Docket Number; EPA–HQ–OPP–2009–0723 www.regulations.gov

United States Chemi cal Safety June 2010

Environmental Protection and Pollution Prevention Agency (7510P)



# Disodium Cyanodithioimidocarbonate (DCDIC) Final Work Plan Registration Review June 2010Docket Number; EPA-HQ-OPP-2009-0723 www.regulations.gov

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### TABLE OF CONTENTS

Disodium Cyanodithioimidocarbonate ( DCDIC) Registration Review Team......................... 4

I. INTRODUCTION ................................................................................................................ ..... 5

II. COMMENTS RECEIVED ON THE PRELIMINARY WORK PLAN.............................. 5

III. RISK ASSESSMEN T AND DATA NEEDS......................................................................... 6

IV. TIMELINE ................................................................................................................... ......... 13

V. GLOSSARY of TERMS & ABBREVIATIONS.................................................................. 14Docket Number; EPA-HQ-OPP-2009-0723 www.regulations.gov

4 Disodium Cyanodithioimidocarbonate (DCDIC) Registration Review Team

Human Health & Environmental Effects

Nathan Mottl

Srinivas Gowda

Risk Management

Monisha Harris

Lance Wormell

Office of General Counsel Philip RossDocket Number; EPA-HQ-OPP-2009-0723 www.regulations.gov

5 I. INTRODUCTION

This is the Environmental Protection Ag ency’s (EPA or “the Agency”) Final Work Plan (FWP) for the registration revi ew of Disodium Cyanodithioimidocarbonate (DCDIC). The work plan includes the expect ed registration review timeline. The work plan also addresses public comments receiv ed concerning the Preliminary Work Plan (PWP) in the Summary Document which was posted in the DCDIC registration review docket, and any other comments concerning the initial docket postings. The Summary Document provided information on what EP A knows about the pesticide and what additional risk analyses and da ta or information the Agency believes are needed to make a registration review decision.

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 de termine whether it continues to meet the FIFRA standard for registration. Changes in science, public policy and pesticide use practices will occur over time. The registra tion review program is intended to make sure that, as the ability to assess risk evolve s and as policies and practices change, all registered pesticides continue to meet th at statutory standard. The public phase of registration review begins when the initial docket is opened for each case. Information on this program is provided at: http://www.epa.gov/oppsrrd1/registration_review/

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The DCDIC Preliminary Work Plan was published December 16, 2009. The 90-day comment period ended on March 16, 2010. The Preliminary Work Plan document is

available on www.regulations.gov , docket number EPA-HQ-OPP-2009-0723.

II. COMMENTS RECEIVED ON THE PRELIMINARY WORK PLAN

EPA received one comment during the public comment period on the initial docket, described below. In the PWP, EP A also solicited comments on three specific topics: environmental justice; water body impairment; and trad e irritants. No comments or information were received during the public comment period concerning these issues.

During the public comment period, EPA r eceived one comment as described and

discussed below. The comment received duri ng the initial public comment period did not affect the data needs, work plan and timelin e described in the PWP and they remain as they were presented initially in the PWP. Further, this document makes final the work plan for the DCDIC regist ration review process.

Comment: The FIFRA Endangered Species Task Force (FESTF) submitted a comment requesting that any technical regi strant for DCDIC who is not a member of the FESTF (or a company having met its data compensation obligations) be asked to provide a formal offer-to-pay to FESTF for reliance on their data.Docket Number; EPA-HQ-OPP-2009-0723 www.regulations.gov

6 Response: The Agency thanks FESTF for its comment and will consider this information as it conducts the registra tion review and makes its registration

review decisions.

III. RISK ASSESSMENT AND DATA NEEDS

A Reregistration Eligibilit y Decision was completed for DCDIC in September 1994. However, to complete registration revi ew, additional data are anticipated to be

needed to conduct the human health and ecological risk assessments.

Human Health Risk

The hazard and exposure databases and the available risk assessments for DCDIC were examined to determine whether they reflect the current state of the science, changing use patterns, and current policies/re gulations/statutory requirements. Based on its review, the Agency anticipates that addi tional toxicity and expos ure studies will be needed for registration review. The EPA anticip ates that there is potential occupational inhalation and dermal exposure through ope n-pour mixing/loading exposures. The Agency will need to select dermal and inha lation toxicity endpoint s to conduct inhalation and dermal occupational handler risk asse ssments. The Agency believes that risk

assessments are needed to ensure that th e DCDIC registration re view case meets the standards established by FIFRA and FFDCA, as amended by FQPA.

