Docket Number: EPA

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www.regulations.gov



# DCPA Summary Document

Registration Review: Initial Docket

June 20112 T ABLE OF C ONTENTS

Page #

I. Preliminary Work Plan 4

II. Fact Sheet 12

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

― Registration Review

– Prelimin ary Problem Formulation for the Ecological Risk Assessment of D imethyl 2,3,5,6

- T etrachloroterephthalate ( DCPA) ,‖ May 31

, 2011.

― DCPA. (Chlorthal Dimethyl). Human Health Assessment Scoping Document in Support of Registration Review ,‖ March 27, 2011.

―BEAD Chemical Profile for Registration Review: DCPA (07870 1 ),‖ January 10, 2011

.

― DCPA

- Chlorthal

- dimethyl (078701)

, Screening Leve l Usage Analysis (SLUA) ,‖ August 18, 2010

. ―Appendix A: Food/Feed & Non

- Food/Non

- Feed Uses [of DCPA] Considered in Registration Review Work Planning ,‖ December 1, 2010.

These documents are posted in the docket EPA

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I. PRELIMINARY WORK PLAN

— DCPA

Introduction

The Food Quality Protection Act of 1996 mandated a registration review program

. All pesticides distributed or sold in the United States (U.S.) generally must be regis tered by the Environmental Protection Agency (EPA or the Agency), based on scientific data showing that they will not cause unreasonable risks to human health or the environment when used as directed on product labeling. The registration review program is intended to make sure that, as the ability to assess risk evolves and as policies and practices change, all registered pesticides continue to meet the statutory standard of no unreasonable adverse effects to human health or the environment. Changes in scie nce, public policy, and pesticide use practices will occur over time. Through the registration review program, the Agency periodically reevaluates pesticides to make sure that as change occurs, products in the marketplace can be used safely. Information on this program is provided at www.epa.gov/oppsrrd1/registration_review/

. The Agency is implementing the registration review program pursuant to Section 3(g) of the Federal Insecticide, Fungicid e and Rodenticide Act (FIFRA) , and will review each registered pesticide every 15 years to determine whether it continues to meet the FIFRA standard for registration. T he Agency will consider benefits information and data as required by FIFRA. The public p hase of registration review begins when the initial docket is opened for each case. The docket is the Agency’s opportunity to state what it knows about the pesticide and what additional risk analyses and data or information it believes are needed to make a registration review decision. After reviewing and responding to comments and data received in the docket during this initial comment period, the Agency will develop and commit to a final work plan and schedule for the registration review of DCPA.

DCPA is a chlorinated benzoic acid or phthalate pre

- emergence herbicide . It is registered for use on a variety of crop and non

- crop sites, including corn, soybean, cole crops, cucurbits, peppers, herbs , and non

- residential turf and ornamentals. DCPA is used to control annual grasses and certain annual broadleaf weeds. It was first registered in the U.S. in 1958. A Reregistration Eligibility Decision was issued for DCPA in 1998 1 , and tolerances were reassessed in 2005 2

. The presence in technical

- grade DCPA of one dioxin congener and hexachlorobenzene (HCB) , both manufacturing impurities of toxic ological significance has been documented in earlier Agency decisions and documents and in the public literature

. Anticipated Risk Assessment and Data Needs

The Agenc y expects to require data for use in updating and refin ing the ecological risk assessment for DCPA (including an endangered species risk assessment) and the human health risk assessment.

1 http://www.epa.gov/oppsrrd1/REDs/0270red.pdf
2 http://www.regulations.gov/#!documentDetail;D=EPA

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Ecological risk

 The most recent ecological risk assessment for DC PA was conducted in 2009 3 . The assessment was prompted by a lawsuit brought by the Center for Biological Diversity (CBD), filed in April 2002 ( CBD v. EPA, Case No.: 02

- 1580

- JSW [JL]) 4 . The CBD alleged that the Agency failed to comply with the Endangered Species Act by not ensuring that the registration of 66 pesticide active ingredients, including DCPA, would not affect the California red

- legged frog (CRFL), a federally

- listed threatened species.

