United States Chemical Safety September 2012 

Environmental Protection and Pollution Prevention 

Agency (7510P) 

 

Didecyl Dimethyl Ammonium Carbonate and 

Didecyl Dimethyl Ammonium Bicarbonate 

(DDACB) 

Summary Document: 

Registration Review: Initial Docket 

September 2012 

 

Docket Number: EPA-HQ-OPP-2012-0651 

www.regulations.gov

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TABLE OF CONTENTS 

Didecyl Dimethyl Ammonium Carbonate and Didecyl Dimethyl Ammonium Bicarbonate 

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

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

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

III. Summary of Anticipated Data Requirements ..............................................................18 

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 Didecyl dimethyl ammonium carbonate (DDA 

Carbonate) and Didecyl dimethyl ammonium bicarbonate (DDA Bicarbonate). 

September 13, 2012 

2. DIDECYL DIMETHYL AMMONIUM CARBONATE/BICARBONATE (DDACB; 

BARDAC 22C50): Human Health Assessment Scoping Document in Support of 

Registration Review. September 6, 2012 

Additional supporting documents for the Didecyl Dimethyl Ammonium Carbonate And Didecyl 

Dimethyl Ammonium Bicarbonate Case may be found in the registration review docket EPA-HQOPP-2012-0651 located on the internet at www.regulations.gov. 
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Didecyl Dimethyl Ammonium Carbonate and Didecyl Dimethyl Ammonium Bicarbonate

(DDACB)

Registration Review Team

Human Health & Environmental Effects

Michelle Centra 

Nathan Mottl 

Jonathan Chen 

William Hazel 

Srinivas Gowda 

James Breithaupt 

Risk Management

Wanda Henson 

Lance Wormell 

Office of General Counsel

Philip Ross 
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I. Preliminary Work Plan -- Didecyl Dimethyl Ammonium Carbonate and Didecyl 

Dimethyl Ammonium Bicarbonate (DDACB) 

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 Didecyl Dimethyl Ammonium Carbonate and Didecyl Dimethyl Ammonium 

Bicarbonate Case (DDACB). 

The Didecyl Dimethyl Ammonium Carbonate and Didecyl Dimethyl Ammonium Bicarbonate - 

(Case 5014) consist of two chemical moieties (a carbonate and a bicarbonate) combined to make 

one active ingredient under PC Code 069208. 

The first product containing Didecyl Dimethyl Ammonium Carbonate and Didecyl Dimethyl 

Ammonium Bicarbonate (DDACB) as an active ingredient was registered in the United States in 

1995. Currently, there are 11 products containing DDACB as an active ingredient registered with 

EPA. Products containing DDACB are registered for use as hard non porous surface 

disinfectants and materials preservatives for use in/on food handling/storage establishments 

premises and equipment; industrial process and water systems; medical premises and equipment; 

residential and public access premises; and as a wood preservative. The are no inert uses and no 

tolerances. 

DDACB is exempt from the requirement for a tolerance per 40 CFR Part 180.940(a) for use: in 

food-contact surfaces in public eating places, dairy-processing equipment, and food processing 

equipment and utensils when the end-use concentration does not to exceed 400 ppm of active 

quarternary ammonium compound. The Agency published on August 22, 2012 a final rule that 

changed the level from 240 ppm to 400 ppm of active quarternary ammonium compound. 
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A Reregistration Eligibility Decision (RED) was not completed for DDACB because it was 

registered after November 1, 1984. 

Documents associated with the registration review of Didecyl Dimethyl Ammonium Carbonate 

and Didecyl Dimethyl Ammonium Bicarbonate can be viewed at www.regulations.gov in docket 

EPA-HQ-OPP-2012-0651. Below is a summary of the issues relevant to this registration review 

case. 

Quaternary Ammonium Compounds

DDACB is a part of the Group I class (cluster I grouping) in PR Notice 88-2, i.e. it is a member 

of the aliphatic dimethyl dialkyl quaternary ammonium compounds. 

