### MEMORANDUM

SUBJECT:

FROM:

THRU:

TO: OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION 

### September 13, 2012

Product Chemistry, Environmental Fate, and Ecological Effects Scoping Document in Support ofRegistration Review ofDidecyl dimethyl ammonium carbonate (DDA Carbonate) and Didecyl dimethyl ammonium bicarbonate (DDA Bicarbonate)

PC Code: 069208 for Mixture of DP Barcode: 401751 DDA Carbonate and DDABicarbonate Decision No.: 464738 Registration Nos.: None. Petition No(s).: NA Regulatory Action: Ecological Environmental Scoping Document for Registration Review RiskAssessment Type: Multiple Case No.: 5014 chemical TXRNo.:NA CAS Nos.: DDACarbonate: 148788-55-0 DDA Bicarbonate: 148812-65-1 MRlD Nos.: See Tables 3 & 4 40 CFR: 180

.940(a), Tolerance Exemption and pages 4, 7, 8, & 9.



### Srinivas Gowda, M.S. Microbiologist/Science

### Coordinator**S)!'~·..;~~** Donna M. Randall, M.S., Senior Biologist

. James Breithaupt, M.S. Agronomist

## Cv~ 

## .**/L~** 

# .v L

.. ;;/ Risk Assessment and Science Support BrJC' h

## (RAS**ssrv ~**  Antimicrobials Division (751OP) 

### <'A

### //~ StevenWeiss, Acting Branch Chief**~** VC/.4- 

### Risk Assessment and Science Support Branch (RASSB) Antimicrobials Division (7510P)

Wanda Henson, Chemical Review Manager Regulatory Management Branch II Antimicrobials Division (7510P)

Page 1 of 17

### EXECUTIVE SUMMARY
Didecyl dimethyl ammonium carbonate (DDACarbonate) and didecyl dimethyl ammonium bicarbonate (DDA Bicarbonate) are quaternary ammonium compounds. Bardac® 22C50 is the trade name for the mixture ofDDA Carbonate and DDA Bicarbonate. Bardac 22C50 is registered for use in the formulation ofwood preservatives, sapstain control, hardsurface disinfectants, nonfood contact surface sanitizers, food contact surface sanitizers, oilfield biocide and as a material preservative (metal working fluids, paints, household and industrial, cleaning and related products packaged in aerosol cans). Bardac® 22C50 is not for use in marine and estuarine oil fields. In

### water DDA Carbonate and DDA Bicarbonate dissociate into DDA cations and carbonate/bicarbonate anions. Forthe registered use patterns the exposure pathway ofconcern is the aquatic environment and the Agency is conducting its fate and environmental assessment on the DDA cation.

The environmental fate ofdidecyl dimethyl ammonium carbonates (DDA carbonatesincludes both carbonate and bicarbonate) is essentially the same as didecyl dimethyl ammonium chloride (DDAC, PC Code 069149), and therefore the data for DDAC were used to bridge to and help satisfy DDA carbonates environmental fate data requirements

. DDA carbonates will disassociate upon contact with water to form the DDA cation and the carbonate/bicarbonate anions, and the cation will sorb nearly irreversibly to soil and sediment because ofthe negative charge associated with soil and sediment. Based on DDAC studies, the DDA cation is expected to be stable to hydrolysis and photodegradation in water and essentially stable to aquatic metabolism. However, DDA in activated sludge was found to bereadily biodegradable. Except for an oyster bioconcentration study for DDA, all fate data needed to conduct an ecological risk assessment for DDA carbonate uses resulting in discharge ofwaste water from treatmentplants

are fulfilled.

TheDDA carbonates ecological risk assessment will be based on studies using Bardac 22C50 as the test chemical and when not available, data onDDAC as the test chemical will be used. DDAC is similarto Bardac 22C50 and was determined to be acceptable as a surrogate compound after an extensive review ofthe two compounds' chemical and toxicological properties. Several Acceptable ecological studies were available in the OPP Agency files from past registrations. These included bird studies, both dietary and acute, acute freshwater fish and freshwater invertebrate toxicity studies, acute toxicity studies to estuarine/marine fish, acute toxicity studies to estuarine/marine invertebrates, a chronic toxicity fish early-life stage study, a chronic freshwater invertebrate study, acute toxicity studies, both freshwater and estuarine, of treated sediment to invertebrates, toxicity studies to Alga and 

### Lemna gibba. All ofthese studies will be available for an ecological risk assessment. A honeybee acute contact study, toxicity of residues to honeybees, and an activated sludge respiration inhibition study is needed for DDA.

