Docket Numbers: Ferbam EPA-HQ-OPP-2015-0567 

Thiram EPA-HQ-OPP-20 15-0433 

www.regulations.gov 

Ferbam and Thiram Final Work Plan 

Registration Review 

Ferbam Case Number 8000 

Thiram Case Number 0122 

March 2016 

Approved by: 

Yu-~aran Director 

Pesticide Re-evaluation Division 

Date: 0}tSltS 
INTRODUCTION 

This is the Environmental Protection Agency's (EPA or the Agency) Final Work Plan (FWP) for 

the registration review of ferbam and thiram. This work plan addresses public comments 

received concerning the Preliminary Work Plan (PWP), which was posted in the ferbam (EPAHQ-OPP-20 15-0567) and thiram registration review dockets (EPA-HQ-OPP-20 15-0433). 

Ferbam and thiram are dimethyldithiocarbamate fungicides. EPA will assess ferbam and thiram 

together during registration review, because ferbam rapidly degrades to the more persistent 

thiram. Ferbam is primarily registered for use on grapefruits and oranges in Florida to control 

scab disease. It is also used to control anthracnose disease on mangoes in Florida (as a special 

local need registration). Other agricultural use sites for ferbam include: apples, citrus, 

cranberries, pears, peaches, and nectarines. There are no non-agricultural use sites for ferbam. 

Thiram is registered for use on apples, strawberries, peaches, and nectarines. A tolerance without 

US registration is established for avocado, and banana/plantain use. It is also registered as a seed 

treatment (non-food use). Thiram is labeled for use on non-bearing trees, shrubs, nursery stock, 

and ornamentals as an animal repellent to protect crops from damage by rabbits, rodents, and 

deer. Thiram is also registered for non-agricultural use on golf course turf tees and greens. 

The Agency is implementing the registration review program pursuant to Section 3(g) of the 

Federal Insecticide, Fungicide, 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. Changes in science, public policy, and pesticide use practices occur over time. 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. 

The public phase of registration review begins when the initial docket is opened for each case. 

Information on this program is provided on the Agency's website. 1 

The FWP begins with any updates since the PWP was issued. Next is a summary of substantive 

comments received during the public comment period for the PWP concerning anticipated data 

needs, expected risk assessments, or the estimated timeline identified in the PWP, and a 

summary of the Agency's responses to those comments. This section is followed by registration 

review planned data needs, risk assessments expected to be conducted, and the projected 

registration review timelines for ferbam and thiram. Lastly, there is a discussion of next steps. 

UPDATES SINCE THE PWP WAS ISSUED 

The PWP for ferbam and thiram indicated that thiram is registered for use on avocado in the U.S. 

During the 60-day public comment period, the Thiram Task Force commented that the tolerance 

for avocado is for imported avocadoes only. There are no U.S. registrations for thiram on 

avocado. The FWP reflects this correction. 

1 http://www2.epa.gov/pesticide-reevaluation 

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SUMMARY OF COMMENTS AND AGENCY RESPONSES 

During the 60-day public comment period for the ferbam and thiram PWP, which opened on 

October 2, 2015 and closed on December I, 2015 , the Agency received two public comments for 

ferbam, and 4 public comments for thiram. Public comments for ferbam were submitted from 

VJP Consulting on behalf ofTaminco US Inc. , a registrant, and the Center for Biological 

Diversity (CBD). VJP Consulting noted that Taminco did not receive a data call-in (DCI) for 

ferbam for crop field trials in apples, but Taminco plans to bridge to apple trials conducted with 

both thiram and ziram supported by comparative peach trials with ferbam, ziram, and thiram. 

CBD commented on EPA's duty to complete threatened and endangered (listed) species 

assessment and consult with the U.S. Fish and Wildlife Service (FWS), and the National Marine 

Fisheries Service (NMFS) (together, the Services), on ferbam. 

