**...\.~EO Sl'-4~** 

### .~~**~c$\. ~**  

# U UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

S 

# m WASHINGTON D.C., 20460

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# <i 'If**~ ~** 

## ~**f\~**

## ~i.**PRO'1~(i**

MEMORANDUM

SUBJECT:

FROM:

THRU:

TO: OFFICE OF CHEMICAL SAFETY

AND POLLUTION PREVENTION



### March 16,2012

Product Chemistry, Environmenta l Fate, and Ecological Effects Scoping

Document in Support of Registrat ion Review of Methyloxazolidines

PC Codes: DP Barcode: 394305 4,4-dimethyloxazolidine: 114801

3

, 4

, 4

- Trimeth y loxazolidine : 114802

Decision No.: 455124 Re g istration Nos.: See A pp endix A Table 1

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

Environmental Scoping Document for

Re g istration Review

Risk Assessment Type: Multiple Case No.: 3095

chemicals

TXRNo.:NA CAS Nos.: 4,4-Dimethyloxazolidine: 51200 -87-4;

and 3,4,4- Trimeth y Joxazolidine : 75673 -43-7

MRID No.: See Tables 1,2

, 3 and 4 & 

### 40 CFR : None

pg.nos. 8,9,10,11,12,13,14,15, 18, 19,20

Srinivas Gowda, Microbiologis t/ Science

## Coord**~~ ~~~**  

# o..5t**~Q..** James Breithaupt, Agronomist

### y~,~-, 

# --

Zoe Layton, Biologist

### ~ Risk Assessment and Sc · c u ort Branch (RASSB)

Antimicrobials Division P)



### Nader Elkassabany, PhD, Branch Chief 

# vfla.b

# ~**~** Donna Randall, Ecological Risk Assessment Team Lead

# ~I Risk Assessment and Science Support Branch (RASSB) 

# --l

Antimicrobials Division (751OP)

Mark Hartman, Branch Chief

Lance Wormell, Team Leader

Seiichi Murasaki, Chemical Review Manager Regulatory Management Branch II

Antimicrobials Division (751 OP)

Page 1 of40

### Page 2 of 40 (This page is intentionally left blank.)

### Page 3 of 40 

## Contents

Executive Summary

................................ ................................ ................................ ........................ 4

1. Introduction

................................ ................................ ................................ ............................. 7

2. Product Chemi stry Summary

................................ ................................ ................................ .. 7

3. Environmental Fate Summary

................................ ................................ ................................ . 8

4. W ater Quality Summary

................................ ................................ ................................ ........ 10

5. Ecological Effects Summary

................................ ................................ ................................ . 10

5.1. Toxicity to Birds, Acute and Subacute

................................ ................................ ........... 10

5.2. Toxicity to Freshwater Aquatic Animals

................................ ................................ ........ 12

5.3. Toxicity to Estuarine and Marine Animals

................................ ................................ ..... 14

5.4. Toxicity to Aquatic Plants

................................ ................................ .............................. 15

5.5. Toxicity of Degradation Products

................................ ................................ ................... 15

5.5.1.1. Toxicity to Avian Species

................................ ................................ .................... 15

5.5.1.2. Toxicity to Freshwater Fish and Invertebrates

................................ ..................... 16

5.5.1.3. Toxicity to Estuarine/Marine Fish and Invertebrates

................................ ........... 17

5.5.1.4. Toxicity to Aquatic Plants

................................ ................................ ................... 18

6. Facility Emissions to WWTP Modeling

................................ ................................ ................ 20

7. Environmental Fate and Ecotoxicity Data Gaps and Anticipated Work

............................... 22

TABLE 1. Ecotoxicity Data Summary for DMO

................................ ................................ ................................ ...... 11

TABLE 2. Ecotoxicity Data Summary for EP (BiobanTM CS

- 1135)

................................ ................................ ........ 12

TABLE 3. Ecotoxicity Data Summary for AMP

................................ ................................ ................................ ....... 16

TABLE 4. Ecotoxicity Data Summary for Formaldehyde

................................ ................................ ........................ 18