 On February 20 , 2009 , the Agency submitted a risk assessm ent and effects determination to the U.S. Fish and Wildlife Service (FWS) for the CRLF and its designated critical habitat relative to the use of DCPA in California. The Agency also requested the initiation of formal consultation with FWS. A ―likely to a dversely affect‖ determination was made for all uses of DCPA. The determination is supported by the finding of direct effects on the terrestrial phase CRLF from exposure to the parent DCPA and product impurities

, direct effects on the aquatic phase CRLF r esulting from exposure to DCPA and the degradate tetrachloroterephthalic acid ( TPA), indirect effects to the aquatic and terrestrial prey bases (plants and animals), and indirect effects to the aquatic and terrestrial habitat (plants). Modification to des ignated critical habitat is expected, primarily due to changes in the food sources for juvenile and adult CRLFs, and e ffects to terrestrial and aquatic plants of designated critical habitat are also expected. The Agency will consider any Reasonable and Pru dent Alternatives and Measures that may be included in FWS’s future responses to the Agency’s request for consultation on the CRLF.

 The most recent nation

- wide ecological risk assessment was conducted in 1998, in support of the DCPA Reregistration Eligibi lity Decision (RED). The non

- turf uses of DCPA were determined to be eligible for reregistration. The Agency was unable to make an eligibility decision for DCPA used on turf because of acute and chronic risk concerns for a range of species . T he turf deci sion was deferred until a benefits assessment was conducted , but the subsequent voluntary cancellation of residential uses obviated the need for that assessment . The RED specified certain risk management measures to reduce the ecological risks in the inte rim. These measures included: Establishing certified upper limits for the concentrations of toxicologically significant impurities in DCPA products. Instituting production caps for the period 1997 to 2000. Eliminating fall turf uses and reducing the maxim um application rate on turf. Placing surface water, groundwater, and spray drift advisories on product labels. Not all current DCPA registrations and labels reflect these risk management measures, or with the use terminations requested by the technical reg istrant and subsequently accepted by the Agency . The Agency will be working with the registrant s to bring the labels into compliance in advance of initiating the registration review risk assessments.

3 http://www.epa.gov/oppfead1/endanger/litstatus/effects/redleg

- frog/index.html#dcpa
4 http://www.epa.gov/espp/litstatus/redleg

- fr og/rlf.htm5

 On January 19, 2011, the CBD and the Pesticide Action Network North America filed

a nother lawsui t against EPA i n the U.S. District Court for the Northern District of California . The plaintiffs allege that EPA failed to under take consultation with the National Marine Fisheries Service (NMFS) and FWS regarding the effects of over 350 pesticides, including DCPA, on over 200 listed species throughout the country ( CBD , et al. v. EPA, et al., No. C 11

- 00293 (N.D.Cal.).

 Although the Agency has completed a species

- specific determination for the CRLF, an ecological risk assessment that supports a complete endangered species determination for DCPA has not been conducted

. The ecological risk assessment planned during registration review will allow the Agency to determine whether DCPA’s use has ―no effect‖ or ―may affe ct‖ federally listed threatened or endangered species or their designated critical habitats. When an assessment concludes that a pesticide’s use ―may affect‖ a listed species or its designated critical habitat, the Agency will consult with the U.S. Fish an d Wildlife Service and/or National Marine fisheries Service (the Services), as appropriate.

