### Page 2 of 32 Executive Summary

Tri

- n butyl tetradecyl phosphonium chloride ( TTPC ) is an algicide, bactericide and fungic ide for use in industrial processes and water systems

. TTPC uses include water treatment in recirculating cooling systems, heat exchange water systems, air washing systems, evaporative coolers, brewery pasteurizers, pulp/paper/paperboard systems (non

- food contact paper and paperboard manufacture), and oil and gas well development and production, and enhanced oil recovery systems (non

- marine use). All product chemistry data requirements have been satisfied for this active ingredient. The Agency data base f or evaluating the environmental fate and
transport of TTPC is incomplete

. D ata gaps for this pesticide include aerobic and anaerobic aquatic metabolism, soil adsorption/desorption, activated sludge sorption isotherm, activated sludge respiration inhibitio n, and one of four waste biodegradability tests ( ready biodegradability, porous pot test, or one of two simulation tests). No ecological risk assessment

has been conducted previously for any registered TTPC uses. Based on development of exposure scenario s since registration, an ecological risk assessment will be performed for water cooling tower emissions, pulp and paper mill emissions, and oil and gas well production

emissions. TTPC is highly to very highly toxic to freshwater animals and is slightly to moderately toxic to birds. The Agency data base for evaluating the effects of TTPC and its major degradates for these uses is incomplete

. Data gaps include aquatic plant test s
, fish early life stage testing, freshwater and estuarine/marine aquatic inver tebrate life cycle test

, marine/estuarine fish, mollusk, and c rustacean acute tests

, and sediment toxicity testing with

benthic invertebrates

.

Introduction

TTPC (Table 2) is an organophosphorous ionic chemical biocide . It was first registered on Septe mber 22, 2006 as an active ingredient in Bellacide 350 / Bellacide 355 products for industrial process water treatments. Specifically, TTPC is registered to control algae, slime forming bacteria, sulfate reducing bacteria, and fungi in recirculating cooli ng tower and process

water / air washers and industrial scrubbing systems ( e.g

. , commercial and industrial cooling towers, evaporative coolers

, air washing systems equipped with a mist eliminator); heat transfer or exchange systems (e.g., dairy sweetwater systems, brewery pasteurizers, bottle and can warmers, hydrostatic sterilizers and retorts ); non

- food contact pulp, paper and paperboard
process water (e.g.

, brown paper, corrugated sheet, kraft paper, newsprint, etc.) ; enhanced oil
recovery systems (non

- m arine use and not registered for use in California) (e.g., injection and produced water systems, water disposal systems, and other oilfield water systems); oil and gas production and transmission pipelines and systems; gas storage wells and systems; hydro testing of pipelines or vessels; pipeline pigging and scraping operations; and to oil and gas well drilling and maintenance fluids, packer, completion, workover and fracturing fluids

. Uses not registered for use in California include: pulp, paper, and pap erboard systems, dairy sweetwater system applications, brewery pasteurizers, can warmers, hydrostatic sterilizers and retorts, air

- washer or air scrubber system applications and enhance oil recovery systems.

There is only one registrant for TTPC. Curren tly three products which are listed in Table

1 are registered for the uses indicated above. One product (Reg. No. 83451

- 15) is registered both as a manufacturing use product (MUP) and an end use product (EP). Applications to use

### Page 3 of 32 sites are made using a me tering

- pump system or a closed loading/application system; open pouring is prohibited

.

A Reregistration Eligibility Decision (RED) w as not issued by the Agency for TTPC because the initial registration date was after November 1984, the mandated cutoff for initiation of the RED process. In the reregistration review a n ecological risk assessment will be performed for the industrial process and water systems and oil and gas drilling, hydro testing, maintenance and oil recovery systems uses.

Table 1. Regi stere d Product of Tri

- n butyl tetradecyl phosphonium chloride

Registration

No. Registration

Name Company

Name Formulation Type % of Active 

### Ingredient

83451

- 15 B ellacide 350 BWA Water Additives US

LLC Soluble Concentrate

MUP/ EUP 50

83451

- 16 Bellacide 3 55 BWA Water Additives US

LLC Soluble Concentrate

EUP 5

83451

- 20 Bellacide 303 BWA Water Additives US

LLC Flowable Concentrate

EUP 15



### Mode of Action

The specific mode of action of quarternary alkyl phosphonium sa lts is not well

delineated. TTP C bel ongs to a group of substances that form ionic liquids (ILs) . Specifically

TTP C contains a positively charged long chain hydrocarbon, the long chain hydrocarbon is fat soluble and the charged ion portion is water

- soluble. A common supposed mechanism of ac tion

of ILs is membrane disrupt ion , resulting in leakage of cell constituents.

The Agency has conducted a review of the available product chemistry, environmental fate, and ecotoxicity data for evaluating the environmental risk from the above listed us es of TTPC and its major degradates

. The findings are summarized below.

A. Product Chemistry Summary of TTPC

A Spe c i al Note on the Chemistry of TTPC

ILs ar e a new class of compounds that show some interest ing

, and a few unique

characteristics

. S ome o f these IL chemicals were developed to advance the field of green chemistry principles ; m ost have been synthesized in the last thirty years, and have been used for various research and industrial applications.

The biggest rationale to develop these chemi cals was to find ‘alternate solvents’ in place

of more hazardous volatile organic solvents. Some characteristics of these new and modern

### Page 4 of 32 (neoteric) c hemicals include: 1) ionic in nature with a positively charged long chain hydrocarbon portion which is fat soluble and a negatively charged ion portion ; 2) negligible (low) vapor pressure; 3) low melting points, mostly under 100 o 

### C; 4) usually nonflammable; 5) low mammalian acute toxicity; and 6) some of these ‘solvents’ can init i ate reactions , particularly

w hen metal

- or enz yme

- catalyzed , that are different from the conventional solvents. Depending on the anion, ILs may or may not be water soluble.

While a number of research publications have appeared in the last 10

- 15 years about the ecotoxicity, environme ntal fate, and biodegradation properties of some quaternary ammonium and ph o sp honium ionic liquids ( Karichkhoff 1981; Wells and Coombe 2006; Lacrama et al. 2007; Pham et al. 2010; Stojanovic et al. 2011 ) , the e nvironmental fate on quaternary phosphonium is still scant.

Ecotoxicity, biodegradation, and environmental fate studies on quaternary phosphon ium ionic liquids include, but not limited to the following types: a) R

- groups attached to central phosphorous, where R = C 1 

### through C 18 

### a lkyl groups; b) mixe d alkyl groups; and c) different counter ions like chloride or bromide or more complicated like hexafluorophosphate (F 6 

### P - 

### )

.

Biodegradation studies have been conducted on quaternary phosphonium alkyl halides, (C 2 

### to C 18 

### ) alkyl groups. All studies sh ow th at none of the quaternary phosphonium ILs are ready biodegradable, particularly those that have > C 4 

### alkyl groups. None of the studies had the chemical under our consideration (TTPC). Some studies have estimated log octanol

- water partition coefficient (l og K
ow 

### ) values between 6 and 9.

Chemical identity and the physical and chemical properties of a 95% pure grade of the active ingredient and the 50% technical grade active ingredient (TG AI) and EP are provided in

the Tables 2 and 3 below. All product che mistry data requirements have been satisfied for the active ingredient T TPC . (Source: MRIDs 133035, 135035, 40680701, 40680703, 40681901, 46315602, 46333001, 46386901, 46386902, 46386903, 46466801, 46466802, 46466901, 46466902,46648601, 46648602, 46648603, 46648604, 46662101, 46662102, 46721701, 46921001, 46921002, 47912005, 47912006, and 48479001).

Table 2. Chemical Identity

Chemical Name: Tri

- n butyl tetradecyl phosphonium chloride

Phosphonium, tributyl tetradecyl

– chloride Tetradecyl tributyl phosphon ium chloride

Common Name: Tributyl tetradecyl phosphonium chloride (TTPC) Synonyms Tetra

- alkyl

- phosphonium chloride 5,6

- dibutyloctadecan

- 5

- ylphophanium chloride

IUPAC Name: Tri

- n butyl tetradecyl phosphonium chloride

PC Code: 128824

CAS Number: 81741

- 28

- 8

Molecular Formula: C 26 

### H 56 

### C Cl P

14 

### H 29 

### - P +

 ̄ 

### (C 4 

### H 9 

### ) 3 

### CH Cl ̄

3 

### (CH 2 

### ) 13 

### P(Cl)(CH 2 

### CH 2 

### CH 2 

### CH 3 

### ) 3 

### Molecular weight: 413.15 g/mole

### Page 5 of 32 Molecular Structure:

Table 3. Product Chemistry Data Summary of TTPC

OPPTS

Guideline

No. Physical and Chemical Properties TTP C (95% purity) Results TTPC (TGAI and EP, 50% purity, liquid solution) Results

830.1800 Enforcement Analytical

Method TTPC Amperometric titration. : High Performance Liquid Chromatography ( HPLC).

