Docket Number: EPA-HQ-OPP-2010-0119 www.regulations.gov

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# Chlorpyrifos-methyl Summary Document Registration Review: Initial Docket

March 20103 

### TABLE OF CONTENTS

I. PRELIMINARY WORK PLAN................................................................................. 4

II. FACT SHEET ............................................................................................................. 9



### Please Note

This Preliminary Work Plan and Fact Sheet su mmarize the Environmental Protection Agency’s current position based on the following documents:

1. Chlorpyrifos-methyl. Human Health A ssessment Scoping Document in Support of Registration Review. January 12, 2010.

2. Registration Review Problem Formul ation for Chlorpyrifos-methyl. November 23,

2009.

3. Usage/Label Use Report for Chlorpyrifos-methyl. April 24, 2009.

4. Updated Review of Chlorpyrifo s Methyl Incident Reports. November 24, 2009.

These and other supporting documents for the chlo rpyrifos-methyl registration review case may be found in the docket EPA-HQ-OPP- 2010-0119 at http://www.regulations.gov.4 I. PRELIMINARY WORK PLAN

Introduction

The Food Quality Protection Act (FQPA) of 1996 mandated a re gistration review program. All pesticides distributed or sold in the United States generally must be registered by the U.S. Environmental Protection Agency (EPA or the Agency), based on scientific data showing that they will not cause unreasonable ri sks to human health or the environment when used as directed on product labeling. The regist ration review program is intended to make sure that, as the ability to assess risk evolves and as policies and practices change, all registered pesticides continue to meet th e statutory standard of no unreas onable adverse effects to human health or the environment. Changes in science, public policy, and pesticide use practices will occur over time. Through the registration review program, the Agency pe riodically reevaluates pesticides to make sure that as change occurs, products in the marketplace can be used safely. Information on this program is provided at www.epa.gov/oppsrrd1/registration_review/

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The Agency is implementing the registration re view program pursuant to Section 3(g) of the Federal Insecticide, Fungicide, and Rode nticide Act (FIFRA), and will review each registered pesticide every 15 years to determine wh ether it continues to m eet the FIFRA standard for registration. The Agency will consider bene fits information and data as required by FIFRA. The public phase of registration review begins wh en the initial docket is opened for each case. The docket is the Agency’s opportunity to stat e what it knows about the pesticide and what additional risk analyses and data it believes are needed to make a registration review decision. After reviewing and responding to comments and data received in the docket during this initial comment period, the Agency will develop and commit to a final work plan and schedule for the registration review of chlorpyrifos-methyl.

Chlorpyrifos-methyl (case # 8011) is an orga nophosphate (OP) insecticide registered for use to control a variety of insect s including beetles, weev ils, moths, and grain borers. Like other OP insecticides, chlorpyrifos-methyl acts th rough inhibition of acetylcholinesterase. Chlorpyrifos-methyl was first registered in 1985 for use on stored grain, such as wheat, barley, oats, rice, and sorghum. There are two chlor pyrifos-methyl products currently registered: a technical-grade product, and an e nd-use product. Chlorpyrifos-methyl is only registered for use as an indoor treatment for small grains in storage bins and warehouses. A Tolerance Reassessment and Risk Management Eligibility Decision document (TRED) was issued for chlorpyrifos-methyl in January 2001; the TRED was finalized with the OP cumulative in 2006.

Chlorpyrifos-methyl is closely related to ch lorpyrifos (case # 0100), a general use OP insecticide registered for use for control of folia ge and soil-borne insect pests on a variety of food and feed crops. The chlorpyrifos preliminar y and final work plans in correctly stated that chlorpyrifos-methyl shares the same case number as chlorpyrifos. While the two chemicals are closely related, the chlorpyrifos-m ethyl case is being handled separa tely (the chlorpyrifos-methyl case number is 8011). The chlorpyrifos final work plan is available at http://www.regulations.gov.5 Anticipated Risk Assessment and Data Needs:

The Agency anticipates that no quantitative ecological risk assessment, quantitative endangered species assessment, or drinking water assessment will be needed for chlorpyrifosmethyl because all registered uses are indoor uses only. Chlorpyrifos-methyl is applied by manual and automatic sprayer in self-contained units with little potential for offsite transport. The application method does not a llow for drift to terr estrial areas or to water bodies. The application is not intended for moist areas and does not contain amounts of active ingredient sufficient for runoff to be a concern. In addition, the use pattern is unlikel y to result in exposure to aquatic resources or groundwater and thus drinking water is un likely to be impacted by this

use.

