UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460

OFFICE OF PREVENTION, PESTICIDES
AND TOXIC SUBSTANCES

By Mail

Jennifer Sass September 30, 2008

Natural Resources Defense Council 1200 New York Avenue, NW

Suite 400 Washington, DC 20005

Re: NRDC’s comments on the Carbaryl IRED and petition to cancel registrations dated January 10, 2005 as well as petition to cancel carbaryl registrations dated November 26, 2007 and submitted as part of NRDC’s comments to N-methyl carbamate cumulative.

Dear Dr. Sass:

This letter constitutes a partial response to the petition dated January 10, 2005 (Petition) submitted by the Natural Resources Defense Co uncil (NRDC) requesting, among other things,

that the Environmental Protection Agency (EPA or Agency) revoke all tolerances and cancel all registrations for carbaryl. As a preliminary matte r, it should be noted that NRDC’s submission is in the form of comments on and requests for changes to the Carbaryl Interim Reregistration Eligibility Decision (IRED) publis hed in the Federal Register on October 27, 2004 (69 Fed. Reg. 62,663). Nonetheless, in the in troduction to the comments, NRDC included a statement that NRDC is also petitioning the Agency to revoke all carbaryl tolerances and cancel all carbaryl registrations. Because of this statement in the introductory paragraph, EPA is responding to this submission as a petition rather th an in a response to comments document. However, the Petition

contains a number of asserti ons that constitute comments a nd that do not provide a basis upon which to either cancel all carbaryl registrations or revoke all carbaryl tolerances. This letter also serves as a partial response to NRDC’s reassertion of its Petition request submitted as part of NRDC’s comments on the N-methyl carbamate cumulative assessment and dated November 26, 2007 (NMC Petition).

I. Legal Framework

EPA regulates pesticides under both the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and the Federal Food, Drug, and Cosmetic Act (FFDCA). FIFRA sets forth a federal licensing scheme for the sale, distribution a nd use of pesticides; FFDCA establishes the mechanism and standards by which EPA sets to lerances establishing allowable levels for pesticides in food. As a general matter, unde r FIFRA Section 3, before a pesticide can be

distributed or sold in the Un ited States, it must be registered by EPA. FIFRA Section 6 authorizes EPA to cancel pesticide registrations that do not comply with FIFRA and, in certaincircumstances, to suspend those registrati ons pending the completion of cancellation proceedings. Registration decisions related to no n-dietary risks are govern ed by a “risk-benefit” standard; in order for EPA to register a pesticide, it must not pose “any unreasonable risk to man or the environment, taking into account the economic, social, and environmental costs and benefits of the use of any pesticide.” FIFRA §§ 2(bb) and 3(c)(5). This response only addresses non-dietary risk issues (dietary risk issues are being addressed in EPA’s response to the Petition to revoke carbaryl tolerances); whenever risks are being discu sses in this document, we are referring to non-dietary risks.

Because FIFRA imposes a risk-benefit standard, EPA’s decision to grant a registration (or find that a pesticide is eligible for reregistration) is not simply a matter of wh ether there are risks of concern, but rather whether those risks are reas onable in light of the benefits. In making pesticide registration decisions, EP A first typically looks to determ ine whether a particular use of an active ingredient poses a meaningful risk (often referred to as a “risk of concern”). If a use does not pose a risk of concern or if EPA concludes that its asse ssment overstates the risks such that the Agency determines the use will not cause any meaningful risk, EPA generally finds the use to be an acceptable one without looking at the be nefits associated with the use. If the use does pose a risk of concern (either at first examination or upon further refinement of the risk estimate), EPA determines whether changes to th e terms and conditions of use of the pesticide registration can feasibly and effectively mitigate th e risk to acceptable levels. These changes can include changes to the di rections for use on the product’s labe l (such as changes in application rates and methods, extending restricted entry tim es, requiring buffer zones where the pesticide may not be applied, or requiring protective clothing or equipment) , or they can include changes to the pesticide’s formulation or packaging. If these changes are adopted voluntarily by a registrant, the use is then gene rally found to be acceptable. If a registrant does not agree to changes to the terms and conditions of a registra tion, or if effective changes cannot reasonably be implemented, the Agency then must determine wh ether the risks associat ed with the use are justified by the benefits associated with that use. If the Agency determines that cost-effective changes to the terms and conditions of registration are appropriate, or if the risks a ssociated with the use are not justified by the benefits associ ated with that use, the Agency will initiate appropriate regulatory action unde r FIFRA section 6 unless the necessary changes (if any are possible) are made by the registrant. If, on the other hand, the Agency dete rmines that the risks associated with a use are justified by the benef its, and no cost-effective ch anges to the terms and conditions of registration can be identified to mitig ate those risks, the use would continue to meet the FIFRA standard for registration.

EPA decisions under section 408 of the FFDCA, on the other hand, are made through application of a risk-only safety standard. FFDCA §408(b)(2)(A) re quires that the Agency make a finding that there is a “reasonabl e certainty of no harm” for each use of a pesticide associated with a pesticide tolerance. Where uses raise ri sk issues that are rele vant under both FIFRA and the FFDCA, such as residential risks (which must be aggreg ated with dietary risks in determining whether a tolerance meets the FFDCA standard), EPA first looks to see whether

tolerances meet the “reasonable ce rtainty of no harm” standard. If affected tolerances meet this safety standard, the risks addressed in that dete rmination would generally be considered to be acceptable without further mitigation required under FIFRA. If tolerances of a particular pesticide (or group of pesticides that share a common mechanism of toxicity) do not meet the safety standard, EPA must then determine whet her to revoke or modify some or all of the

- 2 -tolerances relevant to that de termination or, if possible and ap propriate, take act ion under FIFRA to mitigate relevant risks so that any remaining toleran ces meet the section 408 standard.

A. Reregistration Eligibility Decisions

In 1988, Congress amended FIFRA Section 4 to incl ude a specific, five-phase process for the “reregistration” of pesticides containing any active ingredient c ontained in any pesticide first registered before November 1, 1984. Pub. L. 100-532, tit. I, § 102(a), 102 Stat. 2655, 2683 (1988). In the fifth phase, EPA wa s required to review all the st udies that have been submitted by the pesticide registrants for a pesticide active ingredient, as we ll as other relevant information, and decide whether or not pesticides contai ning the active ingredient (s) are “eligible” for reregistration under the risk-benefit standard in FIFRA Section 3(c)(5). After determining eligibility of the activ e ingredient, EPA must determine whether products containing these active ingredients and inert ingredients meet the risk-b enefit standard in FIFRA Section 3(c)(5) and are eligible for reregistration under FIFRA § 4(g)(2)(B ). To memorialize its reregistration decision, EPA typically issues a Reregistration Eligibili ty Decision (“RED”) document for each pesticide active ingredient being considered for reregistration. Before issui ng a RED, EPA’s practice is to engage in a public participati on process with various opportun ities to comment (although FIFRA does not require such a commen t opportunity) on the development of the risk assessments and risk mitigation that form the basis for the RED. When EPA issues a RED, it also typically issues a “data call-in” (DCI) un der section 3(c)(2)(B) of FIFRA to acquire any needed product-specific data for the actual pesticide produc ts that contain the active ingred ients addressed in the RED. Following submission and review of these data a nd revised pesticide pro duct labels, EPA must determine whether to reregister these products according to the FIFRA risk-benefit standard or take appropriate regulatory action. FIFRA § 4(g)(2)(D).

B. Interim Reregistrati on Eligibility Decisions

In 1996, the Food Quality Protection Act (“ FQPA”) was enacted, amending FFDCA and FIFRA to require all pesticides whose use results in residues on food to meet new dietary risk standards. The FQPA also amended the FIFRA ri sk-benefit standard (“a ny unreasonable risk to man or the environment”) to add another element to the definition of that term: “a human dietary risk from residues that result from a use of a pe sticide in or on any food inconsistent with the standard under [FFDCA Sec tion 408].” FIFRA § 2(bb).

FFDCA Section 408 requires EPA to establish, by regulation, toleran ces (maximum legally permissible levels) for pesticide residues in f oods. FFDCA § 408(b)(1). In other words, both registration and reregistration of a pesticide is contingent upo n its meeting the food safety

standard established under FFDCA Section 408 if use of the pest icide results in residues on food. When establishing, modifying, leaving in effect, or revoking the tolerance for a pesticide, EPA is required to consider whether there is a “reas onable certainty that no harm will result from aggregate exposures to the pesticide chemical residue . . . .” FFDCA § 408(b)(2)(A)(i). In conducting this assessment, EPA is required to co nsider, among other relevant factors, available information concerning the cumulative effects of su ch residues and other substances that have a common mechanism of toxicity applicable prot ecting human health. In its assessment, EPA

considers the risks associated with the pesticide from aggreg ate exposures to residues on food

- 3 -and in drinking water as well as exposure from non-occupational uses (e.g ., home and garden). Aggregate exposure encompasses exposures to ot her related substances, including substances

that share a common mechanism of toxicity with the pesticid e. FFDCA § 408(b)(2)(D)(v)-(vi). These “other” substances sharing a common mechanism of toxicity can and do include other pesticides. 1 When EPA determines that a pesticide sh ares a common mechanism of toxicity with other substances, EPA cannot complete either the assessment or reassessment of a tolerance or a registration or reregistration determination until it has assessed available information regarding exposures to the other substances . In some instances, cumulative exposure assessments can take many years to complete – especially for those pe sticides that may share a common mechanism of toxicity with a particularly larg e number of chemicals. For these pesticides, EPA’s practice is to issue an Interim RED (“IRED”) pending completion of the tolerance reassessment activities. As it customarily does with REDs, EPA generally a ffords the public an opportunity to comment on

an IRED when it is issued. 2 EPA often issues a mandatory call- in for data with the IRED. EPA uses DCIs to gather additional data to support reregistration decisions. An IRED memorializes EPA’s determination on a narrowly defined issue: whether a given active ingredient alone is eligible for reregistration under FIFRA Sec tion 4, pending a cumulative assessment for pesticides sharing a common mechanism of toxicity. Often, IREDs delineate mitigation measures that would enable pesticide produc ts to be eligible for reregistration.

II. Background

On June 30, 2003, the Agency completed an IRED for carbaryl, which was subsequently posted on EPA’s web site for public viewing. EP A published and made available for comment a revised IRED on October 27, 2004 (2004 Revised IR ED or Carbaryl IRED). NRDC submitted

its comments on the 2004 Revised IRED on Januar y 10, 2005. In the introductory paragraph of their comments, NRDC included a statement that NR DC is also petitioning the Agency to revoke all carbaryl tolerances and cancel all carbary l registrations. Insofa r as NRDC’s comments purport to be a petition to revoke all carbaryl tolerances , the Agency published a notice of receipt of the petition to revoke all carb aryl tolerances for comment in the Federal Register on March 30, 2005. (70 Fed Reg 16,281).

In March 2005, EPA also issued generic and product- specific data call-ins (DCIs) for carbaryl. The generic DCI required several studies for the active ingredient carbar yl, including additional toxicology, worker exposure monitoring, and envi ronmental fate data. The product DCI required acute toxicity and product chemis try data for all pesticide products containing carbaryl. EPA has

received numerous studies in re sponse to these DCIs, and, where appropriate, these studies have been considered in the revised risk assessments for both the N-methyl carbamate cumulative and for the carbaryl RED.

In response to the DCIs, many carbaryl registrant s chose to voluntarily cancel their carbaryl products. One technical regist rant, Burlington Scientific, ch ose to cancel their technical

1 Carbaryl is an N-methyl carbamate pesticide. N-methyl carbamate pesticides have been determined to have a common mechanism of toxicity in the cont ext of assessing human health risks.

2 Although FIFRA requires EPA to determine whether pestic ides are eligible for reregistration and to request the submission of additional data, EPA’s pr actice of preparing a RED or IRED ex tends above and beyond its statutory obligation.

- 4 -product, 3 leaving Bayer CropScience (Bayer) as the sole technical regist rant for carbaryl. Approximately two-thirds of all of the carbaryl end-use products registered at the time of the initial carbaryl IRED (June 2003) have been canceled thr ough this process. 4

In June 2006, EPA determined that the uses associated with 120 of the existing carbaryl tolerances are not signif icant contributors to the overall N-methyl carbamate (NMC) cumulative

risk and that these tolerances had no effect on the retenti on or revocation of other NMC tolerances. Therefore, EPA considered these 120 tolerances for carbaryl as reassessed on June 29, 2006, and posted this decisi on on the internet site, http://www.epa.gov/pesticides/cumulative/carbamates commodity.pdf . On June 29, 2006, EPA also published a preliminary NMC cumulative risk assessment.

In late November 2006, EPA received data fr om a carbaryl comparativ e cholinesterase study, conducted to determine the comparative sensitivit y of adults and offspring to cholinesterase inhibition by carbaryl. These data were used to revise the FQPA sa fety factor for carbaryl for the

NMC cumulative risk assessment and to select new toxicology endpoints ( points of departure) for the risk assessment. The Agency determined that it was appropriate to use the new FQPA safety factor and revised points of departure in both the NMC cu mulative risk assessment and the carbaryl-specific human health risk assessment. Because this necessitated a revision of the carbaryl human health aggregate risk assessment, EPA also considered additional new data generated in response to the DC I, new methodologies, and other new information in performing

its most recent assessment of carba ryl and in responding to this Petition.

On September 26, 2007, EPA published a Notice of Availability for the NMC cumulative assessment and opened a 60 day public comment period on the cumulative assessment (72 Fed. Reg. 54,656). In conjunction with the NMC cumulative assessment, on September 24, 2007, EPA completed the carbaryl RED, which amended s ections of the previously issued Carbaryl IRED based upon new data generated in response to the March 2005 DCI, a revised FQPA safety factor for carbaryl used in the NMC cumula tive assessment, new methodologies, and other new information. The carbaryl RED was formally is sued on October 17, 2007, with the publication of a Notice of Availability in the Federal Re gister (72 Fed. Reg. 58,844). EPA subsequently completed an addendum to the carbaryl RED, dated August 25, 2008, which incorporated the results of a revised occupational risk assessment and modified mitigation measures for the protection of workers.

III. Petition Response

To the extent that the carbaryl RED and revise d ecological and occupational and human health

risk assessments are not inconsistent with th e reasoning in the various responses to NRDC’s Petition, EPA relies on those documents as well in responding to NRDC ’s Petition to cancel carbaryl registrations.

3 EPA published a notice of receipt of a request for cancellation in the Federal Register on October 28, 2005 (70 Fed Reg 62,112), followed by a cancellation order issued on July 3, 2006.

4 Of approximately 300 carbaryl products registered in 2003, 208 product registrations have been canceled, and 4 products have been suspended for failure to submit required product chemistry data.

- 5 -In terms of the issues addressed in this portion of EPA’s response to NRDC’s Petition, a

number of the issues raised in the Petition were based upon the Ca rbaryl IRED and have either been addressed in subsequent revisions or are no longer applicable. In any event, the following is EPA’s response to the issues raised in the Petition and the NMC Petition relevant to NRDC’s contention that all carbaryl regi strations should be cancelled for re asons unrelated to whether the carbaryl tolerances meet the safety standard of FFDCA section 408.

A. Occupational Risks.

NRDC raises a number of issues related to EPA’s occupational assessment. NRDC “recommends” that all uses be cancelled where margins of exposure (MOEs) are less than 100 for occupational exposures. Specifically, NRDC argues that since EPA has not provided an adequate benefits justification for these uses, all of them should be cancelled. In addition,

NRDC recommends that restricted entry intervals (REIs) be set so that the MOE is at least 100 for high exposure post-application tasks. NRDC further “recomme nds” that EPA re-calculate its acceptable exposure levels, incorporating data fr om “recorded” worker exposure events for both handlers and post-application workers, includ ing information regarding a 2003 incident in Florida and 2004 cholinesterase (ChE) medical m onitoring data from Washington State. In so doing, NRDC argues that carbaryl is toxic and causes ChE inhi bition at occupational exposure levels that EPA currently considers “safe,” ev en when carbaryl is used in accordance with

current label directions.

NRDC further criticizes EPA’s use of the Agricultural Re-Entry Task Force (ARTF) data, objecting to its use and requesting that EPA refrai n from further use of this information until it has been fully evaluated by the FIFRA Scientific Advisory Panel (SAP) and subjected to public notice and comment. Among other things, NRDC asserts that EPA’s ri sk calculation methods underestimate occupational risk.