Lauryl sulfate, two

- phase titration method.

830.6302 Color White solid at 20°C Clear, colorless liquid at 20 ° C.

830.6303 Physical State White hygroscopic solid at room temp (20°C) Clear, colorless liquid at room
temperature ( 20 ° C )

830.6303 Odor Slightly sweet odor Very slightly sweet odor.

830.6313 Stability to sunlight,

normal and elevated temperature, metals/metal

ions Chemical stability: Using a thermal gradient of 5 °C per

minute the test material was stable through its melting point (40

- 42 °C) and up to elevated temperatures (100 °C). Reported weight los ses at very elevated temperatures were:

180 °C 2.1% weight loss 280 °C 4.5% weight loss 320 °C 6.8% weight loss Stable under normal temperature

conditions and recommended use.

The concentration of the active ingredient remains the same before

and after e xposure to the accelerated temperature conditions for 30 days at 50 ± 3 °C. For the test material packaging, there were no signs of puckering, cracking, or swelling observed supporting the

conclusion that the product and its packaging materials are stable

. There was no compromise of the

HDPE containers observed. Reactivity to Metal Ions:
Based on its chemical structure TTPC will provide a chloride ion source in the presence of moisture and may, therefore, be potentially corrosive to

metals which are su sceptible to salt solution induced corrosion (i.e., mild steels, iron, brass, copper but not

stainless steel or anti

- corrosion coated metal substrates). TTPC is not theoretically reactive with metal ions

based on its chemical structure. TTPC

is intended to be packaged in plastic drums (HDPE) and not in metal

containers.

Reactivity to Sunlight: TTPC has no UV/VIS absorption in the range 290

- 800 nm and is expected to be photolytically stable.

### Page 6 of 32 OPPTS

Guideline

No. Physical and Chemical Properties TTP C (95% purity) Results TTPC (TGAI and EP, 50% purity, liquid solution) Results

830.6314 Oxidation/ Reduction: Chemical Incompatibility Not an oxidizer or reducing agent. Does not contain oxidizing or reducing agents and TTPC has no reactive oxidizable/reducible groups in

its structure. Not an oxidizer or reducing agent. Does not contain oxidizing or reducing agents.

830.6315 Flammability: N on Flammable. Non

- flammable. Not applicable because the product is a 50% aqueous solution of an ionic solid which has no readily oxidizable functional groups in its structure and cannot, therefore, be

flammable.

830.6316 Explodability Non

- explodable. Co ntains no explosive ingredients. Not applicable because the product is a 50% aqueous solution of an ionic solid which has no readily reactive functional groups in its structure and cannot, therefore, be explosive.

830.6317 Storage Stability There was no s ignificant change in the active ingredient content of the test material during storage at 25 ± 2°C for

12 months. Accelerated Storage Stability:
The concentration of the active ingredient remains the same before and after exposure to the accelerated temper ature conditions for 30 days at 50 ± 3 °C. For the test material packaging, there were no signs of puckering, cracking, or swelling observed supporting the conclusion that the product and its packaging materials are stable. There was no compromise of the

HDPE containers observed.

There was no significant change in the active ingredient content of the test material during storage at 25 ±

2°C for 12 months.

TTPC in aqueous solution will

have a shelf life in excess of one year when stored in its non

transpare nt packaging.

830.6319 Miscibility Not applicable, because the product is not an emulsifiable liquid which is to be diluted with petroleum solvents. Not applicable, not an emulsifiable product. Not applicable for products not intended to be diluted with p etroleum solvents.

830.6320 Corrosion Characteristics Not Required

. The test material does

not exhibit corrosion / degradation of the HDPE plastic which forms the container for its packaging. Packaged in steel drums (55 kg net) with high density polyethyl ene lining. There is no evidence of

corrosion or breakdown of drums with HDPE lining. Does not attack HDPE, may slowly corrode steel or iron, and does not attack stainless

steel.

### Page 7 of 32 OPPTS

Guideline

No. Physical and Chemical Properties TTP C (95% purity) Results TTPC (TGAI and EP, 50% purity, liquid solution) Results

830.6321 Dielectric breakdown Not applicable for products not

intended to b e used around electrical equipment. Not applicable for products not

intended to be used around electrical equipment.

830.7000 pH Not applicable for solids. Undiluted: pH ranges from 7.0 to 9.0. Average pH is 7.3.

830.7050 UV/Visible absorption TTPC has n o UV/VIS absorption in the range 290

- 800 nm.

830.7100 Viscosity Not applicable for solid products. 53.6 cP at 25 °C and 15 cP at 50 °C

830.7200 Melting point 40

- 42 o Not applicable to this product because it is a liquid at room
temperature. C

830.7220 Boi ling point Not applicable because it is solid at
room temperature. 100

- 101°C

830.7300 Density 1.183 g/cc 0.95

- 1.00 g/ml at 20 °C

830.7370 Dissociation Constant Not applicable because the chemical

structure of TTPC has no dissociable groups other than the ion pair shown in the structural formula provided

below: (n

- C 4 H 9 ) 3 - P +

- C 14 H 29 Cl Not applicable to M U P or EP products.

-

830.7550 Partition coefficient ( n

octanol/water) Data gap Not applicable to M U P or EP products.

830.7840 Solubilit y in water >50% ( w/w) in water at 20 ° C Not applicable to this product because it is already an aqueous

solution.

Non guideline study Solubility in organic

solvent Methanol >50%; Isopropanol >50% ; Ethylene glycol >50% -----

830.7950 Vapor Pressure 3.75 x 10 - 8 mg Hg at 25 o

Based on the chemical structure of TTPC, the vapor pressure is estimated to be negligible as the product is an ionic solid (substituted phosphonic acid chloride salt) with a relatively large molecular weight (434.84). C (non

volatile). Not applicable to M U P or EP products.

Source: EPI

Suite Henry’s Law Constant TTPC : 6.57E

- 002 atm

- m 3

----- /mole



### B. Environmental Fate Summary

Available environmental fate guideline degradation and biodegradation studies and the

results are summarized below.

### Page 8 of 32 Degradation Studies (Abiotic)

a. Hydrolysis (161

- 1)

TTPC did not hydrolyze in sterile aqueous buffered solutions at pH 5 , 7, or 9

when incubated at 25 ° C for 3 0 days . The study is acceptable (MRID 40680702 ) 1



### b. Photodegradation in water (161

- 2)

A study (MRID 40680703) w as submitted but was not conducted according to the Agency guidelines , and was found to be unacceptable

. However, t his chemical has saturated alky groups with no double bonds (or aromatic components) present

, and these groups have no tendency to asorb in the UV /visible range (280

- 800 nm)

, so it is expected to be stable to photodegradation. In the absence of a scientifically sound study documenting otherwise, TTPC will be assumed to be stable to photolysis.

c. Octanol

- water partition coefficient (K
ow 

### ) (OCSP P 830.7550)

Octanol

- water partition coefficient (K
ow 

### ) is a very important indicator for bioaccumulative characteristic of a pesticide. The Agency requires registrants to provide the numerical value for K
ow 

### which is the ratio of the undissociated species concentration in the two phases ( n

- octanol to water) at equilibrium ; the Agency has test guidelines for the K
ow 

### determination. The test guideline s are designed to determine K
ow 

### for organic chemicals (pesticides) b y any of the three methods: 1) shake

- flask method; 2) column g enerator and 3) high

- performance liquid chromatography ( HPLC ) method. TTPC is an ionic liquid and these methods may not provide a meaningful K
ow 

### value. The K
ow 

### is usually defined as the ratio of equilibrium concentrations of the disso lved chemical in n

- octanol to that in water, and for ionic solutes the intrinsic or true K
ow 

### is for the ratio of the undissociated species in the two phases. Alternatively where measuring the undissociated species in the two phases is difficult, such as t hat expected for TTPC, the apparent K
ow 

### , measured as the ratio of the concentrations of undissociated and dissociated in the two phases at equilibrium can be used

. Ionic liquids can be water solu ble or water insoluble; either way they present difficulty

t o determine K
ow 

### values

.

1 The st udy was originally accepted by A gency scientists; the Agency reviewed it again, and has concluded that hydrolysis study for ionic substances is not applicable. However the Agency considers this data requirement as

fulfilled.

### Page 9 of 32 Biod egradation Studies ( Biotic )

a. Activated Sludge Respiration Inhibition Test ( OCSPP 850.6800 or OECD

209 )

In hibitory Effect on the Respiration of Aerobic Waste

- Water Bacteria (MRID No. 00133036): The study does not meet the curr ent guideline standards or data requirement for an activated sludge respiration inhibition test (OCSPP 850.6800 or OECD 209).

