Memorandum Supporting Decision toApprove Registration for the Uses ofDicamba on Dicamba Tolerant Cotton andSoybeanDigitally signed byMARIETTAMARIETTA ECHEVERRIADate: 2020.10.27 11:38:52ECHEVERRIA-04'00'Approved by:Marietta Echeverria, Acting DirectorRegistration DivisionOffice of Pesticide ProgramsOctober 27, 2020

Table of ContentsContentsI. Summary. 3II. Chemical Information . 5III. Background . 6IV. 2020 Registration Actions . 9V. Stakeholder Feedback . 10VI. Risk Assessments. 11A. Human Health. 11B. Ecological . 11VII. Benefits and Impacts Assessments . 15A.Benefits of the Registration of Dicamba Use in DT Cotton and DT Soybeans . 15B.Impacts Assessment . 17VIII. Registration Decision . 18B.Label Requirements. 22C.Terms of Registration. 24D.Registration Expiration . 26E.Geographic Limitation of the Registration . 26IX. EPA’s Effects Determinations under the ESA . 262

I. SummaryThis memorandum presents the rationale to support the decisions of the U.S. EnvironmentalProtection Agency (referred hereafter as EPA or the Agency) to register 1 under section 3(c)(5) ofthe Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), three end use dicamba productsfor use on dicamba tolerant (DT) cotton and soybeans. Bayer and BASF submitted registrationapplications on July 2, 2020 for new registrations of XtendiMax and Engenia for use on DTcotton and DT soybeans. Syngenta submitted an application for a label amendment on August 12,2020 that proposed extending the upcoming December 20, 2020 expiration date for Tavium.2 Thisdocument does not approve any particular product for sale and distribution. Products areindividually approved through a separate Registration Notice that is the license that permits thesale and distribution of the pesticide product.EPA has evaluated extensive information and data from registrants, academics, weed scientistsand field experts, information from the open literature and even though EPA did not hold apublic comment opportunity for these registration actions, the Agency received and consideredinformation from other stakeholders. EPA conducted robust evaluations of the risks to humanhealth and the environment, including risks to non-target plants from potential spray drift andvolatile emissions, as well as the benefits and impacts to users of the products and non-users.EPA conducted species-specific evaluations to make effect determinations for federally listedendangered and threatened species (listed species), and where necessary consulted with the Fishand Wildlife Service 3 under section 7(a)(2) of the Endangered Species Act (ESA). A recentdecision of 9th Circuit Court of Appeals noted certain deficiencies in EPA's 2018 registrationdecision for certain dicamba products for use on DT crops. While conducting its evaluations forthis new dicamba decision, EPA considered the issues raised by the Court. As explained below,EPA believes this decision meets the FIFRA standard for registration and is supported bysubstantial evidence.Based on these robust assessments, which took into account the control measures required by thelabeling, EPA determined that the applications meet the standard for registration under FIFRAsection 3(c)(5). The labeling requirements and restrictions associated with these registrationactions include a suite of mandatory control measures that address the potential for spray drift,volatile emissions and runoff. These include a national application cut-off date of June 30 andJuly 30 for soybeans and cotton, respectively, the mandatory use of approved volatility reductionadjuvants 4 (VRAs), and a larger infield downwind buffer. Additionally, the registrations restrictuse to certified applicators (and not by persons under their supervision) and require dicambaspecific training on the risks associated with dicamba, required control measures, and resistancemanagement measures necessary to prevent unreasonable adverse effects. The registration alsoincludes requirements for enhanced incident and resistance reporting by the registrants to ensure1One of the products described in this rationale (EPA Registration Number 100-1623; A21472 Plus VaporGripTechnology (Alternate Brand Name: Tavium)) is still registered, but the registration is set to expire in December2020. In the case of that product, EPA has presented the rationale for the decision to extend the registration.2Since Tavium is currently registered for use on DT cotton and DT soybeans, none of these registrations areconsidered to include any new uses.3There were no listed species within the jurisdiction of the National Marine Fisheries Service that requiredconsultation for this action.4Also called volatility reduction agents (VRA) or pH buffering adjuvants.3

