Docket Number: EPA-HQ-OPP-2010-0923 www.regulations.gov



## Chlorpropham Final Work Plan Registration Review

June 20113 CHLORPROPHAM FINAL WORK PLAN

Introduction :

This is the Environmental Protection Agency’s (EPA’s) Final Work Plan for the registration review of chlorpr opham. This work plan includes the expected registration review timeline. The work plan also addre sses public comments received concerning the Preliminary Work Plan (PWP) in the Summary Document , which was posted in the chlorpropham registration review dock et (EPA-HQ-OPP-2010-0923), and any other comments concerning the ini tial docket postings. The Summary Document provided information on what EPA knows about the pest icide and what additional risk analyses and data or information the Agency believes are needed to make a registration review

decision.

The Agency is implementing the registra tion review program and will review each registered pesticide every 15 years to determin e whether it continues to meet the Federal Insecticide, Fungicide, and R odenticide Act (FIFRA) standard for registration. Changes in science, public policy, and pesticide use practices will occur over time. The registration review program is intended to ma ke sure that, as the ability to assess risk evolves and as policies and pract ices change, all registered pe sticides continue to meet the statutory standard. The public phase of registration review begins when the initial docket is opened for each case. Inform ation on this program is provided at: http://www.epa.gov/oppsrr d1/registration_review/

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Chlorpropham (Case 0271) is a carbamate plant growth regulator registered for use for sprout control on post-harvest, stored potatoes. Chlorpropham is not an N- methyl

carbamate and does not share a common mechanism of toxicity with the N- methyl carbamate group. Also, Special Local Need (SLN) registrations for chlorpropham allow chlorpropham use to prevent bud formation on ginkgo trees in Washington, D.C. and to prevent bud formation and control Botrytis on Easter lilies in Ca lifornia and Oregon. There are currently no residentia l uses for chlorpropham. The Reregistration Eligibility Decision (RED) for Chlorpropham was completed in October 1996 and the Report of FQPA Tolerance Reassessment Progress and Interim Risk Management Decision (TRED) for Chlorpropham was completed in September 2002

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Updates since Preliminary Work Plan was Issued :

After further review of the existing ecological data available for chlorpropham, the Agency has determined that environmental chemistry methods and associated independent laboratory validations for soil and water are necessary to complete the forthcoming ecological risk assessment for re gistration review. These data requirements were not specified in the Preliminary Work Plan or in the Registration Review: Preliminary Problem Formul ation for Environmental Fa te and Ecological Risk, Endangered Species, and Drinking Water Ex posure Assessments for Chlorpropham

, dated November 4, 2010. These additional data requirements are reflected in this Final

Work Plan

.4 For further details regarding changes to the data requirements refer to the Followup to EFED’s Response to Comments on Chlorpropham: Outstanding Data Gaps , dated May 26, 2011, which can be located in the chlorpr opham registration review docket (EPAHQ-OPP-2010-0923).

Comments Received on Preliminary Work Plan :

The chlorpropham registration review docket was open for a 60-day comment period beginning on December 22, 2010. During the public comment period the Agency received multiple comments from Keim Aerosol Technologies and by Technology Sciences Group, Inc. The comments received did not change the planned risk assessment, data needs or the timeline detailed in the chlorpropham Preliminary Work

Plan (PWP). EPA also solicited comments, th rough the PWP, on three specific topics: environmental justice, water body impairment, and trade irritants. No comments or information were received during the comment period concerning these issues. Further, this document makes final the work plan fo r the chlorpropham registration review

process.

A general overview of the comments and the Agency’s responses to the comments are presented in the Summary of Comments and Agency Responses section of this document.

Risk Assessment and Data Needs :

The Agency will conduct a comprehensive ec ological risk assessment, including an endangered species assessment, and intends to update the existing human health risk assessments for all uses of chlorpropham. The Agency will require data in order to conduct the planned human health and ecologica l risk assessments. Below is a summary of the ecological and human health issues relevant to the regi stration review of chlorpropham:

Ecological Risk:

• The most recent ecological assessment for chlorpropham was completed in 1996 in support of the chlorpropham Reregist ration Eligibility Decision (RED).

