U.S.A., Midland, MI; CDL:071866-A)

00142902     Davies, D.; Tollett, I; Lomax, L. (1985) Chloropyrifos: A Four week Dietary Study
             In CD-I Mice.  Unpublished study  Dow Chemical U.S.A.  154 p.

00146507     Hardy, C.; Jackson, G. (1984) Dursban Technical: Acute Inhalation Toxicity in
             Rats: Report No. DWC 411/84774. Unpublished study prepared by Huntingdon
             Research Centre, pic.  23 p.

00146519     Kociba, R.; McCollister, S.; Keyes, D.; et al. (1985) Results of Two-year Dietary
             Feeding Studies on Dowco 179 in Beagle Dogs: Supplement to Original Report.
             Unpublished report prepared by Dow Chemical  U.S.A.  246 p.
                                         186

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                            Chlorpyrifos Bibliography

00152683     Mendrala, A. (1985) Evaluation of Chlorpyrifos in the Chinese Hamster Ovary
             Cell-Hypoxanthine (Guanine) Phosphoribosyl Transferase (CHO/HGPRT) Forward
             Mutation Assay: Report No. HET K-044793-072.  Unpublished report prepared by
             Dow Chemical USA. 17 p.

00152684     Bhaskar, B.; Gollapudi, V.; Linscombe, A.; et al. (1985) Evaluation of Chlorpyrifos
             in the Mouse Bone Marrow Micronucleus Test: Final Report: TXT:K-044793-067.
             Unpublished report prepared by Dow Chemical Co. 29 p.

00157057     Mendrala, A.; Dryzga, M. (1986) Evaluation of Chlorpyrifos in the Rat Hepatocyte
             Unscheduled DNA Synthesis (UDS) Assay: Final Report: Laboratory Rep Code
             HETK-044793-073. Unpublished study by Dow Chemical U.S.A. 31 p.

00157058     Bruce, R.; Zempel, J. (1986) Chlorpyrifos: Evaluation in the Ames'
             Salmonella/Mammalian-microsome Mutagenicity Assay: Final Report: Lab. Report
             Code TXT:K-044793-075. Unpublished  study by Dow Chemical U.S.A. 16 p.

40013901     Corley, R.; Landry, T.; Calhoun, L.;  et al. (1986) Chlorpyrifos: 13-Week Nose-only
             Vapor Inhalation Exposure Study in Fischer 344 Rats: Laboratory Project Id: HET
             K-044793-077. Unpublished study prepared by Dow Chemical USA. 168 p.

40055001     Landry, T.; Dittenber, D.; Lomax, L.; et al. (1986) Chlorpyrifos:  An Acute Vapor
             Inhalation Toxicity Study with Fischer Rats: Laboratory Project ID:
             HET-K-44793-74: Study ID: K-44793-74. Unpublished  study  prepared by Dow
             Chem Co., Mammalian and Environmental Toxicology Research Lab. 64 p.

40057201     Bruce, R.; Zempel, J. (1986) Chlorpyrifos: Evaluation in the Ames's
             Salmonella/Mammalian-microsome Mutagenicity Assay: Laboratory Project ID:
             HET K-044793-075: Supplemental Data to Mrid 157058. Unpublished study
             prepared by Dow Chemcial Co. lip.

40166501     Corley, R.; Landry, T.; Calhoun, L.;  et al. (1986) Chlorpyrifos: 13-Week Nose only
             Vapor Inhalation Exposure Study in Fischer 344 Rats: Supplemental Data: Lab.
             Proj. ID. HET K-044793-077. Unpublished data by Dow Chemical Co.  14 p.

40436406     Crown, S.; Gur, E.; Nyska, A.; et al.  (1985) Toxicity in Dietary Administration to
             Rats for 13 Weeks oPyrinex : Laboratory Project ID MAK/058/PYRA.
             Unpublished study performed by Life Science Research  Israel  Ltd. 174 p.

40436407     Rubin, Y.; Gal, N.; Waner, T.; et al. (1987)  Teratogenicity Study in The Rat:
             Laboratory Project ID MAK/101/PYR. Unpublished study performed by Life
             Science Research Israel Ltd. 268 p.
                                         187

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                            Chlorpyrifos Bibliography

40436408     Rubin, Y.; Nyska, A.; Waner, T. (1987) Pyrinex Teratogenicity Study in the Rabbit:
             Laboratory Project ID MAR/103/PYR.  Unpublished study performed by Life
             Science Research Israel Ltd. 208 p.

40436409     Loveday, K. (1987) In vitro Chromosomal Aberration Assay on Pyrinex
             (Chlorpyrifos). Unpublished study performed by Arthur D. Little, Inc. 40 p.

40436411     Loveday, K.; Findlen, K.; Yadlon, S. (1987) Evaluation of Pyrinex in the Ames
             Mutagenesis Assay: ADL Reference 59487-00.  Unpublished study performed by
             Arthur D. Little, Inc. 30 p.

40458901     Nolan, R.; Dryzga, M.; Landenberger, B.; et al.  (1987) Chlorpyrifos: Tissue
             Distribution and Metabolism of Orally Administered Carbon 14-Labeled
             Chlorpyrifos in Fischer 344 Rats: Laboratory Project Study ID: K-044793-(76).
             Unpublished study prepared by Dow Chemical Co. 61 p.

40908401     Newton, P. (1988) A Thirteen Week Nose-Only Inhalation Toxicity Study of
             Chlorpyrifos Technical (Pyrinex) in the Rat: Project No. 88-8058. Unpublished
             study prepared by Bio/dynamics, Inc. 587 p.

40952801     Szabo, I; Young, J.; Grandjean, M. (1988) Chlorpyrifos: 13-Week Dietary Toxicity
             Study in Fischer-344 Rats: Project ID: File No.  TXT:K-044793-071. Unpublished
             study prepared by Dow Chemical Co. 242 p.

40952802     Young, J.; Grandjean, M. (1988) Chlorpyrifos: 2-Year Dietary Chronic
             Toxicity-Oncogenicity Study in Fischer-344 Rats: Study ID: TXT:K/044793/079.
             Unpublished study prepared by Dow Chemical Co. 990 p.

40972801     Calhoun, L.; Johnson, K. (1988) Chlorpyrifos: 4-Day Dermal Probe and 21-day
             Dermal Toxicity Studies in Fischer 344 Rats: Proj. ID(S) K-044793-085;
             K-044793-086. Unpublished study prepared by Dow Chemical Co.  191 p.

41340201     Calhoun, L.; Johnson, K. (1989) Supplemental Information to the Report Entitled:
             Chloropyrifos: 4-Day Dermal Probe and 21-Day Dermal Toxicity Studies in Fischer
             344 Rats (MRID 40972801, Dated  September 1, 1988): Lab Project Number:
             K/044793/085; K/044793/086.  Unpublished study by Dow Chemical Co. 8 p.

41340203     McClintock, M.; Gollapudi, B. (1989) Evaluation  of Chloropyrifos in the Bone
             Marrow Micronucleus Test: Lab Project Number: TXT/K/044793/067A.
             Unpublished study prepared by Dow Chemical Co. 24 p.

41930301     Breslin, W.; Liberacki, A.; Dittenber, D. et al. (1991) Chlorpyrifos:
             Two-Generation Dietary Reproduction Study in Sprague-Dawley Rats: Lab Project
                                         188

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                            Chlorpyrifos Bibliography

             Number: K-044793-088: Fl: F1W:F2W. Unpublished study prepared by Dow
             Chemical Co., Tox. Research Lab.  1181 p.

42008401     Vaccaro, I; Nolan, R.; Hugo, 1; et al. (1991) Evaluation of Dislodgable Residues
             and Absorbed Doses of Chlorpyrifos to Crawling Infants Following Indoor
             Broadcast Applications of a Chlorpyrifos Based Emulsifiable Concentrate: Lab
             Project No: DECO HEH2.1-1-182(95). Unpublished study by Dow Chem. Co. 84 p.

42031701     Vaccaro, ?. et al. (1991) Validation data in Support of Chlorpyrifos Dislodgable
             Residue/Human Absorption Study: Lab Project Number: A1AEC41 THUMAN
             AM.  Unpublished study prepared by The Dow Chemical Co.  61 p.

42172801     Barker, M. (1989) Chlorpyrifos Oral Toxicity Study in Beagle Dogs (Repeated
             Daily Dosage for 13 Weeks): Lab Project Number: MBS 31/88999. Unpublished
             study prepared by Huntingdon Research Centre Ltd.  209 p.

42172802     Crown, S. (1990) Pyrinex Technical Oncogenicity Study in the Rat: Lab Project
             Number: MAK/095/PYR. Unpublished study prepared by Life Science Research
             Israel, Ltd.  1591 p.

42495404     Wilmer, J.; Berdasco, N.; Crissman, J. (1992) Chlorpyrifos: Acute Oral Toxicity
             (Range-finding) Study in Fischer 344 Rats: Lab  Project Number: K-044793- 093 A:
             K-044793-093R. Unpublished study by The Dow Chemical Co.  28 p.

42534201     Gur,  E. (1992) Prinex Technical: Oncogenicity Study in the Mouse: Lab Project
             No: MAK/106/PYR.  Unpublished study by Life Science Research Israel Ltd.  1238
             P-

42669101     Wilmer, J.; Berdasco, N.; Crissman, J.; et al. (1992) Chlorpyrifos: Acute
             Neurotoxicity Study in Fischer 344 Rats: Lab Project Number: K-044793-093B:
             K-044793-093C: K-044793-093D. Unpublished study prepared by The Dow
             Chemical Co., Toxicology Research Lab.  271 p.

42929801     Shankar, M.; Bond, D.; Crissman, J. (1993) Chlorpyrifos: 13-Week Neurotoxicity
             Study in Fischer-344 Rats: Lab Project Number: K-044793-094. Unpublished
             study prepared by The Toxicology Research Lab., Dow Chemical Co. 535 p.

42943101     Spencer, P.; Albee, R.; Mattsson, J. (1993) Positive Control Exercises: Motor
             Activity, Functional Observational Battery and Neuropathology (with
             Chlorpyrifos). Unpublished study prepared by Dow Chemical Co. 137 p.

43426601     Maurissen, J. (1994) Chlorpyrifos: Range Finding (Pilot) Subchronic Neurotoxicity
             Study in Rats: Lab Project Number: K/044793/096. Unpublished study. 3 p.
                                         189

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                            Chlorpyrifos Bibliography

44020901     Maurissen, I; Shankar, M.; Mattsson, J. (1996) Chlorpyrifos: Cognitive Study in
             Adult Long-Evans Rats: Lab Project Number: K-044793-096.  Unpublished study
             by The Toxicology Research Laboratory, The Dow Chemical Co. 691 p.

44035001     Vaccaro, J.; Nolan, R.; Murphy, P. et al. (1993) Estimation of the Absorbed Dose of
             Chlorpyrifos to Adult Volunteers, Following Treatment of Carpeting with Empire
             20 Insecticide: Lab Project Number: DECO-HEH2.1-1-182(123):
             HEH2.12-38-1(32). Unpublished study prepared by Industrial Hygiene Research &
             Technology, The Dow Chemical Co. 76 p.

44209101     Stebbins, K. (1996) Dursban F Insecticidal Chemical: Acute Oral Toxicity Study in
             Fischer 344 Rats: Lab Project Number: K-044793-102A: K-044793-102A1.
             Unpublished study  prepared by The Dow Chemical Co. 54 p.

44209102     Stebbins, K. (1996) Dursban F Insecticidal Chemical: Acute Dermal Toxicity Study
             in New Zealand White Rabbits: Lab Project Number: K-044793-102D:
             K-044793-102D1.  Unpublished study by The Dow Chemical Co.  41 p.

44209103     Stebbins, K. (1996) Dursban F Insecticidal Chemical: Primary Eye Irritation Study
             in New Zealand White Rabbits: Lab Project Number: K-044793-102C.
             Unpublished study  prepared by The Dow Chemical Co. 16 p.

