Page 2 of 103 TABLE OF CONTENTS

EXECUTIVE SUMMARY .......................................................................................................... 8

1.0 INTRODUCTION ........................................................................................................... 12

2.0 ENVIRONMENTAL FATE ASSESSMENT ................................................................ 14

2.1 Product Chemistry and Chemical Structure ................................................................... 14

2.2 Summary of Abiotic Environm ental Fate Processes ...................................................... 15

2.3 Summary of Biotic Environmental Fate Processes ........................................................ 15

2.4 Summary of Environmental Transport Processes .......................................................... 15

2.5 Summary of Environmental Fate in Wastewater Treatment .......................................... 16

2.0 HUMAN HEALTH RISK ASSESSMENT .................................................................... 17

3.1 Hazard Assessment ....................................................................................................... 17
3.2.1 FQPA Considerations ................................................................................................. 19

3.3 Dietary Assessment ........................................................................................................ 20

3.2.2 Dietary Exposure and Risk Analysis ...................................................................... 20

3.3 Residential Non-Dietary Assessment ............................................................................. 25

3.4 Aggregate and Cumulative Exposure ............................................................................. 26

3.4.1 Aggregate Exposures .............................................................................................. 26

3.4.2 Cumulative Exposures ............................................................................................ 26

3.5 Occupational Exposure .................................................................................................. 26

3.7 Human Health Risk Characterization ............................................................................. 27

3.0 ECOLOGICAL RISK ASSESSMENT .......................................................................... 28

4.1 Selected Ecological Toxicity Endpoints ........................................................................ 28

4.1.1 Effects to Wastewater Treatme nt Plant Microorganisms ....................................... 29

4.2 Summary of Ecological Exposur e Assessment Approach ............................................. 30

4.2.1 EPA’s Estimation of Exposure of Freshwater Fish and Invertebrates to ATMD in
the Water Column .............................................................................................................. ... 31

4.2.2 EPA’s Estimation of Exposure of Freshwat er Benthic Invertebrates to ATMD in
Sediments ..................................................................................................................... ......... 32Page 3 of 103 4.2.3 EPA’s Estimation of Exposure of Estuarin e/Marine Fish and Invertebrates to
ATMD in the Water Column ................................................................................................ 33

4.2.4 EPA’s Estimation of Exposure of Estuar ine/Marine Benthic Invertebrates to
ATMD in Sediments ............................................................................................................. 34

4.2.5 EPA’s Estimation of Exposures to Piscivorous Birds and Mammals ..................... 34

4.2.6 Mexel’s Estimation of Exposure to ATMD Released from Cooling Towers and Once-Through Industrial Cooling Water Systems ................................................................ 34

4.3 Estimation of Risks to Aquatic Organisms .................................................................... 35

4.3.1 Estimation of Risks to Freshwater Orga nisms Exposed to ATMD in the Water
Column 35

4.3.2 Estimation of Risks to Freshwater Bent hic Invertebrates Exposed to ATMD in
Sediments ..................................................................................................................... ......... 42

4.3.3 Estimation of Risks to Estuarine/Marine Organisms Exposed to ATMD in the
Water Column .................................................................................................................. ..... 43

4.3.4 Estimation of Risks to Estuarine/Marine Benthic Invertebrates Exposed to ATMD
in Sediments .................................................................................................................. ........ 44

4.3.5 Estimation of Risks to Piscivorous Birds and Mammals ........................................ 45

4.4 Ecological Risk Characterization ................................................................................... 45
Evaluation of EPA’s Ecological Exposure a nd Risk Assessment Modeling Results ........... 45
Uncertainties Resulting from Gaps in Ecotoxicity Data ....................................................... 47
Uncertainties Resulting from Gaps in Environmental Fate Data .......................................... 47
Evaluation of Modeling Resu lts Provided by Mexel ............................................................ 48
Evaluation of WET Results Submitted by Mexel ................................................................. 50

4.7 Section 4 References ...................................................................................................... 51

5.0 SUMMARY OF POTENTIAL HUMAN AND ECOLOGICAL RISKS ................... 52

APPENDIX A: ENVIRONMENTAL FATE DATA ............................................................ 57

Introduction .................................................................................................................. ............. 57
Product Chemistry ............................................................................................................. ....... 59

Environmental Fate ............................................................................................................ ....... 60
Hydrolysis .................................................................................................................... ......... 60
Photodegradation in Water ................................................................................................... 6 0
Aerobic Aquatic Metabolism ................................................................................................ 61
Anaerobic Aquatic Metabolism ............................................................................................ 61Page 4 of 103 Leaching-Adsorption-Desorption ......................................................................................... 61

Bioconcentration in Fish ...................................................................................................... . 62
Sorption to Activated Sludge ................................................................................................ 6 2
Activated Sludge Respiration Inhibition (ASRI) .................................................................. 63
Biodegradability in Wastewater Treatment .......................................................................... 63

APPENDIX B: HUMAN HEALTH TOXICITY DATA ...................................................... 69

APPENDIX C: ECOTOXICITY DATA ................................................................................ 80
Toxicity to Terrestrial Organisms ............................................................................................. 80

Birds ......................................................................................................................... ............. 80
Nontarget Insects ............................................................................................................. ..... 82
Toxicity to Aquatic Organisms ................................................................................................. 82

Freshwater Fish ............................................................................................................... ...... 82
Whole Effluent Toxicity Testing .............................................................................................. 90
Calvert Cliffs Nuclear Power Plant (CCNPP) Whole Effluent Toxicity Testing ................. 90
Donald C. Cook Nuclear Power Plant (DCCNPP ) Whole Effluent Toxicity Testing .......... 92
Whole Effluent Toxicity Study References .............................................................................. 93

APPENDIX D: RISK ESTIMATION METHODS ............................................................... 95

APPENDIX E: ECOLOGICAL EXPOSURE MOD ELING METHODOLOGY ............. 97
Methodology for Estimating Water Column Exposu re to Aquatic Organisms from Release of ATMD from Recirculating Cooling Towers............................................................................ 97
Methodology for Estimating Exposure to Aquatic Organisms from Release of ATMD from Once-through cooling systems ................................................................................................ 1 01
Description of High-End Versus Average Case Scenario ...................................................... 102
Methodology for Estimating Sediment Exposure to Benthic Aquatic Organisms from Release of ATMD from Once-Through and R ecirculating Cooling Towers ....................................... 102

APPENDIX E – REFERENCES ............................................................................................ 103Page 5 of 103 LIST OF TABLES

Table 1: Endpoints for use in AT MD Drinking Water Assessments ........................................... 19 Table 2: Estimated Drinking Water Concentr ations (EDWCs) of ATMD for Surface Water using the E-FAST Model ........................................................................................................ ...... 22 Table 3: Summary of Acute and Chronic Diet ary Exposure and Risk Analyses for ATMD (Endof-pipe water concentration) .................................................................................................. ....... 22 Table 4: Summary of Acute and Chronic Dietar y Exposure and Risk Analyses for ATMD (Once through cooling system, 0% removal, 10th percentil e ratio of stream flow to plant flow) .......... 23 Table 5: Summary of Acute and Chronic Dietar y Exposure and Risk Analyses for ATMD (Once through cooling system, 0% removal, 50th percentil e ratio of stream flow to plant flow) .......... 24 Table 6: Summary of Acute and Chronic Di etary Exposure and Risk Analyses for ATMD (Recirculating cooling tower, 0% removal, 10th percentile ratio of stream flow to plant flow) .. 24 Table 7: Effects Endpoints Selected for Assessing Ecological Risks to ATMD ......................... 28
Table 8: Estimated Concentrations of ATMD in Freshwater Benthic Sediment Based on 10th
and 50th Percentile Surface Wa ter Concentrations Estimated from the General Population Exposures and Industrial Rel eases Module of E-FAST ............................................................... 33 Table 9: Estimates of Numbers of Day Per Y ear of Exceedance of Acute COCs for Freshwater Organisms Downstream of Mode rate-Size Recirculating Coo ling Towers (0.0029 kg/site/day
release of ATMD before treatment based on 2.5 ppm residual of product (42.5 ug/L active ingredient)) .................................................................................................................. .................. 36 Table 10: Estimates of Numbers of Day Per Year of Exceedance of Endangered/Listed COCs for Freshwater Organisms Downstream of Mode rate-Size Recirculating Cooling Towers (0.0029 kg/site/day release of ATMD before treatment based on 2.5 ppm residual of product (42.5 ug/L active ingredient)) ........................................................................................................... .............. 37 Table 11: Estimates of Numbers of Day Pe r Year of Exceedance of Chronic COCs for Freshwater Organisms Downstr eam of Moderate-Size Recirc ulating Cooling Towers (0.0029 kg/site/day release of ATMD before treatment based on 2.5 ppm residual of product (42.5 ug/L active ingredient)) ........................................................................................................... .............. 37 Table 12: Estimates of Numbers of Day Per Y ear of Exceedance of Acute COCs for Freshwater Organisms Downstream of Large- Size Recirculating Cooling Towers (0.0029 kg/site/day release of ATMD before treatment based on 2.5 ppm resi dual of product (42.5 ug/L active ingredient))

............................................................................................................................... ........................ 38 Table 13: Estimates of Numbers of Day Per Year of Exceedance of Endangered/Listed COCs for Freshwater Organisms Downstream of La rge-Size Recirculating Cooling Towers (0.0029 kg/site/day release of ATMD before treatment based on 2.5 ppm residual of product (42.5 ug/L active ingredient)) ........................................................................................................... .............. 38 Table 14: Estimates of Numbers of Day Pe r Year of Exceedance of Chronic COCs for Freshwater Organisms Downstream of Larg e-Size Recirculating Cooling Towers (0.0029Page 6 of 103 kg/site/day release of ATMD before treatment based on 2.5 ppm residual of product (42.5 ug/L active ingredient)) ........................................................................................................... .............. 39 Table 15: Estimates of Numbers of Days of Exceedance of COCs for Freshwater Organisms Downstream of Once-through cooling systems with an Intake Flow of 2 Million Gallons per Day (MGD) Assuming No Treatment and 2.5 ppm Resi dual of Product (42.5 ug/L active ingredient, ATMD) ......................................................................................................................... ................ 39 Table 16: Estimates of Numbers of Days of Exceedance of COCs for Freshwater Organisms Downstream of Once-through cooling systems with an Intake Flow of 20 Million Gallons per Day (MGD) Assuming No Treatment and 2.5 ppm Residual of Product (42.5 ug/L active ingredient, ATMD) ............................................................................................................. .......... 40 Table 17: Estimates of Numbers of Days of Exceedance of COCs for Freshwater Organisms Downstream of Once-through cooling systems with an Intake Flow of 50 Million Gallons per Day (MGD) Assuming No Treatment and 2.5 ppm Residual of Product (42.5 ug/L active ingredient, ATMD) ............................................................................................................. .......... 41 Table 18: Estimates of Numbers of Days of Exceedance of COCs for Freshwater Organisms Downstream of Once-through cooling systems with an Intake Flow of 100 Million Gallons per Day (MGD) Assuming No Treatment and 2.5 ppm Residual of Product (42.5 ug/L active ingredient, ATMD) ............................................................................................................. .......... 41 Table 19: Risk Quotients for Freshwater Bent hic Organisms Based on Estimated Concentrations of ATMD in Sediment (sediment concentrations for 10th and 50th percentile 7Q10 Distribution)

............................................................................................................................... ........................ 42
Table 20: Concentrations of Concern for Risk to Water Column-Dwelling Estuarine/Marine Organisms and Dilution Factors That Would Minimize Risks ..................................................... 44 Table 21. Chemical, Physical, and Environmental Fate Properties of Du omeen C from EPI-Suite
4.11 and Guideline Studies .................................................................................................... ....... 64 Table 22: Avian Acute-Oral Toxicity .......................................................................................... 81 Table 23: Avian Dietary Toxicity ............................................................................................. ... 81
Table 24: Freshwater Fish Acute Toxicity ................................................................................... 82
Table 25: Freshwater Fish Chronic Toxicity ............................................................................... 83
Table 26: Freshwater Invertebrate s Acute and Chronic Toxicity ................................................ 83
Table 27: Estuarine/Marine Inverteb rates Acute and Chronic Toxicity ...................................... 84 Table 28: Aquatic Plant Toxicity ............................................................................................. .... 85 Table 29: Subchronic Sediment Toxicity .................................................................................... 86 Table 30: Summary of Whole Effluent Toxicity Test Resu lts for CCNPP in 2011 during Mexel
Treatment Trial ............................................................................................................... .............. 91 Table 31: Summary of Whole Effluent Toxi city Test Results for DCCNPP in 2006 and 2007 during Mexel Treatment Trial .................................................................................................. ..... 93 Table 32 Risk Presumption Categories ........................................................................................ 95Page 7 of 103 

### LIST OF FIGURES

Figure 1: Chemical Structure of Dodecyl-1,3-propanediamine. .................................................. 14Page 8 of 103 

### EXECUTIVE SUMMARY

This document presents the United States Environmental Protection Agency’s human and ecological risk assessment for the new use of the active ingredient, N-coco 1,3-diaminopropane (also sometimes referred to as N-(coco alkyl)tri methylenendiamine, Duomeen C, and ATMD) in
MEXEL 432/0 to control biofou ling in once-through and recircul ating cooling towers. The active ingredient in MEXEL 432/0 is gene rally hereinafter re ferred to as ATMD (alkyltrimethylenediamine).

MEXEL 432/0 is to be used for the cont rol of biofouling, including zebra mussels and clams in once-through cooling and cooling tower circu its with closed de livery systems for nonpotable industrial freshwater a nd sea water systems. The produc t may be applied to maintain clean systems or to treat systems that are alread y fouled. Normal frequency of treatment is once per day or as needed to maintain control. The amount of the daily dose is determined by the circuit characteristics. The daily dose is 4.0 ppm for 30 minutes with a re sidual concentration of 2.5 ppm.

According to the product labe l, the concentration of ac tive ingredient, ATMD, is 1.7 percent. Based on maintenance of 2.5 ppm pr oduct residual, this corresponds to 42.5 ug/L
ATMD.

ATMD would not be expected to pose higher risks to aquatic organisms than alternative
chemical substances that could be used as bi ofoulants in recirculati ng cooling tower and oncethrough cooling systems. Since facilities that woul d be expected to use this product already have NPDES permits for biofoulants, there would be no increased risks to aquatic systems nor increased regulatory burden for permit writers from the use of ATMD.

The exposure scenarios that form the basis of EPA’s risk assessment include releases to surface water from large-and moderate size re circulating cooling towers and, once-through cooling systems. For recirculating cooling towers , exposures from releases of ATMD to surface
water were estimated with and without wastewat er treatment. For once-through cooling systems,
it was assumed that no treatment of effluent o ccurs prior to discharge to surface water.

This risk assessment considers risks to bot h humans and ecological organisms. Risks to
humans evaluated in this assessm ent include potential dietary ri sks from ingestion of drinking water and potential risks from occupational ex posure during mixing and loading of ATMD. Estimates of potential dietary risk s to humans from ingestion of drinking water were determined to be negligible based on worst case estimates of drinking water concen trations and published information on drinking water consumption by huma ns at a high level of consumption.

Although potential risks were identified for occupational dermal and inhalation exposure during mixing and loading, these risks can be minimized if the proposed product label isPage 9 of 103 modified to specify “closed load ing and delivery systems”. (The proposed label only specifies “closed delivery systems”.)

The ecological risk assessment and charac terization for ATMD considers three key components:

 EPA’s assessment of risks to ecological organisms from exposure to ATMD;

 Whole Effluent Toxicity (WET) test data submitted by the registrant from two once through cooling systems; and

 Site-Specific modeling submitted by the registrant.

EPA ecological modeling results are based on lo adings that would estimate surface water concentrations for peak exposures. According to use instructions on the proposed label, the daily dose of MEXEL 432/0 is 4.0 ppm for 30 minutes with a residual concentration of 2.5 ppm. (The residual concentration of ATMD at 1.7% in pr oduct would be 42.5 ug/L. ) The proposed label also states that normal frequency of treatment is once per day or as needed to maintain control. Since the proposed label contained no upper limit on the frequency of treatment on a daily basis, EPA assumed that a 2.5 ppm residual produc t (42.5 ug/L ATMD) would be maintained continuously over a 24-hour period. This assu mption serves two purposes: (1) It provides estimates of peak exposures that are needed to estimates acute risks to aquatic organisms and (2) it provides a worst case exposure estimate based on the lack of an upper limit of application frequency on the product label.

If the maximum application of MEXEL 432/0 is limited to a single dose applied daily for 30 minutes, peak daily hourly and chronic peak risk estimates used to assess exposures to aquatic organisms would be reduced. Ba sed on guidelines for Whole Efflue nt Toxicity tests, for acute criteria, EPA recommends an averaging period of 1 hour and for chronic criteria an averaging period of 4 days. Based on these guidelines, daily loadings that EPA used in its modeling for calculating acute exposures would decrease by a factor of 2 and fo r chronic exposures by a factor of 48. These adjustments would reduce EPA’s es timates of acute and chronic exposures and risks to aquatic organisms in the water column.

When interpreting the results of EPA’s hum an and ecological risk assessment, it is important to note that sorption of ATMD to suspended solids in the water column was not quantitatively considered since EPA’s E-FA ST model was unable to account for this phenomenon. By extrapolation from laboratory studies on adsorption/desorption of ATMD in soils, ATMD would be expected to have a very high potential to sorb to suspended sediments in the water column. Accounting for sorption of ATMD to susp ended sediments in the water
column would further reduce EPA’s estimates of acute and chronic exposures and risks to aquatic organisms in the water column.Page 10 of 103 Two general quantitative appr oaches were used by EPA to assess risks to ecological organisms: a risk quotient (RQ) method and a pr obabilistic method (These are discussed further in Appendix D).

The probabilistic approach was used to estima te potential risks to freshwater fish and invertebrates. Risk estimates are provided as number of days per year of exceedance of concentration of concern (COC) downstream of a facility. Exceedance of an acute COC and of an endangered/listed acute COC for one day per year or more indicates that there may be potential for acute adverse effects to freshwater organisms. Exceedance of chronic COCs for 20 days or more indicates that there may be pot ential chronic adverse effects to freshwater organisms. Both average case and high end scenarios were evaluated. For the high-end scenario, results of the number of days per ye ar that COCs are exceeded is based on the upper
10 th percentile of the rati o of stream flows to plant flows (A lso referred to as Stream Dilution Factors (SDFs) . For the average case scenario, re sults of the number of days per year that COCs
are exceeded are based on the 50 th percentile of SDFs. For the upper 10 th percentile SDFs, or high-end scenario, the stream flow to plant flow ratio is relatively low since plant flows can
contribute considerable volume to the flow of the stream and resulting surface water concentrations can be relatively high. For the 50 th %ile SDF, the stream flow to plant flow ratio is more typical. The risk quotient method was us ed to estimate potential risks to freshwater benthic invertebrates, marine/est uarine freshwater fish and inve rtebrates, and estuarine/marine benthic organisms.

For recirculating cooling to wers on freshwater streams:. Based on the average case scenario, there are few risks of concern for the moderate-size system even when no treatment of released water is considered. For large syst ems, concentrations of concern for algae are potentially exceeded for up to 17 days per year and exceedances are 1-6 days for other organisms. When treatment is considered, days when COC are exceeded are up to 7 days for algae and 0-2 days for other aquatic organisms. For estuarine systems, RQ’s (assuming end-ofpipe concentrations) are 0.3 for fish, 2.2 for invertebrates and 3.9 for algae.

For once-through cooling systems on freshwat er streams: Based on the average case scenario for small systems (2 million gallons per day), concentrations of concern for algae are potentially exceeded for up to 26 days per year, exceedances are 3-10 days for other organisms. For large systems (100 million gallons per day) , concentrations of concern for algae are potentially exceeded for up to 160 days per year, exceedances are 39-83 days for other organisms. Acute RQs for estuarine organisms range up to 4.8 and chronic RQs range up to 8.3. There is generally no treatment of water fo r once-through cooling systems; therefore, no
treatment was assumed for this assessment.

A qualitative approach was used to conclude that the potential risks to piscivorus birds and mammals from the use of ATMD in cooling systems are low.Page 11 of 103 Releases of ATMD from recirculating c ooling towers to receiving water bodies and associated exposures are predicted to be mu ch lower than those from once-through cooling systems. First, releases from recirculating cooling towers are from blowdown water, which constitutes a fraction of the total cooling tower intake flow, whereas releases from once-through cooling systems consist of the total intake flow . (Blowdown is assumed to be only 0.06 percent of recirculating cooling tower in take flow.) Second, e ffluents from recirculating cooling towers may possibly undergo wastewater treatment wh ereas effluents from once-through cooling systems would not.

In a non-guideline study submitted to the Ag ency (Ackerman, D, F Ghillebaert, and M.W. Glass, 2013: MRID 49040220), Mexel used two modeling approaches to estimate exposures and risks to aquatic organisms dow nstream of two power plants which Mexel considered to be atypical and to have the gr eatest impact. Results on days per year of exceedance for the two facilities modeled are ge neral (presented in graphs) with no results provided for specific COCs. Although the two facilities modeled by Mexel might provide conservative estimates of exposure relative to ot her facilities where AT MD could be used, EPA cannot conclude based on modeling results that th e use of ATMD at these types of facilities will not pose potential concerns for exposure a nd risk to aquatic organisms. .

Whole effluent toxicity testing from two facilities, Calvert Cliffs Nuclear Power Plant (CCNPP) and Donald C. Cook Nuclear Power Pl ant (DCCNPP) conducting efficacy trials with Mexel were submitted by the registrant (MRID 49208816); details of these studies are provided in Appendix E. Both facilities have once through cooling systems. The studies show that under certain dosing regimes and mixing z ones there are facilities that w ould be able to use Mexel in once through cooling systems wit hout resulting in unreasonable a dverse effects to the aquatic
environment. For facilities that need to meet limits at the end-of-pip e, however, the proposed
label rate would result in exceed ances for once-through systems.

Major uncertainties with the risk assessment ar e associated with gaps in ecotoxicity and environmental fate data. The Agency used mode ls and acute to chronic ratio calculations to account for missing data. Additionally, no ecotoxici ty data are available for the formulated product. Data for the TGAI, which comprise s 1.7% of the product, may underestimate the toxicity of the formulation. The Agency assume d stability of ATMD in the aquatic environment since no aquatic metabolism studies provided in formation on degradates. Further, when interpreting the results of EPA’ s human and ecological risk asse ssment, it is important to note that sorption of ATMD to suspended solids in the water column was not quantitatively considered; this would lead to overestimates of surface wa ter concentrations predicted
downstream of facilities where ATMD would be expected to be used.Page 12 of 103 

### 1.0 INTRODUCTION

This document presents the United States Environmental Protection Agency’s human and ecological risk assessment for the new use of the active ingredient, N-coco 1,3-diaminopropane (also sometimes referred to as N-(coco alkyl)tri methylenendiamine, Duomeen C, and ATMD) in
MEXEL 432/0 to control biofou ling in once-through and recircul ating cooling towers. The active ingredient in MEXEL 432/0 is gene rally hereinafter re ferred to as ATMD (alkyltrimethylenediamine).

MEXEL 432/0 is to be used for the cont rol of biofouling, including zebra mussels and clams in once-through cooling and cooling tower circu its with closed de livery systems for nonpotable industrial freshwater a nd sea water systems. The produc t may be applied to maintain clean systems or to treat systems that are alread y fouled. Normal frequency of treatment is once per day or as needed to maintain control. The amount of the daily dose is determined by the circuit characteristics. The daily dose is 4.0 ppm for 30 minutes with a re sidual concentration of 2.5 ppm.

The concentration of active ingredient, AT MD, in MEXEL 432/0 is 1.7 percent. Based on maintenance of 2.5 parts pe r million (ppm) product residual, this corresponds to 42.5 micrograms per liter (ug/L) ATMD.

The exposure scenarios that form the basis of EPA’s risk assessment include releases to
surface water from:

 large-size recirculating cooling towers;

 moderate-size recirculati ng cooling towers; and

 once-through coo ling systems.

For recirculating cooling towers , exposures from releases of ATMD to surface water were
estimated with and without wastewater treatme nt. The estimates of percent removal during
wastewater treatment are based on experimental results reported in the activated sludge sorption isotherm study submitted by the registrant and are based on sorption of the active ingredient by activated sludge after 4 and 6 hours under conditions that simula te an activated sludge basin (MRID 49040205; Schaefer, E and A Ponizovsky (2012). Four hours of treatment is considered
the low end of the duration of treatment in an activated sludge aeration basin and six hours of
treatment is considered to be the average period of treatment.

For once-through cooling systems, it was assu med that no treatment of effluent occurs prior to discharge to surface water.

This risk assessment considers risks to bot h humans and ecological organisms. Risks to
humans evaluated in this assessm ent include potential dietary ri sks from ingestion of drinkingPage 13 of 103 water and potential risks from occupational ex posure during mixing and loading of ATMD. Worst case estimates of drinking water concen trations were derived from end of pipe concentrations of ATMD and high-end estimate s of surface water concentrations from EPA’s Exposure and Fate Assessment Screening Tool (E-FAST) model. By extrapolation from laboratory studies on adsorption/desorption of AT MD in soils, ATMD would be expected to have a very high potential to so rb to suspended sediments in the water column. Since EPA’s models were unable to account for the phenom enon of sorption of ATMD to suspended
sediments in the water bodies downstream of facilities where ATMD can be used, estimated surface water concentrations do not quanti tatively consider this phenomenon.

The ecological risk assessment considers three key components:

 EPA’s assessment of risks to ecological organisms from exposure to ATMD;

 Site-Specific modeling submitte d by the registrant, and.

 Whole Effluent Toxicity (WET) test data submitted by the registrant; and

In EPA’s assessment of ri sks to ecological organisms from exposure to ATMD, two general quantitative approaches were used to assess risks: a risk quot ient (RQ) method and a probabilistic method (These are discussed further in Appendix D). The probabilistic approach was used to estimate potential risks to freshwater aquatic organisms. The risk quotient method was used to estimate potential risks to both freshwater and estuarine/marine benthic invertebrates, and to estuarine/marine orga nisms in the water column. In addition, for marine/estuarine fish and invertebrates, dilution factors that would be needed to mitigate
exceedance of concentrations of concern were estimated. In estimating sediment concentrations of ATMD to which freshwater benthic organi sms would be exposed, estimated surface water concentrations were multiplied by average experimentally-determined leaching adsorption/desorption values. In estimating sedime nt concentrations to which estuarine/marine organisms would be exposed, the effluent concentr ation of ATMD at the end of pipe determined from information on the product label was mu ltiplied by average experimentally-determined leaching adsorption/desorption values. A qualitative approach was used to estimate potential risks to pisci vorus birds.

EPA evaluated modeling information submitted by the registrant. In a non-guideline study submitted to the Agency (Ackerman, D, F Ghillebaert, and MW Glass, 2013: MRID 49040220), Mexel used two modeling approaches to estimate exposures and risks to aquatic organisms downstream of two power plants. The first modeling approach used the site-specific option of the General Population and Ecological Exposure from Industrial Releases module of EFAST to provide screening level estimates of exposures to aquatic organisms and the second approach used the higher tier CE-QUAL-W2 m odel to provide more refined estimates of exposures to aquatic organisms. Mexel consid ered the two power plants they selected for modeling to be atypical and to have the greatest impact.Page 14 of 103 EPA evaluated whole effluent toxicity te sting submitted by the registrant from two facilities, Calvert Cliffs Nu clear Power Plant (CCNPP) and Donald C. Cook Nuclear Power Plant (DCCNPP) conducting efficacy trials with MEXEL 432/0 were submitted by the registrant (MRID 49208816) and evaluated by the Agency; de tails of these studies are provided in Appendix C. CCNPP is located along an estuar ine area of the Potomac River and DCCNPP is located along the shore of Lake Michigan. Both facilities have once th rough cooling systems. The design flow is 3460 million gallons per day at CCNPP and 2405 million gallons per day at
CCNPP.



### 2.0 ENVIRONMENTAL FATE ASSESSMENT

2.1 Product Chemistry and Chemical Structure

ATMD is an alkyl triethylene diamine surf actant (surface acting agent) with an alkyl
chain that contains 8-18 carbons in even increm ents. The predominant alkyl chain constituents (C 12 , C 14 , C 16 , and C 18 ) account for 45.3, 16.2, 9.5, and 11.1 pe rcent of the total mixture, respectively. Taken together, th e four predominant constituents account for 82.1 % of the parent mixture. The remaining diamine compounds (C 8 and C 10 ) account for a total of 9.3 % of the parent mixture (MRID 49040203). Figure 1 belo w contains the structure of the primary compound (C 12 ), which accounts for 45 % of the total diamine mixture.

Figure 1: Chemical Structure of Dodecyl-1,3-propanediamine.