### Page 4 of 40 

## Executive Summary

Methyloxazolidines

, case 3095

, consists of two active ingredients 4,4

- dimethyloxazolidine (DMO) (PC Code 114801) and 3,4,4

- trimethyloxazolidine (PC Code 114802). H owever, one of these active ingredients

— 3,4,4

- t rime thyloxazolidine , does not currently have any registered products. Because t his active ingredient is not being supported it is not addressed in this registration revie w; during this time if a registrant were to seek a registration of an end

- use product with this active it would require a new use active ingredient assessment

. DMO is the only active ingredient reviewed in the methyloxazolidines registration review case.

DMO is a water soluble, liquid organic biocide, registered for use a s a material preservative for the protecti on of caulks, sealants, grouts, spackling, ready

- mixed wallboard compounds,

water

- based resin emulsions, metalworking cutting fluids, latex paints, adhesives, inks, dispersed colors and ready

- mixed joint cements against microbial deterioration and as a

mic robiocide and bacteriostat additive in laundry detergents and cleansers

, industrial process water systems, secondary oil recovery injection water and oil recovery drill muds. DMO

was first registered in the United States in October 1982 for use as an industrial preservative for metalworking fluids, latex paints and resin emulsions. A Reregistration Eligibility Decision (RED) for 4,4

- Dimethyloxazolidine was completed in August 1996. Hazards were

characterize d as part of the assessment but no quantitative risk assessment was performed.

To address these hazards labels for DMO products require that discharges to aquatic environments comply with a National Pollutant Discharge Elimination System (NPDES) permit an d wastes be disposed of appropriately. Currently there are three companies with a

total of six products

— all are end

- use products. All product chemistry data requirements

have been satisfied for th is active ingredient.

As part of the registration review p rocess, risk assessments for those DMO use patterns resulting in discharge of DMO and its major degradates of concern to water will be

conducted. DMO degrades rapidly by hydrolysis in minutes to form 2

- amino

- 2

- methyl

- 1

- propanol (AMP, CAS No. 124

- 68

- 5), wh ich is stable to abiotic degradation processes. Because DMO is hydrolyzed so rapidly to AMP and formaldehyde , photodegradation of DMO in water is not a significant route of degradation. The Agency's in

- house database does not have any acceptable environm ental fate and transport data on the degradate, AMP. These data are required to assess environmental fate for the registered use patterns that may potentially enter waste water treatment plants (WWTPs) and subsequently be discharged to aquatic environments

.

AMP is on the 2007 Organization for Economic Co

- operation and Development (OECD) list of high production volume (HPV) chemicals 1 

### for which a Screening Information Data Set (S IDS) Initial Assessment Report was scheduled to be performed. As part of this effort

a Robust Sum mary of d ata 2

1 The 2007 OECD List of High Production Volume Chemicals, Series on Testing and Assessment, Number 112,23

October 2009 

### has been submi tted to the Agency. The letter submitted with the Robust Summary contained a request from Dow for AMP to be removed from the

2 letter dated 8/28/2011 from The Dow Chemical Company to Mark Townsend, Chief, HPV Chemicals Branch of

EPA/OCSPP/OPPT

### Page 5 of 40 International Council of Chemical Associations (ICCA) Program and brought back to t he EPA HPV Challenge Program.

An examination of the chemical structure and a review of information in this Robust Summary for AMP

, indicate s that a high percentage of AMP may be removed by conventional sewage treatment systems. Specifically, the biodegrad atio n of AMP has been

demonstrated in a lab oratory ready biodegradability study to remove 89% of the biochemical oxygen demand ( B OD ) in 28 days under aerobic conditions, using non

- adapted

domest ic activated sludge inoculum (OECD Guideline test 301F)

. The primary removal

mechanism was attributed to mineralization.