For use in conducting a complete ecological risk assessment, including a full endangered species assessment

, for DCPA, t he Agency anticipates requiring the followi ng data on the parent compound :

 Guideline # 835.4300 Aerobic aquatic metabolism

 Guideline # 850 .1010 Acute toxicity, freshwater invertebrates

 Guideline # 850 .1025 Acute toxicity, oyster (shell deposition)

 Guideline # 850 .1035 Acute toxicity, mysid

 Guidel ine # 850 .1075 Acute toxicity, freshwater and estuarine/marine fish

 Guideline # 850 .1300 Aquatic invertebrate life

- cycle , freshwater

 Guideline # 850.1350 Aquatic invertebrate life

- cycle estuarine/marine

 Guideline # 850.1400 Fish early life stage freshwater and estuarine/marine

 Guideline # 850

. 17 35 Whole sediment , acute invertebrates

, freshwater

 Guideline # 850

. 17 40 Whole sediment , acute invertebrates

, marine

 Guideline # 850

. 2100 Acute a vian o ral , p asserine species

 Guideline # 850.41 00 & 41 50 Vegetative vig or and se edling emergence, Tier II

 Guideline # 850.4400 Aquatic vascular plant growth

- Lemna spp. Tier II

 Guideline # 850.5400 Algal toxicity test

, Tier I/II

 Special Study: Avian inhalation toxicity, passerine species 5

The Agency anticipates requiring the following data on TPA, the major metabolite of DC PA for use in conducting a complete ecological risk assessment, including a n endangered species
assessment , for DCPA :

 Guideline # 835.1230/1240 Adsorption/desorption and leaching

 Guideline # 835.1730 Fish bioconcentration

 Guideline # 835. 212 0 Hydrolysis

5 The anticipated Data Call

- In Notice is expected to require that the test species be the most sensitive avian species as shown by avian acute oral studies (i.e, bobwhite quail)

.6

 Guideline # 835.2240 Aqueous photolysis

 Guideline # 835.2410 Soil photolysis

 Guideline # 835.4100 Aerobic soil metabolism

 Guideline # 835.4200 Anaerobic soil metabolism

 Guideline # 835.4300 Aerobic a quatic m etabolism

 Guideline # 835.4400 Anaerobic aquatic metabolism

 Guideline # 835.6100 Terrestrial field dissipation

 Guideline # 850 .1010 Acute toxicity, freshwater invertebrates

 Guideline # 850 .1025 Acute toxicity, oyster (shell deposition)

 Guideline # 850 .103 5 Acute toxicity, mysid

 Guideline # 850 .1075 Acute toxicity, freshwater and estuarine/marine fish

 Guideline # 850 .1300 Aquatic invertebrate life

- cycle , freshwater

 Guideline # 850.1350 Aquatic invertebrate life

- cycle estuarine/marine

 Guideline # 850.1400 Fi sh early life stage freshwater and estuarine/marine

 Guideline # 850

. 17 35 Whole sediment , acute invertebrates

, freshwater

 Guideline # 850

. 17 40 Whole sediment , acute invertebrates

, marine

 Guideline # 850

. 2100 Acute avian oral , p asserine species

 Guideline # 8 50

. 4150 Seedling emergence, Tier II

 Guideline # 850.4400 Aquatic vascular plant growth

- Lemna spp. Tiers II

 Guideline # 850.5400 Algal toxicity test

, Tier I/II

 The Agency anticipates assessing the toxic impurities associated with DCPA for the registratio n review. A large database already exists for these compounds and the Agency is not planning at this time to require any new compound

- specific data for the impurities that will be involved in the assessment.

 Please refer to the document ― Registration Revi ew

– Prelimin ary Problem Formulation for the Ecological Risk Assessment of D imethyl 2,3,5,6

- T etrachloroterephthalate ( DCPA) ,‖ May 31 , 2011, for a more detailed discussion of anticipated ecological risk
assessment and data needs.

Human Health Risk

 The mo st recent complete human health risk assessment (dietary, drinking water, occupational, and residential) for DCPA was conducted in support of the 199 8 RED. A n aggregate risk assessment was conducted in 2004 to support the tolerance reassessment of DCPA. Most recently, EPA conducted a screening level literature search for relevant studies.