EPA has appropriate information to continue monitoring these registrations. EPA is alsorequiring enhanced record-keeping from applicators to ensure compliance with control measures.EPA is requiring as a term of registration the assurances from the registrants that the VRAs/pHBuffering Adjuvants is available in amounts necessary for use with the dicamba products for useon DT crops.The control measures included in these registrations are quite different from those that wereapproved in the actions taken in 2018. Table 1 summarizes the major 2020 control measurescompared to those in the 2018 registrations.Table 1. Summary of major 2020 control measures compared to 2018ElementSpray drift2018 Decision110 ft downwind in-fieldbuffer-Limit of two OTTapplications of dicamba perfield per year for both DTcotton and DT soybeans-Applications only permittedbetween one hour aftersunrise and two hours beforesunset-Use allowed until specifiedcrop growth stage2020 Decision240 ft downwind in-fieldbuffer-Limit of two OTTapplications of dicamba perfield per year for both DTcotton and DT soybeans-Applications only permittedbetween one hour after sunriseand two hours before sunset-Calendar cutoff dates forapplications (June 30th forsoybeans and July 30th forcotton)Volatility – maintaining tankpHAdvisory languageESA – spray driftESA – volatility110 ft downwind buffer57 ft omni-directional bufferin areas with federally listedspeciesLabel clarityIncluded uses for both nonDT crops beyond the cottonand soybean DT cropsRequire use of a qualifiedVRA/pH buffering adjuvant inthe tank for every application310 ft downwind buffer57 ft omni-directional bufferin areas with federally listedspecies, in combination withthe generally applicable cutoff date and VRA/pHbuffering adjuvant in countieswith federally listed species-Only includes pre- andpostemergent uses for cottonand soybean DT cropsCleaner label structure andrestrictions for increasedusability-Simplified early seasonrestriction (crop growth stageVolatility – timing ofapplications4

cut-off vs. calendar cut-offdate)Hooded sprayer option forpartial relief of certain controlmeasuresSpray Tank ContaminationExpiration DateTerms of the registrationsTraining requirementsCompliance assuranceN/AWhen using a qualifiedhooded-sprayer the spray-driftbuffer is reduced to 110 ft and240 ft for FIFRA and ESA,respectively (for use insoybeans only)Equipment clean-outEquipment clean-outrequirementsrequirements2 years5 years-Testing and approval of tank -Testing and approval of tankmixesmixes-Herbicide resistance-Revised herbicide resistancemanagement planmanagement plan-Enhanced reporting of-Revised enhanced reportingadverse effects informationof adverse effects information-Studies to address-Assuring availability ofuncertaintiesapproved VRA/pH bufferingadjuvant-Testing alternate hoodedsprayer equipmentTraining required per labeling Training required, withaddition of new requirementsto include specific informationon 2020 control measures intraining materials.- Recordkeeping requirements - Additional recordkeeping- Restricted userequirements related to thenew control measures- Restricted useII. Chemical InformationThis memorandum supports three 5 dicamba registrations for use on DT soybean and DT cotton(EPA Registration Numbers 264-1210, 100-1623, and 7969-472), as described below.Registrants: BASF; Bayer CropScience (formerly Monsanto Company); and Syngenta CropProtectionProduct Numbers:5Two of the three registrants (Bayer and BASF) that owned products impacted by the 2020 vacatur have submittednew product applications to the Agency. This memorandum addresses those two product applications, as well as theamendment Syngenta submitted to extend the expiration date for the non-vacated product, Tavium.5