To be able to give merit to this claim, the Agency need s to review and evaluate the primary references cited in this letter to the Agency. Without reviewing and evaluating these primary

refer ences and reaching the same conclusions as those presented, the Agency anticipates needing

environmenta l fate data from tests:

**•** Activated Sludge Sorption Isotherm (GLN 835.1110);

**•** Anaerobic aquatic metabolism for the degradate AMP (GLN 835.440 );

**•** Aerobic aqu atic metabolism for the degradate AMP (GLN 835.4300 );

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

– Ae robic Sewage Treatment: A. Activated Sludge

Units (GLN 835.3240) for AMP

.

With the exception of one avian oral toxicity study on a waterfowl species (OCSPP Guideline 850.2100), the ecotoxicological database is adequate to characterize the hazards from acute toxicity of DMO to nontarget terrestrial and aquatic organisms. However, there is a lack of data for assessing risk from the major degra date, AMP, which is the form exposure will occur for nontarget organisms. The Agency anticipates needing the fol lowing ecotoxicity data in order to conduct a complete ecological risk assessment, including an endangered species determination :

o Activated Sludge Respiration Inhibition for AMP ( GLN 850.6 800 or OECD 209) ;

o Avian acute oral toxicity test, using the bobwhite quail for AMP (OCSPP 850.2100) ;

o Freshwater fish acute toxicity, most a.i. sensitive species the bluegill sunfish

— major degradation product, AMP (OCSPP 850.1075);

o Fish early

- life stage toxicity test, freshwater species with the same species acute

t oxicity is conducted on (bluegill sunfish)

— major degradation product, AMP (OCSPP 850.1400) ;

o Freshwater invertebrate acute toxicity, Daphnia magna

— major degradation product, AMP (OCSPP 850.1010);

o Aquatic invertebrate life

- cycle, freshwater Daphnia magna

— ma jor degradation product, AMP (OCSPP 850.13 0 0) ;

o Estuarine/marine fish acute toxicity study

— major degradation product, AMP (OCSPP 850.1075);

o Estuarine/marine invertebrate acute toxicity using the saltwater mysid

— major degradation product, AMP (OCSPP 850.103 5);

### Page 6 of 40 o Mollusk embyro larvae or shell deposition study

— major degradation product, AMP (OCSPP 850.1055 or 850. 1025 );

o Aquatic invertebrate life

- cycle, saltwater Americamysis bahia

— major degradation product, AMP (OCSPP 850.13 5 0) ;

o Seedling emergence (Tier II) with rice

— major degradation product, AMP (OCSPP 850.4225);

o Aquatic plant toxicity test using Lemna spp.

— major degradation product, AMP (OCSPP 850.4400);

o Algal toxicity (Tier II) for four species

— major degradation product, AMP (OCSPP 850.5400).

### Page 7 of 40 

## 1. Introdu ction

4,4

- Dimethyloxazolidine (DMO) was initially registered as a pesticide in the United State s in

October 1982 for use as a microbiocide and bacteriostat industrial preservative for metalworking fluids, latex paints and resin emulsions. Currently it is used in six products ( Appendix A Table 1) . It is used as a materials preservative in such products as c aulks, sealants, grouts, spackling, ready

- mixed wallboard compounds, resin emulsions, latex paints, adhe sives, inks, resin emulsions, dispersed colors, ready

- mixed joint cements, metalworking cutting fluids, lubricants and mold release agents in plastic manufacturing, mineral slurries, dishwashing liquids, surface cleaners, laundry cleaners, polishes , home care cleaning products including floor cleaners, waxes, polishes and surface cleaners; laundry additives including liquid laundry detergents,

fabric softeners , and stain removers . It is also used in i ndustrial processes and water systems such as gas/oil recovery injection systems, non

- marine enhanced oi l recovery systems, oil field

water systems

, metal working fluids, preserving drilling muds , workover and completion fluids, polymer of micellar floods, water

- disposal systems or other oil field water systems ( Appendix A

Table s 2 and 3)

. A Reregistration E ligibility Decision (RED) was issued by EPA for DMO in August 1996 3



### .

There are two active ingredients in the Methyloxazolidines case 3095; however, one of these active ingredients, 3,4,4

- Trimethyloxazolidine (PC Code 114802), does not have registered prod ucts. This chemical is not being supported and is not addressed in this registration review.