44209104     Stebbins, K. (1996) Dursban F Insecticidal Chemical: Primary Dermal Irritation
             Study in New Zealand White Rabbits: Lab Project Number: K-044793-102B.
             Unpublished study  prepared by The Dow Chemical Co. 16 p.

44209105     Stebbins, K. (1996) Dursban F Insecticidal Chemical: Dermal Sensitization
             Potential in Hartley Albino Guinea Pigs: Lab Project Number: K-044793-102E:
             GPIGS02/27/96: GPIGSO1/10/96. Unpublished study prepared by The Dow
             Chemical Co. 20 p.

44273901     Dittenber, D. (1997) Chlorpyrifos: Evaluation of Single Oral Doses on
             Cholinesterase and Neurotoxic Esterase Inhibition in F344 Rats: Lab Project
             Number: 960036.  Unpublished study by The Dow Chemical Co. 27 p.

44533401     Linscombe, V.; Mensik, D.; Clem, B. (1992) Evaluation of Chlorpyrifos in an in
             vitro Chromosomal Aberration Assay Utilizing Rat Lymphocytes: Lab Project
             Number: K-044793-092. Unpublished study by The Dow Chemical Co. 32 p.

44556901     Hoberman, A. (1998) Developmental Neurotoxicity Study of Chloropyrifos
             Administered Orally via Gavage to Crl:CD BR VAF/Plus Presumed Pregnant Rats:
             Lab Project Number: 304-001: K-044973-109.  Unpublished study prepared by
             Argus Research Laboratories, Inc.  833 p.
                                         190

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44648101     Mattsson, I; Maurissen, I; Spencer, P. et al. (1998) Effects of Chlorpyrifos
             Administered via Gavage to CD Rats During Gestation and Lactation on Plasma,
             Erythrocyte, Heart and Brain Cholinesterase, and Analytical Determination of
             Chlorpyrifos and Metabolites: Lab Project Number: 971162. Unpublished study
             prepared by The Dow Chemical Company. 322 p. Relates to L0000448.

44648102     Mendrala, A.; Brzak, K. (1998) Chlorpyrifos: Part A- Concentration-Time Course
             of Chlorpyrifos and Chlorpyrifos-Oxon in Blood (in Rats): Lab Project Number:
             971187A. Unpublished study by The Dow Chemical Company. 63 p.

44810701     Mendrala, A.; Engle, K. (1999) Chlorpyrifos: Part B-In Vitro Determination of
             A-Esterase Activity in Liver and Blood Towards Chlorpyrifos-Oxon: Lab Project
             Number: 971187. Unpublished study by The Dow Chemical Company.  51 p.

44811002     Kisicki, I; Wilkinson Seip, C.; Combs, M. (1999) A Rising Dose Toxicology Study
             to Determine the No-Observable-Effect-Levels (NOEL) for Erythrocyte
             Acetylcholinesterase (AChE) Inhibition and Cholinergic Signs and Symptoms of
             Chlorpyrifos at Three Dose Levels: Lab Project Number: 21438: DR#
             K-044793-284: 432-01. Unpublished study prepared by MDS Harris. 578 p.

44884301     Cieszlak, F. (1999) Chlorpyrifos Oxon: Acute Oral Toxicity Study in Fischer 344
             Rats: Lab Project Number: 991064. Unpublished study prepared by The Dow
             Chemical Company.  67 p. (OPPTS 870.1100}

44889501     lachan, R.; Nishioka, M.; Van Dyck, K. et al. (1999) TCP Biomonitoring Study:
             Lab Project Number: GH-C 4946. Unpublished study prepared by Battelle Centers
             for Public Health Research and Evaluation. 138 p.

45098001     lachan, R.; Nishioka, M.; van Dyck, K. (2000) TCP Biomonitoring Follow-Up
             Study: Final Report: Lab Project Number: FN003330: GH-C 5064.  Unpublished
             study prepared by Battelle. 28 p.

45195701     lachan, R.; Nishioka, M.; Dyck, K. (2000) TCP Biomonitoring Second Follow-Up
             Study: Final Report: Lab Project Number: MN101181. Unpublished study
             prepared by Battelle and Battelle Memorial Institute. 19 p.

45195702     Salazar, R. (2000) Pesticide Exposure Assessment: Downey Residence:
             (Chlorpyrifos):  Lab Project Number: JJJ080800.  Unpublished study prepared by
             Salazar & Spaul Environmental Consultants, Inc.  33 p.

45195703     Summer, S.  (2000) Analysis of 3,5,6-Trichloro-2-pyridinol Residue in Urine: Final
             Analytical Phase Report: Lab Project Number: AG000008. Unpublished study
             prepared by Battelle. 89 p.
                                         191

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45195704    Cleveland, C. (2000) Follow-Up Report on Downey Residence: TCP Urine
             Analysis and Environmental Samples: Lab Project Number: JJJ081400:
             MN101181.  Unpublished study prepared by Dow AgroSciences LLC. 69 p.

45195705    Summer, S.; Biehl, D.; Nishioka, M. (2000) Chlorpyrifos Exposure
             Assessment-Analysis of 3,5,6-Trichloro-2-pyridinol Residue in Urine: Final
             Analytical Phase Report: Lab Project Number: N003330A: FN003330.
             Unpublished  study prepared by Battelle.  160 p.

45360101    Mattsson, I;  Holden, L.; Eisendrandt, D. et al. (2001) Reanalysis with Optimized
             Power of Red Blood Cell Acetylcholinesterase Activity From a 1-Year Dietary
             Treatment of Dogs to Chlorpyrifos: Lab Project Number: GHC-5127. Unpublished
             study prepared by Dow AgroSciences LLC. 32 p.

45360102    Hoberman, A. (2000) Developmental Neurotoxicity Study of Chlorpyrifos
             Administered Orally via Gavage to Crl:CD BR VAF/Plus Presumed Pregnant Rats:
             Lab Project Number: 304-001: K-044793-109. Unpublished study prepared by
             Argus Research Laboratories, Inc. 28 p.

45467301    Marable, B.; Baker, P.; Stebbins, K. et al. (2001) Chlorpyrifos Technical: 6-Week
             Dietary Study of Acetylcholinesterase Inhibition in Beagle Dogs: Lab Project
             Number: 011036. Unpublished study by The Dow Chemical Company. 194 p.

45467302    Stebbins, K. (2001) Chlorpyrifos Technical: 6-Week Dietary Study with
             Histopathological Evaluation of the Adrenal Glands in Beagle Dogs: Lab Project
             Number: 011039. Unpublished study by The Dow Chemical Company. 18 p.
Occupational and Residential MRID References

40026001     Vaccaro, J. (1986) Evaluation of Airborne and Whole Body Exposure of Lawn Care
             Specialists to Chlorpyrifos During Routine Treatment of Turf: Laboratory Project
             Identification: GH-P 1300. Unpublished study prepared by Dow Chemical  U.S.A.,
             Agricultural Products Dept.  69 p.

40094001     Vaccaro, J.; Bohl, R.; Skowronski, B.; et al. (1987) Airborne Chlorpyrifos
             Concentrations Measured During and Following Applications of Dursban TC
             Insecticide to Residential Dwellings. Unpublished study prepared by Industrial
             Hygiene Laboratory, Dow Chemical Co. 53 p.

41540202     Wetters, J.; McKellar, R.; Ordiway,  T.; et al. (1985) Dislodgeable Residues of
             Chlorpyrifos on Turf Grasses following a Foliar Application of Dursban 4E
                                          192

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                            Chlorpyrifos Bibliography

             Insecticide or Dursban SOW: Lab Project ID.: GH-C 1774.  Unpublished study
             prepared by Dow Chemical U.S.A., Agricultural Products Dept.  27 p.

42887201     Contardi, J. (1993) An Evaluation of the Appropriate Drying Time via Air
             Monitoring, Dislodgable Residue Determination, and Carpet Weight Loss, After
             Applying Dursban LO Insecticide to a Carpeted Surface, Indianapolis, Indiana,
             September 22, 1992: Lab Project Number: DECO-HEH2.1-1-182(126):
             HEH2.1-1-182(126).Unpublished study prepared by Dow Chemical Co., Health and
             Environmental Sciences. 29 p.

42974501     Shurdut, B.; Murphy, P.; Nolan, R.; et al. (1993) Lorsban 4E and SOW Insecticides:
             Assessment of Chlorpyrifos Exposures to Applicators, Mixer/Loaders, and Re-entry
             Personnel During and Following Application to Low Crops: Lab Project Number:
             DECO-HEH2.1-1-182(118): DECO-HEH2.1-1-182(124). Unpublished study
             prepared by Industrial Hygiene Department, DowElanco. 333 p.

42994401     Day, E.; Chen, W.; Nolan, R.; et al. (1993) Chlorpyrifos: An Exposure Assessment
             of Workers Associated with Mixing/Loading, Application and Reentry Following
             Ground Boom Application to Low Crops: Lab No: GH-C3116. Unpublished study
             by DowElanco, North American Environmental Chemistry Lab.  45 p.

43013501     Vaccaro, J.; Nolan, R.; Hugo, J.; et al. (1993) Chlorpyrifos: Exposure to Adults and
             Children upon Reentry to Domestic Lawns, Following Treatment with a
             Chlorpyrifos-Based Mixture: Lab Project Number: DECO/HEH2/1/1/182/121.
             Unpublished study prepared by Industrial Hygiene Research & Technology, The
             Dow Chemical Co. 75 p.

43013502     Hugo, J.; Berryman, K. (1993) Evaluation of Industrial Hygiene Monitoring
             Method DOWM 100863-HE90a for Determining Chlorpyrifos in Air During
             Applications of Chlorpyrifos Formulations: Lab Project No: HEH2/12/38/26/27.
             Unpublished study by The Analytical Chemistry Lab., The Dow Chemical Co. 43 p.

43013503     Hugo, J.; Murphy, P.; Charron, K. (1993) Dursban Turf Insecticide: Evaluation and
             Validation of Monitoring Methods for Assessing Worker Exposures: Lab Project
             Number: DECO-HEH2/12/38/26/7. Unpublished study prepared by The
             Analytical Chemistry Lab., The Dow Chemical Co. 33 p.

43027901     Contardi, J.; Gilbert, J.; Lambesis, D.; et al (1993) Evaluation of Chlorpyrifos
             Exposures During Mixing/Loading and Application of EMPIRE 20 Insecticide to
             Ornamental Plants in  Commercial Greenhouses: Lab Project Number:
             CO-HEH2.1-1-182(130): CO-HEH2.12-38-26(10).  Unpublished study prepared by
             The Dow Chemical Co. 208 p.
                                         193

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                            Chlorpyrifos Bibliography

43042001     Nolan, R.; Vacarro, 1; Schnelle, K.; et al. (1993) Chlorpyrifos: Exposure
             Assessment for Adults and Children Entering and Playing on Lawns Treated with
             Dursban Turf Insecticide: Lab Project Number: GH/C/3179.  Unpublished study
             prepared by DowElanco North American Environmental Chemistry Lab. 20 p.

43062701     Honeycutt, R.; DeGeare, M. (1993) Worker Reentry Exposures to Chlorpyrifos in
             Citrus Treated with Lorsban 4E Insecticide: Lab Project Number: 91-102HE:
             93-307: DECO-HEH2.2-1-182(125)B. Unpublished study prepared by H.E.R.A.C.,
             Inc. and The Dow Chemical Co.  950 p.

43062702     Day, E. (1993) Chlorpyrifos: An Exposure Assessment of Re-entry Workers
             Following Application in Citrus Crops: Lab Project Number: GH-C 3184.
             Unpublished  study prepared by DowElanco  17 p.

43042002     Shurdut, B. (1993) Chlorpyrifos: An Exposure and Risk Assessment for
             Workers/Loading and Applying EMPIRE 20 Insecticide to Ornamentals in
             Greenhouses: Lab Project Number: GH/C3175.  Unpublished study prepared by
             DowElanco North American Environmental Chemistry Lab.  39 p.

43138101     Chen, W.; Day, E.; Nolan, R. et al. (1994) Chlorpyrifos: An Exposure and Risk
             Assessment of Workers Associated with Air Blast Sprayer Application of
             LORSBAN 4E to High Crops (Citrus): Lab Project No: GH-C3224. Unpublished
             study by North American Environmental Chemistry Lab., DowElanco. 50 p.