The Agency anticipates needing to conduct a dietary assessment based on indirect dietary exposure. The need for drinking wate r assessment will be determined based on

the environmental assessment. The data, outlined in the anticipated environmental fate data needs, will be useful in determining whether discharged DCDIC resulting from the recirculating cooling tower use can pass thr ough waste-water treatmen t facilities into drinking water or migrate into residential groundwater wells.

The Agency has reached the following conc lusions after reviewing the hazard and exposure databases.

• The Agency believes the existing toxicological data triggers the need for an inhalation and dermal occupational risk assessment from exposure to open-pour mixing/loading systems.

• An inhalation toxicity study is expected to be needed to assess inhalation occupational exposure.

• Dermal and inhalation exposure studies ar e expected to be needed to assess occupational exposure.

• The Agency will need to assess dietary exposures and risks for food use sites (e.g., cane and beet sugar mills) and an indirect food use (e.g., preserved food paperboard).

• Based on the need to assess dietary exposur e, EPA anticipates that there will be a need for additional toxicity studies in or der to characterize the hazards and selectDocket Number; EPA-HQ-OPP-2009-0723 www.regulations.gov

7 an oral toxicological endpoint (e.g., repr oduction and fertility toxicity study and a 90-day oral toxicity study in rodents).

• The Agency expects to require e nvironmental fate data (e.g., ready biodegradability test, photodegradation, etc.) for use in determining if discharged DCDIC resulting from the re-circulati ng cooling tower use can pass through

waste-water treatment facilities into dr inking water or migrate into residential groundwater wells. Therefore, the need fo r a dietary drinking water assessment would be determined upon submission and review of the environmental fate data.

Further information is available in the document titled, “Disodium Cyanodithioimidocarbonate. Human Health Effects Scoping Document for the Registration Review Decision,” dated December 7,2009.

Dietary and Drinking Water Assessment

Dietary Exposure

A dietary exposure risk assessment has not been performed for DCDIC. Because current labels indicate that raw juice and wash water for cane and beet sugar mills could be treated with DCDIC to prevent juice from spoiling and because DCDIC is used in pulp and papermills as a slimicide making it possible for DCDIC to migrate into food exposed to the treated paper , the Agency will need to conduct a dietary assessment.

DCDIC has been cleared for use by the Food and Drug Administration (FDA) for the use in sugar beet and sugar cane m ills under 21 CFR 173.320. FDA limits DCDIC as a chemical for controlling microorganism in cane-sugar and beet-sugar mills to a maximum level of 2.5 ppm in terms of the we ight of the raw cane or raw beet. DCDIC has been cleared for use by the FDA for food contact with food grade paper, paperboard, (21 CFR 176.300), adhesives (21 CFR 175.105) , animal glue (21 CFR 178.3120) and manufacture of paper and paperboard produc ts used in food packaging (21 CFR 181.30).

Drinking Water Exposure

The need for a dietary drinking wate r assessment will be determined upon

submission and review of the environmental fate data expected to be required. DCDIC is primarily used in indoor indus trial use sites (e.g., industrial water purification systems, sugar and cane processing water, and recirc ulating water cooling towers). The current indoor uses of DCDIC are expected to resu lt in minimal residues in drinking water supplied by residential wells or municipal s ources because re-circulating water cooling towers are expected to have infrequent di scharges and the discharges are regulated by NPDES permits. In addition, labels specify th at the industrial wate r purification systems are not intended for use in potable water systems.

However, the need for a dietary drin king water exposure assessment for DCDIC will be determined upon review of environmenta l fate data expected to be required. The

environmental fate data would be useful in determining the likelihood of dischargedDocket Number; EPA-HQ-OPP-2009-0723 www.regulations.gov

8 DCDIC resulting from the re-circulating coo ling tower use passing through waste-water treatment facilities into drinking water or mi grating into residential groundwater wells.

Although the oil well injection use is an outdoor industrial use, EPA expects that

DCDIC would be contained within a well casing when it is used, and that ground water is not normally at risk of contamination under these conditions. Therefore, EPA will not conduct any drinking water assessments for this particular use.

Tolerances

There are no tolerances or exemptions from tolerances for DCDIC. DCDIC is allowed as a secondary direct food additive at a maximum level of 2.5 ppm (expressed as weight of the raw cane or raw beet) for c ontrolling microorganism s in cane-sugar and beet-sugar mills by the Food and Drug Administration (FDA) under 21 CFR 173.320.

DCDIC is used as a slimicide in the manuf acture of food grade pape r and paperboard (21 CFR 176.300), as a component of adhesive s (21 CFR 175.105), in the production of animal glue (21 CFR 178.3120) and in manuf acture of paper and paperboard products used in food packaging (21 CFR 181.30).