.

b. Ready Biodegradability (OCSPP 835.3110); or Porous Pot Test (OCSPP 835.3220); or Simulation Test

– Aerobic Sewage Treatment: A. Activated Sludge Units (OCSPP 835. 3240); or Simulation Tests to Assess the Biodegradability of Chemicals Discharged to Wastewater (OCSPP 835.3280)

Bioelimination in the Simulation Test

– Aerobic Sewage OECD Coupled Units Test No. 303A (MRID No. 00133037 ): The study does not meet the current guideline standards or data requirement for one of four biodegradation in wastewater system studies (OCSPP 835.3110, or 835.3220, or 835.3240, or 835.3280)

.

Test for Biodegradability of OECD Closed bottle Test No. 3 01D (MRID No. 00133038): The study does not meet the current guideline standards or data requirement for one of four biodegradation in wastewater system studies (OCSPP 835.3110, or 835.3220, or 835.3240, or 835.3280)

.

T he Agency will conduct an environme ntal fate assessment for registration review . The highly important use sites for this fate assessment are: industrial slimicides used in recirculating water cooling towers ; pulp and paper mill s ; and oil and gas drilling fluids and process waste that
poten tially pass through waste water treatment plants (WWTPs) and may be discharged into terrestrial and aquatic environments. For this assessment the Agency anticipates needing those data indicated on page 12 of this document

.

### Page 10 of 32 Water Quality

TTPC is not iden tified 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) 2 

### . In

addi tion, no Total Maximum Daily Loads (TMDL) has been developed for TTPC , based on information provided at the Agency’s National Pesticide TMDL web site (searched April 7, 2011) 3



### . More information on impaired water bodies and TMDLs can be found at http://www.epa.gov/owow/tmdl/

. The Agency invites submission of water qu ality data for this pesticide. To the extent possible, data should conform to the quality standards in Appendix A of

the OPP Standard Operating Proc edure: Inclusion of Impaired Water Body and Other Water Quality Data in OPP’s Registration Review Risk Assessment and Management Process 4 

### , in order to ensure they can be used quantitatively or qualitatively in pesticide risk assessments.

C. Ecological Eff ects Summary

No ecological risk assessment was performed for TTPC at the time of the registration.

An ecological risk assessment will be performed for the industrial process and water systems which potentially result in discharge to the aquatic environme nt as part of registration review

. Available ecotoxicity guideline studies and the results are summarized in Tables 4 & 5 for terrestrial and aquatic animals, respectively

.

a. Toxicity to Terrestrial Organisms

A summary of the available toxicity data endpoints from registrant

- submitted studies is provided in Table 4. TTPC is slightly to moderately toxic to birds. Insect pollinator data are not required based on TTPC uses . Mammalian toxicity data for evaluating exposure of mammalian

wildlife is avail able for acute oral toxicity and is discussed in the human health scoping

document.

Table 4

. Summary of the Endpoints from Submitted Terrestrial Toxicity Studies for TTPC

Study Type Species Toxicity Value (a.i.) Test
Substance Toxicity

Classification MRI D & Status

Acute

– Avian

Oral

850.2100 Mallard ( Anas platyrhynchos ) LD 50 94.3% a.i. : 232 mg/kg

- bw/day Moderately

toxic 00133051 Acceptable

Acute

– Avian Dietary

850.2200 Northern Bobwhite (Colinus virginianus ) LC 50 94.3% ai : 4214 mg/kg

- diet Slightly to xic 00133053 Acceptable

Acute

– Avian Dietary

850.2200 Mallard Duck ( Anas platyrhynchos ) LC 50 94.3% a.i. : 3663 mg/kg

- diet Slightly toxic 00133052 Acceptable

2

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

3
http://iaspub.epa.gov/tmdl_waters10/attains_nation.tmdl_pollutant_detail?p_pollutant_group_id=885&p_pollutant_ group_name=PESTICIDES

4 http://www.epa.gov/oppfead1/cb/ppdc/2006/november06/session1

- sop.pdf

### Page 11 of 32 b. Toxicity to Aquatic Organisms

A summary of acute aquatic ecotoxicity data endpoints from r egistrant

- submitted studies is provided in Table 5

. TTPC is highly to very highly acutely toxic to freshwater fish and

invertebrates. Chronic data are required but are not available. Data are not available for

sediment

- dwelling or estuarine/marine organ isms.

Table 5

. Summary of the Endpoints from Submitted Aquatic Toxicity Studies for TTPC

Study Type Species Toxicity Value (a.i.) Test
Substance Toxicity

Classification MRID & Status

Acute

– Freshwater Fish

850.1075 Rainbow trout (Oncorhynchus mykiss ) 96

- hr LC 50 49.85% a.i. : 480 μg/L H ighly toxic 00133055 Acceptable

Acute

– Freshwater Fish

850.1075 Bluegill sunfish ( Lepomis
macrochirus ) 96

- hr LC 50 49.85% a.i. : 59 μg/L Very h ighly

toxic 00133056 Acceptable

Acute

– Freshwater

Invertebrate

850.1010 W ater flea ( Daphnia

magna ) 48

- hr EC 50 49.85% a.i. : 25 μg/L Very highly

toxic 00133057 Acceptable



### c. Toxicity to Aquatic Plants

Aquatic plant data (vascular and non

- vascular species) are required for the risk

assessment . No data are available.

Adverse E cological Incidents

There are no reported incidents in the Agency's Ecological Incident Information System (EIIS) regarding TTPC. The absence of documented incidents does not necessarily mean that

such incidents did not occur.

d. Ecological Risk Assess ment

An ecological risk assessment was not conducted previously on the TTPC use patterns described

in this document. Based on development of exposure scenarios since TTPC was registered, an ecological risk assessment will be performed for water cooling t ower emissions, pulp and paper mill emissions, and oil and gas well production emissions. For this ecological risk assessment,

which will include an endangered species assessment, t he Agency anticipates needing the ecotoxicity data outlined on page 1 2 of this document

.

Environmental Fate and Ecotoxicity Data Gaps and Anticipated Work

The Agency has identified a need to conduct environmental fate

, environmental effects, and ecological risk assessments for recirculating water cooling tower emission s
, pape r mill

emission s , and oil and gas well production development emissions of TTPC and its major degradates to the environment

. The ecological risk assessment planned during registration

### Page 12 of 32 review will allow the Agency to make a “no effect” or “may affect” dete rmin ation for federally listed threatened or endangered species (listed species) and their designed critical habitats. When an assessment concludes that a pesticide’s use “may affect” a listed species or its designated critical habitat, the Agency will co nsult with the U.S. Fish and Wildlife Service and/or National Marine Fisheries Services (the Services), as appropriate.

T he Agency anticipates needing the environmental fate and ecotoxicity data bulleted

below for TTPC and/or any of its major degradation products that are of potential concern to

conduct an environmental fate and effects, and ecological risk assessment:

**•** The Agency anticipates needing the following fate data to conduct a complete

environmental fate assessment:

o Aerobic aquatic metabolism ( OCSPP 835.4300) ;

o A naerobic aquatic metabolism ( OCSPP 835.4400) ;

o Soil a dsorption/ d esorption ( OCSPP 835. 1 23 0) ;

o Modified Activated Sludge Respiration Inhibition ( OCSPP 850.6800) ;

o Activated Sludge Sorption Isotherm ( OCSPP 835.1110) ; and

o Ready biodegradability ( OCSPP 835.3110) , Porous Pot Test ( OCSPP 835.3220)

, or Simulation Tests to Assess the Biodegradability of Chemicals Discharged to

Wastewater ( OCSPP 835.3280) , or Simulation Test

– Aerobic Sewage Treatment: A. Activated Sludge Units ( OCSPP 835.3240) 5



### o Octan ol/water partition coefficient determination for TTPC by the Shake Flask

Method (OCSPP 830.7550) modified to use measure d TTPC ion pair and cation

concentrations at equilibrium .

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

o Fish early

- life stage toxicity test, freshwater species (most acutely sensitive Blue gill sunfish, Lepomis macrochirus ) (OCSPP 850.1400 )

- ;

o Aquatic invertebrate life

- cyc le, freshwater species (OCSPP 850.1300 ) ;

o Aquatic plant toxicity test, vascular species (OCSPP 850.4400 ) ;

o Aquatic plant toxicity test, non

- vascular (4 species : a freshwater green alga, a freshwater diatom, a cyanobacterium, and a marine diatom ) (OCSPP 850.5 400 ) ;

o

– Sediment chronic toxicity test, freshwater invertebrate Hyallela azteca (Special Study) ;

o Fish acute toxicity, es tuarine/marine species (OCSPP 850.1075

5 The results of the Activated Sludge Respiration Inhibition Test (ASRI) determine which of these four biodegradation tests are required. If the AS RI test EC 50 is less than or equal to 20 mg/L, then either the (i) Biodegradation in Activated Sludge Study or (ii) Simulation Test

– Aerobic Sewage Treatment: A. Activated Sludge

Units or the (iii) Porous Pot Test is required. If the ASRI test EC 50 is gr eater than 20 mg/L, then the applicant must choose either: (i) Ready Biodegradability or (ii) Biodegradation in Activated Sludge or (iii) Simulation Test

– Aerobic Sewage Treatment: A. Activated Sludge Units or (iv) the Porous Pot Test. If the antimicrobi al passes the

R eady B iodegradability study, then no further testing is required. If, however, the antimicrobial fails the R eady

B iodegradability study, then the (i) Biodegradation in Activated Sludge or (ii) Simulation Test

– Aerobic Sewage

Treatment A. A ctivated Sludge Units, or (iii) the Porous Pot study is required.