Public comments for thiram were submitted from the Thiram Task Force, the FIFRA Endangered 

Species Task Force (FESTF), the Physicians Committee for Responsible Medicine (PCRM), and 

from CBD. The comments from the Thiram Task Force addressed data requirements, and the 

import tolerance for avocado. The comment from FESTF identified MacDermid Agricultural 

Solutions as a FESTF member, which is entitled to rely on FESTF data for endangered species 

risk assessments. PCRM recommends using the OECD Test Guideline 223 (TG223) instead of 

EPA Guideline 850.2100 for the acute avian oral sequential dose study, in the interest of 

reducing the numbers of animals tested. CBD's comments focused on EPA's duty to consult 

with the Services on the registration review of thiram in accordance with the Endangered Species 

Act (ESA). None of the comments addressed the timeline described in the PWP, or the planned 

ecological and human health risk assessments. In the PWP, EPA also solicited comments on the 

specific topics of environmental justice, water quality concerns, and trade irritants, but no 

comments or information were received on those issues. 

This section summarizes the submitted public comments, and provides the Agency's response. 

Public comments in their entirety are located in the dockets EPA-HQ-OPP-20 15-0567 (ferbam) 

and EPA-HQ-OPP-20 15-0433 (thiram). For a more detailed response, please refer to the 

documents titled Thiram: Response to Comments on the EFED Problem Formulation for 

Registration Review and Thiram: Response to Comments on the Human Health Risk Scoping 

Document in Support of Registration Review, which are also located in the thiram docket. 

Ferbam Comments: 

Comments submitted by VJP Consulting, Inc in EPA-HQ-OPP-2015-0567-0009. 

1. Comment: VJP Consulting, on behalf ofTaminco US Inc., stated that they intend to fully 

participate in the registration review process. They also noted that they were not in receipt of 

a DC! for fer bam requiring crop field trials in apples, but plan to bridge to existing peach 

data for ziram and thiram. 

Response: EPA is pleased that Taminco intends to fully participate in the registration review 

process. EPA issued a generic data call-in (GDCI) in support of the reregistration of ferbam 

in May 2008 (GDCI-034801-26275). Taminco was listed as a registrant, and guideline 

860.1500-crop field trials (apple) was listed as a data requirement in this DCI. Crop field 

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trials for apple were also noted as requirements in past GDCis issued in 1993 (GDCI-03480 1-

17316) and in 1991 (GDCI-03480 1-16873). Since this requirement was noted in past DC Is, 

EPA will not require crop field trials in apples as part of the registration review GDCI. 

Taminco's plan to bridge to existing peach field trial data for ziram and thiram to fulfill this 

requirement is acceptable to EPA. Taminco should cite/submit the existing peach field trial 

data as soon as possible. 

Thiram Comments: 

Comments submitted by the Thiram Task Force in EPA-HQ-OPP-201 5-0433-0012. 

1. Comment: The Thiram Task Force recognizes the need for many of the studies listed as 

anticipated data needs for the Thiram Registration Review; however, there are a few studies 

that the Thiram Task Force would like the Agency to reconsider. A turf transferable residue 

(JTR) study is not needed. 

Response: At the registrant's request, EPA has reconsidered the requirement for the TTR 

study, and has confirmed that the data are necessary. In accordance with the updated (2007) 

Part 15 8 data requirements of the 40 CFR, TTR data are required for all turf uses that could 

result in post-application exposure to treated turf. The guidance for waiving these data was 

developed considering the conservative nature of the standard/default residue transfer values. 

The waiver criterion, requiring that MOEs are 10 times greater than the level of concern 

(LOC), was based on the data used to develop these standard/default residue transfer values. 

In the case of thiram, the LOC is 1 00; therefore, all MOEs would need to be 1,000 or above 

in order for the TTR data waiver to be granted. The assessment of thiram' s turf use (golf 

course) yields an MOE of 850 for children 6 to <11 years old, which does not meet the 

criterion; therefore, the waiver may not be granted. 

2. Comment: The Thiram Task Force believes that the Agency should reconsider the need for 

the pollinator studies identified in the P WP. The EPA categorizes pesticides as "toxic to 

bees" if the acute contact LD5o is < 11 11glbee. Available data indicate that the contact LD5o 

for thiram is 7 3. 72 11glbee and was considered by the Agency to be practically nontoxic to 

bees. Additionally, it is not believed that there have been any adverse incidents involving 

thiram and bees. 