1. EPA Reg. #100-1623: A21472 Plus VaporGrip Technology (Alternate Brand Name(ABN) Tavium Plus VaporGrip Technology) (referred hereafter as Tavium)2. EPA Reg. #264-1210: XtendiMax with VaporGrip Technology (referred hereafter asXtendiMax)3. EPA Reg. #7969-472: Engenia Herbicide (referred hereafter as Engenia)Chemical Names:The three pesticide products covered by this memorandum contain two forms of dicamba, as seenin Table 2 below:Table 2. Chemical Name Identification for DicambaChemical NameAlternate ChemicalCommon Name Chemical AbstractNameService (CAS)NumberDicamba (benzoic acid,Diglycolamine salt of Dicamba DGA104040-79-1salt3,6-dichloro-2-methoxy-, dicamba (3,6aka 3,6-dichloro-o-anisic dichloro-o-anisic acid)acid)NoneDicamba1286239-22-2Dicamba: N,N-Bis-(3BAPMA saltaminopropyl)methylamine salt of 3,6dichloro-o-anisic acidMode of Action: Dicamba is in the Benzoic Acid family that is used for selective control ofemerged broadleaf weeds. Like the phenoxy herbicides, dicamba mimics auxins, a type of planthormone and causes abnormal cell growth by affecting cell division.Summary of Product Information:The information from this chemical information section is summarized in Table 2 below:Table 3. Master Table of Dicamba Products Registered for Use on DT Cotton and DT SoybeansEPA Reg. # Product NameRegistrant Form of Dicamba100-1623A21472 Plus VaporGripSyngentaDGA saltTechnology (ABN Tavium)264-1210XtendiMax with VaporGripBayerDGA saltTechnology7969-472Engenia HerbicideBASFBAPMA saltIII. BackgroundIn January 2015, under the Plant Protection Act, the United States Department of Agriculture(USDA) deregulated the genetically modified DT cotton and DT soybean seeds. This seed wassold commercially in late 2015 and 2016 prior to EPA registering a pesticide product for use on6

these DT crops. In late 2016, following a public comment period, 6 EPA registered three dicambaproducts for use with the DT trait in soybean and cotton 7. These registrations were time-limitedwith automatic expiration dates in late 2018, unless EPA granted an extension of this timelimitation.Prior to the 2016 registration actions for dicamba, dicamba uses on soybeans and cotton werelimited to use on preplant and preharvest soybeans and on preplant and postharvest cotton. Thenew uses registered in 2016 under FIFRA section 3(c)(7)(B) expanded the timing of dicambaapplications by allowing a new use for postemergence over-the-top (OTT) applications to DTcotton and DT soybean crops. Registrations for the OTT uses were granted for the lower volatilityproducts when compared to other registered dicamba products for non-OTT uses. Any use of theearlier registered products on DT cotton or DT soybean crops that are not registered specificallyfor postemergent use on DT cotton or DT soybean crops is inconsistent with the pesticide’slabeling and a violation of the FIFRA.Reports of IncidentsIn 2016, EPA began receiving reports of crop injury alleged to be caused by off-target movementfrom the use of dicamba. Because the registrations for OTT use had not yet been issued, EPAconcluded these 2016 incidents were related to misuse of previously registered, more volatiledicamba pesticide products on DT cotton and DT soybeans. In 2017, over 2,700 official cases ofcrop damage were reported to state departments of agriculture, estimated to be over 3.6 millionacres of soybeans 8 (nearly 4% of a total 90.2 million acres planted in 2017 according to USDA).There was a lack of scientific consensus regarding the exact cause of these dicamba reportedincidents. Input from state agencies, farm bureaus, associations, industry, farmers, and nongovernmental organizations indicated that causes could have included not following the label oruse of an older, more volatile formulation inconsistent with those products’ labeling and thus inviolation of FIFRA, physical drift, tank contamination, and/or volatility. In response, EPAworked with the pesticide registrants to strengthen the pesticide label directions for use for the2018 season to further minimize the potential for off-target movement. The restrictions for allOTT registrations of dicamba were amended in 2017 to include labeling restrictions to minimizethe potential for off-site movement of dicamba. The original expiration set for the end of 2018remained a term of the registrations.6Beyond the requirement of FIFRA 3(c)(4) to publish a notice of receipt for certain applications and acceptcomments on the limited information in such notice, FIFRA does not require EPA to provide a public commentopportunity for a proposed decision to register a pesticide. EPA, nevertheless, provided more robust information forpublic comment on its proposed 2016 dicamba decision under its public participation policy blic-participation-process-registration-actions). Similar to the 2018registration actions where EPA did not provide a formal public comment period, again in 2020 EPA did not providea formal public comment opportunity, but the Agency did receive over 120 unsolicited comments from stakeholders.EPA considered the content of these submissions.7EPA Registration Number 524-617 (M1768 Herbicide/XtendiMax With Vaporgrip Technology) was the firstregistration issued in 2016 as described in Final Registration of Dicamba on Dicamba-Tolerant Cotton and Soybean(available on, Docket ID: EPA-HQ-OPP-2016-0187); two additional OTT dicamba use registrationswere approved later in 2016 (EPA Registration Numbers 352-913 (DuPont Fexapan Herbicide) and 7969-345(Engenia Herbicide)).8Dr. Kevin Bradley Univ. of Missouri,IPM, report dicamba injured soybean/7