• An ecological risk assessment of all re gistered uses of chlorpropham will be conducted during registration review. The new assessment will incorporate the most up-to-date modeling methodologies, updated toxicological endpoints, and data submitted under the anticipated registration review data call-in.

• The Agency has not conducted a risk assessment that supports a complete endangered species determination for chlorpropham. The ecological risk assessment planned during registration revi ew will allow the Agency to determine whether chlorpropham use has “no effect ” or “may affect” federally listed threatened or endangered species (listed species) or their designated critical

habitats. When an assessment conclude s that a pesticide’s use “may affect” a5 listed species or its designated critical habitat, the Agency will consult with the

U.S. Fish and Wildlife Service and/or Na tional Marine Fisher ies Services (the Services), as appropriate.

• The Agency will require the following data in order to conduct the planned ecological risk assessment, including an endangered species assessment, for all

uses:

 Guideline No. 835.1230 – Sediment and Soil Absorption/Desorption

 Guideline No. 835.1240 – Soil Column Leaching

 Guideline No. 835.4100 – Aerobic Soil Metabolism

 Guideline No. 835.6100 – Environmental chemistry method and associated independent labor atory validation for soil

 Guideline No. 835.6200 – Environmental chemistry method and associated independent labor atory validation for water

 Guideline No. 850.1300 – Daphnid Chronic Toxicity

 Guideline No. 850.1400 – Fish Early-Life Stage Toxicity, freshwater

 Guideline No. 850.2100 – Avian Acute Oral Toxicity, Passerine

 Guideline No. 850.2300 – Avian Reproduction

 Guideline No. 850.4100 – Nontarget Area Phytotoxicity Tier II, Seedling

emergence

 Guideline No. 850.4150 – Nontarget Area Phytotoxicity Tier II, Vegetative vigor

 Guideline No. 850.4400 – Nontarget Area Phytotoxicity Tier II, Aquatic Plant Growth (Vascular plants)

 Guideline No. 850.5400 – Nontarget Area Phytotoxicity Tier II, Aquatic Plant Growth (Algal plants)

• Please refer to the Registration Review: Prelimin ary Problem Formulation for Environmental Fate and Ecological Risk, Endangered Species, and Drinking Water Exposure Assessments for Chlorpropham, dated November 4, 2010 ; the Followup to EFED’s Response to Comments on Chlorpropham: Outstanding Data Gaps , dated May 26, 2011; and the Environmental Fate and Effects Division Response to Comments on Registration Review Problem Formulation for Chlorpropham , dated April 14, 2011, located in the registration review docket (EPA-HQ-OPP-2010-0923) for a detailed disc ussion of the risk assessment and

data needs.

Human Health Risk :

• The most recent human health risk a ssessment, including an updated drinking water assessment, was completed in 2002 in support of the ch lorpropham TRED.

• During registration review, the Agency will conduct a new drinking water assessment for the Easter lily use and the amount of chlorpropham that deposits from the aerial release into the environment from the stored potato use.6 • The Agency will conduct a new dietary ri sk assessment, incorporating refined estimated drinking water concentrations (EDWCs), updated anticipated residues, and Pesticide Data Program (PDP) data.

• The chlorpropham tolerance expression will be reviewed during registration review to ensure that it appropriately covers the metabolites and degradates of chlorpropham and that it specifies the residues to be measured for each commodity.

• The residue chemistry database is suffici ent to support the current registrations; however, there are some outstanding data requirements concerning the analytical methods. These data were required by a previous Data Call-In (DCI) for chlorpropham issued in April 1994. These data, when submitted and found acceptable, will complete the residue chemistry data requirements for chlorpropham. The, outstanding data are:

 Guideline No. 171-4d – Residue Analyt ical Method - Animal: A revised analytical method for tolerance enfor cement in stored potato commodities.

The Agency is currently reviewing data submitted to fulfill the requirement for Residue Analytical Me thod – Animal. If this data is found acceptable, no further submissions will be necessary to fulfill this requirement.

 Guideline No. 171-4j – Magnitude of Residue in meat/milk/poultry/egg: Independent laboratory validation for the enforcement method to detect chlorpropham and its 4-HAS me tabolite in meat and milk.