Response: Although thiram is categorized as practically non-toxic to adult honey bees via 

acute contact exposure, there is considerable uncertainty regarding the potential effects of the 

compound on honey bee larval development and survival, as well as potential for chronic 

effects. Additional data on pollinators are needed to fully characterize the risk associated 

with thiram use to all developmental stages of honey bees, as sensitivity may vary according 

to life-stage (adult vs. eggs, larvae, and pupae), length of exposure (acute vs. chronic), and 

route of exposure (contact vs. oral). As indicated in EPA guidance issued in 20142, assessing 

risks to bees involves a battery of laboratory-based studies (Tier 1 ). Depending on the 

2 USEPA. 2014. Guidance for Assessing Pesticide Risks to Bees. Office of Pesticide Programs United States 

Environmental Protection Agency, Health Canada Pest Management Regulatory Agency, California Department of 

Pesticide Regulation. June 19, 2014. Available at: http://www.epa.gov/pollinator-protection/pollinator-riskassessment-guidance 

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outcome of those studies, semi-fie ld and full-field studies (Tier II and Tier III) involving 

whole bee colonies may be required to refine the understanding of risk to the whole colony. 

An absence of reported incidents does not necessarily equate to an absence of incidents given 

the nature of incident reporting. Incidents that do not involve acute mortality events can be 

difficult to identify and are very rarely reported. 

3. Comment: The members of the Thiram Task Force hold segmented labels for foliar and seed 

treatment uses. It would be helpful to the Task Force if the FWP could designate which data 

requirements are for foliar uses, for seed treatments, and for both. 

Response: OCSPP 850.4150, Vegetative Vigor, is applicable to foliar uses only. All other 

requested ecotoxicity studies apply to both fo liar uses and seed treatments. 

Comments submitted by FESTF in EPA-HQ-OPP-2015-0433-0010. 

4. Comment: MacDermid Agricultural Solutions, Inc., a technical registrant, is a FESTF 

member and is entitled to rely on the FESTF data. 

Response: The Agency thanks FESTF for its comment, and will consider the FESTF data 

during the thiram registration review. 

Comments submitted by the PCRM in EPA-HQ-OPP-2015-0433-0013. 

5. Comment: PCRM has identified acute avian oral toxicity data for a passerine species via 

Extoxnet (http://extoxnet. or st. edu/pips/thiram. htm). The stated LD5o is >I 00 mg/kg in redwinged blackbirds. If additional data are needed, PCRM recommends using the OECD Test 

Guideline 223 (TG223) instead of EPA Guideline 850.2IOO in the interest of reducing the 

numbers of animals used. 

Response: EPA will review the red-winged blackbird study referenced by PCRM if it is 

submitted to the Agency for that purpose. However, EPA notes that a limit dose of 100 

mg/kg is unlikely to be sufficient for risk assessment. EPA will accept TG223 studies in 

place of850.2100 studies under the conditions laid out in EPA's 2011 Guidance for 

Classifying Studies Conducted Using the OECD Test Guideline 223 (TG223) (Acute Avian 

Oral Sequential Dose Study) (http:/ /www.epa.gov/pesticide-science-and-assessing-pesticiderisks/guidance-classifying-studies-conducted-using-oecd). 

Comments that Address Both Ferbam and Thiram: 

Comments submitted by CBD in EPA-HQ-OPP-2015-0567-0008 (ferbam docket), and in 

EPA-HQ-OPP-2015-0433-0011 (thiram docket). 

1. Comment: CBD 's comments focus on the EPA 's duty to consult with the Services on the 

registration review of fer bam and thiram in accordance with the ESA. CBD 's comments 

mention developing listed species risk assessments, and evaluation of effects on listed species, 

and their designated critical habitat. 

5 
Response: EPA has reviewed the comments from CBD on the registration review docket 

openings for fer bam and thiram, and plans to address many of the concerns raised by CBD as 

part of the implementation plan for assessing the risks of pesticides to listed species based on 

the recommendations of the April 2013 National Academy of Sciences (NAS) report. EPA 

will address concerns specific to ferbam and thiram in connection with the development of the 

final registration review decisions for ferbam and thiram. 