1. Worker scenarios.

NRDC identifies a number of speci fic agricultural scenarios for which the MOEs are less than

100 in the 2004 Revised IRED. 5 NRDC also identifies a number of re-entry scenarios where the

MOE is less than 100 at the time of REI esta blished by the IRED. NRDC then mistakenly

asserts that EPA has determined that MOEs of 1 00 or greater are “required” to ensure worker safety for short or intermediate term exposures . To the contrary, there may be circumstances where an MOE of less than the target number are acceptable. For example, where a use scenario has high benefits, where worker risk has been mitig ated to the extent practical and feasible, or

where EPA is confident that worker risks are ove restimates, an MOE of less than the target may

5 For occupational risk assessments of threshold effects, the risk estimate is expressed as an MOE, which is compared with an MOE representing an exposure level that is considered to be not of concern. An MOE that is not of concern is generally considered to be a value greater than or equal to the pr oduct of all applicable safety factors for a pesticide. For example, if a pes ticide needs a 10X factor to account for interspecies differences and 10X factor for intraspecies differences, the level of concern (LOC) would be an MOE of 100. To calculate the MOE for a pesticide, the lowest no observed adverse effect level (NOAEL) or point of departure (PoD) from the available studies is typically divided into human exposure to the pes ticide. The higher the MOE, the less concern there is for a pesticide. Accordingly, if the LOCfor a pesticide is an MOE of 100, MOEs exceeding 100 would generally not be

of concern.

- 6 -be acceptable. Nonetheless, in this case, as reflected in EPA’s 2007 revised occupational risk assessment and 2008 addendum to the carbaryl RED, the MOEs for all but one of the pesticide handler scenarios are now equal to or greater than the level of c oncern (an MOE of 100) with the mitigation specified. Further, post-application MOEs for re-entry workers are now ≥ 100 on the day of carbaryl application 6 for the vast majority of crops and worker re-entry scenarios. EPA’s

current MOE estimates for workers consider the mitigation established in the 2004 Revised IRED, exposure monitoring data 7 submitted for carbaryl, and revised toxicological endpoints (points of departure) fo r risk assessment. See Carbaryl: Revisions to Occupational Exposure

and Risk Assessment , for details 8 (“2007 revised occupational assessment”).

In the 2007 revised occupational assessment for carbaryl, the only handler scenario assessed by EPA that resulted in MOEs of less than th e LOC of 100 was for an aerial application of a carbaryl bait formulation to control grasshoppers and Mormon crickets, which migrate in swarms and generally consume large amounts of vegetativ e matter in their path. These are serious episodic pests in the Western United States; in addition to causing severe crop loss, swarms of migrating insects decrease visibility to such an extent that they can cause automobile accidents. (See comments and photographs, EPA-HQ-OPP-2005-0077-26 and 29).

The applicator MOE for this scenario is 36. Howe ver, the Agency believes that this value does not represent an unacceptabl e level of risk. First, the worker exposure estimate for this scenario is based upon data for a typical granular formulati on, which consists of a carrier that releases the pesticide active ingredient when the formulati on is applied. Carbaryl bait products used for grasshopper and Mormon cricket suppression consis t of large extruded pellets composed of a homogenous blend of the pesticide active and in ert ingredients. These pellets are tightly compressed, and not intended to release the activ e ingredient when the product is applied; instead, the entire pellet is in tended to be consumed by the target pest. Second, the calculated exposures could overestimate risks because of the high number of acres considered in the

assessment and the bias that occurs with such extrapolations. Moreover, the RED addendum specifies that for aerial applicati on of carbaryl bait products, aircraftmust have enclosed cockpits that are completely separate from the bait bins and the air intake vents for the cockpit must be located above the bait bins. (See 2008 RED addendum at 24). In addition, the carbaryl bait product is applied by highly trained handlers who ar e affiliated with state or Federal grasshopper and Mormon cricket suppression programs to furthe r ensure proper use of the material. Finally, this is a high benefit use; car baryl baits are the most effectiv e pesticide product available to control both juvenile and adult grasshoppers a nd Mormon crickets which are severe pests in Western states. Thus, even if the MOEs are less than 100 for this use, EPA has concluded that the associated risks are not significant, and EP A has further determined that those risks are justified by the benefits for this particular use.

6 MOEs are ≥ 100 at 12 hours, indicating that the REI can be set at 12 hours for most crops and worker re-entry

scenarios.

7 As part of the Generic Data Call-in , EPA received three occupational handler studies. EPA determined that two were acceptable: (1) Determination of Dermal and Inhalation Exposure to Workers during Application of a Liquid Pesticide Product by Open Cab Airblast Application to Orchard Crop s. (MRID 464482-01) and (2) Determination of Dermal and Inhalation Exposure to Workers during Closed-System Loading and ULV Application of a Liquid

Pesticide Product to Cotton .. (MRID 46634105).

8 US EPA. Office of Pesticide Programs. 2007. Carbaryl: Revisions to Occupational Exposure and Risk

Assessment. July 9, 2007.

- 7 -In the 2007 revised occupational as sessment, all but two re-entry scenarios resulted in MOEs > 100 at the post-application time for the REI esta blished by the 2004 IRED. Therefore, many of these REIs will be adjusted to reflect the findings of the revised occupational assessment. One

scenario with MOEs < 100 is for workers hand-h arvesting cut flowers on the day of application (MOEs from 23 - 48) in regions where rainfall is < 25 inches per year (i.e., west of the Mississippi River). The MOE fo r cut flowers reaches 100 on day 18 after carbaryl application; therefore, EPA is establishing an REI of 18 days for cut flowers, including ornamentals grown for cuttings, where production is in outdoor areas where annual rainfall average is less than 25 inches per year. The second scenario involves workers conducting very high contact activities of grape cane turning and girdling (MOE of 31 on th e day of carbaryl application), which did not reach 100 until 6 days after application. Howe ver, these MOEs are for very high contact activities which generally only occu r in grape culture west of th e Rocky Mountains. Therefore, for grapes grown east of the Rocky Mountains , EPA is maintaining an REI of 48 hours and prohibiting the very high contact activities of can e turning and girdling until 6 days after carbaryl application. The REI for grapes grown west of th e Rocky Mountains is established at 6 days for all reentry activities.

Finally, NRDC mentions use scenarios where the IRED did not present MOEs due to a lack of data (i.e., animal grooming dust applications, dust applications in agriculture, hand-held fogger, power backpack sprayer, dipping/drenching seedli ngs, and tree injection). EPA found the animal grooming use ineligible for reregistration in the IRED, and this use was subsequently canceled. EPA required worker exposure monitoring studies for the remaining scenarios lacking data to derive MOEs in the March 2005 Generic DCI, which was sent to the two sole technical registrants of carbaryl, Bayer and Burlington Sc ientific. In response to the DCI, Burlington Scientific submitted a request to voluntarily can cel their registration for carbaryl technical pursuant to FIRFA section 6(f). EPA published a notice of receipt of this request in the Federal Register on October 28, 2005 ( 70 Fed. Reg. 62,112), followed by a cancellation order issued on July 3, 2006. Bayer, the sole remaining technical registrant responsible for developing data, requested waivers of these studies because these use scenarios are not on any Bayer technical or product labels (or were to be dele ted from Bayer labels). Bayer subsequently requested that all of their carbaryl registrations bearing any of these uses be amended to delete these uses. 9 EPA published a Notice of receipt of this request in the Federal Re gister on August 20, 2008 (73 Fed. Reg. 49,184), and plans to approve Bayer’s request and issue a final order amending these registrations at the end of th e comment period for the Notice. The Bayer product registrations will be formally amended to delete these us es by December 31, 2008. Because Bayer is not developing data to support the use scenarios mentioned above, EPA does not have sufficient information to reregister produc ts bearing these uses on curren t labels, and cannot find these products eligible for reregistration unless the uses are deleted from product labels. Therefore, EPA has notified all affected registrants that thes e uses and application methods must be deleted from their carbaryl product labels. EPA has identified 54 product labels from 14 registrants (other than Bayer) bearing these end uses. All of these registrants have requested that their affected carbaryl product registrations be amende d to delete these uses. EPA published the first Notice of Receipt of these requests from 12 regist rants representing 45 products in the Federal Register on August 20, 2008. EPA expects the sec ond Notice of Receipt covering the remaining

9 August 4, 2008 letter from Danielle LaRochelle, Bayer CropScience to EPA’s Office of Pesticide Programs, Special Review and Reregistration Division.

- 8 -3 registrants and their 9 products to be published in the very near future. The Agency plans to approve these requests after their respective comm ent periods close.

2. Worker exposure incidents.

NRDC claims that EPA failed to consider ac tual worker poisoning events at occupational exposure levels that EPA considers to not be of concern. NRDC recommends that EPA recalculate its acceptable exposure levels, incorpor ating data from “recorded” worker exposure events for both handlers and post-application workers. Specifically, NRDC insists that EPA

failed to consider an incident that occurred in Florida. Similarly, NRDC claims that EPA failed to consider monitoring data from Washington State, asserting that carbaryl is toxic and causes ChE inhibition even when used according to the label instructions.

In response to requests from NRDC, Farmwork er Justice, and other stakeholders, EPA’s Office of Pesticide Programs prepared a report on the use of incident data in the pesticide program. This report was presented to the Pe sticide Program Dialogue Committee (PPDC) at its October 17, 2007 public meeting. This document, OPP Report on Incident Information: The

Baseline (“PPDC Incident Report”), may be foun d on EPA’s website at the following URL: http://www.epa.gov/oppfead1/cb/ppd c/2007/oct2007/sessio n10-finalrpt.pdf

As explained in detail in the doc ument prepared for the PPDC, incident data provide valuable qualitative information to EPA and available data are used in the Agency’s regulatory decisions. For example, incident data may provide a perspe ctive on potential risks of a pesticide compared to other pesticides with a similar use. Incident data may be used to confirm the effectiveness of risk mitigation measures, or indicate where additional mitigation is needed, such as a change in product packaging. Likewise, human incident data may indicate pesticide misuse and the need for enforcement action. Furthermore, worker inci dent data may indicate where additional worker outreach and training are needed to increase aw areness and understand ing of safe use of pesticides. However, most incide nt data have limitations that pr event their use in quantitative risk assessment, as requested by NRDC.

a) Florida incident

NRDC asserts that EPA failed to consider an alle ged carbaryl incident that occurred in Florida in April 2003. Specifically, on April 9, 2003, 21 fa rm workers were taken to emergency rooms of two hospitals near Duette, FL , after a number of harvesters (14) complained of difficulty breathing, headaches, dizziness, and nausea. Two work ers appeared to be more affected than the others. One worker reported continuing symp toms for weeks after the incident and was ultimately successful in bringing a Workman's Co mpensation claim related to this incident. NRDC asserts that a finding by a Florida work man’s compensation judge is incontrovertible evidence that carbaryl was in fact the cause of the worker’s injuries. Thus, NRDC argues that EPA failed to consider that actual worker “p oisonings” occur at occupational exposure levels that EPA currently considers “safe” when establishing REIs for carbaryl.

First, EPA did consider the Florida incident. In fact, EPA conducted its own investigation and assessed reports and investigatio ns conducted by the Florida Depa rtment of Health, which is

- 9 -affiliated with the NIOSH SENSOR 10 Program, and the Florida Department of Agriculture and Consumer Services. Second, EPA disagrees that the “findings of fact” made by an administrative judge based upon the preponderance of the evidence considered in the particular preceding before him is dispositive for purposes of a rigorous risk assessment grounded in

scientific data. 11 Third, based upon the aforementioned inve stigations combined with what is known about the field conditions, worker activities, the toxicity of carbaryl, the carbaryl residue levels in the groves, and the f act that the symptoms were rela tively non-specific (and could fairly be attributed to other causes), it does not appear that the incident is directly related to a labeled use of carbaryl. Indeed, based upon its assessmen t of carbaryl, EPA does not believe that the

cause of the incident could have been use of car baryl in accordance with th e label. Fourth, even if carbaryl had been the cause of this incident, the reduced applic ation rates and REI specified in the IRED and the RED addendum provides additional assurance that this situation will not be repeated when carbaryl is used in acco rdance with the label instructions.

EPA’s Region 4 Office in Atlanta, Georgia, had th e lead for the Agency’s investigation of the

worker incident that occurred in Florida in April 2003 among workers of Dunson Harvesting Company that was allegedly attributed to expos ure to carbaryl. EPA Headquarters staff were also involved in all stages of the investigation, which began in April 2003 when the Agency received media reports of the incident. Bayer, the carbaryl registrant, submitted a report of the incident on May 29, 2003, as required under FIFR A Section 6(a)(2) (the adverse effects reporting provision). 12 When EPA initially completed the carbaryl IRED in June 2003, the investigations of both the Flor ida Department of Health a nd the Florida Department of Agriculture and Consumer Servi ces (DACS) were underway and neither agency had drawn any conclusions other than Dunson Harvesting had violated the Worker Protection Standard. 13 The Florida DACS completed its report on the analysis of residues on citrus foliage and estimated exposure to the workers harvesting citrus on Au gust 15, 2003; the report c oncluded that exposure to carbaryl would not be responsible for acu te toxicity to work ers under the conditions

evaluated. 14 Although carbaryl residues were meas ured on citrus foliage, neither EPA nor

Florida DACS could determine whether these resi dues were consistent with the SevinTM 80S label. The Florida Department of Health, Pesticide Surveillance Unit, completed its investigation in August 2004, conc luding that there was a possi ble association between the symptoms of 18 of the 21 affected workers and carbaryl exposure, but there was insufficient

10 NIOSH, National Institute for Occu pational Safety and Health, Sentinel Event Notification System for Occupational Risks. The NIOSH SENSOR program is designed to monitor occupational poisonings via community environmental health personnel in various locations throughout the United States, including Universities and State Departments of Health.

11 The EPA Region 4 case file summary addresses the speci fic issues raised by the pleadings in the workman’s compensation court case in more detail. See: Corb ett, Richard and Jeanneane Gettle, EPA Region 4. Case File Summary [for] Farm-OP 64, Duette, FL. April 20, 2005.

12 Wolford, Valerie. Bayer Crop Science. 6(a)(2) report re: SEVIN TM Brand Carbaryl Insecticide. Letter to EPA, Office Of Pesticide Programs. May 29, 2003.

13 The Florida Department of Agriculture and Consumer Services, Bureau of Compliance Monitoring, issued a citation to Dunson Harvesting on June 25, 2003, for violations of the Federal Worker Protection Standard.

14 Daiker, Davis. Florida Department of Agriculture and Consumer Services. Division of Agricultural Environmental Services, Bureau of Pestic ides, Scientific Evaluation Section. Data Interpretation/Risk Assessment Regarding Potential Carbaryl Incident in Manatee County . August 15, 2003.

- 10 -information for the remaining 3 workers to make an association. 15 The Florida Department of Health based its analysis on a comparison of symptoms reported by the Dunson Harvesting Company workers with typical symptoms associat ed with carbamate poisoning. However, there are other possible causes of such symptoms, a nd the pesticide applica tion records, carbaryl product labels in effect, and measur ed carbaryl residue levels on citr us foliage at the site of the incident do not support a cause and effect relatio nship between the application of carbaryl and the symptoms reported by the workers. EPA co mpleted its investigation in spring 2005; the results of this investigation were shared by th e Director of EPA’s Office of Pesticide Programs with representatives of NRDC and Farmworker Jus tice at a meeting held in August 2005.

The major confounding factor with respect to the effects reported by the workers is that the information available to the various agencies investigating the case was very limited. To establish worker exposure to carbaryl, clothing of the ill workers should have been analyzed for carbaryl residues. However, the Hazardous Mate rials (HAZMAT) team that responded to the incident on April 9, 2003, removed and destro yed workers’ clothing as part of the decontamination process; therefore, the clothi ng was unavailable for analysis for pesticide residues. In addition, worker blood ChE levels taken within one or two hours of worker exposure could corroborate exposure to a carbamat e pesticide such as carbaryl. However, blood samples taken from the affected workers to measure ChE levels were taken several hours after exposure, and therefore were likel y to have been too late to de tect any effects from carbaryl. 16
Consequently, an analysis of blood samples fo r ChE depression did not confirm or rule out carbaryl exposure. Last, the presence of the carbaryl biomarker N -napthol in the urine of affected workers could have confirmed exposur e; however, no urine samples were collected

from the workers to measure levels of this biomarker.

No new data in regard to this incident have been submitted. Thus, the information available to the Agency does not appear to support a conclu sion that the severity of symptoms reported by Florida citrus harvesters in April 2003 can be attributed to carbaryl exposure resulting from

contact with foliar residues. EPA will continue to monitor reports of worker incidents with pesticides including carbaryl . EPA notes that the Florida DACS issued a citation 17 to the company that employed the harvesters for a viol ation of the Worker Protection Standard for a violation of the training requireme nts of the Worker Protection Sta ndard and Florida state law. Florida determined that several of the injured workers had not been trained on how to protect themselves from exposure to pesticides.

b) Washington State Cholineste rase Monitoring Program

15 Becker, Alan. Florida Department of Health, Bu reau of Community Environmental Health, Pesticide Surveillance Program. Powerpoint slides on occupationa l exposure to carbaryl and April 9, 2003 Florida farm worker incident. August 16, 2004.

16 According to the handbook, Recognition and Management of Pesticide Poisonings (5 th Edition,1999) , “...unless a substantial amount of N-methyl carbamate has been absorbed and a blood sample is taken within an hour or two, it is unlikely that blood cholinesterase levels will be found depressed. Even under the above circumstances, a rapid test for enzyme activity must be used to detect an effect, because enzyme reactivation occurs in vitro as well as in

vivo .”