DMO is the only active ingredients in the case with active products.

The Agency has conducted a review of the available product chemistry, environmental fate, and ecotoxicity data for DMO

. The primary source of information for this assessment was the 199 6

DMO RED. The findings are summarized below.



## 2. Product Chemistry Summary of DMO ( 78 % Liquid )

Common Name: 4,4

- Dimethyloxazolidine (DMO)

Chemical Name: 4,4

- Dimethyloxazolidine

OPP Chemical Code: 114801 CAS Registry Number: 51200

- 87

- 4

Trade Names: Bioban CS

- 1135; Nuosept 101; Cosan 101;Troysan 192

Molecular Formula: C 5 

### H 11 

### N O Molecular weight: 101.14 g/mole

Molecular Structure:

Color: Colorless to slightly yellow liquid.

3 http://www.epa.gov/oppsrrd1/REDs/3095red.pdf

### Page 8 of 40 Physical State: Liquid

. Odor: An amine odor (fishy)

. Stability: Stable under ambient conditions. It does not react with steel

or iron. pH: 10.5 to 11.5 (78% liquid )

11.0 (0.1 M aqueous solution of pure active ingredient (PAI) ) UV/Visible absorption: The absorption maxima determined at acidic pH levels less than 2, neutral pH at 7.61 and a basic pH level greater than

10 were 202

- 203, 203 and 207 nm, respectively. Viscosity: 7.4 centipoise at 25°C

. Melting point: Not require d for liquid s

. Boiling Point: 100.9°C

. Density: 0.924 g/ml (PAI)

. Bulk Density: 0.99 g/ml

. Dissociation Constant s in

W ater : pKa = 9.35 at 25°C. Log K o/w 

### : log P = 0.73

Solubilit ies : Miscible with water in all proportions. It is also miscible with methanol, ethanol, propanol, and acetone. Vapor Pressure: 7.58 mm Hg (Source: EPI Suite)

. 100 mm Hg at 70

- 72°C.

The 78% concentrate is a solution in water. Its vapor pressure is the combination of pressures from the active ingredient and its solvent, water. Henry's Law Constant: 1.009E

- 006 atm

- m 3 

### /mole at 25 ° C ( Source: EPI Suite)

. Enf orcement Analytical

Method: Gas chromatography

.

All product chemistry data requirements have been satisfied for the active ingredient DMO (S ource: MRID s 42941000, 42941001, 43328100, and 43328101 , 443115

- 01 )

.



## 3. Environmental Fate Summary

The only environmental fate data submitted for DMO are hydrolysis and photodegradation in water. Acceptable studies were conducted for both data requirements (MRID 41664801 for hyd rolysis and 41964701 for photodeg radation in water).

In the hydrolysis study, DMO apparently hydrolyzed in a matter of minutes at pHs of 5, 7, or 9,

and no definitive rate or half

- life could be determined from the study. Only a small amount of
parent DMO (21

- 43 ppm, 8.4

- 17 % of initial ) was present soon after solution preparation ( time =0 samples) and throughout the study. The hydrolysis products were formaldehyde and

AMP , and AMP was stable for the length of the hydrolysis study (32 days). AMP was present at time=0 samples in concentrations of 207

- 229 ppm (83

- 91.6 % of dosing rate) (MRID 41664801).

### Page 9 of 40 Photolysis in water is not a significant route of dissipation for DMO . In the photolysis in water study, the same pattern of degrada tion was observed. DMO apparently hydrolyzed in a matter of minutes in both the dark control and irradiated samples at pH 7, and no rate or half

- life could be determined from the study. Only a small amount of parent DMO (23.4

- 24.4 ppm, 9.5

- 10.7 % of

initi al ) was present soon after solution preparation (time=0 samples) and throughout the study. The hydrolysis products were formaldehyde and AMP , and AMP was stable for the length of the photolysis study (6 days). AMP was present at time=0 samples in concentra tions of 220

- 223 ppm (89.3

- 90.5 % of dosing rate) (MRID 41960701).