4313 8102     Honeycutt, R.; DeGeare, M. (1994) Evaluation of the Potential Exposure of
             Workers to Chlorpyrifos During Mixing and Loading, Spray Application, Clean-Up
             Procedures During the Treatment of Citrus Groves with Lorsban* 4E Insecticide:
             Lab Project Number: 91-101HE: 93-308: O-HEH2.1-1-182(125)A. Unpublished
             study prepared by H.E.R.A.C., Inc. 1061 p.

43798001     Nolan, R. (1995) Letter sent to John Fitt (DowElanco) dated September 18, 1995:
             Itemized list of additional information requested by USEPA, Health Effects Div.:
             (Developmental toxicity and birth defects:  Chlorpyrifos). Prepared by The Dow
             Chemical Co. 277 p.

43963701     Maxey, S.; Murphy, P.; Berbrich, D. (1995) Determination of Dislodgeable
             Residues and Airborne Chlorpyrifos Concentrations Following Broadcast
             Treatment of a Carpeted Surface with NAF-53 (0.5%) Emulsifiable Concentrate:
             Lab Project Number: HEH 23: DECO-HEH-23:  HEH 19. Unpublished study
             prepared by The Dow Chemical Co.  118 p.
                                         194

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                            Chlorpyrifos Bibliography

44039901     Burns, C.; Cartmill, J.; Powers, B.; et al. (1996) An Update of the Moribidity (sic)
             Experience Among Employees Potentially Exposed to Chlorpyrifos: Lab Project
             Number: EPI-3635. Unpublished study by The Dow Chemical Co.  85 p.

44167101     Vaccaro, J.; Beard, K.; Maxey, S.; et al. (1996) Chlorpyrifos: Exposure to Adults
             and Children Upon Re-Entry to Domestic Lawns, Following Treatment with a
             Chlorpyrifos-Based Granular Insecticide: Lab Project Number:
             HEBE. 1-1-182(134). Unpublished study by The Dow Chemical Co. 75 p.

44186301     Gibson, J. (1996) Critical Review of Allegations Associating Dursban with Human
             Teratogenicity: Lab Project Number: JEG122396. Unpublished study prepared by
             DowElanco.  2401  p.

44245801     Shurdut, B.; Chen,  W.; Burns,  C.; et al. (1997) Critical Assessment of Report
             Entitled "Review of Chlorpyrifos Poisoning Data" (by J. Blondell and V. Dobozy,
             January 14,  1997):  Lab Project Number: GH-C 4359. Unpublished study prepared
             by DowElanco.  118 p.

44444801     Vaccaro, J.; Murphy, P.; Marino, T. et al. (1997) Determination of Exposure and
             Dose of General Pest Control Operators to Chlorpyrifos During Routine
             Applications of Dursban Pro Insecticide to Cracks/Crevices and Spots: Lab  Project
             Number: HEH 785. Unpublished study by Dow Chemical Co.  46 p.

44458201     Byrne, S.; Saunders, D.;  Cook, W. et al. (1998) Residential Exposure to
             Chlorpyrifos from Reentry to Structures Treated with Crack and Crevice and Spot
             Applications of Dursban Pro: Lab Project Number: HEA97044.  Unpublished study
             prepared by Dow AgroSciences.  133 p. (OPPTS 875.2400, 875.2500, 875.2600,
             875.2800, 875.2900, 875.2000}

44589001     Murphy, P.; Beard, K.; Chambers, D. et al. (1997) Evaluation of Worker's
             Exposures to Chlorpyrifos During the use of Dursban TC Termiticide Concentrate
             for Pre-Construction Termiticide Applications: Lab Project Number: HEH 816.
             Unpublished study prepared by Dow Chemical Company. 96 p.

44483501     Murphy, P.; Beard, K.; Marino, T. et al. (1998) Evaluation of Chlorpyrifos
             Exposures to Workers During Loading and Application of Lorsban 15G Granular
             Insecticide During  Corn  Planting: Lab Project Number: HEH 311. Unpublished
             study prepared by Dow Chemical Co. 95 p.

44729401     Barnekow, D.; Shurdut, B.  (1998) Evaluation of Workers' Exposure to Chlorpyrifos
             during the Use of Dursban Pro Insecticide Concentrate for Broadcast Turf
             Applications: Lab Project Number: HEA97089. Unpublished study prepared by
                                         195

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                            Chlorpyrifos Bibliography

             Dow Agrosciences LLC. 185 p. (OPPTS 875.1000, 875.1100, 875.1300,
             875.1500, 875.2800, 875.1600}

44729402     Barnekow, D.; Shurdut, B. (1998) Evaluation of Workers' Exposures to
             Chlorpyrifos during the Use of Dursban TC Termiticide Concentrate for
             Post-Construction Termiticide Applications: Amended Report: Lab Project
             Number: HEA97054. Unpublished study prepared by Dow Agrosciences LLC.  177
             p. {OPPTS 875.1000, 875.1100, 875.1200, 875.1300, 875.1400, 875.1500,
             875.2800,875.1600}

44739301     Barnekow, D.; Cook, W.; Meitl, T. et al. (1999) Exposure to Chlorpyrifos while
             Applying a Ready to Use Formulation: Lab Project Number: HEA97046.
             Unpublished study prepared by Dow AgroSciences LLC. 134 p. {OPPTS
             875.2000, 875.2400, 875.2500, 875.2600, 875.2800, 875.2900}

44739302     Knutson, I; Barnekow, D.; Cook, W. et al. (1999) Evaluation of Potential
             Exposures to Workers Mixing and Loading Lorsban-4E Insecticide Products for
             Aerial Application: Lab Project Number: HEA97038. Unpublished study prepared
             by DowAgroSciences LLC. 216 p. {OPPTS 875.1000, 875.1100, 875.1300,
             875.1500,875.1600}

44748101     Bargar, E.; Robb, C. (1999) Dissipation of Dislodgeable Foliar Residues of
             Chlorpyrifos from Treated Orchard Trees: Lab Project Number: RES98002: C0177.
             Unpublished study prepared by Dow AgroSciences LLC. 210 p.

44748102     Bargar, E.; Robb, C. (1999) Dissipation of Dislodgeable Foliar Residues of
             Chlorpyrifos from Treated Cotton, Sugar Beet and Sweet Corn Row Crops: Lab
             Project No: RES98027. Unpublished study by Dow AgroSciences LLC.  189 p.
Environmental Fate MRID References

00025619    Bidlack, H.D. (1979) Degradation of Chlorpyrifos in Soil under Aerobic,
            Aerobic/Anaerobic and Anaerobic Conditions. Method GH-C 1258 dated Nov 29,
             1979.  (Unpublished study received Dec 19, 1979 under 464-448; submitted by Dow
            Chemical U.S.A., Midland, Mich.; CDL:241547-A)

00155577    McCall, P.  (1986) Hydrolysis of Chlorpyrifos in Dilute Aqueous Solution:  GH-C
             1791.  Unpublished study prepared by Dow Chemical U.S.A.  29 p.

00155636    McCall, P.  (1985) Column Leaching and Sorption Studies with Chlorpyrifos :GH-C
             1777.  Unpublished study prepared by Dow Chemical U.S.A.  12 p.
                                         196

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                             Chlorpyrifos Bibliography

00155637    McCall, P. (1985) Chlorpyrifos Aged Soil Column Leaching Study: GH- C 1778.
             Unpublished study prepared by Dow Chemical U.S.A. 20 p.

40026101    McCall, P. (1986) Photodegradation of Chlorpyrifos in Aqueous Buffer: Laboratory
             Project Identification: GH-C 1862: (6015-293). Unpublished study prepared by
             Hazleton Laboratories America, Inc.  59 p.

40050401    McCall, P. (1986) Column Leaching and Sorption Studies with Chlorpyrifos and
             Chlorpyrifos Aged Soil Column Leaching Study: Supplemental Data.  Unpublished
             compilation prepared by Dow Chemical  U.S.A.  13 p.

40056401    Murphy, P.; Lutenske, N. (1986) Bioconcentration of Chlorpyrifos in Rainbow
             Trout (Salmo gairdneri Richardson):  Laboratory Project Identification: ES-928.
             Unpublished study prepared by Dow Chemical Co. 49 p.

40059001    Oliver, G.; McKellar, R.; Woodburn, K.; et al. (1987) Field Dissipation and
             Leaching Study for Chlorpyrifos in Florida Citrus: Laboratory Report No. GH-C
             1870. Unpublished study prepared by Dow Chemical U.S.A.,  Ag Chemistry R&D
             Laboratories. 94 p.

40234801    Fontaine, D.; Tester, D. (1987) Chlorpyrifos-Photodegradation of Chlorpyrifos in
             the Vapor Phase: Laboratory Project ID  GH-C 1911.  Unpublished study prepared
             by ABC Laboratories in cooperation  with Dow Chemical U.S.A.  30 p.

40395201    Fontaine, D.; Wetters, J.; Weseloh, J.; et al. (1987) Field Dissipation and Leaching
             of Chlorpyrifos: Laboratory Project ID GHC-1957. Unpublished study by Dow
             Chemical U.S.A., Agricultural Chemistry R&D Laboratories.  115 p.

41747206    Batzer, F.; Fontaine, D.; White, F. (1990) Aqueous Photolysis  of Chlorpyrifos: Lab
             Project Number: GH-C 2417. Unpublished study by DowElanco. 189 p.

41887501    Valcore, D. (1991) Evaluation of Modeling Results for the Deposition of
             Chlorpyrifos from an Ultra Low Volume Application.  Unpublished study prepared
             by DowElanco Delivery Systems.  19 p.

41892801    McCall, P. (1987) Soil Adsorption Properties of Carbon  14-Chlorpyrifos: Lab
             Project No: GH-C 1971. Unpublished study by Dow Chemical Co.  U.S.A. 35 p.

41892802    Racke, K.; Robbins,  S. (1990) Factors Affecting the Degradation of
             3,5,6,-Trichloro-2-Pyridinol in Soil. Unpublished Study by DowElanco.  18 p.

42144911    Cranor, W. (1990) Aerobic Soil Metabolism of carbon 14 Chlorpyrifos: Lab Project
             Number: 36640. Unpublished study by Analytical Bio-Chemistry Labs, Inc. 46 p.
                                          197

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                            Chlorpyrifos Bibliography

42144912     Cranor, W. (1990) Aerobic Soil Metabolism of carbon 14 TCP: Lab Project
             Number: 36641. Unpublished study by Analytical Bio-Chemistry Labs, Inc. 44 p.

42493901     Racke, K.; Lubinski, R. (1992) Sorption of 3,5,6-Trichloro-2-Pyridinol in Four
             Soils: Lab Project Number: ENV91081. Unpublished study by DowElanco. 44 p.

42495403     Havens, P.; Kieatiwong, S.; Shepler, K. (1992) The Photochemical Degradation of
             Chlorpyrifos on Soil by Natural Sunlight: Lab Project Number: 254W-1: 254W:
             ENV90075. Unpublished study prepared by DowElanco. 108 p.

42495405     Hansen, S.; Woodburn, K.; Ball, T.; et al. (1992) Chlorpyrifos: Distribution and
             Metabolism in the Eastern Oyster, Crassostrea virginica: Lab Project Number:
             DECO-ES-2377. Unpublished study by The Dow Chemical Co.  50 p.

42495406     Thacker, J.; Strauss, K.; Smith, G. (1992) Chlorpyrifos: A Bioconcentration Test
             with the Eastern Oyster (Crassostrea virginica): Lab Project Number:  103 A-105:
             DSI/OYSBIO: ES-DR-0043-4946-8. Unpublished study prepared by Wildlife
             International Ltd.  67 p.

42874702     Robb, C.; Langer, W.  (1993) Determination of Chlorpyrifos in Soils by Gas
             Chromatography: Lab Project Number: ACR 91.5. Unpublished study prepared by
             DowElanco, North American Envir. Chem. Lab. 22 p.