For the Magnitude of Residue in meat/milk/poultry/egg data requirement, an analytical detection method was submitted to the Agency and found to be scientifically acceptable. However, the method did not include an independent laboratory validation (ILV). The data requirement will be considered fulfilled when an acceptable ILV is submitted. The technical registrants for chlorpropham have be en made aware of this deficiency.

• Occupational exposures have not been prev iously assessed for ai rblast application to ginkgo trees and for the post-application use on Easter lilies. In addition, the previously assessed occupa tional handler exposure scenarios did not include estimates of inhalation exposure. Ther efore, the Agency will be conducting a revised occupational exposure asse ssment during registration review.7 • The toxicity database is complete with the exception of the following studies, which the Agency will be requiring in or der to conduct a complete human health

assessment:

 Guideline No. 870.3465 – 90-day Inhalation-Toxicity

 Guideline No. 870.6200 – Acute and Subchronic Neurotoxicity

 Guideline No. 870.7800 – Immunotoxicity

Please refer to the Chlorpropham. Human-Health Assessment Scoping Document in Support of Registration Review, dated November 2, 2010; and the Chlorpropham. Public Comments Regarding the Health Effects Divi sion’s (HED’s) Hum an-Health Assessment Scoping Document in Support of Registration Review of 02- NOV -2010. HED’s Response

to Public Comments , dated May 17, 2011, located in the registra tion review docket (EPAHQ-OPP-2010-0923) for a detailed discussion of the risk assessment and data needs.

Endocrine Disruptor Screening Program :

As required by FIFRA and FFDCA, EPA review s numerous studies to assess potential adverse outcomes from exposure to chemicals. Collectively, these studies include acute,

subchronic and chronic toxici ty, including assessments of carcinogenicity, neurotoxicity, developmental, reproductive, and general or systemic toxicity. These studies include endpoints which may be susceptible to e ndocrine influence, including effects on endocrine target organ histopathology, organ weights, estrus cyclicity, sexual maturation, fertility, pregnancy rates, re productive loss, and sex ratios in offspring. For ecological hazard assessments, EPA evaluates acute test s and chronic studies that assess growth, developmental and reproductive effects in di fferent taxonomic groups. As part of its reregistration decision

, EPA reviewed these data and selected the most sensitive endpoints for relevant risk assessment scenar ios from the existing hazard database. However, as required by FFDCA section 408( p), chlorpropham is subject to the endocrine screening part of the Endocrine Disruptor Screenin g Program (EDSP).

EPA has developed the EDSP to determine whether certain substances (including pesticide active and other ingred ients) may have an effect in humans or wildlife similar to an effect produced by a “natur ally occurring estrogen, or othe r such endocrine effects as the Administrator may designate.” The ED SP employs a two-tiered approach to making the statutorily required determinations. Tier 1 consists of a battery of 11 screening assays to identify the potential of a chemical substa nce 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 inte ract with E, A, or T hormonal systems will proceed to the next stage of the EDSP wher e EPA will determine which, if any, of the Tier 2 tests are necessary based on the availa ble data. Tier 2 te sting is designed to identify any adverse endocrine-related eff ects 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 group8 of 67 chemicals, which contains 58 pesticide active ingredient s and 9 inert ingredients. Chlorpropham is not among the group of 58 pestic ide active ingredients on the initial list to be screened under the EDSP. Accordingly, as part of registra tion review, EPA will issue future EDSP orders/data call-ins, re quiring the submission of EDSP screening assays for chlorpropham. For further information on the status of the EDSP, the policies and procedures, the list of 67 chemicals, futu re lists, the test gui delines and the Tier 1 screening battery, please visit our website: http://www.epa.gov/endo/

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Timeline :

EPA has created the following timeline for completion of the registration review for chlorpropham.

Registration Review for Chlorpropha m – Registration Review Timeline

Activities Estimated Date Opening the Docket Open Docket and Public Comment Period 2010 – December Close Public Comment 2011 – February Case Development

Final Work Plan 2011 – June

Issue DCI 2012 – Jan. – March

Data Submission 2014 – Jan. – March Open Public Comment Period for Draft Risk Assessments 2015 – July – Sept.