Didecyl dimethyl ammonium chloride (DDAC) which is being reevaluated separately under case 

#3003 is the representative member of the Group I class of quaternary ammonium compounds 

and hazard data generated for DDAC is considered to be representative of the hazard associated 

with all chemicals assigned to this class of quaternary ammonium chemicals, including DDACB. 

Consequently, toxicity studies conducted with DDAC or other Group I class quaternary 

ammonium compounds can be bridged into a single mammalian toxicity data base. The DDACB 

risk assessments will be based on studies using the DDAC/DDACB combined database. 

A Reregistration Eligibility Decision (RED) document has been issued for DDAC and the 

Agency intends to incorporate the available RED data as well as any additional data received in 

response to the DDAC case post-RED Data Call-in (DCI) into the risk assessments to be 

performed for registration review of DDACB. 

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 DDACB. The Agency 

anticipates the need to conduct a human health risk assessment. The Agency anticipates needing 

additional data for use in conducting the registration review for DDACB. 

Ecological Risk: 

 No ecological risk assessment has been performed for DDACB. However, an ecological 

risk assessment for DDAC was conducted in support of the 2006 DDAC RED. 

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

species determination for DDACB. The ecological risk assessment planned during 

registration review will allow the Agency to determine whether DDACB 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. 
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 The Agency anticipates the need to require the following additional ecological data for 

use in the registration review of DDACB. 

850.1730 -- Oyster Bioconcentration study 

850.3020 -- Honey bee acute contact study 

850.3030 -- Toxicity of residues to honeybees 

850.3300 -- Activated Sludge Respiration Inhibition 

 The Agency does not anticipate the need to require additional environmental fate data for 

this registration review case at this time. 

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

Ecological Effects Scoping Document in Support of Registration Review of Didecyl 

dimethyl ammonium carbonate (DDA Carbonate) and Didecyl dimethyl ammonium 

bicarbonate (DDA Bicarbonate), located in the docket. 

Human Health Risk: 

 No human health risk assessment has been performed for DDACB. However, a human 

health risk assessment was conducted for DDAC in support of the 2006 DDAC RED. 

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

for use in the registration review of DDACB. 

870.3465 -- 90-day inhalation toxicity (rat) 

875.1100 -- Dermal outdoor exposure 

875.1200 -- Dermal indoor exposure 

875.1300 -- Inhalation outdoor exposure 

875.1400 -- Inhalation indoor exposure 

875.1600 -- Application exposure data reporting and calculations 

875.1700 -- Product use information (Handler) 

875.2700 -- Product use information (Post application) 

 For more information, please refer to DIDECYL DIMETHYL AMMONIUM 

CARBONATE/BICARBONATE (DDACB; BARDAC 22C50): Human Health Assessment 

Scoping Document in Support of Registration Review. located in the docket. 

Product Chemistry: 

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

 this registration review case at this time. 

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

Ecological Effects Scoping Document in Support of Registration Review of Didecyl 

dimethyl ammonium carbonate (DDA Carbonate) and Didecyl dimethyl ammonium 

bicarbonate (DDA Bicarbonate), located in the docket. 
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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 its most recent reregistration decision for DDAC, EPA reviewed 

these data and selected the most sensitive endpoints for relevant risk assessment scenarios from 

the existing hazard database. However, as required by FFDCA section 408(p), DDACB 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. DDACB 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 call-ins, 

requiring the submission of EDSP screening assays for DDACB. 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 Didecyl Dimethyl 

Ammonium Carbonate and Didecyl Dimethyl Ammonium Bicarbonate (DDACB) registration 

review: 
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Anticipated Schedule

Activities Estimated Month/Year

Phase 1: Opening the docket 

Open Docket and 60-Day Public Comment Period for PWP September 2012

Close Public Comment Period November 2012 

Phase 2: Case Development 

Develop Final Work Plan (FWP) March 2013 

Issue DCI March 2014 

Data Submission March 2016 

Open 30-Day Public Comment Period for Preliminary Risk 

Assessments 

September 2017 

Close Public Comment Period for Preliminary Risk Assessments October 2017 

Phase 3: Registration Review Decision 

Open 60-Day Public Comment Period for Proposed Reg. Review 

Decision 

March 2018 

Close Public Comment Period for Proposed Reg. Review Decision May 2018 

Final Decision and Begin Post-Decision Follow-up September 2018 

Total (years) 6 

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 Didecyl Dimethyl Ammonium Carbonate 

and Didecyl Dimethyl Ammonium Bicarbonate 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:

DDACB 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 DDACB, 

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. 
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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 DDACB 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. 