The registrant submitted product chemistry studies for their product which contain information that appears to be us eful for risk assessment. The u ltraviolet (UV) visible absorption spectrum study indicates that the maximum sorp tion is in the range of 202-218 nanometers (nm) of wavelength, with only a small amount of absorption in the 290-350 nm range (MRID 49040202). As a result of this limited UV sorptio n, minimal photodegrada tion by sunlight is expected. The weighted average 1 octanol-water partitioning coeffi cient (log P) of the N-coco-

1 Weighted arithmetic mean of (log P for each compound * percentage in mixture) /91.4 % diamine content. H 3 C N H N H 2Page 15 of 103 1,3-diaminopropane product was 0.2 (unitl ess), but it ranged from -3 (for C 8 alkyl chain) to 2-2.5 (for C 18 alkyl chain) [MRID 49040203]. Based on this log P value, this mixed product can bioconcentrate but is not expe cted to have high bioconcentr ation in aquatic organisms. 2

, 3 The water solubility for the entire product is relativel y low because of the alkyl carbon chain, and is approximately 10 milligrams per liter (mg/l or ppm) (MRIDs 49040204, 48486702).



### 2.2 Summary of Abiotic Environmental Fate Processes

ATMD is stable to hydrolysis at pH 5, 7, and 9 (MRIDs 40062413, 41069001, and 93034010) and is expected to undergo minimal p hotodegradation in water based on minimal sorption of UV light between 290- 800 nm in wavelength (MRID 49040202).



### 2.3 Summary of Biotic Environmental Fate Processes

The registrant has not submitted guideline aquatic metabolism studies for ATMD. Aerobic aquatic metabolism (835.4300) represen ts the water column in a water body while anaerobic aquatic metabolism (835.4400) represents the bottom and suspended sediment. In lieu of aquatic metabolism guideline studies, the regist rant provided literature studies to address the persistence of alkyl amines and de gradates in sediment and water. Information in the literature
studies 4 demonstrated that degradation of al kylamines occurred by deamination followed by beta-oxidation of the alkyl chains, with successi ve formation of alkanal groups (alkane chain with aldehyde functional group) and fatty aci ds (carboxylic acids), which degrade to CO 2 , water, and bacterial biomass. However, none of thes e studies provided estim ates of half-life of alkylamines or their metabolic intermediates, a nd therefore their persiste nce cannot be estimated at this time (MRIDs 49208802, 49208803).



### 2.4 Summary of Environmental Transport Processes

Based on soil sorption studies, ATMD was observed to tightly sorb with whole soil Freundlich adsorption values (Kf) of 14,454-50,898 L/kg and adsorption values normalized for soil organic carbon (Koc) of 696,677 - 4,551,033 L/Kg. In ea ch of the five soils tested, nearly all (>99 %) of ATMD was sorbed w ithin a 24-hour period. Sorption wa s related to cation exchange

2 TG OECD 305 states that a compound having a log P of > 3 does not have “high” lipophilicity

3 http://www.epa.gov/scipoly/sap/meetings/2008/octobe r/305_bioconcentration_flowthrough_fish_test.pdf

4 Cerniglia and Perry (1975), Nguyen et al. (2008), and van Ginkel et al. (2008)Page 16 of 103 capacity (CEC) 5 with a coefficient of determination (r 2) of 0.55 which indicates that sorption is a function of clay content (r 2 =0.16), organic carbon content (r 2 =0.21), and pH (r 2 =0.33) (MRID 49040206).

ATMD bioconcentrated in bluegill sunfish ( Lepomis macrochirus ) with steady state bioconcentration factors of 82-180X, 525-610X, a nd 378-388X for edible, non-edible, and whole fish, respectively. The 50 % depuration times were 17, 8.5-21, and 9.2-30 days for edible, nonedible, and whole fish, respectively (MRID 49040210).



### 2.5 Summary of Environmental Fate in Wastewater Treatment

In a wastewater treatment plant, the primary route of dissipation of ATMD is expected to be sorption to activated sludge. ATMD was str ongly sorbed to activated sludge with Kf values of 39,753 and Koc values of 105,222 L/kg. The extent of sorption increased with time based on 71-92 % sorption by 4-6 hours (mean of 83 %) and 94-98 % sorption by 12-24 hours (mean of 96 %) (MRID 49040205).

ATMD is not expected to degrade rapidl y in water or during wastewater treatment because it was not determined to be readily biod egradable in an OECD 301D Closed Bottle test (MRID 49040207). At 2 mg/l of ATMD, the registra nt reported that 69 % of the theoretical oxygen demand (ThOD) was reached by 28 days, and therefore ATMD should be considered to be readily biodegradable. However, this result does not meet the pass criterion established for this guideline. The OECD 301D test guideline cr iterion for ready biodegr adability in a Closed Bottle test is 60 % of ThOD in a 14-day period, and this 14-day period starts when 10 % of ThOD disappears and must end before day 28 of the test. 6 In the study, 10 % ThOD disappearance occurred at appr oximately 8 days, and the maximum percent ThOD disappearance in any 14-day window was 42 % (from 8-22 days).

The IC 50 value for the ASRI test (MRID 49040218) wa s 22 mg/l with 95 % confidence bounds of 10-30 mg/l.

5 Cation exchange capacity (CEC) is the sum of the negativ e charges in the soil, which is affected by pH, organic carbon, and clay content.

6 P. 3, OECD 301, http://www.oecd.org/chemicalsafe ty/risk-assessment/1948209.pdfPage 17 of 103 

### 2.0 HUMAN HEALTH RISK ASSESSMENT

3.1 Hazard Assessment

For ATMD, the registrant submitted information to address the human health data requirements needed to assess the proposed use. In formation is needed on subchronic toxicity, developmental toxicity, reproductive toxic ity, chronic toxicity, carcinogenicity, and mutagenicity. The information submitted by the registrant consisted of one submitted 90-day oral toxicity study (MRID 49092801) reviewed by the Office of Pesticide Programs’ (OPP) Antimicrobials Division, and summaries of toxicity studies on subchronic (MRID 49208808), developmental (MRID 49208809), reproductive (MRID 49208810), chronic toxicity (MRID 49208811), carcinogenicity (MRID 49208812), and ne urotoxicity (MRID 49208813) cited in a 2008 European risk assessment document (Eur opean Commission, 2008; information submitted under MRID 49208808). The studies cited in th e 2008 European Commission risk assessment were conducted on certain ATMD structural analogs . Toxicity information also consists of a repeated dose toxicity study with developm ental and reproductive screening (MRID 47646101) submitted on coco alkylamines (pc code 900960). The issue of structure-activity is discussed more below. Many of the cited studie s (with the exception of the 90-day and developmental/reproductive screening study men tioned above) are from the open scientific literature and were submitted as summaries only. Summaries of all toxicity studies mentioned above are presented in Appendix B of this risk assessment.

The registrant proposed that ATMD structural analogs (such as those considered in the 2008 European Union risk assessment) should be in cluded as part of the hazard database for assessment of the proposed use of ATMD. The issu e of structure-activity was discussed within the agency. The agency has dete rmined that the data on the AT MD analogs summarized in the 2008 European Commission risk assessment could be considered together with the data on ATMD, as the effects observed from toxicology st udies conducted with these chemicals appear to be similar, and are related to the irritant pr operties of these chemicals. One difference appears
to be the doses at which the effects are observe d, with the diamine chemicals being more potent
than the monoamine chemicals in causing irritant-like effects.

3.2 Dose-Response Assessment

The information submitted for assessment of human health hazard on ATMD consisted largely of summaries of toxicity studies conducte d in experimental animals. As mentioned, many
of these studies were cited from a 2008 Eur opean Union Risk Assessment on certain ATMD
chemicals.Page 18 of 103 OPP has developed and published a guidance document ( http://www.epa.gov/pesticid es/science/lit-studies.pdf ) regarding the adequ acy of scientific literature studies submitted in support of a human health risk assessment. To be considered adequate, information from the open literature sh ould be presented as th e full article and not a summary. All of the cited studies from the 2008 European Commission risk assessment were submitted as summaries only. This hinders a full hazard evaluation and dose-response assessment of the mammalian toxicity data for the proposed use of ATMD.

Table 1 presents endpoints us ed in the ATMD drinking wate r assessment. Lacking full study reports for review, the No Observable A dverse Effect (NOAEL) value of 0.4 milligrams per kilogram per day (mg/kg/day) from the 90- day oral toxicity st udy (MRID 49092801) is used as a conservative endpoint for the assessment of acute and chronic risk from drinking water exposure to ATMD for the proposed use. This en dpoint is conservative because it currently is
the lowest NOAEL value from the database on ATMD chemicals. The acute and chronic assessments are conducted using the same endpoint (0.4 mg/kg/day) and uncertainty factor (100). An extra uncertainty factor for extrapolation to assess chronic risk is not needed, based on the main effects of the chemical being portal-of-en try type effects (e.g. i rritation) and that under relevant exposure conditions, these effects would not be expected to occu r at lower doses with increased duration of exposure.

This approach is also consistent with the approach to assessment of chemicals such as ATMD that show primarily portal-of-entry effect s (irritation, corrosion). Re gulation of hazard on such effects is considered protec tive of any systemic effects that might occur and is consistent with previous decisions made in OPP for chemi cals whose effects are primarily portal-of-entry
effects.Page 19 of 103 Table 1: Endpoints for use in ATMD Drinking Water Assessments
Exposure Scenario Point of Departure Uncertainty Factors RfD. Level of concern for risk
assessment Study and Toxicological Effects
Acute and Chronic Dietary 0.4 mg/kg/day 100 (10x interspecies extrapolation, 10x intra-species variation) aRfD=aPAD= 0.004 mg/kg/day

cRfD=cPAD= 0.004 mg/kg/day 90-day oral toxicity study in rodents (MRID 49092801)

LOAEL = 1.5 mg/kg/day, based on decrease in body weight gain and food consumption in
males and histopathology changes in the male
and female mesenteric lymph node, spleen, bone marrow (sternum)
and trachea

3 .2.1 FQPA Considerations

The database for FQPA assessment of ATMD currently consists of the OECD combined repeat dose reproductive/ developmental study on the representative compound that is a mixture of C8-C18 primary amines derived from oleochem icals. The Executive Summary for the study is included in Appendix B.

There was no increased susceptibility to the offspring of rats following prenatal and postnatal exposure in the OECD 422 reproductive/ developmental screening study. Decreased pup body weight was observed at 40 and 80 mg/kg/da y where maternal/paternal toxicity was manifested as microscopic lesions in the st omach, jejunum, thymus, and lymph nodes at 20, 40, and 80 mg/kg/day. Since the rat reproduction/deve lopmental study identified a clear NOAEL of 20 mg/kg/day for offspring effects, and the parental NOAEL for stomach/jejunum/thymus/lymph node lesions for the dietary risk assessment is protective of the offspring effects, there are no residual concerns for toxicity.

There are also no residual uncertainties id entified in the exposure databases. Dietary exposure assessments are considered to be cons ervative. The drinking water assessment is notPage 20 of 103 likely to underestimate exposure to any subpopula tion, including those comp rised of infants and children. Therefore, the FQPA factor can be reduced to 1x.

The total uncertainty factor for de rivation of the RfD is therefore 100.



### 3.3 Dietary Assessment

ATMD as a group have a currently registered use pattern as antimicr obial pesticides in industrial process water sy stems (oilfield injection water syst ems, industrial recirculating water cooling towers, and well comple tion and workover fluids).

For the registration action discussed in this risk assessment, the proposed use of ATMD to control bio-fouling in once-through and reci rculating cooling towers constitutes a new use where human exposure through drinking water can be expected to occur. Thus a risk assessment from exposure to ATMD in drinking water is necessary. The registrant has proposed the NOAEL of 0.4 mg/kg/day from the submitted 90-day oral toxicity study on ATMD as the endpoint for
use in the risk assessment. This value was used for deriving the acute a nd chronic reference dose (aRfD and cRfD respectively) to assess risks from exposure to AT MD in drinking water for this

assessment.

3.2.2 Dietary Exposure and Risk Analysis

Initially, surface water concentrations of ATMD from the proposed use were estimated based on results from the General Population an d Ecological Exposure from Industrial Releases Module of the Exposure and Fate Assessment Screeni ng Tool (E-FAST). Results of this analysis (shown in Table 2 below) shows the surface water concentrations based the lowest 30 consecutive day average flow th at occurs [on average] once ev ery 5 years (30Q5) and harmonic mean (i.e., inverse mean of reciprocal da ily arithmetic mean flow values) for the 10 th and 50 th percentile distributions of stream flow to plant flow assuming no removal of active ingredient prior to its discharge in effluent. The 10 th percentile exposure repr esents a high-end scenario where plant flow contributes considerable vo lume relative to the stream flow. The 50 th percentile exposure represents a median or more t ypical ratio of stream fl ow to plant flow. For completeness, an estimated drinking water c oncentration (EDWC) of 42.5 ppb was added to represent the worst case end-of-pipe scenario.Page 21 of 103 For the determination of drinking water exposures to humans, the surface water concentration from E-FAST based on the 30Q5 flow value was used to represent acute exposure
and the harmonic mean flow value was us ed to represent ch ronic exposure.

Using the surface water concentrations and e nd of pipe concentration shown in Table 2, acute and chronic dietary (drink ing water only) human exposures were calculated for ATMD using the Dietary Exposure Evaluation Model software with the Food Commodity Intake Database (DEEM-FCID) Version 3.16. This so ftware uses 2003-2008 food consumption data from the U.S. Department of Agriculture’s (USDA’s) National Health and Nutrition Examination Survey, What We Eat in America, (NHANES/WWEIA). The data are based on the reported consumption of more than 20,000 indivi duals over two non-consecutive survey days. For chronic exposure assessment, consumption da ta are averaged for the entire U.S. population and within population subgroups. However, for acute exposure assessment, consumption data are retained as individual consumption even ts. Based on analysis of the 2003-2008 WWEIA consumption data, which took into account di etary patterns and su rvey respondents, AD concluded that it is most appropriate to re port exposures and risks for the following population subgroups: the general U.S. population, all infants (<1 year old), childr en 1-2, children 3-5, children 6-12, youth 13-19, adults 20-49, fema les 13-49, and adults 50-99 years old.

For a chronic dietary (drinking water in this case) exposure assessment, an estimate of the
residue level in each food or food-form on the food commodity residue list is multiplied by the average daily consumption estimate for that food/f ood form to produce a residue intake estimate. The resulting residue intake estimate for each f ood/food form is summed w ith the residue intake
estimates for all other food/food forms on the comm odity residue list to arrive at the total average estimated exposure. Exposure is expres sed in mg/kg body weight/day and as a percent of the reference dose (acute and chronic RfD). This procedure is performed for each population subgroup.

For an acute exposure assessment, individua l one-day food consumption data are used on an individual-by-individual basis. The repor ted consumption amounts of each food item can be multiplied by a residue point estimate and summed to obtain a total daily pesticide exposure for a deterministic exposure assessment, or “matched” in multiple random pairings with residue values and then summed in a probabilistic assessment. The resulting distribution of exposures is expressed as a percentage of th e RfD on both a user (i.e., only t hose who reported eating relevant commodities/food forms) and a per-capita (i.e., those who re ported eating the relevant commodities as well as those who did not) basis. In accordance with policy, per capita exposure and risk are reported for analyses perform ed at all levels of refinement.

Note that water concentrations were incorporated in DEEM-FCID into the food categories “water, direct, all sources” and “water, indirect, all sources” for the purposes of this

assessment.Page 22 of 103 Table 2: Estimated Drinking Water Con centrations (EDWCs) of ATMD for Surface Water using the E-FAST Model

Drinking Water
Source Scenario Acute Concentration based on 30Q5 Stream
Flow Distribution (μg/L) Chronic Concentration based
on Harmonic Mean Stream
Flow Distribution (μg/L)

Surface Water (E-FAST) End-of-pipe 42.5 42.5
Once through cooling system
0% removal 10th percentile concentration 18.25 4.62

Once through cooling syatem
0% removal 50th percentile concentration 0.22 0.11

Recirculating cooling tower
0% removal 10th percentile concentration 8.39 2.12

Recirculating cooling tower
0% removal 50th percentile concentration 0.098* 0.049*

* These scenarios were not modeled with DEEM becaus e exposures with higher Estimated Drinking Water Concentrations (EDWCs) produced negligible risk estimates.

Results of the exposure and risk analyses for the propos ed ATMD use are presented below in Tables 3 through 6. The highest expos ed sub-population for each analysis is bolded.

Table 3: Summary of Acute and Chronic Di etary Exposure and Risk Analyses for ATMD (End-of-pipe water concentration)

Population Subgroup Acute Chronic

Estimated Exposure (95 th Percentile) (mg/kg/day) Estimated Risk, % aRfD MOE (LOC =

100) Estimated Exposure (average) (mg/kg/day) Estimated Risk, % cRfD MOE (LOC =

100)

U.S. Population 0.002317 58 170 0.000890 22 450

All infants 0.007258 180 55 0.002295 57 170

Children 1-2 yrs 0.003574 89 110 0.001284 32 310

Children 3-5 yrs 0.002900 72 140 0.001082 27 370

Children 6-12 yrs 0.00216 55 180 0.000780 20 510Page 23 of 103 Population Subgroup Acute Chronic

Estimated Exposure (95 th Percentile) (mg/kg/day) Estimated Risk, % aRfD MOE (LOC =

100) Estimated Exposure (average) (mg/kg/day) Estimated Risk, % cRfD MOE (LOC =

100)

Youth 13-19 yrs 0.001930 48 210 0.000649 16 620

Adults 20-49 yrs 0.002280 57 180 0.000888 22 450

Adults 50+ yrs 0.002031 51 200 0.000878 22 460

Females 13-49 yrs 0.002313 58 170 0.000885 22 450

Table 4: Summary of Acute and Chronic Diet ary Exposure and Risk Analyses for ATMD (Once through cooling system, 0% removal, 10th percentile ratio of stream flow to plant flow)

Population Subgroup Acute Chronic

Estimated Exposure (95 th Percentile) (mg/kg/day) Estimated Risk, % aRfD MOE (LOC =

100) Estimated Exposure (average) (mg/kg/day) Estimated Risk, % cRfD MOE (LOC =

100)

U.S. Population 0.000995 25 400 0.000097 2.4 4100

All infants 0.003117 78 130 0.000249 6.2 1600

Children 1-2 yrs 0.001535 38 260 0.000140 3.5 2900

Children 3-5 yrs 0.001245 31 320 0.000118 2.9 3400

Children 6-12 yrs 0.000951 24 420 0.000085 2.1 4700

Youth 13-19 yrs 0.000829 21 480 0.000071 1.8 5600

Adults 20-49 yrs 0.000979 24 410 0.000097 2.4 4100

Adults 50+ yrs 0.000872 22 460 0.000095 2.4 4200

Females 13-49 yrs 0.000993 25 400 0.000096 2.4 4200Page 24 of 103 Table 5: Summary of Acute and Chronic Diet ary Exposure and Risk Analyses for ATMD (Once through cooling system, 0% removal, 50th percentile ratio of stream flow to plant flow)

Population Subgroup Acute Chronic

Estimated Exposure (95 th Percentile) (mg/kg/day) Estimated Risk, % aRfD MOE (LOC =

100) Estimated Exposure (average) (mg/kg/day) Estimated Risk, % cRfD MOE (LOC =

100)

U.S. Population 0.000001 <1 400000 0.000000 <1 NA

All infants 0.000004 <1 100000 0.000001 <1 400000

Children 1-2 yrs 0.000002 <1 200000 0.000000 <1 NA

Children 3-5 yrs 0.000002 <1 200000 0.000000 <1 NA

Children 6-12 yrs 0.000001 <1 400000 0.000000 <1 NA

Youth 13-19 yrs 0.000001 <1 400000 0.000000 <1 NA

Adults 20-49 yrs 0.000001 <1 400000 0.000000 <1 NA

Adults 50+ yrs 0.000001 <1 400000 0.000000 <1 NA

Females 13-49 yrs 0.000001 <1 400000 0.000000 <1 NA

Table 6: Summary of Acute and Chronic Di etary Exposure and Risk Analyses for ATMD (Recirculating cooling tower, 0% removal, 10th percentile ratio of stream flow to plant flow)

Population Subgroup Acute Chronic

Estimated Exposure (95 th Percentile) (mg/kg/day) Estimated Risk, % aRfD MOE (LOC =

100) Estimated Exposure (average) (mg/kg/day) Estimated Risk, % cRfD MOE (LOC =

100)

U.S. Population 0.000457 11 880 0.000044 1.1 9100

All infants 0.001433 36 280 0.000114 2.9 3500

Children 1-2 yrs 0.000705 18 570 0.000064 1.6 6300

Children 3-5 yrs 0.000572 14 700 0.000054 1.3 7400Page 25 of 103 Population Subgroup Acute Chronic

Estimated Exposure (95 th Percentile) (mg/kg/day) Estimated Risk, % aRfD MOE (LOC =

100) Estimated Exposure (average) (mg/kg/day) Estimated Risk, % cRfD MOE (LOC =

100)

Children 6-12 yrs 0.000437 11 920 0.000039 1.0 10000

Youth 13-19 yrs 0.000381 10 1100 0.000032 <1 13000

Adults 20-49 yrs 0.000450 11 890 0.000044 1.1 9100

Adults 50+ yrs 0.000401 10 1000 0.000044 1.1 9100

Females 13-49 yrs 0.000457 11 880 0.000044 1.1 9100

The above calculations of exposure and risk for ATMD represent conservative scenarios for both the once-through and re circulating cooling tower uses, because of the following assumptions: (1) none of the chemical is assume d to be removed from water; (2) there is no sorption (and hence removal) of the chem ical to solids in the water; (3) the 10 th percentile of exposure represents a conservative es timate of drinking water exposures.

One scenario analyzed above showed a risk of concern. Using the end-of-pipe concentration of 42.5 ppb, a MOE < 100 was calculate d for all infants for acute exposure at the
95 th percentile. The Agency does not consider this to be a likely exposure scenario since the
label states that this is for us e in non-potable waters and the end of pipe concentration does not account for dilution, sorption or degradation. No mitigation measures are needed for this exposure scenario.



### 3.3 Residential Non

­ Dietary Assessment

Because the ATMD is proposed for use only in non-potable industrial water systems, residential exposures ar e not anticipated.Page 26 of 103 

### 3.4 Aggregate and Cumulative Exposure

3.4.1 Aggregate Exposures

In order for a pesticide registration to con tinue, it must be shown that the use does not
result in “unreasonable adverse effects on the en vironment.” Section 2 (bb) of FIFRA defines this term to include “a human dietary risk from re sidues that result from a use of a pesticide in or on any food inconsistent with standard under section 408...” of FFDCA. Consequently, even though no pesticide tolerances have been establ ished for ATMD the stan dards of FQPA must still be met. As mandated by the FQPA amen dments to FIFRA and the Federal Food, Drug and Cosmetic Act (FFDCA), the Agency must consider total aggregate exposu re from food, drinking
water and residential sources of exposure to ATMD.

Acute aggregate dietary assessment would in clude both acute dietary and drinking water exposures. Chronic aggregate dietary assessmen t would include chroni c exposure through diet and drinking water. For the proposed new us e of ATMD, there are pot ential exposures in drinking water. There are no expos ures in food. An aggregate assessment is therefore not necessary, and the calculated drinking water risk s shown above represent the total exposure and risk for ATMD from the proposed use.

3.4.2 Cumulative Exposures

With respect to cumulative exposure, unlike other pesticides for which EPA has followed a cumulative risk approach based on a common mechanism of toxicity, EPA has not made a common mechanism of toxicity finding as to AT MD and any other substances and ATMD does not appear to produce a toxic metabolite produced by other substances. For the purposes of this preliminary risk assessment, therefore, EP A has not assumed that ATMD has a common mechanism of toxicity with other substances . For information regarding EPA’s efforts to
determine which chemicals have a common mech anism of toxicity and to evaluate the cumulative effects of such chemicals, see http://www.epa.gov/pesticides/cumulative/

.



### 3.5 Occupational Exposure

There is a potential for occupational derm al and inhalation exposure during the mixing and loading of ATMD into industr ial cooling water systems. This potential is minimal; however,Page 27 of 103 if closed loading and delivery systems are use d. The directions on th e proposed product label suggest that ATMD will be applied using clos ed loading systems although the language is not clear because it specifies "closed delivery system s" rather than "closed loading and delivery systems". If the label could be revised to spec ify "closed loading and de livery systems" then it could be assumed that occupational exposures w ould be minimal and it would not be necessary
to conduct a risk assessment to quantify these exposures.

Post application inhalation exposures to ATMD as a vapor is expected to be minimal because the vapor pressure of ATMD is less than 1 x 10 -4 mm Hg, which is the cutoff that EPA typically uses to determine if inhalation exposure to vapors need s to be assessed. Post application inhalation exposure to cooling water aerosols containing ATMD is also expect ed to be minimal because of the low application rate of 4.0 ppm.



### 3.7 Human Health Risk Characterization

The assessment of exposure to humans fr om the proposed use of ATMD relies upon
estimates of surface water concentrations as de termined in the E-FAST model. These surface
water concentrations are consid ered conservative estimates of exposure, as there is the assumption of no sorption to solids contained w ithin water and that there is no removal of ATMD through wastewater treatment. Using th e surface water concentration estimates, the
DEEM-FCID model is used to calculate human e xposure and risk to iden tified subpopulations of
concern. The calculation of risk is also base d on the use of a conservative NOAEL value of 0.4 mg/kg/day from a 90-day oral toxi city study in rats, to which a st andard uncertainty factor of 100 (10x for species extrapolation, 10x for intra-species variation) is applied. This adds additional
conservatism to the risk assessment.

The use of these conservative assumptions and the resulting lack of concern for risk to humans are considered to be adequate in a ddressing uncertainties in human hazard and exposure for this risk assessment. Any refinement to the as sessment would not likely result in any risks of concern, considering the alrea dy large margins of exposure id entified in the present risk
assessment. There would need to be considerab ly higher human exposure and/or a considerably
lower NOAEL value for ATMD for there to be ri sks of concern in this assessment. Higher human exposure may arise through additional us es of ATMD, and lower NOAEL values from
future review of the hazard database for ATMD (including new data).Page 28 of 103 

### 3.0 ECOLOGICAL RISK ASSESSMENT

This section presents the ecological eff ects data and exposure assessment for ATMD conducted by the Agency. The exposure estimates and toxicity effects data are integrated in order to provide estimates of risks to ecological organisms. The risks from the proposed cooling water uses of ATMD are then characterized taking into consideration the agency’s estimates of risk and other weights of evidence both quantitati ve and qualitative (e.g., w hole effluent toxicity testing, site specific risk mode ling submitted by the registrant, dilution factors, assumptions and limitations).



### 4.1 Selected Ecological Toxicity Endpoints

Ecological effects data are used as measures of direct and indirect effects to aquatic and terrestrial organisms. Acute and chronic toxi city data from registrant-submitted studies
conducted in accordance with the 850 OCSPSP Ha rmonized Test Guidelines, along with values modeled using interspecies correlation estima tion methods, and acute-to- chronic ratios (ACR) were used to evaluate the potenti al direct and indirect effects of ATMD to plants and animals. All data requirements and available ecotoxic ity endpoints from studies submitted by registrants are tabulated in Appendix C. Additionally, as described in Appendix C, Web-ICE (EPA 2013) has been used to predict the acu te toxicity to the fathead minnow . ACRs (EPA 2010) also have been extrapolated to estimate chronic No Obse rvable Adverse Effects Concentrations (NOAECs)
for freshwater fish and estuarine/marine fish and invertebrates. For each receptor group and measure of effect, OPP uses the most sensitiv e of these endpoints for assessing risk. The endpoints selected for the ri sk assessment for ATMD are provided in Table 7.

Table 7: Effects Endpoints Selected for Assessing Ecological Risks to ATMD

Receptor Group Surrogate Species Risk Scenario Toxicity Endpoint Reference

Freshwater fish Rainbow trout Acute 96-h LC50 = 120 μg ai/L 41786606 Chronic NOAEC = 4 μg ai/L a See Appendix C

Freshwater
invertebrates Mollusk Acute 48-h LC50 = 19 μg ai/L Use of estuarine/ marine mollusk value as a surrogate

Water flea Acute 48-h EC50 = 51 μg ai/L 41786602 Chronic NOAEC = 16 μg ai/L 49040208

Freshwater benthic invertebrates Midge Subchronic 10-day EC50 = 188 mg ai/kg sediment 49040211

Amphipod Subchronic Data gap
Estuarine/marine fish Atlantic silverside Acute 96-h LC50 = 155 μg ai/L 41786604Page 29 of 103 Receptor Group Surrogate Species Risk Scenario Toxicity Endpoint Reference

Chronic NOAEC = 5 μg ai/L b See Appendix C

Estuarine/marine invertebrates Mollusk Acute 48-h EC50 = 19 μg ai/L 41786603

Shrimp Acute 96-h LC50 = 61 μg ai/L 41786605 Chronic NOAEC = 19 μg ai/L c See Appendix C Estuarine/marine benthic invertebrates Chironomid sp. Subchronic 10-day EC50 = 303 mg ai/kg sediment 49040212

Algae Green algae Nonlisted EC50 = 5.2 μg ai/L 49040216 Listed NOAEC = 2.4 μg ai/L Aquatic vascular plants Duckweed Nonlisted EC50 = 123 μg ai/L 49040213 Listed NOAEC = 20 μg ai/L Birds Mallard duck Acute LD50 = 0.24 mg/kg-bw 47013023

a The rainbow trout was the most acutely sensitive fish species tested but no chronic data are available for this species; therefore, a chronic NOAEC was estimated for the trout. The chronic value was extrapolated using an ACR (EPA 2010) of 29 (see Appendix C) as determined by using the fathead minnow acute LC50 (328 μg ai/L as predicted from Web-ICE; EPA 2013, see Appendix C) divided by the fathead minnow chronic NOAEC (11 μg ai/L), and then applying this ratio to the acute rainbow trout LC50 (120 μg ai/L).

b The chronic NOAEC is extrapolated us ing the ACR (29) for freshwater fish (see footnote a) and applying this ratio to the acute LC50 of 155 μg ai/L for the Atlantic silv erside; the extrapolation assu mes a common chronic mode of action for freshwater and estuarine/marine fish.

c The chronic NOAEC is extrapolated from th e ACR (3) for freshwater invertebrates ( D. magna acute LC50 = 51 μg ai/L, divided by the D. magna chronic NOAEC = 16 μg ai/L) and applying this ratio to the acute toxicity for the estuarine/marine crustacean (mysid shri mp LC50 = 61 μg ai/L); the extra polation assumes a common chronic mode of action for freshwater and es tuarine/marine crustaceans.