DMO degrades rapidly by hydrolysis in minutes to form AMP , which is stable to abiotic degradation processes. Because DMO is hydrolyzed so rapidly to AMP, photodegradation

of DMO in water is not a significant route of degradation. The Agency's in

- house database does not have any acceptable environmental fate and transport data on the degradate, AMP. These data are required to assess environmental fate for the registered use patterns that m ay potentially enter waste water treatment plants (WWTPs) and subsequently be discharged to aquatic environments.

AMP is on the 2007 Organization for Economic Co

- operation and Development (OECD) list of high production volume (HPV) chemicals 4 

### for which a Screening Information Data Set (S IDS) Initial Assessment Report was scheduled to be performed. A Robust Summary

of data 5



### An examination of the chemical structure and a review of information in this Robust Summary for AMP indicate that a high percentage of AMP may be removed by

con ventional sewage treatment systems. Specifically, the biodegradation of AMP has been

demon strated in a laboratory ready biodegradability study to remove 89% of the biochemical oxygen demand ( BOD ) in 28 days under aerobic conditions, using non

- adapted

dom e stic activated sludge inoculum (OECD Guideline test 301F)

. The primary removal

mechanism was attributed to mineralization. has been submitted to the Agency. This Summary Report contained a letter
request ing from Dow to be removed from the International Cou ncil of Chemical Associations (ICCA) Program and brought back to the EPA HPV Challenge Program.

To be able to give merit to this claim, the Agency would need to review and evaluate the primary

references cited in this letter to the Agency. Without reviewing and evaluating these primary references and reaching the same conclusions as those presented, the Agency anticipates needing

environmental fate data from tests including the activated sludge respiration inhibition (ASRI)

test and depending on the outcome of the ASRI test, either a ready biodegradability test or one of the following simulation tests: porous pot test, or simulation tests to assess the biodegradability of chemicals discharged in wastewater, or simulation test

- a erobic sewage treatment: A. Activated Sludge Units.

4 The 2007 OECD List of Hig h Production Volume Chemicals, Series on Testing and Assessment, Number 112,23

October 2009

. 5 letter dated 8/28/2011 from The Dow Chemical Company to Mark Townsend, Chief, HPV Chemicals Branch of

EPA/OCSPP/OPPT

### Page 10 of 40 

## 4. Water Quality

DMO 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 ) 6 

### . In addition, no Total Maximum Daily Loads (TMDL) have been developed for DMO , based on information provided at the Agency’s National Pesticide TMDL web site (searched April 7, 2011) 7 

### . More information on impaired water bodies and TMDLs can be found at http://www.epa.gov/owow/tmdl/ . The Agency invites submission of water quality data for this pesticide. To the extent possible, data should conform to the quality standards in Appendix A of

the OPP Standard Operating Procedure: Inclusion of Impaired Water Body and Other Water Quality Data in OPP’s Registration Review Risk Assessment and Management Process (see: http://www.epa.gov/oppfead1/cb/ppdc/2006/november06/session1

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



## 5. Ecological Effects Summary

I n A ugust of 1996 the US EPA completed its RED on the DMO case. It was determined that the ecotoxicological data base (Table 1 ) was adequate to characterize the acute toxicity of DMO to nontarget terrestrial and aquatic organisms when used to control pests in aquatic or terrestrial industrial and indoor nonfood sties. Subsequently, data were called in to Troy, Dow, and International Specialty on October 16 th 

### , 1996. No quantitative ecological risk assessment was performed for DMO at the time of the RED

. In the registration review a quantitative ecological risk assessment will be conducted for use patterns which result in discharges of the parent or degradates of concern to aquatic systems ( i.e . metalworking fluids

, industrial water process systems, oil we ll treatment and drilling muds

, and consumer product uses ). Because DMO rapidly hydrolyzes to AMP and formaldehyde , it is necessary that risk assessments focus on the degradate s rather than the parent. Available ecotoxicity guideline studies and the resu lts are

summarized in Tables 1 and 2

. Ecotoxicity studies with the major degradation products, formaldehyde and AMP, are summarized in Tables 3 and 4

.