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. 
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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 

Didecyl Dimethyl Ammonium Carbonate And Didecyl Dimethyl Ammonium Bicarbonate 

(DDACB) 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. Pre-submission 

consultation with the Agency is encouraged. 

Additional Information:

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 November 2012, the Agency will review and respond 

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

Dimethyl Ammonium Carbonate And Didecyl Dimethyl Ammonium Bicarbonate (DDACB) 

case. 
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II. Fact Sheet 

Background Information:

 Active Ingredient: Didecyl Dimethyl Ammonium Carbonate and Didecyl Dimethyl 

Ammonium Bicarbonate (DDACB) 

 Case number: 5014 

 PC Code: 069208 

 CAS numbers: 148788-50-0 and 148812-65-1 

 Technical registrants: Lonza 

 First approved for use in a registered product: 1995 

 There are no inert uses for this chemical and no tolerances. DDACB is exempt from the 

requirement for a tolerance per 40 CFR Part 180.940(a) for use: in food-contact surfaces 

in public eating places, dairy-processing equipment, and food processing equipment and 

utensils when the end-use concentration does not to exceed 400 ppm of active 

quarternary ammonium compound. The Agency published on August 22, 2012 a final 

rule that changed the level from 240 ppm to 400 ppm of active quarternary ammonium 

compound. 

 Antimicrobials Division Chemical Review Manager (CRM): Wanda Henson, 

Henson.Wanda@epa.gov

 Antimicrobials Division Product Manager (PM): Velma Noble, Noble.Velma@epa.gov

 Chemical Structure: 

Use & Usage Information:

 Products containing didecyl dimethyl ammonium carbonate and didecyl dimethyl 

ammonium bicarbonate (DDACB) are registered for use as a hard non porous surface 

disinfectant and a material preservative: in/on food handling/storage establishments 

premises and equipment; industrial process and water systems; medical premise and 

equipment; residential and public access premises; as a wood preservative. 

Recent/Pending Regulatory Actions:

 There are currently three (3) pending registrations for this chemical.

Ecological Risk Assessment Status:
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 The Agency has not conducted a risk assessment that supports a complete endangered species 

determination for DDACB. The ecological risk assessment planned during registration 

review will allow the Agency to determine whether DDACB’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 most recent ecological risk assessment for DDAC was conducted in support of the 

2006 DDAC RED. In the RED, EPA specified labeling language to reduce environmental 

exposure and risk resulting from DDAC use in once-through cooling water towers and 

anti-sapstain wood.

 For registration review, an ecological risk assessment will be conducted for uses that have 

the potential to discharge to waste water treatment plants with releases to surface water. 

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

use in the registration review of DDACB. 

 850.1730 -- Oyster Bioconcentration study 

 850.3020 -- Honey bee acute contact study 

 850.3030 -- Toxicity of residues to honeybees 

 850.3300 -- Activated Sludge Respiration Inhibition 

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

Document in Support of Registration Review of Didecyl dimethyl ammonium carbonate 

(DDA Carbonate) and Didecyl dimethyl ammonium bicarbonate (DDA Bicarbonate), 

located in the docket, for a detailed discussion of the ecological risk assessments. 

Human Health Risk Assessment Status:

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

Ammonium Carbonate and Didecyl Dimethyl Ammonium Bicarbonate. Please refer to 

DIDECYL DIMETHYL AMMONIUM CARBONATE/BICARBONATE (DDACB; BARDAC 

22C50): Human Health Assessment Scoping Document in Support of Registration Review.

located in the docket, for a detailed discussion of the human health risk assessment. 