4.1.1 Effects to Wastewater Treatment Plant Microorganisms

An Activated Sludge Respiration Inhibiti on (ASRI) study is used to determine the potential of a chemical substance to directly harm the microorganisms pr esent in the activated sludge treatment process at conventional wastewater treatment facilities. Results from an ASRI study are used to determine the potential risk of inhibiting ac tivated sludge microorganisms, thereby allowing pollutants to pass through to the environment as a result of untreated or partially treated wastewater. AS RI test results are also used to determine what type of wastewater treatment plant bi odegradation testing would be appropriate, such as a ready biodegradability test or an activated sludge biodegradation simulation test.

The Activated Sludge Respiration Inhibition study (Schaefer E and A Ponizovsky (2012); MRID 49040218; see Appendix A for complete citatio n) provides supplemental data but is not acceptable because the confidence bounds for the IC 50 are too wide. For the test substance, ATMD, the reported IC 50 was 22 mg/l with a 95 % confiden ce interval of 10-30 mg/l. Additional sampling at concentrations of the te st substance between the 95% confidence bounds of 10 and 30 mg/l would be needed to provide a more accurate determination of the IC 50 . The percent respiration inhi bition measured ranged from -1.5 % at 10 mg/l to 77.8 % at 30 mg/l withPage 30 of 103 no concentrations measured in between. As a result, it cannot be concluded with reasonable confidence that the activated sludge IC 50 is 22 mg/L.



### 4.2 Summary of Ecological Exposure Assessment Approach

Three basic approaches were used to estimate potential risks from exposures of ecological organisms to ATMD: a quantitative approach, a semi-quantitative approach, and a qualitative approach. A quantitative approach was used to estimate exposures to freshwater fish
and invertebrates in the surface water column and to estimate exposures to freshwater benthicdwelling organisms. A semi-quantitative approach was used to estimate exposures to estuarine/marine organisms in the surface water column and to estimate exposures to estuarine/marine benthic-dwelling organisms. A qualitative approach was used for estimating exposures to piscivorus birds and mammals.

Based on information from the MEXEL 432/0 product label, all estimates of ecological
risk are based on maintenance of 2.5 ppm residual Mexel 432/0. Th e concentration of the active ingredient in the produc t is 1.7 percent; based on maintenan ce of 2.5 ppm product residual, this corresponds to 42.5 ug/L ATMD.

The exposure scenarios that form the basis of this ecological ri sk assessment include exposures from releases to surface water from:

 large-size recirculating cooling towers;

 moderate-size recirculati ng cooling towers; and

 once-through coo ling systems.

For recirculating cooling towers, exposures from releases to surface water were estimated with
and without wastewater treatme nt. Exposures based on no wastewater treatment assumed no removal of the active ingredient. Exposures based on wastewater treatment were estimated assuming 71 percent removal during wastewat er treatment and 92 percent removal during wastewater treatment. The assumption of 71 pe rcent removal during wastewater treatment is based on removal expected from sorption to activ ated sludge as a result of treatment in the activated sludge basin for 4 hours. The assu mption of 92 percent removal during wastewater treatment is based on removal expected from sorp tion to activated sludge as a result of treatment in the activated sludge basin for 6 hours. The ra nge of 4 to 6 hours assumed for treatment in an activated sludge basin is cons idered typical for activated sl udge treatment in conventional wastewater treatment systems. These estimates of percent removal are based on experimental results reported in the activated sludge sorp tion isotherm study submitted by the registrant and are based on sorption of the ac tive ingredient by activated sl udge after 4 and 6 hours underPage 31 of 103 conditions that simulate an activated sludge basin (MRID 49040205; Schaefer, E and A Ponizovsky (2012); (See Appendix A for complete citation)).

For once-through cooling systems, it was assu med that no treatment of effluent (i.e., no removal of active ingredient) occurs prior to discharge to surface water.

The general methodology used to estimate water column and sediment exposures to ecological organisms from release of ATMD from once-through and recircul ating cooling towers in presented in Appendix E.

4.2.1 EPA’s Estimation of Exposure of Freshwater Fish and Invertebrates to ATMD
in the Water Column

The probabilistic dilution model (PDM) opti on of The General Population and Ecological Exposures for Industrial Releases module (hereina fter referred to as the Industrial Releases Module) of E-FAST was used to estimate magn itude of exposure of aquatic organisms in the surface water column to ATMD, the active ingred ient present at 1.7 percent in the product, Mexel 432/0. Key input parameters needed to run this module in clude the environmental release to surface water in kg/site/day, percent removal of active ingredient during wastewater treatment, and concentrations of concern for aquatic organi sms. Model outputs are expressed as days per year of exceedance of concentra tions of concern for aquatic organisms. Estimates of exposure were developed for both a high-end scenario (i.e., 10 th percentile of the distribution of the ratio of 7Q10 stream flows to plant flows) and for an av erage case scenario (i.e., the median of the distribution of the ratio of 7Q 10 stream flows to plant flows) . The 7Q10 is the lowest 7 consecutive-day stream flow over a 10-year perio d. A detailed discussion of the PDM approach is presented in Appendix D. A detailed disc ussion of the methodology for estimating potential risks from exposure of aquatic organisms to ATMD is presented in Appendix D.

The following information appears on the proposed MEXEL 432/0 product label:

“MEXEL 432/0 is to be used for the control of biofouling, including zebra mussels and clams in once-through cooling and cooling tower circuits with closed delivery systems for non-potable
industrial freshwater and sea wa ter systems. The product may be applied to maintain clean systems or to treat systems that are already f ouled. Normal frequency of treatment is once per day or as needed to maintain control. The amou nt of the daily dose is determined by the circuit characteristics. The daily dose is 4.0 ppm for 30 minutes with a residu al concentration of 2.5 ppm.”. The concentration of active ingredient in the product is reported on the product label to be 1.7 percent; based on maintenance of 2.5 ppm product residual, this corresponds to 42.5 ug/L
ATMD.Page 32 of 103 All estimates of ecological risk are ba sed on maintenance of 2.5 ppm residual MEXEL 432/0 throughout a 24-hour period. Although th e product label indicat es that the normal frequency of treatment is once per day, it also stat es that the product can be applied as needed to
maintain control and that the amount of th e daily dose is determined by the circuit characteristics. As a result, the label specifies no upper limit on the frequency of treatment on a daily basis. For the purpose of estimating e xposures to ecological organisms, the Agency assumed that a 2.5 ppm residual is mainta ined throughout a 24-hour period. Under circumstances in which only a single dose woul d be applied for 30 minutes daily and a product residual of 2.5 ppm would be maintained th roughout a 24-hour period, these estimates of exposure would represent peak e xposures of ecological organism s to ATMD used in cooling

towers.

In site-specific modeling results subm itted by Mexel to the Agency (MRID 49040220; Ackerman, D, F. Ghillebaert, and M.W. Glass, 2013; (See Appendix E for the complete citation)), the registrant estimated a daily envi ronmental loading based on the assumption that a 30-minute dose of product, corresponding to a ma intenance dose of product of 2.5 ppm (i.e., 42.5 ug/L ATMD), would be maintained over a 24-ho ur period. Normalizing an environmental loading over a 24-hour period could considerably underestimate potential exposure, especially given that the label does not pr ovide an upper limit on the fre quency of application of the product on a daily basis and that the label sp ecifies maintenance of a 2.5 ppm residual of
MEXEL 432/0.

4.2.2 EPA’s Estimation of Exposure of Freshwater Benthic Invertebrates to ATMD in
Sediments

Estimates of potential exposure to freshwat er benthic invertebrates were derived from
estimates of concentrations of ATMD in fr eshwater benthic sediments. Estimates of
concentrations of ATMD in sediment were deri ved from data on leaching adsorption-desorption
to soil and surface water concentrations estimat ed from the Industrial Releases module of EFAST. The methodology used to estimate concentr ations of ATMD in fr eshwater and sediments are presented in Appendix F. Table 8 presents estimates of concentr ations of ATMD in
freshwater benthic sediments fo r once-through cooling systems, large-size cooling towers, and moderate-size cooling towers based on 10 th and 50 th percentile 7Q10 surface water
concentrations estimated from the I ndustrial Releases module of E-FAST.Page 33 of 103 Table 8: Estimated Concentrations of ATMD in Freshwater Benthic Sediment Based on 10th and 50th Percentile Surface Water Concen trations Estimated from the General Population Exposures and Industria l Releases Module of E-FAST
Cooling Tower Scenario 10 th Percentile 7Q10 Surface Water Concentration (ug/L) Sediment Concentration based on 10 th Percentile 7Q10

A(mg/kgsediment) 50 th Percentile 7Q10 Surface Water Concentration (ug/L) Sediment Concentration based on 50 th Percentile 7Q10 A(mg/kgsediment)

Once-Through Cooling Tower (2 MGD) with No Treatment 30.98 1053.8 0.31 10.54

Large-Size Recirculating Cooling Tower (144 MGD)with No Treatment14.23 484 0.14 4.76

Large-Size Recirculating Cooling Tower with 71 Percent Removal During Wastewater Treatment 4.21 143.2 0.042 1.44

Large-Size Recirculating Cooling Tower with 92 Percent Removal During Wastewater Treatment 1.16 39.5 0.012 0.41

Moderate-Size Recirculating Cooling Tower (2.88 MGD) with No Treatment 0.28 9.52 0.0028 0.095

Moderate-Size Recirculating Cooling Tower with 71 Percent Removal During Wastewater Treatment 0.081 2.77 0.00082 0.028

Moderate-Size Recirculating Cooling Tower with 92 Percent Removal During Wastewater Treatment 0.023 0.78 0.00023 0.0078

A Sediment concentration was estimated using the relationship between water concentration and sediment/soil K f
. The method is discussed in Appendix.

4.2.3 EPA’s Estimation of Exposure of Estuarine/Marine Fish and Invertebrates to
ATMD in the Water Column

Since estuarine and marine water bodies ar e not flowing water bodies and have no stream flows associated with them, the probabilistic dilution mode l (PDM) option of The General Population and Ecological Exposures for Industrial Releases module (hereina fter referred to as the Industrial Releases Module) of the Exposure and Fate Assessment Screening Tool (E-FAST) is not an appropriate tool for es timating exposures to estuarine/ma rine fish and invertebrates inPage 34 of 103 the water column. Therefore, the worst case scenario of once-through cooling systems with no
treatment and an associated concentration of AMTD at the discharge point (42.5 μg ai/L) are used as an upper-bound scenario to determine if estuarine/marine animals and plants might potentially be at risk. Based on this scenari o, for those receptor groups for which risk quotients are exceeded, dilution factors can be calculated to determine the concentration of concern below which exposure would not be likely to be of c oncern for listed and nonlisted estuarine fish and invertebrates (e.g., crustaceans, gastropods) and for algae.

4.2.4 EPA’s Estimation of Exposure of Estuarine/Marine Benthic Invertebrates to
ATMD in Sediments

Exposure of estuarine/marine benthic inverteb rates to ATMD is assumed to be primarily from ATMD present in benthic sediments., As with estuarine/marine water column concentrations, an upper bound estimat e of exposure based on a resi dual concentration of ATMD at the discharge point (42.5 μg ai/L) is used to derive concentrations of ATMD in sediments and to determine if estuarine/marine benthic organi sms might potentially be at risk. For this scenario, the estimated estuarine sediment concentration is 1445.7 mg ai/kg sediment.

4.2.5 EPA’s Estimation of Exposures to Piscivorous Birds and Mammals

Upper bound exposures to piscivorus birds were based on an end-of-pipe discharge concentration of 42.5 ug/L ATMD and a whole- fish bioconcentration factor of 378-388X.

4.2.6 Mexel’s Estimation of Exposure to ATMD Released from Cooling Towers and
Once

­ Through Industrial Cooling Water Systems

In a non-guideline study submitted to the Ag ency (Ackerman, D, F Ghillebaert, and M.W. Glass, 2013: MRID 49040220), Mexel used two modeling approaches to estimate exposures and risks to aquatic organisms downstr eam of two power plants. The first modeling approach used the site-speci fic option of the General Popu lation Exposures and Industrial Releases module of E-FAST to provide screen ing level estimates of exposures to aquatic organisms and the second approach used the hi gher tier CE-QUAL-W2 model to provide more refined estimates of exposures to aquatic organisms. Mexel c onsidered the two power plants they selected for modeling to be atypical and to have the greatest impact. One power plant, the Hammond Power Plant near Rome, Georgia was select ed to be representati ve of the distribution
of facilities in Standard Industrial Classifi cation Code (SIC) 4911 (i.e ., steam electric powerPage 35 of 103 plants); Mexel reports that th is power plant was in the 95 th percentile of all power plant discharges and that its discharge flow of 2082 million liters per day (MLD) was approximately equal to the 7Q10 flow of the Coosa Rive r downstream of the plant (i.e., 2927 MLD), representing a realistic case where the dilutive capacity of the receiving water would be at a minimum. The second power plant, the Crockett Power Plant near Girvin, TX was selected by Mexel to investigate the impacts of using ATMD at a smaller power plant on a smaller stream, the Pecos River; Mexel reports th at the discharge flow from this power plant, 5.29 MLD was in
the 37 th percentile of the di stribution of power plants and that the 7Q10 flow of the Pecos river downstream of the plant is 5.24 MLD (mean stream flow is 1674 MLD).

Mexel assumed that the product would be a pplied over a 30-minute period to achieve a maintenance concentration of ATMD of 42.5 ug/L . Mexel estimated that this concentration would result in 1.04 kg/day being released to surface water from the Hammond Power Plant and 0.00468 kg/day being released to surface water from th e Crockett Power Plant. The loadings in kg/site/day used as inputs to the Industrial Releases model were normalized over a 24-hour period and reduced to reflect a 44 percent “dema nd” that was representative of the range of “immediate demands” from 21 to 86% for the formulated end use product (EP).

EPA’s interpretation of these modeling result s is discussed in the Risk Characterization
section of this risk assessment.



### 4.3 Estimation of Risks to Aquatic Organisms

Risk estimation integrates the results of the exposure and ecotoxicity data to evaluate the likelihood of adverse ecological eff ects. There are generally two approaches used in assessing risks from industrial process and water systems, a risk quotient (RQ) me thod and a probabilistic method. These two basic approaches are discusse d in Appendix D. The probabilistic approach was used to estimate potential risks to freshwater organisms. The risk quotient method was used to estimate potential risks to bot h freshwater and estuarine/marine benthic invertebrates, and to estuarine/marine organisms. In addition, for ma rine/estuarine organisms, dilution factors that would be needed to mitigate exceedance of concentrations of concern were estimated. A qualitative approach was used to estimate potential risks to piscivorus birds.

4.3.1 Estimation of Risks to Freshwater Organisms Exposed to ATMD in the Water
Column

Potential risks to freshwater aquatic organisms from expos ure to ATMD were estimated for the following scenarios:Page 36 of 103  moderate-size recirculating cooling to wers (2000 gallons per minute or 2.88 million gallons per day (MGD) recirculation rate);

 large-size recirculating cooling towers (100,000 gallons per minute or 144 million gallons per day); and

 once-through cooling systems (intak e flows of 2, 20, 50, and 100 MGD)

Moderate-Size Recircula ting Cooling Towers

Tables 9 through 11 present estimates of numb ers of days per year of exceedance of concentrations of concern (COCs) for freshw ater organisms downstream of moderate-size recirculating cooling towers. Table 9 presents estimates of the number of days per year of exceedance of acute COCs for freshwater organi sms, Table 10 presents estimates of the number of days per year of exceedance of COCs for en dangered/listed freshwater organisms, and Table 11 presents estimates of the number of days per year of exceedance of chronic COCs for
freshwater fish and invertebrates.

Table 9: Estimates of Numbers of Day P er Year of Exceedance of Acute COCs for Freshwater Organisms Downstream of Modera te-Size Recirculating Cooling Towers (0.0029 kg/site/day release of ATMD before treatment based on 2.5 ppm residual of product (42.5 ug/L ac tive ingredient))

Acute COCs A Number of Days per Year of Exceedance of COCs No Treatment (0% Removal) 71% Removal During WWT 92% Removal During WWT High-end Average High-end Average High-end Average 123 ppb (Non-listed aquatic vascular plants) 0 0 0 0 0 0
60 ppb (acute freshwater fish 1 0 0 0 0 0
25.5 ppb (acute freshwater invertebrates, crustaceans) A 2 0 0 0 0 0

5.2 ppb (non-listed algae) 6 1 2 0 1 0

A Nonlisted freshwater mollusk, acute COC 9.5 ppb: Number of days were not computed for this taxa group, however, expect days of exceedance to be just under the number of days of exceedance as that for nonlisted algae. For example, for the High-end, No Tr eatment (0% removal), about 5 days is a rough estimate based on linear interpolation.Page 37 of 103 Table 10: Estimates of Numbers of Day P er Year of Exceedance of Endangered/Listed COCs for Freshwater Organisms Downstream of Moderate-Size Recirculating Cooling Towers (0.0029 kg/site/day release of ATMD be fore treatment based on 2.5 ppm residual of product (42.5 ug/L ac tive ingredient))

Endangered/Listed COCs A Number of Days per Year of Exceedance of COCs No WWT (0% Removal) 71% Removal During WWT 92% Removal During WWT High-end Average High-end Average High-end Average 20 ppb (Listed aquatic vascular plants) 2 0 1 0 0 0
6 ppb (acute listed freshwater fish 5 1 2 0 0 0
2.6 ppb (acute listed freshwater invertebrates, crustaceans) A 12 1 4 0 1 0

2.4 ppb (Listed algae) 12 1 4 0 1 0

A Listed freshwater mollusk, acute COC 0.95 ppb: Number of days were not computed for this taxa group, however, expect days of exceedance to be high er than the number of days of ex ceedance as that for listed algae.

Table 11: Estimates of Numbers of Day P er Year of Exceedance of Chronic COCs for Freshwater Organisms Downstream of Modera te-Size Recirculating Cooling Towers (0.0029 kg/site/day release of ATMD before treatment based on 2.5 ppm residual of product (42.5 ug/L ac tive ingredient))

Chronic COCs Number of Days per Year of Exceedance of COCs No WWT (0% Removal) 71% Removal During WWT 92% Removal During WWT High-end Average High-end Average High-end Average 16 ppb (Freshwater Invertebrate) 3 1 1 0 0 0
4 ppb (Freshwater fish) 8 1 3 0 1 0

Large-Size Recirculating Cooling Towers

Tables 12 through 14 present estimates of numb ers of days per year of exceedance of concentrations of concern (COCs) for fres hwater organisms downstream of large-size recirculating cooling towers. Table 12 presents estimates of the number of days per year of exceedance of acute COCs for freshwater organi sms, table 13 presents estimates of the number of days per year of exceedance of COCs for en dangered/listed freshwater organisms, and table 14 presents estimates of the number of days per year of exceedance of chronic COCs for
freshwater fish and invertebrates.Page 38 of 103 Table 12: Estimates of Numbers of Day Per Year of Exceedance of Acute COCs for Freshwater Organisms Downstream of Large- Size Recirculating Cooling Towers (0.0029 kg/site/day release of ATMD before treatmen t based on 2.5 ppm residual of product (42.5 ug/L active ingredient))

Acute COCs A Number of Days per Year of Exceedance of COCs No Treatment (0% Removal) 71% Removal During WWT 92% Removal During WWT High-end Average High-end Average High-end Average 123 ppb (Non-listed aquatic vascular plants) 12 1 4 0 1 0
60 ppb (acute freshwater fish 25 3 8 1 3 0 25.5 ppb (acute freshwater invertebrates, crustaceans) A 55 6 18 2 5 1

5.2 ppb (non-listed algae) 155 17 73 7 24 2

A Nonlisted freshwater mollusk, acute COC 9.5 ppb: Number of days were not computed for this taxa group, however, expect days of exceedance to be under the numbe r of days of exceedance as that for nonlisted algae. For example, for the High-end, No Treat ment (0% removal), about 134 days is a rough estimate based on linear interpolation.

Table 13: Estimates of Numbers of Day P er Year of Exceedance of Endangered/Listed COCs for Freshwater Organisms Downstream of Large-Size Recirculating Cooling Towers (0.0029 kg/site/day release of ATMD before treatment based on 2.5 ppm residual of product (42.5 ug/L ac tive ingredient))

Endangered/Listed COCs A Number of Days per Year of Exceedance of COCs No WWT (0% Removal) 71% Removal During WWT 92% Removal During WWT High-end Average High-end Average High-end Average 20 ppb (Listed aquatic vascular plants) 67 7 22 2 7 1
6 ppb (acute listed freshwater fish 144 15 66 7 21 2
2.6 ppb (acute listed freshwater invertebrates, crustaceans) A 215 26 116 12 46 5

2.4 ppb (Listed algae) 220 26 121 13 49 5

A Listed freshwater mollusk, acute COC 0.95 ppb: Number of days were not computed for this taxa group, however, expect days of exceedance to be gr eater than the number of days of ex ceedance as that for listed algae.Page 39 of 103 Table 14: Estimates of Numbers of Day P er Year of Exceedance of Chronic COCs for Freshwater Organisms Downstream of Large- Size Recirculating Cooling Towers (0.0029 kg/site/day release of ATMD before treatmen t based on 2.5 ppm residual of product (42.5 ug/L active ingredient))

Chronic COCs Number of Days per Year of Exceedance of COCs No WWT (0% Removal) 71% Removal During WWT 92% Removal During WWT High-end Average High-end Average High-end Average 16 ppb (Freshwater Invertebrate) 79 8 28 3 8 1
4 ppb (Freshwater fish ) 177 20 88 9 31 3

Once-through cooling systems

Tables 15 through 18 present estimates of nu mbers of days per year of exceedance of concentrations of concern (COC s) for freshwater organisms dow nstream of once-through cooling systems. Estimates presented fo r once-through cooling systems are fo r four different intake flow values: 2 MGD, 20 MGD, 50 MGD, and 100 MGD. The estimated number of days per year of
exceedance of concentrations of concern increase as the inta ke flow increases

Table 15: Estimates of Numbers of D ays of Exceedance of COCs for Freshwater Organisms Downstream of Once-through cooling systems with an Intake Flow of 2 Million Gallons per Day (MGD) Assuming No Trea tment and 2.5 ppm Residual of Product (42.5 ug/L active ingredient, ATMD)
High-end Estimate of Number of Days per Year of Exceedance of COCs Average Case Estimate of Number of Days per Year of Exceedance of COCs Acute COCs 123 ppb (Non-listed freshwater vascular plants) 2 3
60 ppb (Freshwater fish) 52 5 25.5 ppb (Freshwater invertebrates, crustaceans) A 97 10
5.2 ppb (algae) 219 26 Endangered/Listed COCs 20 ppb (freshwater vascular plants) 112 12 6 ppb (freshwater fish) 206 24 2.6 ppb (freshwater invertebrates, crustaceans) B 276 38
2.4 ppb (algae) 280 39 Chronic COCs 16 ppb (Freshwater Invertebrate) 127 13Page 40 of 103 High-end Estimate of Number of Days per Year of Exceedance of COCs Average Case Estimate of Number of Days per Year of Exceedance of COCs 4 ppb (Freshwater Fish) 240 30

A Nonlisted freshwater mollusk, acute COC 9.5 ppb: Number of days were not computed for this taxa group, however, expect days of exceedance to be just under the number of days of exceedance as that for nonlisted algae. Based on linear interpolation estimates of number of days of exceedance are 193 and 22 days, for the High-end and average case, respectively.

B Listed freshwater mollusk, acute COC 0.95 ppb: Number of days were not computed for this taxa group, however, expect days of exceedance to be gr eater than the number of days of ex ceedance as that for listed algae.

Table 16: Estimates of Numbers of D ays of Exceedance of COCs for Freshwater Organisms Downstream of Once-through coo ling systems with an Intake Flow of 20 Million Gallons per Day (MGD) Assuming No Treatment and 2.5 ppm Residual of Product (42.5 ug/L active ingredient, ATMD)
High-end Estimate of Number of Days per Year of Exceedance of COCs Average Case Estimate of Number of Days per Year of Exceedance of COCs Acute COCs 123 ppb (Non-listed freshwater vascular plants) 148 16
60 ppb (Freshwater fish) 207 24 25.5 ppb (Freshwater invertebrates, crustaceans) A 276 38
5.2 ppb (algae) 348 81 Endangered/Listed COCs 20 ppb (freshwater vascular plants) 293 43 6 ppb (freshwater fish) 345 76 2.6 ppb (freshwater invertebrates, crustaceans) B 357 111
2.4 ppb (algae) 357 114 Chronic COCs 16 ppb (Freshwater Invertebrate) 307 48 4 ppb (Freshwater Fish) 352 91

A Nonlisted freshwater mollusk, acute COC 9.5 ppb: Number of days were not computed for this taxa group, however, expect days of exceedance to be just under the number of days of exceedance as that for nonlisted algae. Based on linear interpolation estimates of number of days of exceedance are 333 and 72 days, for the High-end and average case, respectively.

B Listed freshwater mollusk, acute COC 0.95 ppb: Number of days were not computed for this taxa group, however, expect days of exceedance to be gr eater than the number of days of ex ceedance as that for listed algae.Page 41 of 103 Table 17: Estimates of Numbers of D ays of Exceedance of COCs for Freshwater Organisms Downstream of Once-through coo ling systems with an Intake Flow of 50 Million Gallons per Day (MGD) Assuming No Treatment and 2.5 ppm Residual of Product (42.5 ug/L active ingredient, ATMD)
High-end Estimate of Number of Days per Year of Exceedance of COCs Average Case Estimate of Number of Days per Year of Exceedance of COCs Acute COCs 123 ppb (Non-listed freshwater vascular plants) 224 27
60 ppb (Freshwater fish) 281 40 25.5 ppb (Freshwater invertebrates, crustaceans) A 329 59
5.2 ppb (algae) 358 122 Endangered/Listed COCs 20 ppb (freshwater vascular plants) 338 66 6 ppb (freshwater fish) 357 114 2.6 ppb (freshwater invertebrates, crustaceans) B 360 161
2.4 ppb (algae) 360 165 Chronic COCs 16 ppb (Freshwater Invertebrate) 344 73 4 ppb (Freshwater Fish) 359 136

A Nonlisted freshwater mollusk, acute COC 9.5 ppb: Number of days were not computed for this taxa group, however, expect days of exceedance to be just under the number of days of exceedance as that for nonlisted algae. Based on linear interpolation estimates of number of days of exceedance are 352 and 109 days, for the High-end and average case, respectively.

B Listed freshwater mollusk, acute COC 0.95 ppb: Number of days were not computed for this taxa group, however, expect days of exceedance to be gr eater than the number of days of exceedance as that for listed algae.

Table 18: Estimates of Numbers of D ays of Exceedance of COCs for Freshwater Organisms Downstream of Once-through coo ling systems with an Intake Flow of 100 Million Gallons per Day (MGD) Assuming No Treatment and 2.5 ppm Residual of Product (42.5 ug/L active ingredient, ATMD)
High-end Estimate of Number of Days per Year of Exceedance of COCs Average Case Estimate of Number of Days per Year of Exceedance of COCs Acute COCs 123 ppb (Non-listed freshwater vascular plants) 279 39
60 ppb (Freshwater fish) 322 55 25.5 ppb (Freshwater invertebrates, crustaceans) A 349 82
5.2 ppb (algae) 360 160 Endangered/Listed COCs 20 ppb (freshwater vascular plants) 352 91Page 42 of 103 High-end Estimate of Number of Days per Year of Exceedance of COCs Average Case Estimate of Number of Days per Year of Exceedance of COCs 6 ppb (freshwater fish) 359 152 2.6 ppb (freshwater invertebrates, crustaceans) B 360 200
2.4 ppb (algae) 360 204 Chronic COCs 16 ppb (Freshwater Invertebrate) 355 101 4 ppb (Freshwater Fish) 360 175

A Nonlisted freshwater mollusk, acute COC 9.5 ppb: Number of days were not computed for this taxa group, however, expect days of exceedance to be just under the number of days of exceedance as that for nonlisted algae. Based on linear interpolation estimates of number of days of exceedance are 358 and 143 days, for the High-end and average case, respectively.

B Listed freshwater mollusk, acute COC 0.95 ppb: Number of days were not computed for this taxa group, however, expect days of exceedance to be gr eater than the number of days of ex ceedance as that for listed algae.