An 

### ecological risk assessment will be conducted for those premise and equipmentuses, industrial process and water systems, material preservative uses and wood preservative uses resulting in discharge to waste treatment facilities with releases to surface water. The risk assessment will also include an assessment ofdirect and indirect effects to listed 

### (i.e., endangered and threatened) species. Ifthe assessment concludes that this use "may affect" a

Page 2 of 17

### 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



### INTRODUCTION
Didecyl dimethyl ammonium carbonate (DDA Carbonate) and didecyl dimethyl ammoniumbicarbonate (DDA Bicarbonate) are quaternary ammonium compounds. The didecyl dimethyl ammonium carbonates (DDA carbonates-includes both carbonate and bicarbonate)

were first registered with EPA onMay 15, 1995 for use as ahard non-porous surface disinfectant and a material preservative. Currently elevenproducts (1 

### technical and 10 end-use) are registered for the uses in the formulation ofwood preservatives, sapstain control, hard-surface disinfectants/sanitizers, food contact surface sanitizers, oilfield biocides and as a material preservative (metal working fluids, paints, household and industrial, cleaning and related products packaged in aerosol cans). A detailed list ofuse patterns and use sites ofthe DDA carbonates are listed below. Theproducts have declared DDA carbonates content of7.5% to 50%.

Antimicrobial Use Sites



### FoodHandling/storage establishmentspremisesandequipment 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 Waterproofgloves, shoe baths



### Industrialprocesses andwater systems Gas/oil recovery systems Hydrotesting pipelines orvessels Pipeline pigging and scraping operations



### Materials Preservatives Aerosol cans, petroleum products, cleaning products, and cleaning, sanitizing, and

disinfecting wipes for use onhard non-porous, surfaces Paints and decorative coatings Metalworking fluids Paper and Paperboard Metalworking Cutting Fluids



### Medicalpremisesandequipment Hard non-porous surfaces in hospitals, nursing homes and dentist offices, 

### etc. Salon I 

### barber tools and instruments

Page 3 of 17

### Ultrasound transducers, probes, mammography compressorplates



### Residentialandpublic accesspremises Air freshener Hard non-porous surfaces in household/domestic dwellings Laundry Holding tanks, gray water tanks.



### WoodPreservatives Pressure treatment
Exceptfor statements ofthe DDA carbonates content as total DDA content, all product chemistry data requirements have been satisfied.

A Reregistration Eligibility Decision (RED) has notbeen issued by the Agency for DDA Carbonate and DDA Bicarbonatebecause the initial registration date was after the November 1984, federal mandated cutofffor initiation ofthe RED process. An 

### ecological risk assessment1



### was conducted in 2007 for registration ofDDAcarbonates treated wood in aquatic environments. Risks to terrestrial wildlife were not calculated because information on leaching to soil and lack ofreliable exposure estimates. Risks to terrestrial plants were not calculated due to lack ofplant effects data for DDA carbonates and DDAC. Chronic aquatic risks could notbe calculated either, due to the lack ofchronic fish and invertebrate data. The acute level ofconcern was exceeded for endangered aquatic invertebrates but there was no exceedance for fish.



### Mode ofAction

Like other quarternary ammonium compounds DDA is a membrane-active agent, causing leakage ofintracellular molecules leading to death.



### A. Product Chemistry Summary ofBardac® 22C50- Mixture ofDDA Carbonate and DDA Bicarbonate

Chemical identity and the physical and chemical properties ofDDA carbonates are provided in Tables 1 and 2. The primary source ofinformation for this assessment was MRID numbers 43685701, 45524302, and 45524303. Except for a declaration ofthe total DDA content, all product chemistry data requirements have been satisfied for the DDA Carbonate and DDA Bicarbonate mixture.

1RASSB Norm Cook memorandum to Velma Noble, June 20, 2007, Carboquat (Bardac 22C50) Environmental Monitoring Study- DockWood TreatmentReview and Revised Ecological Risk Assessment. D332891, 332720, 332892, 332909, 332905. PC code: 069208. 

### Page 4 of 17Table 

### 1. Chemical Identity
Mixture ofDDACarbonate/DDABicarbonate- SO% Mixture of: Chemical Name N-decyl-N,N-dimethyl-1-decanaminium carbonate and N-decyl-N,N-dimethyl-1-decanaminium bicarbonate Mixture of: Common Name Didecyl dimethyl ammonium carbonate and Didecyl dimethyl ammonium bicarbonate Synonyms N

-,N-Dialkyl-N,N-dimethylammonium bicarbonate/carbonate
Trade Names Bardac® 22C50
Classification Quaternary Ammonium Compound (QAC) PC Code 069208 Mixture: CAS Nos. DDA Carbonate -148788-55-0 and DDA Bicarbonate- 148812-65-1 Mixture: MolecularFormula DDA Carbonate