It is noted that exemptions and regula tions for food additives under Section 409 of the Federal Food, Drug, and Cosmetic Act ( FFDCA) do not relieve the registrant of meeting the standard under Section 408 as amended by the Food Quality Protection Act (FQPA), when the active ingredie nt is subject to regulation as a food-use pesticide under the Federal Insecticide, Fungicide, and Rode nticide Act (FIFRA). Under Section 408, a determination of safety for residues of a pes ticide that may be in food is required, and as defined in Section 408(b)(2)(ii), “that there is a reasonable certainty that no harm will result from aggregate exposure to the pesticide chemical resi due, including all anticipated dietary exposures and all other exposures for which there is reliable information.” Use of

DCDIC in food contact articles is interpreted as a food use. Therefore, a dietary risk assessment will be needed to determine if there are any potential dietary concerns from indirect food exposures to DCDIC. EPA will perform a risk assessment to determine if tolerances or exemptions from tolerances will be needed to support the existing registered

uses of DCDIC.

Aggregate and Cumulative Exposure

In examining aggregate exposure, EPA takes into account the available and reliable information concerning exposures to pesticide residues in food and drinking water, as well as non-occupa tional pesticide exposures. An aggregate assessment is needed and expected to be comprised of human exposures to DCDIC derived from dietary exposure (food), depending on the outco me of the needed environmental fate and exposure studies. The aggregate assessmen t may include dietary exposure (drinking water) and/or residential exposure to be dete rmined during the risk assessment stage of this Registration Review.

Section 408(b)(2)(D)(v) of FFDCA require s that, when considering whether to establish, modify, or revoke a tolerance, th e Agency consider "available information”Docket Number; EPA-HQ-OPP-2009-0723 www.regulations.gov

9 concerning the cumulative effects of a part icular pesticide's residues and "other

substances that have a common mechanism of toxicity.” EPA has not yet determined

whether DCDIC has a common mechanism with other compounds; consequently, a cumulative assessment will not be performed at this time.

Occupational and Resi dential Assessment

An occupational and/or residential exposur e assessment is required for an active ingredient if (1) certain toxi cological criteria are triggere d and (2) there is potential exposure to handlers (mixers, loaders, applicat ors, etc.) during use or to persons entering treated sites after application is complete. Th e Agency believes the existing toxicological data trigger the need for an inhalation and dermal occupational risk assessment based on potential exposure from open- pour mixing/loading systems.

The additional occupational exposure guideline studies anticipated to be needed to conduct an inhalation and dermal occupationa l risk assessment from exposures from open-pour mixing/loading scenarios (pulp and paper, recirculation cooling towers, and petroleum secondary recovery operations), include:

o (GLN 875.1200) Dermal Indoor Exposure;

o (GLN 875.1400) Inhalation Indoor Exposure;

o (GLN 875.1600) Data Reporti ng and Calculations; and,

o (GLN 875.1700) Product Use Information

Based on review of the current DCDIC end- use, the Agency anticipated that there will be no residential exposures; a resident ial handler assessment will not be needed. Because of low vapor pressure <9.16 x 10 -6 torr at 25oC and dilution rates of end use products, occupational post-application and re sidential post-application exposures are expected to be negligible and these part icular risk assessments are not needed.

It should be noted that one active formul ating product label cites a paint use. The Agency was not able to identify an applicati on rate for this paint use on the formulating product label and was not able to determine how this product is to be used. Without an application rate, product use, or valid exposure studies, the Agency can not adequately assess the paint use. The registrant would need to submit data to support the paint uses, so the Agency could develop occupational and re sidential assessments to determine if the paint uses are a risk concern to occupa tional workers and residential homeowners.

As a result the Agency would anticipate needing specific occupational and residential occupational handler studies to support the paint uses in registration review. The Agency anticipates that the data needed to support the paint use would include the following studies:

o (GLN 875.1200) Dermal Indoor Exposur e (airless painting and paint brush applicator exposure)Docket Number; EPA-HQ-OPP-2009-0723 www.regulations.gov

10 o (GLN 875.1400) Inhalation Indoor Exposur e (airless painting and paint brush applicator exposure) o (GLN 875.1600) Data Repor ting and Calculations o (GLN 875.1700) Product Use Information

Anticipated Human Health Data Needs

The Agency anticipates needing the follo wing toxicity and exposure studies to assess the DCDIC registration review case:

Toxicity Data Needs

o (GLN 870.3465) 90-day Inha lation Toxicity Study

o (GLN 870.3100) 90-day Oral Toxicity- Rodent

o (GLN 870.3800) Reproduction and Fertility Effects

Occupational Handler Exposure Data Needs

o (GLN 875.1200) Dermal Indoor Exposure

o (GLN 875.1400) Inhalation Indoor Exposure

o (GLN 875.1600) Data Repor ting and Calculations

o (GLN 875.1700) Product Use Information

Further information is available in the document titled, “Disodium Cyanodithioimidocarbonate. Human Health Effects Scoping Document for the Registration Review Decision,” dated December 7, 2009.