4.3.2 Estimation of Risks to Freshwater Benthic Invertebrates Exposed to ATMD in
Sediments

Acute and chronic RQs and presumption of risk based on comparison to LOC values are discussed in Appendix D. Based on the fr eshwater high-end exposure scenario (10 th percentile 7Q10 distribution and associated concentrations of ATMD in sediments estimated from data on potential leaching adsorption-deso rption of ATMD to soil, RQs for listed and nonlisted benthic organisms exceed the LOC for subchronic risk for once-through and large-size recirculating cooling towers with no treatment (Tab le 19). Based on average exposure (50 th percentile), the LOC is not exceeded for any cooling tower scenar io. However, because there is no freshwater amphipod toxicity endpoint currently available, additional exceedances might occur for both exposure scenarios if the amphipod is a more se nsitive species than the midge. The approach
used to estimate sediment con centrations presented in Table 19 is discussed in Appendix E.

Table 19: Risk Quotients for Freshwat er Benthic Organisms Based on Estimated Concentrations of ATMD in Sediment (s ediment concentrations for 10th and 50th percentile 7Q10 Distribution)

Cooling System Scenario 10 th percentile 50 th percentile
Sediment Concentration

(mg ai/kgsediment) RQ 1 Sediment Concentration

(mg ai/kgsediment) RQ 1

Freshwater:
Once-Through Cooling System (2 MGD) with No Treatment 1053.8 5.6* 10.54 0.06Page 43 of 103 Cooling System Scenario 10 th percentile 50 th percentile
Sediment Concentration

(mg ai/kgsediment) RQ 1 Sediment Concentration

(mg ai/kgsediment) RQ 1

Large-Size Recirculating Cooling Tower (144 MGD) withNo Treatment484 2.6* 4.76 0.02

Large-Size Recirculating Cooling Tower with 71 Percent Removal During Wastewater Treatment 143.2 0.76 1.44 <0.01

Large-Size Recirculating Cooling Tower with 92 Percent Removal During Wastewater Treatment 39.5 0.21 0.41 <0.01

Moderate-Size Recirculating Cooling Tower (2.88 MGD) with No Treatment 9.52 0.05 .095 <0.01

Moderate-Size Recirculating Cooling Tower with 71 Percent Removal During Wastewater Treatment 2.77 0.01 .028 <0.01

Moderate-Size Recirculating Cooling Tower with 92 Percent Removal During Wastewater Treatment 0.78 <0.01 .0078 <0.01

1 RQ = sediment concentration/toxicity, where freshwater midge EC50 = 188 mg ai/kg sediment * exceeds the LOC for risk to benthic organisms

4.3.3 Estimation of Risks to Estuarine/Marine Organisms Exposed to ATMD in the
Water Column

Acute RQs comparing the concentration of AT MD at the discharge source (i.e., end of pipe concentration of 42.5 ug/L ATMD) to the av ailable toxicity endpoints exceed the acute LOCs for listed fish, listed and non-listed invertebrate s, and non-listed alg ae (Table 20). The most acutely sensitive estuarine invertebrates are mollusks as represented by tests with the Quahog clam ( Mercenaria mercenaria ), with an EC50 = 19 μg ai/L. Acute testing with another invertebrate, a crustacean—the mysid shrimp, Mysidopsis bahia (LC50 = 61 μg ai/L ) —was also
available but was not as sensitive as mollusks. On e acute toxicity value is available for estuarine fish, the Atlantic silverside ( Menidia menidia ; LC50 = 155 μg ai/L), and toxicity data also are
available for Skeletonema costatum (EC50 = 11 μg ai/L), a marine diatom. Chronic NOAECs
for fish and invertebrates were extr apolated from ACRs (see Table 7).Page 44 of 103 The concentrations of concern for listed a nd nonlisted species can then be calculated for each receptor group to determine the dilution factor s that are needed to minimize these risks.
Dilution factors of 4 to 5.5X would be sufficient to minimize risks to aquatic plants, listed fish, and nonlisted aquatic inve rtebrates. A dilution factor of 45X would be needed to minimize potential risks to listed estuarine mollusk invert ebrates whereas a factor of 2 is sufficient for

crustaceans.

Table 20: Concentrations of Concern for Risk to Water Column-Dwelling Estuarine/Marine Organisms and Dilution Factors That Would Minimize Risks

Receptor group RQ Federal status Concentration of concern (μg ai/L) Dilution factor needed to minimize risk

Acute:

Fish 0.27* Listed spp. 7.8 5.5 Nonlisted spp. 77.5 0 Invertebrates – Mollusks 2.23** Listed spp. 0.95 45 Nonlisted spp. 9.5 4.5 Chronic: Fish 8.3*** Listed and Nonlisted spp. 5.1 8-8.5 Invertebrates 2.2*** 19 2-3 Plants: Algae 3.8 # Nonlisted 1 11 4
Vascular plants 0.3 Nonlisted spp. 123 0
2 ## Listed spp. 42.5 2 * Exceeds the acute LOC for listed species (acute RQ > 0.05) **Exceeds the acute LOCs for listed (acute RQ >0.05) and nonlisted (acute RQ > 0.5) species ***Exceeds the chronic LOC (chronic RQ> 1)

# Exceeds the LOC for non-listed aqua tic plants (non-listed RQ > 1)

## Exceeds the LOC for listed aquatic plants (listed RQ > 1)

1 no algal species are currently listed

4.3.4 Estimation of Risks to Estuarine/Marine Benthic Invertebrates Exposed to
ATMD in Sediments

The risk quotient for estuarine benthic orga nisms is determined by comparing the worst case sediment exposure estimate (1445.7 mg ai /kg sediment) to the available toxicity data for the estuarine/marine amphipod (10-day EC 50 = 303 mg ai/kg sediment). The RQ = 4.77, which
exceeds the LOC for risk to es tuarine benthic organisms.Page 45 of 103 4.3.5 Estimation of Risks to Piscivorous Birds and Mammals

Piscivorous birds (e.g., herons , gulls, osprey) and mammals (e.g., otter, mink) are likely
to feed on fish and invertebrates that have been exposed to ATMD in th e water column. ATMD has some potential to bioconcentrate in fish (BCF = 378-388X, whole fish). An upper bound exposure based on an end-of-pip e discharge concentration of 42.5 μg ai/L (0.0425 mg ai/L) or less would result in low tissue levels, and the exte nt of bioconcentration will be mitigated by the strong tendency of ATMD to bind to suspended se diments. For birds, the greatest mitigating factor is that ATMD is only sligh tly toxic to practically nontoxic when administered in their diet (LC50s > 5000 ppm, 8 studies). Other mitigating factors such as proportion of population exposed on the day of release, proportion of diet these organisms would constitute, growth dilution, sediment burial, etc. all make it unlikely to resu lt in any detectable residues of concern. While there are no acute or repr oduction data for mammals, to a ssess human health hazards a 90- d NOAEL of 0.4 mg/kg-bw/day value from an or al gavage study using laboratory rats was
selected in lieu of acute and chronic data. Like with birds, at the upper bound end-of-pipe
concentration effects to mammals are not consid ered likely given all the mitigating factors.



### 4.4 Ecological Risk Characterization

To characterize the potential exposures and risks from this proposed new use of ATMD, it is important to consider limitations and uncerta inties for the following key aspects of this risk

assessment:

 EPA’s modeling of ecological exposures and risks;

 Uncertainties resulting from ecotoxicity data gaps;

 Uncertainties resulting from environmental fate data gaps;

 Mexel’s modeling of ecologica l exposures and risks; and

 Whole Effluent toxicity testing submitted by Mexel.

Evaluation of EPA’s Ecological Exposure and Risk Assessment Modeling Results

When interpreting the results of EPA’s hum an and ecological risk assessment, it is important to note that sorption of ATMD to suspended solids in the water column was not quantitatively considered. By extrapolation from laboratory st udies on adsorption/desorption of ATMD in soils, ATMD would be expected to have a very high potential to sorb to suspended
sediments in the water column. Since EPA’s E-FAST model was unable to account for the phenomenon of sorption of ATMD to suspended se diments in the water column, this would leadPage 46 of 103 to overestimates of surface water concentrations predicted downstream of facilities where ATMD would be expected to be used.

EPA ecological modeling results are based on loadings that would estimate surface water concentrations for peak exposures. EPA’s models require input in units of kilograms ATMD per site per day to estimate surface water concentr ations downstream of f acilities that use ATMD. According to use instructions on the label, the daily dose of MEXEL 432/0 is 4.0 ppm for 30
minutes with a residual concentr ation of 2.5 ppm. (The residual concentration of ATMD at 1.7% in product would be 42.4 ug/L.) Th e label also states that normal frequency of treatment is once per day or as needed to maintain control. Since the label contained no upper limit on the frequency of treatment on a daily basis, loadings of ATMD in kg/site/day EPA used in modeling assumed that a 2.5 ppm residual product (42.5 ug /L ATMD) would be maintained continuously over a 24-hour period. This assumption serves tw o purposes: (1) It provides estimates of peak exposures that are needed to estimates acute ri sks to aquatic organisms and (2) it provides a worst case exposure estimate base d on the lack of an upper limit of application frequency on the product label.

If the maximum application of MEXEL 432/0 is limited to a single dose applied daily for 30 minutes, peak daily hourly and chronic peak risk estimates used to assess exposures to aquatic organisms would be reduced. Ba sed on guidelines for Whole Efflue nt Toxicity tests, for acute criteria, EPA recommends an averaging period of 1 hour and for chronic criteria an averaging period of 4 days. Based on these guidelines, daily loadings that EPA used in its modeling for calculating acute exposures would decrease by a factor of 2 and fo r chronic exposures by a factor
of 48.

EPA’s E-FAST modeling results are based on th e ratio of distributions of plant flows to
stream flows for facilities in th e Standard Industrial Classificati on (SIC) code for Steam Electric Power Plants (4911). There are instances in which stream flow and/or pl ant flow data may be missing for a facility. In instances in which the plant effluent flow is greater than the stream flow, E-FAST assumes that the effluent flow is equal to the stream flow; in cases where the stream flow is greater than the plant effluent flow, the stream fl ow is equal to the sum of the stream flow and plant effluent flow. Consequently, it is possibl e that unrealistic plant flow to stream flow ratios can occur that would depict conditions that would not be likely to be found under real-world conditions; this would be expe cted to introduce un certainties that would generally tend to lead to overest imates of exposures and risks.

Due to the somewhat static nature of estuarine/marine water bodies relative to flowing freshwater bodies, potential expo sure and risks to aquatic organi sms in estuarine/marine water bodies may be higher than those to aquatic or ganisms in freshwater bodies. Suspended solids content of estuarine/marine systems, however, might generally be expected to be higher than that for freshwater systems leading to greater poten tial for sorption of ATMD, which could reducePage 47 of 103 potential exposures to organisms in the wate r column, but increase exposures to sedimentdwelling organisms.

Uncertainties Resulting from Gaps in Ecotoxicity Data

There are several uncertainties associated with ga ps in the ecotoxicity pr ofile. For freshwater benthic organisms, data are available only for the midge. Lack of data for an amphipod might results in risk being underestimated if the amphi pod is more sensitive than the midge. In the
absence of data for fish and estuarine/marine invertebrates, Acute-Chronic Ratios (ACRs) were used to extrapolate NOAECs. Some uncertainty ex ists in extrapolating from freshwater species to estuarine/marine species, because the chronic mode of action may differ. An Interspecies Correlation Estimation (ICE) model also was used to extrapolate an LC50 for the fathead minnow and an EC50 for cyanobacteria. Addi tionally, all availabl e acute and chronic ecotoxicity data are based on continuous exposure (e. g., 96-h fish LC50, 21-day invertebrate life cycle). However, if MEXEL 432/0 is applie d for a maximum of only 30 minutes per day, exposure would be intermittent rather than continuous. Although the Agency has not reviewed the data, summary toxicity endpo int values presented for freshw ater fish and daphnids in a mixing zone evaluation for a nucl ear plant indicate that interm ittent exposure of 20 minutes per day results in lower toxicity to aquatic or ganisms than do the endpoints from continuous exposure. If toxicity is less from intermittent exposure, then the LOC exceedances might be
reduced over those calculated for MEXEL 432/0. La stly, ecotoxicity data are not available for the product, which is only 1.7% ai. Any toxicity due to the inert ingredients would be in addition to that of the TGAI and might result in an unde restimation of acute a nd chronic toxicity to aquatic organisms.

Uncertainties Resulting from Gaps in Environmental Fate Data

The registrant has not submitted guideline a quatic metabolism studies for ATMD. These studies would provide information on the formation and decline of potential degradates. Aerobic aquatic metabolism data (835.4300) represent the water column in a wa ter body while anaerobic aquatic metabolism data (835.4400) represent benthi c and suspended sediments. In lieu of aquatic metabolism guideline studies , the registrant provided litera ture studies to address the persistence of alkyl amines a nd degradates in sediment and water. The literature studies 7 demonstrated that degradation of alkylamine s occurs, but none of these studies provided estimates of half-life of alkylamines or their me tabolic intermediates in the aquatic environment,

7 Cerniglia and Perry (1975), Nguyen et al. (2008), and van Ginkel et al. (2008)Page 48 of 103 and therefore their persistence of ATMD in the aquatic environment cannot be estimated at this time (MRIDs 49208802, 49208803). As a result, the Agency assumed stability of ATMD in the aquatic environment since no aerobic and anaerobic aquatic metabolism studies were submitted that would provide information on the potential rate of formati on and decline of degradates. Data on aerobic and anaerobic aquatic metabolism of ATMD would allow the Agency to develop a more refined estimate of potential exposur es and risks to ecological organisms.

Evaluation of Modeling Results Provided by Mexel

In a non-guideline study submitted to the Agen cy (Ackerman, D, F Ghillebaert, and MW Glass, 2013: MRID 49040220), Mexel used two modeling approaches to estimate exposures and risks to aquatic organisms downstream of two po wer plants. The first modeling approach used the site-specific option of the General Popul ation and Ecological Exposure from Industrial Releases module of E-FAST to provide screen ing level estimates of exposures to aquatic organisms. The second approach used the hi gher tier CE-QUAL-W2 model to provide more refined estimates of exposures to aquatic organisms. This higher tier model demonstrated
reduction in concentrations of ATMD with dist ance downstream of the facilities modeled and considered influences of stream bathymetry characteristics on surface water concentrations. Mexel considered the two power plants they select ed for modeling to be atypical and to have the greatest impact. One power plan t, the Hammond Power Plant near Rome, Georgia was selected to be representative of the distribution of fac ilities in Standard Industr ial Classification Code (SIC) 4911 (i.e., steam electric power plants); Mexel reports that this power plant was in the 95 th percentile of all power plant discharges and that its discharge flow of 2082 million liters per day (MLD) was approximately equal to the 7Q10 flow of the Coosa River downstream of the plant (i.e., 2927 MLD), representing a realistic case wher e the dilutive capacity of the receiving water would be at a minimum. The second power plant, the Crockett Power Plant near Girvin, TX was selected by Mexel to investigate the impacts of using ATMD at a smaller power plant on a smaller stream, the Pecos River; Mexel reports th at the discharge flow from this power plant,
5.29 MLD was in the 37 th percentile of the distribution of po wer plants and that the 7Q10 flow of
the Pecos river downstream of the plant is 5.24 MLD (mean stream flow is 1674 MLD).

In estimating loadings used as inputs for modeling, Mexel assumed that the product, MEXEL 432/0, would be applied over a 30- minute period to achieve a maintenance concentration of ATMD of 42.5 ug/L. Mexel estimated that this concentration would result in 1.04 kg/day of ATMD being released to surf ace water from the Hammond Power Plant and 0.00468 kg/day of ATMD being released to surface water from the Crockett Power Plant. These daily loading estimates that Mexel used as inpu ts to the Industrial Rele ases module of E-FAST were derived by averaging a single loading of 30 minutes duration over a 24-hour period; these loadings were further reduced to reflect a 44 percent “immediate demand” that wasPage 49 of 103 representative of the range of “immediate demand s” from 21 to 86% for the formulated end use product (EP). This “immediate demand” is applied to account for removal as a result of adsorption of ATMD to suspended sediments in the water column. Av eraging the amount of ATMD applied during a 30-minute period over a 24-hour period and further reducing loadings by applying a factor for “immediate demand” te nd to underestimate poten tial acute exposure to aquatic organisms, but might be appropriate fo r estimating potential ch ronic risks to aquatic organisms.

According to the proposed product label, “Nor mal frequency of treatment is once per day
or as needed to maintain cont rol. The amount of the daily dos e is determined by the circuit characteristics. The daily dose is 4.0 ppm for 30 minutes with a residu al concentration of 2.5 ppm.” As noted earlier, the maintenance c oncentration of 2.5 ppm corresponds to 42.5 ug/L ATMD. Since the label does not specify an uppe r limit on the number of a pplications of product per day and specifies maintenance of a residual concentration of 2.5 ppm product, EPA estimates that as a worst case up to 88.5 kg/day of ATMD could be released to surface water from the Hammond Power Plant as compared to Mexel’s assumption of 1.04 kg/day.

In selecting facilities as candidates for m odeling using E-FAST, Mexel eliminated from further consideration 878 of 1277 power plants in the E-FAST database of facilities in SIC 4911 (Steam Electric Power Plants). Power plants eliminated included those reported to have no discharge and those with 7Q10 flow s reported to be 0 MLD. In addition, Mexel also eliminated streams that had low flows (7Q10) less than the plant discharge flows, leaving 399 facilities as candidates for site-specific modeling.

Although Mexel provided information on where the two facilities they modeled lie along the distribution of plant flows for the 399 of 1277 facilities selected as potential candidates for modeling, it is not clear where th ese facilities would li e with regard to potential exposure and
risk for all 1277 facilities within SIC code 4911. Results on days per year of exceedance for the two facilities modeled are general (presented in graphs) with no results provided for specific
COCs.

Although the two facilities modeled by Mexe l might provide conservative estimates of exposure relative to other facil ities where ATMD could be used, EPA cannot conclude based on modeling results provided by the re gistrant from 2 of 1277 facilitie s in the Steam Electric Power
Plants SIC code that that the use of ATMD at these types of facilities will not pose potential concerns for exposure and risk to aquatic orga nisms for all facilities on flowing water bodies where the proposed new use of this chemical may occur. , Additionally, these modeling results would not be representative of facilitie s located on estuarine/marine water bodies.Page 50 of 103 Evaluation of WET Results Submitted by Mexel

Whole effluent toxicity testing from two facilities, Calvert Cliffs Nuclear Power Plant (CCNPP) and Donald C. Cook Nuclear Power Pl ant (DCCNPP) conducting efficacy trials with Mexel were submitted by the registrant (MRID 49208816); details of these studies are provided in Appendix E. CCNPP is located along an estuar ine area of the Potomac River and DCCNPP is located along the shore of Lake Michigan. Both facilities have once th rough cooling systems. The design flow is 3460 million gallons per day at CCNPP and 2405 million gallons per day at
CCNPP. The studies show that under certain dosing regimes and mi xing zones there are
facilities that would be able to use Mexel in once through cooling systems without resulting in unreasonable adverse effects to the aquatic environment. For facilities that ne ed to meet limits at the end-of-pipe, however, the pr oposed label rate would result in exceedances for once-through systems.

Chronic short-term whole effluent toxicity testing was conducted at CCNPP with both an estuarine fish and shrimp species. The 7- day NOAECs were 50%, 100% and 100% for Inland silverside and 100% and 100% for mysids. While the studies as presented in the drafts appear to be scientifically sound studies for the specific f acility and its treatment regime, critical primary study design information was missing from the package provided which would allow the study results to bridge to use in othe r cooling water systems, and the highest allowed label application regime. Specifically, unknown timing between dosi ng of cooling water system and collection of effluent, the lack of dosing the cooling water sy stem with Mexel on all effluent collection days
which is assumed to mean no ATMD would be present in effluent, and the lack of dosing information for some dates (e.g., all of June, July) during the effluent collection period. Additionally, no analytical meas urements were made on ATMD levels present in the 100% effluent. While such analytical information wa s not necessary for the purpose of the study, to bridge to other water cooling syst ems such information is critical.

Acute whole effluent testing with a freshwa ter fish and cladoceran were conducted at DCCNPP. Three types of effluent samp les were tested for each species:

 A 24-h composite effluent sample where grab samples occurred hourly and where Mexel was applied for 30 minutes dur ing one of these hours;

 An effluent grab sample from the 30 minute Mexel dosing period in the previous bullet; and Lake water dosed with Mexel from a pilot test ri g mixed with two gallons of untreated lake water
to simulate a 3:1 dilution.

The 24-h composite 48-h LC 50 for D. magna and the 96-h LC 50 for the fathead minnow were both greater than the concentration found in 100% effluent. The single grab sample had a
fathead minnow 96-hour LC 50 of 27.7% effluent and the D. magna a 48-h LC 50 of 35.4% effluent. Based on these results a mixing zone with a dilution of 3:1 was postulated as being ablePage 51 of 103 to meet a Tier I acute ambient water quality criterion of 0.1 ppm Mexel, developed for the facility. However, the one 3:1 dilution test fr om the pilot test rig study still showed acute mortality occurring (LC 50 = 66% effluent for both species).



### 4.7 Section 4 References

Ackerman, D, F Ghillebaert, and MW Glass. 2013. Duomeen C Water Concentration Modeling for Cooling Towers and Once-Through Industria l Cooling Water Systems. Non-guideline study.
MRID 49040220.

EPA. 2013. Web-based Interspecies Correla tion Estimation (Web-ICE) for Acute Toxicity: User Manual (version 3.2). EP A/600/R-12/603. USEPA Office of Research and Development, Gulf Ecology Division, Gulf Breeze, FL http://www.epa.gov/ceampubl/fchain/webice/

EPA. 2010. Predicting the Toxic ities of Chemicals to Aquatic Animal Species. USEPA Office of Water and Office of Pesticide Programs, Washington, DC; Office of Research and Development, Gulf Ecology Division; and Office of Research and Development, Mid-Continent Ecology Division. October 27, 2010.Page 52 of 103 

### 5.0 SUMMARY OF POTENTIAL HUMAN AND ECOLOGICAL RISKS

This document presents the United States Environmental Protection Agency’s human and ecological risk assessment for the new use of the active ingredient, N-coco 1,3-diaminopropane (also sometimes referred to as N-(coco alkyl)tri methylenendiamine, Duomeen C, and ATMD) in
MEXEL 432/0 to control biofou ling in once-through and recircul ating cooling towers. The active ingredient in MEXEL 432/0 is gene rally hereinafter re ferred to as ATMD (alkyltrimethylenediamine).

MEXEL 432/0 is to be used for the cont rol of biofouling, including zebra mussels and clams in once-through cooling and cooling tower circu its with closed de livery systems for nonpotable industrial freshwater a nd sea water systems. The produc t may be applied to maintain clean systems or to treat systems that are alread y fouled. Normal frequency of treatment is once per day or as needed to maintain control. The amount of the daily dose is determined by the circuit characteristics. The daily dose is 4.0 ppm for 30 minutes with a re sidual concentration of 2.5 ppm.

According to the product labe l, the concentration of ac tive ingredient, ATMD, is 1.7 percent. Based on maintenance of 2.5 ppm pr oduct residual, this corresponds to 42.5 ug/L
ATMD.

ATMD would not be expected to be more toxi c than alternative chemical substances that could be used as cooling tower biofoulants. Si nce facilities that would be expected to use ATMD have NPDES permits, there woul d be no increased regulatory burden.

The exposure scenarios that form the basis of EPA’s risk assessment include releases to
surface water from:

 large-size recirculating cooling towers;

 moderate-size recirculati ng cooling towers; and

 once-through coo ling systems.

For recirculating cooling towers, exposures fr om releases of ATMD to surface water were
estimated with and without wastewater treatme nt. For once-through cooling systems, it was
assumed that no treatment of effluent occu rs prior to discharge to surface water.

This risk assessment considers risks to bot h humans and ecological organisms. Risks to
humans evaluated in this assessm ent include potential dietary ri sks from ingestion of drinking water and potential risks from occupational ex posure during mixing and loading of ATMD. Estimates of potential dietary risk s to humans from ingestion of drinking water were determined to be negligible based on worst case estimates of drinking water concen trations and published information on drinking water consumption by humans at a high level of consumption.Page 53 of 103 Although potential risks were identified for occu pational dermal and inhalation exposure during mixing and loading, these risks can be minimized if the label specifies that the proposed product be applied using closed loading and delivery systems. (The labe l currently only specifies “closed delivery systems”.)

The ecological risk assessment for AT MD considers three key components:

 EPA’s assessment of risks to ecological organisms from exposure to ATMD;

 Whole Effluent Toxicity (WET) test data on submitted by the registrant; and

 Site-Specific modeling submitted by the registrant.

When interpreting the results of EPA’s hum an and ecological risk assessment, it is important to note that sorption of ATMD to suspended solids in the water column was not quantitatively considered. By extrapolation from laboratory st udies on adsorption/desorption of ATMD in soils, ATMD would be expected to have a very high potential to sorb to suspended
sediments in the water column. Since EPA’s E-FAST model was unable to account for the phenomenon of sorption of ATMD to suspended se diments in the water column, this would lead
to overestimates of surface wa ter concentrations predicted downstream of facilities where ATMD would be expected to be used.

EPA ecological modeling results are based on loadings that would estimate surface water concentrations for peak exposures. Two general quantitative approaches were used by EPA to assess risks to ecological organi sms: a risk quotient (RQ) me thod and a probabilistic method (These are discussed further in Appendix E). The probabilistic approach was used to estimate potential risks to freshwater fi sh and invertebrates. Both av erage case and high end scenarios were evaluated. For the high-end scenario, results of the number of days per year that COCs are exceeded is based on the upper 10 th percentile of the ratio of str eam flows to plant flows (Also referred to as Stream Dilution Factors (SDFs) . For the average case scenario, results of the number of days per year that COCs are exceeded are based on the 50 th percentile of SDFs. For the upper 10 th percentile SDFs, or high-e nd scenario, the stream flow to plant flow ratio is relatively low since plant flows can contribute considerable volume to the flow of the stream and resulting surface water concentrations can be relatively high. For the 50 th %ile SDF, the stream flow to plant flow ratio is more typical.

The risk quotient method was used to estim ate potential risks to freshwater benthic invertebrates, marine/estuarine freshwater fish and invertebrate s, and estuarine/marine benthic organisms. In addition, for marine /estuarine fish and invertebrates, dilution factors that would be needed to mitigate exceedance of concentrations of concern were estimated. In estimating
sediment concentrations of ATMD to which fr eshwater benthic organi sms would be exposed,
estimated surface water concentrations were mul tiplied by an average experimentally-determined adsorption/desorption value. In estimating sedime nt concentrations to which estuarine/marine organisms would be exposed, the effluent concen tration of ATMD at the end of pipe fromPage 54 of 103 information on the product label was multiplied by an average experimentally-determined adsorption/desorption value. A qualitative appro ach was used to estimate potential risks to piscivorus birds and mammals.

Releases of ATMD from recirculating c ooling towers to receiving water bodies and associated exposures are predicted to be mu ch lower than those from once-through cooling systems. First, releases from recirculating cooling towers are from blowdown water, which constitutes a fraction of the total cooling tower intake flow, whereas releases from once-through cooling systems consist of the total intake flow . (Blowdown is assumed to be only 0.06 percent of recirculating cooling tower in take flow.) Second, e ffluents from recirculating cooling towers may possibly undergo wastewater treatment wh ereas effluents from once-through cooling systems would not. .

Tables 9, 10 and 11 present estimates of nu mbers of days per year of exceedance of concentrations of concern (COCs) for freshw ater organisms downstream of moderate-size recirculating cooling towers based on releases of ATMD with and without wastewater treatment. Tables 12, 13, and 14 present estimates of numbers of days per year of exceedance of COCs for freshwater organisms downstream of large-size reci rculating cooling towers based on releases of
ATMD with and without wastew ater treatment. Tables 15 th rough 18 present estimates of numbers of days per year of exceedance of COCs for freshwater organisms downstream of oncethrough cooling systems at intake flow values of 2, 20, 50, and 100 million gallons per day (MGD), respectively. Exceedance of an acute COC and of an endangered/listed COC for one day or more indicates that there may be potential acute adverse eff ects to freshwater organisms. Exceedance of chronic COCs for 20 days or more indicates that there may be potential chronic adverse effects to freshwater organisms.

If the maximum application of MEXEL 432/0 is limited to a single dose applied daily for 30 minutes, peak daily hourly and chronic peak risk estimates used to assess exposures to aquatic organisms would be reduced. Ba sed on guidelines for Whole Efflue nt Toxicity tests, for acute criteria, EPA recommends an averaging period of 1 hour and for chronic criteria an averaging period of 4 days. Based on these guidelines, loadings that EPA used in its modeling for calculating acute exposures would decrease by a factor of 2 and fo r chronic exposures by a factor
of 48.

