United States Chemical Safety June 2012 

Environmental Protection and Pollution Prevention 

Agency (7510P) 

 

Dibromodicyanobutane 

Summary Document: 

Registration Review: Initial Docket 

June 2012 

 

Docket Number: EPA-HQ-OPP-2012-0342 

www.regulations.gov

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TABLE OF CONTENTS 

Dibromodicyanobutane Registration Review Team ............................................................4 

I. Preliminary Work Plan .....................................................................................................5

II. Fact Sheet ......................................................................................................................13 

III. Summary of Anticipated Data Requirements ..............................................................17 

IV. Appendix A ..................................................................................................................19 

________________________________________ 

Please Note 

This Preliminary Work Plan and Fact Sheet summarize the Environmental Protection Agency's 

current position based on the following documents: 

1. Product Chemistry, Environmental Fate, and Ecological Effects Scoping Document in 

Support of Registration Review of Dibromodicyanobutane. May 31, 2012 

2. 1,2-Dibromo-2,4-dicyanobutane (DBDCB): Human Health Registration Review Scoping 

Document. May 3, 2012 

Additional supporting documents for the Dibromodicyanobutane Case may be found in the 

registration review docket EPA-HQ-OPP-2012-0342 located on the internet at

www.regulations.gov. 
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Dibromodicyanobutane Registration Review Team

Human Health & Environmental Effects

Timothy Dole 

Jenny Tao 

Jonathan Chen 

Talia Lindheimer 

Srinivas Gowda 

David Bays 

James Breithaupt 

Risk Management

Seiichi Murasaki 

Lance Wormell 

Office of General Counsel

Philip Ross 
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I. Preliminary Work Plan -- Dibromodicyanobutane 

Introduction:

The Food Quality Protection Act (FQPA) of 1996 mandated a registration review program. All 

pesticides distributed or sold in the United States generally must be registered by the U.S. 

Environmental Protection Agency (USEPA, EPA, or the Agency) based on scientific data 

showing that they will not cause unreasonable risks to human health or the environment when 

used as directed on product labeling. The registration review program is intended to make sure 

that, as the ability to assess risk evolves and as policies and practices change, all registered 

pesticides continue to meet the statutory standard of no unreasonable adverse effects to human 

health or the environment. Changes in science, public policy, and pesticide use practices will 

occur over time. Through the registration review program, the Agency periodically reevaluates 

pesticides to make sure that as change occurs, products in the marketplace can be used safely. 

Information on this program is provided at http://www.epa.gov/oppsrrd1/registration_review/. 

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. The Agency will consider benefits information and data as required by FIFRA. The 

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

docket is the Agency’s opportunity to state what it knows about the pesticide and what additional 

risk analyses and data or information it believes are needed to make a registration review 

decision. After reviewing and responding to comments and data received in the docket during 

this initial comment period, the Agency will develop and commit to a final work plan and 

schedule for the Dibromodicyanobutane Case. 

The first product containing 1-Bromo-1-(bromomethyl)-1,3-propanedicarbonitrile 

(Dibromodicyanobutane or DBDCB) (PC Code 111001) as an active ingredient was registered in 

the United States in 1980. Currently, there are 16 products containing DBDCB as an active 

ingredient registered with EPA. Dibromodicyanobutane is registered for use in materials 

preservation, industrial recirculating cooling water treatment, oil production, and paper mill 

water treatment. The material preservation uses include adhesives, caulks, household cleaning 

solution, paints and coatings, metal working fluids and non-apparel textiles. DBDCB is regulated 

by the FDA as an indirect food additive. Tolerances have been established for DBDCB as a 

preservative in food grade adhesives (see 21 CFR § 175.105) and as a slimicide in the 

manufacture in food grade paper and paperboard at a maximum level of 0.005% of dry weight 

fiber (see 21 CFR § 176.300). 

The Agency completed a Reregistration Eligibility Decision (RED) for Dibromodicyanobutane 

in 1996. 

Documents associated with the registration review of Dibromodicyanobutane can be viewed at 

www.regulations.gov in docket EPA-HQ-OPP-2012-0342. Below is a summary of the issues 

relevant to this registration review case. 
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Anticipated Risk Assessment and Data Needs:

The Agency anticipates the need to conduct a comprehensive ecological risk assessment, 

including an endangered species risk assessment, for all uses of Dibromodicyanobutane. If 

endpoints of concern are identified from toxicological studies expected to be required for the 

registration review of DBDCB, the Agency anticipates the need to conduct quantitative dietary, 

residential, occupational, and, if appropriate, aggregate assessments. The Agency anticipates 

needing additional data for use in conducting the registration review for Dibromodicyanobutane. 

Ecological Risk: 

• The most recent ecological risk assessment for DBDCB was performed to support the 

1996 RED. 

• The Agency has not conducted a risk assessment that supports a complete endangered 

species determination for Dibromodicyanobutane. The ecological risk assessment 

planned during registration review will allow the Agency to determine whether 

DBDCB’s use has 'no effect' or 'may affect' federally listed threatened or endangered 

species (listed species) or their designated critical habitats. When an assessment 

concludes that a pesticide’s use 'may affect' a listed species or its designated critical 

habitat, the Agency will consult with the U.S. Fish and Wildlife Service and/or National 

Marine Fisheries Services (the Services), as appropriate. 

• The Agency anticipates the need to require the following additional ecological data for 

use in the registration review of Dibromodicyanobutane. 

850.4400 -- Aquatic plant toxicology test using Lemna spp.1

 

850.5400 -- Algal Toxicity (Tier II)2

• The Agency anticipates the need to require the following additional environmental fate 

data for use in the registration review of Dibromodicyanobutane. 

850.6800 -- Modified activated sludge, respiration inhibition test3

 

1

 If data indicate the IC50 for Selenastrum capricornutum is greater than 1000 ppb, the Agency will consider waiver 

requests for the Aquatic vascular plant toxicology test (850.4400). 