Close Public Comment Period 2015 – Oct. – Dec. Registration Review Decision Open Public Comment Period for Proposed Registration Review

Decision 2016 – Jan. – March

Close Public Comment Period 2016 – April – June Registration Review Decision and Begin Post-Decision Follow-up 2016 Total (years) 6

Summary of Comments & Agency Responses :

The chlorpropham registration review docket was open for a 60-day comment period beginning on December 22, 2010. During the co mment period, multiple comments were submitted by Keim Aerosol Technologies (Keim) and by Technology Sciences Group, Inc. (TSG). The comments received do not chan ge the risk assessment, data needs or the timeline detailed in the chlorpropham Preliminary Work Plan (PWP). A general summary of these comments and the Agen cy’s response to comments are provided

below.

For a detailed description of the comments received and the Agency’s response to these comments please refer to the following two documents: Chlorpropham. Public Comments Regarding the Health Effects Divi sion’s (HED’s) Hum an-Health Assessment Scoping Document in Support of Registra tion Review 02-NOV-2010. Chlorpropham.9 Public Comments Regarding the Health Eff ects Division’s (HED’s) Human-Health Assessment Scoping Document in Support of Registration Review of 02-NOV 2010. HED’s Response to Public Comments , dated May 17, 2011; and Environmental Fate and Effects Division Response to Comments on Regi stration Review Problem Formulation for Chlropropham , dated April 14, 2011. These documents are available in the chlorpropham docket (EPA-HQ-OPP-2010-0923).

Keim Aerosol (Keim) Technologies

Keim Comments on Ecological Risk :

Concerning ecological risk, Keim’s commen ts dealt primarily with the Agency’s assumption that chlorpropham may be released into the environment after use in sealed potato storage facilities.

Agency Response :

Currently, the Agency assumes that some chlorpropham may be released into the environment as a result of the stored potato use. However, if submitted, the Agency will consider monitoring data on releases of ch lorpropham following the indoor stored potato

use.

Keim Comments on Human Health Risk :

Concerning human health risk, Keim Aeroso l’s comments dealt primarily with the Agency’s assumptions concerning worker risk, dietary exposure to chlorpropham residues, and current applica tion methodologies. Keim asserts that current assessment assumptions are inadequate to address the human health risks posed by chlorpropham.

Additionally, Keim commented on the need fo r chlorpropham product labels to provide guidance on how to prevent fires and explos ions during treatment in potato storage

facilities.

Agency Response :

For a detailed discussion of the Agency’s response to Keim’s comments please refer to

the Chlorpropham. Public Comments Regarding the Health Effects Division’s (HED’s) Human-Health Assessment Scoping Document in Support of Regist ration Review of 02- NOV 2010. HED’s Response to Public Comments , dated May 17, 2011, located in the chlorpropham registration review docket . In its response document, the Agency addresses the deficiencies Keim claims exist in the Agency’s assessment assumptions and methodologies. Detailed descriptions of how the Agency assesses various facets of dietary and occupational risk are also provided. Additionally , the Agency clarifies label

use directions and describes the reliability of common sources of data used for risk assessment, such as the USDA Pesticide Data Program.10 In response to Keim’s comment regarding pr oduct label guidance, the Agency notes that during the Agency’s review process for pr oduct labels, those products whose chemistry data indicate a potential flammability con cern are required to include precautionary language on their labels. Add itional information is available in Chapter 9 in the EPA Label Review Manual ( http://www.epa.gov/oppfead1/labeling/lrm/chap-09.pdf ).

Technology Sciences Group Inc. (TSG)

TSG Comments on Ecological Risk :

Concerning ecological risk, TSG questioned th e Agency’s assumption that chlorpropham may be released into the environment after us e in sealed potato st orage facilities. TSG

also noted that their members do not have ch lorpropham products registered for any uses other than the indoor potato use. TSG did not believe that any of the fate and ecological data requirements described in the PWP were applicable to assessment of ecological risk resulting from the potato use.

Agency Response :

The Agency thanks TSG for their comments; however, they do not alter the Agency’s assumption that the indoor potato storage us e of chlorpropham may result in release of chlorpropham into the environment, and, theref ore, the identified fate and ecological data

outlined in this Final Work Plan are required in order to su pport the planne d ecological risk assessment. However, if submitted, the Agency will consider monitoring data on releases of chlorpropham following the indoor potato storage use.

