### ~~~~

# ia~

# ~ \

# ~~**!** UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C. 20460

## ~**~ ~~~** 

MEMORANDUM

SUBJECT :

T O:

FROM:

THRU:

Exec ut ive s u mmary September 7, 2 0 1 1 OFFICE OF CHEMICAL SAFETY

AND POLLUTION PREVENTION

Amines, C lO

- 1 6 alkyldimethy l, N-oxides

. Product Chemistry,

Environmental Fate, and Ec ol ogical Effects Scoping Document for Registration Review.

PC Code: 000439 DP Barcode: 392 7 00

Decision No

. : 452862 Registration No. : See Table 1

Petition No(s).: NA Regulatory Action : Ecological

Environmental Scopin g Document

for Registration Review
Risk Assessment Type : Single Case No. : 5003

chemical

TXRNo

. :NA CAS No

. : 70592

- 80

- 2

MRlD Nos. : See Table 2 and Pg

. no

. 5 40 CFR: None

Seiichi Murasaki, Chemical R e v iew Manager Regulatory Management Br an ch II

Antimicrobials Division (75 1 OP)

Srinivas Gowda, Microbiolo g is t 

## S 

## -0\**~** 

## " \C0l

## ~~ Risk Assessment and Scienc e Support Branch (RASSB)

Antimicrobials Division (75 1 OP)

Nader Elkassabany, Branch C hief

# ~~ . Siroos Mostaghimi, Peer**Re iewer** **~ ~**  Risk Assessment and Scienc e Support Branch (RAS'SBf

Antimicrobials Division (75 1 OP)

ADAO is an end use product registered for r es i dential use as an antibacterial dish

de t ergent. All product chemistry data requirement s have been satisfied for ADAO. Agency's in-house database does not have any acc e ptable environmental fate and

transport data on ADAO which are required to con d uct an environmental fate assessment

for residential antibacterial dishwashing detergents that may potentially pass through

waste wa t er treatment plants (WWTPs) and may b e discharged into terrestrial and aquatic

environments. ADAO is on the 2007 Organization for Economic Co

- operation and Developme n t (OECD) list of high production volume chemicals (The 2007 OECD List of

Page 1 of 1 6Page 2 of 16

High Production Volume Chemicals, Series on Testing and Assessment, Number 112, 23

October 2009 ) and is among those chemicals for which a Screening Information Data Set (SIDS) has been performed. An examination of the chemical structure and a review of information in the SIDS Initial Assessment Report for Amine Oxides (S IDS Initial Assessment Report for SIAM 22, Paris, France, 18

- 21 April 2006) indicates that a high percentage of amine oxides are removed by conventional sewage treatment systems. According to the SIDS Initial Assessment Report, ―Removal of amine oxides in biological wastewater treatment has been studied in laboratory simulation studies (>99.8% removal, OECD 303A study) as well as through monitoring activities in different geographies; the main removal mechanism can be attributed to mineralization

and an av erage removal number of 98% can be assumed as applicable for secondary activated sludge treatment.‖ The Environmental Fate and Pathways section of the SIDS dossier on this particular class of amine oxides (CAS No. 70592

- 80

- 2) summarizes monitoring studies and biodegradation studies that appe ar to substantiate this claim.

To be able to give merit to this claim, the Agency would need to review and evaluate the primary references cited in this SIDS dossier. Without reviewing and evaluating these primary ref erences and reaching the same conclusions as those presented in the SIDS Initial Assessment Report, f or this assessment the Agency anticipates needing fate data such as hydrolysis and photodegradation in water, modified activated sludge respiration inhibit ion, activated sludge sorption isotherm; ready biodegradability, porous pot test, or simulation tests to assess the biodegradability of chemicals discharged

in wastewater , or simulation test

– aerobic sewage treatment: A

. Activated Sludge Units.

ADAO is p ractically non

- toxic to mammals on an acute oral basis; and moderately toxic

to freshwater fish and invertebrate. For the ecological risk assessment, including an endangered species assessment for all uses, t he Agency anticipates needing the acute

avian or al toxicity data and algal toxicity data.

Introduction

Amines, C 10 - 16 - alkyldimethyl, N

- oxides also chemically known as A lkyl (C 10

- 16 )

d imethyl a mine o xide s (ADAO)

, are non

- ionic

, dipolar surfactants which are generally used in detergents at low levels in conjunction with other surfactants. A DAO are effective in the presence of greasy soil and are commercially sold as 26

- 31% aqueous

solution s

.