42874703     Racke, K. (1991) Response to Review of Field Dissipation and Leaching Study for
             Chlorpyrifos in Florida Citrus Groves: Lab Project Number: RFB072993A.
             Unpublished study  prepared by DowElanco. 10 p.

42874704     Fontaine,  D. (1991) Response to Review of Field Dissipation and Leaching of
             Chlorpyrifos: Lab Project No: RFB072993. Unpublished by DowElanco. 26 p.

42924801     Racke, K.; Robb, C. (1993) Dissipation of Chlorpyrifos in Warm-Season Turfgrass
             and Fallow Soil in Florida: Lab Project Number: ENV90125.  Unpublished study
             prepared by Dow Elanco, North American Environmental Chemistry Lab.  187 p.

42924802     Racke, K.; Robb, C. (1993) Dissipation of Chlorpyrifos in Cool-Season Turfgrass
             and Fallow Soil in Indiana: Lab Project Number: ENV90126.  Unpublished study
             by Dow Elanco, North American Environmental Chemistry Lab.  186  p.

43210801     Thalacker, F. (1994) (Carbon 14)-Chlorpyrifos: Accumulation in Confined
             Rotational Crops (Screenhouse Study): Final Report: Lab Project Number: HWI
             6397-114: PM-046: MET92056. Unpublished study prepared by Hazleton
             Wisconsin, Inc. and Plant Sciences, Inc. 216 p.
                                         198

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                            Chlorpyrifos Bibliography

43760606    Valcore, D. (1995) Droplet Size Data for XRM-5318 Chlorpyrifos Formulation:
             Lab Project Number: FOR91121. Unpublished study prepared by New Mexico
             State University. 39 p.

43760607    Valcore, D. (1995) Droplet Size Data for Lorsban 4E Chlorpyrifos Formulation:
             Lab Project Number: FOR91122. Unpublished study prepared by New Mexico
             State University. 38 p.

43786902    Valcore, D. (1995) Droplet Size Data for LOCK-ON Chlorpyrifos Formulation:
             Lab Project Numbers: FOR91123: PASS A91-006. Unpublished study prepared by
             New Mexico State University, and DowElanco. 38 p.

43786903    Valcore, D. (1995) Aerial Spray Drift Field Study for Chlorpyrifos Formulations:
             Lab Project No: FOR92068. Unpublished study prepared by DowElanco. 142 p.

44083401    Kennard, L. (1996) Aerobic Aquatic Degradation of Chlorpyrifos in Flow Through
             System: Lab Project No: ENV95024. Unpublished study by DowElanco. 93 p.
Residue Chemistry MRID References

00025942    Miller, P.W. (1980) Residues of Chlorpyrifos and 3,5,6-Trichloro-2-pyridinol in
             Peanut Oil Fractions.  (Unpublished study received Jan 15, 1980 under 464-448;
             submitted by Dow Chemical U.S.A., Midland, Mich.; CDL:099201-D)

00033586    Davis, A.C.; Kuhr, R.J.; Helfman, G.; et al. (1980) Summary. Includes undated
             method entitled: 3,5,6-Trichloro-2-pyridinol on onions.  (Unpublished study
             received Jul 8, 1980 under OE2387; prepared in cooperation with Cornell Univ.,
             New York State Agricultural Experiment Station, Dept.  of Entomology and others,
             submitted by Dow Chemical U.S.A.; Midland, Mich.; CDL:099507-A)

00034031    Kiigemagi, U.; Inman, R.D.; Deinzer, M.L.; et al. (1979) Summary of Residue
             Trials. (Unpublished study received Jun 10, 1980 under OE2372; prepared in
             cooperation with Oregon State Univ., Depts. of Agricultural Chemistry and
             Entomology and others, submitted by Interregional Research Project No. 4, New
             Brunswick, N.J.; CDL:099448-A)

00037455    McKellar, R.L.; Dishburger, HJ. (1975) Determination of Residues of Chlorpyrifos
             and 3,5,6-Trichloro-2-pyridinol in Cottonseed, Gin Trash and Process Fractions
             following Multiple Treatments of Cotton Plants with Lorsban Insecticide.
             (Unpublished study received Feb 13, 1975 under 5G1595; submitted by Dow
             Chemical U.S.A., Midland, Mich.; CDL:094724-L)
                                         199

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                            Chlorpyrifos Bibliography

00037457     McKellar, R.L. (1974) Determination of Residues of 0,0-Diethyl 0-
             (3,5,6-trichloro-2-pyridyl) phosphorothioate in Cottonseed and Cotton Gin Trash by
             Gas Chromatography. Method ACR 74.4T dated May 13, 1974. (Unpublished
             study received Feb 13, 1975 under 5G1595; submitted by Dow Chemical U.S.A.,
             Midland, Mich.; CDL: 094724-N)

00037458     McKellar, R.L. (1973) Determination of Residues of 3,5,6-Trichloro-2-pyridinol in
             Lima and Snapbean Forage and Beans by Gas Chromatography. Method ACR
             71.19R dated Sep 27, 1973.  (Unpublished study received Feb 13, 1975 under
             5G1595; submitted by Dow Chemical U.S.A., Midland, Mich.; CDL:094724-O)

00039641     Wetters, J.H.; Dishburger, HJ. (1974) Residues of Chlorpyrifos and 3,5,6-
             Trichloro-2-pyridinol in Sugar Beets and Process Fractions Treated with Lorsban
             Insecticide: GH-C 729. Summary of studies 095171-M through 095171-O.
             (Unpublished study received Feb 11, 1976 under 6F1745; submitted by Dow
             Chemical U.S.A., Midland, Mich.; CDL:095171-L)

00039642     Wetters, J.H. (1973) Determination of Residues of 0,0-Diethyl 0-(3, 5,6-trichloro
             -2-pyridyl)phosphorothioate in Sugar Beets and Solid Process Fractions by Gas
             Chromatography. Method ACR 73.5 dated Dec 6, 1973. (Unpublished study
             received Feb 11, 1976 under 6F1745; submitted by Dow Chemical U.S.A.,
             Midland, Mich.; CDL:095171-M)

00039643     McKellar, R.L. (1972) Determination of Residues of 0,0-Diethyl 0- (3,5,6
             -trichloro-2-pyridyl)phosphorothioate in Snapbeans and Snapbean Forage by Gas
             Chromatography. Method ACR 72.15 dated Dec 4, 1972.  (Unpublished study
             received Feb 11, 1976 under 6F1745; submitted by Dow Chemical U.S.A.,
             Midland, Mich.; CDL: 095171-N)

00044555     Wetters, J.H.; Dishburger, HJ. (1975) Determination of Residues in Fruits and Nuts
             following Dormant Application of Lorsban Insecticide.  (Unpublished study
             received Apr 20, 1976 under 464-448; submitted by Dow Chemical U.S.A.,
             Midland, Mich.; CDL:095856-L)

00046785     Wetters, J.H.; Dishburger, HJ. (1976) Residues of Chlorpyrifos and 3,5,6-
             Trichloro-2-pyridinol in Sorghum Green Plant, Silage, Dry Plant, and Grain
             following Multiple Applications with Lorsban(R) Insecticide. (Unpublished study
             received May 15, 1980 under KS 80/6; submitted by Kansas, Dept. of Agriculture
             for Dow Chemical U.S.A., Midland, Mich.; CDL:242481-A)

00051798     Dow Chemical U.S.A. (19??) Proposed  Analytical Methods for Regulatory Control:
             Determination of Chlorpyrifos and Its Pyridinol Moiety in or on Bananas.
                                         200

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                            Chlorpyrifos Bibliography

             Summary of studies 093656-M through 093656-P. (Unpublished study received
             Mar 13, 1973 under 3F1370; CDL:093656-L)

00051801     Herman, J.L. (1972) Determination of Residues of 0,0-Diethyl 0-(3, 5,6-trichloro
             -2-pyridyl)phosphorothioate in Bananas by Gas Chromatography with Flame
             Photometric Detection. Method ACR 72.14 dated Nov 21, 1972. (Unpublished
             study received Mar 13, 1973 under 3F1370; submitted by Dow Chemical U.S.A.,
             Midland, Mich.; CDL:093656-O)

00058087     McKellar, R.L.; Dishburger, H. J. (1976) Determination of Residues of Chlorpyrifos
             and 3,5,6-Trichloro-2-pyridinol in Tissues of Cattle Receiving a  Single Treatment
             of Dursban Spot-On: Report No. GH-C-930.  (Unpublished study received Aug 12,
             1977 under unknown admin, no.; submitted by Dow Chemical U.S.A., Midland,
             Mich.;CDL:231282-E)

00058089     McKellar, R.L.; Dishburger, HJ. (1973) Determination of Residues of
             3,5,6-Trichloro-2-pyridinol in Bovine Tissues by Gas Chromatography: ACR
             70.19R. Method dated Aug 2, 1973.  (Unpublished study, Aug 12,  1977 under
             unknown date; by Dow Chemical U.S.A., Midland, Mich.;  CDL:231282-G)

00066724     Smith, G.N.; Watson, B.S.; Fischer, F.S. (1967) Investigations of Dursban
             insecticide. Uptake and translocation of 3,6C,O,-Diethyl-O-3, 5,6-trichloro-2-
             pyridyl phosphorothioate and 14C,O,O-DiethylO-3,5,6-trichloro- 2-pyridyl
             phosphorothioate by beans and corn.  Journal of Agricultural and Food Chemistry
             15(1):127-131. (Also In unpublished submission received Aug 28, 1972 under
             3F1306; submitted by Dow Chemical U.S.A., Midland, Mich.; CDL:092215-R)

00066725     Smith, G.N.; Watson, B.S.; Fischer, F.S. (1967) Investigations on Dursban
             insecticide. Metabolism of O,O-Diethyl O-3,5, 6,-trichloro-2-pyridyl
             phosphorothioate and 3,5,6-Trichloro-2-pyridinol in plants.  Journal of Agricultural
             and Food Chemistry 15(5):870-877.  (Also In unpublished submission, Aug 28,
             1972 under 3F1306; by Dow Chemical U.S.A., Midland, Mich.; CDL:092215-S)

00070509     McKellar, R.L.; Wetters, J.H.; Dishburger, H.J. (1972) Determination of Residues
             of Chlorpyrifos and 3,5,6-Trichloro-2-pyridinol in Green Forage, Grain and Stover
             of Corn following Surface Band and  Seed Furrow Applications of Dursban
             Insecticide: GH-C  530. (Unpublished study received Nov 12, 1980 under 464-523;
             submitted by Dow Chemical U.S.A.,  Midland, Mich.; CDL:244439-A)

00072657     Bauriedel, W.R.; Miller, J.H. (1980) The Metabolic Fate of 14|iC- Chlorpyrifos
             Applied to an Apple Tree: GH-C 1397.  (Unpublished study, Mar 6, 1981 under
             464-448; by Dow Chemical U.S.A., Midland, Mich.; CDL:099939-A)
                                         201

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                            Chlorpyrifos Bibliography

00072660    Bauriedel, W.R.; Miller, J.H. (1981) The Metabolic Fate of 14|iC- Chlorpyrifos
             Applied Topically to Soybeans: GH-C 1414. (Unpublished study received Mar 6,
             1981 under 464-448; by Dow Chemical U.S.A., Midland, Mich.; CDL:099942-A)

00077055    Glas, R.D. (1981) The Metabolic Fate of 14C-Chlorpyrifos Fed to Lactating Goats:
             GH-C 1408 R.  (Unpublished study received Jul  1, 1981 under 9F2221; submitted
             by Dow Chemical Co., Midland, Mich.; CDL:070176-A)

00077120    Interregional Research Project Number 4 (1981) The Results of Tests on the
             Amount of Chlorpyrifos Residues Remaining in or on Cherries Including a
             Description of the Analytical Method Used. (Compilation; unpublished study
             received Jun  5, 1981 under 1E2529; CDL:070135-A)

00078962    Norton, E.J.;  Wetters, J.H.; Miller, P.W. (1981) Residues of Chlorpyrifos and
             3,5,6-Trichloro-2-pyridinol in Field Corn following Multiple Applications of
             Lorsban Insecticides.  (Unpublished study received Jul 8, 1981 under 464-448;
             submitted by Dow Chemical U.S.A., Midland, Mich.; CDL:070208-L)