TSG Comments on Human Health Risk :

Concerning human health risk, TSG’s comments dealt with the Agency’s proposed data requirements and worker exposure assumptions. TSG cited several studies they felt may address data gaps identified in the PWP . Additionally, TSG commented that, since their products are only registered for use indoors on stored potatoes, several of the studies
were unnecessary to assess risk for the potato use.

Agency Response :

Due to the potential for occupational exposure from the stored potato use, the data that the Agency plans to require for the human heal th assessment did not change as a result of

the comments. TSG cited several studie s which may provide some information on neurotoxicity and immunotoxicit y. However, studies not sp ecifically conducted to assess these toxcicological endpoints may be inadequate to charact erize a pesticide’s potential neurotoxicity or immunotoxicity. The Agency plans to require th e toxicological data

described in the PWP.11 Next Steps :

The Agency plans to develop a Data Call-In No tice for this pesticide and plans to issue it in early 2012. This new information will be used to conduct risk assessments for chlorpropham uses.

Summary of Data Gaps – Chlorpropham :

The table below summarizes all data need s for chlorpropham identified in the Ecological

Risk and Human Health Risk sections of this Final Work Plan document, the Registration Review: Preliminary Problem Formulation for Environmenta l Fate and Ecological Risk, Endangered Species, and Drinking Water Ex posure Assessments for Chlorpropham

, dated November 4, 2010, the Followup to EFED’s Response to Comments on Chlorpropham: Outstanding Data Gaps , dated May 26, 2011, and the Chlorpropham. Human-Health Assessment Scoping Docume nt in Support of Registration Review, dated November 2, 2010.

Guideline

Number Data Needs Test

Material Estimated

Timeframe (Measured in

Months from DCI Receipt)

REGISTRATION REVIEW DCI STUDIES

835.1230 Sediment and soil absorption/desorption for parent and degradates TGAI 1 12

835.1240 Soil Column Leaching TEP 2 12

835.4100 Aerobic Soil Metabolism TGAI 24

835.6100 Environmental chemistry method and associated independent laboratory validation for soil 3 TGAI 12

835.6200 Environmental chemistry method and associated independent laboratory validation for water 3 TGAI 12

850.1300 Daphnid Chronic Toxicity TGAI 12

850.1400 Fish Early-Life Stage Toxicity, freshwater TGAI 12
850.2100 Avian Acute Oral Toxicity, passerine TGAI 12
850.2300 Avian Reproduction TGAI 24

850.4100 Nontarget Area Phyotoxicity Tier II, Seedling Emergence 4 TEP 12

850.4150 Nontarget Area Phyotoxicity Tier II, Vegetative Vigor 4 TEP 12

850.4400 Nontarget Area Phyotoxicity Tier II, Aquatic Plant Growth (Vascular plants) 4 TEP 12

850.5400 Nontarget Area Phyotoxicity Tier II, Aquativ Plant Growth (Algal Plants) 4 TGAI or 12

1 Technical Grade Active Ingredient.

2 Typical End use Product.

3 See footnote 7 of 40 CFR 158.1300. EPA will require only the environmental chemistry analytical method portion of GLNs 835.6100 ,Terrestrial field dissipation and 835.6200, Aquatic field dissipation.

4 A Tier II study will be required. The DCI to be issued will provide that a Tier I plant study may be conducted in lieu of a Tier II study with the understandi ng that any adverse effects observed by the Tier I study would necessitate conduct and submission of a Tier II study as well.12 Guideline

Number Data Needs Test

Material Estimated

Timeframe (Measured in

Months from DCI Receipt)

TEP
870.3465 90-Day Inhalation Toxicity 5 TGAI 24
870.6200 Acute and Subchronic Neurotoxicity TGAI 12
870.7800 Immunotoxicity TGAI 12

OUTSTANDING DATA FROM GDCI-018301-17113

171-4d Residue analytical method - animal 12
171-4j Magnitude of residue - meat/milk/poultry/egg 18

5 While the inhalation guideline calls for a 90-day study dura tion, a 28-day study duration will satisfy the Agency’s inhalation exposure data needs.