2

 Algal Toxicity Tier II data using Selenastrum capricornutum (Green Algae), Anabaena flos-aquae (Blue-Green 

Cyanobacteria), Navicula pelliculosa (Freshwater Diatom), and Skeletonema costatum (Marine Diatom) are 

expected to be required. If data indicate the IC50 for Selenastrum capricornutum is greater than 1000 ppb, the 

Agency will consider waiver requests for studies conducted with the other three algal species. 3

 The results of the Activated Sludge Respiration Inhibition Test (ASRI) expected to be required will determine 

which of these three biodegradation tests would be anticipated to be required. If the ASRI test EC50 is less than or 

equal to 20 mg/L, then either the Biodegradation in Activated Sludge Study or Simulation Test – Aerobic Sewage 

Treatment: A. Activated Sludge Units or the Porous Pot Test would be anticipated to be required. If the ASRI test 

EC50 is greater than 20 mg/L, then the DCI expected to be issued would provide that the registrant would choose to 

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 would be expected to be required. If, however, the 

antimicrobial fails the Ready Biodegradability study, then the Biodegradation in Activated Sludge or Simulation 
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835.3110 -- Ready Biodegradability3

835.3220 -- Porous Pot Test3

835.3280 -- Simulation Tests to Assess the Biodegradability of Chemicals Discharged 

to Wastewater3

835.3240 -- Simulation Test – Aerobic Sewage Treatment: A. Activated Sludge Units3

• For more information, please refer to Product Chemistry, Environmental Fate, and 

Ecological Effects Scoping Document in Support of Registration Review of 

Dibromodicyanobutane, located in the docket. 

Human Health Risk: 

• The most recent qualitative human health risk assessment for DBDCB was performed to 

support the 1996 RED. 

• Toxicological endpoints of concern were not identified at the time of the RED. If 

endpoints of concern are identified from toxicological studies expected to be required for 

the registration review of DBDCB, the Agency anticipates the need to conduct 

quantitative dietary, residential, occupational, and, if appropriate, aggregate assessments. 

• The Agency may need to conduct a dietary risk assessment based on indirect food 

exposure from DBDCB for use as a slimicide in food contact paper and paperboard 

production and to preserve paper-making chemicals. 

• The Agency may need to conduct a residential risk assessment based on exposure from 

DBDCB during use of treated paints and household cleaners. 

• The Agency may need to conduct an occupational risk assessment based on exposure 

from DBDCB during open pouring of liquids and wettable powders for material 

preservation and during the use of treated paints, metal working fluids, and cleaning 

solutions. 

• The Agency may need to conduct an aggregate assessment based on residential and 

dietary exposures. 

• The Agency anticipates the need to require the following additional human health data 

for use in the registration review of DBDCB. 

870.3465 -- 90-day inhalation toxicity4

870.3800 – Two-Generation Reproduction5

875.1200 -- Dermal indoor exposure6

 Test – Aerobic Sewage Treatment: A. Activated Sludge Units, or the Porous Pot study would be expected to be 

required. 

4

 Study is anticipated as being needed for following scenarios: open-pour liquids; open-pour wettable powders; 

application of preserved paints using brush/roller or airless sprayer; use of treated metalworking fluids; and trigger 

sprayer, wipe, and mop application of preserved cleaners. 

5

 Study is anticipated as being needed for all uses that can result in dietary and drinking water exposures. 
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875.1400 -- Inhalation indoor exposure6

875.1600 -- Application exposure data reporting and calculations6

875.1700 -- Product use information 

875.2300 -- Indoor surface residue dissipation7

Special Study -- Nature of Residue on Surfaces8

Special Study -- Migration Study8

• For more information, please refer to 1,2-Dibromo-2,4-dicyanobutane (DBDCB): Human 

Health Registration Review Scoping Document, located in the docket. 

Product Chemistry: 

• The Agency does not anticipate the need to require additional product chemistry data for 

this registration review at this time. 

• For more information, please refer to Product Chemistry, Environmental Fate, and 

Ecological Effects Scoping Document in Support of Registration Review of 

Dibromodicyanobutane, located in the docket. 

Endocrine Disruptor Screening Program

As required by FIFRA and FFDCA, EPA reviews numerous studies to assess potential adverse 

outcomes from exposure to chemicals. Collectively, these studies include acute, subchronic and 

chronic toxicity, including assessments of carcinogenicity, neurotoxicity, developmental, 

reproductive, and general or systemic toxicity. These studies include endpoints which may be 

susceptible to endocrine influence, including effects on endocrine target organ histopathology, 

organ weights, estrus cyclicity, sexual maturation, fertility, pregnancy rates, reproductive loss, 

and sex ratios in offspring. For ecological hazard assessments, EPA evaluates acute tests and 

chronic studies that assess growth, developmental and reproductive effects in different 

taxonomic groups. As part of the re-registration eligibility decision in 1996 for 

dibromodicyanobutane , EPA reviewed the available toxicology data and determined that there 

were no endpoints of concern for the existing use patterns. However, as required by FFDCA 

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 Exposure studies are anticipated as being needed for following scenarios: open-pour liquids; open-pour wettable 

powders; application of preserved paints using brush/roller or airless sprayer; use of treated metalworking fluids; 

and trigger sprayer, wipe, and mop application of preserved cleaners. If labels are amended to require closed 

mixing/loading, then any required exposure study for open-pour liquid scenarios can likely be waived. If labels are 

amended to require water soluble packaging, then any required exposure study for open-pour wettable powder 

scenarios can likely be waived. It may be possible to use proprietary surrogate exposure data if data compensation 

issues are adequately addressed. 

7

 Study is anticipated as being needed for following scenario: residential post application dermal and incidental oral 

exposure to floors cleaned with preserved household cleaning solutions. The anticipated DCI will provide that a 

protocol must be submitted for review and approval by the Agency prior to initiating this study. 

8

 Study is anticipated as being needed for following scenarios: dietary exposures from countertops cleaned with 

preserved household cleaning solution; and dietary exposures from DBDCB treated paper products used in food 

packaging. The anticipated DCI will provide that a protocol must be submitted for review and approval by the 

Agency prior to initiating this study. In the absence of additional data, a default transfer factor of 100% would be 

expected to be used. 
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section 408(p), Dibromodicyanobutane is subject to the endocrine screening part of the 

Endocrine Disruptor Screening Program (EDSP). 