 Tolerances established in 40 CFR § 180.185 for residues of DCPA address both crops that are treated and inadvertent residues from off

- target movement of DCPA and carry

over of residues to rotational crops. The metabolites monomethyltetrachloroterephthalate (MTP) and TPA are included in the tolerance expression for DCPA. Codex has not established maximum residue limits (MRLs)

, but MRLs are established in Canada for

seve ral commodities.7

The Agency anticipates requiring the following data for use in conducting a human health risk assessment (with dietary, water, and occupational components) for DCPA:

 Guideline # 860.1300 : Nature of the residue: poultry

 Guideline # 860. 1340 : Residue analytical method: livestock commodities

 Guideline # 860.1380: Storage stability

 Guideline # 860:1480: Meat/milk/poultry/eggs : ruminants

 Guideline # 860.1900: Field accumulation in rotational crops

 Guideline # 870.7800 : Immunotoxicity

 Guideline # 870.3465 : Subchronic inhalation toxicity study

— 28 day

 Guideline # 870.6200: Neurotoxicity battery (acute and subchronic studies)

 Special Study : Comparative thyroid stud y

 Adequate toxicity data exist for the manufacturing impurities in DCPA and the Agency does not anticipate requiring any additional data on the impurities

. Human health ri sks associated with the manufacturing impurities in DCPA were assessed at the time of the RED . The Agency will work with the registrant of technical grade DCPA to establish if and how levels of these impurities have change d si nce the previous assessment. Depending in part on any such changes, the Agency will determine whether or not to conduct a new assessment of the impurities in DCPA.

 Please refer to the document ― DCPA. (Chlorthal Dimethyl). Human Health Assessment Scoping Document in Support of Registration Review,‖ March 27 , 2011, for a more detailed discussion of human health risk estimates and anticipated human health risk
assessment and data needs.

Endocrine Disruptor Screening Program

As required by FIFRA and FFDCA, EPA reviews numerous studies to assess potential adverse outcomes from exposure to chemicals. Collectively, these studies include acute, subchronic and chronic toxicity, including asse ssments of carcinogenicity, neurotoxicity, developmental, reproductive, and general or systemic toxicity. These studies include endpoints which may be susceptible to endocrine influence, including effects on endocrine target organ histopathology, organ wei ghts, estrus cyclicity, sexual maturation, fertility, pregnancy rates, reproductive loss, and sex ratios in offspring. For ecological hazard assessments, EPA evaluates acute tests and chronic studies that assess growth, developmental and reproductive eff ects in different taxonomic groups. As part of its re registration decision , EPA reviewed these data and selected the most sensitive endpoints for relevant risk assessment scenarios from the existing hazard database. However, as required by FFDCA section 408(p), DCPA is subject to the endocrine screening part of the Endocrine Disruptor Screening Program (EDSP).

EPA has developed the EDSP to determine whether certain substances (including pesticide active and other ingredients) may have an effect in humans or wildlife similar to an effect produced by a ―naturally occurring estrogen, or other such endocrine effects as the Administrator may designate.‖ The EDSP employs a two

- tiered approach to making the statutorily required determinations. Tier 1 consists o f a battery of 11 screening assays to identify the potential of a8

chemical substance to interact with the estrogen, androgen, or thyroid (E, A, or T) hormonal systems. Chemicals that go through Tier 1 screening and are found to have the potential to inter act with E, A, or T hormonal systems will proceed to the next stage of the EDSP where EPA will determine which, if any, of the Tier 2 tests are necessary based on the available data. Tier 2 testing is designed to identify any adverse endocrine

- related effe cts caused by the substance, and establish a dose

- response relationship between the dose and the E, A, or T effect.

Under FFDCA section 408(p), the Agency must screen all pesticide chemicals. Between October 2009 and February 2010, EPA issued test orders/ data call

- ins for the first group of 67 chemicals, which contains 58 pesticide active ingredients and 9 inert ingredients. DCPA was included on that list and was issued an order to conduct the Tier 1 testing on October 29, 2009

. Once all required Tier 1 and Tier 2 data have been received and reviewed, the endpoints and safety factors used for risk assessment purposes will be examined and a new risk assessment performed if necessary. For further information on the status of the EDSP, the policies and
proc edures, the list of 67 chemicals, future lists, the test guidelines and the Tier 1 screening battery, please visit our website: http://www.epa.gov/endo/

.