Nonionic surfactants do not ionize in aqueous solution, because their hydrophilic group is of a nondissociable type, such as alcohol, phenol, ether, ester, or amide. The dimethyl(C 10 - C16 - alkyl)amine N

- oxides (ADAO) are produced as a mixture comprised of

di methyldecylamine (CDAO, C 10 ), dimethylundecylamine (UDAO, C 11 ), dimethyldodecylamine (DDAO, C 12 ) , dimethyltridecylamine (TDAO, C 13 ), dimethyltetradecylamine (MDAO, C 14 ), dimethylpentadecylamine (PDAO, C 15 ), and dimethyhexadecylamine (HDAO, C 16 ) N

- oxides. Mixtures of (C 12 - C 16 ) ADAO are referred to

as coco

— dimethylamine oxide, which is a clear corrosive liquid that is soluble in water and polar solvents. It decomposes before boiling at atmospheric pressure. The amine oxides are dipolar surfactants which can undergo several types of reactions associated with the amine oxide moiety.Page 3 of 16 ADAO was initially registered as a pesticide in the United States in 1999 for use

as an antibacterial dish detergent. C urrently there is only one end

- use product registered

for res idential use as an antibacterial dish detergent listed in Table 1

. The product is not for use in dishwasher. It is intended for handwashing of dishes, dishware, cutlery, utensils, and cutting boards, and for general dishwashing use to kill 99.9% of bacteria

such as Salmonella choleraesuis, Escherichia coli, Staphylococcus aureus, E. coli 0157, and Listeria monocytogenes on dishware (dishes/utensils)

. To kill bacteria on dishes the product is to be applied manually as a concentrate directly o nto dishes, spread over the surface and allowed to stand 5 minutes before rinsing. A Reregistration Eligibility Decision (RED) has not been issued by EPA for Amines , C 10

- 16 - alkyldimethyl, N

- oxide s
, because the initial registration date was after the Novemb er 1984

, the mandated cutoff for initiation of the RED process.

Table 1. Registere d Product of ADAO

Registration # Registration Name Company Name Formulation Type % of A ctive

Ingredient

3573

- 62 Cleaning Magic II Proctor & Gamble Ready to use

solutio n 5 .2

EPA Reg. No. 3573

- 62 Cleaning Magic II Active Ingredient: Alkyl (C 10

- 16 ) dimethyl amine oxide

.. 5.2%

For residential use only. Contains no phosphate.

Not for use in dishwasher. For general dishwashing, use as any dishwashing detergent.

Concentrated Dishwashing Detergent and Antibacterial Treatment.

Antibacterial action.

Kills 99.9% of bacteria on dishes such as Salmonella choleraesuis, Escherichia coli, Staphylococcus aureus, E. coli 0157, and Listeria monocytogenes

. Makes dishes/dishware/plastic dis hware/plastic cutting boards/cutlery/utensils 99.9%

bacteria free. Kills 99.9% bacteria on dishes/dishware/plastic dishware/plastic cutting boards/cutlery/utensils that could contaminate clean dishes.
Kills 99.9% of common household bacteria, bacteria asso ciated with food preparation

and common kitchen bacteria. Helps fight bacteria on dishes/dishware/plastic dishware/plastic cutting boards/cutlery/utensils. Help reduce the risk of cross

- contamination from treated surfaces in kitchen. May help prevent the t ransfer of bacteria from dishes to other kitchen surfaces.Page 4 of 16 The Agency has conducted a review of the available product chemistry, environmental fate, and ecotoxicity data for ADAO

. The findings are summarized below.

A. Product Chemistry Summary ( Technical 32 % aqueous s olution of ADAO)

Common Name: Amine oxide , C 10 - 16 - alkyldimethyl ; Amine oxide (C 10 - C 16 )Alkyldimethylamine oxide

Chemical Name s : Amines, C 10 - 16 - alkyldimethyl, N

- oxide

A lkyl (C 10

- 16 ) d imethyl a mine o xide (ADAO)

A lkyl d imethyl a mine o xide (ADAO)

IUPAC Name: N, N

- dimethyltridecan

- 1

- amine oxide

Trade and Other Names: AO

- 1280

- LN (32% aqueous solution)

OPP Chemical Code: 000439 CAS Registry Number: 70592

- 80

- 2

Case: 50 03 Chemical Family: Sur factant

Molecular Formula: C 15 H 33 NO ; C 10

- 16 H 21

- 33 N(CH 3 ) 2 O Molecular weight: 2 35.7 [g/mol] (mean mixture value)

Molecular Structure:

Color: Light yellow

Physical State: Liquid

Odor: Weedy odor

Stability: Stable up to 100 ° F; other than excessive heat which

leads to color degradation, no other conditions affect stability.

Oxidation/Reduction: Low capacity to act as an oxidizing agent. No reducing capacity. The solution will cause rusting of

non

- stainless ferrous metals.Page 5 of 16 Flammability

- Flash Point: Over 300 ° F

Explodability: Amine ox ide solution does not contain any explosive ingredient or fractional group therefore guid e line is no t applicable.

