Docket Number EPA-HQ-OPP-2015-0568 

www.regulations.gov 

Ziram Final Work Plan 

Registration Review 

Case Number 8001 

March 2015 

Approved by: 

Date: 

Yu-T g Guilaran, P.E. 

Dire or 

Pesticide Re-evaluation Division 

·- Steve Knizner 

Director 

Antimicrobials Division 
INTRODUCTION 

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

the registration review of ziram. This work plan addresses public comments received concerning 

the Preliminary Work Plan (PWP), which was posted in the ziram registration review docket 

(EPA-HQ-OPP-2015-0568). Ziram has both conventional pesticide uses and antimicrobial uses. 

As a conventional fungicide, ziram is registered for use on various fruits, nuts, and vegetables, 

including almond, apple, apricot, peach, pear, pecan, and tomato. Ziram is also registered for use 

in non-agricultural areas, including Christmas tree plantations, conifers, and ornamentals. As an 

antimicrobial, ziram is also registered as a mold inhibitor, preservative, and short-term spoilage 

protectant in the following products: latex paint, paper and paperboard, paper coatings, water 

reduced industrial materials, adhesives, industrial yarns and fabrics, and dried films. Ferbam 

(PC code 034801 , a related dithiocarbamate) and ziram have a common degradate- thiram (PC 

code 079801 ). Ferbam and thiram also have pesticidal uses and EPA is conducting separate, 

concurrent, registration reviews for ferbam, thiram, and ziram. 

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 timeline for ziram. Lastly, there is a discussion of next steps. 

UPDATES SINCE THE PWP WAS ISSUED 

There have been no additional updates on ziram since the PWP. 

SUMMARY OF COMMENTS AND AGENCY RESPONSES 

During the 60-day public comment period for the ziram PWP, which opened on October 2, 2015 

and closed on December 1, 2015, the Agency received four public comments. Two comments 

came from VJP Consulting on behalf of the Ziram Task Force and Taminco US Inc., a technical 

registrant. The other comments came from the Center for Biological Diversity (CBD) and the 

San Francisco Bay Regional Water Quality Control Board. 

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

2 
The Ziram Task Force asked the Agency to reconsider the need for pollinator studies, as ziram 

exhibits very low toxicity to honeybees. Taminco US Inc. stated that it intends to fully 

participate in the registration review process for ziram, and will provide relevant information if 

needed. CBD commented on EPA's obligations under the Endangered Species Act (ESA). The 

San Francisco Bay Regional Water Quality Control Board requested that EPA consider zinc, a 

degradate released from ziram in water, in its review. The Board argued that zinc can be 

released in urban runoff, and there are Total Maximum Daily Loads (TMDLs) for zinc. The 

comments did not result in changes to the agency's planned data requirements, risk assessments, 

or registration review timeline. 

In the PWP, EPA also solicited comments on the specific topics of environmental justice and 

trade irritants, but no comments or information were received on those issues. 

Public comments, and EPA's responses in their entirety are located in the docket, EPA-HQ-OPP20 15-0568. Summarized public comments and Agency responses related to the anticipated 

ecological risk assessment or data needs are in the Ziram: Response to Comments on the EFED 

Problem Formulation for Registration Review. Summarized below are public comments that 

addressed the anticipated registration review data needs, risk assessments, or timeline, or are of a 

broader regulatory nature. 

Comments submitted by the Ziram Task Force in EPA-HQ-OPP-2015-0568-0012. 

1. Comment: VJP Consulting, Inc, on behalf of the Ziram Task Force, requested that EPA 

reconsider the need for additional pollinator studies for ziram, since existing data indicates very 

low toxicity to honeybees. In addition, there are no reported adverse incidents involving ziram 

and bees. 

Response: EPA thanks the Ziram Task Force for their comments. At this time, the full suite of 

Tier 1 honeybee data are still needed for ziram in order to assess the need for higher tier 

honeybee testing. In accordance with EPA's 2014 guidance for Assessing Pesticide Risk to Bees 

(available at 

http://www.epa.gov/pesticides/science/efed/policy guidance/team authors/terrestrial biology te 

ch team/guidanceassessingpesticiderisk2bees.pdf), EPA will consider waiving Tier 2 and Tier 3 

honeybee testing for ziram once it has received Tier 1 honeybee data, and has completed Tier 1 

pollinator screening. The Ziram Task Force is not expected to conduct Tier 2 or Tier 3 honeybee 

testing for ziram until a determination has been made by EPA that Tier 2 and Tier 3 honeybee 

data are needed. 