In November 2013, the EPA, along with the Services and the USDA, released a summary of 

their joint Interim Approaches for assessing risks to listed species from pesticides. The 

Interim Approaches were developed jointly by the agencies in response to the NAS report 

recommendations, and reflect a common approach to risk assessment shared by the agencies 

as a way of addressing scientific differences between the EPA and the Services. The N AS 

report outlines recommendations on specific scientific and technical issues related to the 

development of pesticide risk assessments that EPA and the Services must conduct in 

connection with their obligations under the ESA and FIFRA. 

The joint Interim Approaches were released prior to a stakeholder workshop held on 

November 15, 2013. In addition, the EPA presented the joint Interim Approaches at the 

December 2013 Pesticide Program Dialogue Committee (PPDC) and State-FIFRA Issues 

Research and Evaluation Group (SFIREG) meetings. The agencies also held stakeholder 

workshops in April2014 and October 2014, and in April2015, allowing additional 

opportunities for stakeholders to comment on the Interim Approaches. Additional workshops 

are planned to enhance stakeholder involvement. As part of a phased, iterative process for 

developing the Interim Approaches, the agencies will also consider public comments on the 

Interim Approaches in connection with the development of upcoming registration review 

decisions. The details of the joint Interim Approaches are contained in the white paper 

"Interim Approaches for National-Level Pesticide Endangered Species Act Assessments 

Based on the Recommendations of the National Academy of Sciences April 2013 Report," 

dated November 1, 2013. 

Given that the agencies are continuing to develop and work toward implementation of the 

Interim Approaches to assess the potential risks of pesticides to listed species and their 

designated critical habitat, the ecological problem formulations supporting the FWPs for 

ferbam and thiram do not describe the specific ESA analysis, including effects determinations 

for specific listed species or designated critical habitat, to be conducted during registration 

review. In the ecological problem formulation documents for fer bam and thiram, EPA 

described the screening-level risk assessment to determine the potential effects offerbam and 

thiram on all taxa of non-target wildlife and plants, which will assume that listed species and 

their designated critical habitats may be present in the vicinity of the application of ferbam 

and thiram. This screening-level assessment will allow EPA to focus its future evaluations on 

the types of species where the potential for effects exists once the scientific methods being 

developed by the agencies have been fully vetted. While the agencies continue to develop a 

common method for ESA analysis, the planned screening-level risk assessment for the 

registration review of fer bam and thiram will describe the level of ESA analysis completed for 

these particular registration review cases. Once the agencies have fully developed and 

implemented the scientific methods necessary to complete risk assessments for listed species 

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and their designated critical habitats, these methods will be applied to subsequent analyses for 

ferbam and thiram as part of completing these registration reviews. 

PLANNED DATA NEEDS 

Table 1 below summarizes the planned data needs for thiram. Since ferbam degrades to thiram 

in the environment, EPA intends to bridge data from thiram to assess ferbam. Therefore, there 

are no anticipated data needs for ferbam for registration review per se. The planned data needs 

are based on the Registration Review: Preliminary Problem Formulation for Environmental 

Fate, Ecological Risk, Endangered Species, and Human Health Drinking Water Exposure 

Assessments for Ferbam and Thiram, the Ferbam Scoping Document, and the Thiram. Human 

Health Assessment Scoping Document in Support of Registration Review. The planned data 

needs have not changed from what was included in the PWP. 

Table 1: Planned Data Needs for the Thiram Registration Review 

Estimated 

Guideline Study Title3 Timeframe 

Number' Test Material (Months from 

receipt of DCI) 

" 

Anticipated Data Needs for Thiram 

875.2100 Turf transferable residue study TGAI 12 

870.3465 28-day inhalation study TGAl 24 

850.1350 Mysid chronic toxicity TGAl 12 

850.1400 Estuarine/marine fish early-life stage toxicity TGAl 12 

Algal toxicity (fresh water diatom Navicula 

850.4500 pelliculosa and marine diatom Skeletonema TGAl 12 

cos tatum) 