Storage Stability: Stable up to 100 ° F; other than excessive heat which leads to color degradation, no other conditions

affect stabil ity.

Miscibility: Amine ox ide solution is not an emuls ifiable liquid bearing directions for dilution with petroleum

solvents , and therefore guideline is not applicable.

Corrosion Characteristics: No corrosive characteristics other than rusting non

stainless ferrous metals.

Dielectric breakdown voltage: 

### Not applicable

.

pH: 7.2

UV/Visible absorption: Not provided.

Viscosity: 30

- 50 cps at 25 ° C

.

Melting point: Not applicable

.

Boiling Point: 100 ° C at 1 atm

.

Density: 1.0 at 25 ° C Specific Gravity: 1.0 at 25 ° C

Dissociation Constant: Not applicable . Has no measurable dissociation

constant.

Log K o/w : 5.3 (estimated)

.

Solubility: Completely soluble in water at 70 ° F

.

Vapor Pressure: 17.5 mm Hg at 68 ° F

.

Enf orcement Analytical

Method: Titration

.

All product chemistry data requirements have been satisfied for the active ingredient ADAO (MRID s 444349

- 01, 444349

- 02, 444349

- 03, & 444347

- 04 )

.Page 6 of 16

B. Environmental Fate Summary

The following f

ive non

- guideline environmental fate stud ies were submitted by

the P roctor & G amble Company

. These studies were reviewed by the Agency and found

insufficient

/rejected because they were very old and /or not conducted according to the

current EPA guidelines.

1. A Biodegradability Study of Dodecyl Dimethyl Amine Oxide (DDAO) (MRID 44434914)

. 2. Isolation, Identification and Quantitation of the Semi

- continuous Activated Sludge Metabolite(s) of Dodecyldimethylamine Oxide (DDAO) (MRID 44434915)

. 3. Biodegradation Study of E

- 5139.01 Continuous Activated Sludge Simulation Test (MRID 44475205)

. 4. Fate of (carbon 14)

- Dimethyldodecylamine Oxide (DDAO) During Activated Sludge Treatment (CAS Test) (MRID 44475206).

5. Hydrolysis of TSIN GTS02902 as a Function of pH (MRID 46008802).

No risk assessment was performed for ADAO at the time of the registration . The Agency has not received any acceptable guideline environmental fate studies on ADAO, which are required to conduct an environmental fate assessment for residential

antibacterial dishwashing detergents (including ADAO) that may potentially pass through waste water treatment plants (WWTPs) and may be discharged into terrestrial and aquatic

environments. ADAO is on the 2007 Organization for Economic Co

- operation and Development (OEC D) list of high production volume chemicals (The 2007 OECD List of High Production Volume Chemicals, Series on Testing and Assessment, Number 112, 23 October 2009) and is among those chemicals for which a Screening Information Data Set (SIDS) has been perf

ormed. An examination of the chemical structure and a review of information in the SIDS Initial Assessment Report for Amine Oxides (SIDS Initial Assessment Rep ort for SIAM 22, Paris, France, 18

- 21 April 2006) indicates that a high percentage of amine oxid es are removed by conventional sewage treatment systems. According to the SIDS Initial Assessment Report, ―Removal of amine oxides in biological wastewater treatment has been studied in laboratory simulation studies (>99.8% removal, OECD 303A study) as we ll as through monitoring activities in different geographies; the main removal mechanism can be attributed to mineralization and an average removal number of 98% can be assumed as applicable for secondary activated sludge treatment.‖ The Environmental Fat e and Pathways section of the SIDS dossier on this particular class of amine oxides (CAS No. 70592

- 80

- 2) summarizes monitoring studies and biodegradation studies that appe ar to substantiate this claim.

To be able to give merit to this claim, the Agency would need to review and evaluate the primary references cited in this SIDS dossier. Without reviewing and evaluating these primary references and reaching the same conclusions as those presented in the SIDS Initial Assessment Report, f or this environment al fate assessment the Agency anticipates needing those data outlined on page 10 of this document

.Page 7 of 16 Water Quality

ADAO is not identified as a cause of impairment for any water bodies listed as impaired under section 303(d) of the Clean Water Act, based on information provided at the Agency‘s National Pesticides Cause of Impairment of Waters website (searched April 7, 2011) 1 . In addition, no Total Maximum Daily Loads (TMDL) have been developed for ADAO, based on information provided at the Agency‘s Natio nal Pesticide TMDL web site (searched April 7, 2011) 2 . More information on impaired water bodies and

TMDLs can be found at http://www.epa.gov/owow/tmdl/ . The Agency invites submission of water quality data for this pesticide. To the extent possible, data should conform to the quality standards in Appendix A of the OPP Standard Operating Procedure: Inclusion of Impaired Water Body and Other Water Quality Data in OPP’s Registration Review Risk Assessment and Mana gement Process (see: http://www.epa.gov/oppfead1/cb/ppdc/2006/november06/session1

- sop.pdf ), in order to ensure they can be used quantitatively or qualitatively in pesticid e risk assessments.