Information for the 2018 growing season provided by state agencies and others also includedreports of crop injury alleged to be related to off-site movement of dicamba. The registrantssubmitted adverse effects aggregated reports to EPA as required by FIFRA section 6(a)(2). TheAssociation of American Pesticide Control Officials (AAPCO) reported that approximately1,400 official complaints of alleged dicamba injury were reported to the state regulatoryauthorities. Damage alleged to be related to OTT dicamba applications was reported not only fornon-tolerant soybeans but also for neighboring trees, orchards, vineyards, berries, melons,tomatoes and other vegetable crops. As to reporting of crop injury in general, AAPCO,university researchers, and some growers state that they believe that these types of complaintstend to be underreported. EPA received feedback that underreporting could be associated with adesire to maintain good relationships with neighbors; fear that a damaged crop will be consideredadulterated and cannot be sold; fear that the grower will lose their organic certification; andgrower perception that no action will be taken in response to filing a report. Conversely, theremay have been issues of overreporting. The reasons provided included: damage was caused byuse of older more volatile formulations of dicamba or other chemistries; and damage reportsgiven in terms of acreage that reflects the size of an entire crop field and not just the portion ofthe crop field that was actually damaged.2018 Decision, Label Amendments, Conditions of Registration, and Expiration Date:On November 1, 2018, EPA granted Bayer’s requests to extend the expiration date for theirproduct registered for DT crop uses (EPA Reg. No. 524-617) for two years to December 20,2020. On November 2 and 5, 2018, EPA granted similar extension requests for BASF (EPA Reg.No. 7969-345) and DuPont (EPA Reg. No. 352-913), respectively. In each case EPA approvedamendments to the terms and conditions of the registration as well as adding labeling restrictionsto further reduce the potential for off-site movement of dicamba from the treated fields.Supporting documents and registration notices can be found on, Docket ID:EPA-HQ-OPP-2016-0187. This action was informed by input from state regulators, farmers,academic researchers, pesticide manufacturers, and other stakeholders. EPA reviewed substantialamounts of new information and concluded that the continued registration met FIFRA’sregistration standards. The Agency also determined that extending these registrations would notaffect endangered species.The additional labeling requirements for the 2018 dicamba OTT uses included the following:x a limit of two OTT applications of dicamba per field per year for both DT cotton and DTsoybeansx no applications to DT crops 60 days or later after planting cotton and 45 days or laterafter planting soybeans or until a specified crop growth stagex OTT dicamba applications only permitted between one hour after sunrise and two hoursbefore sunsetx applications may be made only by certified applicatorsx equipment clean-out requirementsx an omnidirectional application buffer to protect endangered species from off-targetmovement of dicambaEPA determined that these label changes would result in a minimal reduction of the flexibility ofgrowers to use dicamba as a tool for resistance management. EPA also determined that the8