EPA used the risk quotient method to estim ate potential risks to freshwater benthic organisms. These results are presented in Tabl e 19. Based on sediment concentrations derived from the high-end scenario (10 th percentile of stream flow to plant flow dist ribution), the level of concern would be exceeded for large size recircul ating cooling towers with no treatment and for once-through cooling systems. Based on the average case scenario, there would be no
exceedances of levels of concern fo r freshwater benthic organisms.Page 55 of 103 EPA used the risk quotient method and e nd of pipe concentrations of ATMD to
determine worst case estimates of risks to estu arine/marine fish and invertebrates exposed to
ATMD in the water column and to estuarine/marine benthic invertebrates in sediments. Table 20 presents dilution factors that would be needed to reduce risks to below co ncentrations of concern for water-column dwelling estuarine/marine orga nisms. Based on a worst case estimate of the
concentration of ATMD in estuar ine/marine sediment, the level of concern for estuarine/marine benthic organisms would be exceeded.

Based on a qualitative evaluation, EPA determined that potential risks to piscivorus birds and mammals would be negligible.

In a non-guideline study submitted to the Ag ency (Ackerman, D, F Ghillebaert, and M.W. Glass, 2013: MRID 49040220), Mexel used two modeling approaches to estimate exposures and risks to aquatic organisms downstr eam of two power plants. The first modeling approach used the site-specifi c option of the General Populati on and Ecological Exposure from Industrial Releases module of E-FAST (i.e., Indu strial Releases module) to provide screening level estimates of exposures to aquatic organisms. The second approach used the higher tier CEQUAL-W2 model to provide more refined estimat es of exposures to aquatic organisms..

The daily loading estimates th at Mexel used as inputs to the Industrial Releases module of E-FAST were derived by av eraging a single loading of 30 minutes duration over a 24-hour period. These loadings were fu rther reduced to reflect a 44 pe rcent “immediate demand” that was representative of the range of “immediate demands” from 21 to 86% for the formulated end use product (EP). This “immediate demand” is applied to account for re moval as a result of adsorption of ATMD to suspended sediments in the water column. Av eraging the amount of ATMD applied during a 30-minute period over a 24-hour period and further reducing loadings by applying a factor for “immediate demand” te nd to underestimate poten tial acute exposure to aquatic organisms, but might be appropriate fo r estimating potential ch ronic risks to aquatic organisms. Results on days per year of exceed ance for the two facilitie s modeled are general (presented in graphs) with no re sults provided for specific COCs.

Although the two facilities modeled by Mexe l might provide conservative estimates of exposure relative to other facil ities where ATMD could be used, EPA cannot conclude based on these modeling results that the use of ATMD at these types of facilities will not pose potential concerns for exposure and risk to aquatic organi sms for all facilities wh ere the proposed new use of this chemical may occur. Additionally, thes e modeling results are not representative of
facilities located on estuar ine/marine water bodies.

Whole effluent toxicity testing from two facilities, Calvert Cliffs Nuclear Power Plant (CCNPP) and Donald C. Cook Nuclear Power Pl ant (DCCNPP) conducting efficacy trials with Mexel were submitted by the registrant (MRID 49208816); details of these studies are provided in Appendix E. Both facilities have once through cooling systems. The studies show that underPage 56 of 103 certain dosing regimes and mixing z ones there are facilities that w ould be able to use Mexel in once through cooling systems wit hout resulting in unreasonable a dverse effects to the aquatic
environment. For facilities that need to meet limits at the end-of-pip e, however, the proposed
label rate would result in exceed ances for once-through systems.

There are uncertainties associated with gaps in ecotoxicity data incl uding lack of data on a second species of benthic inve rtebrates, estimates from WEB-ICE and acut e to chronic ratio estimates. Some summary information appeared to indicate that interm ittent exposures would result in lower toxicity than continuous exposures, but the Agency did not have enough information to review. Also, ecotoxicity data were only available for th e active ingredient and no data were available on the formulated product; data for the TGAI, which comprises 1.7% of the product, may underestimate the toxicity of the formulation.

Further, there are uncertainti es associated with gaps in environmental fate data. The Agency assumed stability of ATMD in the aqua tic environment since no aerobic and anaerobic aquatic metabolism studies were submitted that w ould provide information on the potential rate of formation and decline of degradates. Data on aerobic and anaerobic aquatic metabolism of ATMD would allow the Agency to develop a mo re refined estimate of potential exposures and risks to ecological organisms.

Finally, although ATMD would be expected to have a very high pot ential to sorb to suspended sediments in the water column, EP A’s models were unable to account for this phenomenon. Therefore, estimated surface water concentrations do not quantitatively consider this removal process.

In summary, there are no pot ential risks for human health from the use of ATMD as a biofoulant in cooling towers if the proposed labe l is modified to require “closed loading and delivery systems”. There are also no risks of co ncern for piscivorus bird s from the cooling tower

use.

There are potential risks of concern to all aquatic organisms both freshwater and estuarine organisms from the use of ATMD as a biofoulant. These risk s are expected to be similar to risks from other antimicrobial pesticid es which are used as antifoulants. Risks are higher for once through towers than for recirculati ng towers and higher for large facilities than
for small or moderate size facili ties. Estimated acute and chroni c risks to aquatic organisms in
the water column would be lower and potentially eliminated in some instances if the proposed label is modified to limit application to a maxi mum of one 30-minute application per day and if the potential for sorption to suspended sediments is accounted for.Page 57 of 103 

### APPENDIX A: ENVIRONMENTAL FATE DATA

Introduction

ATMD is a mixed alkyl triethylene diamine surfactant (surface acting agent) with alkyl
chains that contain 8-18 carbons in even in crements. The predominant constituents (C 12 , C 14 , C 16 , and C 18 ) accounted for 45.3, 16.2, 9.5, and 11.1 % of the total mixture, respectively. Taken together, the four predominant constituents a ccount for 82.1 % of the parent mixture. The remaining diamine compounds (C 8 and C 10 ) account for a total of 9.3 % of the parent mixture (MRID 49040203).

The registrant submitted product chemistry studies for their product which contain information that appears to be useful for risk assessment. The UV Visible absorption spectrum study indicates that th e maximum sorption is in the rang e of 202-218 nanometers (nm) of wavelength, with only a small amount of abso rption in the 290-350 nm range (MRID 49040202). As a result of this limited UV sorption, minimal photodegradation by sunlight is expected. The weighted average 8 octanol-water partitioning coeffi cient (log P) of the N-coco-1,3- diaminopropane product was 0.2 (unitless ), but it ranged from -3 (for C 8 alkyl chain) to 2-2.5 (for C 18 alkyl chain) [MRID 49040203]. Based on this log P value, this mixed product can bioconcentrate but is not expe cted to have high bioconcentr ation in aquatic organisms. 9

, 10 The water solubility for the entire product is relativel y low because of the alkyl carbon chain, and is approximately 10 mg/l (ppm) (MRIDs 49040204, 48486702).

ATMD is used in non-potable water system s (once-through and recirculating) and some
residues will reach the environment from this us e. Once ATMD reaches the environment, the extent of dissipation by different routes will vary. Chemical degradation of ATMD (hydrolysis and photodegradation) is not expected to be significant ro ute of dissipation 11 . The extent of microbial degradation in the a quatic environment is uncertain because the registrant did not address the persistence of parent alkylamines (or suitable surrogates) in sediment and water and did not provide information on the persistence of the reduced-length chai n degradates of alkyl
amines 12 ) If the effluent from the treated water syst ems is released direct ly to surface water and not treated, it will reach surface water where it will sorb strongly to bottom and suspended sediment (~99 %) in as little as two hours. The K f (whole soil) sorption values were 14,454-

8 Weighted arithmetic mean of (log P for each compound * percentage in mixture) /91.4 % diamine content.

9 TG OECD 305 states that a compound having a log P of > 3 does not have “high” lipophilicity

10 http://www.epa.gov/scipoly/sap/meetings/2008/octobe r/305_bioconcentration_flowthrough_fish_test.pdf

11 MRIDs 40062413, 41069001, and 93034010 for hydrolysis and 49040202 and 49208801for photodegradation in

water
12 MRIDs 49208802, 49208803,Page 58 of 103 50,898 ml/g and K oc (sorption values onto organic car bon were 696,677-4,551,033 ml/g with 1/n
values of 0.48-0.82 13 . Some bioconcentration in fish will occur, based on bioconcentration factors (BCFs) of 82-180X (edi ble), 525-610X (non-edible), and 378-388X (whole fish). The 50 % depuration times were 17 days (edible), 8.5-21 days (non-edible), and 9.2-30 days (whole fish). 14 Bioconcentration in fish will be more likely in streams w ith limited amounts of suspended sediment to sorb any active ingredient that may reach water. However, in streams with a significant amount of suspended sediment , the extent of bioconcentration will be limited by the sorption to sediment (>99 %) by 2 hours 15 and in sludge (~83 %) by 4-6 hours. 16

In a WWTP, the primary route of dissipati on is expected to be sorption to activated sludge with some biodegradation. ATMD was st rongly sorbed to activated sludge with Kf values of 39,753 and Koc values of 105,222 L/kg by 24 hours. The extent of sorption increased with time based on 71-92 % sorption by 4-6 hour s (mean of 83 %) and 94-98 % sorption by 12- 24 hours (mean of 96 %) (MRID 49040205). ATMD was not readily biodegradable in an OECD 301D Closed Bottle test (MRID 49040207). At 2 mg/l of ATMD, the registrant reported that 69 % of the theoretical oxygen demand (T hOD) was reached by 28 days, and therefore ATMD should be considered to be readily biodegr adable. However, this result does not meet the pass criterion established for this guideline. The OECD 301D test guide line criterion for ready biodegradability in a Closed Bo ttle test is 60 % of ThOD in a 14-day period, and this 14-day period starts when 10 % of ThOD disappears and must end by before day 28 of the test. 17 In the study, 10 % ThOD disappearance occurred at appr oximately 8 days, and the maximum percent ThOD disappearance in any 14-da y window was 42 % (from 8-18 days). In the ASRI study there were inadequate sampling concentrations between 10 and 30 mg/l of test substance where nearly 80 % inhibition occurred with no concentr ation intervals in-between. The calculated IC 50 was 22 mg/l with a 95 % confidence interval of 10-30 mg/l. 18 A biodegradation simulation test, such as OCSPP 835.3240, 835.3280, or 835.3220, would be more appropriate as a measure of biodegradability during ac tivated sludge treatment than the ready biodegradability test (OCSPP 835.3110).

13 MRID 49040206

14 MRID 49040210

15 MRID 49040206

16 MRID 49040205

17 P. 3, OECD 301, http://www.oecd.org/chemicalsafe ty/risk-assessment/1948209.pdf

18 MRID 49040218Page 59 of 103 

### Product Chemistry

The registrant submitted product chemistr y studies for N-coco-1,3-diaminopropane
which considered in this risk assess ment to contain usable information. 19 These studies included the UV visible absorption spectrum (OCSPP 830.7050) 20 , octanol-water partition coefficient (Log P or Log Kow, OCSPP 830.7550) 21 , and water solubility (OCSPP 830.7840) 22

. The UV Visible absorption spectrum study indica tes that the maximum sorption is in the range of 202-218 nm of wavelength, but a small amount of absorption does occur from 290-350 nm (MRID 49040202). However, the small amo unt of absorption above 290 nm was not deemed to be significant to create pote ntial photodegradation in water (OCSPP 835.2240) 23 as a route of dissipation in the environment. 24

The Log P or Log Kow study (OCSPP 830.7550) st udy results are used to indicate the potential or lack of potential for bioconcentration in fish (OCSPP 850.1730) 25 and activated sludge sorption isotherm (OCSPP 835.1110). 26 The weighted average log P value of the Ncoco-1,3-diaminopropane product in MRID 49040203 was 0.2 (unitless) . However, the log P ranged from -3 (for C 8 alkyl chain) to 2-2.5 (for C 18 alkyl chain). Based on this log P value, this mixed product can bioconcentrate but is not expect ed to have high biocon centration in aquatic organisms. 27

, 28 The registrant submitted separate studies for bioconcentration in fish and activated sludge sorption isothe rm which are summarized below. 29

The water solubility study (OCSPP 830.7840) results are variable for N-coco-1,3- diaminopropane. Because N-coco-1,3-diaminopropane contains C 8 -C 18 alkyl chains, the chemical and physical properties will vary with the chain length. Accord ing to the registrant, 83.4 % of the formulation has high solubility (> 10 mg/l), 14.9 % has low solubility (<10 mg/l), and 1.7 % is insoluble. In addition, the formul ated product has dispersants and adjuvants which

19 MRIDs 49040202, 49040203, 49040204

20 OCSPP 830.7050, UV/Visible Absorption, http://www.regulations.gov/#! documentDetail;D=EPA-HQ-OPPT2009-0151-0024

21 OCSPP 830.7550, Partition Coefficient (n-Octanol/Water), Shake Flask Method, http://www.regulations.gov/#!documen tDetail;D=EPA-HQ-OPPT-2009-0151-0031

22 OCSPP 830.7840, Water Solubility: Column Elution Method; Shake Flask Method, http://www.regulations.gov/#!documen tDetail;D=EPA-HQ-OPPT-2009-0151-0034

23 OCSPP 835.2240, Photodegradation in water, EPA-HQ-OPPT-2009-0152-0012[1].pdf , http://www.regulations.gov/#!documen tDetail;D=EPA-HQ-OPPT-2009-0152-0012

24 Jennings, August 19, 2013. D411969

25 OCSPP 850.1730, Fish BCF, http://www.epa.gov/ocspp/pubs/frs/pub lications/OPPTS_Harmonized/850_Ecological_Effects_Test_Guidelines/Dra fts/850-1730.pdf

26 OCSPP 835.1110, Activated sludge sorption isotherm, http://www.regulations.gov/#!documentDetail;D=EPAHQ-OPPT-2009-0152-0003

. 27 TG OECD 305 states that a compound having a log P of > 3 does not have “high” lipophilicity

28 http://www.epa.gov/scipoly/sap/meetings/2008/octobe r/305_bioconcentration_flowthrough_fish_test.pdf

29 Bioconcentration in fish (MRID 49040206) and Activated sludge sorption isotherm (MRID 49040205)Page 60 of 103 increase the water solubility and product efficacy. As a result, the solubility of the end-use product Mexel 432/O is “high” (>10 mg/l) [M RID 49040204]. However, the solubility in another guideline study is given as “<10.5 mg/l” (MRID 48486702). 30

Fate in a Cooling Tower

The method of action of the Mexel 432/0 product is differe nt from most conventional treatments. The product is not focused on deliveri ng a lethal dose or trying to remove fouling that has built up over time due to ineffective on-going control. Used on a cleaned system, the Mexel 432/0 is intended to prev ent fouling by creating a microsc opic layer of a filming amine that largely controls fouling from progressing. This film prevents biofilms from gaining a
foothold that can lead to corrosi on, deposits, and poor heat transfer . This also helps prevent the build-up of layers of fouling that are hard to penetrate and allow some microbes become resistant to conventional treatments. When these probl ems are prevented, the amount of chemicals
introduced to the environment for routine treatm ent and remedial chemical treatment and other special maintenance (e.g. acid tube cleani ng) is substantially reduced (MRID 49040221).



### Environmental Fate

Hydrolysis

The alkyl trimethylenediamines compound, 1 -(alkyl* amino)-3-aminopropane diacetate (applied as Duomeen-C Diacetate, 51.9% a.i. in isopropanol), has been shown to be hydrolytically stable under abiotic and buffere d conditions over the pH 5-9 range and under
abiotic and unbuffered conditions in deionized water over a 30-day incubation period (MRIDs 40062413, 41069001, and 93034010).

Photodegradation in Water

Photodegradation in water is not expected to be a signifi cant route of dissipation for Ncoco-1,3-diaminopropane. The UV Visible absorption spectru m study indicates that the maximum sorption is in the range of 202-218 nm of wavelength, but a small amount of absorption does occur from 290-350 nm (MRI D 49040202). The photodegradation in water study requires light that is filt ered to remove wavelengths below 290 nm, and the study will not provide any useful information on the dissipa tion of N-coco-1,3-diaminopropane in the
environment.

30 Sinning, May 16, 2011Page 61 of 103 Aerobic Aquatic Metabolism

The registrant has submitted numerous articles on the degradation of surfactants, and these articles (1) did not addre ss the persistence of parent alky lamines (or suitable surrogate) in sediment and water and (2) did not provide information on the pe rsistence of the reduced-length chain degradates of alkyl amines.

Anaerobic Aquatic Metabolism

The registrant has submitted numerous liter ature studies on the metabolism of various surfactants (Curcio and Ghillebaert, 2013). So me of these studies related to specific microorganisms that can use diamine molecules as a sole carbon source. The significance of these studies for the degradation of Duomeen C is unclear because, in general, the degradation of alkylamines is dependent upon a consortium of microorganisms (Nguyen et al. 2008) and a particular bacterium may or may not be ubiquito us in wastewater treatment. These studies included Cerniglia and Perry (1975), Nguyen et al. (2008), and van Gi nkel et al. (2008). Cerniglia and Perry (1975) studied the degrada tion of monoamine and diamine molecules by the
aerobic bacterium Mycobacterium convolutum . It is not clear if this study is useful because the degradation of propylamines may not be repr esentative of Duomeen C, which contains a diethylene amine functional group. This study do es not specifically address any long-chain
carbons such as the ones in the Duomeen C molecule. Nguyen et al (2008) studied the effect of anaerobic conditions and the presen ce of a denitrifying bacterium Pseudomonas stutzeri on the degradation of long-chain alkyl amines, including cocoamine (C 8 -C 18 aliphatic saturated chain), oleylamine (C 18 amine chain containing double bond), and tallowamine (C 18 amine chain containing double bond). For all of these comp ounds, degradation occurred by deamination followed by beta-oxidation of the C 8 -C 18 alkyl chains. Van Ginkel et al. (2008) studied the effect
of the bacterium Pseudomonas sp . BERT on the degradation of amines containing C 3 -C 18 alkyl chains. In all cases, degradation occurred by deamination followed by beta-oxidation of the alkyl chains, with successive formation of alka nal groups (alkane chain with aldehyde functional group) and fatty acids (carboxylic acids) that degrade to CO 2 , water, and bacterial biomass. However, none of the literature citations provide d any estimates of half-life of these metabolic
intermediates.

Leaching

­ Adsorption

­ Desorption

ATMD was tightly sorbed onto five soils with Kf (whole soil) sorption values of 14,454- 50,898 ml/g (mean of 34,016 L/kg) and sorption values onto organi c carbon (Koc) of 696,677- 4,551,033 L/kg (mean of 1,926,433 L/kg). Nearly all (> 99 %) of Duomeen C was sorbed in the study (MRID 49040206). Sorption was related to cation exchange capacity (CEC) with r 2 ofPage 62 of 103 0.55 which indicates that sorption is a function of clay content (r 2 =0.16), organic carbon content (r 2 =0.21), and pH (r 2 =0.33) 31

. Because sorption to soil was not primarily a function of organic carbon content, the Agency used the mean Kf value of 34,016 L/kg to calculate Koc sorption in sediment that may receive ATMD residues from cooling towers. This approach was based on the “Guidance for Selecting Input Parameters in Modeling the Envi ronmental Fate and Transport of Pesticides”
from the Environmental Fate and Effects Division of OPP. 32 The input parameters for the EXAMS model, which represents surface water, were followed for ATMD because sorption was not primarily related to soil organic carbon conten t. The mean Kf of 34,016 L/kg was divided by each sediment organic carbon content listed in Table 20 below (0.002, 0.01, 0.02, 0.04, and 0.05 % as decimal) and each derived Koc was us ed in the General Population and Ecological Exposure from Industrial Rel eases module of E-FAST.

Bioconcentration in Fish

The bioconcentration in fish study includes experiments on bioconcen tration of parent ncoco-1,3-diaminopropane in bluegill sunfish ( Lepomis macrochirus ). For the ed ible, non-edible, and whole fish, the steady-state bioconcentra tion factors were 180X, 525X, and 378X for the 0.85 ug/l rate and 82X, 610X, and 388X for the 7.2 ug/l rate, respectively. For the 0.85 ug/l treatment, the 50 % depuration time ranged from 21-30 days for the non-edible and whole fish tissue. However, it was not possible to determ ine the depuration time for the edible tissue
because the concentrations were close to th e LOQ. For the 7.2 ug/l treatment, the 50 % depuration times were 17, 8.5, and 9.2 days for the edible, non-edib le, and whole fish, respectively.

Sorption to Activated Sludge

Duomeen C was tightly sorbed to activate d sludge. By 4-6 hours, 71-92 % sorption of Duomeen C was observed (mean of 83 %). By 12-24 hours, 94-98 % sorption (mean of 96 %)
was observed. The calculated Kf and Koc values for a 24-hour sorption test were 39,753 and Koc of 105,222 ml/g, respectively (MRID 49040205).

The above sorption interval times and % sorp tion values in MRID 49040205 were based on the preliminary portion of the study to determine the appropriate equilibrium time used in the final portion of the sorption to activated sludge study. According to the FAO 33 , the Hydraulic Retention Time in the aeration tanks usually ra nges from 3-8 hours but can be higher with high

31 Linear regression run on hydrogen ion concentrations and not logarithmic pH value

32 http://www.epa.gov/oppefed1/models/w ater/input_parameter_guidance.htm

33 http://www.fao.org/docrep/t0551e/t0551e05.htmPage 63 of 103 BOD wastewaters. According to Boethling 34 , a “reasonable” retention time for full-scale systems is 6-8 hours. As a result, the sorption the sorption data from 4-6 hours are appropriate for environmental modeling.

Activated Sludge Respiration Inhibition (ASRI)

According to the ASRI study (MRID 49040218), the IC50 value for ATMD was 22 mg/l with a 95 % confidence interval of 10-30 mg/l. Th e percent respiration in hibition ranged from - 1.5 % at 10 mg/l to 77.8 % at 30 mg/l with no concen tration intervals between. As a result, it
cannot be concluded with reasonable c onfidence that the activated sludge IC 50 is greater than 20 mg/L, which is the OPP threshold used to determ ine the type of WWTP biodegradation testing to perform to indicate the percent removal via biodegradation by activated sludge microorganisms. 35

Biodegradability in Wastewater Treatment

ATMD is not expected to degrade rapidly in wa stewater because it was not determined to be readily biodegradable in an OECD 301D Clos ed Bottle test (MRID 49040207) . At 2 mg/l of ATMD, the registrant reported th at 69 % of the theoretical oxygen demand (ThOD) was reached by 28 days, and therefore ATMD should be consider ed to be readily biod egradable. However, this result does not meet the pass criterion esta blished for this guideline. The OECD 301D test guideline criterion for ready biodegradability in a Closed Bottle test is 60 % of ThOD in a 14- day period, and this 14-day period starts when 10 % of ThOD disappears and must end by before day 28 of the test. 36 In the study, 10 % ThOD disappearance occurred at approximately 8 days, and the maximum percent ThOD disappearance in any 14-day window was 42 % (from 8-22 days).

34 November 22, 2013 e-mail from Bob Boethling of EPA to Pat Jennings of EPA

35 November 22, 2013 e-mail from Bob Boethling of EPA to Pat Jennings of EPA

36 P. 3, OECD 301, http://www.oecd.org/chemicalsafe ty/risk-assessment/1948209.pdfPage64of103Table 21. Chemical, Physical, and Environmental Fate Properties of Duomeen C from EPI-Suite 4.11 and Guideline StudiesN-coco-1,3-diaminopropane homologGuidelineGuideline(OCSPPnumberunlessspecified)UnitC8C10C12C14C16C18Source/Comment (EPI-Suite4.11 or MRIDNumber)Percentage ofeach homologin Duomeen C830.1550 % 4 5.3 45.3 16.2 9.5 11.1 49040203MolecularformulaNone None C11H26N2C13H30N2C15H34N2C17H38N2C19H42N2C21H46N2EPI-SuiteSmiles code None NoneCCCCCCCCNCCCNCCCCCCCCCCNCCCNCCCCCCCCCCCCNCCCNCCCCCCCCCCCCCCNCCCNCCCCCCCCCCCCCCCCNCCCNCCCCCCCCCCCCCCCCCCNCCCNEPI-SuiteMolecularweightNone g/mol 186.34 214.40 242.45270.51 298.56 326.61 EPI-SuiteRelativedensity830.7300 g/cm30.844848670222oC0.964842250224oCMelting point 830.7200oC Not available (product is a mixture of crystals,solids, and viscous liquid at room temperature)484867024302920222oCBoiling point 830.7220oC 3024848670243029202Watersolubility830.7840 mg/lHigh solubility (>10 mg/l) of diamine surfactant complex based on presence of adjuvants and dispersants49040204FormulatedDuomeen C<10.5 mg/l (maximum concentration of diamine surfactant complex in water)48486702FormulatedDuomeen CVaporPressure (mmHg)830.7950mmHg6 (formulated product including liquid phase)4302920225oCHenry’s Law Noneatmm3mol-1Not calculated because of uncertain vapor pressure and water solubility. Not applicablePage65of103N-coco-1,3-diaminopropane homologGuidelineGuideline(OCSPPnumberunlessspecified)UnitC8C10C12C14C16C18Source/Comment (EPI-Suite4.11 or MRIDNumber)Log P (logKow)830.7550Unitless-3 -1.9 -0.8 0.4 1.6 2-2.549040203Weightedaverage LogKow of 0.2Hydrolysis 835.2120 Days Stable at pH 5, 7, and 9400624134106900193034010For formulatedDuomeen CPhotodegradation in water835.2240 Days Assumed to be essentially stable to photodegradation because of limitedsorption of UV light by active ingredient4904020249208801Koc values tobe used forEFAST model835.1230 L/kgFor modeling, use Koc derived from mean Kf of 34,016 L/Kg based on policy guidance for the EXAMSmodel stating that if sorption is not related to organic carbon, use the mean Kf.37EXAMS model simulates aquatic environment. The Koc values below were calculated by division of theKf by the Sediment OC values listed below.Based onresults fromMRID49040206(below)Sediment OC values for EFAST Modeling (decimal) Derived Koc Values based on Mean Kf (L/kg)0.002 1.7 x 1070.01 3.4 x 1060.02 1.7 x 1060.04 8.5 x 1050.05 6 x 105Leachingadsorptiondesorption tosoil835.1230 ml/gKfof 14,454-50,898 L/kg, Koc of 696,677-4,551,033 L/kg1/n ranged from 0.48 to 0.82 (<1)Straight arithmetic mean of 34,016 L/kg for Kf and 1,926,433 L/kg for Koc>99 % sorption for all 5 soils starting at the 2-hour equilibrium time (24 hours used in final test)Sorption related to cation exchange capacity (CEC) with r2of 0.55 which indicates that sorption is afunction of clay content (r2=0.16), organic carbon content (r2=0.21), and pH (r2=0.33)3849040206Sorption offormulatedDuomeen C tofive soilsTexture pH Clay(%)OC(%)CEC(meq/100g)Kf (L/kg)(fromstudy)Koc (L/kg)(fromstudy)1/n (fromstudy)37http://www.epa.gov/oppefed1/models/water/input_parameter_guidance.htm38Linear regression in Excel with (x) values of run on Hydrogen ion concentration and not pHPage66of103N-coco-1,3-diaminopropane homologGuidelineGuideline(OCSPPnumberunlessspecified)UnitC8C10C12C14C16C18Source/Comment (EPI-Suite4.11 or MRIDNumber)Silt loam 7.1 25 4.2 24.1 50,898 1,211,857 0.71Sandy loam 6.1 17 2 17.2 38,362 1,968,100 0.70Clay loam 5.3 29 4.3 22 29,957 696,677 0.82Loamy sand 5.6 11 1.2 11.7 14,454 1,204,500 0.75Clay 7.7 44 1.8 25.4 36,408 4,551,033 0.48Aerobicaquaticmetabolism835.4300 DaysPersistence of parent alkylamines (or suitable surrogate) in sediment and water and information on thepersistence of the reduced-length chain degradates of alkyl amines not provided.49208802Anaerobicaquaticmetabolism835.4400 DaysDegradation occurred by deamination followed by beta-oxidation of the alkylchains, with successiveformation of alkanal groups (alkane chain with aldehyde functional group) and fatty acids (carboxylicacids) that degrade to CO2, water, and bacterial biomass. However, none of the literature citationsprovided any estimates of half-life of the metabolic intermediates.49208803Activatedsludgesorption835.1110%,L/kg71-92 % sorption by 4-6 hours (mean of 83 % sorption)94-98 % sorption by 12-24 hours (mean of 96 % sorption)Kf of 39,753, Koc of 105,222 L/kg49040205For wholeDuomeen CReadybiodegradability835.3110OECD301D%Readily biodegradable (69 % biodegraded by 28 days in Closed Bottle test)49040207For wholeDuomeen CformulationActivatedsludgerespirationinhibition850.3300 mg/lEC50value was 21.9 mg/L.49040218For wholeDuomeen CformulationBioconcentration in fish39850.1730UnitlessEdible, non-edible, and whole fishBCF of 180X, 525X, and 378X for the 0.85 ug/l rateBCF of 82X, 610X, and 388X for 7.2 ug/l rate50 % depuration occurred at 21and 30 days for non-edible and whole fish at 0.85 ug/l50 % depuration occurred at 17, 8, and 9 for edible, non-edible and whole fish at 7.2 ug/l49040210For wholeDuomeenformulation39BCF predictions should increase as the water solubility decreases and log Kow increases.Page 67 of 103 APPENDIX A REFERENCES

Bisinger, Jr., E.C. Hydrolysis Study: Envir onmental Fate Data Requirements. Unpublished study performed and submitted by Akzo Chemie America, Chicago Il. MRID 40062413

Bisinger, Jr., E. C. April 14, 1989. Hydrolysis of Duomeen-C Acetate: E nvironmental Fate Data Requirements. Unpublished study performed and submitted by Akzo Chemicals, Chicago, IL. MRID 41069001

Cerniglia, C.E., and Perry, J.J., 1975. Metabolism of n-propylamine, isopropylamine, and 1,3- propane diamine by Mycobacterium convol utum. J. Bacteriol., 124(1): 285-289.