Environmental Fate and Ecological Risk Assessment Status and Data Needs

The Agency reviewed the environmental fate and ecological hazard databases for DCDIC. Based on its review, EPA believes risk assessments are needed to ensure that the DCDIC registration review case meets the FI FRA standards. The Agency will complete the environmental fate and ecological hazard risk assessments presented below.

Further information is available in the document titled, “Summary of Product Chemistry, Environmental Fate, and Ecotoxicity Data for the Disodium Cyanodithioimidocarbonate Registration Revi ew Decision Document,” dated December
7, 2009.

Environmental fate and ecological risk assessments have not been conducted for DCDIC. The use of DCDIC as a materials pres ervative, and industrial slimicides used in recirculating water cooling towers and pape r mills that potentia lly pass through waste water treatment plants (WWTPs) could poten tially result in environmental exposure. Therefore, the Agency will conduct environmenta l fate and ecological risk assessments to assess environmental exposure. The Agency also anticipates that environmental fate and ecological data will be needed to conduct these assessments.Docket Number; EPA-HQ-OPP-2009-0723 www.regulations.gov

11 The Agency has not conducted a risk assessment that supports a complete endangered species determination for DCDIC. The ecological risk assessment planned during registration review will allow the Agency to determine whether use of DCDIC has “no effect” or “may affect” federally liste d threatened or endangered species (listed species) or their designated critical habita ts. 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 and Wildlife Service and/or National Marine Fisheries Service (the Services ), as appropriate.

Anticipated Environmental Fate and Ecological Data Needs

The Agency has not conducted an envi ronmental fate assessment for DCDIC. However, the Agency anticipates needing to conduct an environmental fate assessment for material preservatives, a nd industrial slimicides used in recirculating water cooling towers and paper mills that potentially pass through waste water treatment plants (WWTPs) and may be discharged into terrestrial and aquatic environments.

The Agency anticipates needing the followi ng data in order to conduct a complete

environmental fate assessment:

o (GLN 835.2120) 5-day hydrolysis study at 50oC in basic conditions;

o (GLN 835.2240) photodegradation in water study;

o (GLN 850.6800) modified activated sludge respiration inhibition;

o (GLN 835.1110) activated sludge sorption isotherm; and

o (GLN 835.3110) ready biodegradability.

The Agency anticipates needing the followi ng data in order to conduct a complete ecological risk assessment, including an endangered species assessment:

o (GLN 850.5400) algal toxicity (Tier II) using freshwater green alga, Selenastrum capricornutum.

Anticipated Physical/Chemical Property Data Needs

All product chemistry data requirements have been fulfilled; therefore, the Agency does not anticipate needing a dditional product chemistry data for DCIC

.

Incidents

One reported incident was identified in the OPP Incident database. An occupational worker developed a rash that required hospitalization after using a DCDIC product. The Agency notes that the product as sociated with the incident is no longer registered.

Endocrine Disruptor Screening ProgramDocket Number; EPA-HQ-OPP-2009-0723 www.regulations.gov

12 As required under FFDCA section 408(p) , EPA has developed the Endocrine Disruptor Screening Program (EDSP) to dete rmine 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 EDSP 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 interact 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. Ti er 2 testing is designed to identify any adverse endocrine related effects caused by th e substance, and esta blish a dose-response relationship between the dose a nd the E, A, or T effect.

Between October 2009 and February 2010, EPA issued test orders/data call-ins for the first group of 67 chemicals, which c ontains 58 pesticide ac tive ingredients and 9 inert ingredients. This list of chemicals was selected based on the potential for human exposure through pathways such as food and wa ter, residential activity, and certain postapplication agricultural scenarios. This list should not be construed as a list of known or likely endocrine disruptors.

DCDIC is not among the group of 58 pesticid e active ingredients on the initial list

to be screened under the EDSP. Under FFDCA sec. 408(p) the Agency must screen all pesticide chemicals. Accordingly, EPA anticipates issuing future EDSP test orders/data call-ins for all pesticide active ingredients.