labeling changes would further minimize the potential for off-site movement. New conditions ofregistration were also associated with this two-year extension. These included enhancedreporting and additional data requirements. This was a two-year registration set to automaticallyexpire on December 20, 2020, unless EPA further extended it.2019 New OTT Dicamba Product RegistrationOn April 5, 2019, EPA registered a product containing a combination of dicamba and Smetolachlor for OTT use on DT cotton and DT soybeans (EPA Registration Number 100-1623,A21472 Plus VaporGrip Technology (ABN Tavium)). This combination of active ingredientswas previously an approved tank mix, and as such, the combination of active ingredients wasalready being used as a tank mix for OTT on DT cotton and DT soybeans. The registration forthis dicamba product was set to automatically expire on December 20, 2020, unless EPAextended it.2019 IncidentsDuring the 2019 use season, based on reporting to AAPCO, there was an approximate 10%increase in number of incidents from 2018 with 1,218 reported in 2018 compared to 1,345incidents reported to the states in 2019. According to EPA’s Incident Data System, there were1,400 incidents reported in 2017, 2,600 reported in 2018 and nearly 3,000 reported to EPA in2019. Although, reports have continued to increase nationally, there is variability in numbers ofreports from individual. Some states (e.g., Kentucky, Missouri, Minnesota, Ohio) have seen adecrease.2020 Court OrderOn June 3, 2020, the Ninth Circuit Court of Appeals issued a decision in National Family FarmCoalition, et. al., v. EPA, 960 F.3d 1120 (aka Dicamba II), ordering the immediately effectivevacatur of three pesticide registrations containing the active ingredient dicamba for use on DTcrops (XtendiMax with Vaporgrip Technology (EPA Reg. No. 524-617); Engenia (EPA Reg.No. 7969-345); and FeXapan (EPA Reg. No. 352-913)). The Court found that EPA’s decision toapprove these dicamba products was not based on substantial evidence in that “EPA substantiallyunderstated risks that it acknowledged and failed entirely to acknowledge other risks.” Theproduct containing dicamba plus s-metolachlor (Tavium) was not vacated, so it remainedregistered with the expiration date of December 20, 2020.On June 8, 2020, EPA issued a cancellation order providing growers, commercial applicators anddistributors with direction on how to effectuate the vacatur. This cancellation order outlined thelimited and specific circumstances under which existing stocks of the three affected dicambaproducts could be used for a limited period of time. Growers and commercial applicators wereallowed to use existing stocks that were in their possession as of June 3, 2020, as long as the usewas consistent with the product’s previously approved label, but only until July 31, 2020.IV. 2020 Registration ActionsBayer and BASF submitted registration applications on July 2, 2020 for new productregistrations (XtendiMax and Engenia) for use on DT cotton and DT soybeans. Syngentasubmitted an application to amend its Tavium registration on August 12, 2020, including arequest that the upcoming expiration date be extended.9

The documents supporting the decision to grant these applications can be found in docket numberEPA-HQ-OPP-2020-0492 at In coming to its decision, EPA’s record includesconsideration of earlier submitted relevant studies and information as well as new studies andinformation received post the earlier registration actions. Therefore, some documents that wereconsidered in earlier registration actions are referenced in these new supporting documents.V. Stakeholder FeedbackThe Agency received comments from various stakeholders in the form of calls, emails, andletters concerning the use of dicamba on DT cotton and DT soybeans. The comments were bothin favor of and opposed to the continued or renewed registration of dicamba for pre- andpostemergent use on DT cotton and DT soybeans.Included in these comments was correspondence from a variety of stakeholders seeking to sharetheir experience with dicamba, including state agencies, farm bureaus, industry, growers, nongovernmental organizations, academia, congressional committees, and Members of Congress.These correspondences can be found in the document titled 2020 Dicamba Decision Commentson in Docket ID: EPA-HQ-OPP-2020-0492. The information provided differentviewpoints, and EPA considered these comments prior to approving these registration actions.Many letters representing significant economic sectors strongly encouraged EPA to register theseproducts. These letters indicated that growers need as many tools as possible and that dicambafor use in DT cotton and soybean is critically important to combat troublesome weeds (Palmeramaranth). Some of the letters provided information about the adoption rate of this technology asan indicator of importance to growers and how regulation can hamper the development of newtechnologies to help growers control weeds. As of October 19, 2020, examples of letters receivedwere from agricultural coalitions from the states of: Alabama, Georgia, Kansas, Mississippi,Nebraska, Virginia; seed dealers/Co-Ops: Beck’s Hybrids, LG Seeds, Wilbur-Ellis, Proseed,Latham High-Tech Seeds; commodity groups: National Cotton Council (NCC), AmericanSoybean Association (ASA), Georgia Cotton Commission, Plains Cotton Growers, AmericanSeed Trade Association; commercial applicator groups: Southern Crop Protection Association(SCPA); registrant representatives: Crop Life America; governmental entities: Iowa Departmentof Agriculture and Land Stewardship, Kansas Department of Agriculture, PennsylvaniaDepartment of Agriculture, the Governor of Nebraska, the U.S. House of RepresentativesCommittee on Agriculture, and Members of Congress; and state organizations: the NationalAssociation of State Department of Agriculture (NASDA) and American Association of PestControl Officials (AAPCO). There were also letters from various individuals, including oneacademic who stated that the DT system is an important tool, but there have been incidentsdespite mitigation measures, and additional control measures should be considered (Hartzler).Letters from other stakeholders provided varying details describing incidents and views on thenature of incident reporting, including possible underreporting. These letters describe damage tovineyards, non-DT soybeans, and numerous species of trees and other broadleaf herbaceousplants. These incidents were documented on small farms, residential areas, public lands (e.g.,parks, natural areas, wildlife refuges), industrial landscapes (e.g., cemeteries and business storefronts) and roadsides. Additionally, the issue of “right to farm” was raised (i.e., growers have the10