-**[C2 ~sNh** C03 DDA Bicarbonate-**[C ~N]** **1** HC03 Mixture: MolecularWeight DDA Carbonate

- C4sH96N203 -713

.2597 g/mol DDA Bicarbonate-**C23~9N03** - 387.6424 g/mol 

# {**~tl** 

# l

t HCOf

### ~~"\ 

# I

Molecular Structure: 

# {**~,< /**  

# }

# : CO:J.Z

T bl 2 P d 

### t Ch • t D 

### t S

a e 

# . ro uc em1s ry a a ummaryo fDDAC b t /DDAB. b t**(SO~)** ar ona e 1car ona e 0 Guideline Physical and Chemical MixtureofDDA Carbonate/DDABicarbonate (SO%) Number Properties 830.1550 Product identity and composition Refer to Table 1. 830.1800 Enforcement analytical method HPLC 830.6302 Color Clear yellow liquid

. Colorless to pale yellow liquid. 830

.6303 Physical State Liquid concentrate 830

.6304 Odor Faint alcoholic amine odor Stability to sunlight, normal and Stable to elevated temperature, metals and sunlight. 830

.6313 elevated temperature, 1yr storage stability: Stable metals/metal ions 830.7000 pH 10.46 to 10

.80 at 10% active in aqueous solution at 25°C. 830.7050 UVNisibleAbsorption Not expected to absorb at A. >300 nm 830

.7100 Viscosity 63- 129 eSt at 25°C 830.7200 Melting point Not reg_uired.
Page 5 of 17Guideline Physical and Chemical Mixture ofDDA Carbonate/DDA Bicarbonate (50%) Number Properties 830.7220 Boiling point Not required. Similarto water 830.7300 Density 0.962 at 25°C Not applicable because the chemical structure has no 830.7370 Dissociation Constant dissociable groups otherthan the ion pairs shown in the molecular structure provided in Table 1.
830.7550 Partition coefficient (n- Not required-Ionic compound. octanoVwater) 830

.7840 Solubility in water 100% Soluble
830.7860 Solubility in organic solvents Bardac® 22C50 is freely soluble in water, lower alcohols, octanol, ketones and gly_cols. 830

.7950 Vaporpressure Not required-Ionic compound.



### B. Environmental Fate Summary

The environmental fate ofdidecyl dimethyl ammonium carbonates (DDA carbonatesincludes both carbonate andbicarbonate) is essentially the same as didecyl dimethyl ammonium chloride (DDAC, PC Code 069149), and therefore the data for DDAC were used to bridge to and help satisfy DDA carbonates environmental fate data requirements. DDA carbonates will disassociate upon contact with water to form the DDA cation and the carbonate/bicarbonate anions. Like DDAC, DDABicarbonate releases one mole ofDDA cations, however, DDA Carbonate releases two moles ofDDA cations. The DDA cation will sorb nearly irreversibly to soil and sedimentbecause ofthe negative charge associated with soil and sediment. Based on DDAC studies, the DDA cation is expected to be stable to hydrolysis and photodegradation in water and essentially stable to aquatic metabolism. However, DDA was found to be biodegradable in the Ready Biodegradability study. Except for an oysterbioconcentration study for DDA, all fate data needed to conduct an ecological risk assessment for DDA carbonate uses resulting in discharge to waste watertreatment plants are fulfilled.



### Abiotic Fate

Nonionized/IonizedRatio andpH

Theproduct chemistry data indicate that DDA Carbonate and Bicarbonate will disassociate immediately upon contact with water. DDA Bicarbonatereleases one mole ofDDA cations per mole; however, DDA Carbonate releases two moles ofDDA cations permole. The carbonate/bicarbonate ion equilibrium will depend onthe pH ofthe solution. Formation of bicarbonate ion (HC03 1-) from carbonic acid (HzC03) in water occurs with a pKa (disassociation constant) of6.4, while carbonate (C032") formation from bicarbonate occurs with a pKa ofat 

### 10.3 at 25 °C2

. As a result, the equilibrium between bicarbonate and carbonate will favor the presence ofbicarbonate in the range ofmost environmental pH values of5-7.

2 http://en.wikipedia.org/wiki/Carbonic_acid Page 6 of 17

### Hydrolysis andPhotolysis

DDAhas been shown using DDAC to behydrolytically stable under abiotic and buffered conditions over the pH 5-9 range (MRID 41175801). DDA is stable to photodegradation in pH 7 buffered aqueous solutions; even in the presence ofa photosensitizer (acetone), degradation is minimal (MRID 41175802). DDA is not subject to photodegradation in soil (MRID 42480701).