17 Bronson, Charles (Florida Commissioner of Agriculture). Administrative Complaint and Warning Letter to Dunson Harvesting . June 25, 2003.

- 11 -NRDC takes issue with the fact that EPA did not include worker ChE monitoring data from Washington state in the Carbaryl IRED. NRDC claims that these data demonstrate that carbaryl causes ChE inhibition even when used according to the label instructions. The Agency was

unable to consider the data from the Washington State cholineste rase monitoring program for the Carbaryl IRED because the data were not availabl e for EPA to review. However, since the data first became publicly available in January 2005, the Agency has closely followed the annual results from the Washington ChE monitoring prog ram and considered whether it had any impact on the carbaryl decision. Accordingly, any reque st to cancel carbaryl registrations based upon EPA’s alleged failure to consider ChE monitoring data from Washington State is misplaced.

The Washington monitoring program was initia ted through rulemaking by Washington state’s Department of Labor and Industries in Decem ber 2003; handler ChE monitoring did not begin until January 2004. EPA completed the carbaryl wo rker risk assessment and IRED decision in 2003 and published the Amended Carbaryl IRED in October 2004. The first draft report of the Washington State Monitoring Program was issued in January 2005. The final report for the first year of the Washington Department of Labor and Industries Medical Monitoring program was

released in March 2005.

Specifically, starting in January 2004, Washington state required that employers offer medical monitoring of baseline and period ic red blood cell and plasma ChE levels for all handlers working with toxicity category I or II organophosphate and/or carbamate pesticides for 50 hours or more in a consecutive 30-day time period. Red blood cell and serum ChE levels of handlers meeting the aforementioned exposure criteria were monitored. The program did not then, and does not now, require monitoring of handlers that handle only NMC pesticides such as carbaryl because these compounds cause only temporary, revers ible ChE inhibition that is not likely to be detected with monitoring. From the beginni ng of the program, handler participation in monitoring was voluntary.

In January 2005, the program criteria were ch anged to require that growers offer ChE monitoring for pesticide handlers exposed for 30 or more hours in a consecutive 30-day period. If handlers chose to be monitored, handlers show ing a 20% depression of ChE levels triggered a workplace audit; those showing a 30% depression in ChE levels were removed from work that could cause further exposure unt il their ChE levels returned to within normal limits. These criteria remain the same today. 18 The workplace audit requires the employer to evaluate their worker protection program and employee pestic ide handling practices, and to document this

audit and all measures to redu ce potential pesticide exposure. A January 10, 2008 directive from the Washington Department of Labor and Industrie s states that in cases where ChE depression > 20% occurs, an employer’s failure to evalua te his worker protection program and correct potential sources of pesticide exposure is co nsidered to be a violation of the rule. 19

The Washington State program was designed to id entify overexposure to pesticides prior to the

onset of illness so that interven tions could be taken to prevent further pesticide exposure that could result in illness. The program also monitors the efficacy of an employer’s pesticide safety and worker protection programs. The program was not designed to provide data for use in quantitative worker risk assessments, such as those conducted by EPA’s Office of Pesticide

18 See the document, Washington State Department of Labor and Industries 2007. Cholinesterase Monitoring of Pesticide Handlers in Agriculture: 2007 Final Report (December 24, 2007).

19 http://www.lni.wa.gov/Safety/Rul es/Policies/PDFs/WRD3327.pdf

- 12 -Programs. For EPA to use the Washington progra m data in risk assessment, the program would need to monitor handlers exposed to carbaryl al one, with monitoring conducted on a daily or hourly basis. In addition, ev aluation of ChE levels from a control group, who followed all pesticide handling and worker protection measures correctly, would be needed. In sum, although EPA reviewed data from the Washington state monitoring program, these data do not provide information on pesticide handlers exposed to carb aryl alone, and are therefore of limited utility for purposes of a rigorous, quantitative occupation al risk assessment.

The Agency continues to monitor the results of the Washington program, which show that the percentage of handlers showing 20% or more depression of ChE declined from 2004 to 2006, following education and outreach. Although a simila r decline was not observed in the reported data for 2007, a change to the program has b een identified that impacted the outcome. Specifically, laboratory services were transfer red from the Washington State Public Health Laboratory (PHL) to the Pathology Associates Medical Laboratories (PAML). A review of test and quality control data indica ted that red blood cell ChE testi ng by the new lab was less precise than that achieved by PHL, which affects the accuracy of test results. Taking this test variability into account, it is likely that the number of over-exposures remained at the same level or declined in 2007 compared to prior years.

3. Agricultural Re-Entry Task Force (ARTF) data

NRDC expressed concern about EPA use of a methodology for establishing a transfer coefficient and estimating field worker exposure to pesticides developed by the ARTF, a task force comprised of pesticide registrants. NR DC criticizes EPA for using the ARTF methodology in setting REIs for field workers because neither the ARTF protocols nor the data have been fully reviewed by the EPA’s FIFRA SAP. NRDC also expressed concern that the sampling methodology employed in the ARTF studies wo uld underestimate worker exposure.

The issues NRDC raises with respect to EP A’s use of data from the ARTF have been addressed in a number of different forums, incl uding a joint letter to Farmworker Justice and NRDC dated July 7, 2007 and a more recent lette r to Farmworker Justice dated January 10, 2008 (“Farmworker Justice Letter”). Since NRDC’s Pe tition was filed, EPA has also presented issues

related to use of the ARTF data to two exte rnal peer review groups : the FIFRA SAP and the

Human Studies Review Bo ard (HSRB). It should also be noted that the monitoring methods used have been included in the Agency’s guide lines for conducting exposure monitoring studies

since the 1980s and that the method used to calculate risk estimate s used in the determination of REIs was also described in those original guidelines.

In summary, the studies sponsored by ARTF have been conducted in accordance with the

established Office of Prevention Pesticides and Toxic Substances (OPPTS) guidelines for Worker Post-application Exposur e Studies and in accordance with good laboratory practice. See 40 C.F.R. § 160. EPA conducted joint reviews of pr otocols used in the ARTF studies with two other independent regulatory ag encies: California’s Department of Pesticide Regulation and Health Canada’s Pesticide Management Regul atory Agency. EPA has reviewed the study reports submitted by the ARTF before using the information in new risk assessments. These

reviews have led EPA to concl ude that the studies were cond ucted in a scie ntifically sound manner and the resulting data were valid. Theref ore, EPA has concluded that the estimates of

the transfer coefficients and re sidue dissipation curves using ARTF data were appropriate for the

- 13 -use in the carbaryl assessment supporting the Ca rbaryl IRED and in th e 2007 revised carbaryl occupational risk assessment.

Although NRDC asserts that the methodology chosen by the ARTF to collect residue samples underestimates exposure, NRDC has not provided a ny information in its Pe tition to support this

assertion. This issue was vetted before th e FIFRA SAP in January 2007 and the Agency’s HSRB in various recent meetings including June 2007. This issue is also addressed in the

aforementioned letters to Farmworker Justice an d NRDC. In addition, NRDC asserts that the ARTF categorization of crops a nd tasks leads to underestimation of exposure for the carbaryl risk assessment. Although EPA does not believe it is required to do so befo re using the data in a risk assessment for an individual pesticide, the Agency plans to present the ARTF groupings of crops and tasks to the FIFRA SAP in December 2008.

In connection with its cr iticism of EPA’s use of the ARTF data, NRDC also asserts that EPA has underestimated the duration of worker exposur e, both in terms of hours worked per day and days per year. NRDC asserts that “many” handlers and field worker s “routinely work 10-12 hour days for 6 to 7 days/week.” Petition at 5. NRDC then cites the US Department of Labor’s National Agricultural Worker Survey (NAWS) ( 2000), which reports that 56% of crop workers work 31-50 hours per week and 15% work more than 50 hours per week. NRDC further criticizes EPA’s assumption of 10 days per year for private growers and 30 days per year for commercial farmworkers, asserting that many farm workers are on crews that work 6 days a week

for weeks if not months at time.

Regarding the matter of hours worked, EPA has concluded that the assumed 8 hour duration for a work day is appropriate for estimating seasona l exposures. This value is consistent with the average 40 hour work week for harvesting fruit and nut crops reported in the findings from the

NAWS 2001-2002. It should be noted that the issue of workday duration and its impact on the results of exposure assessment will be a specific element in the charge to the panel at the December 2008 FIFRA SAP meeting.

The Agency disagrees with NRDC that its cu rrent approach to estimating workers’ postapplication exposures underestimates high end exposure levels. When discussing whether to change one of the assumptions or input values used in the algorithm to assess exposure, it is important to consider how such a change would a ffect the overall tendency of the algorithm to overestimate or underestimate exposure. EPA calculates workers’ post-ap plication exposure to pesticides using the assumption that workers wi ll receive exposure for 8 hours per day for many

weeks.

EPA agrees that exposure depends, at least to some extent, on the number of hours a person works and that longer work hours probably leads to more exposure. However, hours worked is only one of several variables EPA considers wh en assessing multi-day, post-application worker exposure. The Agency’s algorithm also uses othe r variables, including the levels of pesticide residues available in sites where people will be working (generally dislodgeable foliar residues (DFR)), amount of contact a worker has with treated foliage while performing various tasks (transfer coefficients, (TCs)), and dermal abso rption factors which are used when comparing worker exposure to doses from oral toxicity studies.

When assessing exposure to agricultural pesticides, EPA relies on DFR dissipation data based on the maximum application rate. This is clearl y an upper bound assumption. To the extent that a grower applies less pesticide to a site than is allowed by the label, or rain occurs between the

- 14 -time of pesticide application and the time a crop is harvested, the actual DFRs encountered by a worker would be lower, and thus the algorithm could oversta te those workers’ potential exposure. Further, EPA assumes that the worker always enters a treated site at the earliest possible opportunity following application, i.e ., at the expiration of any REI. EPA determines the level of dislodgeable residues on that day and uses the value as the input to the exposure algorithm. This too is an upper bound assumption. If a worker enters a treated site one or more days after the REI has expired, the residues to which he or she will be exposed would be expected to be lower (e.g., from degradation, ra in, etc.) than the values used in the exposure algorithm.

In addition, the TCs EPA uses are arithmetic means based on the highest exposure values measured for a worker conducting a certain type of activity, such as harvesting, pruning, or watering. Many of these TCs are based on indivi duals wearing short-sleeved shirts in which exposure to the forearm includes the inner and ou ter cotton dosimeter measurements representing the lower arm. Thus, these values also represent high-end inputs to the ex posure algorithms. If a worker wears clothing or gloves that afford gr eater protection, he or she will receive less exposure than estimated by the e xposure algorithm. The range of activity-specific TCs is also presented in the Science Advisory Counc il for Exposure policy 3.1 on the use of TCs 20 ; the TCs used by EPA consistently fall in the higher end of the reported ranges.

EPA calculates MOEs for re-entry workers usin g the methodology previously described in this document, by comparing estimates of worker exposu re to a NOAEL or point of departure (PoD). If the toxicity studies used to derive dermal MOEs are conducted by the oral route of exposure, estimates of dermal absorption are generally made based on dermal penetration studies in the rat or comparisons of lowest observable adverse effect levels (LOAELs) fr om dermal and oral studies showing similar toxic effects. In th e carbaryl IRED, EPA used a dermal absorption factor. For the revised carbaryl risk assessment, EPA used data from an in vitro comparative dermal penetration study using rat skin and human skin. These data were used to determine the relative dermal absorption for carbaryl in rats an d humans. Details may be found in the June 28, 2007 document, Carbaryl: Review of in vitro Dermal Absorption Study. (See Docket EPA-HQOPP-2007-0941-005).

The Agency’s exposure algorithm makes the additional conservative assumption that, throughout the period over which exposure is bei ng assessed, the worker engages in the same activity at different sites treated with the same pe sticide. In general, to the extent the worker does not perform the same activities or works at s ites treated with differentpesticides, he or she will receive less exposure to the particular pesticide than is assumed in Agency risk assessments. However, with respect to carbary l, recent data indicates that Ch E inhibition is reversible, with recovery in less than 24 hours and, therefore, dail y exposure is independent of the previous day’s exposure. Thus, for the occupational risk assess ment, the daily exposure (short and intermediateterm) to carbaryl is the ma in duration of concern.

In summary, since most of the assumptions and data inputs used in th e exposure algorithm are either upper bound or high-end, EPA has concluded th at the resulting estimates tend to overstate the potential exposure received by many workers. Fu rther, EPA believes it is relatively unlikely

20 US EPA. 2000. Science Advisory Council for Exposure, Policy 3.1 – Agricultural Transfer Coefficients. August 7, 2000. This policy is periodically updated and is cu rrently scheduled for review at the FIFRA SAP in December 2-5, 2008.

- 15 -that there are many workers whos e actual activities co rrespond to the cond itions reflected in exposure estimates being generated by EPA, such as:

• working continuously over exte nded periods (typically from three to 13 weeks) in sites treated with the same pesticide;

• always performing the same type of activity at treated sites;

• always working in sites that have been tr eated with the maximum allowed application

rate;

• every day entering a new treated site on the day that the REI expired; and

• always wearing the clothing associ ated with the highest TCs.

The Agency recognizes that if there are work ers who meet each of th e conditions specified above and who work more than an average of 8 hours per day, thei r actual exposure could potentially exceed that calculated by EPA. However, the Agency believes that such situations are unlikely to exist and theref ore our current methodology does not underestimate exposures to workers, even where the main duration of concern is daily exposure.

B. Ecological assessment

In several places, NRDC points out that for aqua tic and terrestrial wildlife, EPA’s ecological assessment finds that the risk quotients (RQs) for certain uses exceed EPA’s “level of concern” (LOC). Petition at 7-12. NRDC then mistakenly asserts that therefore these uses present an unreasonable risk, requiring further mitigation. Furt hermore, NRDC asserts that EPA’s analysis of carbaryl concentrations in urban drainage systems underestimates exposure because it predates the cancellation of consumer uses for diaz inon and chlorpyrifos. NRDC further contends

that data show that sales of residential carbaryl products increased as diazinon and chlorpyrifos sales declined in advance of their phase-out dates for these uses. NRDC then finds fault with the Agency for not providing an adequate benefits as sessment for the increased use of carbaryl. In addition, with respect to mammals and aquatic in vertebrates, NRDC reque sts that EPA rerun all its exposure models with the mitigation specified in the Carbaryl IRED to ensure the proposed mitigation will adequately reduce estimated enviro nmental concentration (EEC) values and then recalculate RQs. See Petition at 7-12.

EPA used a screening methodology for the carb aryl ecological risk assessment. This methodology is used as a barometer of risk to screen out use patterns that are not of risk concern so that the Agency can focus further attention on use patterns that may be of concern. An RQ exceeding a LOC in and of itself does not necessari ly indicate a risk of concern; rather it indicates a potential area of risk concern. Furt her, it is not always possible for EPA to quantify reduction in potential ecological risk gained through mitigation using the currently available screening-level methodologies. In addition, EPA’ s screening level risk assessment is but one line of evidence considered in the Agency’s carbaryl decision. For example, ecological incident data, which provide information about actual observed effects of carbaryl in the field also can provide valuable information, based on the nature of specific circumstan ces surrounding the data.

- 16 -1. Level-of-Concern (LOC) exceedances

NRDC asserts that throughout the ecological assessment EPA has determined that the RQs exceed the Agency’s LOC with the implication that therefore carbaryl presents unreasonable risks. Petition at 8-10, 16. However, an LO C exceedance in and of its elf does not necessarily

mean that there is an actual risk of concern. Indeed, the LOCs for a screening assessment, as was done for carbaryl, are meant to screen out us es that are not of concern; not to determine definitively whether certain uses of carbaryl actually cause adverse effects on non-target organisms. Cancellation is not the only option av ailable for uses that do not pass the screen; the Agency could refine the risk assessment, apply mitigation, or conclude that the effects are not unreasonably adverse, and take no further action.

a. Estimates of Ecological Risk

As a general matter, after the RQ s are calculated, they are compared to the Agency’s LOC. These RQs are used by EPA to analyze potential ri sk to non-target organisms and the need to consider regulatory action. These levels are used to indicate when a pestic ide use, as directed on the label, has the potential to cause adverse effects on non-target orga nisms. The Agency generally uses RQs to determine potential risk by comparing them to the LOC:

• Acute Effects to Non-target Organisms (acu te RQ > 0.5 for aquatic animals, mammals, birds);

• Acute Effects to Federally-listed Threaten ed/Endangered Species (acute RQ > 0.05 for aquatic animals or 0.1 for mammals and birds);

• Chronic Effects to Non-target Organism s (chronic RQ > 1 for all animals);

• Acute Effects to Non-listed Plant Risk (RQ >1); and

• Acute Effects to Federally-listed Thr eatened/Endangered Plant Risk (RQ>1).