Curcio, L.N. and F. Ghillebaert. Septem ber 4, 2013. Response to data requirements deficiencies: OCSPP 835.4400-An aerobic aquatic metabolism. Unpublished study sponsored and submitted by Mexel USA, LL C, Arlington, VA. MRID 49208803.

Curcio, L.; Ghillebaert, F. (2013) Response to Da ta Requirements Deficiencies: Aerobic Aquatic Metabolism. Project Number: MEXEL/432/0. U npublished study prepared by Ecotox and The Solutous Group. 131p. MRID 49208802

Curcio, L.; Ghillebaert, F. (2013) Environmental, Ecological and Health Effects (Tier 1) for Duomeen C, the TGAI in the EP Mexel 432/ 0. Unpublished study prepared by Mexel USA, LLC. 702p. MRID 49040219

Curcio, L.; Ghillebaert, F. (2013) Requested Su pplemental Data for Waiver Passing Technical Screen: Photodegradation in Water. Pr oject Number: MEXEL/432/0. Unpublished study prepared by Ecotox and The Solutous Group. 34p. MRID 49208801

Ellison, F. (1993) Duomeen C: Physical and Chemi cal Characteristics of Duomeen C: Physical State, Boiling Point, Specific Gravity, Solubi lity, Vapor Pressure, pH, Stability, Oxidizing or Reducing, Explodability and Viscosity: Fi nal Report: Lab Project Number: 00459-002. Unpublished study prepared by Case Cons ulting Labs, Inc. 19 p. MRID 43029202

Farnback, M. July 16, 2012. Determination of the Partition Coefficient (1-octanol/water) for Duomeen C. OCSPP Guideline 830.7550. Unpublis hed study performed by Casco Adhesives AB, Sweden, and submitted by Mexel Industries, France. MRID 49040203

Kendall, T.Z and W.B. Nixon. March 13, 2013. An alytical Method Verification of Duomeen C in Freshwater Wildlife Intern ational Ltd. Project No. 709C-101. Unpublished study performed by Wildlife International, Easton, MD, and su bmitted by Mexel Industries, Arlington, VA. MRID 49040201

Murrell, J.R. and W. B. Nixon. April 5, 2012. Determination of the Ultraviolet-Visible Absorption Spectrum of Duomeen C. Wild life International Pr oject No. 709C-103. Unpublished study conducted by Wildlife Interna tional, Easton, MD, and submitted by Mexel Industries, Arlington, VA. MRID 49040202

Nguyen, P.O., van Ginkel, C.G. and Plugge, C. M., 2008. Anaerobic degradation of long-chain alkylamines by a denitrifying Pseudomonas stutzeri . FEMS Microbial. Ecol. , 66(1) :136-142Page 68 of 103 Rausch, L. (1990) Akzo Chemicals, Inc. Ph ase 3 Summary of MRID 41069001. Hydrolysis of Duomeen-C Diacetate. Prepared by AKZO CHEMICALS INC. 10 p. MRID 93034010

Schaefer, E.; Ponizovsky, A. (2012) Duomeen C: Activated Sludge Sorp tion Isotherm. Project Number: 709E/103/OCR. Unpublished study prepar ed by Wildlife Inte rnational, Ltd. 65p. MRID 49040205

Schaefer, E.C. and Twilley, B.C., 2011 . Duomeen C: An activated sludge, respiration inhibition test. Project ID 709E-1 01 , performed on beha lf of Mexel Industries, SAS. MRID 49040218

Schaefer, E.C. and Ponizovsky, A.A., 2012b. Duomeen C: Adsorption/Desorption Characteristics In Five Representative Soils. Project ID 709E-102, Wildlife International, Ltd., Performed on behalf of Mexel Industries, SAS. 124 pp. MRID 49040206

Sinning, D. December 2, 2010. Physical and Chemi cal Characteristics of Mexel 432/0: Color, Physical State, Odor, Oxidation/Reduction: Chemical Incompatibility, Flammability, pH, Viscosity, and Relative Densit y. Project Number: 4800/01. Unpublished study prepared by Case Consulting Laboratories, Inc. 9 p. MRID 42022502

Sinning, D. . May 16, 2011. Physical and Chemical Characteristics of Duomeen C: Color, Physical State, Odor, Stability, pH, UV/Vis, Boiling Point, Density, Dissociation Constant, Octanol/Water Partition Coefficient and Sol ubility: Final Report. Project Number: 4870/02. Unpublished study prepared by Case Consu lting Laboratories, Inc. 32 p. MRID 48486702

Thomas, S.T., Kendall, T.Z., and Gallaghe r, S.P., 2013. Duomeen C: A flow-through bioconcentration test with th e bluegill (Lepomis macrochirus). Project ID 709A-110, Wildlife International, Ltd., Performed on behalf of Mexel Industries, SAS. 115 pp. MRID 49040210

US EPA, 2012b. Estimation Programs Interface SuiteTM for Microsoft® Windows, v 4.11. United States Environmental Protec tion Agency, Washington, DC, USA http://www.epa.gov/oppt/exposur e/pubs/episuitedl.htm

van Ginkel, C. G., Louwerse, A., and van der Togt, B., 2008b. Substrate specificity of a long chain alkylamine-degrading Pseudomonas sp isolat ed from activated sludge. Biodegradation 19( 1): 129-136

van Ginkel, C.G. May 23, 2012. Biodegradability of n-coco-1,3-diamino-diamineopropane (CAS 61791-63-7) in the closed bottle test (OECD TG 301 D). Unpublished study by Akzo Nobel Arnhem, study number: T12018C. MRID 49040207

Velea, Luminita. February 26, 2013. Water So lubility for Mexel 432/P, EPA Reg. No. 84034-1. Unpublished study performed by Technology Sciences Group, Washington, DC, and submitted by Mexel Industries, Arlington, VA. MRID 49040204Page 69 of 103 

### APPENDIX B: HUMAN HEALTH TOXICITY DATA

Subchronic Toxicity

An acceptable 90-day oral toxicity study (MRID 49092801) was submitted and reviewed. In this study, N -(coco alkyl) trimethylenediamine (94% a.i., Batch No.: S000904)
was administered to 10 Wistar RjHan:WI rats/sex/dose via or al gavage as a suspension at dose levels of 0 (C), 0.1, 0.4, 1.5, or 6 mg/kg/day for 7 days/week for a period of 90 days at a volume of 4 ml/kg. There were two recovery gro ups consisting of 5 animals per sex: one was observed for 28 days and one for 90 days fo llowing the last compound administration.

Test item related clinical signs were observed in 1.5 and 6.0 mg/kg/day groups and recovery groups. Signs included slight to severe saliva tion, half-eyelid closure, vocalization, temporary stertorous respiration, oral a nd nasal discharge, dyspnea, weight loss and piloerection.

Three mortalities in the main groups, (two fe male from 6.0 and one male from 1.5 mg/kg/day groups) and 2 mortalities in high dose females of the 90-day recovery group were observed. Dosing error might have been the cause in three of the animals. No cause of death could be established in the remaining two females treated at 6 mg/kg/day.

During the treatment period (days 1 to 90 in th e main study and recovery high dose group male animals), there was a statistically significant decrease in overall body weight gain [33%] and food consumption [16%] compared to the corres ponding controls. No change was seen in the
females.

No test item related effect occurred in hematology and ur ine parameters and clinical biochemistry parameters in male and females of any group except decreases in total protein in the 1.5 and 6.0 mg/kg/day females when compared to the control.

No effect on organ weight in male and female animals of treated group and recovery group was
observed which could be considered as a treatment related effect except a decrease in absolute liver weights in 6.0 mg/kg/day males, increase in relative kidney weights in 28-day recovery males, increase in relative adrenal weights in 6.0 mg/kg/day male and females, and increase in relative epididymides weight in 6.0 mg/kg/day males. No histopathology changes were noted that could account for the these changes.

At the terminal sacrifice of the main study and recovery animals, macr oscopic findings observed were considered to be spontan eous and not treatment related

Histopathologically, test item-related changes we re seen in the small intestine (ileum and jejunum), mesenteric lymph node, spleen, bone marrow (sternum) and trachea at 1.5 mg/kg/day and above. After the 28-day rec overy period, treatment- related changes in the jejunum, ileum and mesenteric lymph node were still present in animals of this dose group. Changes noted in thePage 70 of 103 spleen had partially regressed and bone ma rrow (sternum) and tracheal changes had fully regressed. After 90 days of rec overy, test article-related chan ges in the jejunum, ileum and mesenteric lymph node had partiall y regressed. No test article-rela ted changes were noted in the spleen, bone marrow (sternum) and trachea.

The NOAEL is 0.4 mg/kg/day. The LOAEL is 1.5 mg/kg/day based on a decrease in body weight gain and food consumption in males and histopathology changes in the gastrointestinal tract in males and females.

Developmental Toxicity

A developmental toxicity study was not conducted for N-(coco al kyl)trimethylenediamine [also referred to as N-coco 1,3-diaminopropane]. Inst ead, the registrant cited a study summary that was presented in the 2008 European Union Ri sk Assessment Report for tallow alkyl amines. This study was conducted on octadecenylamin e, whose structure is shown below:

The summary of this study is presented below:

“In the main study, groups of 28 pregnant females were treated orally (gavage) with dosages of 10, 40 or 80 mg/kg bw/day or with the vehicle (M azola corn oil) during gestation days 6 to 15. During the study animals were examined daily. Any clinical signs of toxicity including physical
or behavioral abnormalities we re recorded. Individual body wei ghts and food consumption were recorded on gestation days 0, 6, 9, 12, 16, and 20. Tw o animals in each group were selected to be sacrificed and necropsied after treatment on ge station day 15 to determine the appearance and severity of gastrointestinal tr act irritation. On gestation day 20 caesarean section was performed on all surviving animals. The numbers of viable fe tuses, early and late resorptions as well as the number of corpora lutea were recorded. Fetuses we re examined for external, visceral and skeletal
abnormalities.”

“All animals survived to scheduled sacrifice. Outw ard clinical signs of to xicity were observed at the 40 and 80 mg/kg bw/d dose levels. The obser vations most likely indicated a generalized
irritative effect of the test s ubstance as characterized by rales, salivation, unkempt appearance and changes in the amount, color and consistency of the feces. However, no other signs of treatment-related gastrointestinal irritation or other internal changes were observed at the gestation day 15 and 20 necropsies. More pronounced signs of toxicity were apparent only in the 80 mg/kg bw/d dose group and included emaciation, rough coat and dark red material around the eyes, nose and/or mouth. Similar clinical signs were infrequently noted during the post-dosePage 71 of 103 observations. Dose-dependent body we ight loss (during gestation da ys 6-9) or reduced weight gain (during gestation days 12-16), along with a corresponding reduction in food consumption occurred during the treatment period in the 40 and 80 mg/kg bw/d dose groups. Net body weight gain (adjusted for gravid uterine weight) was al so lower at these levels. Following cessation of treatment (days 16-20), increase in weight gain and food consumption were noted at both dose
levels. No such effects were observed in the dose group treated with 10 mg/kg bw/d. Caesarean section data obtained from the treated groups did not reveal any me aningful differences (concerning number of corpora lu tea, implantation sites, viable fetuses, fetal sex and fetal weight) when compared with the controls. Fe tal evaluations of type and frequency of malformations and variations did not reveal any indications for a treatme nt related teratogenic effect. In summary, oral administration of oc tadecenylamine to pregnant rats produced dosedependent maternal toxicity in the 40 and 80 mg/kg bw/d dose groups. No indications of an embryotoxic, fetotoxic or tera togenic effect were observe d at any tested level.”
\

“ A NOAEL/maternal toxicity of 10 mg /kg bw/d and a NOAEL/developmental toxicity of > 80 mg/kg bw/d can be derived from the study .”

Reproduction and fertility effects

No data on reproduction and fert ility effects was submitted for the active ingredient N-(coco alkyl)trimethylenediamine [also referred to as N-coco 1,3-diaminopropane]. Instead, the registrant cited a summary of a study conducte d on tallow alkyl amines. This study was conducted according to OECD test guideline 421 (developmental/re productive screening assay).

The summary of this study is presented below.

Groups of 10 rats (Crl:CD (SD) BR) per sex were treated with dosages of 0, 12.5, 50, and 150 mg/kg bw/day by gavage (administration volu me 10 ml/kg bw/day) using sesame oil as a vehicle. Males were treated daily from 14 days prior to mating until the end of the mating period for a maximum of 28 days. Females were treated daily for 14 days befo re start of the mating period, throughout the same, during pregnancy and until day 3 of lactation. The animals were
mated one male with one female.

At daily doses of 150 mg/kg bw 6/10 males and 5/10 females died between day 9 and day 25 of treatment (during the premating and mating period ). At daily doses of 50 mg/kg bw 1/10 males and 1/10 females died on day 13 respectively on day 24 of treatment. No animals died at 12.5 mg/kg bw/day, and in the control group 1 female died by accident.Page 72 of 103 Clinical observations at 150 mg/kg bw/day reve aled salivation after tr eatment, hunched posture and in some cases soft stools and piloerection. Th e only clinical sign present at 50 mg/kg bw/day was salivation. No changes were seen at 12.5 mg/kg bw/day.

Body weight loss of about 22 g at the 150 mg/kg bw dose group and statistically significant (p > 0.01) lower body weight gain at the 50 mg/ kg bw dose group during the premating period together with a lower mean food consumption was observed in the males. Also in the females body weight loss of about 17 g at the 150 mg/kg bw dose group and statisti cally significant lower body weight gain at the 50 mg/kg bw dose group t ogether with a lower mean food consumption during the premating period was observed.

At sacrifice of the parental animals organ wei ghts of ovaries, testes and epididymides were determined from all experimental groups . Histopathology was carri ed out on testes, epididymides and ovaries of the controls and of the animals of the 150 mg/kg bw dose group. A statistically significant (p> 0.01) lower absolute and relative weight of epididymides and a statistically significant (p> 0.01) higher value of relative test is weight was observed at 150 mg/kg bw/day. No significant differences were noted in ovary weights among the various experimental groups. Histopathology of testes and epididymides of high dose group animals did not show any compound-related changes. In partic ular, no changes were seen in the testicular staging performed in the PAS-hematoxylin stained s ections of final sacrificed animals of control and of the high dose groups. In the ovaries, m oderate increased freque ncy of atrophic corpora lutea was seen in the animals of the high dose gr oup which died or were s acrificed, compared to the controls, this finding was considered a se condary effect to the decrease in body weight growth induced by treatment in this group. At the dosages of 150 mg/kg bw/day only 3 females out of 7 mated females had positive vaginal smear s and of these only one was pregnant, but with only implantation sites and no live p ups. At this dosage level also the mean pre-coital interval was longer (13.4 days) than that of the control gr oup (2.3 days). With regard to the mating index in the control, the 12.5 and the 50 mg/kg bw dos e level groups 9/9 (100 %), 9/10 (90%) and 9/9 (100%) mated females were sperm positive. With re gard to the fertility index 9/9 (100%), 8/10 (80%) and 7/9 (78%) of the mated females became pregnant in the control, the 12.5 and the 50 mg/kg bw dose level groups. Mean pre-coital time and parturition were unaffected in the low and mid dose treated groups.

With regard to the conception rate in the cont rol, the 12.5 and the 50 mg/kg bw dose level groups 9/9 (100%), 8/9 (89%) and 7/ 9 (78%) of the sperm positive females became pregnant and delivered live pups. Numbers of corpora lutea ha d not been determined during this study. Thus, any pre-implantation loss was not evaluated. Stai ning for the presence of implantation sites was only performed with the ut eri of apparently non-pregnant fema les. The mean number of visible implantation sites per dam in the control, the 12.5 and the 50 mg/kg bw dose level groups were 17.6, 13.9 and 15.0. There were no stillborns or litter s with only implantati ons in the control,Page 73 of 103 low, and mid dose groups. The mean number of total pups born per litter was 16.9, 12.3 and 14.3 in the control, the 12.5 and the 50 mg/kg bw/d ay dose groups. Thus, the mean litter index for post-implantation loss was calculated to 3.4, 9.9 a nd 4.5% in the control, the low and the mid dose groups.

No effects were noted on the pup sex ratio. No abnormalities were observed in any pup either at birth or at autopsy on day 4 of lactation neither in the 12.5 nor in the 50 mg/kg bw/day treated groups. Lower mean values of live born per litter and of pups per litter alive at day 4 were found for both the low and the intermediate dose groups in comparison to those of the control group, however, the decreases were not dos e dependent and the differences were statistically significant for the 12.5 mg/kg bw dose group only. Thus, thes e findings were considered unlikely to be related to the compound. A slightly lower pup body weight was observed in the 50 mg/kg bw/day treated group in comparison with the contro l group at birth and at day 4 of lactation but not for the pups of the 12.5 mg/kg bw/day treated group.

Based on findings of general toxicity (death, cl inical signs, reduced body weight gain) at daily dosages of 50 mg/kg bw/d a NOEL/syst emic toxicity of 12.5 mg/kg bw/d can be derived from the study. Based on the finding s of a lower fertility index and a lower conception rate at daily dosages of 50 mg/k g bw/d a NOEL/fertility of 12.5 mg/kg bw/d can be derived from the results of this screening study.

In addition to the above cited study, a comb ined repeated dose toxicity study with reproduction/developmental toxicity screening (performed according to OECD guideline 422) was conducted with coco alkylamine (CAS # 617 88-46-3) and was submitted and reviewed by the Office of Pesticide Programs (MRID 47646101). Co co alkyl amine was assessed as part of a
risk assessment conducted in 2009 by the Health Effects Division of OPP for inert uses of a group of primary alkyl amines in pesticide form ulations. Note that coco alkylamine is a chemical listed in the 2008 Europ ean Union risk assessment, but is not listed in the OPP RED for alkyl trimethylenediamines.

Structure:Page 74 of 103 Study summary

In a Combined Repeated Dose Toxicity Study with the Reproduction/Developmental Toxicity Screening Test (MRID 47646101), Amines, coco alkyl (CAS # 61788-46-3; Batch # 830668; 100.4% a.i.) was administered to 10 Crl:CD(SD) rats/sex/dose by gavage at dose levels of 0, 5, 20, 40 or 80 mg/kg bw/day. The vehicle and diluent were reverse osmosis deionized water and glacial acetic acid, respectively. Dosing began 14 days before the c ohabitation period and continued th rough the day before sacrifice. Surviving male rats received at least 46 doses. For female rats, dosing contin ued through lactation day (LD) 4 for rats that delivered a litter or GD 24 for rats that did not deliver a litter. Females received a total of 38-42 doses. Five animals/sex/group were tested in the FOB followed by motor activity testing on the day of scheduled sacrifice.

Two high-dose males were sacrificed moribund, one each on study day 18 and 42. Clinical signs in these animals included rales, salivation, urine st aining, weight loss/emaciation, ungroomed coat, dyspnea, and gasping; at necropsy gavage erro r was confirmed for one animal, but a cause of death
was not determined for the other animal. Treatment-rela ted clinical signs of toxicity in the 40- and 80- mg/kg/day males included rales in 8 and 10 animals, respectively, and excessive salivation in 5 and 8 animals, respectively. Among female rats, clinical si gns of toxicity included excessive salivation in 1 and 2 animals, respectively during premating, in 1 and 4 an imals, respectively, during gestation, and in 0 and 1 animal, respectively, during lactation.

Body weight, body weight gain, and food consumpti on by the 5- and 20-mg/kg/day groups was similar to the control group levels throughout the study. Body weight gain was slightly or significantly less than that of controls for the 40-mg/kg/day males beginning on the third week of the study and for the 80-mg/kg/day males from the beginning of the study. Mean weekly body weight gains for the 40- and 80-mg/kg/day
males were 5-87% and 35-71%, respectively, of the control group level resulting in an overall weight gain for the study 65% and 20%, respectively, of the control level. The high-dose group showed a mean weight loss for the day 36-43 and 43- 46 intervals. Final body weight of the 40- and 80-mg/kg/day males was 92 and 81% of the control value. Food consumption by the 40-mg/kg/day males was significantly less than that of the control group during days 36-43 (p 0.05; 87% of control). Food consumption by the 80- mg/kg/day males was significantly less than that of the controls during days 29-36, 36-43, and overall (p 0.05 or 0.01; 69-85% of controls).

For females during premating, body weight, weight ga in, and food consumption were similar between the treated and control groups. Body weight and weight gain were not affected during gestation. Food consumption by the high-dose females during gestation was significantly less than that of controls for GDs 0-12 and overall (p 0.05 or 0.01; 83-85% of cont rol level). During lactation, body weight of the high-dose group was significantly less than that of contro ls on days 3 and 4 (p 0.05 ; 90% of control level). Body weight changes during lactation were highly variable for all treated and control groups. Food consumption by the high-dose group during lactation da ys 1-4 was 79% of the control level but did not attain statistical significance.Page 75 of 103 During the FOB, no treatment-related changes in home cage, handling, or open field behavior were observed. Sensory reactions, grip strengths, air right ing response, and landing foot splay were similar between the treated and control groups for males a nd females. High-dose males had markedly reduced number of movements and time spent in movement (overall 50% and 42%, respectively, of control levels). In general, both paramete rs were reduced after the first 20 minutes and for the remainder of the session. Statistical significance was not attained due to large variability in the data. No differences between treated and control females were seen for motor activity.

No biologically important differences were observed in the male or female rats at doses up to 80 mg/kg/day in the hematology or clinical chemistry parameters. At necropsy, terminal body weight and absolute and relative (to brain) liver, kidney, and heart weights were significantly (pO.O5 or 0.01)reduced in the 80-mg/kg/day males. High-dose males also had significantly reduced organ weightrelative-to-body weight of the testes, brain, and ad renals, although the absolute weight of these organs was similar to the control group value. No clear effe cts on organ weight were seen in female rats. No treatment-related gross lesions were observed in ma le or female rats at terminal sacrifice.

Microscopically, a dose-related increase in the incidence and severity of erosions, hyperplasia/hyperkeratosis, and necrosis was observed in the stomach of males and females administered 20 mg/kg/day and higher. Thymic atrophy was found in 80-mg/kg/day males and females and in the 20- and 40-mg/kg/day females. Dose-related increases in the incidence and severity of macrophage
infiltration occurred in the ileum of males at the two highest doses, in the jejunum of males at > 20 mg/kg/day and in females at 40 and 80 mg/kg/day, in th e liver of high- dose males and females, and in the mesenteric lymph node of males at > 20 mg/kg/day and in females at 40 and 80 mg/kg/day. In the lymph node and liver of affected animals, the macrophages coalesced to form microgranulomas.

Estrous cycling was similar between the treated and control groups. The mean number of cycles for all groups was 2.4-2.8 during the premating interval . Reproduction and fertility were not affected by treatment. The mean duration of gestation and the me an number of implantation sites and corpora lutea were similar between the treated and control groups.

Litter size and mean number of pups at first litter check and the sex ratio were not affected by treatment. Pup survival was similar between the treated and cont rol groups. No treatment- related clinical signs of toxicity were observed in the pups during lactation. Offspring body weight for the 40 and 80 mg/kg/day groups was significantly less than that of the controls on lactation days 1 and 4. Body weight gain was markedly decreased at 80 mg/kg/day for lactation days 1-4 (1.8 g vs 3.0 g for controls). No treatmentrelated findings were noted on macroscopic examination of the pups.Page 76 of 103 The parental /systemic LOAEL for amines, coco alkyl in rats is 20 mg/kg/day based on microscopic lesions in the stomach, jej unum, thymus, and lymph node in males and females. The parental/ system ic NOAEL is 5 mg/kg/day. The reproductive/developmental LOAEL for Amin es, coco alkyl in rats is 40 mg/kg/day, based on decreased body weight and body weig ht gain in male and female offspring. The reproductive/developmental NOAEL is 20 mg/kg/day.

This study is classified Acceptable/Guideline and satisfies the guideline re quirement for a Combined Repeated Dose Toxicity Study with the Reproduction/Developmental Toxicity Screening Test (OECD 422) in the rat ( OPPTS 870.3650).

Chronic Toxicity

The registrant submitted no data on the chronic toxicity of the active ingredient under consideration (N-(coco alkyl)trimethylened iamine [also referred to as N-coco 1,3- diaminopropane]). Instead, the registrant cited th ree chronic toxicity studies performed with octadecylamine (stearamine). The studies cited by the registrant are summaries within the 2008 European Union Risk Assessment document. The structure of the chemical and summaries of these studies (all that was provided) are shown below.

Structure:Page 77 of 103 STUDY SUMMARIES

One chronic study involved the administration of stearic acid, a metabolite of hydrogenated tallow alkylamines at a single dose of approxi mately 200 mg/kg/day for 206 days in the diet. Another group was fed with diet containing octad ecylamine that was dissolved in corn oil (CAS 124-30-1), while a control group was not carri ed along. Food consumption and the weekly change of body weights were recorded. Gross and microscopic examinations were made on major tissues (20 organs/tissues).

Two out of five female rats died spontaneously (no details were provided). Average weight gain was 12 g in males and 58 g in females, and the animals were reported to be anorexic. Tissues
from rats fed with stearic acid showed severe pulmonary infection consisting of tracheobronchitis, lobular pneumonia, lipoid hist iocytic response, and abscess formation. No histomorphologic abnormalities were observed in the other organs. The authors concluded anorexia and increased mortalities as being s ubstance-related toxic e ffects of stearic acid. This study used one dose and is therefore li mited in its hazard characterization

.

In a second study, four groups of 24 rats (12/se x) were fed diets containing 20, 100, 200, and 500 ppm stearamine for two years (mean dose was about 1.05, 5.79, 10.68, and 27.15 mg/kg/day for 350 g males and 1.20, 5.80, 10.08, and 28.20 mg/kg/day for 250 g females). Feed consumption, growth rate, death rate, and blood cell counts for the experimental animals were comparable to
those of the control animals. Tissues examined by histopathol ogy examination included brain, viscera, gonads, skeletal muscle , bone marrow, heart, lungs, liver, spleen, kidneys, gastroenteric tract (3 levels), pancreas and lymph nodes. Th e organs examined microscopically included the heart, lungs, liver, spleen, kidneys , gastrointestinal tract (3 levels), pancreas, lymph nodes, bone marrow, brain, pituitary, adrenals, and ovary or te stis. The feed consumption, growth rate, death rate, and blood cell counts for th e experimental animals were comparable to those of the control animals. One rat receiving 500 ppm showed hist iocytic hyperplasia of the mesenteric lymph node. At necropsy, no significant differences were found between the expe rimental and control groups in the incidence and types of lesions obse rved. Having the histiocytic accumulations at 3000 ppm (seen in the 209 day-study in rats) and lesions of the sa me nature in the dog in mind, the single case of histiocytic hyperplasia in the mesenteric lym ph node of the single rat treated with 500 ppm (25 mg/kg bw/d) for 2 years (in th is study) could also be interpreted as a
treatment-related. Therefore a NOAEL of 200 ppm (10 mg/kg bw/d) is proposed for the 2- year rat studies.

In a third study, three groups of three dogs (2 females and 1 male or 2 males and 1 female) each were fed 0.6, 3.0, and 15.0 mg/kg bw/d octadecylamine ("stearamine") in co rn-oil solution that was administered by capsule once daily (5 d/wk ) A control group of dogs was given untreated feed. Dogs were housed in individual cages a nd fed once daily. Hematological examinationsPage 78 of 103 consisted of total red blood cell count, hemoglobin concentration, total and differential white cell counts and were performed on all dogs at the star t of the experiment and at 1, 2, 3, 6, 8, 11, and 12 months thereafter. The organs examined microscopically in cluded the heart, lungs, liver, spleen, kidneys, gastroenteric tract (3 leve ls), pancreas, lymph nodes, bone marrow, brain, pituitary, adrenals, and ovary or testis. The high dose group gained less weight than the control and lower-dose animals. The weight gain for the two lower-dose groups was similar to that of the controls. Blood cell counts were comparable in experimental and control animals. Only one dog died before study termination (a fter week 22); this dog was from the group receiving 15.0 mg/kg bw/d octadecylamine and suffered from anorex ia, bloody diarrhea and what appeared to be gastroenteric irritation. At n ecropsy, two animals from the high-dose group had lesions suggestive of the mesenteric lymph nodes, which were filled with pale histiocytes. Also, pale staining of the tips of the vil li of the small intestine mucosa was observed in these dogs. However, no definite lesions were identified in the intestinal tracts of these animals or in any of the other experimental animals. [No other info rmation available.] Considering the mortality associated with anorexia and hemorrhagic diarrh ea in one dog, growth depression in two other dogs, and the lymph node histiocytosis observed at 15 mg/kg bw/d as a treatment-related toxic effect, the NOAEL in dogs fed with octadecylamine (CAS 124-30-1) for 1 year was 3 mg/kg
bw/d.