EPA has developed the EDSP to determine whether certain substances (including pesticide 

active and other ingredients) may have an effect in humans or wildlife similar to an effect 

produced by a “naturally occurring estrogen, or other such endocrine effects as the Administrator 

may designate.” The EDSP employs a two-tiered approach to making the statutorily required 

determinations. Tier 1 consists of a battery of 11 screening assays to identify the potential of a 

chemical substance to interact with the estrogen, androgen, or thyroid (E, A, or T) hormonal 

systems. Chemicals that go through Tier 1 screening and are found to have the potential to 

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. Tier 2 

testing is designed to identify any adverse endocrine-related effects caused by the substance, and 

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

Under FFDCA section 408(p), the Agency must screen all pesticide chemicals. Between October 

2009 and February 2010, EPA issued test orders/data call-ins for the first group of 67 chemicals, 

which contains 58 pesticide active ingredients and 9 inert ingredients. Dibromodicyanobutane is 

not among the group of 58 pesticide active ingredients on the initial list to be screened under the 

EDSP. Accordingly, as part of registration review, EPA will issue future EDSP orders/data callins, requiring the submission of EDSP screening assays for Dibromodicyanobutane. For further 

information on the status of the EDSP, the policies and procedures, the list of 67 chemicals, 

future lists, the test guidelines and the Tier 1 screening battery, please visit our website: 

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

Timeline

EPA has created the following estimated timeline for the completion of the 

Dibromodicyanobutane registration review: 

Anticipated Schedule

Activities Estimated Month/Year

Phase 1: Opening the docket 

Open Public Comment Period for Docket June 2012

Close Public Comment Period for Docket August 2012 

Phase 2: Case Development 

Develop Final Work Plan (FWP) December 2012 

Issue DCI December 2013 

Data Submission December 2017 

Open Public Comment Period for Preliminary Risk Assessments June 2019 

Close Public Comment Period for Preliminary Risk Assessments July 2019 

Phase 3: Registration Review Decision 

Open Public Comment Period for Proposed Reg. Review Decision December 2019 

Close Public Comment Period for Proposed Reg. Review Decision February 2020 
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Final Decision and Begin Post-Decision Follow-up 2020 

Total (years) 8 

Guidance for Commenters:

The public is invited to comment on EPA’s Preliminary Work Plan and rationale. The Agency 

will carefully consider all comments as well as any additional information or data provided in a 

timely manner prior to issuing a final work plan for the Dibromodicyanobutane registration 

review case. 

Trade Irritants:

Through the registration review process, the Agency intends to solicit information on trade 

irritants and, to the extent feasible, take steps toward facilitating irritant resolution. Growers and 

other stakeholders are asked to comment on any trade irritant issues resulting from lack of 

Maximum Residue Limits (MRLs) or disparities between U.S. tolerances and MRLs in key 

export markets, providing as much specificity as possible regarding the nature of the concern. 

Water Quality:

Dibromodicyanobutane is not identified as a cause of impairment for any water bodies listed as 

impaired under section 303(d) of the Clean Water Act, based on information provided at 

http://iaspub.epa.gov/tmdl_waters10/attains_nation_cy.cause_detail_303d?p_cause_group_id=88

5. In addition, no Total Maximum Daily Loads (TMDL) have been developed for 

Dibromodicyanobutane, based on information provided at 

http://iaspub.epa.gov/tmdl_waters10/attains_nation.tmdl_pollutant_detail?p_pollutant_group_id

=885&p_pollutant_group_name=PESTICIDES. 

More information on impaired water bodies and TMDLs can be found at 

http://www.epa.gov/owow/tmdl/. The Agency invites submission of water quality data for this 

pesticide. To the extent possible, data should conform to the quality standards in Appendix A of 

the OPP Standard Operating Procedure: Inclusion of Impaired Water Body and Other Water 

Quality Data in OPP’s Registration Review Risk Assessment and Management Process (see: 

http://www.epa.gov/oppsrrd1/registration_review/water_quality_sop.htm), in order to ensure the 

data can be used quantitatively or qualitatively in pesticide risk assessments. 

Environmental Justice:

EPA seeks to achieve environmental justice, the fair treatment and meaningful involvement of all 

people, regardless of race, color, national origin, or income, in the development, implementation, 

and enforcement of environmental laws, regulations, and policies. To help address potential 

environmental justice issues, the Agency seeks information on any groups or segments of the 

population who, as a result of their location, cultural practices, or other factors, may have 

atypical, unusually high exposure to Dibromodicyanobutane compared to the general population. 

Please comment if you are aware of any sub-populations that may have atypical, unusually high 

exposure compared to the general population. 
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Structure Activity Relationships: 

EPA must rely upon information of appropriate quality and reliability for each decision made by 

the Agency. In the Office of Pesticide Programs (OPP), the evaluation process for a pesticide 

chemical traditionally begins with the applicant’s submission of a set of studies conducted with 

the specific pesticide chemical of interest. The use of the results of such testing (measured data) 

is a logical, scientifically rigorous process that identifies the physical, chemical, and 

environmental fate properties of the pesticide, as well as the dose and endpoints at which an 

adverse effect can occur in various animal species. 

Today, there is significant interest in alternative techniques, i.e., techniques other than data 

generation that could significantly inform the Agency’s decision-making process. Recently, OPP 

has made increasing use of structure activity relationship (SAR) as part of its regulatory 

decision-making process. In the SAR process, a chemical's molecular structure is compared to 

that of other chemicals for which data are available. These structural similarities are then used to 

make predictive judgments about a chemical’s physical, chemical, and biological properties. 

Thus, the chemical’s physical, chemical, and biological properties are a function of (or directly 

related to) the chemical’s molecular structure. Quantitative SAR is referred to as QSAR. To 

develop a QSAR, a selected set of measured data on a single physical, chemical, or biological 

property is used to derive a model (an equation) to predict the value of that property. 