The Agency may determine that notwithstanding the results of its Ti er I screen, further refinements are likely to show th at the actual risk is significantly less than originally predicted, allowing the Agency to make a qualitative determination that the pesticide will not likely cause

unreasonable adverse effects on the environment. This qualitative assessment may be further informed by the extent and nature of ecological incident data and monitoring data. Finally, the Agency may determine that, on balance, the benefits are sufficient to conclude that, notwithstanding LOC exceedances, usage of a pesticide does not cause unreasonable adverse

effects on the environment.

b. Use of Ecological Incident Data

EPA reviews available data on ecological incide nts to provide an additional perspective on potential ecological risks. As noted in the en vironmental fate and ecological risk assessment (USEPA 2004 21 ) written in support of the interim rere gistration eligibility decision and most recently in the endangered species effect dete rmination for the California red-legged frog ( Rana

21 USEPA. 2004. Interim Reregistration Eligibility Decision Document for Carbaryl. http://www.epa.gov/oppsrrd1/REDs/carbaryl_ired.pdf

- 17 -aurora draytonii ) (USEPA 2007 22 ), relatively few of the repor ted incidents on carbaryl could actually be attributed to labeled use of the compound.

The incident data available when the carbary l IRED was completed showed one fish kill, where the total number of fish killed is not spec ified, and one bird kill involving a single bird

that can be attributed to th e registered use of carbaryl. 23 As a frame of reference to aid in the interpretation of the carbaryl incident data, fo r diazinon, 492 incidents were reported in the EIIS (USEPA 2007 24 ), while 399 and 256 incidents were reported for carbofuran (USEPA 2008 25 ) and azinphos-methyl (USEPA 2007 26 ), respectively. Although the absence of incident reports cannot be construed as the absence of incidents, the available data suggest that given the current uses of carbaryl the incident data, although lim ited, provides a line of evidence that risk estimates provided in the screen ing-level assessment are relativ ely conservative. The data on ecological incidents of carbaryl provide an additional perspec tive on the RQ exceedances.

Fish. With respect to ecological in cidents involving fish reported in the EIIS, a total of three fish-kill incidents were reported for carbaryl. Only one of those incidents, report #B0000-501-92, could be credibly associated with a specific carbaryl use, i.e ., to control gypsy moth in New Jersey.

Birds. A total of five incidents involving birds have been reported; however, only two of the five can be clearly attributed to carbaryl and on ly one of those two could be linked to a specific registered use. The remaining incidents appear to have been associated with either intentional poisoning or the co-occurre nce of much more toxic pesticides . In one incident (I012817-001) a single mourning dove ( Zenaida macroura ) was discovered dead; the animal exhibited reduced acetyl ChE activity and had 2.4 mg/kg of carbaryl in its stomach contents. The report suggests

that birdseed around a feeder had become cont aminated after carbaryl was applied to the property owner’s lawn. In a second incident (I000802-001), five blac kbirds were discovered dead. No residue analysis was conducted on the bi rds but carbaryl residues were detected in a dead squirrel found in the vicin ity; acetyl ChE activity was not reduced in the squirrel. While these incidents do not provide subs tantial evidence that carbaryl is impacting birds in the wild, they do suggest uncertainty regard ing the sensitivity of passerine species to carbaryl, compared to birds such as bobwhite quail and mallard duck, for which the Ag ency has laboratory toxicity

studies and associated data.

Mammals . Although the EIIS database reported two possible incidents involving carbaryl exposure to mammals, neither of thes e incidents could be attributed to a specific use of carbaryl. Of the two incidents reported, one (I000802-001) involved a gray squirrel ( Sciurus carolinensis )

22 USEPA. 2007 Risks of Carbaryl Use to the Federally-Listed California Red Legged Frog ( Rana aurora draytonii ) Pesticide Effects Determination. http://www.epa.gov/espp/litstatus/effects/redlegfrog/carbaryl/determination.pdf

. 23 There are however, a number of reported beekill incident s (approximately 41); however, of these, only two are clearly linked to a specific use of car baryl where carbaryl residues have been detected in the dead bees.

24 USEPA 2007. Risks of Diazinon Use to the Federally Listed California Red Legged Frog ( Rana aurora draytonii) Pesticide Effects Determination. http://www.epa.gov/oppfead1/litstatus/effects/redlegfrog/index.html#diazinon

25 USEPA 2008. Scientific Issues Associated with th e Agency’s Proposed Action under FIFRA 6(b) Notice of Intent to Cancel Carbofuran. Presented to the FIFRA Science Advisory Panel meeting held on February 5, 2008. http://www.epa.gov/scipoly/sap/meetings /2008/february/transcript2008-02-05.pdf

. 26 USEPA 2007. Risks of Azinphos-methyl Use to the Federally Listed California Red Legged Frog. http://www.epa.gov/oppfead1/endanger/litstatus/eff ects/redleg-frog/azinphos-methyl/analysis.pdf

- 18 -and a second involved a hairytail mole ( Parascalops breweri ). In neither case was information provided on the use of carbaryl that may have resulted in the deaths of these animals.

Bees . A total of five bee kill incidents related to carbaryl were reported in the EIIS database in March 2003, when the ecological risk assessment supporting the carbaryl IRED 27 was completed and subsequently published for comment. Two of the reports (I005855-001 and B0000-300-03) do not contain any data but rather reflect general concerns expr essed by the American Beekeeper Federation and the Honey Industry Council on the role of pesticides in be e kills. The Honey Industry Council cited the specific use of carbaryl on alfalfa during the day. In North Carolina (incident #I003826-021), a bee mortality was associated with 0.8 ppm carbaryl residues; however, in a second incident (# I003826-009) in North Carolina, b ee mortality was more likely attributed to methyl parathion than carbaryl. Only in one incident (I001611-002) was the use of carbaryl on a specific crop, i.e. , asparagus in Washington, clearl y associated w ith carbaryl

residues in dead bees.

Subsequent to the publication of the 2003 ecological risk asse ssment, EPA received public comments reporting numerous additional bee kill inci dents associated with the use of carbaryl dating back to the 1990s. 28 Commenters included migratory beekeepers with operations in Minnesota and California and beekeeper associations . The majority of these reported incidents occurred in Washington state and may have been associated with a range of carbaryl uses. Additional incidents were reported in Minnesota and were associated with the use of one formulation of carbaryl, Sevin ® XLR, on poplar tree plantations.

The low number of bee kill incidents captured in the EIIS as of March 2003 underscores that the absence of reports should not be construed as the absence of incidents. However, as an insecticide, carbaryl’s high acute toxicity to bees is not unexpect ed. Carbaryl product labels contain bee warning statements . Formulations of carbaryl, e.g ., Sevin ® XLR Plus, have also been developed to reduce the toxicity of the insecticide to beneficial insects. Thus, the fact that carbaryl use has been associated with a number of bee kill in cidents dating back to the 1990s

alone is not inconsistent with th e Agency’s understanding of potential risks. It should be noted, however, that these previously unreported incidents ha ve not undergone internal Agency review to determine the extent to which they could actu ally be attributed to carbaryl. A preliminary

review of the incident data in dicated that other pesticides be sides carbaryl were used in the vicinity and some of these pest icides are considerably more toxic to bees than carbaryl.

2. Ecological Risk Concerns for Carbaryl

As a preliminary matter, EPA disagrees with NRDC’s characterization that the RQs for carbaryl are “extremely elevated” su ch that they “pose an unreasonabl e risk.” Petition at 8. To the contrary, and as discussed in more detail below, the screening-level RQs for carbaryl do not lead to a conclusion that signifi cant effects are expected for aqua tic life and wildlife species and their associated ecosystems. Single and evendouble digit exceedances of LOCs by screeninglevel RQs do not per se pose an unreasonable risk. Rather, such levels indicate a potential risk concern that may warrant further evaluation, taking into considerati on other lines of evidence. In

27 USEPA 2003. Revised EFED Risk Assessment of Carbar yl in Support of the Reregistration Eligibility Decision (RED). March 18, 2003.

28 See Docket EPA-HQ-OPP-2003-0101, items numbered 037, 042, and 043, comments submitted to EPA in June

2003.

- 19 -addition, EPA has assessed the use of carbaryl and determined that in ad dition to specific high benefit uses, carbaryl’s broad spectrum pest cont rol, low cost, benefits to integrated pest management and short pre harvest interval (PH I) provide benefits to agriculture. Thus, in evaluating carbaryl, EPA has taken into account not just the LOC exceedances but also the level of refinement of the assessment, other lines of evidence (for example incident and monitoring data), the economic and social benefits of the use of carbaryl as well as the mitigation set forth in the carbaryl IRED and RED, and determined that the use of carbaryl does not cause unreasonable

adverse effects on the environment.

a. Level of Refinement and Lines of Evidence

Aquatic Organisms . The scenario modeled for the screening assessment for aquatic organisms is conservative, consistent with its intention as a screen for adverse effects that could occur in vulnerable aquatic ecosystems. The modeled water body is a 1-hectare, 2-meter deep pond located directly adjacent to a treated field, which is a surrogate for a subset of vulnerable aquatic ecosystems. The models used simulate the infl ow of runoff water into the pond, but no outflow. As a result, EECs for chronic expos ure reflect degradation of the pesticide, and partitioning to bottom sediment, but not removal of pesticide residues via outflow from the pond. Fish and invertebrates living a further distan ce from treated areas would be exposed to a lesser extent than those living closer to tr eated areas, and many species will not sp end their entire lives in one area within the water body. These assumptions are a r easonable reflection of the nature of exposure for certain vulnerable water bodies, for example stretches of headwater streams near treatment areas. The modeling scenario, however, doe s not simulate downstream changes in

concentrations in such water bodies.

The simulation of carbaryl application in th e screening model is also conservative, representing a subset of vulnerabl e aquatic environments. The 10-hect are field in this scenario is assumed to be completely planted with the tr eated crop, and 100% of the crop is treated with carbaryl. The locations of the modeling scenario s were chosen for each crop to simulate soils with a high vulnerability for surface-water runoff (a nd therefore transport of the pesticide to the pond). These assumptions are reasonable on the s cale of individual fields treated in vulnerable portions of the carbaryl ag ricultural use area, but va riability in both soil t ype and the percentage of a crop treated are introduced at larger scales. While estimate s of percent crop treated are not

available at a scale that can be used quantitatively in calculating RQs, incorporating this concept

would reduce the overall fraction of the vulnerabl e aquatic systems that would be impacted.

Because of these conservative assumptions, th e Agency is confident that the modeling approach can screen out uses that will not pose an unreasonable risk to aquatic organisms. This does not mean, however, that uses which do not pass the screen will pose a risk to aquatic organisms in carbaryl use areas. While some treat ed fields will be adjacent to water bodies as simulated, attenuation of pesticid e residues in the runoff water from fields that are not adjacent to water bodies will reduce exposure to aquati c organisms. In the 2004 IRED the Agency summarized carbaryl monitoring data as an additiona l line of evidence in the risk assessment. That assessment indicated that although carba ryl was the second most widely detected

insecticide in surface water in the U. S. Geol ogical Survey’s (USGS) National Water Quality Assessment (NAWQA) monitoring program, concentrations overall were lower than those estimated in modeling.

- 20 -The Agency re-evaluated available monitori ng data on carbaryl fr om the USGS NAWQA program (from 1999 – 2005) in the aforementione d 2007 California red-legged frog assessment, again comparing concentrations measured with m odel estimates. At a national scale, carbaryl was detected in 28% of samples (4288 of a tota l of 15,534 samples). Furt her analysis of the detections shows that 19 (0.4% of detections) were sufficient to exceed the non-listed aquatic invertebrate LOC ( i.e ., 0.85 μ g/L). This is 0.1% of all sample s collected. These exceedances occurred in a variety of surf ace waters with watersheds classified as: urban (10 of 19), agricultural (7 of 19) and ot her (2 of 19) in Washington, Texas, Virginia, California, Massachusetts, Connecticut, Colorado, Oregon, and Pennsylvania. The maximum measured concentration of carbaryl was 33.5 μ g/L . The overall conclusion was that the higher detection frequency in urban streams (versus agricultural or mixed land uses) was consistent with data

summarized in the 2003 assessment a nd that concentrations detected in urban streams (mostly low concentrations, a few detections in the multiple μ g/L range), were also consistent with

earlier data.

The California red-legged frog assessment also evaluated RQ exceedances based on the California surface water monitoring. Based on that dataset of the 1393 total samples representing all land uses analyzed by gas chromatography-mass spectrometry (GCMS), 0.072 percent (1 sample) contained leve ls of carbaryl sufficient to ex ceed the LOC for acute exposures to aquatic invertebrates (i.e. 0.85 μ g/L); while none of the 99 total samples analyzed by highperformance liquid chromatography (HPLC) contai ned levels sufficient to exceed the LOC for aquatic invertebrates. The concentration of carbaryl in California urban watersheds was sufficient to exceed the LOC for acute exposures to aquatic invertebrates in 0.64 % of samples (1 of 157 samples) analyzed by GCMS. These data represent another line of evidence of risk associated with carbaryl use and confirm th e 2003 assessment that the screening-level risk assessment represents risks for a subset of vulnera ble aquatic ecosystems where carbaryl is used.

Exposure to Terrestrial Organisms . Although the risk assessme nt for terrestrial animals included a consideration of typi cal application rates, a numbe r of conservative assumptions remain in the carbaryl screening-level risk asse ssment. For example, the Agency assumes that 100% of the feed items consumed by terrestrial animals are treated with the pesticide under consideration, at the maximum label rate, maximu m reported rate, and typical use rate for each crop. The terrestrial risk assessment assumes that the modeled species occupy the treated field 100% of the time. Also, spray drift modeling indi cates that birds or mammals living adjacent to the treated field will be exposed to 50% of the ap plied pesticide, with e xposure declining to 1% of the application rate at a di stance of 990 feet for a fine-to-medium spray. Therefore, while terrestrial organisms outside the treated area might be exposed to carbaryl, it would be at levels below those used to calculate the RQs.

b. Effects on Specific Taxa

(i) Birds

With respect to birds, NRDC criticizes the Agency for not fully evaluating the potential for carbaryl to pose an acute risk to birds, despit e incidents where birds were killed by carbaryl.

- 21 -Petition at 8. NRDC thus requests that EPA pe rform this type of asse ssment. NRDC further asserts that continuing to allow gr anular formulations is “likely to lead to harmful exposures to

birds.” Petition at 8. In a ddition, NRDC asserts that studies from the open literature were omitted from the assessment and NRDC requests that these be included.

None of these assertions are a basis for can celing all carbaryl regi strations. Moreover, contrary to NRDC’s assertion, EPA has assessed acu te mortality to birds. Specifically, available toxicity data for carbaryl, ba sed on testing of game birds and waterfowl, shows no acute mortality to birds. In an acu te toxicity study with mallard ducks, no mortality was seen at the highest dose tested, 2000 mg/ kg. Therefore, the acute LD 50 for mallard ducks is > 2000 mg/kg. Additional studies in ring-necked pheasant a nd California quail showed similar results ( i.e. , acute

LD 50 > 2000 mg/kg). In a subacute toxicity study w ith the same species, no effects were seen at 5000 mg/kg, the highest dose test ed; the sub-acute 5 day LD 50 is therefore > 5000 ppm. Similar

results were also seen in Nort hern Bobwhite quail, Japanese qu ail, and ring-necked pheasant (5 day LC 50 was > 5000 ppm for all species tested). Ther efore, because the available toxicity data did not indicate that carbaryl would cause unreasonable adverse effects on birds following acute exposure, the Agency did not cal culate acute avian RQs for carba ryl. If acute RQs had been calculated, the acute RQ would be less than 0.1, and not of concern.

With respect to granular formulations, EPA has noted previously in this response that the 2007 carbaryl RED requires watering in for granular form ulations used on reside ntial turf. This is expected to dissolve the granule and move the pes ticide into the thatch layer of the turf where it is intended to kill insect pests. In dissolvi ng the granule and moving it away from the surface,

the chemical is less accessible to non-target animals and thus le ss likely to result in adverse effects on non-target animals. Since exposure is reduced, risk would also be reduced. Also, the acute oral and subacute dietary avia n toxicity studies for carbaryl ar e just as releva nt to granular formulations as to liquid formulations.

Moreover, EPA did in fact conduct a comprehensiv e review of the availa ble literature on the effects of carbaryl on non- target species. See Revised EFED Risk Assessment of Carbaryl in Support of the Reregistration El igibility Decision (RED) (March 18, 2003). EPA conducted an

additional literature search in both 2006 and 2007 to support two fo rmal consultations with the

U.S. National Marine Fisheries Se rvice and the U.S. Fish and Wildlife Service (the Services) on endangered species, i.e. , Barton Springs salamander 29 and the California red-legged frog 30

. Indeed, in its revised ecological risk assessment, EPA noted that some passerine species such as starlings and red-winged black bi rds may be more sensitive to carbaryl than mallard duck, bobwhite quail and other bird species mentioned above. Id. However, although two studies in the published literature suggest that carbaryl may be moderately toxic to ring necked pheasants and red-winged blackbirds, and highly toxic to starlings, these data are based on simple screening tests, do not meet EPA data quality crit eria, and are therefore no t appropriate for use in risk assessment. In any case, to address pot ential uncertainty, EPA will consider an additional acute avian toxicity study for passerine birds. This study is a new requirement in the 2008 revised data requirements to s upport pesticide registrations (see 40 CFR part 158, as amended),

29 US EPA. 2007. Risks of Carbaryl Use to the Fede rally Listed Endangered Barton Springs Salamander ( Eurycea

sosorum ). http://www.epa.gov/oppfead1/endanger/litsta tus/effects/carbaryl/esa-assessment.pdf

30 US EPA. 2007 Risks of Carbaryl Use to the Federally-Listed California Red Legged Frog ( Rana aurora draytonii ) Pesticide Effects Determination. http://www.epa.gov/espp/litstatus/effects/redlegfrog/carbaryl/determination.pdf

.