3 
Comments submitted by CBD in EPA-HQ-OPP-2015-0568-0010. 

2. Comment: CBD 's comments focus on the EPA 's duty to consult with the U.S. Fish and 

Wildlife Service and the National Marine Fisheries Service (the Services) on the registration 

review of ziram in accordance with ESA. CBD 's comments mention developing endangered 

species risk assessments, and evaluation of effects on endangered and threatened (listed) species, 

and their designated critical habitat. 

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

opening for ziram 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 ofthe April2013 National Academy of Sciences (NAS) report. EPA will 

address concerns specific to ziram in connection with the development of its final registration 

review decision for ziram. 

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 NAS report2 

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 April 

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 April2013 Report"3, 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 formulation supporting this FWP for ziram 

does 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 

2 http://www.nap.edu/catalog.php?record_id=18344 

3 http:/ /www.epa.gov/espp/20 13/nas.html 

4 
ecological problem formulation document for ziram, EPA described the screening-level risk 

assessment to determine the potential effects of ziram 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 ziram. 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 ziram will describe the level of ESA analysis completed 

for this particular registration review case. Once the agencies have fully developed and 

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

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

as part of completing this registration review. 

Comments submitted by the San Francisco Bay Regional Water Quality Control Board in 

EPA-HQ-OPP-2015-0568-0011. 

3. Comment: The San Francisco Bay Regional Water Quality Control Board noted that ziram is 

used in many urban products such as paint, and degrades rapidly in water, releasing zinc. Use of 

ziram-containing products could leach zinc into urban runoff. The Board requested that EPA 

consider zinc as a de gradate in its review, and update its procedure for identifying whether a 

pesticide is a cause of water quality impairment by: 1) reviewing all §303(d) listings, not just 

pesticide listings, and 2) include all degradates and metals in the pesticide. 

Response: EPA appreciates the Water Board's comment. EPA routinely assesses all pesticide 

degradates of concern and will continue to include degradates in its process for identifying if a 

pesticide is a cause of water quality impairment. Zinc, however, was not identified as a 

degradate of concern for ziram. Levels of zinc that can form in the environment from 

applications of ziram are negligible relative to background levels. When the de gradate of 

concern is a metal, EPA will focus on metal-impaired waters within the use areas ofthe pesticide 

active ingredient. Land cover data will be used to indicate if an ingredient's use areas is within 

the watershed. The relevance of §303d listings and TMDLs for metals outside the active 

ingredient's use area is uncertain due to natural occurrences or non-pesticidal activities such as 

mmmg. 

5 
PLANNED DATA NEEDS 

Table 1 below summarizes the planned data needs for ziram based on the Registration Review: 

Preliminary Problem Formulation for Environmental Fate, Ecological Risk, Endangered Species, 

and Human Health Drinking Water Exposure Assessments for Ziram, Ziram Scoping Document, 

and Ziram: Response to Comments on the EFED Problem Formulation for Registration Review. 

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

Table 1: Planned Data Needs for the Ziram Registration Review 

,. 

Estimated 

Guideline Study Title4 Timeframe 

Number4 Test Material (Months from 

receipt of DCI) 

Anticipated Data Needs for the Parent (Ziram) 

835.31105

•

6

•

7 

835.32205

•

7

•

8 Wastewater treatment plant biodegradation TGAI 12 83 5 .32405,7·9 tests 

835.32805

•

7

•

10 

835.430011 Aerobic aquatic metabolism12 TGAI 24 

850.210013 Avian oral toxicity (passerine species) TGAI 12 

4 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, 2012. 

http://www.regulations.gov/#!documentDetail;D=EP A-HQ-OPPT -2009-0154-0028 5 These data are triggered by the antimicrobial uses of ziram and were also required of sodium and potassium 

dimethyldithiocarbamate salts in a separate registration review case. The data could potentially be bridged 

between any of these three compounds. 6 EPA has a published fmal guideline for this study: http://www.regulations.gov/#!documentDetail;D=EPA-HQOPPT -2009-0152-0003 . 7 The results of the Activated Sludge Respiration Inhibition Test (ASRI), GLN 850.3300, will determine which of 

the four biodegradation tests is/are required. If the ASRI test EC50 is less than or equal to 20 mg/L, then either the 

(i) Biodegradation in Activated Sludge Study, GLN 835.3280 or (ii) Simulation Test- Aerobic Sewage 

Treatment: A. Activated Sludge Units, GLN 835 .3240, or (iii) the Porous Pot Test, GLN 835.3220 is required. If 

the ASRI test EC50 is greater than 20 mg/L, then the registrant must conduct either: (i) Ready Biodegradability or 

(ii) a) Biodegradation in Activated Sludge, or b) Simulation Test- Aerobic Sewage Treatment: A. Activated 