### Page 13 of 32 o Mysid acute toxicity test (OCSPP 850.1035)

o Mollusc acute toxicity (OCSPP 850.1025 or OCSPP 850.10 55)

o Mysid life

- cycle toxicity test (OCSPP 850.1350)

o Seedling emergence and growth test for rice ( Oryza sativa ) (OCSPP 850.4100);

and

o Sediment chronic toxicity test, freshwater invertebrate Chironomous dilutus (Special Study).

Facility Emissions to WWTP M odeling

For assessing the fate of TTPC and its major degradates or reaction products emitted to receiving waters from industrial process water use s of TTPC such as at pulp and paper mills, for recirculating cooling towers

, and oil and gas well developmen t the Agency anticipates using the

a vailable environmental fate information from guideline studies for TTPC and its major degradates and the following emission scenarios.

**•** Potential environmental releases and associated exposures of concern for antimicrobi al uses related to the Pulp, Paper, and Board Industry will be those identified in "Emission Scenario Documents on Pulp, Paper, and Board Industry", Number 23 of OECD Series on Emission Scenario Documents dated July 8, 2009

.

**•** Potential environmental release s and associated exposures of concern for antimicrobial

uses related to the Oil and Gas Well Production Industry will be those identified in the

latest version of the OECD Emission Scenario Document for the Oil Well Production Industry or those identified in the latest version of Generic Scenarios developed by the Chemical Engineering Branch of EPA/OCSPP/OPPT/CEB (Chemical Engineering Branch)

. On

- shore operations assume potential for disposal of drilling fluids and produce

water to public or industrial was te treatment facilities and off

- shore operations assume emissions directly to the surrounding water , post

- treatment for removal of oil

.

**•** Potential environmental releases and associated exposures of concern for uses of

antimicrobial uses related to recircula ting cooling towers will be assessed using the

Generic Scenarios for recirculating cooling towers developed by the Chemical Engineering Branch of EPA/OCSPP/OPPT/CEB and modified for use for antimicrobials by the Antimicrobial Division

.

Facility informatio n needed to estimate aquatic exposures from emissions to WWTP for each

emission scenario and directly to water from the oil and gas well development sites include the following:

**•** The number of pulp and paper mill sites using TTPC or the maximum annual produ ction volume of TTPC used in pulp and paper mills in the United States and its territories;

**•** The number of recirculating cooling tower sites using TTPC or the maximum annual production volume of TTPC used in cooling towers in the United States and its

terri tories;

### Page 14 of 32 **•** The number of oil and gas well development sites using TTPC or the maximum annual production volume of TTPC used in oil and gas well development in the United States and its territories;

**•** How many of each of these facilities have on

- site and/or of f

- site wastewater

treatment.

In the absence of information on the number of these facilities that use TTPC and how many of these facilities have on

- site and/or off

- site wastewater treatment, the Agency will

assume that all such facilities in the United St ates have the potential to use TTPC

.

In the absence of appropriate test data on biodegradation during wastewater treatment, the Agency will assume that there is no removal of TTPC and it ’ s degradates during

wastewater treatment and that the amount of TTP C released with the effluent from a wastewater treatment facility will be the same as the amount entering the wastewater treatment facility. In the absence of data on the percent removal of TTPC during drinking water treatment the Agency

will assume there is no removal of TTPC.

Default values for volume of wood treated per day ( 30 cubic meters per day for vacuum

- pressure and 15 cubic meters per day for double vacuum facilities) from the emission scenario for wood preservatives document (OECD, 2002), the w ater solubility of TTPC , and label use rate will be

used to estimate releases to WWTP in units of kilograms per day (kg/site/day).

### Page 15 of 32 D

. References

Karichkhoff, S.W. 1981. Sem i

- empirical estimation of sorption of hydrophobic pollutants on

natural sedimen ts and soils. Chemosphere 10 (8) : 833

- 846.

Lacrama, A., M.V. Putz and V. Ostafe. 2007. A spectral

- SAR model for the anionic

- cationic interaction in ionic liquids: application to Vibrio fischeri ecotoxicity. Int ernational

J ournal of Mol ecular Sci ences 8 : 842

- 863

.

Pham, T.P.T., C. Cho, and Y. Yun. 2010. Environmental fate and toxicity of ionic liquids: A

Review. Water Research 44 (2) :352

- 372.

Stojanovic, A., C. Morgenbesser, D. Kogelnig, R. Krachler, and B.K. Keppler. 2011. Chapter 26. Quaternary Amm onium and Phosphonium Ionic Liquids in Chemical and Environmental Engineering. In Kokorin, A. (editor), Ionic Liquids: Theory, Properties, New Appr oaches. InTech

. http://www.intechopen.com/books/show/title/ionic

- liquids

theory

- properties

- new

- approaches

Wells, A.S. and V. T. Coombe. 2006. On the freshwater ecotoxicity and biodegradation properties of some common ionic liquids. Organic Process Resea rch & Development. 10 (4):794

- 798.

### Page 16 of 32 

## Appendix A. Environmental Fate Study Justifications

Study Title: Sediment and Soil Adsorption/Desorption
Guideline Number 835.12 3 0
Test Substance: Pure active ingredient Rationale for Requiring the Data

A partition (or distribution) coefficient , K d , is needed to conduct the environmental fate assessment to support the TTPC uses in pulp and papermill process water systems, recirculating water cooling systems, and oil and gas well production development process system s. 

### T he data is not currently available. The Agency has a limited understanding of the potential for TTPC to partition and dispers e in the aquatic environment by means of sorption to geological materials (e.g., soil

, sediment s, organic or biological matte r) . A leaching adsorption/desorption study is

needed in order to determine the K d , which will allow the Agency to determine whether it will be tightly bound to sediments, which in turn will allow the Agency to understand the magnitude of

TTPC exposure to sediment dwelling organisms.

Controlled environmental fate and transport laboratory studies are used to determine the persistence, mobility, and bioconcentration potential of a pesticide active ingredient and its major degrad at es. The studies offer inf ormation on how, or by what mechanism, the pesticide degrades or dissipates, the rate at which it degrades or dissipates, where it goes, and what transformation products are formed. Practical Utility of the Data

1. How will the data be used?

The data w ould establish the significance of partitioning of TTPC and its major degradates to

sediment as a route of transport and dispersion. The data would also help establish the K d , the partitioning of TTPC between sediment and water in water/sediment systems

. The K d d ata from the adsorption/desorp tion study are used as inputs to exposure models. These models estimate the expected environmental concentrations of the pesticide and it ’ s degradates under various environmental and use conditions for drinking water and ecological risk assessments. The requested data will result in better characterization of TTPC mobility and will allow refined exposure estimates for drinking water and ecological risk assessments.

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

- making? In the absence of acceptable quantitative partitioning data, conservative assumptions about the pesticide’s sorption will be used. For the purposes of aquatic water column exposure modeling,

TTPC will be assumed to be highly mobile, which will lead to conservative aquatic exposure estimates that may result in unnecessary mitigation. For sediment exposure modeling, TTPC will be assumed to partition primarily to sediment, which will lead to conservative sediment exposure
estimates. If a di rect measure of the partition coefficient were available, it would be used as an input for aquatic /sediment modeling which would provide refined aquatic /sediment exposure estimates, allowing for more accurate assessments of potential risks in drinking wate r and to ecological receptors, including endangered species.

### Page 17 of 32 Study Ti tle: Aerobic Aquatic Metabolism

Guideline Number: 835.4300
Test Substance : Pure active ingredient Rationale for Requiring the Data Aerobic aquatic metabolism data is needed to con duct the environmental fate assessment to support the TTPC uses in pulp and papermill process water systems, recirculating water cooling systems, and oil and gas well production development process systems. Acceptable data on the aerobic aquatic metabolis m of
TTPC in two

- sediment systems are required. The data is not currently available. The Agency has limited understanding of how TTPC behaves in aerobic aquatic environments after discharge to receiving water. The purpose of aerobic aquatic metabolism s tudy is to determine the nature and extent of microbial degradation under aerobic conditions in receiving water/sediment systems during the dispersal of the biocide throughout the aquatic environment, and to characterize the formation and decline of degrad ates. This information will determine the persistence and concentrations of TTPC and potential degradates over the time in representative aerobic water/sediment systems. The results of the study will indicate the potential for TTPC to contaminate the aqu atic environment since biocide residues may be taken up by the sediment biota and passed on to other parts of the aquatic food web. Data are needed for two sediment

water systems conducted (one each) at neutral and acidic pHs.