850.4550 Cyanobacteria toxicity TGAI 12 

850.2100 Avian acute toxicity (passerine species) TGAI 12 

850.4100 Seedling emergence TGAl 12 

850.4150 Vegetative Vigor TGAl 12 

Non- Honey bee adult acute oral toxicity (Tier I) TGAI 12 guideline4 

Non- Honey bee larvae acute toxicity (Tier I) TGAl 12 guideline4 

Non- Honey bee adult chronic oral toxicity (Tier I) TGAl 12 guideline4 

Non- Honey bee larvae chronic toxicity (Tier I) TGAl 12 guideline4 

3 On June 27, 2012, EPA announced certain revisions in harmonized guideline series 850 - Ecological Effects Tests 

- including renumbering and other designations or changes for some guideline studies. See "Final Test 

Guidelines; OCSPP 850 Series; Notice of Availability" 77 FR 38282, June 27, 201 2. 

http://www.regulations.gov/#! documentDetaii ;D=EPA-HQ-OPPT -2009-0 154-0028 4 Tier 2 and 3 studies are conditional on the outcome of the screening-level assessment for terrestrial invertebrates 

based on Tier I studies of individual bees. 

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Table 1: Planned Data Needs for the Thiram Registration Review 

Estimated 

Guideline Study Title3 Timeframe 

Numberl Test Material (Months from 

receipt ofDCI) 

Non- Semi-field testing for pollinators (tunnel or TEP 24 

guideline4 colony feeding studies (Tier 2) 

Non- Field trial of residues in pollen and nectar (Tier 2) TEP 24 

guideline4 

850.30404 Field testing for pollinators (Tier 3) TEP 24 

Outstanding Data Requirements from GDCI-034801-26275 (Ferbam) 

860.15005 Crop field trials (app le) TEP 24 

TGAI = techmcal grade active mgredient; TEP = typical end-use product 

RISK ASSESSMENTS FOR REGISTRATION REVIEW 

During registration review, the Agency will conduct a comprehensive ecological risk assessment, 

including an endangered species assessment, for all uses of ferbam and thiram. For human 

health, EPA will conduct revised dietary and occupational risk assessments for ferbam. EPA 

will conduct revised dietary, residential, and occupational risk assessments for thiram during 

registration review. If toxicological endpoints or points of departure are revised based on the 

data that are anticipated to be required for registration review, they will be considered in the new 

assessments, as well as any changes to the standard operating procedures or default exposure 

assumptions. 

Tables 2 and 3 below summarize the planned registration review risk assessments based on the 

combined ferbam/thiram EFED Problem Formulation, and the ferbam and thiram HED Scoping 

Documents. The planned assessments have not changed from what was included in the PWP. 

Table 2: Planned Risk Assessments for the Ferbam Registration Review 

Type of Risk Assessment Conduct? Notes 

Ecological and Environmental Fate 

Comprehensive ecological y Thiram, a major transformation product of 

(species to be assessed ferbam, will be assessed with ferbam. 

include terrestrial and 

aquatic organisms), 

including endangered 

species 

Incidents Will check for For a discussion of reported ecological 

updates incidents for ferbam, see page 21 of the 

Problem Formulation. 

Human Health 

5 It is possible to bridge crop field trial data for apple for ferbam, ziram, and thiram. 

8 
Dietary 

Food y The RED acute and chronic dietary risk 

Drinking water y assessments did not identify risks of concern. 

A new dietary risk assessment may need to be 

conducted if there are changes to toxicological 

endpoints or safety factors or changes to 

estimated drinking water concentrations. 

Occupational 

Handlers (mixers, loaders, y The revised RED occupational risk assessment 

applicators) identified post-application risks of concern. A 

Post -application y new occupational handler and post-application 

risk assessment may be needed to incorporate 

changes to toxicological points of departures or 

changes to risk assessment policy. 

Residential 

Handlers N There are no registered residential uses of 

Post -application N ferbam, therefore, a residential exposure 

assessment is not needed for registration 

revtew. 

Bystander y During registration review, the agency will 

determine if a residential bystander assessment 

is needed for ferbam. 

Other 

Aggregate N Evaluates the combined risk from dietary and 

residential exposures. Since there are no 

residential uses for ferbam, an aggregate risk 

assessment includes only dietary exposure. 

Cumulative N Ferbam has not been identified as a member of 

a cumulative group with a common mechanism 

oftoxicity and therefore, no cumulative 

assessment is planned. 