The Agency anticipates conducting human heal th risk assessments for chlorpyrifosmethyl. Below is a summary of the issues releva nt to the registration re view of chlorpyrifosmethyl.

Human Health Risk:

• A comprehensive human health risk assessm ent was conducted in April 2000 to support the 2001 Tolerance Reassessment and Risk Management Decision (TRED).

• The TRED did not include a residential or dr inking water risk assessment. There are no registered uses of chlorpyrifos -methyl that result in reside ntial exposure or exposure from drinking water. Exposure to chlorpyrifos -methyl may occur via food, and occupational activities may result in dermal and inhalation exposures.

• During the reregistration of chlorpyrifos, the Agency determined that the metabolite TCP, common to both chlorpyrifos and chlorpyfios-me thyl, is no longer considered to be of toxicological concern, and recommended th e removal of TCP from the tolerance expression of chlorpyrifos-methyl. Tolera nces for resides in/on plant and animal commodities should be changed to be expresse d in terms of parent chlorpyrifos-methyl only (40 CFR 180.419).

• During registration review, the chlorpyrif os-methyl tolerance expression (40 CFR 180.419) will be reviewed to ensure that it appropriately covers the metabolites and degradates of chlorpyrifos-methyl and that it specifies the residues to be measured for each commodity.

• Because of the use pattern for chlorpyrifos-m ethyl (on stored grains and inside grain storage facilities), residues in water are not anticipated. Theref ore, a drinking water exposure analysis was not conducted and will no t be required under registration review. If acute and chronic points of departure ar e revised, the Agency will conduct a food-only dietary assessment unde r registration review.

• The Agency anticipates updated occupational handler and occupational post-application

risk assessments will be needed for chlor pyrifos-methyl. The concentration of active ingredient has changed in the single re maining chlorpyrifos-methyl end-use product.

• The database is complete with the exception of the following studies, which the Agency anticipates requiring in order to conduc t a complete human health assessment:6 ○ 870 Series acute toxicity studies (acute oral, acute dermal, acute inhalation, primary eye irritation, prim ary skin irritation). The dermal sensitization study will not be required.

○ 870.3250 Subchronic inhalation study

○ 870.7800 Immunotoxicity (rats)

○ Non-guideline study: Comparative cho linesterase assay (CCA): required for organophosphates including chlorpyrifos-methyl.

○ 860.1500 Magnitude of the residue data we re identified as outstanding in the 2000 TRED for aspirated grain fractio ns. Those data will be required in registration review.

• The recent cumulative risk assessmen t for the organophosphates includes a comprehensive assessment of OP exposure a nd no risks of concer n were identified for chlorpyrifos-methyl. Should the Agency determ ine that new information on chlorpyrifosmethyl is available which could potentially impact the cumulative risk assessment and result in a risk of concern, the Agency will revisit the cumulative risk assessment.

• Please refer to Chlorpyrifos Methyl. Human Health Assessment Scoping Document in Support of Registration Review, dated January 12, 2010, locatedin the chlorpyrifosmethyl docket, for a detailed discussion of th e anticipated human health risk assessment

needs.

Other Data Needs:

• OPPTS GLN 830.7050 UV/Visible Light Absorption – this study is a new data requirement under 40 CFR part 158 (Produc t Chemistry Data Requirements) for registration of a pes ticide (food and non-food uses). The Agency anticipates requiring this study to obtain basic information about the compound’s identity/composition and the wavelengths at which the compound may be susceptible to photoc hemical degradation.