### Adsorption/Desorption

DDA is immobile in soil. A soil mobility study using DDAC reviewed bythe Agency shows that DDA has a strong tendency to bind to sediment/soil with Freundlich Kads 

### values of 1,095, 8,179, 32,791, and 30,851 in sand, sandy loam, silty clay loam, and silt loam soils, respectively. Because ofits strong adsorption to soils, DDA in aquatic systems is expected to partition to suspended particulates and sediment and is not expected to contaminate ground waters (MRID 41385301).



### Wood leaching

Information on the aqueous availability ofDDA from DDAC treated wood indicates that the use ofDDAC as a wood preservative mayresult in minimal DDA releases to the environment (MRID 45524305).



### BioticFate

DDA is expected to degrade with half-lives of9-13 days in hybrid sewage studies without clay and 45 days with added clay. The registrant submitted an OECD carbon and nitrogen transformation test, which demonstrated a lack ofeffects on glucose metabolism and an increase in ammonia formation with complex and clay rate, but no increase in nitrate formation. Because ofits electric charge and cell membrane activity, the DDAcation is not expected to bioconcentrate in fish.


### AquaticAerobicandAnaerobicMetabolism
Aquatic metabolism studies under aerobic and anaerobic conditions indicate that DDAC is stable to microbial degradation under STANDARD SUBDIVISION N tests. The calculated aerobic and anaerobic half-lives ofCarbon 14-labeledDDAC

# e 4

### C-DDA chloride) in flooded river water are 180 days and 261 days, respectively (MRIDs 42253802 and 42253803). Similarly, DDAC was found to be stable withvery little degradation in aerobic soils during a year-long metabolism study (MRID 42253801). However, in tests that were hybrids ofdifferent guidelines (MRIDs 4755512,-15, -17), DDAC that is not complexed with clay is considered to bereadily biodegradable. Onthe otherhand, tests using DDAC:Clay complexes demonstrated that sorption to clay prevented ready biodegradation. As a result, any DDAC that reaches bottom sediment would be likely to be more persistent than the DDAC in the water column.

In an acceptable aerobic aquatic biodegradation in a shake flask study (OCSPP 835.3100, MRID 47522212), the half-lives in a loam soil (5.6% organic matter) ranged from 10-

Page 7 of 1712 days, with an upper lOth confidence bound (CB) ofthe mean of 13 days. This study is intended to simulate ready biodegradability in the aquatic environment. 

### In this study, DDAC

was shown to bereadily biodegradable with -80 % oftheoretical C02(ThC02 ) formed in 28 days.



### In an acceptable ready biodegradability study using the headspace method (OECD 301B/40 CFR 796.3260, Modified SturmTest), the persistence ofDDAC in an un-inoculated river water/sediment system was studied (MRID 47522217). Thehalf-lives were 11 and 45 days in a non-clay and clay (one part DDAC and 10 parts clay) system, respectively. Underthe conditions ofthis study, DDAC-treated systems without clay achieved therequired threshold value of70% ThC02 evolution between 10 % degradation and 28 days ofstudy (17-20 days observed). However, DDAC:clay complex-treated systems did not achieve the required threshold value of70% ThC02 bywithin 28 days or the study length (55 days)

. These results

are expected given the strong tendency ofDDAC to sorb to clay and organic material. Ninety (90) and 52% ofthe theoretical C02(ThC02) evolved from the system

.


### In a hybrid aerobic aquatic metabolism/Ready Biodegradability test (OCSPP 835.3100/0ECD 301B), the registrant used clay, centrifuging, and acclimation ofinoculum (MRID 47522215). The first part ofthe study involved centrifuging ofclay in systems that were either acclimated ornot acclimated. The observed half-lives were about 12 days for each test, indicating that centrifuging the clay was the main factor. Twenty-seven percent ofThC02from acclimated and non-acclimated samples evolved from the system. The second test involved nonacclimated samples with no centrifugation. Thehalf-life was about 9 days. The DDAC:clay complex-treated systems did not achieve the required threshold value of70% ThC02evolution. However, the reference control (sodiumbenzoate) systems achieved the threshold valueby7 days posttreatment (%ThC02 evolved was 68-79 %), indicating the inoculum was viable and the test was valid.



### Biodegradability inActivatedSludge andActivatedSludge Inhibition

One guideline study for biodegradation in activated sludge was submitted (MRID 4755514). In this OECD 301A (dissolved organic carbon die-away) study, the half-lives of DDAC in acclimated sewage sludge were 6 and 8 days, with an upper lOth CB on mean of 11 days. The sludge concentrations were 5 and 10 mg carbon!L. Bardac 22 was considered to be readily biodegradable since 79 and 73 % (>70 %) removal ofdissolved organic carbon (DOC)

was observed in the 10-day window for the 5 and 10 mg Carbon/1 (MRID 47522214).