Since SAR assessments and QSAR modeling are another set of tools that are available to Agency 

scientists, OPP has begun a process shift that envisions shifting from the current study-by-study 

approach to an approach in which the use of predicted data, generated using validated models, is 

considered along with information from open literature and studies specifically generated under 

Part 161 requirements. All relevant information would be considered as part of a weight-of-theevidence evaluation. 

At this time, EPA believes that for certain endpoints, especially physical/chemical and fate 

properties, that SAR and QSAR might be effectively utilized to fulfill these data requirements 

for many antimicrobial pesticide chemicals. When considering biological properties, at this time, 

EPA believes that SAR and QSAR can be most effectively utilized in the evaluation of 

chemicals that exhibit lower toxicity for human health and/or ecotoxicity parameters. This is 

appropriate because the risk assessment for lower toxicity chemicals can be stream-lined, i.e., a 

screening-level assessment procedure rather than multiple tiers of assessments with progressively 

more data requirements. 

If stakeholders believe that submission of predicted data can fulfill one of the data needs for the 

Dibromodicyanobutane case, then the Agency invites submission of this information. The 

submitter would be expected to supply a rationale describing the utility of the information and 

provide documentation on the scientific validity of the information. The determination that the 

predicted data fulfills the data requirement would be at the sole discretion of the Agency. Presubmission consultation with the Agency is encouraged. 

Additional Information:
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Stakeholders are also specifically asked to provide available information and data that will assist 

the Agency in refining its risk assessments, including any species-specific ecological effects 

determinations. The Agency is interested in receiving the following information: 

1. Confirmation on the following label information: 

a. Sites of application 

b. Formulations 

c. Application methods and equipment 

d. Maximum application rates 

e. Frequency of application, application intervals and maximum number of 

applications 

f. Geographic limitations on use 

2. Use or potential use distribution 

3. Use history 

4. Usage/use information for non-agricultural uses (e.g., materials preservation) 

5. Typical application interval 

6. State or local use restrictions 

7. Ecological incidents (non-target plant damage and avian, fish, reptilian, amphibian 

and mammalian mortalities) not already reported to the Agency 

8. Monitoring data 

Next Steps:

After the 60-day comment period closes in August 2012, the Agency will review and respond to 

any comments received in a timely manner, and then issue a Final Work Plan for the 

Dibromodicyanobutane case. 
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II. Fact Sheet 

Background Information:

• Active Ingredient: 1-Bromo-1-(bromomethyl)-1,3-propanedicarbonitrile 

(Dibromodicyanobutane) 

• Case number: 2780 

• PC Code: 111001 

• CAS number: 35691-65-7 

• Technical registrants: Lanxess Corporation 

• First approved for use in a registered product: 1980 

• DBDCB is regulated by the FDA as an indirect food additive. Tolerances have been 

established for DBDCB as a preservative in food grade adhesives (see 21 CFR § 

175.105) and as a slimicide in the manufacture in food grade paper and paperboard at a 

maximum level of 0.005% of dry weight fiber (see 21 CFR § 176.300). 

• Antimicrobials Division Chemical Review Manager (CRM): Seiichi Murasaki, 

murasaki.seiichi@epa.gov

• Antimicrobials Division Product Manager (PM): Jacqueline Campbell-McFarlane, 

campbell-mcfarlane.jacqueline@epa.gov

• Chemical Structure: 

Use & Usage Information:

• Dibromodicyanobutane (DBDCB) is registered for use in materials preservation, 

industrial recirculating cooling water treatment, oil production, and paper mill water 

treatment. The material preservation uses include adhesives, caulks, household cleaning 

solution, paints and coatings, metal working fluids and non-apparel textiles. 

Recent/Pending Regulatory Actions:

• There are no pending regulatory actions for DBDCB.

Ecological Risk Assessment Status:

Please refer to Product Chemistry, Environmental Fate, and Ecological Effects Scoping 

Document in Support of Registration Review of Dibromodicyanobutane, located in the docket, 

for a detailed discussion of the ecological risk assessments. 

• DBDCB is moderately toxic to freshwater and estuarine/marine animals and slightly 

toxic to birds and mammals. For use in conducting an ecological risk assessment, 

including an endangered species assessment for all uses, the Agency anticipates requiring 
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an algal (Tier II) toxicity study using freshwater green alga. No toxicity data is available 

for the MGN degradate, toxicity of this degradate will be assumed to be as toxic as the 

parent. 

Human Health Risk Assessment Status:

The following are key findings of the recent human health risk assessments for 

Dibromodicyanobutane. Please refer to 1,2-Dibromo-2,4-dicyanobutane (DBDCB): Human 

Health Registration Review Scoping Document, located in the docket, for a detailed discussion of 

the human health risk assessment. 

Hazard Characterization: 

• Toxicological endpoints of concern were not identified at the time of the RED. 

• Based on acute toxicity data, DBDCB is of low oral toxicity (Toxicity Category III), low 

dermal toxicity (Toxicity Category IV), and low inhalation toxicity (Toxicity Category 

IV). DBDCB is a severe dermal and eye irritant (Toxicity Category I). It is not a 

sensitizer in animals but is a dermal sensitizer in humans. 

Dietary (Food and Water): 

• Dietary (food) exposure to DBDCB is possible since it is used as a slimicide in food 

contact paper and paperboard production and to preserve paper-making chemicals and 

migration of DBDCB from paper packaging to the food contents may occur. 

• Material preservative uses of DBDCB may lead to contamination of human and livestock 

drinking water through the discharge of waste water. DBDCB and/or its degradates could 

potentially pass through wastewater treatment plants (WWTPs). The Agency will 

determine the need for a dietary drinking water risk assessment following the submission 

and review of environmental fate data that are anticipated to be required 

Residential: 

• Residential dermal and inhalation exposures to DBDCB could occur during use of treated 

paints and household cleaners. Residential incidental oral exposures could occur for 

toddlers playing on floors cleaned with treated cleaning solutions. 