Endocrine Disruptor Screening Program (EDSP): As required under FFDCA section 408(p), EP A has developed the Endocrine Disruptor Screening Program (EDSP) to determine whether certain substances (inc luding pesticide active and other ingredients) may have an effect in humans or wildlife si milar to an effect produced by a “naturally occurring estrogen, or other such endocrine effects as the Administrator may designate.” The EDSP employs a two-tiered ap proach to making the statutorily required

determinations. Tier 1 consists of a battery of 11 scr eening assays to identify the potential of a chemical substance to interact with the estrog en, androgen, or thyroid (E, A, or T) hormonal systems. Chemicals that go th rough Tier 1 screening and are found to have the potential to interact with E, A, or T hormonal systems will proceed to the next stag e of the EDSP where EPA will determine which, if any, of th e Tier 2 tests are necessary base d on the available data. Tier 2 testing is designed to identify a ny adverse endocrine related eff ects caused by the substance, and establish a quantitative relationship betw een the dose and the E, A, or T effect.7 Between October 2009 and February 2010, EPA issued test orders/data call-ins for the first group of 67 chemicals, which contains 58 pest icide active ingredient s (ais) and 9 inert ingredients. This list of chemicals was sele cted based on the potenti al for human exposure through pathways such as food and water, resi dential activity, and cer tain post-application agricultural scenarios. This list should not be construed as a list of known or likely endocrine disruptors.

Chlorpyrifos-methyl is not among the group of 58 pe sticide ais on the initial list to be screened under the EDSP. Under FFDCA sec. 408(p) the Agen cy must screen all pesticide chemicals. Accordingly, EPA anticipates issuing future EDSP orders/data call-ins for all registration review cases, including those for which EPA has alr eady opened a registration review docket for a pesticide ai.

For further information on the status of the ED SP, the policies and procedures, the list of 67 chemicals, the test guidelines and the Tier 1 screening battery, pleas e visit our website: http://www.epa.gov/endo/.

Timeline: EPA has created the following estimated timeline for the completion of th e chlorpyrifos-methyl registration review.

Registration Review for Chlo rpyrifos-Methyl – Projected Re gistration Review Timeline

Activities Estimated Date Opening the docket Open Docket and Public Comment Period 2010 – Mar. Close Public Comment 2010 – May Case Development Final Work Plan 2010 – Aug. Issue DCI 2011 – Apr.- June Data Submission 2013 – Apr. - June Open Public Comment Period for Preliminary Risk Assessments 2014 – Oct. - Dec.

Close Public Comment Period 2015 – Jan. – Mar. Registration Review Decision Open Public Comment Period for Proposed Registration Review

Decision 2015 – Apr. – June.

Close Public Comment Period 2015 – July – Sept. Final Registration Review Decision a nd Begin Post-Decision Follow-up 2016 Total (years) 6

Guidance for Commenters: The public is invited to comme nt on EPA’s preliminary regist ration review work plan and rationale. The Agency will carefully consid er all comments as well as any additional information or data provided in a timely manne r prior to issuing a fi nal work plan for the chlorpyrifos-methyl case.8 Trade Irritants

• Through the registration review process, th e Agency intends to solicit information on trade irritants and, to the extent feasible, take steps toward fa cilitating irritant resolution.

Growers and other stakeholders are asked to comment on any trade irritant issues resulting from lack of Maximum Residue Le vels (MRLs) or disparities between U.S. tolerances and MRLs in key export markets, providing as much specificity as possible regarding the nature of the concern.