For further information on the status of the EDSP, the policies and procedures, the list of 67 chemicals, the test guidelines and the Tier 1 screening battery, please visit our

website: http://www.epa.gov/endo/

.Docket Number; EPA-HQ-OPP-2009-0723 www.regulations.gov

13 IV. TIMELINE

The EPA has created the following estimated timeline for the completion of the DCDIC registration review case. The Agency anticipates requiring additional data and residential, occupational and ecological exposure assessments for this registration review

case.

Anticipated Schedule

Activities Estimated Month/Year Phase 1: Opening the docket
Open Public Comment Period for DCDI C Docket Completed December 2009
Close Public Comment Period Completed March 2010
Phase 2: Case Development

Develop Final Work Plan (FWP) Completed June 2010

Issue DCI June 2011

Data Submission June 2013
Open Public Comment Period for Preliminary Risk Assessments December 2014

Close Public Comment Period March 2014

Phase 3: Registration Review Decision
Open Public Comment Period for Proposed Reg. Review Decision June 2015
Close Public Comment Period September 2015 Final Decision and Begin Post-Decision Follow-up 2015 Total (years) 6

Next Steps

The Agency plans to develop a Data Call-In for this pesticide and expects to issue

it in June 2011.Docket Number; EPA-HQ-OPP-2009-0723 www.regulations.gov

14 V. GLOSSARY of TERMS & ABBREVIATIONS

ai Active Ingredient AR Anticipated Residue ASTM American Society for Testing and Materials

AWPA American Wood Preserver’s Association

CBI Confidential Business Information CFR Code of Federal Regulations cPAD Chronic Population Adjusted Dose

CSF Confidential Statement of Formula CSFII USDA Continuing Surveys for Food Intake by Individuals

DCI Data Call-In DEEM Dietary Exposure Evaluation Model DFR Dislodgeable Foliar Residue DNT Developmental Neurotoxicity DWLOC Drinking Water Level of Comparison

EC Emulsifiable Concentrate Formulation EDWC Estimated Drinking Water Concentration

EEC Estimated Environmental Concentration

EP End use Product EPA Environmental Protection Agency

EUP End-Use Product FDA Food and Drug Administration FIFRA Federal Insecticide, Fungicide, and Rodenticide Act FFDCA Federal Food, Drug, and Cosmetic Act FQPA Food Quality Protection Act FOB Functional Observation Battery GENEEC Tier I Surface Water Computer Model

IR Index Reservoir

LC 50 Median Lethal Concentration. A statistically derived concentration of a substance that can be expected to cause death in 50% of test animals. It is usually expressed as the weight of substance per weight or volume of water, air or feed, e.g., mg/l, mg/kg or ppm.

LD 50 Median Lethal Dose. A statistically deri ved single dose that can be expected to

cause death in 50% of the test animals when administered by the route indicated (oral, dermal, inhalation). It is expressed as a weight of substance per unit weight of animal, e.g., mg/kg.

LOC Level of Concern

LOAEL Lowest Observed Adverse Effect Level μg/g Micrograms Per Gram μg/L Micrograms Per Liter mg/kg/day Milligram Per Kilogram Per Day mg/L Milligrams Per Liter MOE Margin of Exposure

MRID Master Record Identifi cation (number). EPA's system of recording and tracking

submitted studies. MUP Manufacturing-Use Product NA Not Applicable NAWQA USGS National Ambient Water Quality Assessment NPDES National Pollutant Discharge Elimination System NR Not Required

NOAEL No Observed Adverse Effect Level OPP EPA Office of Pesticide Programs OPPTS EPA Office of Prevention, Pesticides and Toxic Substances PAD Population Adjusted DoseDocket Number; EPA-HQ-OPP-2009-0723 www.regulations.gov

15 PAIRA Pure Active Ingredient Radiolabelled PCA Percent Crop Area PDP USDA Pesticide Data Program PHED Pesticide Handler's Exposure Data

PHI Preharvest Interval phr Pounds Per Hundred ppb Parts Per Billion PPE Personal Protective Equipment ppm Parts Per Million PRZM/EXAMS Tier II Surface Water Computer Model Q 1 * The Carcinogenic Potential of a Compound, Quantified by the EPA's Cancer

Risk Model RAC Raw Agriculture Commodity RED Reregistration Eligibility Decision REI Restricted Entry Interval

RfD Reference Dose RQ Risk Quotient RTU Ready to Use SCI-GROW Tier I Ground Water Computer Model SAP Science Advisory Panel SF Safety Factor SLN Special Local Need (Registrati ons Under Section 24©) of FIFRA) TGAI Technical Grade Active Ingredient TEP Typical End-Use Product USDA United States Department of Agriculture UF Uncertainty Factor

WPS Worker Protection Standard