Hazard Characterization: 

 DDACB was assigned a Toxicity Category II in an acute oral toxicity study in rats and 

assigned a Toxicity Category I in a primary dermal irritation study in rabbits. A photo 

allergyl sensitization study (with and without UV irradiation) in guinea pigs conducted 

with the product, BARDAC 22C50 (50% a.i.), is negative for dermal sensitization; 

however the photoallergic response results for this study were equivocal. The Agency 

has granted data waivers for acute dermal toxicity, primary eye irritation and acute 

inhalation toxicity because of the corrosive nature of the active ingredient, DDACB. 

Based on the results of the primary skin irritation study in rabbits, the BARDAC 22C50 
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product and other products containing 50% DDACB active ingredient were assigned an 

overall Toxicity Category I (corrosive). 

 There is no available repeat exposure inhalation toxicity study to demonstrate the types of 

adverse effects that may be manifested via this route of exposure or the dose(s) at which 

respiratory-specific adverse effects may occur. 

 DDAC is not likely to be a human carcinogen based on (1) negative results for all DDAC 

mutagenicity testing and (2) lack of evidence of carcinogenicity in the rat and mouse 

carcinogenic studies 

Dietary (Food and Water): 

 DDACB residues can migrate to food coming into contact with the treated surfaces. 

 EPA considered dietary exposure to the higher proposed DDACB use dilution (400 ppm) 

as well as to all existing aliphatic dialkyl dimethyl quaternary ammonium salts (DDAC, 

etc.) uses. The Agency assessed acute and chronic dietary exposures from the use of 

DDACB as a disinfectant and food-contact sanitizer on utensils, countertops, and 

food/beverage processing equipment using FDA models and the Indirect Dietary Residue 

Exposure Assessment Model (IDREAM). A 100% residue transfer rate was assumed for 

the food bottling/packaging use because of the potentially long contact time of food with 

treated surfaces. Acute and chronic dietary risks were estimated to be 11% (adult males 

(13+ yr)), 12% (adult females (13-49 yr)), and 70% (children (1-2 yr)) of the aPAD and 

cPAD both of which are 0.1 mg/kg/day. 

 DDACB is classified as a surfactant possessing a charged moiety (N+) and components 

that are nonpolar/lipophilic (the two 10-carbon alkyl groups). These components provide 

DDACB with properties allowing it to adsorb both to clay particles (via cation exchange) 

and organic matter (via hydrophobic attraction of the two alkyl groups). It adsorbs rapidly 

to soil and sediments but is not readily desorbed. It also binds to cellulose and lignin 

(organic matter) thus permitting its use as a wood preservative. Because of its strong 

adsorption to soils, DDACB is not expected to contaminate surface and ground waters or 

to reach waste water treatment plants if it were discharged from industrial water systems. 

As a result, contamination of drinking water with DDACB residues is expected to be 

negligible. 

Residential: 

 Residential exposure and risk to DDAC was assessed in the 2006 DDAC RED. Many of 

the uses of DDAC are similar to DDACB. The residential-use products include 

disinfectants, sanitizers, fungicide, mildewstats, and deodorizers. DDACB is also used as 

a material preservative in paints and laundry detergents. Unit exposure data for liquid 

pour, mopping, wiping, aerosol spray, airless sprayer, and brush/roller are needed before 

new handler risk assessments can be conducted. 
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 The residential post-application scenario that will be considered for the registration 

review include exposure to residue from hard surfaces (i.e., floors) and carpets that have 

been mopped, sprayed or cleaned with a product containing DDACB; incidental 

ingestion from hand-to-mouth exposure from countertops and pressure treated decks; 

mouthing of laundered clothes; and dermal exposure from treated decks, playsets and 

floors. DDACB has a low vapor pressure; therefore, there is no concern for potential 

vapor inhalation exposure. 