### In a Ready Biodegradabilitytest (OECD 301A, dissolved organic carbon die-away), the half-lives ofDDA chloride in acclimated sewage sludge were 6 and 8 days, with an upper lOth CB on mean of 11 days (MRID 47522214). The sludge concentrations were 5 and 10 mg carbon/L. Bardac 22 was considered to be readily biodegradable since 79 and 73% (>70 %) removal ofDOC was observed in the 10-day window for the 5 and 10 mg C/1.

Theregistrant submitted an OECD carbon and nitrogen transformation test, which represents heterotrophic bacteria in sediments. There were no effects on glucose metabolism at

Page 8 of 17

### 1, 3, and 10% complex ofDDAC:clay. However, there was some increase in ammonia formation with complex and clayrate, but no increase in nitrate formation (MRID 47522213). These results that the DDAC:clay complex did not affect the viability ofaerobic and facultative bacteria in the sediment. These bacteria are important for the function ofmetabolizing carbon in sediments. The nitrogen results indicate that nitrifying bacteria were not active inthe tested sediment, so no conclusions related to the DDAC:clay complex could be made.



### Bioconcentration

DDA is not expected to pose a concern for bioconcentration in non-filter feeding aquatic organisms. In 

### a fish bioconcentration study (MRID 45834101) mean steady state bioconcentration factors for DDA were determined to be 38, 140, and 81 in the edible, nonedible, and whole body fish tissue, respectively. Given that DDA is expected to have a high affinity to sorbing to organic and inorganic particulate matter there is a potential for filterfeeding organisms to uptake DDA sorbed to their food. A bioconcentration study using a filter feeding organism such as a mollusk is needed to address risk from this exposurepathway.


### Drinking Water

Based on the fate characteristics ofDDA, it is not expected to contaminate drinking water surface or groundwater sources. DDA reaching surface waters are expected to be associated with particulate matter and sediment. Additionally any particulate matter would beremoved during water treatment.



### Water Quality

DDA and DDA carbonates are not identified as a cause ofimpairment for any water bodies listed as impaired under section 303(d) ofthe Clean WaterAct, based on information provided at the Agency's National Pesticides Cause ofImpairment ofWaters website (searched July 11, 2012)3

. In 

### addition, no Total Maximum DailyLoads (TMDL) have been developed for DDA Carbonate/DDA Bicarbonate, based on information provided at the Agency's National Pesticide TMDL web site (searched July 11, 2012)4• 

### More information on impaired waterbodies and TMDLs canbefound at http://www.epa.gov/owow/tmdl/

. The Agency invites submission ofwater quality data for this pesticide. To the extent possible, data should conform to the quality standards in Appendix A ofthe OPP Standard Operating Procedure: Inclusion of Impaired WaterBody and Other Water QualityData in OPP's RegistrationReviewRiskAssessmentand Management Process (see: http://www.epa.gov/oppfeadllcb/ppdc/2006/november06/session1- sop.pdf), in order to ensure they canbeused quantitatively or qualitatively in pesticide risk assessments.



### Table 3. EnvironmentalFateResults and Status ofData Requirements

3

. http://iaspub.epa.gov/tmdl waters!O/attains nation cy.cause detail 303d?p cause group id=885 4 http://iaspub.epa

.gov/tmdl waters 10/attains nation

.tmdl pollutant detail?p pollutant group id=885&p pollutant group name=PESTICIDES 

### Page 9 of 17Test Guideline Guideline Result Comments/ Status ofData No. References Requirement Hydrolysis 161-1 Stable at pH 5, 7, and 9 MRID 41175801 Satisfied Photodegradation Stable in non-sensitized 161-2 and sensitized buffer MRID 41175802 Satisfied in water solutions Photodegradation 161-3 Stable MRID 42480701 Satisfied on soil Aerobic soil 162-1 Stable MRID 42253801 Satisfied Anaerobic aquatic 162-3 261 days MRID 42253802 Satisfied metabolism 835.4300 Aerobic aquatic 162-4 metabolism (soil OCSPP 835.4400 180 days MRID 42253803 Satisfied and water only) 10-12 days (upper 10m CB

on mean of 13 days) Aerobic aquatic 40 CFR 796

.3100 metabolism in This is assumed Readily biodegradable MRID 47522212 Satisfied surface water and to be 835.3100 ThC02evolution did not sediment reach 70 % by 10 days

.. but did reach 80 % by 28 days (end ofstudy)
River water Half-lives of 11 and 45 system days in non-clay and clay (uninoculated) systems, respectively.
No clay >70%ThC02 evolution MRID 47522217 OECD301B within 14-17 days for 40 CFR 796