Timeline

The projected timeline for the DCPA registration re view appears in the table below.

Projected DCPA Registration Review Timeline Activities Estimated Date Opening the D ocket Open Docket and Begin Public Comment Period 2011

– June Close Public Comment Period 2011

– August Case Development Final Work Plan 2011

– November Issue DCI 2012

– July

– Sept. Data Submission 2014

– July

– Sept. Open Public Comment Period for Draft Risk Assessments 2016

– Jan.

– March Close Public Comment Period 2016

– April

– June Registration Review Decision Open Pu blic Comment Period for Proposed Registration Review D ecision 2016

– July

– Sept.

Close Public C omment P eriod 2016

– Oct.

– Dec. Registration Review D ecision and Begin P ost

- D ecision F ollow

- up 2017 Total ( years ) 6

Guidance for Commenters; Solicit ation of Information

The public is invited to comment on EPA’s preliminary work plan and rationale. The Agency will carefully consider all comments, and any additional information that is provided in a timely manner, prior to issuing a final work plan for the DCPA registration review case.9

Trade Irritants

Through the registration review process, the Agency intends to solicit information on trade irritants and, to the extent feasible, take steps toward facilitating irritant resolution. Growers and other stakeholders are asked to comment on any trade irritant issues resulting from lack of Maximum Residue Limits (MRLs) or disparities between U.S. tolerances and MRLs in key export markets, providing as much specificity as possible regarding the nature of the concern.

Water Quality

DCPA is identified as a cause of impairment , as defined under section 303(d) of the Clean Water Act , for one water body in California 6

. In addition, a Total Maximum Daily Load (TMDL) has been developed for DCPA in the same waters hed 7 . More information on impaired water bodies and TMDLs can be found at the Agency’s website 8

. The Agency invites submission of water quality data for th is pesticide. To the extent possible, data should conform to the quality standards in Appendix A of the OPP Standard Operating Procedure: Inclusion of Impaired Water Body and Other Water Quality Data in OPP’s Registration Review Risk Assessment and Management Process 9 in order to ensure they can be used quantitatively or qualitatively in pesticide risk assessments.

Environmental Justice

EPA seeks to achieve environmental justice, the fair treatment and meaningful involvement of all people, regardless of race, color, national origin, or income, in the development, implementation, and enforcement of envi ronmental laws, regulations, and policies. To help address potential environmental justice issues, the Agency seeks information on any groups or segments of the population who, as a result of their location, cultural practices, or other factors, may have atypical, unusually high exposure to DCPA compared to the general population. Please comment if you are aware of any sub

- populations that may have atypical, unusually high exposure, compared to the general population.

Additional Information

Stakeholder s are asked to provide additional information that will assist the Agency in refining its risk assessments for DCPA, including any species

- specific ecological effects determinations. The Agency particularly is interested in receiving the following informa tion: 1. DCPA human, domestic animal, or ecological incidents not already reported to the Agency.

2. Information on or confirmation of the following use parameters for each registered use of DCPA : Sites of application Formulation type

6 http://iaspub.epa.gov/tmdl_waters10/attains_nation_cy.cause_detail_303d?p_cause_group_id=885

7 http://iaspub.epa.gov/tmdl_waters10/attains_nation.tmdl_pollutant_detail?p_pollutant_group_id=885&p_pollutant_group_name=PEST ICIDES
8 http://www.epa.gov/owow/tmdl/
9 http://www.epa.gov/oppsrrd1/registration_review/water_quality_sop.htm10

Application meth ods and equipment Maximum application rates expressed as mass ai per unit area, typical application rates Factors affecting application rate, e.g ., weather, disease pressure, fresh/processed commodity Application intervals, frequency of application, fact ors affecting frequency of application Application timing (date of first application and typical application intervals) by use

– national, state, and county Maximum number of applications per year (or season, as appropriate)

3 . Use or potential use dist ribution ( e.g ., geographical distribution of uses, areas of greatest use)

.