Tolerances y During registration review, the Agency 

anticipates updating the tolerance expression 

residue levels to determine if further 

harmonization can be achieved. The agency 

may reevaluate the tolerance levels for ferbam 

if new field trial data is received. The Agency 

may also consider converting the tolerances for 

the dimethyl dithiocarbamates (thiram, ziram, 

and ferbam) and the ethylene bisdithiocarbamates (EBDCs) to being expressed 

as carbon disulfide equivalents. 

Incidents Will check for For a discussion of reported human incidents 

updates for fer bam, see page 10 of the Scoping 

Document and the Ferbam: Tier I (Scoping) 

Review of Human Incidents and Epidemiology. 

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Table 3: Planned Risk Assessments for the Thiram Registration Review 

Type of Risk Assessment Conduct? Notes 

Ecological and Environmental Fate 

Comprehensive ecological y Thiram is a major transformation product of ferbam, 

(species to be assessed EPA intends to assess thiram with ferbam. 

include terrestrial and aquatic 

organisms), including 

endangered species 

Incidents Will check for For a discussion of reported ecological incidents for 

updates thiram, see page 21 of the Problem Formulation. 

Human Health 

Dietary 

Food y A new dietary assessment is anticipated for 

Drinking water y registration review to incorporate any changes to 

toxicological PODs or uncertainty factors (UFs), 

methodologies or updated drinking water estimates. 

Occupational 

Handlers (mixers, loaders, y The Agency anticipates updating the occupational risk 

applicators) assessment during registration review to incorporate 

Post-application y any revised toxicological PODs, current policies or 

exposure assessment methodologies. 

Residential 

Handlers y The Agency anticipates revising the residential 

Post -application y exposure risk assessment during registration review to 

incorporate the required chemical-specific TTR data. 

The Agency will evaluate the need for spray drift and 

volatilization risk assessments for thiram during 

registration review. 

Other 

Aggregate y Evaluates the combined risk from dietary and 

residential exposures. A revised aggregate exposure 

risk assessment may be necessary during registration 

review to incorporate any potential changes to the 

dietary or residential assessments. 

Cumulative N EPA has not made a common mechanism of toxicity 

finding as to thiram and any other substances and 

thiram does not appear to produce a toxic metabolite 

produced by other substances. 

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Tolerances y During registration review, the Agency anticipates 

examining the tolerance residue levels to determine if 

further harmonization can be achieved. The Agency 

may also consider converting the tolerances for the 

dimethyl dithiocarbamates (thiram, ziram, and 

ferbam) and the ethylene bis-dithiocarbamates 

(EBDCs) to being expressed as carbon disulfide 

equivalents. 

Incidents Will check for For a discussion of reported human incidents for 

updates thiram, see page 11 of the Scoping Document and the 

Thiram: Tier I Review ofHuman Incidents and 

Epidemiology. 

TIME LINE 

EPA has created the following estimated timeline for the completion of the ferbam and thiram 

registration review in Table 4 below. The projected timeline has not changed since the PWP. 

Table 4: Projected Ferbam and Thiram Registration Review Timeline 

Activities Estimated Date 

Opening the Docket 

Open Docket and 60-day Public Comment Period October 2015 - Completed 

Close Public Comment December 2015 - Completed 

Case Development 

Final Work Plan March 2016 - Completed 

Issue DCI6 2016 - April- June 

Data Submission 2018 - April- June 

60-day Public Comment Period for Draft Risk 

Assessments 7 2019 - Oct- Dec 

Registration Review Decision 

60-day Public Comment Period for Proposed 2020 - July - Sept. 

Registration Review Decision 

Registration Review Decision and Begin Post-Decision 2021 

Follow-up 

Total (years) 6 

6 There are no data requirements for ferbam ; therefore, a DCI will not be issued. However, since data will be 

bridged from thiram or ziram to assess ferbam, the three registration review cases are on the same projected 

registration review timeline. 7 The regulations governing Registration Review generally require the Agency to provide a public comment period 

of at least 30 calendar days for draft risk assessments; see 40 CFR Part 155 .53( c). For conventional pesticides, the 

Agency plans to provide a 60 calendar day public comment period generally for draft risk assessments. 

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NEXT STEPS 

As noted previously, the Agency plans to require certain ecological effects and human health 

studies for thiram through a DCI, expected to be issued in spring/summer 2016. 

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