- 22 -and the need for this study will be evaluated in the problem formulation and risk assessment scoping for the registration review of carbaryl, scheduled to commence in 2010.

Finally, with respect to incident s involving birds, NRDC has not identified any incidents that

can be attributed to carb aryl that EPA failed to consider such that either EPA would change its assessment or determine that all carbaryl registra tions should be canceled due to avian risks. As noted previously in this documen t and in the Revised EFED Risk Assessment of Carbaryl in Support of the Reregistration Eligibility Decision 31 , there is one incident in the EIIS involving birds related to the residential use of carbaryl. Th is incident resulted in the loss of a single bird. The relative absence of avian incidents supports th e laboratory data indica ting that carbaryl is practically nontoxic to birds on an acute oral and subacute dietary exposure basis.

(ii) Mammals

With respect to mammals, NRDC asserts that EPA must adjust the mitigation so that “mammals are not harmed by carbaryl use” and re run the risk assessment models based upon the mitigation set forth in the IRED. Petition at 8. Neither of these assertions are a basis for canceling all carbaryl registrations. First, FIFRA simply does not require that EPA ensure that non-target mammals “are not harmed.” With resp ect to ecological risks, EPA does not make a “safety” finding. Rather, EPA must determine that the pesticide does not cause unreasonable

adverse effects on the environmen t, taking into account the econom ic, social, and environmental

costs and benefits of the use of the pesticide. Second, request ing that EPA reassess carbaryl using different modeling assumptions is not a ba sis for cancellation. As noted previously, for mammals, none of the incidents repo rted in the EIIS data could be associated with a specific use of carbaryl. These data represen t an additional line of evidence to indicate that carbaryl is not adversely affecting mammals on an acute oral or subacute dietary expos ure basis in spite of conservative modeling scenarios that result in RQ values exceedi ng acute risk LOCs.

(iii) Fish

With respect to fish, NRDC notes that acute a nd chronic RQ values were only exceeded for the

citrus use. Petition at 9. NRDC is also “extremely concerned” w ith the state of EPA’s knowledge of incidents and request that EPA provi de more detail regarding reported incidents. Petition at 9. Again, with respect to fish, NR DC’s petition does not pr ovide a basis upon which to cancel all carbaryl regi strations. Simply noting that the RQ s are above the Agency’s screening LOC for a specific use is not a basis upon which to conclude that all us es of carbaryl cause

unreasonable adverse effects on the environment.

EPA used sensitive toxicity endpoints to evaluate risk as well as char acterizing effects based on species sensitivity distributions for fish a nd invertebrates in the 2003 IRED. Also, in the carbaryl endangered species asse ssment conducted for the California red-legged frog (USEPA 2007) 32 , EPA used an acute toxicity endpoint used for assessing risk to freshwater vertebrates, a

96-hr LC 50 of 250 μ g/L which is roughly two times lower than the lower 95 th percentile for the freshwater vertebrate acute toxicity sensitivity distribut ion (i.e., a 96-hr LC 50 of 472 μ g/L ). The

LC 50 toxicity values in the distribution ranged from 250 μ g/L (highly toxic) to 20,000 μ g/L (slightly toxic). Carbaryl wa s moderately toxic (96-hr LC 50 range: 1,000 – 10,000 μ g/L) to 78%

31 See docket EPA-HQ-OPP-2003-0101.

32 US EPA. 2007 Risks of Carbaryl Use to the Federally-Listed California Red Legged Frog ( Rana aurora draytonii ) Pesticide Effects Determination. http://www.epa.gov/espp/litstatus/effects/redlegfrog/carbaryl/determination.pdf

.

- 23 -of the fish tested. As such, the use of this toxicity estimate of 250 μ g/L results in a conservative assessment of risk, since the data suggest that the majority of aquatic vertebrates will be less sensitive to carbaryl. The range of RQs for fish calculated in th e IRED using the most sensitive

96-hr LC 50 of 250 μ g/L and maximum use rates was 0.09 to 0.61. The range of RQs for the mean of the sensitivity distribution (96-hr LC 50 of 1.28 mg/L) calcula ted with EECs from maximum use rates is 0.02 to 0.12, all of which are below the acute LOC for non-listed species. The range for the least sensitive of the species ca lculated with EECs from maximum use rates is 0.001 to 0.007, all of which are below the acute LOC for listed and non-listed species

Similarly, the fact that incident data are impe rfect and in many cases lacks sufficient detail to be useful in a rigorous risk assessment is not a basis for cancellation. While NRDC has expressed concern regarding the state of EPA’s knowledge of incident data, the ecological risk assessment provides a detailed description of th e carbaryl-associated da ta in the EIIS. As discussed previously in this response, the incide nt data provide some i ndication that relative to carbaryl’s use patterns, the number of reported inci dents is low.

(iv) Aquatic invertebrates

With respect to aquatic invertebrates, NRDC a sserts that the RQ’s are “extremely high,” and requests that EPA rerun its models using as the base assumptions the mitigation set forth in the RED to “assure itself and the public” that th e proposed mitigation is “adequate” to protect aquatic invertebrates. Petition at 9; see also Petition at 16. In so doing, NRDC notes that no aquatic ecosystem can survive without invertebra tes. NRDC also “encourages” EPA to ensure that chronic toxicity data for estuarine/marine invertebrates ar e received and reviewed in a timely

manner and that the results are in corporated into its determinati ons. NRDC also notes that EPA has not established water quality criteria for carbaryl.

Again, with respect to aquatic invertebrates, NRDC’s petition does not provide a basis upon which to cancel all carbaryl registrations. Simply noting that the RQ values exceed the Agency’s screening LOC is not a basis upon which to conclude that all uses of carbaryl cause unreasonable

adverse effects on the environment. As discussed previously in th is response, the screening level modeling scenario used to evaluate risk pr ovides a conservative estimate of exposure representing a subset of vul nerable ecosystems. In addi tion, although analysis of over 15,000 surface water samples from the NAWQA monito ring program indicated that carbaryl was detected fairly frequently in a variety of eco systems, only 0.4% of detections (0.1% of all samples collected) were sufficient to exceed the non-listed aquatic invertebrate LOC ( i.e ., 0.85

μ g/L) for the most sensitive invertebrate c onsidered in the IRED.

Also, while certain invertebrates may be particul arly sensitive, and the RQs are derived using the most sensitive invertebrate in the Agency’s database, the distribution of species sensitivities suggests that the majority of inve rtebrates are considerably less se nsitive to carbaryl. The acute toxicity estimate used for freshwater invertebrates ( Daphnia magna EC 50 of 1.7 μg/L) is at least a factor of 2X more sensitive than the other aquatic invertebrates (total of 9 species representing 7 genera) for which data were available (96-hr EC 50 range: 1.7 - 26 μ g/L). The range of RQs for

invertebrates calculated in the IRED using the most sensitive 96-hr EC 50 of 1.7 μ g/L, and average use rates, was 2 to 23. The range of RQ s for invertebrates calcula ted in the IRED using

the least sensitive 96-hr EC 50 of 26 μ g/L and average use rates is 0.13 to 1.5, with 60% of the RQs below the acute risk LOC fo r non-listed species. Based on the available information, the conservative use of the toxicity e ndpoints for the most sensitive sp ecies appears to be consistent

- 24 -with the relatively low number of reported ecol ogical incidents associated with the use of carbaryl and the low concentrations of carba ryl in surface water detected by the USGS.

The Agency bases its decision not to cancel all carbaryl registrations on the screening-level assessment as informed by other lines of evidence , such as the species sensitivity distribution, an

evaluation of concentrations found in monitoring data, and the benef its of carbaryl. Insecticides

are made to control invertebrates so it is not unexpected that carbaryl is toxic to aquatic invertebrates if there is sufficient exposure in the environment. Howe ver, based upon available toxicity data, the Agency concludes that while there could be effects ( e.g ., mortality) to some aquatic invertebrate species in a subset of vulnerable waterbod ies, not all species would be affected. In addition, existing monitoring data indicate it is unlikely th at concentrations of carbaryl in surface water will be consistently high enough to exceed the LOC for the most sensitive aquatic invertebrate sp ecies. Therefore, EPA has dete rmined that, with respect to aquatic invertebrates, carbaryl will not cause un reasonable adverse effects on the environment. Furthermore, the exposure and effects data de scribed above do not support NRDCs contention that carbaryl use will cause the elimination of entire invertebrate communities as suggested.

Although EPA does not have chronic toxicity data for estuarine/marine invertebrates, the Agency does not believe that carbaryl is likely to present a chronic risk concern because it degrades very rapidly at pH levels found in ma rine and estuarine environments. Nevertheless, EPA will revisit the data needs for carbaryl duri ng the problem formulation and risk assessment scoping process for the carbaryl re gistration review, whic h is scheduled to be initiated in 2010. Finally, the fact that EPA’s Office of Water has not established water quality criteria for carbaryl is not a basis for canceling all carbaryl registrations.

(v) Amphibians

With respect to amphibians, NRDC asserts that EPA did not include an assessment of information in the open literature in its assessmen t of amphibians. Petition at 9. In particular, NRDC references a “recently” av ailable study (Relyea and Mills 2001) on tadpoles and predator cues. The Agency has reviewed the Relyea a nd Mills article referred to by NRDC entitled

" Predator-induced stress makes the pesticide ca rbaryl more deadly to gray treefrog tadpoles (Hyla versicolo r )" published in the February 2001 issue of the Proceedings of the National Academy of Science . The Agency concluded that while the paper indicates that carbaryl was 2 to 4 times more lethal to gray treefrogs in the pr esence of a predator, that conclusion is confounded by the potential effects of water quality on morta lity. In addition, the Ag ency did not concur with the author's contention that their protoc ol is indicative of "m ore realistic ecological conditions" than the Agency’s current battery of acute and chronic toxicity tests; all of these studies are conducted under rigidly controlled laboratory conditions and are not intended to be representative of all of the vari ables that may affect the toxic ity of a compound in the field.

For instance, it is difficult to design a study th at can accurately reflect field conditions and particularly predator-prey rela tionships. Typically, prey demonstrate predator avoidance behavior in the presence of a per ceived threat. In this study, tadpol es were unable to escape their perceived threat; predatory cues, i.e., seeing a predator (visual cu es) may have protracted their response well beyond the chemical cues released following the salamander's consumption of tadpoles. It is questionable wh ether tadpoles would have rema ined in view of a potential predator under more realistic conditions. In refined ecological assessments, the Agency sometimes has mesocosm study data available to assess the risk of pesticides under "field

- 25 -conditions." These studies, while considerab ly more expensive that the Relyea and Mills protocol, may represent the most accurate reflection of controlled field studies. It is interesting to note though that while mesocosm studies may yield LC 50 values similar to laboratory studies, they rarely provide LC 50 values showing enhanced toxicity. Test species within these studies are better able to rely on compensatory mechanism to shield themselves from the toxic effects of

chemicals.

In addition to reviewing the Rely ea and Mills paper, and contrary to the assertions of NRDC, EPA did in fact conduct a comprehensive review of the available litera ture on the effects of carbaryl on non-target species. See Revised EFED Risk Assessment of Carbaryl in Support of the Reregistration Eligibility Decision (RED) (March 18, 2003). EPA conducted an additional

literature search in both 2006 a nd 2007 to support two formal consul tations with the U.S. Fish and Wildlife Service (USFWS) on endangered species, i.e. , Barton Springs salamander 33 and the California red-legged frog. 34 These assessments relied on fish as surrogates for aquatic phase amphibians. As discussed in these assessments, th e fish toxicity estimate used to evaluate risks to amphibians was the most sensitive toxicity e ndpoint available. Consideration of the mean toxicity value from the species sensitivity dist ribution results in a range of RQs (at maximum application rates) below the acu te risk LOC for non-listed fish, and below the acute risk to endangered species LOC for some fish included in that distribution. As noted in the more refined assessment for the California red-legged fr og, none of the amphibian toxicity data were considered sufficiently robust to use quantitat ively for risk assessment purposes; however, the

available data indicate that bot h aquatic-phase and terrestrial- phase amphibians are orders of magnitude less sensitive to carbaryl than fish.

Nevertheless, whether or not the Agency cons idered information available in the open literature with respect to amphibians, which in th is case it has, is not a basis for canceling all carbaryl registrations.

(vi) Bees

With respect to bees, NRDC “recommends” that EPA review its bee caution statement to determine if it can be improved to “match the inte nt of the law and protec t pollinators.” Petition at 7-8. Specifically, NRDC recommends that EPA modify the second sentence of the label caution to prohibit application to blooming crops or weeds. In addition, NRDC “requests” that EPA require data on chronic exposure to bees and that EPA provide documentation that its mitigation proposals are adequate. Finally, NR DC requests that EPA provide more detail regarding reported incidents, including whether label inst ructions were followed.

EPA agrees that pollinators provide an essentia l ecological function in both agriculture and wildlife ecosystems. However, merely because carba ryl is highly toxic to bees is not a basis for canceling all carbaryl registrations. Similarl y, recommending that EPA impose certain label instructions is again not in and of itself a basis for canceli ng all carbaryl registrations. Nevertheless, EPA is evaluating al ternative language to protect pol linators and bees in particular while balancing the benefits of carbaryl to agri cultural industries such as apple growers (who

33 US EPA. 2007. Risks of Carbaryl Use to the Fede rally Listed Endangered Barton Springs Salamander ( Eurycea

sosorum ). http://www.epa.gov/oppfead1/endanger/litsta tus/effects/carbaryl/esa-assessment.pdf

34 US EPA. 2007

. Risks of Carbaryl Use to the Federa lly-Listed California Red Legged Frog ( Rana aurora draytonii ) Pesticide Effects Determination. http://www.epa.gov/espp/litstatus/effects/redlegfrog/carbaryl/determination.pdf

.

- 26 -depend on carbaryl for thinning fruit early in th e season). EPA has conc luded that appropriate label instructions allow carbaryl to continue to be used without cau sing unreasonable adverse

effects on bees.

Specifically, EPA will be requiring updated enviro nmental hazard statements for most carbaryl product labels, such as the following:

• “This product is highly toxic to bees exposed to direct treat ment or residues on crops or weeds in bloom;”

• “Do not apply this product to targ et crops or weeds in bloom;”

• “Limiting application to times wh en bees are least active, e.g., within 2 hours of sunrise or sunset, will minimize risk to bees;” and

• “Notifying beekeepers within 1 mile of treatment area at le ast 48 hours before product is applied will allow them to take additi onal steps to protect their bees.”

In addition, EPA will be requiring additional pr ecautions under the directions for use of carbaryl on specific crops. Furthermore, carba ryl dust formulations, shown to be the most hazardous to bees, will no longer be used in agriculture (73 Fed. Reg. 49,184 (August 20, 2008)).

The carbaryl bee labeling will vary by formulation type because the data on pesticide toxicity to honeybees indicate that formul ation type is a significant predic tor of a pesticide’s potential

hazard to bees. 35 The Agency has concluded that this revised labeling provides sufficient protection of pollinators. Although EPA considered additional measures, such as mandatory notification of beekeepers before carbaryl app lication and prohibition of carbaryl application during certain times of day, whic h could theoretically further pr otect pollinators, the Agency

does not consider these to be feasible on a natio nal basis and therefore is not requiring these measures on carbaryl labels at this time. Ma ny states do not register bee hives nor have a notification system in place, so notification would be impossible b ecause the location of hives is not known. Nonetheless, the revised carbaryl labe ling will also contain advisory language, such as the examples given above, re garding notification and application timing. In addition, EPA

continues to work with the North AmericanPollinator Protecti on Campaign (NAPPC) on protecting pollinators from potential adverse effects of pesticides.

As mentioned previously, EPA disagrees with the underlying pr emise behind NRDC’s request for documentation with respect to the adequacy of the bee label statement. Again, EPA disagrees with the implication that before EP A can impose mitigation th e Agency must have empirical evidence that the mitigation will provide a certain, measurable result. To the contrary, EPA can impose mitigation both when there is empirical evidence to support a specific mitigation measure (such as particular PPE) or when, in the Agency’s reasonable judgment, particular mitigation is necessary so that use of the pesticide does not cause unreasonable adverse

effects on the environment.