00083840    Dow Chemical U.S.A. (1979) Results of Tests on the Amount of Residue
             Remaining, Including a Description of the Analytical Method: Chlorpyrifos.
             (Unpublished study received Mar 3, 1979 under 464-448; CDL:098038-I)

00084266    Wetters, J.H.; Norton, E.J.; Miller, P.W. (1981) Residues of Chlorpyrifos and
             3,5,6-Trichloro-2-pyridinol in Corn Process Fractions following Treatment of Grain
             with Lorsban 4E Insecticide: GH-C 1465. (Unpublished study received Sep 9, 1981
             under 1F2544; by Dow Chemical Co., Indianapolis, Ind.; CDL:070316-A)

00084326    Wetters, J.H. (1980) Residues of Chlorpyrifos and 3,5,6-Trichloro-2-pyridinol in
             Whole Citrus and Citrus Process Fractions following Foliar Applications of
             Lorsban 4E Insecticide. (Unpublished study received Sep 10, 1981 under 1F2575;
             submitted by Dow Chemical Co., Indianapolis, Ind.; CDL:070368-E)

00084330    Wetters, J.H. (1973) Determination of Residues of O,O-Diethyl O-(3,5,6-
             Trichloro-2-pyridyl) phosphorothioate in Sugar Beet Liquid Process Fractions by
             Gas Chromatography. Method ACR 73.6 dated Dec 7,  1973. (Unpublished study
             received Sep 10, 1981 under 1F2575; submitted by Dow Chemical Co.,
             Indianapolis, Ind.; CDL:070368-N)

00084331    Wetters, J.H. (1975) Determination of Residues of O,O-Diethyl O- (3,5,6-
             Trichloro-2-pyridyl) phosphorothioate in Sweet Potatoes by Gas Chromatography.
             Method ACR 75.4 dated Jul 29,  1975. (Unpublished study received Sep 10, 1981
             under 1F2575; by Dow Chemical Co., Indianapolis, Ind.; CDL:070368-O)
                                         202

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                            Chlorpyrifos Bibliography

00084845     Miller, P.W. (1980) Residues of Chlorpyrifos and 3,5,6-Trichloro-2-pyridinol in
             Sunflower Seed and Forage from Multiple Applications of Lorsban Insecticides.
             (Unpublished study received Oct 21, 1981 under 2F2588; submitted by Dow
             Chemical U.S.A., Midland, Mich.; CDL:070408-O)

00084846     Miller, P.W. (1981) Residues of Chlorpyrifos and 3,5,6-Trichloro-2-pyridinol in
             Sunflower Seed and Process Fractions from Sunflowers Treated with Lorsban
             Insecticides. (Unpublished study received Oct 21, 1981 under 2F2588; submitted
             by Dow Chemical U.S.A., Midland, Mich.; CDL:070408-P)

00085785     Interregional Research Project Number 4 (1981) The Results of Tests on the
             Amount of Chlorpyrifos Residues Remaining in or on Grapes Including a
             Description of the Analytical Method Used.  (Compi lation; unpublished study
             received Oct 19, 1981 under 2E2584; CDL:070420-A)

00088978     Miller, P.W. (1981) Determination of Residues of Chlorpyrifos and 3,5,6-
             Trichloro-2-pyridinol in Apple Process Fractions: GH-C 1488.  (Unpublished study
             received Dec 2, 1981 under 2H5331; submitted by Dow Chemical Co.,
             Indianapolis, Ind.; CDL:070576-A)

00090562     McKellar, R.L.; Morgan, R.W.; Dishburger, H.J.; et al. (1973) Residue Study:
             Determination of Chlorpyrifos in Food from Food Handling Establishments Treated
             with Dursban Insecticide: GH-C 678. (Unpublished study received Mar  11, 1975
             under 5H5080; by Dow Chemical U.S.A., Midland, Mich.; CDL: 221800-J)

00090563     McKellar, R.L.; Dishburger, H.J.; Porteous, D.J.; et al. (1974) Residue Study:
             Determination of Chlorpyrifos in Human Food Resulting from Treatment of Food
             Handling  Establishments with Dursban 2E Insecticide: GH-C 773R.  (Unpublished
             study received Mar 11,  1975 under 5H5080;  submitted by Dow Chemical U.S.A.,
             Midland, Mich.; CDL:221800-K)

00094088     Interregional Research Project Number 4 (1980) The Results of Tests on the
             Amount of Chlorpyrifos Residues Remaining in or on Asparagus Including a
             Description of the Analytical Method Used. Includes methods dated Jul 12, 1978.
             (Unpublished study received Feb 3, 1982 under 2E2644; CDL:070655-A)

00095179     Dow Chemical Company (1972) Results of Tests on the Amount of Residue
             Remaining, Including a Description of the Analytical Method: Dursban.  Includes
             method ACR 58.5 dated Aug  1, 1958; method ACR 59.3R dated May 19, 1961;
             method ACR 70.19 dated Dec 14, 1970; and others. (Compilation; unpublished
             study, including published data, received Aug 28, 1972 under 3F1306; CDL:
             092216-A; 092217, 092218)
                                         203

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                            Chlorpyrifos Bibliography

00095201     Hunt, L.M.; Gilbert, B.N.; Schlinke, J.C. (1969) Rapid gas chromatographic
             method for analysis of 0,0-diethyl-O-3,5-6-trichloro-2-pyridy/ phosphorothioate
             (Dursban) in turkey and chicken tissues.  Journal of Agricultural and Food
             Chemistry 17(6): 1166-1167.  (Also In submission received Aug 28, 1972 under
             3F1306; submitted by Dow Chemical Co., Indianapolis, Ind.; CDL:092219-J)

00095216     Dow Chemical U.S.A. (1973) Results of Tests on the Amount of Residue
             Remaining,  Including a Description of the Analytical Method: Chlorpyrifos.
             Includes method ACR 72.15 dated Dec 4, 1972; method ACR 71.19R dated Sep 27,
             1973; method 72.9 dated Dec 28, 1972; and others. (Compilation; unpublished
             study received Nov 29, 1973 under 4F1445; CDL:093852-E)

00095227     Dow Chemical U.S.A. (1975) Results of Tests on the Amount of Residue
             Remaining,  Including a Description of the Analytical Method: Chlorpyrifos.
             Includes method ACR 75.4 dated Jul 29, 1975. (Compilation; unpublished study
             received May 12, 1976 under 464-404; CDL:095509-D)

00095249     Wetters, J.H.; Miller, P.W. (1978) Residues of Chlorpyrifos and 3,5,6-Trichloro
             -2-pyridinol in Grain and Milling Fractions Following Multiple Applications of
             Lorsban 4E  Insecticide to Sorghum. (Unpublished study received Jun 7, 1978
             under 464-448; by Dow Chemical U.S.A., Midland, Mich.; CDL:097128-A)

00095251     Dow Chemical U.S.A. (1977) Results of Tests on the Amount of Residue
             Remaining,  Including a Description of the Analytical Method: oChlorpyrifos and
             Its Metabolite TCP. Includes methods ACR 73.5 dated Dec 6, 1973, ACR 73.5.S3
             dated May 16, 1978, ACR 71.19R dated  Sep 27,  1973. (Compilation; unpublished
             study received Jun 21, 1978 under 8E2092; submitted by Dow Chemical U.S.A.,
             Midland, Mich.; CDL:097157-B)

00095259     Interregional Research Project Number 4 (1976) Results of Tests Concerning the
             Amount of Residues of Chlorpyrifos, O,O-Diethyl O-(3,5,6-Trichloro-2-pyridyl)
             Phosphorothioate and Its Metabolite, 3,5,6-Trichloro-2-pyridinol in or on Radishes,
             Rutabaga Roots, Turnip Roots, and Turnip Tops, Including a Description of the
             Analytical Method Used. (Compilation;  unpublished study received Jan 5, 1978
             under 8E2038; CDL:097451-A)

00095260     Dow Chemical U.S.A. (1978) Results of Tests on the Amount of Residue
             Remaining,  Including a Description of the Analytical Method: Chlorpyrifos.
             Includes methods ACR 73.5 dated Dec 6, 1973, ACR 73.5.SI dated May 21, 1976,
             ACR 71.19R dated Sep 27, 1973.  (Compilation;  unpublished study received Jan
             29, 1979 under 464-EX-56; CDL:097781-D)
                                         204

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                            Chlorpyrifos Bibliography

00095263     Miller, P.W. (1979) Residues of Chlorpyrifos and 3,5,6-trichloro-2-pyridinol in
             Peanut Fractions. (Unpublished study received Jun 5, 1979 under 464-448;
             submitted by Dow Chemical U.S.A., Midland, Mich.; CDL:098335-A)

00095264     Dow Chemical U.S.A. (1978) Results of Tests on the Amount of Residue
             Remaining, Including a Description of the Analytical Method: 6Chlorpyrifos|.
             Includes method ACR 73.5 dated Dec 6, 1973; method ACR 71.19 dated Sep 27,
             1973; method ACR 72.15 dated Dec 4,  1972; and Others.  (Compilation;
             unpublished study received Jun 13, 1979 under 464-552; CDL:098337-A)

00095270     Dow Chemical U.S.A. (1979) Results of Tests on the Amount of Residue
             Remaining, Including a Description of the Analytical Method: Chlorpyrifos.
             Includes method ACR 73.5 dated Dec 6, 1973 and method ACR 71.19R dated Sep
             27, 1973. (Compilation; unpublished study, including GH-C, 1224, received Sep
             24, 1979 under 464-448 CDL:099023-P)

00095271     Interregional Research Project Number 4 (1979)  Chlorpyrifos: Residue Tolerance
             Petition—Strawberries.  (Compilation; unpublished study received Oct 16, 1979
             under OE2283; CDL:099065-A)

00095273     Interregional Research Project Number 4 (1976)  Results of Tests Concerning the
             Amount of Residues of Chlorpyrifos and Its Metabolite, 3,5,6-Trichloro-2-
             pyridinol in or on Broccoli, Brussels Sprouts, Cabbage, and Cauliflower, Including
             a Description of the Analytical Method Used.  (Compilation; unpublished study
             received Sep 29, 1977 under 7E2010; CDL:099111-A)

00095373     McKellar, R.L.; Dishburger, H. J. (1974) Determination of Residues of Chlorpyrifos
             and 3,5,6-Trichloro-2-pyridinol in Cottonseed and Gin Trash Following Multiple
             Treatments of Cotton Plants With Lorsban Insecticide: GH-C 739. (Unpublished
             study received Sep 16, 1976 under 464-448; submitted by Dow Chemical U.S.A.,
             Midland, Mich.; CDL:228192-D)

00095374     Wetters, J.H.; Dishburger, HJ. (1975) Residues of Chlorpyrifos and
             3,5,6-Trichloro-2-pyridinol in Tomatoes Following Multiple Foliar Appliation with
             Lorsban(TM) Insecticide : GH-C 829. (Unpublished study received Sep 16, 1976
             under 464-448; by Dow Chemical U.S.A., Midland, Mich.; CDL:228192-E)

00095383     Wetters, J.H. (1972) Determination of Residues of O-O-Diethyl O-
             (3,5,6-Trichloro-2-pyridyl) Phosphorothioate in Swine Tissues by Gas
             Chromatography with Flame Photometric Detection. Method ACR 72.1 dated Jan
             6, 1972. (Unpublished  study received Aug 11, 1977 under 26693-2; prepared by
             Dow Chemical U.S.A.,  submitted by Positive Formulators, Inc., Tucson, Ariz.;
             CDL:231274-B)
                                         205

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                            Chlorpyrifos Bibliography

00095387     Dow Chemical U.S.A. (1976) Determination of Residues of Dursban 44
             (Chlorpyrifos) Insecticide in Tissues of Cattle|. Includes methods ACR 72.3 dated
             Feb 14, 1972, ACR 70.19R dated Aug 2, 1973 and ACR 72.1 dated Jan 6, 1972.
             (Compilation; unpublished study, Aug 12, 1977 under 464-EX-52; CDL:233132-C)