4

. General u se history

.

5

. Median and 90th percentile reported use rates from usage data

– national / state /county.

6 . Sub

- county use site data

.

7. Usage data for non

- agricultu ral uses (e.g., golf course turf, combination herbicide/fertilizer products, nursery stock, non

- residential ornamental s/ shade trees / ground cover s , sod farm turf .)

8 . Directly acquired county

- level usage data (not derived from state level data). Maximum r eported use rate from usage data

– county Median and 90th percentile number of applications

– county Total pounds per year

– county Year the pesticide was last used in the county/sub

- county area (if no longer used), and/or Years in which the pesticide w as applied in the county/sub

- county area

.

9 . State, local or other geographic use restrictions

. 10. Any adverse effects in honey bees associated with the use of DCPA products.

11 . Co

- formulation or tank

- mixing of DCPA and other pesticides

— is DCPA typi cally applied with other pesticides?

Next Steps

After the 60

- day comment period on this PWP closes, the Agency will review and respond to comments that have been submitted in a timely manner , and then issue a Final Work Plan (FWP) for this pesticide. A s indicated above, t he Agency expects to issue the FWP for DCPA in November 2011

.11 II. FACT SHEET: DCPA Registration Review Background Information for DCPA

 Registration review case number: 0270

 Pesticide Chemical (PC) Code: 078701

 Chemical Abstracts Se rvice (CAS) number: 1861

- 32

- 1

 Other names: dacthal, chlorthal dimethyl, and d imethyl 2,3,5,6

- t etrachloroterephthalate

 Chemical Class: chlorinated benzoic acid or phthalate

 DCPA was first registered in the U.S. in 19 58

.

 A RED was completed in 199 8

.

 In 2 005, the Agency reassessed DCPA tolerances; at the same time, the residential turf and ornamental uses and several other uses of DCPA were terminated at the request of the registrant 10

.

 There are two technical

- grade DCPA registrations, both held by Amvac. Three registrants hold a total of eight Section 3 end

- use product registrations.

 There is one active FIFRA Special Local Need 24(c) product registered with the Agency

, from the state of Wisconsin, for the use of DCPA on ginseng

.

Contact information

 Pes ticide Re

- evaluation Division: Jill Bloom; bloom.jill@epa.gov

 Registration Division: Kay Montague; montague.kathryn@epa.gov

Use & Usage Information

The Agency has con ducted a Screening Level Usage Analysis (SLUA) for DCPA and characterized the use parameters for DCPA. The Chemical Profile, SLUA

, and ―Appendix A‖ (as the listing of use parameters is known) are available in the DCPA registration review docket.

 DCPA is a pre

- emergence herbicide registered for use on a variety of crop and non

- crop sites, including corn, soybean s , cole crops, cucurbits, onions, tomatoes, peppers, herbs

, and non

- residential turf and ornamentals . DCPA is used to control annual grasses and certain annual broadleaf weeds.

 Between 1998 and 2008, agricultural usage of DCPA averaged approximately 500,000 pounds on 100,000 acres.

 In 2000, a pproximately 1 million pounds of DCPA w ere used by consumers in lawn herbicides an d an additional 1.8 mil lion pounds were used in the form of herbicide/fertilizer combination products. Since that time, usage in this sector is believed to have declined as labels come into compliance with the voluntary use terminations referenced above.

 End

- use products are fl owable concentrates, wettable powders, and granulars

.

 DCPA is typically applied at a rate of 4

- 6 lbs ai per acre. Products may be applied via broadcast spray (aerial or ground)

, chemigation, band treatment, and soil injection.