Sludge Units, or c) the Porous Pot Test. If the Ready Biodegradability study is conducted and passes, then no 

further testing is required. If, however, the antimicrobial fails the Ready Biodegradability study, then the (i) 

Biodegradation in Activated Sludge, or (ii) Simulation Test- Aerobic Sewage Treatment: A. Activated Sludge 

Units, or (iii) the Porous Pot study is required. 8 EPA has a published final guideline for this study: http://www.regulations.gov/#!documentDetail;D=EPA-HQOPPT-2009-0 152-0024. 9 EPA has a published final guideline for this study: http://www.regulations.gov/#!documentDetaii;D=EPA-HQOPPT -2009-0152-0034. 10EPA has a published final guideline for this study: http://www.regulations.gov/#!documentDetail;D=EPA-HQOPPT -2009-0152-0036. 11 These data are triggered by both the agricultural and antimicrobial uses of ziram. 12 A study (MRID 46045903) for this requirement is in review. Iffound acceptable, this study will not be required 

for registration review. 13 These data are triggered by the agricultural uses of ziram. 

6 
Table 1: Planned Data Needs for the Ziram Registration Review 

Estimated 

Guideline Study Title4 Timeframe 

Number" Test Material (Months from 

' receipt of DCI) "'- ~ 

850.304013 Field testing for pollinators (tier III) 14 TEP 24 

850.33005

•

7

•

15 

orOECD Modified activated sludge respiration test TGAI 12 

209 

850.450011 •

16 Algal toxicity TEP 12 

850.455011 •

16 Cyanobacteria toxicity TEP 12 

875.120017 Dermal exposure indoor TGAI 24 

875.140017 Inhalation exposure indoor TGAI 24 

875.230018 Indoor surface residue study TGAI 12 

Non- Honeybee adult acute oral toxicity (tier I) TGAI 12 guideline 11 

Non- Honeybee larval acute toxicity (tier I) TGAI 12 guideline 13 

Non- Honeybee adult chronic toxicity (tier I) TGAI 12 guideline 13 

Non- Honeybee larvae chronic toxicity (tier I) TGAI 12 guideline 13 

Non- Semi-field testing for pollinators-tunnel or TEP 24 guideline 13 colony feeding (tier II) 14 

Non- Field trial of residues in pollen and nectar (tier TEP 24 guideline 13 ny4 

Anticipated Data Needs for the Thiram Degradate 

850.135011 Mysid chronic toxicity19 TGAI 12 

850.140011 Estuarine/marine fish early life-stage toxicity TGAI 12 

14 The need for tier II and tier III pollinator studies is contingent upon results of tier I testing and other lines of 

evidence. 15 EPA published draft guidance under guideline 850.6800 and has since published final guidance for this study 

under guideline 850.3300: http://www.regulations.gov/#!documentDetail;D=EPA-HQ-OPPT-2009-0 154-0021. 

OECD Test Guideline 209 can also be used as guidance for this study, available online at http://www.oecdilibrary.org/content/book/9789264070080-en. 

16 In a Federal Register Notice dated June 27, 2012, EPA split the Public Draft OPPTS 850.5400 test guideline into 

two test guidelines: OCSPP 850.4500 and OCSPP 850.4550. See "Final Test Guidelines; OCSPP 850 Series; 

Notice of Availability" 77 FR 38282, June 27, 2012. http://www.regulations.gov/#!documentDetail;D=EPA-HQOPPT -2009-0154-0028. 17 These anticipated data are triggered by the antimicrobial uses of ziram. The indoor exposure studies are needed to 

evaluate occupational handler exposures for: (I) mixing/loading of ziram powder for paint preservation and (2) 

brush/roller and air less sprayer application of preserved paints. 18 These anticipated data are triggered by the antimicrobial uses ofziram. The indoor surface residue study is needed 

to evaluate dermal and incidental oral exposures to ziram treated textiles that are used to manufacture apparel or 

household items such as towels and blankets. 

19 These studies also appear in the thiram problem formulation, but are also deemed important for the risk 

assessment of ziram. 

7 
Table 1: Planned Data Needs for the Ziram Registration Review 

Estimated 

Guideline Study Title4 Timeframe 

Number' Test Material (Months from 

receipt ofDCI) I 

Outstanding Data Requirements from GDCI-034805-2451320 

850.4100 Terrestrial plant toxicity--seedling emergence TEP 12 

850.4150 Terrestrial plant toxicity--vegetative vigor TEP 12 

860.1500 Crop field trials (blackberry)21 TEP 24 

860.1500 Crop field trials (tomato) TEP 24 

TGAI = techmcal grade active ingredient; TEP = typ1cal end-use product; 

20 The studies listed in this section were previously required through a generic data call-in issued in November 2014 

and are still outstanding. These studies will not be included in the anticipated Registration Review DCI because 

they are already required through the earlier DCI. 