right to grow crops without concern for loss or damage to an organic or sensitive crop because ofoffsite movement of dicamba). In addition to concerns about effects to single-season crops,letters also cited concerns about long-term economic impacts of dicamba damage to orchards andvineyards. These letters were received from a coalition for specialty crop growers (Save ourCrops Coalition); non-governmental organizations: Audubon Arkansas, National WildlifeFederation, Prairie Rivers Network, The Land Connection, and Center of Food Safety; a stateorganization: American Association of Pest Control Officials (AAPCO); and variousindividuals.VI. Risk AssessmentsA. Human HealthThe potential for human health risks from OTT uses of dicamba was first assessed in March2016 9. At that time, EPA found the toxicology database for dicamba complete and sufficient forassessing the toxicity and characterizing the hazard of dicamba.In 2020, EPA became aware of mutagenicity studies not previously submitted as well as a newdicamba epidemiology study conducted as part of the Agricultural Health Study (AHS). 10 TheAHS study reported an association between dicamba exposure in pesticide applicators andincreased risk of liver and intrahepatic bile duct cancer. EPA reviewed this study and identifiedseveral deficiencies. EPA notes an earlier incident/epidemiological memorandum 11 that revieweda study which investigated cancer incidence among pesticide applicators exposed to dicambawhich concluded that “Exposure was not associated with overall cancer incidence nor were therestrong associations with any specific type of cancer.” The AHS study does not alter EPA’searlier findings because it does not provide any additional information, therefore, the EPAhuman health risk conclusions for dicamba remain unchanged since the original assessment in2016.Several additional studies addressing dicamba mutagenicity were also reviewed in 2020,including two comet assays, a kinetics assay, and a transgenic mouse assay. The results do notimpact or change the current cancer classification or risk conclusions for dicamba, which aresummarized in the document Dicamba: Consideration of Newly Submitted Mutagenicity Data andHuman Health Risk Assessment Summary (available on, Docket ID: EPA-HQOPP-2020-0492). Because there was no change in EPA’s cancer classification as “Not Likely tobe Carcinogenic to Humans,” EPA determined that no additional human-health focused controlmeasures were necessary for these actions.B. Ecological9See Dicamba and Dicamba BAPMA Salt: Human Health Risk Assessment for Proposed Section 3 New Uses onDicamba-tolerant Cotton and Soybean (available on, Docket ID: EPA-HQ-OPP-2016-0187)10See Dicamba: Tier I (Scoping) Review of Human Incidents and Epidemiology (available on,Docket ID: EPA-HQ-OPP-2016-0223)11

A summary of the environmental fate and ecological effects, and potential environmental risksfrom the pre- and postemergent uses of dicamba on DT cotton and DT soybeans is providedbelow. The full assessment can be found in EPA’s 2020 Ecological Assessment of Dicamba Useon Dicamba-Tolerant (DT) Cotton and Soybean Including Effects Determinations for FederallyListed Threatened and Endangered Species (available on, Docket ID: EPA-HQOPP-2020-0492).The ecological assessment for these registration actions included a screening-level riskassessment for the pre- and post-emergent uses of dicamba on DT cotton and DT soybeans. TheAgency also included species-specific assessments for threatened and endangered (hereafterreferred to as “listed”) species present within the 34 states approved in these registration actions(Alabama, Arizona, Arkansas, Colorado, Delaware, Fl

Oct 27, 2020 · the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), three end use dicamba products for use on dicamba tolerant (DT) cotton and soybeans. Bayer and BASF submitted registration applications on July 2, 2020 for new registrations of XtendiMax and Engenia for use on DT cotton and DT soybeans.