00095436     Claborn, H.V.; Mann, H.D.; Oehler, D.D. (1968) Dursban(R) determination in milk
             and body tissues of cattle. Journal of the Association of Official Analytical
             Chemists 51(6): 1243-1245. (Also In unpublished submission, Mar 20, 1978 under
             KS 78/4; by state of Kansas for Y-Tex Corp., Cody, Wyo.; CDL:236565-L)

00095438     Y-Tex Corporation (1977) Tissue Residue Study: Chlorpyrifos in Cattle.
             (Compilation; unpublished study received Mar 20, 1978 under KS 78/4; submitted
             by state of Kansas for Y-Tex; CDL: 236565-P)

00098580     Interregional Research Project Number 4 (1980) The Results of Tests on the
             Amount of Chlorpyrifos Residues Remaining in or on Figs, Including a Description
             of the Analytical Method Used. (Compilation; unpublished study received Apr 12,
             1982 under 2E2668; CDL:070783-A)

00101566     Dow Chemical U.S.A. (1982) Results of Tests on the Amount of Residue
             Remaining, Including a Description of the Analytical Method: Chlorpyrifos.
             (Compilation; unpublished study received May 14, 1982 under 2F2684;
             CDL:070855-C)

00108813     Interregional Research Project No. 4 (1981) The Results of Tests on the Amount of
             Chlorpyrifos Residues Remaining in or on Cranberries Including a Description of
             the Analytical Method Used. (Compilation; unpublished study received May 11,
             1982 under 2E2682; CDL:070847-A)

00115260     Dow Chemical Co. (1982) Results of Tests on the Amount of Residue Remaining,
             Including a Description of the Analytical Method: Chlorpyrifos.  (Compilation;
             unpublished study received Oct 1, 1982 under 3E2766; CDL:071167-B)

00116675     Dow Chemical U.S.A. (1982) Results of Tests on the Amount of Residue
             Remaining, Including a Description of the Analytical Method: Chlorpyrifos.
             (Compilation; unpublished study, Oct 26, 1982 under 464-552; CDL:071198-C)

00125686     Dow Chemical U.S.A. (1982) Chlorpyrifos: Residues in Alfalfa and Other Subjects.
             (Compilation; unpublished study, Feb 1, 1983 under 464-448;  CDL:249449-A)

00126713     Dow Chemical U.S.A. (1983) Results of Tests on the Amount of Residue
             Remaining, Including a Description of the Analytical Method: Chlorpyrifos.
             (Compilation; unpublished study, Apr 12, 1983 under 464-448; CDL:071517-B)
                                         206

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                             Chlorpyrifos Bibliography

00129295     Interregional Research Project No. 4 (1982) The Results of Tests on the Amount of
             Chlorpyrifos Residues Remaining in or on Mushrooms Including a Description of
             the Analytical Method Used. (Compilation; unpublished study received May 5,
             1983 under 3E2886; CDL:071593-A)

00131864     Miller, P. (1983) Residues of Chlorpyrifos and 3,5,6-Trichloro-2-Pyridinol in
             Tomatoes Receiving Multiple Foliar Applications of Lorsban 4E Insecticide: GH-C
             1641. (Unpublished study received Sep 1, 1983  under 464-448;  submitted by Dow
             Chemical U.S.A., Midland, MI; CDL:251158-A)

00132786     Dow Chemical U.S.A. (1983) Results of Tests on the Amount of Residue
             Remaining, Including a Description of the Analytical Method: Chlorpyrifos.
             (Compilation; unpublished study, Nov 25, 1983 under 464-552; CDL:072160-C)

00134499     Wetters, J. (1983) Letter sent to R. Bischoff dated Oct 17, 1983:  Residues of
             Chlorpyrifos and 3,5,6-Trichloro-2-pyridinol in Grapes, Raisins, and Raisin Trash.
             (Unpublished study received Oct 28, 1983 under 3F2872; submitted by Dow
             Chemical U.S.A., Midland, MI; CDL:072086-A)

00134720     Dow Chemical U.S.A. (1979) Results of Tests on the Amount of Residue
             Remaining, Including a Description of the Analytical Method: Chlorpyrifos.
             (Compilation; unpublished study, Oct 18, 1979 under 464-448; CDL:099038-B)

00141725     Wetters, J. (1984) Letter sent to R. Bischoff dated Apr 26, 1984: Residues of
             Chlorpyrifos and 3,5,6-trichloro-2-pyridinol  on or in whole oranges. Prepared by
             Dow Chemical U.S.A. 9 p.

00148881     Wetters, J. (1985) Letter sent to R.F. Bischoff dated March 25, 1985: Residues  of
             Chlorpyrifos and 3, 5,  6-trichloro-2-pyridinol on  or in alfalfa green forage and hay.
             Prepared by Dow Chemical USA.  9 p.

00154019     Braun, H.; Ritcey, G.; Frank, R.; et al. (1980) Dissipation rates of insecticides in six
             minor vegetable crops grown on organic soils in Ontario, Canada. Pest. Sci.
             11(6):605-616.

00154734     Dow Chemical U.S.A. (1985) Residue Chem: Chlorpyrifos. Unpublished. 317 p.

00155578     Miller, P.; McKellar, R. (1986) Residues of Chlorpyrifos and 3,5,6- Trichloro
             -2-pyridinol in Wheat following Aerial or Ground Applications of Lorsban 4E
             Insecticide: GH-C 1790. Unpublished study by Dow Chemical U.S.A. 31 p.
                                          207

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                             Chlorpyrifos Bibliography

00155579    McKellar, R. (1986) Letter sent to R. Bischoff dated Jan 30, 1986: Plum/prune data:
             Residues of chlorpyrifos and 3,5,6-trichloro-2-pyridinol. Prepared by Dow
             Chemical U.S.A. 5 p.

00155580    Miller, P.; Wetters, I; McKellar, R.; et al. (1986) Residues of Chlorpyrifos and
             3,5,6-Trichloro-2-pyridinol in Broccoli, Cabbage and Mustard Greens following
             Multiple Applications of Lorsban and/or Dursban Insecticides: GH-C 1788.
             Unpublished study prepared by Dow Chemical U.S.A. 52 p.

00157541    Bauriedel, W.; Miller, J. (1986) The Metabolic Fate of Carbon 14-Chlorpyrifos
             Applied to Field Corn at Planting (Soil Application) and in Mid-season (Foliar
             Application): GH-C 1807.  Unpublished study by Dow Chemical U.S.A. 36 p.

00157542    Bauriedel, W. (1986) The Early Fate of Carbon  14-chlorpyrifos Applied to Leaf
             Surfaces of Corn, Soybean, and Sugar Beet: GH-C  1808. Unpublished study
             prepared by Dow Chemical U.S.A. 30 p.

00157543    Bauriedel, W.; Miller, J. (1986) The Metabolic Fate of Carbon 14-chlorpyrifos
             Applied to Sugar Beets at Planting (Soil Application and in Mid-season (Foliar
             Application): GH-C 1809.  Unpublished study by Dow Chemical U.S.A. 31 p.

00157713    Wetters, J.; McKellar, R.; Ordiway, T. (1986) Residues of Chlorpyrifos and
             3,5,6-Trichloro-2-pyridinol on or in Sweet Corn Ears and Green Forage following
             Multiple Foliar Applications of Lorsban SOW or Lorsban 4E Insecticides: GH-C
             1797. Unpublished study prepared by Dow Chemical U.S.A. 33 p.

00157909    Interregional Reserach Project No. 4 (1985) The results of Tests on Amount of
             Chlorpyrifos Residues Remaining in or  on Leeks Including a Description of the
             Analytical Method Used. Unpublished  compilation.  56 p.

00158566    McKellar, R.; Ordiway, T. (1986) Residues of Chlorpyrifos and 3,5,6-Trichloro
             -2-pyridinol in Broccoli, Brussels Sprouts, Cabbage, and Cauliflower following
             Two Applications of Lorsban 4E Insecticide: Report No. GH-C 1802. Unpublished
             study prepared by Dow Chemical USA.  19 p.

00158567    McKellar, R.; Ordiway, T. (1986) Residues of Chlorpyrifos and 3,5,6-Trichloro -2-
             pyridinol on or in Alfalfa Seed following an Application of Lorsban 4E Insecticide:
             Report No. GH-C 1803. Unpublished study by Dow Chemical USA.  10 p.

00158568    Wetters, J. (1986) Residues of Chlorpyrifos and 3,5,6-Trichloro-2-pyridinol on or
             in Alfalfa Green Forage and Hay after Foliar Applications of Lorsban 4E
             Insecticide: Report No. GH-C  1805. Unpublished study by  Dow Chemical USA.
             16 p.
                                          208

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                             Chlorpyrifos Bibliography

00158569    Miller, P.; McKellar, R. (1986) Residues of Chlorpyrifos and 3,5,6-Trichloro
             -2-Pyridinol in Sorghum Green Forage, Fodder and Grain following at Plant and
             Post Plant Applications of Lorsban 15G and Lorsban 4E Insecticides: Report No.
             GH-C 1813. Unpublished study prepared by Dow Chemical USA. 17 p.

00161743    Puhl, R. (1986) Metabolism Study of Carbon 14-chlorpyrifos in Laying Hens: Final
             Report: Study No. 6148-102.  Unpublished study prepared by Hazleton
             Laboratories America, Inc.  108 p.

00162109    Interregional Research Proj ect No. 4 (1986) The Results of Tests on the Amount of
             Chlorpyrifos Residues Remaining in or on Dates Including a Description of the
             Analytical Method Used. Unpublished compilation. 52 p.

00164187    Interregional Research Proj ect No. 4 (1986) The Results of Tests of the Amount of
             Chlorpyrifos Residues Remaining in or on Blueberry Including a Description of the
             Analytical Method Used: GHC-1832; 68-01-6670.  Unpublished  compilation. 44 p.

40131301    Doom, J. (1986) Determination of Residues of Chlorpyrifos and 3,5,6-Trichloro
             -2-pyridinol in or on Cabbage Following Two Applications of Lorsban 4E: Lab ID:
             GH-C 1847. Unpublished study by Dow Chemical U.S.A. 16 p.

40131302    Wetters, J. (1987) Residues of Chlorpyrifos and 3,5,6-Trichloro-2- pyridinol on or
             in Strawberries Treated by Preplant and/or Following Two Foliar Applications of
             Lorsban 4E Insecticide: Lab Project ID: GH-C 1871. Unpublished  study prepared
             by Dow Chemical U.S.A.  19 p.

40131303    Wetters, J. (1987) Residues of Chlorpyrifos and 3,5,6-Trichloro-2-pyridinol in or
             on Cottonseed Following Five Foliar Applications of Lorsban 4E Insecticide: Lab
             Project ID: GH-C 1993. Unpublished study by Dow Chemical U.S.A. 16 p.

40265201    Levan, L.; McCall, P. (1987) A Study of Pyrolysis of 3,5,6-Trichloro-2-pyridinol in
             Cigarette Tobacco: Lab. project. ID HLA 6015-312. Unpublished study prepared by
             Hazleton Laboratories America, Inc. 44 p.

40288501    Wetters, J.; Markle, G. (1987) Chlorpyrifos-Residues of Chlorpyrifos and
             3,5,6-Trichloro-2-pyridinol in or on Caneberries Receiving Multiple Foliar
             Applications of Lorsban SOW Insecticide: Protocol 9-83 and 3-84. Unpublished
             compilation prepared by Dow Chemical U.S.A.  46 p.

40638801    McCall, P. (1988) Response to EPA Review of Goat Metabolism Data Submitted to
             Support Separation of TCP from the Tolerance Expression for Chlorpyrifos.
             Unpublished study prepared by Dow Chemical U.S.A.  lip.
                                          209

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                            Chlorpyrifos Bibliography

40638802     McCall, P. (1988) Response to EPA Review of Plant Metabolism Data Submitted to
             Support Separation of TCP from the Tolerance Expression for Chlorpyrifos.
             Unpublished study prepared by Dow Chemical Co. 9 p.