10 http://www.regulations.gov/ #!documentDetail;D=EPA

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Application equipment inclu des broadcast sprayers, spreaders, shaker

- cans, sprinkler irrigation, and soil injection equipment.

 The yearly ma ximum application amount s, maximum number of applications , and minimum retreatment intervals are not specified on all DCPA product labels. Th e Agency is working with the registrants to correct these deficiencies.

Recent and Related Actions

 No recent activity; no actions pending.

Manufacturing I mpurities of T oxicological C oncern
The Agency is aware that the manufacturing process for DCPA t echnical

- grade material results in the formation of impurities of toxicological significance. The Agency is working with the registrant to assure that the presence of these impurities is accurately characterized in the Confidential Statement of Formula fo r the technical material.

Additionally, the Agency is working with the registrant to implement previously specified labeling that notes the presence of the toxic impurities in the technical formulation.

Ecological Risk Assessment Status

Refer to the su pporting documents, including ― Registration Review

– Prelimin ary Problem Formulation for the Ecological Risk Assessment of D imethyl 2,3,5,6

- T etrachloroterephthalate ( DCPA) ,‖ May 31

, 2011, for a discussion of the most current ecological risk and endangered species assessments

.

 DCPA is relatively persistent in the environment and has a tendency to bioaccum ul ate in aquatic organisms.

 The metabolite TPA forms at high levels relative to parent chemical in the environment

. TPA is expected to be more mobile th an DCPA and be somewhat persistent in the environment. Toxicology data are available for mammals only.

 Monitoring data indicate widespread occurrence of DCPA in surface water, groundwater, drinking water, and air. DCPA and TPA are two of the most commonl y found pesticides/

pesticide metabolites found in water samples

.

 It does not appear that acute exposure to DCPA results in mortality in f reshwater or estuarine/marine fish at the limit of solubility (0.5 ppm). C hronic effects for freshwater and estuarine/ marine fish are uncertain because no chronic data have been submitted.

 Definitive DCPA toxicity test data for aquatic plants are lacking because of the limited solubility of DCPA in water

. Based on the number of target species and the adverse effects ob served in aquatic plant toxicity studies, effects on aquatic plants can be expected at or below the limit of solubility for DCPA in water.

 The results of reproductive toxicity tests in birds are not reliable for use in a quantitative risk assessment, in pa rt because the overall health of the test animals was compromised at the outset of testing

.13

 A vailable data from testing in rats indicate that the adverse effects associated with TPA are much milder than those for the parent and tend to occur at doses that are lower by approximately an order of magnitude. No corresponding data are available for the metabolite MTP

.

 Available scientific literature will be used characterize the toxicity and risk associated with the presence of manufacturing impurities in DCPA

.

Human Health Risk Assessment Status

Past DCPA risk assessments rel ied in part on data from studies in which adult human subjects were intentionally exposed to a pesticide to determine their dermal and inhalation exposure. Many such studies, involving e xposure to many different pesticides, comprise generic pesticide exposure databases such as the Pesticide Ha ndlers Exposure Database (PHED) and the Agricultural Reentry Task Force (ARTF) Database

. EPA has reviewed all the studies supporting these multi

- pe sticide generic exposure databases, and has found no clear and convincing evidence that the conduct of any of them was either fundamentally unethical or significantly deficient relative to the ethical standards prevailing at the time the research was condu cted. A ll applicable requirements of EPA’s Rule for the Protection of Human Subjects of Research (40 CFR Part 26) have been satisfied , and t here is no regulatory barrier to continued reliance on these studies

. Please refer to the support documents, inclu ding ― DCPA . (Chlorthal Dimethyl). Human Health Assessment Scoping Document in Support of Registration Review ,‖ March 27 , 2011, for a discussion of the status of the human health risk assessment. The health risk assessment conducted for the 199 8 RED result ed in the following conclusions:

 In long term studies with DCPA, treated animals manifested thyroid toxicity as shown by decreased levels of thyroid hormone, microscopic thyroid changes, and increased thyroid weight. Effects on the liver were also manife sted, as increased liver weight, elevated liver enzyme activity, increased cholesterol, and liver hypertrophy. It is believed that the liver effects are precursor events to the thyroid effects, with increased metabolism of thyroid hormone by the liver res ulting in a compensatory stimulation of the thyroid. Effects on the kidney have also been observed

.