Practical Utility of the D ata
1. How will the data be used? The data would establish the significance of aerobic aquatic microbial degradation of TTPC as a route of degradation and identify, if possible, the degradation products formed that may adversely affect non

- target organis ms and may contaminate water and food sources of aquatic organisms. The data would also help establish the aerobic aquatic aerobic half

- life of TTPC in water/sediment systems, and possibly it ’ s degradates, and assist in developing a degradation pathway.

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

- making? The results of this study would indicate the nature and extent of formation and decline under aerobic aquatic conditions of TTPC and it ’ s degradates that may be taken up by sediment biota a nd passed on to other parts of the aquatic food web, and facilitate s assessment of potential disposal problems. The study helps to determine the degradation rate (half

- life) of TTPC in the presence of microorganisms in different natural water/sediment sys tems and establishes what metabolites (degradates) are formed under aerobic (oxygen

- rich) conditions in the laboratory. If we do not receive this data TTPC would be assumed to be
stable to aerobic metabolism and we would not know if the chemical break s do wn leading to reduced risk

to human health or the environment or we would not know if more toxic degradates are formed leading to

increased risk to human health or the environment.

### Page 1 8 of 32 Study Ti tle: Anaerobic Aquatic Metabolism

Guideline Number: 835.4400
Test Substance : Pure active ingredient Rationale for Requiring the Data

A na erobic aquatic metabolism data is needed to conduct the environmental fate assessment to support the TTPC uses in pulp and papermill process water systems, recirculating water co oling systems, and oil and gas well production development process systems. Acceptable data on the anaerobic aquatic metabolism of
TTPC in two

- sediment systems are required. The data is not currently available. The Agency has limited understanding of ho w TTPC behaves in anaerobic aquatic environments after discharge to receiving water. The purpose of an anaerobic aquatic metabolism study is to determine the nature and extent of microbial degradation under anaerobic conditions in water/sediment systems d uring the dispersal of the biocide throughout the aquatic environment, and to characterize the formation and decline of degradates. This information will determine the persistence and concentrations of TTPC and potential degradates over time in representa tive anaerobic water/sediment systems. The results of the study will indicate the potential for TTPC to contaminate the aquatic environment since biocide residues may be taken up by the sediment biota and passed on to other parts of the aquatic food web. Additionally, anaerobic conditions are more likely to prevail where biocides are found in aquatic environments than in strictly terrestrial environments.
Data are needed for two sediment

- water systems conducted (one each) at neutral and acidic pHs.

Pra ctical Utility of the Data

1. How will t he data be used? Anaerobic aquatic metabolism data will facilitate a better understanding of the fate of TTPC residues in

water and sediment

. The data would establish the significance of anaerobic aquatic microbia l degradation of TTPC as a route of degradation and identify, if possible, the degradation products formed that may adversely affect non

- target organisms and may contaminate water and food sources of aquatic organisms. The data would also help establish th e an aerobic aqua tic microbial half

- life of TTPC in water/sediment systems, and possibly it’s degradates, and assist in developing a degradation pathway.

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

- making? The results of this study would ind icate the nature and extent of formation and decline under a na erobic aquatic conditions of TTPC and it ’ s degradates that may be taken up by sediment biota and passed on to other parts of the aquatic food web, and would facilitate assessment of potential di sposal problems. The study helps to determine the degradation rate (half

- life) of TTPC in the presence of microorganisms in different natural water/sediment systems and establishes what metabolites (degradates) are formed under anaerobic (oxygen

- poor) con ditions in the laboratory

. If the data indicate that degradation in anaerobic conditions occurs rapidly in acidic and or neutral aquatic systems and produces nontoxic transformations products, then the A gency could potentially determine that TTPC residues of concerns do not persist in these systems. If data indicate that degradation is not appreciable in aquatic systems or that transformation products are similar or higher toxicity than the parent compound, then the Agency could conclude that
TTPC residue s of concern persist in aquatic systems under anaerobic conditions. In the absence of the requested data, TTPC anaerobic aquatic metabolism half

- lives will be conservatively assumed to be stable across the environmental pH range

.

Study Title: Activa ted Sludge Sorption Isotherm
Guideline Number: 835.1110
Test Substance: Pure active ingredient Rationale for Requiring the Data Data from this study are needed to determine the sorption potential of activated sludge for the removal of specific chemica l compounds in biological wastewater treatment plants (WWTPs). No data is

### Page 19 of 32 currently available. If the chemical is not sorbed or biodegraded, then it would pass through a biological treatment system unaffected, potentially contaminating surface and drinkin g waters where it may then have the potential to adversely affect non

- target organisms. EPA needs activated sludge sorption study data to assess the distribution of the antimicrobial chemical among the solid, aqueous, and vapor phases of WWTPs. Specificall y, 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 remov al via sorption to activated sludge and percent removal via biodegradation are used to determine overall removal of the antimicrobial during wastewater treatment. Overall 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 wastewater treatment plants are used to assess exposure and risk to non

target endangered a nd non

- endangered species. Exposure data are integral parts of the risk equation for determining the impact of pesticides to beneficial nontarget 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 data indicate that the chemical does not sorb to sludge and instead partitions more readily to water and that the chemical does not biodegrade to an appreciable exte nt then the chemical has the potential to pass through the WWTP and therefore could be discharged to the aquatic environment. This determination could trigger further data requirements to assess the chemical’s impact upon release.

If the data indicates r elatively high potential to sorb to sludge, a screening assessment of potential exposure to ecological organimsm as a result of biosolids use and disposal would be performed.

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

- making?

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

assessments for this chemical would reflect the magnitude of potential risk derived from this chemical’s negligible removal . The risk assessment may result in the Ag ency 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 directions for disposal).

In addition, EPA is required by section 7(a)(2) of the ESA to en sure 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 or adverse modification of critical habitat” and to use the best scientific data availabl e” 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 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 compliance with the ESA and could result in use restrictions which are unnecessarily severe.

### Page 20 of 32 Study Title: Modified Activated Sludge, Respiration Inhibition Te st for Sparingly Soluble

Chemicals or Activated Sludge Respiration Inhibition Test
Guideline Number: 850.6800 or OECD 209 , respectively
Test Substance: Pure active ingredient Rationale for Requiring the Data An activated sludge, respiration inhibition te st (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 impact 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 that test is determined to be adequate for asses sing 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 to 20 mg/L, then either the Biodegradation in A ctivated 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 Sludge or the Porous
Pot Test. If the antimicro bial 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 Porous 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 test 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 ind icate 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 bio degradation 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 21 of 32 Study Titles: Ready Biodegradability; Porous Pot Test; or Simulation Test

– Aerobic Sewage Treatment: A. Activated Sludge Units; or Simulation Tests to Assess the Biodegradability of Chemicals Discharged to Wastewater (particularly Biod egradation in Activated Sludge)
Guideline Numbers: 835.3110 ; 83 5.3220 ; 835.3240; or 835.3280 , respectively
Test Substance: Pure active ingredient 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 wil l 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 antimicrobial is broken down by bacteria. Th ese study resu lts supply information on the rate of biological breakdown and the completeness of the degradation to carbon
dioxide and water. A R eady B iodegradability study would allow the Agency to determine whether or not the chemical achieves ‘‘pass levels’’ for read y biodegradability (e.g., 70% removal of dissolved organic carbon). The results of the Activated Sludge Respiration Inhibition Test (ASRI) determine which of these

four biodegradation tests are required. If the ASRI test EC 50 is less than or equal to 20 m g/L, then either

the (i) Biodegradation in Activated Sludge Study or (ii) Simulation Test

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

– Aerobic Sewage Treatment: A. Activated Sludge Units or (iv) the Porous Pot Test. If the antimicrobial passes the R eady B iodegradability study , then no further testing is required. If, however, the antimicrobial fails the R eady B iodegradability study, then the (i) Biodegradation in Activated Sludge or (ii) Simulation Test

– Aerobic Sewage Treatment: A. Activated Sludge Units, or (iii) the Porou s 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 pesticide

immediate ly 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 beneficial 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 bio degradability, 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
determination would tri gger 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 sludge microorga nisms 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 concentrations of ant imicrobial 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

- tiered wastewate r 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,

### Page 22 of 32 the risk assessments for this ch emical 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 unreasonable adve rse 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 existence of any end angered 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 the determinati on 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 there fore 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 compliance with the ESA and could result in use restrictions which are unnecessarily severe.