41424401     Oliver, G. (1990) Summary of Previously Submitted Residue Data to Support the
             Use of Chloryrifos on Walnuts. Unpublished study by DowElanco. 27 p.

41739001     Duebelbeeis, D. (1990) Determination of Chlorpyrifos And 3,5,6-Trichloro-2-
             Pyridinol Residues in Alfalfa Green Forage And Cured Hay Receiving A Postplant
             Application of Lorsban 2E Insecticide: Lab Project Number: GH-C 2293: 86098.
             Unpublished study prepared by DowElanco. 37 p.

41829007     Lewer, P. (1990) Reinvestigation of the Nature of the Residues in Forage from
             ocarbon 14|-Chlorpyrifos-Treated Field Corn: Lab Project Number: GH-C/2291.
             Unpublished study prepared by DowElanco. 60 p.

42245904     Nugent, P.; Schotts, B. (1991) Residues of Chlorpyrifos in Sweet Corn Ears and
             Forage Following Multiple Applications  of Lorsban 4E: Lab Project Number:
             90029. Unpublished  study prepared by DowElanco. 33 p.

42245905     Robb, C. (1991) Determination of Chlorpyrifos Residues  in Sorghum Grain and
             Fodder: Lab Project Number: 90025. Unpublished study by DowElanco. 30 p.

42245906     Robb, C. (1991) Determination of Residues of Chlorpyrifos in Sunflowers: Lab
             Project Number:  90026.  Unpublished study prepared by DowElanco.  21 p.

42245907     Nugent, P.; Schotts, B. (1992) Residues of Chlorpyrifos in Snap Bean Hay
             Following a Preplant  Application of Lorsban 50-SL to the Seeds:  Lab  Project
             Number: 90027.  Unpublished study prepared by DowElanco. 26 p.

42542701     Robb, C.; Stafford, I; Ostrander, J. (1992) Residues of Chlorpyrifos in Milk and
             Cream from Dairy Cows Wearing Chlorpyrifos-impregnated Plastic Ear Tags: Lab
             Project Number:  RES92025.  Unpublished study by DowElanco.  123  p.

42645401     Biehn, W. (1993) Chlorpyrifos: Magnitude of Residue on Sugarcane: Lab Project
             Number: 3239: 87124: 16-5258. Unpublished study prepared by Hawaiian Sugar
             Planters Assoc. 403 p.

42649001     Leavitt, R.; Markle, G.; Wells, A.  (1983) Chlorpyrifos: Magnitude of Residue on
             Onions (Green and Bulb) Michigan: Lab  Project Number: 452: 5186.  Unpublished
             study by Michigan State  University, IR-4 North Central Region 30 p.
                                         210

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                            Chlorpyrifos Bibliography

42649002     Robb, C.; Schotts, B.; Ostrander, J.  (1993) Determination of Residues of
             Chlorpyrifos in Processed Fractions of Corn: Lab Project Number: 90030.
             Unpublished study by DowElanco and Texas A&M University.  212 p.

43181401     Turner, L.; Phillips, A.; Schotts, B. (1994) Magnitude of the Residue of
             Chlorpyrifos in Whole Seed and Hulls From the Processing of Sunflowers: Lab
             Project Number: RES93013. Unpublished study prepared by Texas A&M Univ.
             System, Food Protein Research & Development Center and DowElanco, American
             Environmental Chemistry Lab. 80 p.

43445601     Catta-Preta, R.; Rampazzo, P. (1994) Residues of Chlorpyrifos in Pears After
             Treatment with LORSBAN 50W-Chile, 1993-1994: Lab Project Numbers: EC
             020/93: LARP93006: GHB-P 211. Unpublished study prepared by DowElanco
             Latin America. 52 p.
                                         211

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Chlorpyrifos Bibliography
          212

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Appendix E. Generic Data Call-In
              213

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Appendix E. Generic Data Call-in

       See the following table for a list of generic data requirements. Note that a complete Data
Call-In (DCI), with all pertinent instructions, is being sent to registrants under separate cover.
The following documents are part of the Generic Data Call-in.

       DCI Response

       Requirements Status and Registrant's Response

       Footnotes and Key Definitions for Guideline Requirements
                                           214

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Appendix F. Product Specific Data Call-In
                  215

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Appendix F.         Product Specific Data Call-In

       See attached table for a list of product-specific data requirements. Note that a complete
Data Call-In (DCI), with all pertinent instructions, is being sent to registrants under separate cover.
                                            216

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Appendix G.  EPA's Batching of Chlorpyrifos Products for Meeting Acute Toxicity
             Data Requirements for Reregistration
                                  217

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Appendix G.  EPA'S BATCHING OF CHLORPYRIFOS 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 reregi strati on of products containing Chlorpyrifos as an 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 the Agency is not describing batched
products as "substantially similar" since some products with in 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.  Notwithstanding the batching process, the Agency reserves the right to
require, at any time, acute toxicity data for an individual product should 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 in a batch, or to generate all the required acute
toxicological studies for each of their own products.  If the 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 the
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 to-days 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, the
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 the registrant supplies the data to
support a batch of products, he/she must select the 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 ). If a registrant depends on another's data, he/she must choose


                                            218

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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.

       Two hundred twenty four products were found which contain Chlorpyrifos as the active
ingredient. These products have been placed into 27 batches and a "No Batch" category in
accordance with the active and inert ingredients and type of formulation.  Please note that this
batching scheme may not apply to products with CSFs that have been revised after generation of
this document.
Batch 1









EPA Reg. No.
4787-38
4787-40
4748-41
11678-58
34704-826
42519-23
62719-353
62719-355
70907-19
Percent active ingredient
99.7
98.5
97.0
97.0
99.0
97.0
97.0
99.0
99.3
Formulation Type
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Batch 2








EPA Reg. No.
1812-446
4787-37
4787-39
51036-350
62719-77
62719-349
62719-351
70907-17
Percent active ingredient
62.5
62.2
61.9
61.5
62.5
62.5
62.5
60.6
Formulation Type
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid
                                           219

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Batch 3



EPA Reg. No.
7501-29
34704-693
62719-38
Percent active ingredient
50.0
50.0
50.0
Formulation Type
Solid
Solid
Solid
Batch 4







EPA Reg. No.
62719-39
62719-68
62719-72
62719-221
62719-255
62719-352
70907-8
Percent active ingredient
50.0
50.0
50.0
50.0
50.0
50.0
50.0
Formulation Type
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Batch 5









EPA Reg. No.
655-499
829-280
1022-543
1386-649
34704-66
51036-122
51036-154
60061-82
60061-108
Percent active ingredient
44.8
44.9
44.9
44.9
41.2
42.8
44.7
44.9
44.9
Formulation Type
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid
Batch 6




EPA Reg. No.
10163-158
19713-504
19713-518
19713-520
Percent active ingredient
40.7
45.0
44.9
40.2
Formulation Type
Liquid
Liquid
Liquid
Liquid
220

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51036-216
51036-291
51036-294
62719-382
66222-3
66222-17
66222-19
67760-7
67760-27
67760-28
70907-3
70904-4
70907-7
70907-13
70907-18
44.7
44.7
44.7
42.0
44.9
44.9
40.7
44.6
44.2
44.2
45.0
45.0
45.0
45.0
45.0
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid
Batch 7









EPA Reg. No.
19713-300
42519-19
42519-21
62719-11
62719-35
62719-69
62719-220
62719-245
62719-254
Percent active ingredient
44.9
44.9
44.9
44.9
44.9
44.9
44.9
44.9
44.9
Formulation Type
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid
Batch 8


EPA Reg. No.
655-466
829-279
Percent active ingredient
24.6
24.7
Formulation Type
Liquid
Liquid
221

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28293-200
51036-152
66222-5
66222-6
24.1
24.6
24.5
24.9
Liquid
Liquid
Liquid
Liquid
Batch 9





EPA Reg. No.
42519-20
51036-257
62719-65
67760-6
67760-31
Percent active ingredient
24.8
24.6
24.8
24.7
24.7
Formulation Type
Liquid
Liquid
Liquid
Liquid
Liquid
Batch 10


EPA Reg. No.
62719-166
62719-167
Percent active ingredient
23.5
23.5
Formulation Type
Liquid
Liquid
Batch 11


EPA Reg. No.
499-367
499-419
Percent active ingredient
20.0
20.0
Formulation Type
Liquid
Liquid
Batch 12



EPA Reg. No.
10350-22
62719-88
62719-364
Percent active ingredient
20.0
20.0
20.0
Formulation Type
Liquid
Liquid
Liquid
Batch 13



EPA Reg. No.
19713-505
62719-383
70907-5
Percent active ingredient
15.0
15.0
15.0
Formulation Type
Solid
Solid
Solid
222

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Batch 14


EPA Reg. No.
19713-521
66222-18
Percent active ingredient
15.0
15.0
Formulation Type
Solid
Solid
Batch 15




EPA Reg. No.
829-290
1386-615
28293-210
62719-380
Percent active ingredient
12.9
12.6
12.6
12.6
Formulation Type
Liquid
Liquid
Liquid
Liquid
Batch 16














EPA Reg. No.
655-764
769-825
1386-653
8378-34
9198-39
9198-127
10404-15
28293-201
32802-22
34704-423
51036-247
51036-259
51036-264
53883-52
Percent active ingredient
2.32
2.5
2.0
2.32
2.5
2.32
2.32
2.5
2.32
2.0
2.5
2.32
2.32
2.5
Formulation Type
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Batch 17


EPA Reg. No.
829-292
62719-276
Percent active ingredient
2.5
2.5
Formulation Type
Solid
Solid
223

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Batch 18




















EPA Reg. No.
769-679
769-726
829-291
1386-652
8329-26
8378-33
8378-46
9198-68
9198-132
9198-167
10404-67
10404-81
28293-202
32802-20
32802-49
34704-448
51036-153
51036-220
62719-54
62719-210
Percent active ingredient
1.0
1.0
1.0
1.0
1.0
1.14
1.0
1.0
0.97
1.34
1.0
0.97
1.0
1.14
1.0
1.0
1.0
1.0
1.0
1.0
Formulation Type
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Batch 19






EPA Reg. No.
8378-26
8378-27
9198-32
10404-27
32802-21
62719-271
Percent active ingredient
0.92
1.14
0.92
0.97
1.14
1.0
Formulation Type
Solid
Solid
Solid
Solid
Solid
Solid
224

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Batch 20




















EPA Reg. No.
655-766
829-223
829-272
2724-487
4822-153
4822-335
4822-411
8329-23
8378-28
8848-61
9198-137
9688-67
32802-19
32802-39
34704-55
47006-5
51036-117
51036-263
53883-48
62719-14
Percent active ingredient
0.5
0.5
0.5
0.5
0.5
0.03
0.528
0.5
0.5
0.5
0.5
0.50
0.7
0.5
0.5
0.5
0.5
0.5
0.5
0.5
Formulation Type
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Solid
Batch 21







EPA Reg. No.
228-161
8378-42
8378-43
8378-44
9198-82
9198-84
9198-85
Percent active ingredient
0.7
0.7
0.5
0.6
0.52
0.65
0.71
Formulation Type
Solid
Solid
Solid
Solid
Solid
Solid
Solid
225

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9198-166
10404-29
10404-40
35512-36
62719-316
0.55
0.74
0.42
0.67
0.7
Solid
Solid
Solid
Solid
Solid
Batch 22





EPA Reg. No.
572-329
10088-84
28293-99
62719-89
62719-90
Percent active ingredient
0.5
0.5
0.5
0.4
0.2
Formulation Type
Liquid
Liquid
Liquid
Liquid
Liquid
Batch 23


EPA Reg. No.
10088-94
28293-121
Percent active ingredient
Chlorpyrifos- 0.5 Resmethrin -0.11
Chlorpyrifos - 0.5 Resmethrin -0.11
Formulation Type
Liquid
Liquid
Batch 24