C. Ecological Effects Summary

No ecological risk assessment was performed for ADAO at the time of the registration. Available e cotoxicity guideline studies and the r esults are summarized in

Table 2 . The Agency's conclusions for the terrestrial and aquatic effects studies are as

follows.

a. Toxicity to Terrestrial Animals

Birds , Acute and Subacute

No a vian acute oral toxicity data have been submitted. For the ecological risk assessment, including an endangered species assessment for all uses,

t he Agency anticipates needing the a vian acute oral toxicity data outlined

on page 8 of this document

.

Toxicity to Mammals

Acute toxicity data for ADAO show practically non

- toxicity for oral dose (oral LD 50 = 4800 mg/kg).

There is currently no 2

- generation rat repro duction study but in the human health scoping document it has been identified as a data gap.

b . Toxicity to Aquatic Animals

1

. http://iaspub.epa.gov/tmdl_waters10/attains_nation_cy.cause_detail_303d?p_cause_group_id=885

2
http://iaspub.e pa.gov/tmdl_waters10/attains_nation.tmdl_pollutant_detail?p_pollutant_group_id=885&p_p ollutant_group_name=PESTICIDESPage 8 of 16 Freshwater Fish and Invertebrates

A DAO is moderately toxic to freshwater fish and aquatic inve rtebrates

.

The submitted ecological effects studies were reviewed as supplemental and adequate for purposes of labeling: thus these studies do not need to be repeated. The data showed that ADAO is moderately toxic to bluegill sunfish, freshwater fish, with the LC 50 values ranging from 3.1

- 6 4 ppm and to Daphnia magna, a freshwater aquatic invertebrate with LC 50 value as 1.01 ppm.

d. Toxicity to Aquatic Plants

Freshwater Algae

No algal toxic ity data have been submitted. For the ecological risk assessment, including an endangered species assessment for all uses, t he Agency anticipates needing the algal toxicity data outlined on page 10 of

this document

.

Table 2. Ecotoxicity Data Summary for A DAO

MRID GUIDE

LINE COMMON

NAME TAXONOMIC

NAME TEST

TYPE AI STUDY

TIME DOSE

TYPE TOXI

CITY TOX

LEVEL NOEL STUDY

STATUS TOX

CATEGORY

Freshwater Fish Acute Toxicity

44434911 850.1075

(72

- 1) Bluegill

sunfish Lepomis

macrochirus S N.R. 96 hr LC 50 6.4 PPM N.R. Supple

mental Moderately

toxic

44434912 850.1075

(72

- 1a) Bluegill

sunfish Lepomis

macrochirus S N.R. 96 hr LC 50 3.13 PPM 1.20 Supple

mental Moderately

toxic

Freshwater Invertebrate Acute Toxicity

44434913 850.1010

(72

- 2) Water

flea Daphnia

magna F N.R. 96 hr E C 50 1.01 PPM 0.70 Supple

mental Moderately

toxic

Terrestrial Mammalian Acute Oral Toxicity

44475201 870.1100

81

- 1 Rat

----- ----- 27.72

----- LD 50

LD 50 (Combined) 5400(M)

3900(F)

4800 mg/kg /bw

----- Acceptable Practically

non

- toxic (III)

Test Type

— F : flow

- through ; S: static.

Tox Level

— mg /kg/bw : milligrams per kilogram

- body weight; ppm : parts per million (equivalent to milligrams per liter (mg/L) for aquatic exposures) Categories of acute toxicity for aquatic organisms (U.S. EPA, 2004) based on EC 50 /LC 50 (mg/L): < 0. 1 very highly toxic; 0.1

- 1 highly toxic; >1

- 10 moderately toxic; >10

- 100 slightly toxic; >100 practically nontoxic. Categories of acute toxicity to terrestrial animals, avian and mammalian (U.S. EPA, 2004). LD50 (mg/kg bw): < 10 very highly toxic; 10

- 50 highly toxic; 51

- 500 moderately toxic; 501

- 2000 slightly toxic; >2000 practically non

- toxic.

Adverse Ecological Incidents

There are no reported incidents in the Agency's Ecological Incident I nfo rm ation System (EII S) regarding A DAO

. The absence of documented incidents does not necessarily mean that such incidents did not occur.Page 9 of 16 Ecological Effects Risk Assessment

An ecological risk assessment was not conducted on the A DAO  ̳s anti bacterial dishwashing detergent use pattern described in this document. A DAO‘s uses that have potential for environmental exposure are down the drain antibacterial dishwas h ing detergent discharges. The Agency needs to conduct environmental fate an d ecological

risk assessments for antibacterial dishwas h ing detergents that potentially pass through waste water treatment plants (WWTPs) and may be discharged into terrestrial and aquatic

environments. For this ecological risk assessment, including an en dangered species assessment for all uses, t he Agency anticipates needing the avian acute oral and algal toxicity data outlined on page 1 0 of this document

.