 There are also uncertainties associated with the assumptions used in the post-application 

assessment in support of the DDAC RED (i.e. percent transfer of residues from cleaned 

floor, leaching of residues from the laundered textiles, etc) that will also need to be 

addressed as they relate to DDACB. Upon a submission of the necessary information, a 

post application exposure assessment will be completed for registration review, as 

appropriate, additional scenarios will be incorporated into the revised aggregate 

assessment. 

Aggregate: 

 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-occupational pesticide exposures. Upon a reevaluation and selection of 

toxicological endpoints, combined with the revised dietary and residential exposure 

assessment expected as a part of this registration review case, an aggregate assessment 

will need to be conducted for DDACB. 

Occupational: 

 Worker exposure to DDACB is expected to occur through the use of DDACB-containing 

products in several industrial and commercial settings. Short-term and intermediate-term 

from contact will be assessed. A recent risk assessment has reassessed the uses for 

agricultural premises; commercial, institutional, and industrial premises; medical 

premises; and food handling (D400391, D340425). The DDAC RED also covered these 

use patterns as well as industrial processes and water systems and wood treatment 

(USEPA, 2006). Recent registration occupational and residential exposure assessments 

have also assessed wood preservative uses and paints (D321231, D24130). 

 The Agency intends to review and consider data received in response to the DDAC postRED DCI (anticipated issuance in FY 2012) and incorporate the new data into the risk 

assessments. The Agency anticipates needing additional data for some use patterns that 

were not covered in the DDAC RED. These uses include material preservatives such as 

paint, metal working fluids and the Agency expects to issue a separate registration review 

DCI for these studies. During reregistration the Agency received several exposure studies 

from the registrant and intends to review these studies during registration review (see 

reference section for some of the existing data submissions). 

 The occupational exposure assessment utilized surrogate databases, for which 

uncertainties have been identified. A review of the registered labels identifed additional 
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occupational exposure scenarios that will need to be assessed. Based on these additional 

scenarios, occupational risk assessments will be required to support registration review of 

DDACB. 

Cumulative: 

 EPA does not have, at this time, available data to determine whether DDACB has a 

common mechanism of toxicity with other substances or how to include this pesticide in 

a cumulative risk assessment. This Registration Review assumes that DDACB does not 

have a common mechanism of toxicity with other substances when used as an 

antimicrobial as registered. 

Incidents:

Ecological: 

 No DDACB ecological incidents have been reported in the Ecological Incident 

Information System (EIIS) database. 

Human Health: 

 EPA reviewed available incident information for all quarternary ammonium compounds, 

including DDACB, for the human incidents associated with exposure to end-use products 

containing these chemicals reported in the OPP Incident Data System (IDS), California 

Department of Pesticide Regulation (1982-2004), National Pesticide Telecommunications 

Network (NPTN) and Published Incident Reports. Dermal, ocular and inhalation are the 

primary routes of exposure. Most of the incidences are related to irritation. The 

symptoms associated with eye are commonly reported for quaternary ammonium 

compound exposures. Allergic type reactions have also been reported in some incidents. 

Tolerances and International Harmonization: 

 DDACB is exempt from the requirement for a tolerance per 40 CFR Part 180.940(a) for 

use: in food-contact surfaces in public eating places, dairy-processing equipment, and 

food processing equipment and utensils when the end-use concentration does not to 

exceed 400 ppm of active quarternary ammonium compound. The Agency published on 

August 22, 2012 a final rule that changed the level from 240 ppm to 400 ppm of active 

quarternary ammonium compound. 

Data Call-In Status:

 There are currently no outstanding Data Call-In requirements for this chemical. 

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 
Docket Number: EPA-HQ-OPP-2012-0651 

www.regulations.gov

17 of 19 

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. 

Table 1. Registered Products (DDACB) 

Registration # Registration Name Company Name Formulation Type % A.I. 