Aggregate: 

• EPA has not conducted an aggregate risk assessment for DBDCB. 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 nonoccupational pesticide exposures. The Agency may need to conduct an aggregate 

assessment based on residential and dietary exposures. 
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Occupational: 

• Occupational dermal and inhalation exposures to DBDCB could occur during open 

pouring of liquids and wettable powders for material preservation and during the use of 

treated paints, metal working fluids, and cleaning solutions. 

Cumulative: 

• EPA does not have, at this time, available data to determine whether 

Dibromodicyanobutane has a common mechanism of toxicity with other substances or 

how to include this pesticide in a cumulative risk assessment. For the purposes of this 

Registration Review, EPA has assumed that Dibromodicyanobutane does not have a 

common mechanism of toxicity with other substances when used as an antimicrobial as 

registered. 

Incidents:

Ecological: 

• No Dibromodicyanobutane incidents have been reported in the Agency’s Ecological 

Incident Information System (EIIS). 

Human Health: 

• No Dibromodicyanobutane human poisoning incidents have been reported in the OPP’s 

Incident Data System (IDS). 

Tolerances and International Harmonization: 

• DBDCB is regulated by the FDA as an indirect food additive. Tolerances have been 

established for DBDCB as a preservative in food grade adhesives (see 21 CFR § 

175.105) and as a slimicide in the manufacture in food grade paper and paperboard at a 

maximum level of 0.005% of dry weight fiber (see 21 CFR § 176.300). 

Data Call-In Status:

• There are no outstanding data call-in (DCI) requirements for DBDCB. 

Labels: 

Registered products, including EPA registration numbers are provided in Table 1 below. For 

future reference, during registration review a list of product registration numbers will be included 

in the docket. Product registration labels may be obtained from the Pesticide Product Label 

System (PPLS) website at: http://oaspub.epa.gov/pestlabl/ppls.home. 
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Table 1. Registered Products – Dibromodicyanobutane 

Registration # Registration Name Company Name Formulation Type % 

A.I. 

39967-28 BIOCHEK 721M Lanxess Corporation Ready-to-Use Solution 12 

39967-29 TEKTAMER 38 LIQUID 

CONCENTRATE Lanxess Corporation Ready-to-Use Solution 25 

39967-32 TEKTAMER 38 Lanxess Corporation Formulation 

Intermediate 99.9 

39967-34 TEKTAMER 38 A.D. Lanxess Corporation Ready-to-Use Solution 25.5 

39967-36 METASOL CB 225-AD Lanxess Corporation Ready-to-Use Solution 25 

39967-37 METASOL CB 225-LC Lanxess Corporation Ready-to-Use Solution 25 

39967-38 BIOCHEK 430 Lanxess Corporation Ready-to-Use Solution 23.73 

39967-39 BIOCHEK 410 Lanxess Corporation Ready-to-Use Solution 19 

39967-40 METASOL CB-220 Lanxess Corporation Ready-to-Use Solution 20 

39967-41 TEKTAMER 38 WET CAKE Lanxess Corporation Formulation 

Intermediate 85 

39967-62 TEKTAMER 38 MU Lanxess Corporation Technical Chemical 99.9 

39967-110 DBDCB AD Lanxess Corporation Ready-to-Use Solution 25 

39967-111 DBDCB Lanxess Corporation Emulsifiable 

Concentrate 98 

39967-117 VERIGUARD 3003 Lanxess Corporation Soluble Concentrate 10 

59106-2 BIOCLEAR 750 Clearwater International, 

LLC Wettable Powder 78.4 

59106-3 BIOCLEAR 550 FIZZY TABS Clearwater International, 

LLC Pelleted/Tableted 25 

 
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III. Summary of Anticipated Data Requirements – DBDCB 

The table below summarizes anticipated data needs for the Dibromodicyanobutane Case in 

Section I of this document (Preliminary Work Plan), Product Chemistry, Environmental Fate, 

and Ecological Effects Scoping Document in Support of Registration Review of 

Dibromodicyanobutane, and 1,2-Dibromo-2,4-dicyanobutane (DBDCB): Human Health 

Registration Review Scoping Document. 

Table 2. Summary of Anticipated Data Requirements – Dibromodicyanobutane 

Guideline 

Number Anticipated Data Requirement Test Material 

Estimated 

Timeframe 

(Measured in 

months from DCI 

Receipt) 

850.4400 Aquatic plant toxicology test using Lemna spp.9 TGAI 12 

850.5400 Algal Toxicity (Tier II)10 TGAI 12 

850.6800 Modified activated sludge, respiration inhibition test11 TGAI 12 

835.3110 Ready Biodegradability11 TGAI 12 

835.3220 Porous Pot Test11 TGAI 12 

835.3280 Simulation Tests to Assess the Biodegradability of 

Chemicals Discharged to Wastewater11 TGAI 12 

835.3240 Simulation Test – Aerobic Sewage Treatment: A. 

Activated Sludge Units11 TGAI 12 

870.3465 90-day inhalation toxicity12 TGAI 24 

 

9

 If data indicate the IC50 for Selenastrum capricornutum is greater than 1000 ppb, the Agency will consider waiver 

requests for the Aquatic vascular plant toxicology test (850.4400). 

10 Algal Toxicity Tier II data using Selenastrum capricornutum (Green Algae), Anabaena flos-aquae (Blue-Green 

Cyanobacteria), Navicula pelliculosa (Freshwater Diatom), and Skeletonema costatum (Marine Diatom) are 

expected to be required. If data indicate the IC50 for Selenastrum capricornutum is greater than 1000 ppb, the 

Agency will consider waiver requests for studies conducted with the other three algal species. 11 The results of the Activated Sludge Respiration Inhibition Test (ASRI) expected to be required will determine 

which of these three biodegradation tests would be anticipated to be required. If the ASRI test EC50 is less than or 

equal to 20 mg/L, then either the Biodegradation in Activated Sludge Study or Simulation Test – Aerobic Sewage 

Treatment: A. Activated Sludge Units or the Porous Pot Test would be anticipated to be required. If the ASRI test 

EC50 is greater than 20 mg/L, then the DCI expected to be issued would provide that the registrant would choose to 

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 would be expected to be required. If, however, the 

antimicrobial fails the Ready Biodegradability study, then the Biodegradation in Activated Sludge or Simulation 

Test – Aerobic Sewage Treatment: A. Activated Sludge Units, or the Porous Pot study would be expected to be 

required. 