35 Johansen, Carl. 1977. Pesticides and Pollinators. Chapter in Annual Review of Entomology

. Vol 22, p.177-192. Palo Alto, CA: Annual Reviews Inc. Morse, Rodger A. 1997. Honey Bees and Pesticides. Appendix 5 in Honey Bee Pests, Pred ators, and Diseases

, Third Edition. RA Morse and K Flottum (eds). Medina, OH: The AI Root Company.

- 27 -With respect to chronic bee data, EPA requi red a field pollinator study (OPPTS Guideline 850.3040) in the March 2005 DCI to examine the poten tial chronic effects of carbaryl on bees. The DCI also required the registrant to submit a protocol to EPA for review and approval prior to initiation of the study. Although the registrant su bmitted the protocol, EPA scientists identified numerous issues in the protocol and these issues were not resolved to the Agency’s satisfaction prior to study initiation. The study was complete d and found to contain nu merous deficiencies. However, because carbaryl is no longer used on hybrid poplar plantations in the state of Minnesota, 36 and because EPA believes th at labeling can address the uncertainties regarding the toxicity of the SevinTM XLR PL US formulation that the stud y would address, EPA is not requiring the study to be repeated.

With respect to the details of incidents related to the use of carbaryl, there are limits to what is available to EPA. Section 6(a )(2) of FIFRA only requires pesticid e product registrants to submit adverse effects information about their produc ts to EPA; however, private citizens and State/local governments are not compelled to report adverse effects from pe sticides. Therefore, the ability of EPA to reflect adverse effects resu lting from the use of pesticides depends to a large extent on the cooperation of the growers an d the general public to submit information that is both useful and timely. When such informa tion is received, it is entered into the EIIS database; unfortunately, the data submitted do not al ways contain enough detail to be useful in a rigorous risk assessment. Other than a bee kill incident associated with the use of carbaryl on asparagus in Washington, none of the other reports on bee kills contain sufficient information to implicate a specific carbaryl product or a specif ic use of carbaryl, ther eby providing a basis for imposing additional label restrictions.

(vii) Endangered species

With respect to the endangered species, NRDC describes the number of scenarios that

exceeded the level of concern as “too numerous to list here” and requests that EPA report RQ values for endangered species. Petition at 13. NRDC then criticizes the Agency for not implementing reasonable and prudent alternat ives developed by the USFWS during a 1989

consultation in which the USFWS concluded that carbaryl use would likel y result in jeopardy for 86 species. NRDC also criticizes the Agency for failing to re-initiate cons ultation. Nonetheless, NRDC is “encouraged” that EPA has been engage d in consultations with the National Marine Fisheries Service (NMFS) as well as “additional consultations with both the USFWS and NMFS.” Petition at 13. NRDC then requests that EPA conduct these consultations and implement the results in a timely manner. In the interim, NRDC requests that EPA implement mitigation measures that will eliminate ha rmful exposures to endangered species.

EPA understands that NRDC is advocating for more stringent mitigation in order to eliminate all potential risk to non-target species, includi ng endangered species. In fact, EPA has initiated formal consultations with the NMFS and USFWS for the California red-legged frog 37 and the Barton Springs salamander 38 in Texas as well as for 26 species of Pacific salmon and steelhead

36 Personal communication (e-mail) from John Peckham, Minnesota Department of Agriculture, to C. Scheltema, EPA, Office of Pesticide Programs, August 13, 2008.

37 EPA’s Effects Determination for the California Red Legged Frog was sent to the US Fish and Wildlife Service in

October 2007.

38 EPA’s Effects Determination for the Barton Springs Salamander was sent to Bryan Arroyo, Acting Assistant Director for Endangered Species, US Fish and Wildlife Service, on September 21, 2007.

- 28 -in the Northwest 39 . Consultation packages for the effects of carbaryl on the California redlegged frog, the Barton Springs salamander and P acific salmon and stee lhead (sent to the services in April, 2003) are availa ble on the EPA website at the URL http://www.epa.gov/espp/

. Once EPA initiates a consultation with the NFWS and the NMFS, the Agency must wait for the Services to respond. EPA has yet to receive responses from the Se rvices for carbaryl. The next step in this collaborative effort is for the Serv ices to issue a Biologica l Opinion stating whether carbaryl use is likely to adversely affect the identified Federally listed, threatened, and/or endangered species, and if so, identifying reas onable and prudent measures/alternatives to

avoid/reduce risks associated with the use of carbaryl. In addi tion, EPA will continue to work with the Services during the registration review of carbaryl, which will include an assessment of potential risks to endangered species throughout the entire carbaryl use area.

c. Sub-lethal effects.

NRDC finds fault with the Agency’s use of lethal concentration for comparison with EECs

because the use of the ac ute toxicity endpoints ( e.g. , LD 50 values for mortality) does not address sub-acute behavioral or physiological effects th at may occur prior to mo rtality and yet can still have significant sub-lethal effects on many species includi ng immune system suppression, hormone disruption, behavior eff ects, mutagenicity, carcinogenicit y, “and others.” Petition at 12. In addition, NRDC asserts that EPA does not s ubstantially address indire ct effects, such as effects on food supply and habitat, or assess the potential for synerg istic or additive effects. Again, NRDC requests that EPA rerun its models with the mitigation set forth in the IRED and to “reduce or eliminate” uses where the pr oposed mitigation does not ensure non-target organisms will be protected.

On the whole, the Agency does not consider th ese comments as providing a basis upon which to cancel all carbaryl registrations. Mortality is the acute endpoint used in ecological risk assessments for birds, mammals and fish for all pest icides, and has been for at least 30 years. In any case, what NRDC fails to take into account is that acute effects are but one aspect of EPA’s ecological risk assessments. Although acute toxicity endpoint s (e.g. mortality) alone may not account for ecological hazards from sub-lethal exposures, EPA uses other data to assess ecological hazards, including sub-lethal effects.

The Agency’s Overview of the Ecological Risk Assessment Process in the Office of Pesticide Programs (2004) document 40 , available at http://www.epa.gov/espp/consultation/ecoriskoverview.pdf , describes the assumptions and limitations regarding sub-lethal effects. For an ecological risk assessment, the screening risk assessment relies on the acute mortality endpoint

as well as a suite of sub-lethal responses to the pesticide, as determined by the testing of a species’ response to chronic exposure conditions and subsequent chronic risk assessment. Examples of these measurement endpoints for birds and mammals include the following:

39 EPA’s Effects Determination for Carbaryl Relative to 26 Pacific Salmon and Steelhead was sent to Don Knowles, Director, Office of Protected Resources, on April 1, 2003.

40 US EPA Office of Pesticide Programs, 2004. Overview of the Ecological Risk Assessment Process in the Office of Pesticide Programs, U.S. Envir onmental Protection Agency: Endangered and Threatened Species Effects Washington, DC. January 23, 2004.

- 29 -Birds: Reproduction Maternal weight Eggs laid/hen Eggs cracked Eggshell thickness Viable embryos Hatchling number 14-day survivors Gross necropsy Observations of other clinical signs

Mammals: Two-Generation Total pa nel of reproduction parameters Reproduction including: Histopathology, parental and offspring growth, weight, mating, lactation, gonadal development milestones, sexual organ performance and offspring production

The ecological effects characterization section of the carbary l ecological risk assessment

describes the results of ecotoxico logy studies conducted to measur e sub-lethal responses to the pesticide. In addition, the assessment of eff ects to aquatic inverteb rates and aquatic and terrestrial plants is undertaken not only to evaluate direct eff ects to the survival growth and reproduction of these taxa, but to qualitatively evaluate them in te rms of providing a forage base

for fish and terrestrial animals.

Finally, EPA disagrees that an a ssessment of the additive eff ects of all chemicals acting though a similar mode of action is necessary. To the contrary, in its screening-level assessment, EPA already assumes that 100% of feed for an organism is treated with carbary l. Consequently, the scenario already assumes that a crop/pest complex that can be tr eated with an NMC is already 100% treated with carbaryl. The Agency does not routinely include, in its screening risk assessments, an evaluation of mixtures of active ingredients, either those mixtures of multiple active ingredients in product formulations or those in the applicator's tank . In the case of the product formulations of active ingredients, each activ e ingredient is subject to an individual risk assessment for regulatory decision regarding the ac tive ingredient on a particular use site. If effects data are available for a formulated produ ct containing more than one active ingredient, they may be used qualitatively or quantitativ ely in accordance with th e Agency’s Overview

Document 41 and the Services’ Evaluation Memorandum. 42

41 Ibid.

42 US Fish and Wildlife Service (USFWS) and US National Marine Fisheries Service (NMFS). 2004. Letter from USFWS/NMFS to U.S. EPA Office of Prevention, Pes ticides, and Toxic Substances. January 26, 2004. ( http://www.fws.gov/endangered/consultations/pesticides/evaluation.pdf ).

- 30 -3. Conclusion on Ecological Ri sks Posed by Carbaryl.

In sum, EPA’s screening level assessment indica tes that carbaryl may present ecological risks of concern based upon RQs that exceed some of the Agency’s LOCs. However, consistent with the purpose of the screening level risk assessmen t, which is to determine use scenarios for a pesticide that do not pose a risk of concern, the parame ters and assumptions for the derivation of carbaryl RQs are conservative. For instance, the RQs for aquatic animals were calculated using an exposure scenario representing a small pond lo cated directly adjacent to a 10-hectare field, which is completely planted with the crop a nd treated with carbaryl. This represents a waterbody that is characteristic of a subset of vulnerable aquatic water bodies in agro-ecosystems nationwide. An analysis of surface-water m onitoring data from the USGS NAWQA monitoring program provides another line of evidence that the RQs above LOCs for aquatic animals represents risks for a subset of vulnerable wa ter bodies where carbary l is used. Although carbaryl was detected in 28% of over 15,000 surface water samples, only 0.1% of all the samples

collected had concentrations sufficient to exceed the non-listed aquatic in vertebrate acute LOC. The toxicity data available in the risk assessmen ts for carbaryl provide another line of evidence with which to evaluate the potenti al severity of risk to aquatic animals. The RQs were calculated using the most sensitive species in the species sensitivity distribution for each taxon. However, the acute toxicity endpoint for all fish species fo r which EPA has data spans almost two orders of magnitude. RQs for fish calculated with the mean toxicity value from th e distribution would be

below the non-listed acute risk LOC for fish. Similarly, the range of acute toxicity endpoint values for invertebrates spans more than an orde r-of-magnitude. Therefore, exposure in a water body that would lead to an exceedance of an LOC would not necessarily cau se the same level of adverse effects throughout the assemblage of species in a water body.

The screening-level risk assessment indicated the potential for risk to terrestrial mammals and

invertebrates. Acute risks to birds were below the Agency’s LO C. However, the Agency also

considered other lines of eviden ce in considering the risk to ma mmals, such as available adverse

incident data. The number of incidents associated with carbaryl is low. Although the absence of incident reports cannot be construe d as the absence of incidents, the available data suggest that current uses of carbaryl do not adversely affect non-target organisms. The incident data, although limited in its ability to quantify potential risks, pr ovides a line of evidence that risk estimates provided in the screen ing-level assessment are relativ ely conservative. The data on ecological incidents of carbaryl thus provide an additional perspective on the RQ exceedances.

Therefore, given the purpose and inherent conser vatisms in the screening-level risk assessment approach combined with the cont ext provided by additional lines of evidence related to the risks presented by carbaryl to non-listed species, EPA is satisfied that it can qualitatively determine that the risks posed by carbaryl to non-listed species are limited to certain taxa affecting a limited number of species in a subset of vulnerable environments.

Nonetheless, EPA recognizes that for threatened and endangered species specific temporal and spatial refinements are often necessary to fullyevaluate the risk pr esented by a particular pesticide. EPA has initiated formal consultation with the Services for several species and will continue to assess risk to endangered species nationwide during the registration review of carbaryl, which is scheduled to begin in 2010.

- 31 -4. Estimating Carbaryl Risk Based on Mitigation Measures

NRDC repeatedly requests that EPA “rerun” th e risk estimates based on the mitigation set forth in the RED through its ecological modeling s cenarios. Petition at 8-12 and 16. In so doing, NRDC questions the adequacy of proposed mitigation measures, asserting that EPA has provided no calculations or evidence that would support it s assumption that the proposed mitigation will reduce ecological risks below the screening LOC.

First, simply asserting that the proposed mitigat ion may not be adequate and further mitigation may be required is not a basis for canceling all ca rbaryl registrations. Furthermore, FIFRA does not require EPA to quantify or elim inate all uncertainties in it scie ntific assessments. As long as the estimates and assumptions EPA uses to bound its assessments are reasonable, EPA can fulfill its statutory mandate and concl ude, based upon a qualitative assessm ent, that a pesticide does not

cause unreasonable adverse effects on the environment.

In addition, EPA disagrees with the implication that before EPA can impose mitigation the Agency must have empirical evidence that th e mitigation will provide a certain, measurable result. To the contrary, EPA can impose mitigation both when there is empirical evidence to support a specific mitigation measure (such as particular PPE) or when, in the Agency’s reasonable judgment, particular mitigation is necessa ry so that use of the pesticide does not cause

unreasonable adverse effects on the environment. Thus, EPA disagrees with the underlying premise behind NRDC’s request for quantitative documentation with respect to mitigation.

EPA did evaluate the effects of some mitigati on on risk estimates, by evaluating a range of application rates at and below maxi mum label rates. However, as described below, the effects of some mitigation measures imposed for carbaryl can only be characterized qualitatively, and

cannot be reflected in th e calculation of RQs. For example, possible increases in the use of carbaryl, which are anticipated by the NRDC as discussed below, would not be reflected in the RQs calculated for terrestrial or aquatic animals in the ecological risk assessment, because the Agency already assumes that 100% of the feed ite ms consumed by terrestrial animals are treated with the pesticide under consid eration. The amount of residue on each potential food item for terrestrial animals was also calculated using th e maximum residues identified in the published literature (Hoeger and Kennaga 1972; Fletcher et al 1994) 43 which serves as the basis for the terrestrial exposure model. Similarly, for the aq uatic risk assessment, the watershed in each scenario is assumed to be fully planted with the crop simulated, with 100 % of that crop treated with the pesticide. Therefore, because the actual percent crop treated is not considered, increases in use will still not result in an exposure scenario expected to exceed that used for the ecological screening risk assessment.

In addition, maximum application rates were redu ced for mosquito control, citrus, asparagus, and sunflowers in the IRED. Reduction in app lication rates is directly reflected in RQ

43 Hoerger, F., and E.E. Kenaga. 1972. Pesticide residues on plants: Correlation of representative data as a basis for estimation of their magnitude in the environment. In F. Coulston and F. Korte, ed

., Environmental Quality and Safety: Chemistry, Toxicology, and Technology , George Thieme Publ,. Stuttgart, West Germany, pp. 9-28.

Fletcher, J.S., J.E. Nellessen, and T.G. Pfleeger. 1994. Literature review and evaluation of the EPA food-chain (Kenaga) nomogram, and instrument for estimating pesticide residues on plants. Environmental Toxicology and Chemistry 13 (9):1383-1391.

- 32 -reductions, as indicated in the risk assessment. Furthermore, aerial applic ations were prohibited for certain formulations applied to corn (field, pop, and sweet), grain sor ghum, alfalfa, rice, and

sunflowers. 44 Prohibiting such aerial a pplications reduces the spra y drift exposure assumed in the calculation of RQs for the aq uatic assessment from 5% to 1% of applied carbaryl, which are the default assumptions for aerial and ground appl ications, respectively. Prohibition of aerial applications also decreases the distance from a tr eated field that foraging terrestrial animals may be exposed to carbaryl, and reduces the amount of carbaryl to which an imals near the treated field will be exposed. However, as described above, the terrestrial exposure scenario used in screening assessments assumes that birds and mammals occupy and feed in the treated field 100% of the time. Therefore, while reductions in the maximum application rate for some crops would be reflected in the resp ective RQs for those crops, risk reduction resulting from reductions in spray drift to areas away from the treated field would not be reflected in the RQs.

The following are mitigation measures implemente d to address carbaryl risks that cannot be modeled using existing tools, but that would reduce the overall mass of pesticide put into the

environment:

• Subsequent to the publica tion of the Carbaryl IRED , EPA canceled broadcast application of liquid carbaryl formulations to residential lawns. This mitigation is expected to reduce the amount of carbaryl available for runo ff to surface water in urban

and suburban areas.

• A number of carbaryl uses have been can celed, including all pet uses (except pet collars), all direct uses on poultry an d in poultry houses, and all use on wheat. Subsequent to the carbaryl RED, Bayer has requested cancellation of all use on millet, all use on succulent (fresh) peas and beans, and most use of granul ar formulations on leafy vegetables (except Brassica). 45 Another carbaryl produ ct registrant, Drexel Chemical company, has requested cancellation of carbaryl dust formulations used in agriculture.

• In the 2007 Carbaryl RED, EPA required th at all carbaryl granular products used on

residential turf be watered in. This is expected to reduce the number of granules on the soil surface that could be eaten by visiting bi rds or mammals. In addition, watering in granules will reduce the amount of carbaryl that can be transported to surface water by

runoff and erosion.