The Agency has not conducted a risk assessment for ADAO that supports a complete endangered species effects determination. The ecological risk assessment planned during registration review will allow the Agency to determine whether A DAO ‘s

use has ―no effect ‖ or ―may affect‖ federally listed threatened or endan gered species (listed species) or their design at ed critical habitats. When an assessment concludes that a pesticide‘s use ―may affect‖ a listed species or its designated critical habitat, the Agency

will consult with the U.S. Fish and Wildlife Service and /or National Marine Fisheries Services (the Services), as appropriate.

Environmental Fate and Ecotoxicity Data Gaps and Anticipated Work

Environmental fate and ecological risk assessments have not been conducted for

A DAO . The Agency needs to conduct environmental fate and ecological risk

assessments for residential antibacterial dishwashing detergents that potentially pass through waste water treatment plants (WWTPs) and may be discharged into terrestrial and aquatic env ironments. ADAO is on the 2007 Organization for Economic Co

operation and Development (OECD) list of high production volume chemicals (The 2007 OECD List of High Production Volume Chemicals, Series on Testing and Assessment, Number 112, 23 October 2009) a nd is among those chemicals for which a Screening Information Data Set (SIDS) has been performed. An examination of the chemical structure and a review of information in the SIDS Initial Assessment Report for Amine Oxides (SIDS Initial Assessment Report f or SIAM 22, Paris, France, 18

- 21 April 2006) indicates that a high percentage of amine oxides are removed by conventional sewage treatment systems. According to the SIDS Initial Assessment Report, ―Removal of amine oxides in biological wastewater treatmen t has been studied in laboratory simulation studies (>99.8% removal, OECD 303A study) as well as through monitoring activities in different geographies; the main removal mechanism can be attributed to mineralization and an average removal number of 98% can be assumed as applicable for secondary activated sludge treatment.‖ The Environmental Fate and Pathways section of the SIDS dossier on this particular class of amine oxides (CAS No. 70592

- 80

- 2) summarizes monitoring studies and biodegradation studies tha t appe ar to substantiate this claim.

To be able to give merit to this claim, the Agency would need to review and evaluate the primary references cited in this SIDS dossier. Without reviewing andPage 10 of 16

evaluating these primary references and reaching the same c onclusions as those presented in the SIDS Initial Assessment Report, the Agency anticipates needing the proposed

environmental fate and ecotoxicity data for A DAO and/or any of its major degradation products that are of potential concern for all registered uses of A DAO . The following

environmental fate and ecotoxicity data are needed to conduct an environmental fate and ecological risk assessment:

The Agency anticipates needing the following data to conduct a complete

environmental fate assessment for resi dential antibacterial dishwashing detergent use:

o (GLN 835.2120) Hydrolysis;

o (GLN 835.2240) Photodegradation in water;

o (GLN 850.6800) Modified Activated Sludge Respiration Inhibition ;

o (GLN 835.1110) Activat ed Sludge Sorption Isotherm;

o (GLN 835.3110) Ready biodegradability, (GLN 835.3220) Porous Pot Test, or (GLN 835.3280) Simulation Tests to Assess the Biodegradability of Chemicals Discharged to Wastewater , or (GLN 835.3240) Simulation

Test

– Aerobic Sewage Treatment: A. Activated Sludge Units 3

.

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

o (GLN 850. 2100 ) Acute avian oral t oxicity; and

o (GLN 850.5400) A lgal toxicity (Tier II) using freshwat er green alga, Selenastrum capricornutum.

3 The results of the Activated Sludge Respiration Inhibition Test (ASRI) determine which of these biodegradation tests are required. If the ASRI test EC 50 is less than or equal to 20 mg/L, then either the Biodegradation in Activated Sludge Study or the Por ous Pot Test is required. If the ASRI test EC 50 is greater than 20 mg/L, then the applicant must choose either: (i) Ready Biodegradability or (ii) Biodegradation in Activated Sludge or the Porous Pot Test. If the antimicrobial passes the ready biodegrada bility study, then no further testing is required. If, however, the antimicrobial fails the ready biodegradability study, then the Biodegradation in Activated Sludge or the Porous Pot study is required.Page 11 of 16



### Appendix A. Environmental Fate Guideline Study Justifications

Guideline Number: 835.2120 Study Title: Hydrolysis
Practical Utility of the Data 1) What is the value of the study? Data characterizing the rate of hydrolytic degradation of ADAO and/or the formation and decline of degradates is important in determining the persistence and concentrations of ADAO and potential degradates over time in various aquatic environments. For ou tdoor uses, ADAO can reach surface water through direct contact or discharge to WWTPs. ADAO may also reach surface water or groundwater through run

- off or leaching processes. The Agency will evaluate the potential risks of concern.