12 Study is anticipated as being needed for following scenarios: open-pour liquids; open-pour wettable powders; 

application of preserved paints using brush/roller or airless sprayer; use of treated metalworking fluids; and trigger 

sprayer, wipe, and mop application of preserved cleaners. 
Docket Number: EPA-HQ-OPP-2012-0342 

www.regulations.gov

18 of 23 

870.3800 Two-Generation Reproduction13 TGAI 48 

875.1200 Dermal indoor exposure14 TGAI 12 

875.1400 Inhalation indoor exposure14 TGAI 12 

875.1600 Application exposure data reporting and calculations14 TGAI 12 

875.1700 Product use information TGAI 12 

875.2300 Indoor surface residue dissipation15 TGAI 24 

Special 

Study Nature of Residue on Surfaces16 TGAI 24 

Special 

Study Migration Study16 TGAI 24 

 

13 Study is anticipated as being needed for all uses that can result in dietary and drinking water exposures. 14 Exposure studies are anticipated as being needed for following scenarios: open-pour liquids; open-pour wettable 

powders; application of preserved paints using brush/roller or airless sprayer; use of treated metalworking fluids; 

and trigger sprayer, wipe, and mop application of preserved cleaners. If labels are amended to require closed 

mixing/loading, then any required exposure study for open-pour liquid scenarios can likely be waived. If labels are 

amended to require water soluble packaging, then any required exposure study for open-pour wettable powder 

scenarios can likely be waived. It may be possible to use proprietary surrogate exposure data if data compensation 

issues are adequately addressed. 

15 Study is anticipated as being needed for following scenario: residential post application dermal and incidental oral 

exposure to floors cleaned with preserved household cleaning solutions. The anticipated DCI will provide that a 

protocol must be submitted for review and approval by the Agency prior to initiating this study. 

16 Study is anticipated as being needed for following scenarios: dietary exposures from countertops cleaned with 

preserved household cleaning solution; and dietary exposures from DBDCB treated paper products used in food 

packaging. The anticipated DCI will provide that a protocol must be submitted for review and approval by the 

Agency prior to initiating this study. In the absence of additional data, a default transfer factor of 100% would be 

expected to be used. 
Docket Number: EPA-HQ-OPP-2012-0342 

www.regulations.gov

19 of 23 

IV. Appendix A: Use Patterns – Dibromodicyanobutane 

Use Site Formulation/

EPA Reg. 

no. 

Method of 

Application 

Max. 

Application 

Rate 

Materials preservative 

Polyvinyl acetate, styrene-butadiene, methyl cellulose & 

acrylic, polyvinyl alcohol & hydroxyethyl cellulose, epoxy, 

polyester, dextrine based adhesives, casein based adhesives. 39967-28 

metered 

injection 

0.10-0.60% by 

weight 

Dispersed Pigments 

39967-28 

metered 

injection 

0.04-0.10% by 

weight 

Fiber Processing fluids 

39967-28 

metered 

injection 

0.20-1.20% by 

weight 

Joint cement 

39967-28 

metered 

injection 

0.20-0.40% by 

weight 

Latex emulsions 

39967-28 

metered 

injection 

0.04-0.20% by 

weight 

Metalworking fluids 

39967-28 

metered 

injection 

0.10-0.40% by 

weight 

Aqueous paints (including heating and air conditioning 

systems) 39967-28 

metered 

injection 

0.10-0.30% by 

weight 

Waxes, polishes and inks 

39967-28 

metered 

injection 

0.01-0.10% by 

weight 

Aqueous paints 

39967-29 

metered 

injection 

0.1-0.3% by 

weight 

Latex emulsions 

39967-29 

metered 

injection 

0.04-0.2% by 

weight 

Polyvinyl acetate, styrene-butadiene, methyl cellulose & 

acrylic 

Polyvinyl alcohol & hydroxyethyl cellulose. Epoxy, 

polyester. Dextrin. Casein 39967-29 

metered 

injection 

0.1-0.6% by 

weight 

Dispersed Pigments 

39967-29 

metered 

injection 

0.04-0.1% by 

weight 

Metalworking fluids 

39967-29 

metered 

injection 

0.1-0.4% by 

weight 

Waxes, polishes and inks 

39967-29 

metered 

injection 

0.01-0.1% by 

weight 

Joint cement 

39967-29 

metered 

injection 

0.2-0.4% by 

weight 

Fiber Processing fluids 

39967-29 

metered 

injection 

0.2-1.2% by 

weight 

Aqueous paints 

39967-32 

metered 

injection 

0.025-0.075% by 

weight 

Latex emulsions 

39967-32 

metered 

injection 

0.01-0.05% by 

weight 

Polyvinyl acetate, styrene-butadiene, methyl cellulose & 

acrylic 

Polyvinyl alcohol & hydroxyethyl cellulose. Epoxy, 

polyester. Dextrin. Casein 39967-32 

metered 

injection 

0.01-0.1$ by 

weight 

Titanium dioxide, calcium carbonate & clay 

39967-32 

metered 

injection 

0.01-0.025% by 

weight 

Metalworking fluids 

39967-32 

metered 

injection 

0.025-0.4% by 

weight 

Waxes, polishes and inks 39967-32 metered 0.01-0.1% by 
Docket Number: EPA-HQ-OPP-2012-0342 

www.regulations.gov

20 of 23 

Use Site Formulation/

EPA Reg. 

no. 

Method of 

Application 

Max. 