• Bayer’s voluntary cancellation of all ultra lo w volume (ULV) applications of carbaryl used as a mosquito adulticide and cancellati on of all use of dusts in agriculture is expected to reduce risks to honeybees, a lthough this can not be quantified through

EPA’s models. 46

The mitigation and voluntary cancellations desc ribed above are expected to reduce but not eliminate all ecological risks; however, FIFRA doe s not require that all risks be eliminated.

44 Wettable powder and granular formulations may no longer be applied by air, with the exception of pelleted carbaryl bait used in federal and state Grasshopper and Mormon cricket suppression programs.

45 EPA published a notice of receipt of request to amend car baryl registrations under FIFRA § 6(f) in the Federal Register on August 20, 2008.

46 Dusts are the most hazardous formul ation to honeybees because of greater exposure potential; therefore, the elimination of carbaryl dust in agriculture is expected to benefit bees. Prohibiting aerial applications will also reduce hazard to bees because aerial ap plication is association with greater drift than ground application.

- 33 -FIFRA does, however, require EPA to also take into account the economic, social, and

environmental costs and benefits of the use of any pesticide when making a reregistration eligibility decision or a decision to cancel uses . Finally, NRDC criticizes the Agency for not implementing mitigation solely to mitigate ecologi cal risks. EPA believes that there is nothing inappropriate about mitigation that is designed to address more th an one risk factor, such as reduced application rates that re duce both worker exposure and ecologi cal risks. To the contrary, mitigation that addresses more than one risk factor is eminently reasonable.

C. Benefits of Carbaryl

NRDC asserts that carbaryl use exceeds the Agen cy’s LOCs with respect to ecological risks.

NRDC further asserts that EPA has not provided adequate docume ntation demonstrating that the benefits of carbaryl exceed the identified ecol ogical and worker risks. Petition at 14. In addition, NRDC asserts that for some uses of carbaryl there ar e alternatives.

Generally, pesticides used in residential se ttings provide benefits interms of reducing pests that cause or carry disease, cause damage, are poisonous, or are nuisances. Similarly, pesticides used in commercial settings benefit people by controlling pests that may cause damage or interfere with manufacturing proc esses or result in adulterated products. The benefits of an agricultural pesticide are essentially the im provements in the production of food and fiber resulting from the pesticide use. Improvement s in production can occur because the pesticide reduces damage caused by insects, weeds or plant pathogens, leading to an increase in output or improvement in the quality of the commodity. Use of a chemical pesticide may also reduce costs of production compared to alternativ e pest control measures. These benefits largely accrue to the users of the pesticide, i.e. , farmers, in the form of higher in comes. Consumers may also benefit because higher production and/or lower costs tran slate into a cheaper and more abundant supply

of food or fiber.

Typically, improvements due to a pesticide are m easured against the next best available pest control alternative, which may be chemical, bi ological, or mechanical. Benefits may differ between sites, depending on the particular pest s causing damage or th e available alternative control measures. Benefits may also differ within sites because crop production systems differ across agro-climatic zones. Pest problems may be specific to certain regions and alternatives may not be appropriate in all situations.

As part of the reregistration process, including the IRED and RED, EPA examined the use of carbaryl on more than 30 agricultu ral and non-agricultural sites to evaluate the benefits carbaryl provides 47 . Carbaryl is more efficacious for control of some pests. In addition, less quantifiable benefits of carbaryl arise from several ch aracteristics of the chemical, the regulatory environment, and economic factors. First, carb aryl is a broad-spectrum insecticide that may provide control over multiple pests with a single application. The multi-pest control achieved with a broad spectrum insecticide can result in fewer overall insecticide applications and lower

47 The Agency completed a number of assessments investigating the use and/or benefits of carbaryl across a wide range of use sites in support of reregistration.

- 34 -costs. These benefits are ofte n difficult to quantify as damage from secondary insects may not be noted until pest control practices cha nge and secondary pests are manifested.

Second, carbaryl can provide an alternative mo de of action, which can be important in managing the development of insect resistance to other pesticides. Carbaryl can be used in rotation with other insecticides, helping to mainta in the effectiveness of alternative insecticides, particularly in situations where few alternative insecticides are av ailable or alternatives belong to a single insecticide class.

Third, carbaryl has a relatively short PHI and RE I, giving growers greater flexibility in timing applications and other field activi ties. Avoiding pest damage can be particularly critical in the period immediately prior to the harvest of fr uits and vegetables to produce a marketable commodity. Reliance on insec ticides with long PHIs tends to encourage more prophylactic treatments, which is counter to integrated pe st management (IPM) programs that promote delaying pesticide treatments until pe st populations reach damaging levels.

Finally, carbaryl is often less expensive than ot her treatment options. Agriculture is highly competitive and producers have little or no opport unity to “brand” their products and influence the prices they receive. Keeping costs low can be the only means of staying competitive with producers in other regions, including other countries.

All these characteristics are not important in all situations. As noted above, the magnitude of benefits can be crop and location specific. The re st of this section describes the benefits of carbaryl in a variety of crops that EPA concl udes is representative of the benefits across agricultural uses.

The proportion of the crop treated with a pesticide is often a good indication of its importance to production. For example, approximately 35- 40% of acreage cultivated in apples and asparagus are treated each year with carbaryl, su ggesting a relatively high value to producers of those crops. Carbaryl plays a dual role in apple production: in sect control and fruit thinning 48

. No single alternative is available for both tasks. As a fruit thinning agent, carbaryl reduces the post-bloom number of fruit, allowing production of larger, more marketable fruit. Other chemical thinning agents can be severely impact ed by environmental temperature (before, during and after application), tree vigor, fr uit variety and need for precise timing of application. Poorly timed fruit thinning can throw a tree into a bienni al production cycle, with a low production year followed by a high production year. In high produ ction years, average fruit size tend to be smaller (resulting in lower $/lb re turns), while in low production year s, average fruit size tends to be larger. Excessively large fruit also yields lower returns. Hand thinning is generally prohibitively expensive except for specialty and organic apples fo r which growers receive higher prices. Carbaryl also provides superior control of white apple l eafhopper. This insect may cause spots on the fruit with its excrement, which affect s quality and reduces the price growers receive. The leafhopper may also pose a work place hazard during harvest. Carbaryl has the shortest PHI of all insecticide alternatives, allowing more flexibility for growers who can wait to see if

48 US EPA Office of Pesticide Programs. 2007. Alterna tives Assessment for Carbaryl Use on Apples. May 10,

2007.

- 35 -leafhopper populations reach damaging levels befo re treating. Reliance on insecticides with longer PHI’s could result in pr ophylactic applications which c ould very well be unnecessary.

The short PHI is also critical for asparagus growers 49 , who harvest spears at short intervals. Alternatives to carbaryl have l onger PHI’s or are limited to a si ngle application per year. The target pest, the asparagus beetle, deposits eggs on the spears making them unmarketable and potentially leading to the loss of all production. The se verity of potential da mage in combination with a high percent of the crop subj ect to pest infestation implies that much of the benefits of carbaryl accrue to consumers, who would otherw ise face higher prices resulting from a limited supply of asparagus.

Sweet and tart cherries are al so quite reliant on carbaryl, with about 30% of sweet cherry acreage and 10% of tart cherry acreage treated annually. 50 The main target pest is the cherry fruit fly, but there are numerous secondary pests that an application of carbaryl can simultaneously control. The cherry fruit fly is one of the most critical insect pests in cherry production; buyers sample for it cons tantly and a single pest can lead to the rejection of an entire shipment of produce. Organophospha te insecticides lik e azinphos-methyl have been the primary means of control, but there ha s been a major emphasis by EPA a nd the industry to either phase

out or reduce their use. Carb aryl has long been a ‘back up’ tr eatment to maintain continuous protection during the relatively l ong intervals required between organophosphate applications. Carbaryl is also valuable as a ro tational spray to maintain the effectiveness of other alternatives, such as spinosad.

Carbaryl also provides substantia l benefits in crops with relati vely low percent treatment such as citrus, where about 5% of the crop is treated. 51 Carbaryl is used on ci trus to control of the root weevil, a pest that is curren tly limited in area but highly da maging as it can lead to the death

of trees. The loss of trees has a substantial impact not only on current income, but also on future income of a grower since severa l years of production can be lost before a newly planted tree begins to produce fruit. Given intense competition from foreign production, especially of oranges, even small impacts can affect the viab ility of a citrus grove . Carbaryl is a key component of citrus weevil eradication programs wh ich target all stages of weevil developmental (egg, larva, and adult). Carbaryl is the most efficacious insectic ide targeting the adult stage of the weevil and prevents its dispersion to non-infe sted areas. Synthetic py rethroids would be the likely alternative to carbaryl for adult weevil control. While wide ly used in citrus, pyrethroids typically target other pest s, not the root weevil.

The benefits of carbaryl in several other tree crops are more variable. 52 There is relatively high use in pecans and pistachios (10-20% crop treated) and somewhat lower in olives (5-10%). There are few registered alternatives for olives an d pistachios, but the targ et pests are sporadic.

49 US EPA Office of Pesticide Programs. 2003. Summary Tables of Carbaryl Benefits Information on Selected Crops. May 23, 2003.

50 Ibid.

51 US EPA Office of Pesticide Programs. 2007. Alternatives Assessment for Carbaryl Use on Citrus. June 6, 2007; and US EPA Office of Pesticide Programs. 2003. Benefits Assessment for Carbaryl Use on Citrus: Impact of Extending the Re-entry Interval (REI). June 12, 2003.

52 US EPA Office of Pesticide Programs. 2003. Summary Tables of Carbaryl Benefits Information on Selected Crops. May 23, 2003.

- 36 -Alternatives in pecans are pr imarily organophosphates and synthe tic pyrethroids and carbaryl offers a unique mode of action to guard agai nst resistance developing, particularly to the pyrethroids. Very little carbaryl is used in almond 53 and walnut production. In almond production, carbaryl is considered a good dormant season treatment for scale when there is resistance to organophosphates. Sy nthetic pyrethroids ar e also an option. However, carbaryl is not widely used due to its t oxicity to bees, upon which almond producers are very dependent for pollination services.

EPA acknowledges that there are situations wher e the quantifiable bene fits of carbaryl are low. In field corn, 54 carbaryl is one of a number of pesticid es available for control of adult corn rootworm, cutworm, flea beetle, grasshopper, and Japanese beetle, all of which appear to be rather sporadic pests. The main advantage of carbaryl may be lower treatment costs, which can increase a grower’s net operating revenue around 2-5%. Net operating revenue is a measure of a farmer’s income, although it does not consider fi xed production costs. Recent increases in the price of corn, however, would reduce the advant age in comparison to grower income, although increasing fuel costs may offset such gains.

Carbaryl is also used on a sm all proportion of carrot acreage, 55 primarily for the control of the aster leafhopper, which is a di sease vector. The alternatives include an organophosphate and a synthetic pyrethroid; according to IPM programs, the latter loses effectiveness in hot weather. Thus, under certain conditions, carbaryl may be the be tter alternative. It also provides another mode of action to help avoid resistance developi ng. In California, the major producer of fresh carrots, carbaryl appears to have a cost advant age. It is also wort h noting that synthetic pyrethroids are Restricted Use Pesticides, which could limit their availability to small producers, while carbaryl is restricted onl y in California. According to the 2002 Census of Agriculture,

80% of carrot farms are less than 100 acres, but these small produ cers account for less than 4% of the carrot acreage.

As another indication of the importance of carbaryl in the diverse production systems in which it is currently available, EPA received a large number of public comments indicating support of the continued registration of carbaryl followi ng publication of NRDC’s petition to cancel registrations of carbaryl. All comm ents can be found in the docket at www.regulations.gov in docket number EPA-HQ-OPP-2005-0077. A brief summary of the comments follows; reference to specific comments are annotated by their document ID number.

Comments were received from university exte nsion personnel (Rutge rs University (0004), Michigan State University (0055), University of Hawai'i (0059), and Virginia Technical University (0061)); grower associations (US Apple Association (0058) and the Northwest Horticultural Council (0063 )); and private growers (0006, 0035, 0039, 0040, 0046, 0047, and 0053) indicating the importance of carbaryl in crop production. The crops covered include

53 US EPA Office of Pesticide Programs, 2008. Assessment of the Benefits of Carbaryl on Almonds. September 29,

2008.

54 US EPA Office of Pesticide Programs. 2008. Benefits of Carbaryl to Producers of Field Corn. September 30,

2008.

55 US EPA Office of Pesticide Programs. 2008. Impact As sessment for the Use of Carbaryl on Carrots. September 26, 2008.

- 37 -apple, blueberry, grape, peach, plum, sweet potato, and other minor crops. Bayer (0062) also submitted information about the use and importa nce of carbaryl in citrus production and for insect control in turf. Some comments provide d information about pests controlled by carbaryl,

discussed various alternatives to carbaryl, and described the disa dvantages of these alternatives. Commenters stated that carbaryl is an importa nt part of their IPM programs and provides an alternative to the use of organophosphates and s ynthetic pyrethroids. Carbaryl provides longlasting control of a wide range of pests and multiple chemicals applied multiple times would be necessary to replace carbaryl. Commenters also indicated that the retail produce market is very sensitive to insect damage a nd the possibility of insects in their produce. Apple growers discussed the importance of carbary l as a thinning agent, indicating that other chemicals were

sensitive to time and environmental conditions an d their application could result in severe over thinning if temperatures increased following an application. Most comme nters indicated that hand thinning would be the only viable option if use of carbaryl is not permitted. Several private growers mentioned that small operations are es pecially impacted by pesticide regulations.

EPA also had a public comment period followi ng the release of the IRED in 2004. These

comments can be found at www.regulations.gov in docket number EPA-HQ-OPP-2003-0376. The Agency again received numerous comments from a wide range of interested parties extolling the benefits of carbaryl and are once again annotated by their document ID number as listed in docket EPA-HQ-OPP-2003-0376. In particul ar, several comments were received from

federal and state forest officials (0013, 0014, 0015, 0016, 0018, 0020, 0035) indicating that carbaryl provides superior, multi-year control of bark beetles and pine beetles in forest trees on public and private lands when compared to alte rnative insecticides. Moreover, a number of comments were submitted substantiating the import ance of carbaryl bait products as the control method of choice by state and federal agencies re sponsible for programs to control grasshoppers and Mormon crickets on private, state and federally held lands (0019, 0022, 0026, 0028, 0029, 0030, 0033, 0038, 0050, 0053, 0077).

In conclusion, while carbaryl has high-benefit uses, it also provides benefits to agricultural producers in several ways that are not always quantifiable, including broad-spectrum pest control, resistance management, fl exibility in use, and cost. Th e benefits are not uniform across crops, but can be due to localized factors or specific conditions. EPA has examined the advantages and disadvantages of carbaryl and of alternative pest control measures across a range of representative uses and determined that carb aryl provides both quantif iable and unquantifiable benefits to agriculture. Moreover, in cases where the quantifiable benefits tend to be lower, it is often because usage is low. When carbaryl is not being used, it does not present an ecological risk. Thus, upon consideration of the ecological risks (in light of the lines of evidence informing the level of risk) and the benefits provided by carbaryl use, EPA has determined that carbaryl

will not cause unreasonable adverse effects to the environment.

D. Increased Use of Carbaryl With Phas e Out of Chlorpyrifos and Diazinon.

NRDC contends that EPA’s surface water as sessment is overly optimistic because the monitoring data EPA relied upon pre-dates the cancellation of consumer uses for diazinon and chlorpyrifos. NRDC further postulates that car baryl will fill the market void created by the

- 38 -phase out and cancellation of diazinon and chlorp yrifos, thereby dramatically increasing the use of carbaryl and presence in urban runoff. NRDC cites data obta ined by the King County Department of Natural Resources (Washington state) on retail sale s of insecticides from “big box” retailers between 1997 and 2001, with sales of diazinon more than ten times higher than sales of carbaryl. However, according to NRDC, for 2002 these data show a drop of diazinon sales (by a factor of two) and a ten-fold increase in carbaryl sales. NRDC also cites an article submitted to the Journal, Environmental Toxicology and Chemistry (Dickey and Wilson 2004), which predicts that if all use of diazinon in ur ban watersheds is replaced by carbaryl, then concentrations of carbaryl could be three to four times higher th an historic diazinon concentrations, due to carbaryl’s higher mobility . Although NRDC concedes that carbaryl has a lower aquatic toxicity than diazinon, NRDC nonetheless cont ends that increased carbaryl

concentrations would be of c oncern. NRDC cites additional m onitoring data from King County

that NRDC asserts shows recent surface wate r monitoring demonstrates rising carbaryl concentrations. Finally, NRDC requests that “when EPA looks at stream monitoring data for carbaryl, product use patterns be considered and trends in pesticid e concentrations be evaluated.”

Petition at 10-11.

In connection with its concern about concentrat ions of carbaryl in drinking water, NRDC asserts that EPA has failed to pr ovide adequate documentation dem onstrating that th e benefits of increased carbaryl use exceed the identified risks, especially for urban uses. In so doing, NRDC requests that EPA consider cancellation of uses that involve the highest ecological risks and for

which alternative methods exist. Petition at 14.