2) How would the data be used? The data would establish the significance of chemical hydrolysis as a route for degradation and identify, if possible, the hydrolytic transformation products formed that may adversely affect non

- target organisms and may contaminate water and food source of aquatic organisms. The data would also help establish the hydrolytic half

- life of ADAO and possibly degradates, and assist in developing a degradation pathway.

3) How could the data affect the risk assessment? The results of hydrolysis data would indica te if ADAO is persistent or if it degrades into other products that may adversely affect nontarget organisms and may contaminate their food and water and possibly soil.

4) What is triggering the need for this data? Hydrolysis data is needed to conduct the fate assessment to support antibacterial dishwashing detergent

uses for ADAO

.

Guideline Number: 835.2240 Study Title: Photodegradation in water
Practical Utility of the Data 1) What is the value of the study? Biocides introduced into aqueous systems in the environment can undergo photolytic transformation by sunlight. Results from the photolysis study will indicate the stability and persistence of ADAO and potential degradates in an aquatic environment when ex posed to sunlight. The Agency will evaluate the potential risks of concern.

2) How would the data be used? The data would establish the significance of chemical photolysis as a route for degradation and identify, if possible, the photolytic degradation products formed that may adversely affect non

- target organisms and may contaminate water and food source of aq uatic organisms. The data would also help establish the photolytic half

- life of ADAO and possibly degradates, and assist in developing a degradation pathway.

3) How could the data affect the risk assessment? The results of photolysis data would indicate if ADAO is persistent or if it degrades into degradation products that may adversely affect nontarget organisms and may contaminate their food. The results of the photolysis data would expand the understanding of the results of the hydrolysis data since environmental aquatic conditions usually involve exposure to sunlight.

4) What is triggering the need for this data? Aqueous photodegradation data is needed to conduct the fate assessment to support antibacteri al dishwashing detergent uses for ADAO

.Page 12 of 16

Guideline Number: 835.1110 Study Title: Activated Sludge Sorption Isotherm
Rationale for Requiring the Data Data from this study are needed to determine the sorption potential of activated sludge for the removal of specific chemical compounds in biological wastewater treatment plants (WWTPs). If the chemical is not sorbed or biodegraded, then it would pass through a biological treatment system unaffected, potentially contaminating surface and drinking waters where it may then have the potential to adversely

affect nontarget organisms. EPA needs activated sludge sorption study data to assess the distribution of the antimicrobial chemical among th e solid, aqueous, and vapor phases of WWTPs. Specifically, this study identifies those chemicals which sorb to sludge biomass. Practical Utility of the Data

1. How will the data be used?

The data will be used to assess removal of the antimicrobial as a result of sorption to activated sludge. Percent removal via sorption to activated sludge and percent removal via biodegradation are used to determine overall removal of the antimicrobial during wastewater treatment. Over all removal during wastewater treatment is a key input used to determine concentrations of the antimicrobial in surface water immediately downstream of wastewater treatment plants. The concentrations of antimicrobial pesticide immediately downstream of was tewater treatment plants are used to assess exposure and risk to non

- target endangered and non

- endangered species. Exposure data are integral parts of the risk equation for determining the impact of pesticides to beneficial nontarget organisms through dir ect exposure from their

food sources and habitat.

In addition, the data will be used to determine whether or not additional studies and/or label restrictions are needed. If the data indicate that the chemical does not sorb to sludge and instead partition s more readily to

water and that the chemical does not biodegrade to an appreciable extent then the chemical has the potential to pass through the WWTP and therefore could be discharged in to the aquatic environment. This determination could trigger furth er data requirements to assess the chemical‘s impact upon release. If the data indicates relatively high potential to sorb to sludge, a screening assessment of potential exposure to ecological organimsm as a result of biosolids use and disposal would perf ormed.

2. How could the data impact the Agency’s future decision

- making?

If the data show that removal of the chemical during wastewater treatment is negligible, then the risk

assessments for this chemical would reflect the magnitude of potential risk de rived from this chemical‘s negligible removal . The risk assessment may result in the Agency requiring label restrictions that would be necessary for the products to meet the ―no unreasonable adverse effects‖ requirements of FIFRA (e.g., changes to the dir ections for disposal).