1677-231 Ster-Bac Ecolab, Inc. Soluble Concentrate 7.5 

3008-90 ORD-X732 Osmose Inc. Ready-To-Use 12.8 

3008-94 ORD-X280 Osmose Inc. Soluble Concentrate 16.66 

3008-104 Sustain 20CQ Osmose Inc. Flowable 

Concentrate 12.8 

6836-236 Bardac 22C50 Lonza Inc. Formulation 

Intermediate 50 

6836-304 Carboquat WP-50 Lonza Inc. Soluble Concentrate 50 

6836-323 Carboserve Lonza Inc. Soluble Concentrate 50 

6836-327 Carbosan Lonza Inc. Soluble Concentrate 50 

6836-330 Carboquat CM-50 Lonza Inc. Soluble Concentrate 50 

6836-331 Carbosan 20 Lonza Inc. Soluble Concentrate 20 

6836-332 Carbosan 7.5 Lonza Inc. Soluble Concentrate 7.5 
Docket Number: EPA-HQ-OPP-2012-0651 

www.regulations.gov

18 of 19 

III. Summary of Anticipated Data Requirements – Didecyl Dimethyl Ammonium 

Carbonate And Didecyl Dimethyl Ammonium Bicarbonate (DDACB) 

The table below summarizes anticipated data needs for the Didecyl Dimethyl Ammonium 

Carbonate And Didecyl Dimethyl Ammonium Bicarbonate 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 Didecyl dimethyl ammonium carbonate 

(DDA Carbonate) and Didecyl dimethyl ammonium bicarbonate (DDA Bicarbonate), and 

DIDECYL DIMETHYL AMMONIUM CARBONATE/BICARBONATE (DDACB; BARDAC 

22C50): Human Health Assessment Scoping Document in Support of Registration Review.. 

Table 2. Summary of Anticipated Data Requirements – DIDECYL DIMETHYL 

AMMONIUM CARBONATE And DIDECYL DIMETHYL AMMONIUM 

BICARBONATE (DDACB) 

Guideline 

Number Anticipated Data Requirement Test Material 

Estimated Timeframe 

(Measured in months from 

DCI Receipt) 

850.1730 Oyster bioconcentration study TGAI 24 

850.3020 Honey bee acute contact study TGAI 12 

850.3030 Toxicity of residues to honeybees TGAI 12 

850.3300 Activated Sludge Respiration Inhibition TGAI 24 

870.3465 90-day inhalation toxicity(rat) TGAI 24 

875.1100 Dermal outdoor exposure TGAI 24 

875.1200 Dermal indoor exposure TGAI 24 

875.1300 Inhalation outdoor exposure TGAI 24 

875.1400 Inhalation indoor exposure TGAI 24 

875.1600 Application exposure data reporting and 

calculations TGAI 12 

875.1700 Product use information (Handler) TGAI 12 

875.2700 Product use information (Post 

Application) TGAI 12 

 
Docket Number: EPA-HQ-OPP-2012-0651 

www.regulations.gov

19 of 19 

IV. Appendix A 

Food Handling/storage establishments premises and equipment

Beer fermentation and storage tanks 

Dairy processing equipment 

Egg washing treatments 

Entryway sanitizing systems 

Food processing equipment, Conveyors 

Hard non-porous surfaces in restaurants 

Sanitary filling equipment, ice machines, soft serve and frozen beverage dispensing 

equipment 

Waterproof gloves, shoe baths 

Industrial processes and water systems

Gas/oil recovery systems 

Hydrotesting pipelines or vessels 

Pipeline pigging and scraping operations 

Materials Preservatives

Aerosol cans, petroleum products, cleaning products, and cleaning, sanitizing, and 

disinfecting wipes for use on hard non-porous, surfaces 

Paints and decorative coatings 

Metalworking fluids 

Paper and Paperboard 

Metalworking Cutting Fluids 

Medical premises and equipment

Hard non-porous surfaces in Hospitals, nursing homes and dentist offices, etc. 

Salon / barber tools and instruments 

Ultrasound transducers, probes, mammography compressor plates 

Residential and public access premises

Air freshener 

Hard non-porous surfaces in household/domestic dwellings 

Laundry 

Holding tanks, gray water tanks. 

Wood Preservatives

Pressure treatment