21 The tolerance for use ofziram on blackberry has expired. EPA will work with registrants to remove blackberry 

use from the ziram labels. When blackberry use is removed from all ziram labels, crop field trial data on 

blackberry will no longer be required. 

8 
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 ziram. For human health, EPA will 

conduct revised dietary, residential, and occupational risk assessments during registration 

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

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. 

Table 2 below summarizes the planned registration review risk assessments for ziram. The 

planned assessments for ziram have not changed from what was included in the PWP. 

9 
Table 2: Planned Risk Assessments for the Ziram Registration Review 

Type of Risk Assessment Conduct? Notes 

Ecological and Environmental Fate 

Comprehensive ecological y A comprehensive ecological risk assessment will be 

(species to be assessed conducted for ziram. The ziram risk assessment will 

include terrestrial and aquatic also will rely heavily on the combined thirarnlferbam 

organisms), including risk assessment. 

endangered species 

Conventional and Antimicrobial: EPA intends to 

conduct revised ecological risk assessments for both 

conventional and antimicrobial uses of ziram. 

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

updates ziram, see page 17 ofthe Problem Formulation. 

Human Health 

Dietary 

Food y Conventional: Acute and chronic dietary risk 

assessments were conducted in 2010 to support a 

tolerance action. Both acute and chronic dietary risks 

were below the Agency's level of concern. EPA 

anticipates conducting a revised dietary assessment to 

Drinking water y incorporate updated models and assumptions and any 

changes to toxicological points of departures or 

drinking water estimates. 

Antimicrobial: The antimicrobial uses of ziram are 

non-food uses. Any dietary exposure from the 

antimicrobial uses of ziram are considered to be 

negligible. 

Occupational 

Handlers (mixers, loaders, y Conventional: EPA anticipates updating occupational 

applicators) exposure and risk assessments based on current 

policies and exposure assessment methodology. 

Antimicrobial: Inhalation exposures for the 

antimicrobial uses may be reevaluated during 

Post -application y registration review to incorporate inhalation toxicity 

data that was submitted since the issuance of the 

RED. 

Residential 

10 
Handlers y Conventional: Conventional uses of ziram are not 

expected to result in residential exposure, therefore, a 

residential assessment is not planned for conventional 

uses during registration review. 

Antimicrobial: Residential exposure is anticipated 

from the antimicrobial uses of ziram. EPA anticipates 

Post -application y conducting a post-application residential assessment 

for the anti-microbial uses during registration review. 

Bystander y Conventional: During registration review, EPA will 

determine if a residential bystander exposure 

assessment is needed. 

Antimicrobial: A bystander exposure assessment is 

not anticipated for the antimicrobial uses of ziram. 

Other 

Aggregate y There are no residential uses associated with the 

conventional uses of ziram. Post-application 

exposures from the antimicrobial industrial yam and 

fabric use(s) may require aggregation with the dietary 

exposures if it is determined that ziram treated yams 

and fabrics are used to manufacture household goods 

and apparel. 

Cumulative N Ziram has not been identified as a member of a 

cumulative group, therefore, no cumulative risk 

assessment is planned. 

Tolerances y Tolerance residue levels for ziram may need to be 

reexamined during registration review to harmonize 

with Codex and Canadian MRLs. 

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

updates ziram, see page 1 0 of the Scoping Document and the 

Ziram: Tier I Review of Human Incidents. 

11 
TIME LINE 

EPA has created the following estimated time line for the completion of the ziram registration 

review in Table 3 below. The projected timeline has been modified since the PWP to include a 

revised date for the close of the public comment period for the docket opening. 

Table 3: Projected Ziram Registration Review Timeline 

Activities Estimated Date 

Opening the Docket 

Open Docket and 60-day Public Comment Period September 20 15--completed 

Close Public Comment December 20 15--completed 

Case Development 

Final Work Plan March 20 16--completed 

Issue DCI May-July 2016 

Data Submission May-July 2018 

60-day Public Comment Period for Draft Risk September-November 2019 

Assessments22 

Registration Review Decision 

60-day Public Comment Period for Proposed June-September 2020 

Registration Review Decision 

Registration Review Decision and Begin Post-Decision January-March 2021 

Follow-up 

Total (years) 6 

NEXT STEPS 

As noted previously, the Agency plans to require several environmental fate, ecological effects, 

and human health studies for ziram through a Data Call-In Notice, expected to be issued in the 

spring/summer of2016. 

22 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. 

12