.3260 DDAC only (readily Modified Sturm Satisfied biodegradable) Test Clay <70 % ThC02 evolution from DDAC:clay system (not readily biodegradable)
Ready Half-lives of6 and 8 days (upper lOth CB on mean Biodegradability of 11 days) test using activated sludge OECD301A 79 and 73 % removal of MRID 47522214 Satisfied Dissolved organic DOC in 10 days for carbon die-away DDAC only system with test 5 and 10 mg C/L (Readily biodegradable)

Page 

### 10 of 

### 17Guideline Comments/ Status ofData Test Guideline Result References**R~uirement** No. Centrifuged samples Half-lives ofabout 12 days for both nonacclimated and acclimated Aerobic aquatic OCSPP 835.3100 Non-centrifuged MRID 47522215 Satisfied metabolism (clay, centrifuging, and OECD301B Half-life ofabout 9 days inoculation) 70 %ThC02 "pass" level for ready biodegradability

was not reached

No effect ofDDAC and clay complex on heterotrophic bacteria in sediments

No effect on glucose metabolism at 1, 3, and 10 %complex of This is not a data OECD carbon and OECD 217 and DDAC:clay. MRID 47522213 requirement for nitrogen 216 this assessment. transformation test General increase in ammonia formation with complex and clay rate Nitrogen transformation portion oftest is not applicablebecause soil had no nitrifying bacteria

Freundlich Kads values of Satisfied 1,095, 8,179, 32,791, and Aged leaching Leaching- 30,851 in sand, sandy MRID 41385301 not required adsorption- 163-1 loam, silty clay loam, and because of desorption silt loam soils, DDAC stability**re~ective_!y.** in unaltered soils Bioconcentration factors Bioconcentration 165-4 of38X, 140X, and 81X in MRID 45834101 Satisfied in fish OCSPP 850.1730 the edible, non-edible, and whole body fish tissues. Leaching from Minimal leaching from MRID 45524305 Satisfied treated wood Ell-97 treated wood



### Page 11 of 17

### C. Ecological Effects Summary

Available ecotoxicity guideline studies and the results are summarized in Tables 4 and 5 for terrestrial and aquatic animals, respectively. Except for an activated sludge inhibition study,

an acute dermal contact honeybee study, and the oysterbioconcentration study discussed in the fate section, no additional effects data are anticipated to perform the ecological risk assessment.


### Toxicity to Terrestrial Organisms

A summary ofthe available toxicity data endpoints from registrant-submitted studies is provided in Table 4, data from DDAC was also used. The ecotoxicity endpoint values in the table are currently expressed as the active ingredients (a.i.s) either DDAC or as the DDA carbonates. To adjust for differences in molecular weight and the presence oftwo moles of DDA for every one mole ofDDA Carbonate as compared to DDAC and DDA Bicarbonate, all the values in the table will be expressed as DDA for the risk assessment. DDA is practically nontoxic to birds on a dietary basis butis moderately on an acute oral basis. Insect pollinator data are required based onDDA carbonate wood preservative uses. Mammalian toxicity data for evaluating exposure ofmammalian wildlife is available for acute oral toxicity and is discussed in the humanhealth scoping document.



### Table4: EcologicalEffects Data Summary ofDDA Carbonate/DDABicarbonate and DDACfor Terrestrial Organisms

OPPTS Study/Species Study Results Guideline Chemical (expressed as a.i.) 1 Comments No. MRID Number/ACC#
850.2100 Acute Oral LDso LDso = 95 mg ailkg Acceptable Bobwhite Quail NOAEL <31.2 mg ailkg Bardac 22C50 Moderately toxic 43685702 850.2100 Acute Oral LDso LD50 = 217 mg ailkg Acceptable Bobwhite Quail NOAEL = <31 mg ailkg DDAC Moderately toxic 41785803 850.2100 Acute Oral LDso LD50 = 54.4 mg ailkg Acceptable Bobwhite Quail NOAEL=<39 DDAC Moderately toxic 258798 850.2200 Eight-Day Dietary LCso LCso = >5620 ppm ai Acceptable/ Bobwhite Quail NOAEC = 1780 ppm ai Bardac 22C50 Practically non-toxic 43707101 850.2200 Eight-Day Dietary LCso LC50 = >5620 ppm ai Acceptable Mallard Duck NOAEC = 1000 ppm ai Bardac 22C50 Practically non-toxic 43649106

Page 

### 12 of 

### 17OPPTS Study/Species Study Results Guideline Chemical (expressed as a.i.i Comments No. MRID Number/ACC#
850.2200 Eight-Day Dietary LC50 = >5620 ppm ai Acceptable LCso NOAEC = 562 ppm ai Mallard Duck Practically non-toxic DDAC 41785802 850.2200 Eight-Day Dietary LCso LCso = >5620 ppm ai Acceptable Bobwhite Quail NOAEC = 1780 ppm ai DDAC Practically non-toxic 41785801 850.2200 Eight-Day Dietary LC50 LCso = >5620 ppm ai Acceptable Bobwhite Quail NOAEC = 3180 ppm DDAC Practically non-toxic 258798 850.2200 Eight-Day Dietary LCso LCso = >5620 ppm ai Acceptable Mallard Duck NOAEC = 1780 DDAC Practically non-toxic 258798
1· 

### .. Toxicity values currently expressed as active mgredient DDAC and DDA carbonates will be converted to DDAfor use in the risk assessment.