Study Title: Octanol/water partition coefficient determination for TTPC by the Shake Flask

Method
Guideline Number: 83 0. 7550 modified to measure TTPC ion pair and TTPC cation at equilibrium
Test S ubstance: Pure active ingredient Rationale for Requiring the Data The octanol/water partition coefficient (K

ow ) is a very important and fundamental chemical property . For assessing environmental fate and effects of a chemical it is used as an indicator of the bioaccumulati ve characteristic of a pesticide, as well as an indicator of toxicity to a wide variety of aquatic and terrestrial organisms

. The K

ow is usually defined as the ratio of equilibrium concentrations of the dissolved

c hemical in n

- octanol to that in water , and for ionic solutes th e intrinsic or true K

ow is for the ratio of the undissociated species in the two phases. Alternatively where measuring the undissociated species in the two phases is difficult, such as that ex pected for TTPC, the apparent K

ow 

## [ **] [**  **] (**  **)** 

## [ **] [**  **] (**  **)**

e w, e w, e o, e o, ow X M X M K **+**

**− +**  **+**

**− +**  **+ +**  **=** M M , measured as the ratio of the concentrations of undissociated and dissociated in the two phases at equilibrium can be used : ( )

.

w

here [M + ] is the cation concentration and [M + X - ] is the undissociate d ion pair concentration with the subscript o,e designating in the octanol

- phase at equilibrium and the w,e subscript designating in the

water

- phase at equilibrium.

For ILs, the p a rti ti oning coefficient has been observed to be dependent o n the initial con centration. The relationship of initial concentration to K

ow should be determined over an environmentally relevant range. A protocol for measuring the ion pair and cation at equilibrium in the two phases and determination of the

K

ow over an environmental ly relevant range is required to be submitted before conduct of the study. To facilitate the development of a protocol for K

ow determination, the following recently published paper can

be used as guidance : Sang Hyun Lee and Sun Bok Lee: 2009, J Chem Tech nol Biotechnol , 84 : 202

- 207.

### Page 23 of 32 Practical Utility of the Data

1. How will the data be used? The data from this study will be used to assess the potential for adverse effects to aquatic and terrestrial organisms from uptake and exposure through the aquati c food web. These effects include screening the bioaccumulative tendency of this chemical in aquatic organisms, and transfer to other organisms of the aquatic food web. W here a potential of concern is identified the K

ow is used to model concentrations in trophic levels of an aquatic food chain. EECs for a given trophic level are used to assess adverse effects to organisms feeding at that trophic level.

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

- making?

If K

ow from this study is > 1000, o r log K

ow is 3.2, then a full bioaccumulation fish study will be required to ascertain if bioaccumulation is persistent, that is, if depuration does not take place in 14 days after ingestion, the a label restriction for its sues around aquatic systems wil l be imposed. In the absence of this data, the Agency will assume that TTPC is bioaccumulative and will impose use restrictions for the aquatic medium.

### Page 24 of 32 

## Appendix B: Ecological Study Justifications

Study Title: Fish Early

- life Stage Toxicity Test (f reshwater species)
Guideline Number: 850.1400
Test Substance: Pure active ingredient Rationale for Requiring the Data

No fish early

- life stage toxicity test for TTPC has been submitted. The fish early

- life stage toxicity test provides the leth al and su blethal effects of a test substance on fish species. The study is necessary for

TTPC because the pesticide use patterns and environmental fate characteristics are expected to result in repeated exp osure of freshwater organisms and TTPC is expected to be p ersistent in the environment

. Without these data, the Agency is unable to evaluate the potential risks to freshwater fish and aquatic

phase amphibians (for which fish serve as surrogates) associated with chronic exposure to TTPC

. If the

test is not condu cted with the most acutely sensitive species, an acute toxicity test for the species used in the early life stage test needs to be conducted to allow calculation of an acute

- to

- chronic ratio for use in predicting an early life stage result for the most acu tely sensitive species

. Practical Utility of the Data

1. How will the data be used? The data from the fish early life stage test will be used to estimate the chronic risks to freshwater fish and amphibians associated with chronic exposures to TTPC. T he data will reduce uncertainties associated with pot ential risks to freshwater fish and amphibians thereby facilitating sound environmental management of natural resources, particularly, freshwater fisheries.

2. How could the data impact the Agency’s f uture decision

- making? In the absence of data, chronic risks would be presumed to freshwater fish/amphibians under chronic exposure conditions. T he lack of these data will limit the flexibility the Agency and registrants have in addressing risks to non

- li sted and listed species and in coming into compliance with the Endangered Species Act, and could result in use restrictions or withdrawl of uses for TTPC which may otherwise be avoided, or which are unnecessarily severe.

Study Title : Aquatic Invertebra te Life

- Cycle (freshwater species )
Guideline Number: 850.1300
Test Substance: Pure active ingredient Rationale for Requiring the Data

No chronic life cycle toxicity test for a freshwater invertebrate species ha s been submitted for TTPC. U se s of TTPC in industrial process and water systems and discharges from oil and gas well development are expected to lead to chronic expos ure of aquatic organisms due to the repeated release and transport of

TTPC from use sites into aquatic ecosystems

, and the persisten ce of TTPC. The data base for ILs is limited and insufficient to provide a sound acute

- to

- chronic ratio for estimating a chronic freshwater invertebrate

NOAEC. Without these data, the Agency is unable to evaluate the potential risks to freshwater
inverte brates associated with chronic exposure to TTPC

. T he Agency would have to presume chronic risk

to listed and non

- listed freshwater invertebrates, but would not be able to quantify the risk.

### Page 25 of 32 Practical Utility of the Data

1. How will the data be used? The aquatic invertebrate life

- cycle study would allow the Agency to analyze chronic effects, including effects on reproductive success , survival and growth, to freshwater invertebrates. The effects data would

be used to determine the likelihood that the c hronic risks can potentially impact aquatic communities, either by direct effects on invertebrates or by indirect effects on fish by reducing their food sources.

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

- making? In the absence of data, c hronic risks would be presumed to freshwater invertebrates under chronic exposure
conditions. T he lack of these data will limit the flexibility the Agency and registrants have in addressing

risks to non

- listed and listed species and in coming into complia nce with the Endangered Species Act, and

could result in use restrictions or withdrawl of uses for TTPC which may otherwise be avoided, or which are unnecessarily severe.

Study Title: Fish acute toxicity test ( estuarine/ marine species )
Guideline Numbe r: 850.1075 Test Substance: Pure active ingredient Rationale for Requiring the Data

No acute study for TTPC with an estuarine/marine fish has been submitted. Acute tests using an estuarine/marine species are required because the active ingredient is e xpected to reach estuarine/marine
environmen t s based on it ’ s use pattern s and fate, and because physiological differences which allow fish to live in an estuarine/marine environments may result in this group being more sensitive than freshwater species. W ithout these data, the Agency is unable to evaluate the potential risks to estuarine/marine fish
associated with acute exposure to TTPC

. The data base for ILs is limited and insufficient to provide a sound estimate of sensitivity of estuarine/marine speci es as compared to freshwater species. Without these data, the Agency is unable to evaluate the potential acute risks to estuarine/marine fish associated
with acute exposure to TTPC

. T he Agency would have to presume acute risk to listed and non

- listed

est uarine/marine fish

, but would not be able to quantify the risk. Practical Utility of the Data

1. How will the da ta be used?

The estuarine /marine fish acute study would allow the Agency to analyze acute lethal effects to
estuarine/marine fish from acute exposures due to TTPC use. The effects data would be used to

de termine the likelihood that the acute risks can potentially impact aquatic communities, either by direct

effects on fish or by indirect effects by reducing food resources to species that rely on fish as a food

resource

.

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

- making? In the absence of data, acute risks to marine/estuarine fish would be presumed or potentially as there are acute toxicity for a freshwater fish, applying a saf ety factor to account for the potential increased sensitivity of estuarine/marine species as compared to freshwater species

. Because t he data base for ILs is limited and insufficient to provide a sound estimate of sensitivity of estuarine/marine species a s compared to freshwater species, an approach such as applying the greatest difference found for any test

substance as a factor would be considered

. T he lack of these data will limit the flexibility the Agency and registrants have in addressing risks to n on

- listed and listed species and in coming into compliance with the Endangered Species Act, and could result in use restrictions or withdrawl of uses for TTPC which may otherwise be avoided, or which are unnecessarily severe.

### Page 26 of 32 Study Title: Estuarine/mar ine invertebrate acute toxicity test (one crustacean species (mysid) and

one mollusc (shell deposition or embryo

- larval))
Guideline Number: 850.10 3 5 for mysid ; 850.1025 or 850.1055, respectively, for mollusc Test Substance: Pure active ingredient

Rationa le for Requiring the Data

Crustacean (mysid) and mollusc (shell deposition or embryo

- larval) are representative species used to
evaluate effects for all estuarine/marine invertebrates. No acute study for TTPC with an estuarine/marine

crustacean species or with a mollusc species has been submitted. An acute test using an estuarine/marine

crustacean species and an acute test using a mollusc species are required because the active ingredient is expected to reach estuarine/marine environmen t s based on it ’ s use pattern s and fate, and because physiological differences which allow estuarine/marine invertebrates to live in an estuarine/marine environments may result in this group being more sensitive than freshwater species. Without these data, the Agency is un able to evaluate the potential risks to estuarine/marine i nvertebrates associated with

acute exposure to TTPC

. The data base for ILs is limited and insufficient to provide a sound estimate of sensitivity of estuarine/marine species as compared to freshwat er species. Without these data, the Agency is unable to evaluate the potential acute risks to estuarine/marine invertebrates associated with

acute exposure to TTPC

. T he Agency would have to presume acute risk to listed and non

- listed
estuarine/marine inv ert e brates

, but would not be able to quantify the risk.