Water Quality

• Chlorpyrifos-methyl is not iden tified as a cause of impairme nt for any water bodies listed as impaired under section 303(d) of the Clean Water Act, based on information provided

at http://iaspub.epa.gov/tmdl_waters10/attain s_nation_cy.cause_detail_303d?p_cause_grou p_id=885 . In addition, no Total Maximum Daily Loads (TMDL) have been developed for [insert pesticide], based on information provided at http://iaspub.epa.gov/tmdl_waters10/attain s_nation.tmdl_pollutant _detail?p_pollutant_gr oup_id=885&p_pollutant_group_name=PESTICIDES . More information on impaired

water bodies and TMDLs can be found at http://www.epa.gov/owow/tmdl/ . The Agency invites submission of water quality data for this pesticide. To the extent possible, data should conform to the quality standards in Appendix A of the OPP Standard Operating Procedure: Inclusion of Im paired Water Body and Other Water Quality Data in OPP’s Registration Review Risk A ssessment and Management Process (see: http://www.epa.gov/oppsrrd1/regist ration_review/water_quality_sop.htm ) in order to ensure they can be used quantitatively or qualitatively in pesticide risk assessments.

Environmental Justice

• EPA seeks to achieve environmental justi ce, the fair treatment and meaningful involvement of all people, regardless of race, color, national origin, or income, in the development, implementation, and enforcemen t of environmental laws, regulations, and policies. To help address potential environmental justice issues, the Agency seeks information on any groups or segments of the population who, as a result of their location, cultural practices, or other factor s, may have atypical, unusually high exposure to chlorpyrifos-methyl, compared to the ge neral population. Pleas e comment if you are aware of any sub-populations that may ha ve atypical or unusually high exposure compared to the general population.

Additional Information Stakeholders are also asked to provide informa tion and data that will assist the Agency in refining risk assessments.

Next Steps: After the 60-day public comment period closes , the Agency will review and respond to any comments received in a timely manner and then issu e a Final Work Plan for chlorpyrifos-methyl.9 II. FACT SHEET

Background Information :

• Chlorpyrifos-methyl Registration Review Case Number: 8011

• Chlorpyrifos-methyl PC Code: 059102; CAS#: 5598-13-0

• Technical Registrant: Dow AgroSciences LLC

• Chlorpyrifos-methyl was first registered in 1985.

• A Tolerance Reassessment and Risk Manageme nt Eligibility Decisi on document (TRED) for chlorpyrifos-methyl was completed in January 2001 and was finalized with the OP

cumulative in 2006.

• Tolerances for chlorpyrifos-methyl range from 0.5 ppm to 130 ppm [40 CFR 180.419]

• Pesticide Re-evaluation Di vision (PRD) Chemical Revi ew Manager (CRM) Katie Weyrauch ( weyrauch.katie@epa.gov )

• Registration Division (RD) C ontact: Marianne Lewis ( lewis.marianne@epa.gov )

Use & Usage Information:

• Chlorpyrifos-methyl is an organophosphate (OP) insecticide registered for use to control a variety of insects including beetles, weev ils, moths, and grain borers. Chlorpyrifosmethyl is registered for use on stored gr ain, such as wheat, ba rley, oats, rice, and sorghum. Chlorpyrifos-methyl is registered fo r use only used as an indoor treatment for small grains in storage bins and warehouses

• According to data from the United States Department of Agriculture’s National Agricultural Statistics Service and private market research, approximately 110,000 lbs a.i. are used annually.

Recent Actions

• At the conclusion of the TRED, the chlorpyr ifos-methyl registrants requested voluntary cancellation of all registrations. A Federa l Register Notice announc ing the receipt of request for registration cancellation was published on April 24, 2002 (FR 67 20118) (FRL-6773-1).

• The Agency received public comments on the request for voluntar y cancellation that compelled it to change the terms of the cancellation. A Federal Register Notice was published on July 7, 2004 (FR 69 40906) (FRL-7363-9) amending the TRED and the request for registration cancellation. This FRN extended the phase-out dates for the remaining end-use chlorpyrifos-methyl pr oducts and maintained the only remaining technical product registration (product number 62719-42). EPA requested comment on the July 7, 2004 FRN action.

• On December 5, 2007 (FR 72 68580) (FRL-8155- 5), EPA issued a product cancellation order further extending the phase-out dates fo r the remaining end-use products based on comments received on the July 7, 2004 FRN. The Agency granted an extension of the existing registrations until an equally eff ective stored grain product was registered. Storicide II, a chlorpyrifos-methyl / deltame thrin product was conditi onally registered on10 October 27, 2004 (EPA Reg. No. 264-992). Storic ide II contains half the concentration of chlorpyrifos-methyl compared to earlier chlorpyrifos-methyl end-use products.