### Toxicity to Aquatic Organisms

A summary ofacute and chronic aquatic ecotoxicity data endpoints from registrantsubmitted studies for DDA carbonates and for DDAC is provided in Table 5. To adjust for differences in molecular weight and the presence oftwo moles ofDDAfor every one mole of DDA Carbonate as compared to DDAC and DDA Bicarbonate, all the values in the table will be expressed as DDA for the risk assessment. DDACand DDA carbonates appear moderately acutely toxic to highly toxic to fish butveryhighly toxic to aquatic invertebrates



### Table 5: Ecological Effects DataSummary ofDDA Carbonate/DDA Bicarbonate and DDAC for Aquatic Organisms
OPPTS Study/Species Study results Guideline Chemical (expressed as a.i.) 1 Comments No. MRIDNumber/ACC# 850.1075 Acute Toxicity to Rainbow 96-hourLC50

## =803 Acceptable Trout ppb ai Bardac 22C50 NOAEC = 580 ppm 43649108 Highly toxic 850.1075 AcuteToxicity to Bluegill 96-hourLC50

## =270 ppb ai Acceptable Sunfish NOAEC = 98 ppb ai Bardac 22C50 Highly toxic 43649107

Page 13 of 17OPPTS Study/Species Study results Guideline Chemical (expressed as a.i.i Comments No. MRID Number/ACC# 850.1075 Acute Toxicity to Bluegill 96-hourLC50 = 600 ppb ai Acceptable Sunfish Highly toxic DDAC 256571 850.1075 AcuteToxicity to Rainbow 96-hourLC50 = 2800 ppb ai Acceptable Trout Moderately toxic DDAC 256571 850

. 1075 Acute Toxicity to Bluegill 96-hourLC50 = 270 ppb ai Acceptable Sunfish Highly toxic DDAC 007958 850.1075 Acute Toxicity to Rainbow 96-hourLC50 = 1100 ppb ai Acceptable Trout Moderately toxic DDAC 007958 850.1075 Acute Toxicity to Bluegill 96-hourLC50 = 320 ppb ai Acceptable Sunfish NOAEC=<100 DDAC Highly toxic 41578001 850.1075 Acute Toxicity to Rainbow 96-hourLC50 = 1000 ppb ai Acceptable Trout NOAEC = 590ppb ai DDAC Moderately toxic 41578003 850

. 1400 FreshwaterFish chronic toxicity: Length, dry wt, wet wt: Acceptable Fathead minnow in fish early- NOAEC = 18 ug/L (supplemental) life stage LOAEC = 32 ug/L Bardac 22C50 Survival: 46362301 NOAEC = 86 ug/L LOAEC = 170 ug/L Hatching success: NOAEC = >170 ug/L LOAEC = > 170 ug/L 850.1010 AcuteToxicity to WaterFlea EC50 = 66 ug/L Acceptable (Daphnia magna) NOAEL = 33 ug/L Bardac 22C50 Very highly toxic 43649109 850.1010 AcuteToxicity to WaterFlea ECso = 18 ug/L Acceptable (Daphnia magna) NOAEC = < 5.6 ug/L DDAC Very highly toxic 225596 850

. 1010 AcuteToxicity to WaterFlea EC50 = 94 ug/L Acceptable (Daphnia magna) NOAEC = 74 ug/L DDAC Very highly toxic 41578002



### Page 14 of 17OPPTS Study/Species Study results Guideline Chemical (expressed as a.i.i Comments No. MRID Number/ACC# 850.1300 Chronic Freshwater 21 day Length and dry wts: Acceptable invertebrate study (Daphnia NOAEC