It appears that NRDC is primarily criticizing the Agency for not being sufficiently prospective with respect to use trends and urging the Agency to “use its registration powers to encourage use of more selective pest management tools and discourage the widespread use of combination pesticides.” In both cases, NRDC is particular ly concerned about urban runoff. Petition at 10- 11, 14. It is, however, unclear on what basis, if any, the Petition sets forth for canceling all carbaryl registrations.

EPA disagrees with NRDC’s basic premise that carbaryl alone has supplanted consumer uses of diazinon and chlorpyrifos or that an increase in carbaryl market share has resulted in higher concentrations of carbaryl in urban runoff. Although carbaryl has gained residential/consumer market share, other pesticides, including imidacloprid, permethrin, and other synthetic pyrethroids are also gaining a significant share of the consumer market. In 2001, with chlorpyrifos and diazinon available, carbaryl ha d an estimated 25% of the residential market share, in terms of pounds applied. Carbaryl gained market share in 2004, increasing to an estimated 40% of the pounds applied by homeowners. In 2006, carbaryl market share had decreased to 35% (Kline and Co. Inc. 2007 56 ). In an alternatives assessment for carbaryl use on residential lawns, 57 EPA noted that carbaryl was likely to gain market share in the residential homeowner lawn segment due to changes in the registrations of malathion, diazinon, and chlorpyrifos. However, the move in market shar e for general lawn insects, not including white grubs and billbugs, is as likely to be towards permethrin and new synethetic pyrethroids as it is towards carbaryl. For white grub and billbug control, market shar e moves from the loss of major alternatives would likely be to permethrin and carbaryl as curativ e treatments and to

56 Kline and Co, Inc. is a market research firm that provides information regarding consumer and professional markets for pesticides.

57 Atwood D. 2007a. Alternatives Assessment for Carbaryl Use on Residential Lawns. July 13, 2007.

- 39 -imidacloprid and halofenozide as preventative trea tments. At the same time, EPA noted that use of carbaryl by lawn care professionals was on the decline and was expected to continue decreasing. At this time, the Agency does not believe that it is r easonable, prudent or scientifically defensible to speculate on future mark et trends for residential use pesticides.

Perhaps more importantly, the available su rface water monitoring data do not show a corresponding increase in aquatic exposure to carbaryl. In the process of reaching its 2007 reregistration eligibility decision for carbaryl, EPA reviewed additional monitoring data and conducted additional surface water modeling. See Revised Carbaryl Drinking Water Assessment Including Time-series Simulations (May 2, 2007). Specifically, in a summary of data collected by the NAWQA program over a decade in the Puget Sound Basin (Embrey and Moran 2006), 58
which included data on diazinon and carbaryl colle cted in Thornton Creek, it appears that after an initial increase, concentrati ons of carbaryl actually began to decline towards the end of 2005. During the first cycle, the inse cticide diazinon was often detect ed in samples from Thornton Creek; some samples were at concentrations greater than 0.1 μ g /L. The summary also shows a

decrease in diazinon detections and concentrat ions following the announcement of the phase out in 2000. There is also an increase in carbaryl de tection frequency and concentrations in the years following the announcement of the phase out of diazi non. Nonetheless, the data also appear to show that carbaryl concentrations began to de cline toward the end of the study period in 2005, rarely exceeding 0.1 μ g /L. In sum, based on data from additional surface water monitoring, EPA concludes that there does not appear to be a steady upward trend to carbaryl concentrations in urban areas following the phase ou t of diazinon and chlorpyrifos.

In addition, a recently published paper by USGS scientists evaluated trends in concentrations of carbaryl in the Northeast and Midwest afte r the phase out of di azinon and chlorpyrifos

insecticides in urban envir onments (Phillips et al. 2007). 59 They compared concentrations of these pesticides in samples collected from 20 streams by the USGS between 1992 and 2004 and

determined that 16 of these streams met criteria es tablished for assessing tr ends of carbaryl in urban streams. Sample collection and analys is followed standard NAWQA procedures for collection and analysis. Using s easonal step trend analysis, USGS evaluated the data to identify trends in summer, fall/winter, and winter/spring. Although results showed a decrease in diazinon and chlorpyrifos concentrations following the announcement of the phase out in 2000, trends were not observed in carbaryl concentrations in these regions during the same time period. Similarly, a recent report on pesticides in Calif ornia’s urban surface waters concluded that “urban use of pyrethroids, fipronil and (to a le sser extent) malathion are replacing diazinon and chlorpyrifos in the urban market.” Pesticides in Urban Surface Waters, Urban Pesticide Use Trends Annual Report (2006), compiled by the Urban Pestic ide Pollution Prevention (UP3) Project. 60 Similar findings were reported in 2007 by this same organization. 61

58 The revised carbaryl drinking water assessment incorr ectly cited this as “( Embrey and Moran 2004)”.

59 Phillips, P.J., Ator, S.W., and Nystrom, E.A., 2007, Temporal change s in surface-water insecticide after the phaseout of diazinon and chlorpyrifos: Environmental Science and Technology, v. 41, no. 12, p. 4,246–4,251..

60 The UP3 project is funded by a State Water Resources Control Board of the San Fransico Estuary Project. The 2006 annual report may be found on the internet at the URL http://www.up3project.org/documen ts/UP3_Science_Report_2006.pdf

61 The 2007 UP3 report, Pesticides in Ur ban Surface Water. Urban Uses Trends Annual Report 2007 may be found at http://www.up3project.org/documents/Final_UP3_Use_Report_2007.pdf

- 40 -With regard to the Dickey and Wilson article submitted to the Journal, Environmental Toxicology and Chemistry

, EPA was unable to review the arti cle because it was unavailable to the Agency. EPA has since learned that this artic le was rejected for publication by this journal in January 2005. Nevertheless, EPA has reviewed a report, “Toxic Tradeoff” by Erica Shreder and Phillip Dickey, which was submitted to the Agency by NRDC. 62 The Agency found that this report does not provide a ny additional information with respect to this issue. It is merely a restatement of the supposition presented in NRDC’s petition.

Finally, even if the use of carbaryl were increas ing, increases in the use of carbaryl would not be reflected in the RQs calculated for terrestrial or aquatic animals in the ecological risk

assessment. In order for the models to be eff ective screens, the Agency assumes that 100% of

the feed items to which terrestrial animals ar e exposed are treated w ith the pesticide under consideration, at the maximum allowed label rate for each crop. For the aquatic risk assessment,

the watershed in each scenario is modeled to be fully planted to the crop simulated, with 100% of that crop treated with the pesticide. Therefore, because the actual percent crop treated is not considered, increases in use will still not result in an exposure scenario as conservative as that used for the ecological screening risk assessment.

E. Modeling for urban uses.

NRDC contends that all urban uses should be “eliminated,” until EPA can establish a model and determine likely exposure. Petition at p.12. NRDC seems to be implying that EPA cannot

make its FIFRA determination and therefore must eliminate, or cancel, all urban uses in the absence of specific urban modeling.

EPA disagrees. Concentrations of carbaryl measured in surface water monitoring data were summarized in the IRED and updated in a 2007 assessment of carbaryl concentrations in drinking water (See Revised Carbaryl Drinking Water As sessment Including Time-series

Simulations (May 2, 2007)). There have been signif icant efforts to monitor agricultural and urban areas to determine carbaryl concentrations a nd as a result more monitoring is available for carbaryl than for most other pesticides. The Ag ency relied on these data to meaningfully characterize exposure in urban e nvironments. That assessment c oncluded that in urban areas, detections are more frequent and detected concentrations were mostly low (< 0.1 μ g/L). Although the peak concentration reported was as high as 16.5 μ g/L, concentrations of that magnitude were rarely measured in urban monitoring.

EPA evaluated monitoring data from Califor nia surface waters to characterize carbaryl exposure and risk in urban environments. Of the 1393 total samples repr esenting all land uses analyzed by GCMS, 0.072 percent (1 sample) contai ned levels of carbaryl sufficient to exceed the LOC for acute exposures to aquatic invertebrates ( i.e., 0.85 μ g/L); while none of the 99 total samples analyzed by HPLC contained levels sufficient to exceed the LOC for aquatic

invertebrates. The concentrati on of carbaryl in California urba n watersheds was sufficient to exceed the LOC for acute exposures to aquatic invertebrates in 0.64% of samples (1 of 157 samples) analyzed by GCMS. These data represen t another line of evidence of risk associated with carbaryl use and confirm the 2003 assessment that the screening-level risk assessment

62 See docket EQP-HQ-OPP-2005-0066.

- 41 -represents risks for a subset of vulnerable a quatic ecosystems where carbaryl is used. Although these studies typically do not incl ude low-order streams or lentic ( e.g. ponds and wetlands) environments, they do meaningfully ch aracterize exposure from urban runoff.

Moreover, subsequent to this monitoring the Ag ency did take action to mitigate exposure in urban environments. For example, liquid broadcast uses on residentia l turf have been canceled. Furthermore, in an effort to conservatively simulate an urban environment, the Agency has performed additional model runs using conservative input parameters and turf scenarios. Finally, after consultation with the Office of Water, O ffice of Pesticide Programs determined not to implement watershed basin modeling tools for sc reening assessments, due to the large amounts of input data needed for model calibration for spec ific watersheds to ensu re a reasonable level of certainty in water concentration estimates. Ho wever, subsequent to the development of the IRED for carbaryl, Office of Pesticide Program s has developed a conservative modeling tool to evaluate exposure from urban uses and has used th at tool to assess carbaryl in the California redlegged frog assessment. Therefore, the Agency is using the best tools available, and believes, because the same assumptions of 100% crop treate d for ecological risk assessment are used, that

the modeled concentrations so derive d should be considered conservative.

F. Carbaryl Use on Tidal flats

NRDC raises the issue of carbaryl use on tidal flats, reiterating comments received from the USFWS on this use of carbaryl a nd noting that a phase out for this use had been agreed to. Specifically, NRDC requests that “EPA develop a shorter timeline for phase out and assist the oyster growers in developing a safer alternative.” Petition at 13.

First, EPA does not consider this request to be a basis for canceling all ca rbaryl registrations. Second, the phase out of the carbaryl special local need registration (“Sect ion 24(c)” registration) for control of burrowing shrimp on oyster beds is a local agreement between the Washington State Department of Agriculture, and local Indian tribes, innkeep ers, and environmental groups. EPA is not a party to this phase-out agr eement or the timeline for the phase out.

Furthermore, EPA has conducted a comprehensiv e ecological risk assessment for the use of carbaryl to control burrowing shrimp in Willa pa Bay and Grays Harbor, Washington. Based upon the available data, risk to non-target organisms appear to be limited to the immediate treatment site, i.e., dewatered mud flats at low tide. Based upon landing (weight of catch) reported in the commercial crab fishery, population-level effects on crabs do not appear to be occurring as a result of carbaryl use.

G. Outstanding data

NRDC requests that EPA provide an accessibl e list of outstanding data requirements for carbaryl and that this data is received and revi ewed in a timely manner so as to inform the carbaryl risk assessment and mitigation recommendations. Petition at 15. NRDC also asserts that these data should be made publicly availa ble. In particular, NRDC mentions chronic toxicity data for bees, chronic toxicity data for estuarine/ma rine invertebrates, and consultation packages developed for the NMFS and USFWS. Th ese studies have been described in previous sections of this petition response.

- 42 -Again, these requests do not provide a basis for canceling all carb aryl registrations. In June 2003, EPA found the carbaryl database to be subs tantially complete, suffi cient to support the Carbaryl IRED. The list of outstanding data requirements at the time EPA completed the Carbaryl IRED can be found in supporting documents to the Carb aryl IRED and in Appendix B of the Carbaryl IRED. EPA issued a generic DCI for carbaryl in March 2 005 to formally require the outstanding studies mentioned by NRDC. The DCI has been scanned and will be available as part of the public docket for this petition resp onse. The Agency received most of the studies required under this DCI in 2005 and 2006; these studies were re viewed in a timely manner and incorporated into the revi sed risk assessments supporti ng the 2007 Carbaryl RED.

As previously mentioned in this document, Baye r Crop Sciences, the sole technical registrant for carbaryl, has elected not to generate wo rker exposure monitoring data for certain use

scenarios or residue data for certain food co mmodities. Accordingly, these uses are being deleted from all carbaryl product labels accord ing to a process estab lished by FIFRA Section 6(f). The only remaining outstanding data requirements are as follows:

• Carbaryl inhalation toxicity data

• Storage stability data for various commodities

• Worker exposure monitoring, aerial mi xer/loader, bait app lication to large

acreage.

As for making data publicly available, there is an established process for accessing data submitted to EPA in connection with a pestic ide registration, governed by statutory and regulatory provisions that seek to balance access with the need to protect proprietary and other

confidential business information. 63 NRDC may avail itself of that process, if it so chooses.

IV. Conclusion

In determining whether to grant NRDC’s pe tition to cancel carbaryl registrations, EPA

considered a number of factors that are described in more deta il above. The Agency considered the potential risks to workers and the environment and considered the benefits associated with carbaryl use. In terms of worker risks, carbaryl does not pose work er risks of concern, with the possible exception of the use to control grasshopp ers and Mormon crickets. With respect to this particular use, there is reason to believe that the actual risks ar e less than those reflected by the calculated MOE, few workers are exposed (and those workers tend to be highly trained), and the use has significant benefits.

As far as ecological risks are concerned, mode led carbaryl uses result in exceedences of the Agency’s screening LOCs in particular for some species of aquatic invertebrates. However, as discussed herein, the exceedance of a LOC does not n ecessarily mean that a ri sk is either real or particularly significant. Having looked more closely at carbaryl, EPA has concluded that given the purpose and inherent conservatisms in the screening-level risk assessment approach combined with the context provided by additiona l lines of evidence (m onitoring and incident data) related to the risks presen ted by carbaryl to non-listed species , the Agency can qualitatively

63 Even with respect to this issue, it is worth noting that the failure to properly disclose information to the public (which EPA does not concede occurred here) would not constitute a valid basis upon which EPA could cancel a pesticide registration.

- 43 -determine that the risks posed by carbaryl to non-listed species of aquatic life and wildlife are limited to certain taxa, in partic ular aquatic invertebra tes, affecting a limited number of species in vulnerable environments. However, the Agency concludes that while ther e could be effects to some aquatic invertebrate species in a subset of vulnerable waterbodies, not all species would be affected. In addition, existing monitoring data indicate it is unlikely th at concentrations of carbaryl in surface water will be consistently high enough to exceed the LOC for the most sensitive aquatic invertebrate sp ecies. Therefore, EPA has dete rmined that, with respect to aquatic invertebrates, carbaryl will not cause un reasonable adverse effects on the environment. Furthermore, the exposure and effects data de scribed above do not support NRDC’s contention that carbaryl use will cause the elimination of entire invertebrate communities.

The Agency’s analyses suggest that the magnit ude of benefits provide d by carbaryl varies

across different uses. As discu ssed herein, carbaryl conveys substa ntial benefits on a number of sites where it is widely used and where it is more efficacious than other alternatives. More generally, carbaryl has a relativ ely broad-spectrum of effectiv eness against a range of pests (which may obviate the need for ap plications of multiple insecticid es); it is often cheaper than many available alternatives; and it generally has a shorter PHI and REI than the alternatives, which fits well with IPM programs to disc ourage potentially u nnecessary prophylactic treatments. Moreover, having an additional chem istry available can reduce the development of pest resistance.

There are a number of sites wher e carbaryl is widely used, an d in conjunction with what EPA concludes to be a potential fo r effects that would not likely cause a significant impact on associated aquatic ecosystems in a subset of vulnerable environments, carbaryl does not pose

unreasonable risks when used on those sites. Italso appears that there are sites for which carbaryl does not have significant quantifiable benefits. However, EPA does not believe initiating cancellation action ag ainst carbaryl on those sites is appropriate for the following reasons. Given the relatively low volume of carbary l used on those sites, the Agency believes it likely that there is low risk associated with car baryl’s registration for t hose uses. The Agency

also believes that there is benef it in having a pesticide, with the characteristics of carbaryl, in reserve in case the availability of alternatives changes in the future (because, for example, of product cancellations or resistance development). And given carbaryl’s risk profile that indicates significant impacts on aquatic ecosystems are not lik ely, due to potential e ffects on some species of invertebrates, the Agency does not believe that the risks posed by carbar yl are unreasonable or

that the risks merit the initiation of formal regulatory action by EPA.

For these reasons, as well as for the reasons set forth in the 2004 IRED, the 2007 Carbaryl RED, and the 2008 Addendum to the Carbaryl RED (and supporting documentation for each), I hereby deny the Petition insofar as it seeks the cancellation of a ll carbaryl registrations. This concludes the Agency's reregistration process for carbaryl with respect to non-dietary issues.

____________________ _________________________ Date Debra Edwards, Ph.D. Director, Office of Pesticide Programs

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