Practical Utility of the Data

1. How will the da ta be used?

The estuarine /marine invertebrate acute stud ies would allow the Agency to analyze acute lethal effects to
estuarine/marine invertebrates from acute exposures due to TTPC use. The effects data would be used to

de termine the likelihood that the acute risks can potentially impact aquatic communities, either by direct

effects on invertebrates or by indirect effects by reducing food resources to species that rely on
invertebrates as a food resource

.

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

- making? In the absence of data, acute risks to marine/estuarine invertebrates would be presumed or potentially as

there are acute toxicit y for a freshwater invertebrate , applying a safety factor to account for the potential increased sensitivity of estuarine/marine species as compared to freshwater species

. Because t he data base for ILs is limited and insufficient to provide a sound estima te of sensitivity of estuarine/marine species as compared to freshwater species, an approach such as applying the greatest difference found for any test substance as a factor would be considered

. T he lack of these data will limit the flexibility the Agenc y and registrants have in addressing risks to non

- listed and listed species and in coming into compliance with the Endangered Species Act, and could result in use restrictions or withdrawl of uses for

TTPC which may otherwise be avoided, or which are unnec essarily severe.

Study Title : Aquatic Invertebrate Life

- Cycle ( estuarine/marine species )

Guideline Number: 850.13 5 0 Test Substance: Pure active ingredient Rationale for Requiring the Data

No chronic life cycle toxicity test for a n estuarine/marine invertebrate species ha s been submitted for

TTPC. U se s of TTPC in industrial process and water systems and discharges from oil and gas well

### Page 27 of 32 development are expected to lead to chronic exposure of estuarine/marine organisms due to the repeated

release and transport of TTPC from use sites into aquatic ecosystems, and the persistence of TTPC. The data base for ILs is limited and insufficient to provide a sound acute

- to

- chronic ratio for estimating a

chronic estuarine/marine invertebrate NOAEC. While a fresh water invertebrate life cycle and a freshwater fish early life stage test is being requested, and for which acute

- to

- chronic ratios can be derived, there can be differences between freshwater and estuarine/marine species which give rise to significantly di fferent

acute

- to

- chronic ratios. Without the estuarine/marine life

- cycle data, the Agency is unable to evaluate the potential risks to estuarine/marine invertebrates associated with chronic exposure to TTPC

. T he Agency would have to presume chronic risk to listed and non

- listed estuarine/marine invertebrates, but would not be able to quantify the risk.

Practical Utility of the Data

1. How will the data be used? The aquatic invertebrate life

- cycle study would allow the Agency to analyze chronic effect s, including effects on reproductive success , survival and growth, to estuarine/marine invertebrates. The effects data would be used to determine the likelihood that the chronic risks can potentially impact aquatic communities, either by direct effects on invertebrates or by indirect effects to organisms preying on
estuarine/marine invertebrates

.

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

- making? In the absence of data, chronic risks would be presumed to estuarine/marine invertebrates und er chronic exposure conditions. T he lack of these data will limit the flexibility the Agency and registrants have in addressing risks to non

- listed and listed species and in coming into compliance with the Endangered Species Act, and could result in use r estrictions or withdrawl of uses for TTPC which may otherwise be avoided, or which are unnecessarily severe.

Study Title: Aquatic plant growth, non

- vascular species (one freshwater green alga species, one freshwater diatom species, one estuarine/mari ne species, and one cyanobacterium species ), Tier II
Guideline Number: 850.5400

Test Substance: Pure active ingredient Rationale for Requiring the Data

No nonvascular aquatic plant toxicity data ha s been submitted for TTPC. A battery of four species,

r epresenting different morphological characteristics and environmental habitats are required for use patterns resulting in emissions to surface waters. U se s of TTPC in industrial process and water systems and discharges from oil and gas well development ar e expected to lead to exposure of aquatic organisms due to the repeated release and transport of TTPC from use sites into aquatic ecosystems, and the persistence of TTPC. For TTPC, t here is evidence in the open literature that effects to algal species may occur at or below levels resulting on impacts to microbes. Without these data, the Agency is unable to evaluate the potential risks to non

- vascular aquatic plants associated with exposure to TTPC

. T he Agenc y would have to presume risk to federally liste d and non

- listed non

- vascular plants

, but would not be able to quantify the risk.

Practical Utility of the Data

### Page 28 of 32 1. How will the data be used? The four aquatic nonvascular plant studies would allow the Agency to analyze effects on primary production

. A toxicity study on non

- vascular aquatic plant species is used to establish a dose response relationship of TTPC with primary productivity in terms of yield, growth rate, and area under the growth

curve . The effects data would be used to determine the like lihood that losses to primary production will occur and that such losses would indirectly lead to loss of other aquatic organisms through impacts such as loss of a food resource, habitat, or habitat quality

.

2. How could the data impact the Agency's fut ure decision

- making?

Because this is the only member of the 

### quaternary phosphonium class of antimicrobials currently registered in the U.S., there is no possibility of using submitted toxicity data from closely

- related surrogate chemicals to fill in potent ial data gaps. Therefore, until additional data become available, risks to aquatic non

- vascular plants (both Federally

- listed and non

- listed species) will be assumed in future

TTPC risk assessments. T he lack of these data will limit the flexibility the A gency and registrants have in addressing risks to non

- listed and listed species and in coming into compliance with the Endangered Species Act, and could result in use restrictions or withdrawl of uses for TTPC which may otherwise be avoided, or which are u nnecessarily severe.

Study Title: Aquatic plant growth, floating vascular species ( Lemna sp. ), Tier II
Guideline Number: 850.4 400

Test Substance: Pure active ingredient Rationale for Requiring the Data

No non

- rooted vascular aquatic plant toxicity data ha s been submitted for TTPC. U se s of TTPC in industrial process and water systems and discharges from oil and gas well development are expected to lead to exposure of aquatic organisms due to the repeated release and transport of TTPC from use sites into aquatic ecosystems, and the persistence of TTPC. Without these data, the Agency is unable to evaluate the potential risks to non

- rooted vascular aquatic plants associated with exposure to TTPC

.

Practical Utility of the Data

1. How will the data be used? Mats of floating non

- rooted aquatic plants provide habitat for small invertebrates, food and shelter for fish and amphibians, and food for waterfowl and marsh birds. The floating vascular aquatic plant study would

allow the Agency to evaluate ef fects to a critical component of the structure and function of the aquatic plant community. A toxicity study on a non

- rooted vascular aquatic plant species is used to establish a dose response relationship of TTPC with effects to non

- rooted aquatic plants in terms of yield, growth rate, and area under the growth curve . The effects data would be used to determine the likelihood that

losses to non

- rooted aquatic vascular plants will occur and that such losses would indirectly lead to loss of other aquatic o rganisms through impacts such as loss of a food resource, habitat, or habitat quality

.

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

- making?

Because this is the only member of the 

### quaternary phosphonium class of antimicrobials currently regi stered in the U.S., there is no possibility of using submitted toxicity data from closely

- related surrogate chemicals to fill in potential data gaps. Therefore, until additional data become available, risks

to non

- rooted vascular plants (both Federally

- li sted and non

- listed species) will be assumed in future

TTPC risk assessments. T he lack of these data will limit the flexibility the Agency and registrants have in addressing risks to non

- listed and listed species and in coming into compliance with the End angered Species Act, and could result in use restrictions or withdrawl of uses for TTPC which may otherwise be avoided, or which are unnecessarily severe.

### Page 29 of 32 Study Title: Seedling emergence and growth, rooted emergent vascular species (Rice, 

### Oryza

sativ a ), Tier II
Guideline Number: 850.41 00

Test Substance: Pure active ingredient Application method: Homogenously mixed into support media Unit of Expression: milligrams per kilogram of bulk support media (dry wt) Rationale for Requiring the Data

No seedli ng emergence and growth toxicity data for a rooted emergent vascular plant ha s been submitted
for TTPC. Sediment can be a major sink or reservoir for TTPC and its major degradates, sorbing onto organic and inorganic particles in water and depositing with them in sedimentary areas such as lakes, and
freshwater and saltwater marshes. U se s of TTPC in industrial process and water systems and discharges from oil and gas well development are expected to lead to exposure of wetland plants due to transportation, and deposition of TTPC sorbed onto particles in the waste stream from use sites , and the persistence of TTPC. Without this data, the Agency is unable to evaluate the potential risks to rooted

vascular emergent plants associated with exposure to TTPC in so il or sediment

. In the study, a minimum of four replicates are necessary to allow a nonparameteric statistical analysis, if the resulting data fail normality or homogeneity of variance assumptions.