In addition, EPA is required by section 7(a)(2) of the ESA to ensure that any action it authorizes or takes ―...is not likely to jeopardize the continued existence of any endangered or threatened species or result in

the destruction o r adverse modification of critical habitat‖ and to use the best scientific data available‖ in carrying out this obligation. The data EPA intends to call in are necessary to inform the determination required by the ESA as to whether continued registration of a pesticide is not likely to jeopardize the species or its critical habitat. Absent this data EPA may not be able to conclude that this pesticide will not harm endangered species and may therefore need to consider other limitations on the use of the pe sticide in order to fulfill the Agency‘s statutory obligations under the ESA. The lack of these data will limit the flexibility that the Agency and registrants have in coming into compliance with the ESA and could result in

use restrictions which are unne cessarily severe.Page 13 of 16

Guideline Number: 850.6800; OECD 209 Study Title: Modified Activated Sludge, Respiration Inhibition Test for Sparingly Soluble Chemicals; Activated Sludge Respiration Inhibition Test
Rationale for Requiring the Data An activated sludge, respiration inhibition test (ASRI) is needed to identify whether this pesticide could harm activated sludge microorganisms found in biological wastewater treatment systems. The Agency

will use these data to determine the potential imp act of this chemical on waste water treatment plants (WWTPs) as a result of respiration inhibition of activated sludge microorganisms. This test is also necessary to enable EPA to establish correct concentrations for use in the biodegradability test, if th at test is determined to be adequate for assessing biodegradation potential. Furthermore, the results of the Activated Sludge Respiration Inhibition Test (ASRI) determine which biodegradation test is required. If

the ASRI test EC 50 is less than or equal t o 20 mg/L, then either the Biodegradation in Activated Sludge Study or the Porous Pot Test is required. If the ASRI test EC 50 is greater than 20 mg/L, then the applicant must choose either: (i) Ready Biodegradability or (ii) Biodegradation in Activated Sl udge or the Porous Pot Test. If the antimicrobial passes the ready biodegradability study, then no further testing is required. If, however, the antimicrobial fails the ready biodegradability study, then the Biodegradation in Activated Sludge or the Poro us Pot study is required.

Practical Utility of the Data

1. How will the data be used? The data will be used to assess potential adverse effects to activated sludge microorganisms. In addition,

the data will be used to determine whether or not label restrictions are needed. The study will identify the inhibitory effect of this chemical on the treatment plant‘s microorganisms‘ respiration at different concentrations of the test substance and will identify the EC 50 , the effective concentration of the t est substance at which the respiration rate is 50% of that shown by the control under conditions in this guideline. The data will also determine suitable non

- inhibitory concentrations to be used in biodegradability tests.

2. How could the data impact the Agency’s future decision

- making? If the data indicate a high degree of activated sludge respiration inhibition, a more rigorous test for biodegradation in wastewater treatment will be required than the ready biodegradability test. Also, if a high degree of respiration inhibition is demonstrated and biodegradation and/or sorption is indicated to be negligible, the Agency may require label restrictions or mitigation measures to insure that activated sludge microorganisms will not be adversely impacted.Page 14 of 16

Guideline Numbers: 835.3110, 835.3220, 835.3280 , or 835.3240 Study Titles: Ready Biodegradability, Porous Pot Test, Simulation Tests to Assess the Biodegradability of Chemicals Discharged to Wastewater ( particularly Biodegradation in Activated Sludge), or Simulation Test

– Aerobic Sewage Treatment: A. Activated Sludge Units, respectively
Rationale for Requiring the Data For antimicrobial chemicals that go down

- the

- drain and reach a WWTP, as part of its screening

- level environmental fate assessment, EPA will analyze the potential impact of the antimicrobial chemical on the microorganisms in the biological treatment processes of a WWTP. Biodegradation is an important environmental pathway in which the anti microbial is broken down by bacteria. This study results supply information on the rate of biological breakdown and the completeness of the degradation to carbon dioxide and water. A ready biodegradability study would allow the Agency to determine whether or not the chemical achieves  ̳ ̳pass levels‘‘ for ready biodegradability (e.g., 70% removal of dissolved organic carbon). The results of the Activated Sludge Respiration Inhibition Test (ASRI) determine which of these three biodegradation tests are required . If the ASRI test EC 50 is less than or equal to 20 mg/L, then either the Biodegradation in Activated Sludge Study or Simulation Test

– Aerobic Sewage Treatment: A. Activated Sludge Units or the Porous Pot Test is required. If the ASRI test EC 50 is great er than 20 mg/L, then the applicant must choose either: (i) Ready Biodegradability or (ii) Bio degradation in Activated Sludge or Simulation Test

– Aerobic Sewage Treatment: A. Activated Sludge Units or the Porous Pot Test. If the antimicrobial passes the ready biodegradability study, then no further testing is required. If, however, the antimicrobial fails the ready biodegradability study, then the Biodegradation in Activated Sludge or Simulation Test

– Aerobic Sewage Treatment: A. Activated Sludge Units, or the Porous Pot study is required. Practical Utility of the Data

1. How will the data be used? The data from a biodegradation study will be used to determine the percent removal of the antimicrobial as a result of biodegradation of the antimicrobial by activated sludge microorganisms. Percent removal via biodegradation is a key input used to determine concentrations of the antimicrobial in surface water immediately downstream of wastewater treatment plants. The concentrations of antimicrobial pestic ide immediately downstream of wastewater treatment plants are used to assess exposure and risk to non

- target endangered and non

- endangered species. Exposure data are integral parts of the risk equation for determining the impact of pesticides to beneficia l non

- target organisms through direct exposure from their

food sources and habitat.