 There were no mutagenicity concerns for DCPA , but t hyroid follicular cell adenomas/ carcinomas, hepatocellular adenomas/carcinomas , a nd hepatocholangiocarcinomas were found in exposed rats ; hepatic adenomas were found in exposed mice. DCPA is classified a Group C (possible human) carcinogen

.

 Post

- application risks for children to DCPA from residential applications were at a level typic ally associated with risks of concern. Although the RED indicated that the Agency was deferring its decision on the eligibility of the residential uses of DCPA for reregistration, these risks were addressed with the subsequent voluntary terminatio n of

res idential uses of DCPA.

 Occupational risk estimates for DCPA were reduced to below the level of concern with label requirements for personal protective equipment (handlers wearing baseline clothing + gloves and dust/mist respirators) and with a Restricted

- Entry Interval of 12 hours.

 T he Agency conclude d that DCPA does not pose a significant chronic or carcinogenic dietary risk

.14

Toxic impurities

 Toxic impurities reported to be present in technical

- grade DCPA product were assessed at the time of the RED

.

 Dietary risk estimates for the toxic impurities in DCPA were below the level of concern.

 Post

- application risks for children to the toxic impurities in DCPA from residential uses were at a level typically associated with risks of concern. These risks were addressed after the RED was issued by the voluntary termination of residential uses of DCPA.

 Occupational risk estimate s for the impurities were below the Agency’s level of concern.

Cumulative assessment

 The Agency has not determined whether DCPA s hares a common mechanism of toxicity with other chemical substances. If, in the future, the Agency determines that new information on DCPA is available that could potentially impact a cumulative risk assessment and result in a risk of concern, the Agency w ill revisit the need for a cumulative risk assessment.

Incident Reports

 The OPP Incident Data System (IDS) contains few incident reports citing a connection to the use of DCPA. Based on the low frequency and severity of incident cases, there does not ap pear to be a concern at this time that would warrant further investigation of incidents involving DCPA

. The Agency will continue to monitor the incident information and

, if a concern is triggered, additional analysis will be included in the risk

assessmen t.

 The Ecological Incident Information System (EIIS, version 2.1) maintained by the Office of Pesticide Programs, and the Avian Monitoring Information System (AIMS), maintained by the American Bird Conservancy, document two incidents in which DCPA was appl ied in close proximity to the area in which the incidents occurred or residues of DCPA were found in affected animals. The incidents involved fish and bird kills.

Tolerances and International Harmonization

 Tolerances for DCPA are located at 40 CFR § 18 0. 185 11

.

 There are no Codex MRLs for DCPA. Canada has established MRLs for commodities from treated crops 12

. The Canadian MRLs are the same as the U.S. tolerances for the commodities they have in common, with the exception of values for collards and kale (2 ppm MRL, 5 ppm tolerance).

 During registration review, the Agency will work to harmonize tolerances and MRLs as

11 http://e cfr.gpoaccess.gov/cgi/t/text/text

idx?type=simple;c=ecfr;cc=ecfr;sid=701e5927a66383fe112f5dff728d547d;idno=40;region=DIV1;q1=DCPA;rgn=di v8;view=text;node=40%3A23.0.1.1.28.3.19.40
12 http://www.hc

- sc.gc.ca/cps

- spc/pest/part/consultations/_prvd2008

- 18/index

- eng.php15

appropriate. In addition, the residue definition will be modified in accordance with current policy

.

Labels

 Images of the labels of reg istered DCPA products can be obtained from the Pesticide Product Label System (PPLS) website at http://oaspub.epa.gov/pestlabl/ppls.home

.