Application 

Rate 

injection weight 

Paste type, vinyl latex & protein 

Reconstituted powder type, vinyl latex & protein 39967-32 

metered 

injection 

0.05-0.2% by 

weight 

Aqueous paints 

39967-34 

metered 

injection 

0.1-0.3% by 

weight 

Latex emulsions 

39967-34 

metered 

injection 

0.04-0.2% by 

weight 

Polyvinyl acetate, styrene-butadiene, methyl cellulose & 

acrylic 

Polyvinyl alcohol & hydroxyethyl cellulose. Epoxy, 

polyester. Dextrin. Casein 39967-34 

metered 

injection 

0.1-0.6% by 

weight 

Dispersed Pigments 

39967-34 

metered 

injection 

0.04-0.1% by 

weight 

Metalworking fluids 

39967-34 

metered 

injection 

0.1-0.4% by 

weight 

Waxes, polishes and inks 

39967-34 

metered 

injection 

0.01-0.1% by 

weight 

Joint cement 

39967-34 

metered 

injection 

0.2-0.4% by 

weight 

Fiber Processing fluids 

39967-34 

metered 

injection 

0.2-1.2% by 

weight 

Starch, clay, calcium carbonate, titanium dioxide; paper 

coatings, high viscosity suspensions; e.g., polymers, sizing 

solutions; adhesives such as polyvinyl alcohol/polyvinyl 

acetate based adhesives; starch based adhesives; dextrin based 

adhesives. 39967-36 

metered 

injection 

0.04-1.0% by 

weight 

Starch, clay, calcium carbonate, titanium dioxide; paper 

coatings, high viscosity suspensions; e.g., polymers, sizing 

solutions; adhesives such as polyvinyl alcohol/polyvinyl 

acetate based adhesives; starch based adhesives; dextrin based 

adhesives. 39967-37 

metered 

injection 

0.04-1.0% by 

weight 

Aqueous paints and Coatings (including heating and air 

conditioning systems) 39967-38 

metered 

injection 

800-3000ppm 

Dishwashing liquids, furniture and 

floor waxes and polishes, cleaners and treatment products and 

over-the counter inks. 39967-38 

metered 

injection 

500-8000ppm 

Starch, epoxy, polyester, polyvinyl acetate, styrene butadiene, 

methyl cellulose, acrylic, polyvinyl alcohol, hydroxyethyl 

cellulose, dextrin and casein. 39967-38 

metered 

injection 

500-8000ppm 

Joint cement 

39967-38 

metered 

injection 

2000-8000ppm 

Paints and coatings, adhesives and plastics. Starch, clay, 

calcium carbonate or titanium dioxide; paper coatings, high 

viscosity suspensions, polymers, sizing solutions. 39967-38 

metered 

injection 

400-9000ppm 

Metalworking fluids 

39967-38 

metered 

injection 

500-4000ppm 

Dishwashing liquids, furniture and 

floor waxes and polishes, cleaners and treatment products and 

over-the counter inks. 39967-38 

metered 

injection 

500-4000ppm 

Non-apparel fiber applications and canvas 

39967-38 

metered 

injection 

0.2-1.2% by 

weight (2000-

12000ppm) 
Docket Number: EPA-HQ-OPP-2012-0342 

www.regulations.gov

21 of 23 

Use Site Formulation/

EPA Reg. 

no. 

Method of 

Application 

Max. 

Application 

Rate 

Aqueous paints and Coatings. 

39967-39 

metered 

injection 

500-4000ppm 

Polyvinyl acetate, acrylic, vinyl acrylic and styrene butadiene. 

39967-39 

metered 

injection 

500-8000ppm 

Dispersed Pigments 

39967-39 

metered 

injection 

500-2000ppm 

Dishwashing liquids, furniture and 

floor waxes and polishes, cleaners and treatment products and 

over-the counter inks. 39967-39 

metered 

injection 

500-8000ppm 

Joint cement 

39967-39 

metered 

injection 

2000-8000ppm 

Metalworking fluids 

39967-39 

metered 

injection 

500-4000ppm 

Printer, copier and computer printer inks 

39967-39 

metered 

injection 

10-2000ppm 

Polyvinyl acetate, acrylic, vinyl acrylic, alkyd 

modified acrylic & alkyl modified vinyl acrylic 39967-40 

metered 

injection 

0.125-0.375% by 

weight 

Polyvinyl acetate, acrylic, vinyl acrylic & styrene-butadiene 

39967-40 

metered 

injection 

0.05-0.25% by 

weight 

Potyvinyl acetate, Styrene-butadiene, methyl cellulose & 

acrylic, hydroxyethyl cellulose, Epoxy, polyester, Dextrin, 

Casein 39967-40 

metered 

injection 

0.05-0.375% by 

weight 

Clay, titanium dioxide & calcium carbonate 

39967-40 

metered 

injection 

0.05-0.125% by 

weight 

Metalworking fluids 

39967-40 

metered 

injection 

0.125-0.5% by 

weight 

Waxes, polishes and inks 

39967-40 

metered 

injection 

0.05-0.5% by 

weight 

Joint cement 

39967-40 

metered 

injection 

0.25-0.5% by 

weight 

Polyvinyl acetate, styrene-butadiene, methyl cellulose & 

acrylic, polyvinyl alcohol & hydroxyethyl cellulose, epoxy, 

polyester, dextrine based adhesives, casein based adhesives. 39967-110 

metered 

injection 

0.10-0.60% by 

weight 

Dispersed Pigments 

39967-110 

metered 

injection 

0.04-0.10% by 

weight 

Fiber Processing fluids 

39967-110 

metered 

injection 

0.20-1.20% by 

weight 

Joint cement 

39967-110 

metered 

injection 

0.20-0.40% by 

weight 

Latex emulsions 

39967-110 

metered 

injection 

0.04-0.20% by 

weight 

Metalworking fluids 

39967-110 

metered 

injection 

0.10-0.40% by 

weight 

Polyvinyl acetate, styrene-butadiene, methyl cellulose & 

acrylic, polyvinyl alcohol & hydroxyethyl cellulose, epoxy, 

polyester, dextrine based adhesives, casein based adhesives. 39967-111 

metered 

injection 

0.10-0.60% by 

weight 

Dispersed Pigments 

39967-111 

metered 

injection 

0.04-0.10% by 

weight 

Fiber Processing fluids 

39967-111 

metered 

injection 

0.20-1.20% by 

weight 

Joint cement 

39967-111 

metered 

injection 

0.20-0.40% by 

weight 
Docket Number: EPA-HQ-OPP-2012-0342 

www.regulations.gov

22 of 23 

Use Site Formulation/

EPA Reg. 

no. 