In addition, the data will be used to determine whether or not additional studies and/or label restrictions are needed. If the chemical does not achieve a  ̳ ̳pass level‘‘ for ready biodegradability, then the Agency would determine that the chemical has the potential to pass through the WWTP and therefore may be discharged in to the aquatic environment potentially resulting in exposure to non

- target species. This

determinat ion would trigger further data requirements to assess the chemical‘s impact on the aquatic environment upon release.

2. How could the data impact the Agency’s future decision

- making? If the chemical is found to be readily biodegraded, then activated slu dge microorganisms would be identified as highly biodegradable (90% removal via biodegradation). This result would be used in conjunction with wastewater treatment plant influent volume and measurement endpoints for aquatic organisms to determine concentr ations of antimicrobial pesticide downstream of wastewater treatment plants. If high inhibition of activated sludge microorganisms (i.e., EC 50 less than or equal to 20 mg/L) is determined in an activated sludge respiration inhibition test, then higher

- tie red wastewater treatment plant (WWTP) biodegradation studies and/or an activated sludge sorption isotherm study may be triggered. If results of higher

- tier WWTP biodegradation tests indicate low or negligible removal by biodegradation, thePage 15 of 16

risk assessment s for this chemical would reflect the magnitude of potential risk derived from the chemical‘s lack of biodegradability. The risk assessment may result in the Agency requiring label restrictions that would be necessary for the products to meet the ―no unre asonable adverse effects‖ requirements of FIFRA (e.g., changes to the directions for disposal).

In addition, EPA is required by section 7(a)(2) of the ESA to ensure that any action it authorizes or takes ―...is not likely to jeopardize the continued existen ce of any endangered or threatened species or result in

the destruction or adverse modification of critical habitat‖ and to use the best scientific data available‖ in carrying out this obligation. The data EPA intends to call in are necessary to inform th e determination required by the ESA as to whether continued registration of a pesticide is not likely to jeopardize the species or its critical habitat. Absent this data EPA may not be able to conclude that this pesticide will not harm endangered species and may therefore need to consider other limitations on the use of the pesticide in order to fulfill the Agency‘s statutory obligations under the ESA. The lack of these data will limit the flexibility that the Agency and registrants have in coming into co mpliance with the ESA and could result in use restrictions which are unnecessarily severe.



## Appendix B: Ecological Guideline Study Justifications

Guideline Number: 850. 2100 Study Title: A cute avian oral toxicity
Practical Utility of the Data 1) What is the value of the study? The Agency currently does not have any acceptable acute avian oral toxicity data for ADAO . This study would allow the Agency to categorize ADAO as toxic or non

- toxic to birds. If the avian acute oral LD 50 (TGAI testing) is less than or equal to 100 mg a.i./kg, additional higher tier bird test would be needed.

2) How would the data be used? This study would be used to evaluate the toxicity of ADAO to non

- target birds in terrestrial and aquatic

ecosystems.

3) How could the data affect the risk assessment?

Adverse effects to non

- target birds in terrestrial and aquatic ecosystems may result in mitigation to protect species at risk.

4) What is triggering the need for this data? Acute avian oral toxicity stud y is required to establish the toxicity of a pesticide to birds.Page 16 of 16

Guideline Number: 850.5400 Study Title: Algal toxicity (Tier II) using freshwater green alga

, Selenastrum capricornutum
Practical Utility of the Data 1) What is the value of the study? As part of an initial risk assessment, one indicator plant species is tested for phytotoxicity. This study would allow the Agency to categorize ADAO as toxic or non

- toxic to plants. If toxic, additional higher tier plant tests would be needed. An endan gered species assessment for endangered or threatened plants is not possible without this study.

2) How would the data be used? This study would be used to evaluate the toxicity of ADAO to non

- target plants in terrestrial and aquatic

ecosystems.

3) How c ould the d ata affect the risk assessment?

Adverse effects to non

- target plants in terrestrial and aquatic ecosystems may result in mitigation to protect species at risk. Mitigation might include reduced label dosages, neutralization of effluents prior to discharge into water, restrictions on use in sensitive ecosystems or where endangered species are present, or other mitigation measures.

4) What is triggering the need for this data? Increased concern from state regulators and the public to evaluate impacts on WWTP operations, endangered species, and persistence in the environment, since initial registration, have triggered the need for this study. Green algae are critical to ecosystem health and productivity.