Practical Utility of the Data

1. How will the data be used?

E mergent wetland plants, in association with soil or sediments, determine the structure and function of wetlands; they provide habitat in the form of nursery areas and cover for wildlife, and regulate the temperature and flow of water. The emergent vascular plant study would allow the Agency to analyze to a critical component of the structure and function of a n aquatic ecosystem

. A toxicity study on an emergent vascular plant species is used to establish a dose response relationship of TTPC with in terms of yield, growth rate, and area under the growth curve . The effects data would be used to determine the

likelihood that losses to emergent plants will occur and that such losses would indirectly lead to loss of other aquatic organisms through impact s such as loss of a food resource, habitat, or habitat quality

.

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

- making?

Because this is the only member of the 

### quaternary phosphonium class of antimicrobials currently registered in the U.S., the re is no possibility of using submitted toxicity data from closely

- related surrogate chemicals to fill in potential data gaps. Therefore, until additional data become available, risks

to emergent vascular plants (both Federally

- listed and non

- listed speci es) will be assumed in future TTPC
risk assessments. T he lack of these data will limit the flexibility the Agency and registrants have in addressing risks to non

- listed and listed species and in coming into compliance with the Endangered Species Act, and could result in use restrictions or withdrawl of uses for TTPC which may otherwise be avoided, or which are unnecessarily severe.

Study Title: Test Method: 100.5 Life

- cycle Test for Measuring the Effects of Sediment

- associated
Contaminants on Chironomu s dilutus (formerly known as C. tentans )
Guideline Number: Agency

- wide guideline USEPA 2000b ; Non

- 850 guideline , Special Study Exposure Method: Spiked whole sediment
Test Substance: Pure active ingredient Rationale for Requiring the Data

No chronic sp iked

- sediment toxicity test for a freshwater benthic emergent insect ha s been submitted for

TTPC. Use of TTPC in industrial processes and water systems and oil and gas well production systems may result in the active ingredient reaching aquatic sediments. Sediment benthos may be exposed to

### Page 30 of 32 s ediment associated chemicals via pathways not accounted for in water only studies , such as ingestion of

sediment

. Chemicals that partition to sediment and are persistent in the sediment have the potential to pose a chr onic risk to sediment benthos. TTPC is assumed to partition to sediment and be persistent given the following:

o The half

- life of TTPC in aerobic and anaerobic soils is expected to be greater than 10 days based

on half

- life of other ILs ; and

o The organic c arbon partitioning coefficient, Koc, of the hydrophilic portion of TTPC is expected
to be >1000

. For freshwater sediment studies, chronic tests on a benthic emergent insect ( Chironomus dilutes, formerly

Chironomus tentans ) and an amphipod ( Hyalella azteca ) are requested. Although both are freshwater species, Hyalella and Chironomus differ substantially in their ecological niche ( i.e ., infaunal species versus epibenthic), physiology, and potential sensitivities to TTPC exposure. Prior to conduct of the

stu dy, the test design and protocol must be submitted for Agency review and approval. If the half

- life is found to be <10 days in both aerobic and anaerobic aquatic sediment metabolism studies a 10

- day survival and growth study for this species using public draft 850.1735 Whole Sediment Acute Toxicity Invertebrates, Freshwater. Prior to conduct of the study, the test design and protocol must be submitted for Agency review and approval as the there are changes in recommended testing guidance from that provide d in the public draft. Practical Utility of the Data

1. How will the data be used? Data from sediment toxicity studies will be used to estimate potential risks to benthic organisms
associated with uses of TTPC

. Data from sediment toxicity studies will be compared to estimated sediment chronic exposure concentrations to evaluate the potential for TTPC to adversely impact survival, emergence, reproduction, and growth of sediment invertebrates.

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

- mak ing? If the data indicates that registered TTPC usage may pose a risk of adverse effects to non

- target benthic organisms above the Agency Level of Concern, the Agency may explore decision options to mitigate this
risk. T he lack of these data will limit t he flexibility the Agency and registrants have in coming into compliance with the Endangered Species Act, and could result in use restrictions for TTPC which may otherwise be avoided, or which are unnecessarily severe.

Study Title: Test Method: 100.4: H yalella azteca 42

- d test for Measuring the Effects of Sediment Associated Contaminants on survival, Growth, and Reproduction
Guideline Number: Agency

- wide guideline USEPA 2000b ; Non

- 850 guideline , Special Study Exposure Method: Spiked whole sediment

Test Substance: Pure active ingredient Rationale for Requiring the Data

No chronic spiked

- sediment toxicity test for a freshwater benthic amphipod ha s been submitted for TTPC. Use of TTPC in industrial processes and water systems and oil and gas well product ion systems may result in the active ingredient reaching aquatic sediments. Sediment benthos may be exposed to s ediment associated chemicals via pathways not accounted for in water only studies , such as ingestion of sediment

. Chemicals that partition to s ediment and are persistent in the sediment have the potential to pose a chronic
risk to sediment benthos. TTPC is assumed to partition to sediment and be persistent given the following:

o The half

- life of TTPC in aerobic and anaerobic soils is expected to be greater than 10 days based

on half

- life of other ILs ; and

o The organic carbon partitioning coefficient, K

oc

For freshwater sediment studies, chronic tests on a benthic emergent insect ( Chirono mus dilutes, formerly , of the hydrophilic portion of TTPC is expected

to be >1000

.

### Page 31 of 32 Chironomus tentans ) and an amphipod ( Hyalella azteca ) are requested. Although both are freshwater species, Hyalella and Chironomus differ substantially in their ecological niche ( i.e ., infaunal species versus epibenthic), physiology, and potential sensitivities to TTPC exposure. Prior to conduct of the study, the test design and protocol must be submitted for Agency review and approval. If the half

- life is found to be <10 days in both aerobic and anaerobic aquatic sediment metabolis m studies a 10

- day survival and growth study for this species using public draft 850. 1735 Whole Sediment Acute Toxicity Invertebrates, Freshwater. Prior to conduct of the study, the test design and protocol must be submitted for Agency review and approval as the there are changes in recommended testing guidance from that provided in the public draft. Practical Utility of the Data

1. How will the data be used? Data from sediment toxicity studies will be used to estimate potential risks to benthic organis ms associated with uses of TTPC. Data from sediment toxicity studies will be compared to estimated sediment chronic exposure concentrations to evaluate the potential for TTPC to adversely impact survival, emergence, reproduction, and growth of sediment in vertebrates.

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

- making? If the data indicates that registered TTPC usage may pose a risk of adverse effects to non

- target benthic organisms above the Agency Level of Concern, the Agency may explore d ecision options to mitigate this
risk. T he lack of these data will limit the flexibility the Agency and registrants have in coming into compliance with the Endangered Species Act, and could result in use restrictions for TTPC which may
otherwise be avoide d, or which are unnecessarily severe.

Study Title: Methods for Assessing the Chronic Toxicity of Marine and Estuarine Sediment

Associated Contaminants with the Amphipod Leptocheirus plumulosus
Guideline Number: Agency

- wide guideline USEPA 2001c; Non

- 8 50 guideline , Special Study Exposure Method : Spiked whole sediment
Test Substance: Pure active ingredient Rationale for Requiring the Data

No chronic spiked

- sediment toxicity test for an estuarine/marine benthic amphipod ha s been submitted for

TTPC. Use of TTPC in industrial processes and water systems and oil and gas well production systems may result in the active ingredient reaching aquatic estuarine/marine sediments. Sediment benthos may be exposed to s ediment associated chemicals via pathways not a ccounted for in water only studies , such as ingestion of sediment

. Chemicals that partition to sediment and are persistent in the sediment have the potential to pose a chronic risk to sediment benthos. TTPC is assumed to partition to sediment and be persi stent given the following:

o The half

- life of TTPC in aerobic and anaerobic soils is expected to be greater than 10 days based

on half

- life of other ILs ; and

o The organic carbon partitioning coefficient, Koc, of the hydrophilic portion of TTPC is expected

t o be >1000

. Prior to conduct of the study, the test design and protocol must be submitted for Agency review and approval. If the half

- life is found to be <10 days in both aerobic and anaerobic aquatic sediment
metabolism studies a 10

- day survival and grow th study for this species using public draft 850.17 40 Whole Sediment Acute Toxicity Invertebrates, Freshwater. Prior to conduct of the study, the test design and protocol must be submitted for Agency review and approval as the there are changes in recomme nded testing guidance from that provided in the public draft. Practical Utility of the Data

1. How will the data be used? Data from sediment toxicity studies will be used to estimate potential risks to benthic organisms
associated with uses of TTPC. Da ta from sediment toxicity studies will be compared to estimated

### Page 32 of 32 sediment chronic exposure concentrations to evaluate the potential for TTPC to adversely impact survival, emergence, reproduction, and growth of sediment invertebrates.

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

- making? If the data indicates that registered TTPC usage may pose a risk of adverse effects to non

- target benthic organisms above the Agency Level of Concern, the Agency may explore decision options to mitigate this

ris k. T he lack of these data will limit the flexibility the Agency and registrants have in coming into compliance with the Endangered Species Act, and could result in use restrictions for TTPC which may otherwise be avoided, or which are unnecessarily severe

.