Carcinogenicity

The registrant did not submit any carcinogenicity data for th e active ingredient N-(cocoalkyl)trimethylenediamine, but instead cited a st udy in the 2008 European Union risk assessment conducted on octadecylamine. The summary of that study is shown below, as printed in the 2008 European Union risk assessment.

“A 2-year toxicity study of octadecylamine ("stearamine") was conducted using SpragueDawley rats. Four groups of 24 rats (12/sex) were fed diets contai ning 20, 100, 200 and 500 ppm stearamine (reviewed by Pang, 1995, or iginal data University of Miami, 1957, Deichmann et al., 1958). A control group of animals was fed the base diet alone. The feed consumption, growth rate, death rate, and blood cell c ounts for the experimental animals were comparable to those of
the control animals. The survival rate for th is study was 17-33% including the control group. At necropsy, no significant differences were found between the experi mental and control groups in the incidence and types of lesions observed. No significant increase occurred in the incidence of lesions. [No other information available.]”

While this summary provides little information on carcinogenicity, th ere are additional pieces of information that would support th e lack of carcinogenic potential for these chemicals. The first piece of information is the mutagenicity databa se for the alkyl amine compounds assessed in thePage 79 of 103 2008 European Union risk assessment, where the da ta show these chemical s to be negative for mutagenicity in a variety of assays. The sec ond piece of information available is a structureactivity analysis conducted by OPP’ s Health Effects Division as pa rt of the 2009 risk assessment for linear alkyl amines as inerts in pesticide formulations. Using the DEREK software program for prediction of structural al erts that may indicate concern for carcinogenicity, there were no
identified structural alerts of concern for the ch emicals screened. The third piece of information available are mutagenicity data cited in the alkyl trimethylenediame RED that also showed negative results for mutagenicity.

The fourth piece of information is an analysis conducted for the N-alkyl amines and the alkyl diamines (collectively known as aliphatic amines) using th e Oncologic SAR program. This analysis was conducted by the Office of Pollu tion Prevention and Toxics, one of the major program offices within the Office of Chemical Safety and Pollu tion Prevention. Their analysis states in part, ” unlike aromatic amines, aliphatic amines ar e generally not considered to have significant carcinogenic activity unless the alkyl group is sma ll and contains reactive groups (e.g., terminal Cl/Br/I) or pro- reactive groups (e.g., unhindered terminal double bond). Although hydroxylamines of aliphatic amines can be reactiv e, they are usually too short-lived to have effects beyond local action.”Page 80 of 103 

### APPENDIX C: ECOTOXICITY DATA

Acute and chronic toxicity data from registrant-submitted studies conducted in
accordance with the 850 OC SSP Harmonized Test Guidelines are used to evaluate the potential
acute and chronic effects of AT MD to nontarget organisms. The available ecotoxicity endpoints from studies submitted by registrants are tabulated below. OPP uses the most sensitive of these endpoints (see Table 6) for assessing risk to each terrestrial and aquatic receptor group. Additionally, Web-ICE 40 (EPA 2013) has been used to predic t the acute toxicity to the fathead minnow and to cyanobacteria. Predicting the fathead LC50 allows for developing an AcuteChronic Ratio 41 (ACR; EPA 2010) for freshwater fish and subsequently predicting a chronic NOAEC for the rainbow trout, the most acutely se nsitive freshwater fish (Table 23). As presented in Table 25 and Table 26, ACRs also were calculated a nd used to extrapolate NOAECs
for estuarine/marine invertebrates and estuarine/ marine fish for which ecotoxicity studies were
not submitted.



### Toxicity to Terrestrial Organisms

Birds

Two acceptable and three supplemental acute- oral (LD50) studies categorize the AMTDs as being practically nontoxic to very highly toxic to birds (T able 22). The guideline (850.2100)
is satisfied.

40 To address data gaps in species sensitivity, the Inte rspecies Correlation Estimations (ICE) application was developed by EPA and collaborators to extrapolate acute toxi city to taxa with little or no acute toxicity data for a chemical (EPA 2013). ICE models estimate the acute to xicity (LC50/LD50) of a chemi cal to a species, genus, or family with no test data (the predicted taxon) from the know n toxicity of the chemical to a species with test data (the surrogate species). ICE models are least square regre ssions of the relationship between surrogate and predicted taxon based on a database of acute toxicity values: median effect or lethal water concen trations for aquatic species (EC/LC50; μ g/L) and median lethal oral doses for wildlife species (LD50; mg/kg bodyweight).

41 An Acute-Chronic ratio (ACR) can be used to predict chronic toxicity in aquatic organisms when the acute toxicity is known but chronic data are absent or limited/i ndefinite (USEPA 2010). OPP derives ACRs for pesticides based on the ratio of the acute toxicity of a chemical (expressed as an LC50 or EC50 value from a valid acute study) to its chronic toxicity (expressed as a NOAEC value from a valid chronic st udy). Ideally, the acute and chronic toxicity data used to derive the ACR should be from the same test species. This ACR is then applied to a species within a similar group (e.g., estuarine/marine fish).Page 81 of 103 Table 22: Avian Acute-Oral Toxicity

Test Species Test Material (% ai) Toxicity Toxicity Category EPA Study
ID

Northern bobwhite ( Colinus virginianus ) 100 LD50 = 0.24 mg ai/kg
bw Very highly toxic 470013023 Acceptable

Not reported LD50 = 492 mg ai/kg
bw Moderately toxic 97534 Acceptable

23.5 LD50 = 500 mg ai/kg
bw Moderately toxic 106859 Supplemental

22 LD50 = 681 mg ai/kg
bw Slightly toxic 134550 Supplemental

Mallard ( Anas platyrhynchos) 22 LD50 = 3200 mg ai/kg
bw Practically nontoxic 110384 Supplemental

Eight available dietary (LC50) studies categorize the AMTDs as being practically nontoxic to slightly toxic birds when administered in the diet (Table 23). No additional data are needed for this guideline (850.2200).

Table 23: Avian Dietary Toxicity

Test Species Test Material (% ai) Toxicity Toxicity Category EPA Study
ID

Northern bobwhite ( Colinus virginianus ) 100 LC50 = 6400 ppm Practically
nontoxic 470013024 Acceptable

32 LC50 = 6400 ppm Practically
nontoxic 40062405 Acceptable

0.03 LC50 >10,000 ppm Practically
nontoxic 123864 Acceptable

Not reported LC50 = 5000 ppm Practically
nontoxic 97535 Supplemental

Mallard ( Anas platyrhynchos ) 50 LC50= 5000 ppm Slightly nontoxic 133266 Acceptable

0.03 LC50 = 100,000 ppm Practically
nontoxic 123863 Acceptable

32 LC50= 6400 ppm Practically
nontoxic 470013025 Supplemental

Not reported LC50 = 5000 ppm Practically
nontoxic 97516 SupplementalPage 82 of 103 Nontarget Insects Toxicity data for benefi cial insects (850.3020, 850.3030) are not required for this use pattern.



### Toxicity to Aquatic Organisms

Freshwater Fish The available acute toxicity studies categor ize the AMTDs as being slightly to highly toxic to freshwater fish (Tab le 24). The guideline (850.1075) fo r acute toxicity testing is
satisfied.

Table 24: Freshwater Fish Acute Toxicity

Test Species Test Material (% ai) Toxicity Endpoint (mg ai/L) Toxicity Category EPA Study ID

Rainbow Trout ( Oncorhynchus mykiss) 32 96-hr LC50 = 0.12 Highly toxic 41786606 Acceptable

0.03 96-hr LC50 = 1300 Slightly toxic 123862 Acceptable

Not reported 96-hr LC50 = 1.58 Moderately
toxic 97518 Supplemental Bluegill ( Lepomis macrochirus ) 50 96-hr LC50 = 0.3 Highly toxic 133265 Acceptable

32 96-hr LC50 = 0.96 Highly toxic 41786601 Acceptable

32 96-hr LC50 = 0.3 Highly toxic 41786601 Supplemental

0.03 96-hr LC50 = 1390 Practically
nontoxic 123862 Acceptable

Chronic data are available for the fathead minnow. Based on the ACR for the fathead minnow (acute toxicity predicted from Web-ICE, EPA 2013) and the acute toxicity value for the rainbow trout, the most acutely sensitive fres hwater fish species, an NOAEC value of 0.004 mg ai/L was determined for the rainbow trout. No additio nal chronic data are needed (fish early-life stage, 850.1400).Page 83 of 103 Table 25: Freshwater Fish Chronic Toxicity

Test Species Test Material (% ai) NOAEC (mg ai/L) LOAEC (mg ai/L) EPA Study ID

Fathead minnow ( Pimephales promelas ) 94.1 0.011 0.023 49040209 Acceptable

Rainbow Trout ( Oncorhynchus mykiss) NA 0.004 a nd 49208804 Acceptable

a The rainbow trout was the most acutely sensitive fish species tested but no chronic data are available for this species; therefore, a chronic NOAEC was estimated for th e trout. The chronic value was extrapolated using an acute-chronic ratio (ACR; EPA 2010) of 29 as determined by using the fathead minnow LC50 (328 μg ai/L as predicted from Web-ICE; EPA 2013, see Appendix C), fathead minnow NOAEC (11 μg ai/L), and the rainbow trout LC50 (120 μg ai/L)

Freshwater Invertebrates

The four available acute toxicity studies fo r the waterflea categorize the AMTDs as being highly to very highly toxic to freshwater invertebrates (Table 26). One chronic study found no adverse effects on daphnid reproduction or growth but mortality occurred at 0.016 mg ai/L. The guidelines for acute (850.1010) and chronic ( 850.1300) toxicity tes ting are satisfied.

Table 26: Freshwater Invertebrates Acute and Chronic Toxicity

Test Species Test Material (% ai) Toxicity Endpoint (mg ai/L) Toxicity Category EPA Study
ID

Waterflea ( Daphnia

magna ) 32 48-hr EC50 = 0.051 Very highly toxic 41786602 Acceptable

32 48-h EC50 = 0.16 Highly toxic 41786602 Acceptable

32 48-h EC50 = 0.104 Highly toxic 40062409 Acceptable

Not reported 48-h EC50 = 0.12 Highly toxic 97521 Supplemental

94.1 Chronic NOAEC = 0.016
Chronic LOAEC = 0.054 NA 490402-08 AcceptablePage 84 of 103 Estuarine/Marine Fish and Invertebrates

The available estuarine/marine acute toxicity studies categorize AMTD as being highly to very highly toxic to fish and pr actically nontoxic to very highly t oxic to invertebrates (Table 27). The guidelines for acute testing with a fi sh (850.1075), a bivalve (850.1025 or 850.1055), and one additional invertebrate (850.1035) are satisfie d. Chronic data were not submitted, but ACRs were used to extrapolate chronic NOAECs for fish and crustaceans. The predicted NOAECs indicate that chronic effects may occur at ATMD concentrations in the parts per billion (Table 27). Additional chronic data (850.1300) are not needed.

Table 27: Estuarine/Marine Invert ebrates Acute and Chronic Toxicity

Test Species Test Material (% ai) Toxicity Endpoint (mg ai/L) Toxicity Category EPA Study
ID

Atlantic silverside (Menidia menidia) 32 96-hr EC50 = 0.155 Highly toxic 41786604 Acceptable

32 48-h EC50 = 0.577 Highly toxic 41786604 Acceptable

NA Chronic NOAEC = 0.005 a NA NA

Mysid shrimp ( Mysidopsis bahia ) 32 96-h EC50 = 0.019 Very highly toxic 41786605 Acceptable

NA Chronic NOAEC = 0.019 b NA NA

Quahog clam ( Mercenaria mercenaria ) 32 48-h EC50 = 0.019 Very highly toxic 41786603 Acceptable White shrimp ( Penaeus setiferus ) 32 96-h EC50 = 2.39 Moderately toxic 40062411 Supplemental

Eastern oyster ( Crassostrea virginica ) 32 96-h EC50 = 720 Practically nontoxic 40062412 Acceptable Pink shrimp ( Penaeus duorarum ) 0.03 96-h EC50 = 1000 Practically nontoxic 123866 Acceptable

Fiddler crab ( Uca pugilator ) 0.03 96-h EC50 = 1000 Practically nontoxic 123866 AcceptablePage 85 of 103 Test Species Test Material (% ai) Toxicity Endpoint (mg ai/L) Toxicity Category EPA Study
ID

Blue crab ( Callinectes trimethylenedi ) Not reported 96-h EC50 = 387 Practically nontoxic 97520 Supplemental

a The NOAEC is extrapolated from the ACR (29) for freshwater fish (see footnote a) and LC50 of 155 μg ai/L for the Atlantic silverside; the extrapolation assumes a common chronic mode of action for freshwater and
estuarine/marine fish

b The NOAEC is extrapolated from the ACR (3) for freshwater invertebrates (LC50 = 51 μg ai/L, NOAEC = 16 μg ai/L) and the acute toxicity for the estuarine/marine crustac ean (mysid shrimp LC50 = 61 μg ai/L); the extrapolation
assumes a common chronic mode of action for fr eshwater and estuarine/marine invertebrates

Aquatic Plants

Aquatic plant toxicity data are presented in Table 28. Studies available for the TGAI include a toxicity test with duckweed, a vascular species (85 0.4400), and algal toxicity tests (850.4500) with green algae (2 spp. ), a freshwater diatom, and a marine diatom. Web-ICE was used to predict the toxicity of cyanobacteria (850.4550). No additional testing is needed.

Table 28: Aquatic Plant Toxicity

Test Species Test Material (% ai) Toxicity Endpoint (mg ai/L) EPA Study
ID

Duckweed ( Lemna gibba ) 94.1 7-d EC50 = 0.123
NOAEC = 0.020 49040213 Acceptable Green algae ( Pseudokirchneriella subcapitata) 94.1 96-h EC50 = 0.0052
NOAEC = 0.0024 49040216 Acceptable Green algae ( Scenedesmus subspicatus) 94.1 96-h EC50 = 0.011
NOAEC = 0.0069 49040217 Acceptable

Freshwater diatom (Navicula pelliculosa) 94.1 96-h EC50 = 0.017
NOAEC = 0.009 49040215 Acceptable

Marine Diatom ( Skeletonema costatum ) 94.1 96-h EC50 = 0.011
NOAEC = 0.008 49040214 Acceptable
Cyanobacteria ( Anabaena flos-aquae ) -- 96-h EC50 = 0.007 a 49208807 Supplemental

a predicted from the Web-ICE Algae Module (EPA 2013) using Pseudokirchneriella subcapitata as a surrogate species

Subchronic sediment toxicity

Two subchronic studies are available (Table 29). One study tested the freshwater midge (850.1735) and another study tested the estuarin e/marine amphipod (850.1740). A data gap
exists for a subchronic test fo r the freshwater amphipod (850.1735). Lack of toxicity for thePage 86 of 103 second freshwater species adds uncertainty to the risk assessment fo r freshwater benthic
invertebrates.

Table 29: Subchronic Sediment Toxicity

Test Species Test Material (% ai) Toxicity Endpoint (mg ai/kg sediment) EPA Study
ID
Freshwater Midge ( Chironomus tentans ) 94.1 10-d EC50 = 188
NOAEC = 16 49040211 Acceptable Marine Amphipod ( L eptocheirus plumulosus ) 94.1 10-d EC50 = 303
NOAEC = 174 49040212 Acceptable

Ecotoxicity References

EPA. 2013. Web-based Interspecies Correla tion Estimation (Web-ICE) for Acute Toxicity: User Manual (version 3.2). EP A/600/R-12/603. USEPA Office of Research and Development, Gulf Ecology Division, Gulf Breeze, FL http://www.epa.gov/ceampubl/fchain/webice/

EPA. 2010. Predicting the Toxic ities of Chemicals to Aquatic Animal Species. USEPA Office of Water and Office of Pesticide Programs, Washington, DC; Office of Research and Development, Gulf Ecology Division; and Office of Research and Development, Mid-Continent Ecology Division. October 27, 2010.

MRID 41786602 Surprenant, D. 1988. Acute T oxicity of Microbiocide 56 to Daphnids ( Daphnia

magna ): Lab Project Number: 88-3-2669: 384.1187.6100.110. Unpublished study prepared by Springborn Life Sciences, Inc. 20p.

MRID 41786603 . Surprenant, D. 1988. Acute Toxicity of Microbiocide 56 to Embryo-Larvae of the Quahog Clam ( Mercenaria mercenaria ) Under Static Renewal Conditions: Lab Project Number: 88-5- 2712. Unpublished study prepared by Springborn Life Sciences, Inc. 20p.

MRID 41786604 Surprenant, D. 1988. Acute Toxicity of Microbiocide 56 to Silversides ( Menidia menidia ) Under Static Renewal Conditions: Lab Pr oject Number: 88-4-2687: 384.1187.6100.501. Unpublished study prepared by Sprin gborn Life Sciences, Inc. 19p.

MRID 41786605.Surprenant, D. 1988. Acute Toxicity of Microbiocide 56 to Mysid Shrimp ( Mysidopsis bahia ): Lab Project Number: 88-4-2739: 384.1187.6100.510. Unpublished study prepared by Springborn Life Sciences, Inc. 20p.

MRID 41786606 Surprenant, D. 1990. Acute Toxi city of Microbiocide 56 to Rainbow Trout ( Salmo gairdneri ) Under Static Conditions: Lab Project Number: 88-11-2861: 384.0788.6101.103. Unpublished study prepared by Sprin gborn Life Sciences, Inc. 19p.

MRID 40062404. Bisinger, E. (1984) Avian Oral LD50 in Bobwhite Quail: Wildlife and Aquatic Organism Data Requirements: Armohib B-101: Re port No. T-4000: [Supplemental Data Submitted in Response to EPA’s Comments]. Unpublished study pr epared by Akzo Chemie America and Product Safety Labs. 14p.Page 87 of 103 MRID 40062405. Bisinger, E. (1984) Avian Dietar y LC50 in Bobwhite Quail: Wildlife and Aquatic Organism Data Requirements: Armohib B-101: Re port No. T-3995: [Supplemental Data Submitted in Response to EPA’s Comments]. Unpublished study pr epared by Akzo Chemie America and Product Safety Labs. 13p.

MRID 40062609. Bisinger, E. (1984) Acute LC50: Daphnia magna: Wildlife and Aquatic Organism Data Requirements: Armohib B-101: Report No. H- 8241: [Supplemental Data Submitted in Response to EPA’s Comments]. Unpublished study prepared by Ak zo Chemie America and MBA Laboratories. 14p.

MRID 40062411. Bisinger, E. (1984) Acute LC50 in Estuarine and Marine Organisms/96-hour LC50 in White Shrimp: Wildlife and Aquatic Organism Data Requirements: Armohib B-101: Report No. H-8241: [Supplemental Data Submitted in Response to EPA’s Comments]. Unpublished study prepared by Akzo Chemie America and MBA Laboratories. 14p.

MRID 40062412. Bisinger, E. (1984) Acute LC50 in Estuarine and Marine Organisms/96-hour LC50 in Oyster: Wildlife and Aquatic Or ganism Data Requirements: Armo hib B-101: Report No. H-8241: [Supplemental Data Submitted in Response to EPA’s Comments]. Unpublished study prepared by Akzo Chemie America and MBA Laboratories. 14p.

MRID 49040208 Minderhout, T. et al. 2012. DUOMEEN C: A Flow-through Life-cycle Toxicity Test with the Cladoceran ( Daphnia magna ). Wildlife International, Ltd. Project No.: 709A-108A. Mexel Industries, SAS: C/O Mexel USA, LLC.

MRID 49040209 Minderhout, T., K. et al. 2012. DUOMEEN C: An Early Life-Stage Toxicity Test with the Fathead Minnow ( Pimephales promelas ). Wildlife International, Ltd. Project No.: 709A-109A. Mexel Industries, SAS: C/O Mexel USA, LLC.

MRID 49040211 Thomas, S. et al. 2013. DUOMEEN C: A 10-day Survival and Growth Toxicity Test with the Midge ( Chironomus tentans ) Using Spiked Sediment. Wildlife International, Ltd. Project No: 709A-106. Study sponsored by Mexel Industries, SAS C/O Mexel USA, LLC.

MRID 49040212 Thomas, S. et al. 2013. DUOMEEN C: A 10-day Survival Test with the Marine Amphipod (L eptocheirus plumulosus ) Using Spiked Sediment. Wildlife International, Ltd. Project No: 709A-107A. Study sponsored by Mexel Industries, SAS C/O Mexel USA, LLC.

MRID 49040213 Jacobs, A. et al. 2012. DUOMEEN C: A 7-Day Static-Renewal Toxicity Test with Duckweed ( Lemna gibba G3). Wildlife International, Ltd. Project No: 709A-101. Study sponsored by Mexel Industries, SAS C/O Mexel USA, LLC.

MRID 49040214 Jacobs, A. et al. 2012. DUOMEEN C: A 96-hour Toxicity Test with the Marine Diatom ( Skeletonema costatum ). Wildlife International, Ltd. Pr oject No: 709A-104. Study sponsored by Mexel Industries, SAS C/O Mexel USA, LLC.

MRID 490402-15 Jacobs A. et al. 2012. DUOMEEN C: A 96-hour Toxicity Test with the Freshwater Diatom ( Navicula pelliculosa ). Wildlife International, Ltd. Project No: 709A-105. Study sponsored by Mexel Industries, SAS C/O Mexel USA, LLC.Page 88 of 103 MRID 49040216 Jacobs, A. et al. 2012. DUOMEEN C: A 96-hour Toxicity Test with the Freshwater Alga ( Pseudokirchneriella subcapitata ). Wildlife International, Ltd. Project No: 709A-102. Study sponsored by Mexel Industries, SAS C/O Mexel USA, LLC.

MRID 49040217 Jacobs, A. et al. 2012. DUOMEEN C: A 96-hour Toxicity Test with the Freshwater Alga ( Scenedesmus subspicatus ). Wildlife International, Ltd. Pr oject No: 709A-103. Study sponsored by Mexel Industries, SAS C/O Mexel USA, LLC.

97516. Casterton, P.L. (1979) Avian Dietary LC50 (Mallard Duck): Laboratory Report No. K-5096. (Unpublished study received Jun 16, 1980 under 38231 -2; prepared by Microbiological and Biochemical Assay Laboratories, submitted by C-E Natco, Tulsa, Okla.; CDL: 242696-A)

97518. Reed, D. (1979) Laboratory Test Report: St atic LC50: Rainbow Trout: Laboratory Report No. K5096. (Unpublished study received Jun 16, 1980 under 38231-2; prepared by Microbiological and Biochemical Assay Laboratories, submitted by C-E Natco, Tulsa, Okla.; CDL: 242698-A)

97519. Casterton, P.L. (1979) Fish Acute LC 50 (Redear Sunfish): Laboratory Report No. K-5096. (Unpublished study received Jun 16, 1980 under 38231 -2; prepared by Microbiological and Biochemical Assay Laboratories, submitted by C-E Natco, Tulsa, Okla.; CDL: 242699-B)

97520. Casterton, P.L. (1979) Laboratory Test Re port: (Static LC50: Blue Crab): Laboratory Report No. K-5096. (Unpublished study received Jun 16, 1980 u nder 38231-2; prepared by Microbiological and Biochemical Assay Laboratories, submitted by C-E Natco, Tulsa, Okla.; CDL: 242699-A)

97521. Kresse, H.J. (1980) Daphnia magna : Acute LC50: Laboratory Report No. K-5096. (Unpublished study received Jun 16, 1980 under 38231-2; prep ared by Microbiological and Biochemical Assay Laboratories, submitted by C-E Natc o, Tulsa, Okla.; CDL: 242698-B)

97534. Casterton, P.L. (1979) Avian Acute Oral LD50: Bobwhite Quail: Laboratory Report No. K-5096. (Unpublished study received Jun 16, 1980 under 38231 -2; prepared by Microbiological and Biochemical Assay Laboratories, submitted by C-E Natco, Tulsa, Okla.; CDL: 242695-A)

97535. Casterton, P.L. (1979) Avian Dietary LC50 (Bobwhite Quail): Laboratory Report No. K-5096. (Unpublished study received Jun 16, 1980 under 38231 -2; prepared by Microbiological and Biochemical Assay Laboratories, submitted by C-E Natco, Tulsa, Okla.; CDL: 242695-B)

106859. Fletcher, D. (1973) Report to Nalco Chemical Company: Acute Oral Toxicity Study with 32D16 in Bobwhite Quail: IBT No. 65 1-02892. Unpublished study receive d Apr 9, 1973 under 1706-126; prepared by Industrial Bio-Test Laboratories, In c., submitted by Nalco Chemical Co., Oak Brook, IL; CDL: 051060-D)

110384. Fletcher, D. (1973) Report to Nalco Chemical Company: Acute Oral Toxicity Study with 32D16 in Mallard Ducks: IBT No. 651-02893. Unpublis hed study received Apr 9, 1973 under 1706-126; prepared by Industrial Bio-Test Laboratories, In c., submitted by Nalco Chemical Co., Oak Brook, IL; CDL: 051060-C)Page 89 of 103 123862. Bentley, R. (1975) Acute Toxicity of Co-op Turbex to Lepomis macrochirus and Salmo gairdneri . (Unpublished study received Mar 5, 1975 un der 1990-372; prepared by Bionomics, EG&G Environmental Consultants; submitted by Farmland Industries, Inc., Kansas City, MO; CDL: 110678-A)

123863. WARF Institute, Inc. (1975) Report: WARF Institute No. 4112599. (Un published study received Mar 5, 1975 under 1990-372; submitted by Farmland Industries, In c., Kansas City, MO; CDL: 110680-A)

123864. WARF Institute, Inc. (1975) Report: WARF Institute No. 4112599. (U npublished study received Mar 5, 1975 under 1990-372; submitted by Farmland Industries, In c., Kansas City, MO; CDL: 110680-B)

123866. Heitmuller, T. (1975) Acute Toxicity of Surflo-B15 to Larvae of the Eastern Oyster ( Crassostrea virginica ), Pink Shrimp ( Penaeus duorarum ), and Fiddler Crab ( Uca pugilator ). (Unpublished study received Jun 1, 1975 under 1 7664-11; prepared by Bionomics—EG&G, Inc., submitted by Baroid Div., N.L. Industri es, Inc., Houston, TX; CDL: 165021-A)

133265. Thompson, C.; McAllister, W. (1983) Acute T oxicity of EH&S 266 to Bluegill Sunfish: Static Bioassay Report 30595. (Unpublished study receive d Oct 25, 1983 under 10349-14; prepared by Analytical Biochemistry Laboratories, Inc., submitted by Visco, Div. of Nalco Chemical Co., Sugar Land, TX; CDL: 251787-A)

133266. Beavers, J.; Jaber, M.; Joiner, G.; et al . (1983) A Dietary LC50 in the Mallard with EH&S 267: Project No. 187-103. Final Repor t. (Unpublished study received Oc t 25, 1983 under 10349-14; prepared by Wildlife International, Ltd., submitted by Visco, Div. of Nalco Chemical Co., Sugar Land, TX; CDL: 251788-A)

134550. Fletcher, D. (1972) Report to Esso Research and Engineering Company: Acute Oral Toxicity Study with MRD 72-10 in Bobwhite Quail: IBT No . J1739. (Unpublished stud y received Jul 25, 1972 under 8928-4; prepared by Industrial Bio-Test La boratories, Inc., submitted by Exxon Chemical Americas, Houston, TX; CDL: 005650-D)

470013023. Shapiro, R. (1984) Avian Single Do se LD50 – Bob White Quail: [Armohib B-101]: Report No. T-4000. Unpublished study prep ared by Product Safety Labs. 14p.

470013024. Shapiro, R. (1984) Avian Dietary LC 50 Study with Bob White Quail: Armohib B-101: Report No. T-3995. Unpublished study pr epared by Product Safety Labs. 6p.

470013025. Shapiro, R. (1984) Avian Dietary LC50 Study with Mallard Ducks: Armohib B-101: Report No. T-3998. Unpublished study prep ared by Product Safety Labs. 11p.Page 90 of 103 

### Whole Effluent Toxicity Testing

Calvert Cliffs Nuclear Power Plant (CCNPP) Whole Effluent Toxicity Testing

Mexel was applied to CCNPP, Lusby, Ma ryland, cooling water during a trial by the facility to examine the effec tiveness of the product. During this Mexel trial the Maryland Department of Environment requir ed whole effluent toxicity tes ting with two estuarine species, Inland silverside ( Menidia beryllina ) and mysid ( Americamysis bahia ) (Richardson, 2011 in MRID 49208816). Results of the short-term chr onic whole effluent toxicity tests of CCNPP cooling water effluent were submitted by the registrant to help characterize the toxicity and risk in cooling water systems of Mexel (MRID 49208816).

CCNPP has two generator units which share th e same cooling water intake structure and outfall. CCNPP has a once through cooling system with a design flow of 1.2 million gallons per minute per generator unit (total of 2.4 million gallons per minute or 3460 million gallons per day) (U.S.NRC 1999). Bay water enters an intake channel, and transits through the plant in approximately 4 minutes (U.S.NRC 1999). Outfall 01 is offshore in 3 meters (10 feet) of water and the cooling water effluent is discharged at high velocity (2.7 me ters per sec) which results in rapid mixing; the specific effluent sampling loca tion within Outfall 01 area was not described.