Method of 

Application 

Max. 

Application 

Rate 

Latex emulsions 

39967-111 

metered 

injection 

0.04-0.20% by 

weight 

Metalworking fluids 

39967-111 

metered 

injection 

0.10-0.40% by 

weight 

Paints, coatings and stains 

39967-111 

metered 

injection 

0.10-0.30% by 

weight 

Waxes, polishes and inks 

39967-111 

metered 

injection 

0.01-0.10% by 

weight 

Paper Auxiliaries/Additives 

Paper Slurries 

Fiber Processing Fluids 39967-117 

metered 

injection 

0.20-1.7% by 

weight 

Polyvinyl acetate, styrene-butadiene, methyl cellulose & 

acrylic, polyvinyl alcohol & hydroxyethyl cellulose, epoxy, 

polyester, dextrine based adhesives, casein based adhesives. 39967-117 

metered 

injection 

0.0125-0.6% by 

weight (125-

6000ppm) 

Biopolymers (e.g. Xanthan), Caulking Materials, Mastics, 

Ceramic Glazes 

Chemical Cleaning Solutions, Cleaning Solutions, Concrete 

and Masonry, Additives, Concrete, Fire Extinguishing 

Medium, Photographic Gelatins, Plasters, Polishes, Rubber 

Systems, Tints, Wax Emulsions, Joint cements 39967-117 

metered 

injection 

 

Metalworking fluids concentrates 

39967-117 

metered 

injection 

0.2-0.5 gallons 

per 1000 gallons 

Alkyd Resin-Based Systems, Casein-Systems, Latex-Based 

Systems, Oil-Containing Systems, Synthetic Resin 

Dispersions 39967-117 

metered 

injection 

0.0125-0.6% by 

weight (125-

6000ppm) 

Calcium Carbonate Slurries, Carbon Black Pigment Slurries, 

Clay Slurries 

Iron Oxide Pigment Slurries, Kaolin Slurries, Organic Dyes 

and Pigment Slurries, Other Filler Suspensions 

Starch Slurries, Inks 39967-117 

metered 

injection 

0.0125-0.6% by 

weight (125-

6000ppm) 

Acrylic-Systems, Other Polymer Dispersions, PolyesterBased Systems, Polyurethane-Based Systems, Polyvinyl 

acetate (PVA) Systems, Styrene Butadiene Systems, Vinyl 

Acrylic-Based Systems, Latex Emulsions 39967-117 

metered 

injection 

0.0125-0.6% by 

weight (125-

6000ppm) 

Industrial processes and water systems 

Pulp, paper and paperboard systems 

39967-36 

metered 

injection 

0.08-0.4lbs/ton. 

Pulp, paper and paperboard systems 

39967-37 

metered 

injection 

0.08-0.4lbs/ton. 

Cooling water tower systems 

39967-38 

metered 

injection 

500-8000ppm 

Pulp, paper and paperboard systems 

39967-38 

metered 

injection 

0.05-0.4 lbs/ton 

Pulp, paper and paperboard systems 

39967-40 

metered 

injection 

0.02-0.1% by 

weight 

Non-marine enhanced oil recovery systems, oil field water, 

polymer of micellar floods, water-disposal systems or other 

oil field water systems 

59106-2 

metered 

injection 

3-27lbs per 

20,000 gal water, 

1-4 times per 

week 

Drilling muds 

59106-2 

metered 

injection 

3-27lbs per 

20,000 gal water, 

1-4 times per 
Docket Number: EPA-HQ-OPP-2012-0342 

www.regulations.gov

23 of 23 

Use Site Formulation/

EPA Reg. 

no. 

Method of 

Application 

Max. 

Application 

Rate 

week 

Water floods 

59106-2 

metered 

injection 

3-27lbs per 

20,000 gal water, 

1-4 times per 

week 

Non-marine enhanced oil recovery systems, oil field water, 

polymer of micellar floods, water-disposal systems or other 

oil field water systems 59106-3 

metered 

injection 

0.8-7.6 lbs per 

100 barrels of 

water 

Completion and workover fluids 

59106-3 

metered 

injection 

0.8-7.6 lbs per 

100 barrels of 

water 

Drilling muds/packer fluids59106-3 metered 

injection 

0.8-7.6 lbs per 

100 barrels of 

water 

Water floods 

59106-3 

metered 

injection 

0.8-7.6 lbs per 

100 barrels of 

water 

Industrial processes and water systems 

39967-117 

metered 

injection 

0.00095-0.095 

gallons per 1000 

gallons of water 

Cooling water tower systems 

39967-117 

metered 

injection 

0.00095-0.095 

gallons per 1000 

gallons of water 

Pulp, paper and paperboard systems 

39967-117 

metered 

injection 

0.15-0.50 lbs per 

ton of pulp or 

paper 

Oil field water, polymer of micellar floods, water-disposal 

systems or other oil field water systems 

39967-117 

metered 

injection 

0.1-6.4 gallons 

per 2400 barrels 

of water (1-80 

ppm) 

Formulation Use 

Only for formulation into a microbiocide / microbiostat / 

bacteriostat for use as an additive for latex and oil paints, 

emulsions, metalworking cutting fluids, secondary oil 

recovery injection waters, drilling muds, industrial adhesives, 

dispersed pigments, metalworking fluids, waxes & polishes, 

inks, and joint cements. 39967-41 

 

Only for formulation into a microbiocide / microbiostat / 

bacteriostat for use as an additive for latex and oil paints, 

emulsions, industrial adhesives, dispersed pigments, 

metalworking fluids, waxes & polishes, inks, and joint 

cements. 39967-62