• There are two currently regi stered chlorpyrifos-methyl products: a technical-grade product, Reldan F Insecticidal Chemical (Reg. No. 62710-42), and an end-use product, Storicide II Grain, Bin, and Warehouse Insecticide (Reg. No. 264-992).

Ecological Risk Assessment Status : Please refer to the Registration Review Problem Formulation for Chlorpyrifos-methyl, dated November 23, 2009, and located in the chlorpyrifos-methyl docket at regulations.gov (EPA-HQOPP-2010-0119).

• An ecological risk assessment was completed in 1980 for chlorpyrifos-methyl prior to its registration in 1985.

• No ecological risk has been identified for ch lorpyrifos-methyl because all uses are indoor

uses that do not lead to ecol ogical exposure. According to product toxicity data, all enduse products are toxic to extremely toxic to fi sh, birds, and other wildlife. Data from early risk assessments indicate that chlor pyrifos-methyl is pract ically nontoxic to moderately toxic to avian wildlife based on dosing studies; pract ically nontoxic to slightly toxic to avian wildlife based on diet ary studies; moderately toxic to very highly

toxic to fish based on acute da ta; slightly to very highly toxic to aquatic invertebrates based on acute tests; and very highly t oxic to honeybees based on acute studies.

• No acceptable fate data have been submitted to EPA for chlorpyrifos-methyl. Previous data summaries were prepared based on overvie ws of the environmental fate as captured in open literature.

• All registered chlorpyrifos-methyl uses are i ndoor uses. Chlorpyrifos-methyl is applied by manual and automatic sprayer in self-contained units with little potential for offsite transport. The application method does not allo w for drift to terrestrial areas or to water bodies. The application is not intended for moist areas and does not contain amounts of active ingredient sufficient for runoff to be a concern. In additi on, the use pattern is unlikely to result in exposure to aquatic re sources or groundwater a nd thus drinking water is unlikely to be impacted by this use.

Human Health Risk Assessment Status:

Please refer to Chlorpyrifos-methyl. Human Health A ssessment Scoping Document in Support of Registration Review, dated January 12, 2010, and located in the chlorpyrifos-methyl docket at regulations.gov (EPA-HQ-OPP-2010- 0119), for a discussion of the key findings of the most

recent human health risk assessment for chlorpyrifos-methyl. A summary follows:

Hazard Characterization:

• In the 2001 TRED, the short-term dermal a nd inhalation endpoint selected was a no

observed adverse effect le vel (NOAEL) of 1.0 mg/kg/da y based on cholinesterase inhibition from a developmental toxicity study in rats. The intermediate-term dermal and inhalation endpoint selected was a NOAEL of 0.1 mg/kg/day based on cholinesterase

inhibition from a chronic/carci nogenicity study in rats.11 Dietary (Food Only):

• The most recent dietary exposure assessment was conducted in association with the 2001 TRED. Dietary risk estimates for chlor pyrifos-methyl were below EPA’s level of concern for the general populati on and all population subgroups.

• Because chlorpyrifos-methyl is only used on stor ed grains inside grain storage facilities, residues in drinking water are not anticipat ed. Therefore a drinking water exposure analysis was not conducted.

Residential:

• The 2001 TRED did not assess residential s cenarios because there are no registered residential uses of chlorpyrifos-methyl.

Aggregate:

• There are no residential uses of chlorpyrifos-methy l; therefore, aggregate risk estimates are equivalent to the dietary es timates and are not of concern.

Occupational :

• The 2000 occupational assessment was based on the chlorpyrifos-methyl product Reldan 4E (43% emulsifiable concentr ate) and dust products. Handler estimates were of concern for all but one scenario – mixing and loading liquids for direct grain treatment using an automated system.

• In response to those concerns, the registrant requested voluntary cancellation of all dust products and agreed to mitigation measures to address risks to handlers of the liquid

formulation.