The short-term chronic toxicity of Calver t Cliffs Nuclear Power Plant (CCNPP), Lusby, Maryland, cooling water treated w ith Mexel 432 and discharged at Outfall 01 in May, July, and September 2011 to Inland silverside ( Menidia beryllina ) was studied under effluent static renewal conditions. Three studies, one in May, July and September were conducted using juvenile Inland silverside, 9-10 days old. Four studies, one in May, June, July, and September were conducted using 7-8 day old mysids. In each study organisms were exposed to 100, 50, 25, 12.5, and 6.25% effluent and a laboratory dilution water control for seven days. For Inland silverside and mysids the test systems were maintained at 25 + 1 o C and 26 + 1 o C, respectively, and a salinity of 20 + 0.5 ppt. The Mexel dosing regime of the cooling water system was not reported for June or July. The cooling wate r dosing regimes provided for May and September differed. In May cooling water at the facility wa s not dosed with Mexel on the day effluent was collected for use in preparing test solutions fo r use in the last three test days, whereas in September cooling water at the facility was not dosed with Mexel on the day effluent was collected for use in preparing test solutions for th e first two test days. On days Mexel was used, it was applied for 30 minutes at nominal con centrations of 3.3 pp m Mexel (0.056 ppm ATMD) to obtain 2.5 ppm Mexel (0.042 ppm ATMD) residual in the cooling water.

Results of the studies are summarized in Ta ble 30. For Inland silverside the 7-day NOAEC values for survival, for May, July, and Se ptember effluent were all 100% effluent and were 50%, 100%, and 100%, respectively, for grow th (measured as mean body weight (dry)).Page 91 of 103 There was no mortality in 100% May, July and September effluent. Other than growth, no observations on other sublethal morphology or beha vior were observed. The most sensitive end point was

Two of the mysid studies had higher than guideline standards for an acceptable study, and these results are classified as unacceptable for use in characterizing whole effluent toxicity. The remaining tests are classified as supplem ental information. The reports provided for documentation are draft, not finalized documents. While the studies as presented in the drafts appear to be scientifically sound studies for the specific facility and its treatment regime, critical primary study design information was missing from the package provided which would allow the study results to bridge to use in other cooli ng water systems, and the highest allowed label application regime. Specifical ly, unknown timing between dosing of cooling water system and collection of effluent, the lack of dosing the c ooling water system with Mexel on all effluent collection days which is assumed to mean no ATMD would be present in effluent, and the lack of dosing information for some dates (e.g., all of June, July) during the effluent collection period. Additionally, no analytical meas urements were made on ATMD levels present in the 100% effluent. While such analytical information wa s not necessary for the purpose of the study, to bridge to other water cooling systems such inform ation is critical. How a user would determine
residual Mexel at a site is not on the label.

Table 30: Summary of Whole Effluent Toxi city Test Results for CCNPP in 2011 during Mexel Treatment Trial

Endpoint Inland Silverside Results Mysid Results D May A July B September C June B September C
48-hr LC 50 >100% >100% >100% >100% >100% 96-hr LC 50 >100% >100% >100% >100% >100% 7-day NOAEC 50% 100% 100% >100% >100%

Most sensitive endpoint body weight E survival, body weight E survival, body weight E survival, body weight E

, fecundity survival, body weight E

, fecundity

A Cooling water at the facility was not dosed with Mexel on the day effluent was collected for use in preparing test solutions for the last three test days.

B Cooling water dosing with Mexel is unknown.

C Cooling water at the facility was not dosed with Mexel on the first day effluent was collected for use in preparing test solutions for the first two test days.

D May and July results were classified as unacceptabl e because control mortality was greater than guideline standards for an acceptable, sc ientifically sound study.

E For each replicate the reviewer used mean dry weight (dw) per surviving fish to evaluate growth effects whereas study authors used total dw divided by initial number of exposed organisms to evaluate “mean biomass”.Page 92 of 103 Donald C. Cook Nuclear Power Plant (DCCNPP) Whole Effluent Toxicity Testing

Mexel was applied to DCCNPP, Bridgman, Michigan, cooling water during a trial and on-site research by the facility to examine the effectiveness of the product. During this Mexel trial whole effluent acute toxicity testing with two freshwater species, Fathead minnow ( Pimephales promelas ) and the waterflea ( Daphnia magna ) were conducted. Results of the acute whole effluent toxicity tests of DCCNPP cooling water effluent were submitted by the registrant to help characterize the toxici ty and risk in cooling water systems of Mexel (MRID 49208816). A Tier I ambient water quality final acute value for DCCNPP was set by the State of Michigan as 0.1 ppm Mexel. No chronic criteria value was id entified in the documenta tion for this facility.

DCCNPP has a once through cooling system with a design flow of 1.645 million gallons per minute (MGM) for the condenser cooling wa ter flow, 0.16 MGM for the essential service water, and 0.009 MGM for the nonessential serv ice water system, for a total intake of approximately 1.67 MGM (2405 million gallons per da y). The total cooling water transit time from intake to discharge is about ten minutes. DCCNPP has high veloci ty discharge diffusers
with a 3:1 dilution credit for a mixing zone in Lake Michigan.

Three types of effluent samples were tested for each species:

 A 24-h composite effluent sample where gr ab samples were collected once every hour using an automatic composite sampler and wher e the last sample was collected during the 30 minute Mexel treatment;

 An effluent grab sample from the 30 minute Mexel dosing period in the previous bullet; and

 Lake water dosed with Mexel from a pilot te st rig mixed with two gallons of untreated lake water to simula te a 3:1 dilution.

Dosing of Mexel during the 30 minute dosing of DCCNPP cooling water and lake water in the pilot test rig was at 4 ppm (0.068 ppm ATMD) which was reported to result in a 2.5 ppm Mexel (0.0425 ppm ATMD) residual (GLEC 2006, 2007). Sample collection for the 24-hour composite started the morning of November 29, 2006. Sample collection continued for 24-hours with the last sample collect ed the next day, November 30, 2006, during the 30-minute Mexel treatment period. Sample collection for the gr ab sample during the 30-minute Mexel treatment occurred on November 30, 2006. The cooling wate r from the test rig was collected August 28,
2007.

The D. magna tests were conducted as static ex posure tests using <24 hour old organisms. The fathead minnow tests were cond ucted as static renewal exposure tests, with renewal at 48 hours; however the effluent was from the same effluent sample and not a new effluent sample (GLEC 2006, 2007). In each st udy organisms were exposed to 100, 50, 25, 12.5,Page 93 of 103 and 6.25% effluent and a Lake Michigan dilu tion water control. For fathead minnows and D.

magna the test systems were maintained at 25 + 1 o C (GLEC 2006, 2007).

Results of the studies are su mmarized in Table 31. For both D. magna and the fathead minnow the 24-h composite efflue nt acute toxicity was >100% effluent and there was no mortality in 100% effluent. Effluent collected during the 30 minute Mexel dosing period had acute toxicity. It was estimated from these results that for the f acility, a 3:1 dilution which is the edge of the credited mixing zone dilution would be sufficient to m eet the Tier I final acute value
SPDES limit. A Tier I final acu te criterion of 0.1 ppm Mexel was set for the edge of the credited mixing zone. The cooling water treated with Mexel from the pilot rig and diluted 3:1 was acutely toxic to both D. magna and fathead minnow.

Table 31: Summary of Whole Effluent Toxi city Test Results for DCCNPP in 2006 and 2007 during Mexel Treatment Trial

Cooling Water Effluent Sample Type D. magna 48-h EC 50 Results Fathead minnow 96-h LC 50 Results

% Effluent Nominal Residual

Mexel Nominal ATMD % Effluent Nominal Residual

Mexel Nominal ATMD
24-h Composite (11/29,30/2006) >100 >2.5 ppm A 0.0425 ppm A >100 >2.5 ppm A 0.0425 ppm A

Grab Sample (11/30/2006) 35.4 0.88 ppm A 0.015 ppm A 27.7 0.69 ppm A 0.012 ppm A

Pilot Rig 3:1 (08/28/2007) 65.9 0.41 ppm B 0.007 ppm B 66 0.41 ppm B 0.007 ppm B

A Assuming 2.5 ppm Mexel (0.0425 ppm ATMD) residual in 100% effluent. The actual ATMD in 100% effluent
was not measured.

B Assumes the 3:1 dilution contains 0.625 ppm Mexel residual (0.0106 ppm ATMD) which is equivalent to 2.5 ppm Mexel (0.0425 ppm ATMD) residual target diluted 3:1. The actual ATMD in the 3:1 dilution was not measured.

The tests are classified as supplemental in formation. While the studies appear to be scientifically sound for the specific facility and its treatment regime, critical information that would allow bridging to other co oling water systems, and the highest allowed label application regime. No analytical measurements were made on ATMD levels presen t in the 100% effluent
and how residual is determined is not defined. While such analytical information was not necessary for the purpose of the study, to bridge to other water cooling systems such information
is critical. How a user would determine re sidual Mexel at a site is not on the label.



### Whole Effluent Toxicity Study References

Richardson, M. 2011. Correspondence from M. Richardson, Chief, Industrial and General Permits Division, Maryland Department of Environment to B. Nuse, SeniorPage 94 of 103 Environmental Specialist, Calvert Cliffs Nuclear, Power Plant, LLC re: Use of Mexel anti -fouling treatment in discharge for Stat e Discharge Permit No.: 08-DP-0187, NPDES Permit No.: MD0002399 (copy in MRID 49208816).

United States Nuclear Regulat ory Commission (U.S.NRC). 1999. Generic Environmental Impact Statement for License Renewal of Nuclear Plants: Regarding Calvert Cliffs Nuclear Power Plant – Final Report ( NUREG-1437, Supplement 1). Division of Regulatory Improvement Programs, Office of Nuclear Reactor Regulation, Washington,
D.C. October. http://www.nrc.gov/reading-rm/doccollections/nuregs/staff/sr1437/supplement1/#_1_2

Great Lakes Environmental Cent er (GLEC). 2006. Acute toxici ty test reports for samples collected from American Electric Power, Cook Nuclear Power Plant on November 29/30, 2006 in U.S.NRC Appendix V, Special Reports 2008. http://pbadupws.nrc.gov/docs/ML0913/ML091340525.pdf

Great Lakes Environmental Cent er (GLEC). 2007. Acute toxici ty test reports for samples collected from American Electric Power, Cook Nuclear Power Plant on August 28, 2007 in U.S.NRC Appendix V, Special Reports 2008. http://pbadupws.nrc.gov/docs/ML0913/ML091340525.pdfPage 95 of 103 

### APPENDIX D: RISK ESTIMATION METHODS

Risk estimation integrates the results of the exposure and ecotoxicity data to evaluate the likelihood of adverse ecological eff ects. There are generally two approaches used in assessing risks from industrial process and water systems, a risk quotient (RQ) me thod and a probabilistic
method.

Risk Quotient (RQ) Method

In the RQ method, estimates of exposure are divided by ecotoxicity endpoint values. These RQs are then compared to presumptive levels of concern (LOCs) to identify potential risk to nontarget organisms and the need to consider regulatory action. These LOCs are standards used by the EPA to indicate pote ntial risk to non-target organi sms and the need to consider regulatory action; the development of these LO Cs is discussed in detail in the Agency’s
Overview Document 42 . Types of RQs (e.g., acute vers us chronic), RQ equations, and corresponding LOCs and risk presum ptions are tabulated in Table 32.

Table 32 Risk Presumption Categories

Risk Presumption for Terrestrial Animals RQ LOC

Acute: Presumption of high acute risk for nontarget animals EEC A /LC 50 or EEC B /LD 50 > 0.5 Acute Restricted Use: Presumption of acute risk for nontarget animals, but potentially may be mitigated through restricted use EEC A /LC 50 or EEC B /LD 50 > 0.1
Acute Endangered Species: Endangered species may be affected acutely EEC A /LC 50 or EEC B /LD 50 > 0.05 Chronic Risk: Presumption of chronic risk to nontarget animals, endangered species may be affected chronically EEC A /NOAEC > 1.0

Risk Presumption for Aquatic Animals RQ LOC

Acute: Presumption of high acute risk for nontarget animals EEC C /LC 50 or EEC C /EC 50 or EEC C /IC 50 > 0.5

Acute Restricted Use: Presum p tion of acute ris k for nontar g et animals, EEC C /LC 50 or EEC C /EC 50 or > 0.1 Acute Endangered Species: Endangered species may be affected acutely EEC C /LC 50 or EEC C /EC 50 or C > 0.05

Chronic Risk: Presumption of chronic risk to nontarget animals, endangered species may be affected chronically Water: EEC C /NOAEC > 1.0

Sediment: EEC D /NOAEC >1.0
Risk Presumption for Aquatic Plants RQ LOC

Non-Endangered Species: Presumption of high risk to all nontarget aquatic plants EEC C /IC 50 > 1.0

Endangered Species: Endangered plants may be affected EEC C /NOAEC or EEC C /IC 05 E > 1.0
Risk Presumption for Terrestrial Plants RQ LOC Non-Endangered Species: Presumption of high risk to all nontarget

p lants EEC C /IC 25 > 1.0

Endangered Species: Presumption of high risk to all nontarget aquatic plants EEC C /NOAEC or EEC C /IC 05 E > 1.0

42 http://www.epa.gov/espp/consultation/ecorisk-overview.pdfPage 96 of 103 A Dietary exposure in parts per million (ppm) of the pesticide in/on dietary items.

B Dietary exposure dose in mg/kg-bw/day.

C Concentration in water in parts per million (ppm).

D Concentration in mg/kg-sediment.

E An IC 05 can be used in lieu of an NOAEC, if one cannot be determined or if it is above the IC 25 .

Probabilistic Method

For use patterns that result in antimicrobial s entering surface wate r by way of industrial wastewater treatment plants or direct discharge from the industri al site without treatment, the Agency relies upon estimating loadings of antimic robials to industrial wastewater treatment plants and using the General P opulation Exposures from Industria l Releases module of E-FAST to estimate number of days of exceedance of concentrations of concern (COCs) for aquatic organisms. COCs for acute effects on non-liste d aquatic vertebrates and invertebrates were determined by dividing LC 50 (or EC 50 ) values from acute toxicity te sts on aquatic vertebrates and invertebrates, respectively, by 2. COCs for chr onic effects for non-listed aquatic vertebrate and invertebrate species were base d on chronic NOAEC values from te sts on aquatic vertebrates and invertebrates, respectively. Acute COCs for liste d endangered and threatened aquatic vertebrates
and invertebrates were dete rmined by dividing acute LC 50 (or EC 50 ) values from acute toxicity tests on aquatic vertebrates and invertebrates, respectively, by 20. COCs for nonlisted aquatic vascular plants and algae are based on IC 50 values. COCs for enda ngered algae and aquatic vascular plants are ba sed on NOAEC values.

Based on probabilistic modeling results, if the acute COC (one-half of theLC 50 or EC 50 ) determined for any key aquatic receptor group is exceeded for one day or more based on results from the high-end scenario (i.e., the 10 th percentile of the ratio of 7Q10 (i.e., lowest 7 consecutive-day stream flow over a 10-year period ) stream flows to plant flows), then potential acute risks to such receptor groups are indicated. In additi on, if the endangered COC (onetwentieth of the LC 50 or EC 50 ) determined for any key aquatic receptor group is exceeded for one day or more based on result s from the high-end scenario, th en potential acute risks to endangered aquatic organisms in such receptor groups are indicated. Furthermore, if the chronic COC (NOAEC or NOAEL) for any ke y aquatic receptor group is exceeded for 20 days or more based on results from the high-end scenario, then potential chronic risks for such receptor groups
are indicated.Page 97 of 103 

### APPENDIX E: ECOLOGICAL EXPOSURE MODELING METHODOLOGY

Methodology for Estimating Water Column Exposure to Aquatic Organisms
from Release of ATMD from Recirculating Cooling Towers

The General Population and Ecological Expos ure from Industrial Releases module of EFAST (Exposure and Fate Assessment Screening T ool) was used to estimate potential risks from exposure of aquatic organisms to ATMD downstream of recirculating coo ling towers. Key input parameters required to run th is module of E-FAST include:

 Environmental release of ATMD to surface water (kg/site/day);

 Concentrations of concern (COC ) for aquatic organisms (ug/L);

 Standard Industrial Classification (SIC) code (s) selected to represent recirculating cooling tower facilities;

 Wastewater treatment rem oval of ATMD (percent);

 Annual number of days of release to surface water (days per year); and

 Selection of high-end or average case scenario.

A discussion of the basis of high-end and av erage case scenario results is included at the end of this Appendix. The approach used to esti mate aquatic exposures to ATMD from release
of blowdown water from recircul ating cooling towers can be de scribed in four steps:

 Step 1: Estimate environmental release to surface water from r ecirculating cooling tower blowdown water from recircul ating cooling tower blowdown water (kg/site/day);

 Step 2: Determine percent removal during wastewater treatment;

 Step 3: Derive concentrations of conc ern (COC) for aquatic organisms from LC 50 and NOAEC values; and

 Step 4: Estimate aquatic exposures from releases of recirculating cooling tower blowdown water to surface water using th e general population exposures from industrial releases module of E-FAST.

STEP 1: Estimate Environmental Release to Surface Water from Recirculating Cooling Tower
Blowdown Water (B) in kilograms per site per day

A generic scenario developed by OPPT/C EB (Office of Pollution Prevention and Toxics/Chemical Engineering Branch) for recirc ulating cooling towers (USEPA, undated) was used to estimate daily releases to surface wate r of ATMD in blowdown water in kilograms per site per day.Page 98 of 103 The following equation is used to estimate rel eases of antimicrobial pesticide to surface
water from blowdown:

B = (0.6%) (X R ) (R) (5760 x 10 -06 min-kg/day-gal)

where:

B = release of antimicrobial pesticide via bl owdown water to surface water (kg/site/day);

X R = concentration of antimic robial pesticide in recirc ulating water (ppm); and

R = recirculation rate of coo ling water (gallons per minute).

The conversion factor, 5760 x 10 -06 min-kg/day-gal is derived from:

(1440 min/day) (4 kg/gal) (10 -06 ppm) in which the blowdown water is assumed to have a specific gravity of 1.0, thus 1 liter weighs 1 kilogram, and the conversion of 3.78 liters per gallon is expressed in kilograms per gallon and rounded up to the nearest significan t figure. The value, 0.6% is the percentage of cooling tower water that is assumed to be released to surface water via
blowdown.

The following input values were used in this calculation:

 X R : concentration of ATMD in recirculat ing cooling tower water – 0.5 to 40 ppm ATMD acid equivalents (derived from info rmation on the label for “Antimicrobial ATMD 15%” (EPA Reg. No. 464-619) based on the range of product application rates (0.5 to 41 fluid ounces per 1000 gallons of water) adjusted for product density (8.5 pounds per gallon) and expressed as ATMD acid equivalents (12.8%)

 R:recirculation rate of co oling water– 2000 gallons per minute for a moderate-size cooling tower (default value based on st andard scenario de veloped by OPPT/CEB)) and 100,000 gallons per minute for a large-si ze cooling tower (default value based on standard scenario developed by OPPT/CEB).

The table that follows presents values of environmental releases of ATMD modeled for large-size and moderate-size cooling towers ac cording to product application rate, product density, and ATMD concentra tion in acid equivalents.

STEP 2: Determine Percent Removal During Wastewater Treatment

Data from an activated sludge sorption is otherm test (OCSPP Guideline 835.1110) that were submitted to the Agency for review indicate that based on 4 to 6 hours of treatment in an activated sludge basin from 71-92 percent of AT MD is removed via its sorption to activated sludge (Schaefer, E and A Ponizovsky. 2012 (M RID 490402051); see references in Appendix A for full citation). For the purpose of this exposur e and risk assessment, estimates were provided
based on 4 hours of treatment w ith 71 percent removal via sorpti on to activated sludge and based on 6 hours of treatment with 92 percent re moval via sorption to activated sludge.Page 99 of 103 There is no information on the product labe l to indicate that bl owdown water must be treated prior to discharge to surface water. Consequently, exposures and risks to aquatic organisms were also estimated assuming that bl owdown water could be di scharged directly to surface water without treatment. In this case, it was assumed that there would be no removal of ATMD from blowdown water prior to its discharge to surface water.

STEP 3: Estimate Concentrations of Concern (COC) for Aquatic Organisms

The results of the DtD module are expressed as number of days of exceedance of COCs for aquatic organisms. The Agency uses the most sensitive ecotoxicology endpoints for surrogate species to assess risk to each aqua tic receptor group, such as freshwater fish, freshwater invertebrate, sediment-dwelling invert ebrate, and aquatic plants. COCs for acute effects were determined by dividing LC 50 values from acute toxicity tests on aquatic vertebrates and invertebrates by 2. COCs for chronic eff ects for non-listed species were based on No Observed Adverse Effects Concentration (NOAEC) values from tests on aquatic vertebrates and invertebrates. COCs for listed endangered and threatened aquatic organisms were determined by dividing LC 50 values from acute toxic ity tests on aquatic vertebra tes and invertebrates by 20. Acute COCs for aquatic vascular plants and algae are based on EC 50 values. COCs for endangered algae and aquatic vascular plants are based on NOAEC values.

STEP 4: Estimate General Population and Ecological Exposure from Industrial Releases

E-FAST, version 2.0, was used to determine the magnitude and fre quency of exposure of aquatic organisms from releas es of ATMD via blowdown wate r from recirculating cooling
towers. For detailed information on the featur es, data, and methods on which the models in EFAST, version 2.0, are based, refer to the latest version of the Docume ntation Manual for EFAST, version 2.0 (USEPA 2007). This discussion is limited to summarizing the steps required to estimate exposure of aquatic organisms to blowdown water from indus trial use of ATMD in recirculating cooling towers using the Gene ral Population and Ecological Exposure from
Industrial Releases module of E-FAST with th e PDM (probabilistic dilu tion model) option. The user is guided through a series of menus or page s that provide prompts indicating where the user should input data. Key input parameters need ed to run this module and option include:

 Environmental release to surface water in kg/site/day (estimated from Step 1);

 Percent removal of ATMD during wastew ater treatment ( from Step 2); and

 Concentrations of Concern (COC) for aqua tic organisms (estimated from Step 3).

One of the first screens that appears when running the General Population and Ecological Exposure from Industrial Releases module of E-FA ST is the physical/chemical and fate inputs screen; Upon accessing this screen, the user must enter the following information:

 Chemical identificati on (e.g., CAS number);Page 100 of 103  Chemical name or abbreviation;

 Bioconcentration factor (measured or estima ted) (used to estimate human exposure from ingestion of fish);

 Percent wastewater treatment re moval (measured or estimated);

 Percent adsorption to wastew ater treatment sludge (measured or estimated); and

 Percent drinking water treatment removal (in the absence of data, assume no removal).

The user must also select the appropriat e models for estimating exposure to aquatic organisms. (In this instance, the appropria te model to use is th e general population and ecological exposure from industrial releases to surface water model with the option to also run the probabilistic dilution model.) Next, the user accesses the “Release Information Page”. This page consists of thr ee sub-pages including:

 general release information;

 select a facility; and

 select an SIC code.

The “select a facility” subpage, which accesses a database of site-specific information for manufacturing facilities, is not applicable for estimating exposures from processing and industrial use. To estimate exposures to aqua tic organisms from surface water releases from processing or industrial use, th e user must provide input valu es for the “general release information” subpage and the “select an SI C code” subpage. On the general releases information subpage, the user must input the following:

 type (media) of release (i.e., surface water, landfill, and/or ambient air); in this case, the user would select “surface water”.

 amount of release in kg/site /day, based on the results from CEB’s generic scenario (from Step 1 of this appendix) ;

 days per year of release, based on results from CEB’s generic scenario; the default value for the recirculating coo ling towers scenario is 360.

 Upon being present with a choice of selec ting “SIC code anal ysis” or “facility analysis”, select SIC code analysis. A me nu of SIC code descrip tions will appear on the screen and the user will be prompted to select one; in this instance, the appropriate SIC code description would be “Steam Electric Power Plants”.

 Input the number of cooling tower site s; since there is no production volume information available for ATMD used in reci rculating cooling towers that can be used to derive this input, no value is entered.

 In the box, “enter release activity ”, the user has the option to enter a description of the release; in this case, an apt description might be “indirect rele ase of cooling tower blowdown”.

 Place a check in the box, “include PDM run”.

 Enter three values for concentrations of concern.Page 101 of 103  Select results for high en d or average exposure.

 Finally, check the box, “Release activities co mpleted? Continue to Exposure Factors page.” Upon checking this box, the Exposure Factors page will appear.

The information in the exposure factors page is not used to estimate exposures to aquatic organisms, but is used to quantify human exposur es from ingestion of drinking water and fish. This page includes default values for body wei ght, exposure duration, averaging time, and acute and chronic drinking water and fi sh ingestion rates. These valu es are automatically selected unless the user changes them.



### Methodology for Estimating Exposure to Aquatic Organisms from Release of

ATMD from Once

­ through cooling systems

With the exception of Step 1 described in the approach used to estimate environmental releases of active ingredient to surface water from recirculating cooling tower s, the methodology used for estimating exposure to aquatic organi sms from release of ATMD from once-through cooling systems is the same as that used for estimating exposure to aquatic organisms from recirculating cooling towers. Whereas the release of active ingredient to surface water from recirculating cooling towers is limited to cooling tower blowdown water, the release of active ingredient to surface water from once-through coo ling systems is based on the intake flow. Consequently, Step 1 of the approach for estimating environmental releases to surface water from recirculating cooling tower blowdown water (B) in kilograms per site per day would be
modified as follows:

Convert once-through cooling tower throughput in million gallons per day (MGD) to liters per day

Convert maintenance concentr ation of ai in ppm to ug/L

Use throughput in liters per da y and concentration of ai in ug/ L to derive kilograms of ai per site per day

For example, to convert 2 MGD of throughput w ith 2.5 ppm of product at 1.7% active ingredient to kilograms per site per day of active ingredient released to surface water:

Convert 2 MGD to liters per day.

2,000,000 gal/day x 3.785 liters/gallon = 7,570,000 liters/day

Convert ppm ai to ug/L.

2.5 mg/L product x 0.017 active ingredie nt/product x 1000 ug/mg = 42.5 ug/literPage 102 of 103 Use liters of throughput per day and concen tration of ai in ug/liter to determine kg/site/day

42.5 ug/L x 7,570,000 liters/day x 1 kg / 10 9 ug = 0.3217 kg/site/day



### Description of High

­ End Versus Average Case Scenario

The General Population and Ecological Expos ure from Industrial Releases module of EFAST uses environmental releases estimated in Step 1 of this Appendix, stream dilution factors (i.e., the ratio of stream flow to industrial wastewater treatmen t plant flows), and wastewater treatment removal efficiency to provide both hi gh-end and median time-averaged surface water
concentrations of a chemical substance immediat ely downstream of a discharge point. Stream flows are not single point estimates since streams have a highly variable seasonal flow pattern. PDM uses probability distributions as inputs and calculates the resulting probability distribution
of the stream concentration.

To determine stream dilution factors for indus trial uses of chemical substances such as ATMD used in recirculating cooling towers, a re presentative SIC code mu st be selected. The model will develop a distribution of stream diluti on factors based on the ratio of stream flows to plant flows for facilities that belong to a specifi ed SIC code. The distribution of stream flow
values used is those immediatel y downstream of the facilities that belong to a specified SIC
code. For this risk assessment , stream dilution factors (SDFs) for recirculating and once-through cooling systems were based on the ratio of receiving stream flows to facility effluent flows for those facilities included in the steam electric pow er plants SIC code (S IC 4911). For the highend scenario, results of the number of days per year that COCs are exceeded are based on the upper 10 th percentile of SDFs. For the average case scenario, results of th e number of days per year that COCs are exceeded are based on the 50 th percentile of SDFs. For the upper 10 th percentile SDFs, or high-end scenari o, the stream flow to plant flow ratio is relatively low since plant flows can contribute considerable volume to the flow of the stre am and resulting surface water concentrations can be relatively high. For the 50 th %ile SDF, the stream flow to plant flow ratio is more typical.



### Methodology for Estimating Sediment Exposure to Benthic Aquatic Organisms
from Release of ATMD from Once

­ Through and Recirculating Cooling Towers

Two approaches were used to estimate sedime nt concentrations to which benthic aquatic organisms would be exposed. Inputs used to es timate freshwater sediment concentrations
included:Page 103 of 103  Estimated surface water concentrations based on results from the Industrial Releases module of E-FAST;

 Average .K f value from a study on sorption of formulated Duomeen C to five soils (Schaefer, EC. and AA Ponizovsky. 2012b. MRID 490040206; (See reference cited in Appendix A for co mplete citation))

Inputs used to estimate estuarine/marine sediment concentrations included:

Effluent concentration of ATMD at the end-of-pipe (42.5 ug/L)

Average K f value from MRID 490040206 as referenced above.

The following equation is used to estimate sediment concentrations:

C s = K f x C w x 1 mg/1000 ug

Where

C s is the concentration of ATMD in the sediment (mg/kg sediment),

K f is the average leaching adsorption/des orption value (L/kg) (See Table 21), and

C w is the concentration is surf ace water or end-of-pipe concentr ation of ATMD (i.e., 42.5 ug/L).



### APPENDIX E

– REFERENCES

Ackerman, D, F Ghillebaert, and MW Glass. 2013. Duomeen C Water Concentration Modeling for Cooling Water Towers and Once-Through In dustrial Cooling Water Systems. MRID
49040220.