## =27 ug ai/L magna) LOAEC

## = 46 ug ai/L Bardac 22C50 AdultMortality: 46295805 NOAEC

## = 46 ug ai/L LOAEC

## =77 ug ai/L Reproductive success: NOAEC

## =>77 ug ai/L LOAEC

## =77 ug ai/L 850.1075 Acute Toxicity Test using LCso

## =1100 ug/L Acceptable Sheepshead minnow NOAEC

## =890 ug/L (Cyprinodon variegates) Moderately toxic Bardac 22C50 43649110 850.1075 Acute Toxicity Test using LCso

## =960 ug/L Acceptable Sheepshead minnow NOAEC

## =390 ug/L (Cyprinodon variegates) Highly toxic DDAC 43620001 850.1025 AcuteToxicity test using ECso

## =82 ug/L Supplemental Estuarine/Marine invertebrates: NOAEC

## =25 ug/L Eastern oyster (Crassostrea Very highly toxic virginica) Bardac 22C50 43649112 850.1025 AcuteToxicity Test using EC50

## =94 ug/L Acceptable Estuarine/Marine invertebrates: NOAEC

## =63 ug/L Eastern Oyster (Crassostrea Very highly toxic virginica) DDAC 43260003 850.1025 AcuteToxicity Test using ECso

## =6400 ug/L Acceptable Estuarine/Marine invertebrates: NOAEC

## =90 ug/L Eastern Oyster (Crassostrea Moderately toxic virginica) DDAC 249002 850.1735 AcuteToxicity oftreated 14 day emergence: Supplemental sediment to FreshwaterMidge ECso

## =1438 mg/Kg (Chironomus tentans) Growth emergence: DDAC NOAEC

## =530 mg/Kg 45821701 28 day emergence: ECso

## =1981 mg/Kg NOAEC

## =260 mg/Kg



### Page 15 of 17OPPTS Study/Species Studyresults Guideline Chemical (expressed as a.i.) 1 Comments No. MRID Number/ACC# 850.1735 AcuteToxicity oftreated 10 day survival: Acceptable sediment to Freshwater Midge EC50= 1254 mg/Kg (Chironomus tentans) 10 day growth: Bardac 22C50 EC50 = 1063 mg/Kg 46375402 Growth and survival: NOAEC = 250 mg/Kg LOAEC = 500 mg/I(g 850.1740 AcuteToxicity oftreated 10 day % survival: Supplemental sediment to Estuarine Amphipod EC5o = 24.1 mg ai/Kg (Leptocheirusplumulosus) NOAEC = 13 mg ai/Kg Bardac 22C50 LOAEC = 25 mg ai/Kg 46375403 850.4225 Seedling emergence and ECz5 =55.4 mg ai/Kg (dry wt) Supplemental 850.4250 vegetative vigor using Rice NOAEC = 39.1 mg ai/Kg (Oryza sativa) CarboquatWP 46375401 850.5400 Toxicity to Green algae EC50 = 26 ug ai/L Acceptable (Selenastrum capricornutum) NOAEC = 14 ug ai/L Bardac 22C50 45896402 850

.5400 Toxicity to Blue-green EC50 =58 ug ai/L Acceptable cyanobacteria (Anabaena NOAEC = 40 ug ai/L flosaquae) Bardac 22C50 46295801 850.5400 Toxicity to FreshwaterDiatom EC50 = 11.3 ug ai!L Acceptable (Naviculapelliculosa) NOAEC = 5.4 ug ai/L Bardac 22C50 46295803 850

.5400 Toxicity to marine Diatom EC5 o = 25 ug ai/L Acceptable (Skeletonema costatum) NOAEC = 20ug ai/L Bardac 22C50 46295804 850.4400 Toxicity to Floating macrophyte ECso = 118.8 ug ai/L Acceptable (Lemna gibba) NOAEC = 9.1 mg Bardac 22C50 46295802



## EnvironmentalFateandEcotoxicity Data Gaps and Anticipated Work

The Agency plans on performing an ecological risk assessment for those premise and equipment uses, industrial process and water systems, material preservative uses and wood preservative uses resulting in discharge (such as down the drain disposal ofused cleaning and disinfecting solutions, laundry water, etc.) 

### to waste treatment facilities with subsequent releases
Page 16 of 17

### to surface water. The ecological risk assessment planned during registrationreview will allow the Agency to make a "no effect" or "may affect" determination for federally listed threatened or endangered species (listed species) and their designed 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.



### Environmental Fate Data Gaps
Except for the oysterbioconcentration study which is also an ecological effects study, there are no environmental fate data gaps. 

### Ecotoxicity Data Gaps

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

• Oyster bioconcentration study (OCSPP 850.1730);

• Honey bee acute contact study (OCSPP 850.3020);

• Toxicity ofresidues to honeybees (OCSPP 850.3030); and

• Activated Sludge Respiration Inhibition (OCSPP 850.3300 or OECD 209).



### Other Data Gaps

For estimating environmental exposure concentrations in the aquatic environment, the Agency anticipates needing production volume data for the uses as input in down-the-drain models, and industrial and material preservative emission scenario models.

Page 17 of 17