• Post-application risks from liquid applica tions were expected to be minimal.

• Dust formulations were cancelled in 2002, and Reldan 4E (43% emulsifiable concentrate (EC)) was cancelled in 2007. The only curren tly registered formulation is a 22% EC (Storicide II). The 22% may be applied to stored grains at 3 pp m, whereas the 43% EC was applied at 6 ppm.

• Updated occupational handler and post-app lication exposure assessment are necessary.

• Past chlorpyrifos-methyl risk assessments rely in part on data from studies in which adult human subjects were intentionally exposed to a pesticide to determine their dermal and inhalation exposure. Many such studies, invo lving exposure to many different pesticides, comprise generic pesticide exposure database s such as the Pestic ide Handlers Exposure Database (PHED) and the Agricultural Reen try Task Force (ARTF) Database. EPA has reviewed all the studies in these multi-pes ticide generic exposure databases, and on the

basis of available evidence ha s found them to have been ne ither fundamentally unethical nor significantly deficient re lative to standards of ethi cal research conduct prevailing when they were conducted. There is no regul atory barrier to con tinued reliance on these studies, and all applicable requirements of EPA’s Rule for the Protection of Human Subjects of Research (40 CFR Pa rt 26) have been satisfied.

Cumulative:12 • Chlorpyrifos-methyl use was assessed as part of the organophosphate cumulative risk assessment, completed in July 2006. No cu mulative risks of concern for chlorpyrifosmethyl were identified in that assessment.

Incidents:

Ecological:

• Since chlorpyrifos-methyl is registered for indoor use only, EPA did not search the Ecological Incident Information System (EIIS ) for ecological incidents associated with chlorpyrifos-methyl.

Human:

• The OPP Incident Database System (IDS) wa s searched for human incidents involving chlorpyrifos-methyl in the United States from 2002 to the present. IDS includes reports of incidents from various sources, including mandatory FIFRA Section 6 (a) (2) reports from registrants, other federal and state hea lth and environmental agencies and individual

consumers. This review indicate s that no incidents were reported.

Data Call-In Status:

• No chemical-specific data call-ins (DCIs) have been issued for chlorpyrifos-methyl since

the 2001 TRED. DCIs were issued for chlo rpyrifos-methyl in 1992 for product chemistry data, 1995 for agricultural handler data, and 1999 for developmental neurotoxicity data. All requirements have been satisfied with ei ther a waiver request, bridging of data, or

data submission.

• After the 2001 chlorpyrifos-m ethyl TRED was issued, EPA allowed for several of the data gaps identified in the TRED to be sati sfied with studies from chlorpyrifos, a closely related organophosphate insectic ide. The studies expected to be required in this registration review are listed in the Prelimin ary Work Plan under the “Anticipated Risk Assessment and Data Needs” section (p. 4).

Tolerances and International Harmonization:

• Maximum Residue limits (MRLs) for chlorpyr ifos-methyl have been established by the Codex Alimentarius Commission. However, the majority of these MRLs are not harmonized with U.S. tolerances. Any chlo rpyrifos-methyl tolera nces reassessed during registration review will be considered for possible harmonization with international

MRLs. Canadian and Mexican MRLs have not been established.

• Chlorpyrifos-methyl tolerances in 40 CF R 180.419 are currently expressed as the combined residues of chlorpyrifos-methyl a nd TCP (2,5,6-trichloro-2- pyridinol) in or on plant commodities. EPA previously concluded that the U.S. tolerance expression should be amended to include only chorpyrifos-methyl. Accordingly, the tolerance definition for chlorpyrifos-methyl should be amended to include only chlorpyrifos-methyl.

• During registration review, the chlorpyrif os-methyl tolerance expression (40 CFR 180.419) will be reviewed to ensure that it appropriately covers the metabolites and degradates of chlorpyrifos-methyl and that it specifies the residues to be measured for each commodity.13 Labels : Labels can be obtained from the Pesticid e Product Label System (PPLS) website: http://oaspub.epa.gov/pestlabl/ppls.home

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