EPA Reg. No.
655-786
11474-66
28293-87
Percent active ingredient
Chlorpyrifos-0.5 PBO-0.26 Pyrethrins- 0.052
Chlorpyrifos - 0.5 PBO- 0.26 Pyrethrins - 0.052
Chlorpyrifos - 0.5 PBO- 0.26 Pyrethrins - 0.052
Formulation Type
Liquid
Liquid
Liquid
Batch 25


EPA Reg. No.
28293-142
28293-149
Percent active ingredient
Chlorpyrifos - 0.5 N-octyl bicycloheptene
dicarboximide -0.4 Allethrin - 0.05
Chlorpyrifos - 0.5 N-octyl bicycloheptene
dicarboximide - 0.4 Allethrin - 0.05
Formulation Type
Liquid
Liquid
Batch 26

EPA Reg. No.
11474-40
Percent active ingredient
Chlorpyrifos-0.5 N-octyl bicycloheptene
dicarboximide - 0.4 Allethrin- 0.054
Formulation Type
Liquid
226

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11474-93
Chlorpyrifos- 0.5 N-octyl bicycloheptene
dicarboximide- 0.4  Allethrin - 0.054
Liquid
Batch 27


EPA Reg. No.
9198-98
9198-99
Percent active ingredient
Chlorpyrifos- 0.57 Benefin - 0.77 Trifluralin - 0.38
Chlorpyrifos- 0.57 Benefin - 0.38 Trifluralin- 0.19
Formulation Type
Liquid
Liquid
No Batch























EPA Reg. No.
499-405
499-413
665-441
1386-613
7501-31
8329-18
8329-20
8329-24
8329-36
9198-168
9198-200
9444-184
9444-202
9688-131
10088-85
11474-55
11474-90
13283-14
13283-17
26693-2
28293-203
28293-204
28293-205
Percent active ingredient
Chlorpyrifos- 8.0 Cyfluthrin - 1.6
Chlorpyrifos- 0.5
Chlorpyrifos- 13.0 Dichlorvos- 4.82
Chlorpyrifos- 6.97
Chlorpyrifos-30.0
Chlorpyrifos- 24.6
Chlorpyrifos- 19.36
Chlorpyrifos- 13.6
Chlorpyrifos- 12.0 Permethrin- 4.0
Chlorpyrifos-0.92
Chlorpyrifos- 0.45 Pendimethalin- 0.68
Chlorpyrifos- 0.5
Chlorpyrifos- 0.50
Chlorpyrifos- 0.50 Sulfluramid- 1.0
Chlorpyrifos- 0.5 PBO-0.1 Pyrethrins-0.05
N-octyl bicycloheptene dicarboximide- 0.166
Chlorpyrifos- 0.5 PBO- 0.260 Pyrethrins - 0.052
Chlorpyrifos -0.5 PBO- 0.260 Pyrethrins - 0.052
Chlorpyrifos- 5.0
Chlorpyrofos-7.0
Chlorpyrifos- 2.0
Chlorpyrifos- 1.0
Chlorpyrifos- 44.4
Chlorpyrifos- 12.6
Formulation Type
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid

Liquid
Solid
Solid
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid
Liquid
Solid
Liquid
Solid
Liquid
Liquid
                                227

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28293-265
34704-65
39039-2
39039-6
45600-1
48273-14
51036-300
55431-1
60061-100
62719-34
62719-47
62719-79
62719-293
62719-295
62719-350
62719-354
66222-4
67517-36
67760-10
67760-14
Chlorpyrifos- 6.7
Chlorpyrifos- 22.4
Chlorpyrifos- 5.0 Cypermethrin-7.0 PBO-3.5
Chlorpyrifos-9.5 Diazinon- 30.0
Chlorpyrifos- 0.86
Chlorpyrifos- 44.9
Chlorpyrifos- 15.0
Chlorpyrifos- 42.4
Chlorpyrifos- 0. 1 3-Iodo-2-Propynyl butyl
Carbamate- 0.5
Chlorpyrifos- 15.0
Chlorpyrifos- 44.9
Chlorpyrifos- 22.9
Chlorpyrifos- 75.0
Chlorpyrifos-30.0
Chlorpyrifos- 22.8
Chlorpyrifos-30.0
Chlorpyrifos-2.3
Chlorpyrifos-9.4 Permethrin- 7.2 PBO- 2.0
Chlorpyrifos- 43. 2
Chlorpyrifos- 15.0
Liquid
Liquid
Solid
Solid
Liquid
Liquid
Solid
Liquid
Liquid
Solid
Liquid
Liquid
Solid
Solid
Liquid
Liquid
Solid
Solid
Liquid
Solid
228

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Appendix H. List of Registrants Sent this Data Call-In
                       229

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230

-------
Appendix I.  List of Available Related Documents and Electronically Available
            Forms
                                 231

-------
Appendix I.  LIST OF AVAILABLE RELATED DOCUMENTS AND
             ELECTRONICALLY AVAILABLE FORMS
Pesticide Registration Forms are available at the following EPA internet site:

             http://www.epa.gov/opprd001/forms/

Pesticide Registration Forms (These forms are in PDF format and require the Acrobat reader)

Instructions

       1.     Print out and complete the forms. (Note: Form numbers that are bolded can be filled
             out on your computer then printed.)

       2.     The completed form(s) should be submitted in hardcopy in accord with the existing
             policy.

       3.     Mail the forms, along with any additional documents necessary to comply with
             EPA regulations covering your request, to the address below for the Document
             Processing Desk.

DO NOT fax or e-mail any form containing 'Confidential Business Information' or 'Sensitive
Information.'

If you have any problems accessing these forms, please contact Nicole Williams at (703) 308-5551
or by e-mail at williams.nicole@epa.gov.

The following Agency Pesticide Registration Forms are currently available via the internet:
at the following locations:
8570-1
8570-4
8570-5
8570-17
8570-25
8570-27
8570-28
Application for Pesticide
Registration/Amendment
Confidential Statement of Formula
Notice of Supplemental Registration of
Distribution of a Registered Pesticide
Product.
Application an Experimental Use Permit
Application for/Notification of State
Registration of a Pesticide To Meet a
Special Local Need
Formulator's Exemption Statement
Certification of Compliance with Data
Gap Procedures
http://www.epa.sov/opprd001/forms/8570-l.pdf

http://www.epa.sov/opprd001/forms/8570-4.pdf
http://www.epa.sov/opprd001/forms/8570-5.pdf

http://www.epa.sov/opprd001/forms/8570-17.pdf

http://www.epa.sov/opprd001/forms/8570-25.pdf

http://www.epa.sov/opprd001/forms/8570-27.pdf
http://www.epa.sov/opprd001/forms/8570-28.pdf

                                         232

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8570-30
8570-32
8570-34
8570-35
8570-36
8570-37
Pesticide Registration Maintenance Fee
Filing.
Certification of Attempt to Enter into an
Agreement with other Registrants for
Development of Data
Certification with Respect to Citations of
Data (PR Notice 98-5)
Data Matrix (PR Notice 98-5)
Summary of the Physical/Chemical
Properties (PR Notice 98-1)
Self-Certification Statement for the
Physical/Chemical Properties (PR No
98-1)
http://www.epa.sov/opprd001/forms/8570-30.pdf

http://www.epa.sov/opprd001/forms/8570-32.pdf

http://www.epa.sov/opppmsdl/PR Notices/pr98-5.pdf

http://www.epa.sov/opppmsdl/PR Notices/pr98-5.pdf

http://www.epa.sov/opppmsdl/PR Notices/pr98-l.pdf

http://www.epa.sov/opppmsdl/PR Notices/pr98-l.pdf

Pesticide Registration Kit

Dear Registrant:
                          www.epa.gov/pesticides/registrationkit/
      For your convenience, we have assembled an online registration kit which contains the
following pertinent forms and information needed to register a pesticide product with the U.S.
Environmental Protection Agency's Office of Pesticide Programs (OPP):

1.     The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and the Federal Food,
      Drug and Cosmetic Act (FFDCA) as Amended by the Food Quality Protection Act (FQPA)
      of 1996.
3.
Pesticide Registration (PR) Notices

a.      83-3 Label Improvement Program—Storage and Disposal Statements
b.      84-1 Clarification of Label Improvement Program
c.      86-5 Standard Format for Data Submitted under FIFRA
d.      87-1 Label Improvement Program for Pesticides Applied through Irrigation
       Systems (Chemigation)
e.      87-6 Inert Ingredients in Pesticide Products Policy Statement
f      90-1 Inert Ingredients in Pesticide Products; Revised Policy Statement
g.      95-2 Notifications, Non-notifications, and Minor Formulation Amendments
h.      98-1 Self Certification of Product Chemistry Data with Attachments (This
       document is in PDF format and requires the Acrobat reader.)

Other PR Notices can be found at http://www.epa.gov/opppmsdl/PR_Notices

Pesticide Product Registration Application Forms (These forms are in PDF format and will
require the Acrobat reader).
                                         233

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       a.     EPA Form No. 8570-1, Application for Pesticide Registration/Amendment
       b.     EPA Form No. 8570-4, Confidential Statement of Formula
       c.     EPA Form No. 8570-27, Formulator's Exemption Statement
       d.     EPA Form No. 8570-34, Certification with Respect to Citations of Data
       e.     EPA Form No. 8570-35, Data Matrix

4.      General Pesticide Information (Some of these forms are in PDF format and will require the
       Acrobat reader).

       a.     Registration Division Personnel Contact List
   B.  Biopesticides and Pollution Prevention Division (BPPD) Contacts
   A.  Antimicrobials Division Organizational Structure/Contact List
       d.     53 F.R. 15952, Pesticide Registration Procedures; Pesticide Data Requirements
             (PDF format)
       e.     40 CFR Part 156, Labeling Requirements for Pesticides and Devices (PDF format)
       f     40 CFR Part 158, Data Requirements for Registration (PDF format)
       g.     50 F.R. 48833, Disclosure of Reviews of Pesticide Data (November 27, 1985)

       Before submitting your application for registration, you may wish to consult some
       additional sources of information.  These include:

1.      The Office of Pesticide Programs' website.

2.      The booklet "General Information  on Applying for Registration of Pesticides in the United
       States", PB92-221811, available through the National Technical Information Service
       (NTIS) at the following address:

                    National Technical  Information Service (NTIS)
                    5285 Port Royal Road
                    Springfield, VA 22161

             The telephone number for NTIS is (703) 605-6000.

3.      The National Pesticide Information Retrieval System (NPIRS) of Purdue University's
       Center for Environmental and Regulatory Information Systems. This service does charge a
       fee for subscriptions and custom searches.  You can contact NPIRS by telephone at (765)
       494-6614 or through their website.

4.      The National Pesticide Information Center (NPIC) can provide information on active
       ingredients, uses, toxicology, and chemistry of pesticides.  You can contact NPIC by
       telephone at 1-800- 858-7378 or through their website: http://npic.orst.edu.

       The Agency will return a notice of receipt of an application for registration or amended
       registration, experimental use permit, or amendment to a petition if the applicant or
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       petitioner encloses with his submission a stamped, self-addressed postcard. The postcard
       must contain the following entries to be completed by OPP:

                    1.     Date of receipt;
                    2.     EPA identifying number; and
                    3.     Product Manager assignment.

       Other identifying information may be included by the applicant to link the
       acknowledgment of receipt to the specific application submitted.  EPA will stamp the date
       of receipt and provide the EPA identifying file symbol or petition number for the new
       submission. The identifying number should be used whenever you contact the Agency
       concerning an application for registration, experimental use permit, or tolerance petition.

       To assist us in ensuring that all data you have submitted for the chemical are properly
       coded and assigned to your company, please include a list of all synonyms, common and
       trade names, company experimental codes, and other names which identify the chemical
       (including "blind" codes used when a sample was submitted for testing by commercial or
       academic facilities). Please provide a chemical abstract system (CAS) number if one has
       been assigned.

Documents Associated with this RED

       The following documents are part of the Administrative Record for this RED document
and may be 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 respective Chemical Status Sheet.

       1.     Health Effects Division and Environmental Fate and Effects Division Science
             Chapters, which include the complete risk assessments and supporting documents.
       2.     Detailed Label Usage Information System (LUIS) Report.
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