### 5.1. **Toxicity to Birds, Acute and Subacute**

There are two avian acute oral toxicity studies, one (MRID 42967 201) with a waterfowl species the mallard duck ( Anas platyrhynchos ) and the other with a gamebird species (MRID 0076970), bobwhite quail ( Colinus virginianus ) (Table 1)

. T he test performed on the mallard duck (MRID 0076970) was categorized as “supplementa l” but the bobwhite quail study is classified as acceptable and provides a definitive acute oral LD 50 

### value

. The bobwhite quail were more sensitive to DMO than the mallard duck on an acute oral

basis. There is also sub

- acute dietary studies with both species and in both studies the highest DMO concentration in the diet were below the LC 50 

### so no definitive LC 50 

### value

6

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

7
http://iaspub.epa.gov/tmdl_waters10/attains_nation.tmdl_pollutant_detail?p_pollutant_group_id=885&p_pollutant_ group_name=PESTICIDES

### Page 11 of 40 could be established. While the highest concentration tested in both studies were below the guideline standard of 5000 ppm

- diet for a limit test, the studies were classified as acceptable. Because DMO rapidly hydrolyzes, exposure of nontarget avia n species to DMO from registered use patterns is not expected and therefore this information is acceptable and no further testing is required for registration review.

No other avian tests have been submitted to th e Agency since the 1996 RED. It is not

ne cessary to call in an avian reproduction study at this time for DMO ; based on the fate properties discussed above as birds are not expected to be subjected to repeated or continued exposure to DMO

.

T ABLE 1 . Ecotoxicity Data Summary for DMO

MRID No Guidel ine Common

Name Taxonomic

Name Test Type % a.i. Study

Duration Endpoint Toxicity Units Status Tox. Category

42967201 850.2100 Bobwhite Quail Colinus virginianus O 76% 14 D LD 50 705 mg/kg

bw Acceptable Slightly toxic

76970 850.2100 Mallard Duck Anas platyrhynchos O 78% 14 D LD 50 >1105 mg/kg

bw Supplemental Moderately toxic

102975 71

- 2a Bobwhite Quail Colinus virginianus D 78% 8 D LC 50 >3250 ppm Acceptable Slightly toxic

102976 71

- 2b Mallard Duck Anas platyrhynchos D 78% 8 D LC 50 >4008 ppm Acceptable Slightly toxic

68770 850.1075 Rainbow Trout Oncorhynchus mykiss S Tech 96 hr LC 50 95 ppm Supplemental (Downgraded) Slightly toxic

76969 850.1075 Bluegill

Sunfish Lepomis

macrochirus S 77% 96 hr LC 50 59 ppm Supplemental (Downgraded) Slightly toxic

Freshwater Invertebrate Acute Toxicity

76968 850.1010 Water Flea Daphnia

magna S 77% 48 hr EC 50 45 ppm Supplemental (Downgraded) Slightly toxic

102974 850.1075 Sheepshead

Minnow Cyprinodon variegatus S 82% 96 hr LC 50 218 ppm Supplemental (Downgraded) Practically non

toxic

76967 850.1035 Pink Shrimp Penaeus

duorarum S 77% 96 hr LC 50 230 ppm Supplemental (Downgraded) Practically non

toxic

102973 850.1025 Eastern Oyster Crassostrea virginica F 83% 96 hr EC 50 9.2 ppm Acceptable Moderately toxic

Test Type

— O: oral; D: dietary; S: static; F: flow

- through. Units

— mg/kg

- bw : milligrams per kilogram

- body weight; ppm: parts per million (equivalent to milligrams per kilogram

- diet (mg/kg

- diet) for dietary exposure and milligrams per liter (mg/L) for aquatic exposures). Categories of acute toxicity for aquatic organisms (U.S. EPA, 2004) based on EC 50 or LC 50 (mg/L): < 0. 1 very highly toxic; 0.1

- 1 hi ghly 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). LC 50 (ppm): < 50 very highly toxic; 50

- 500 highly toxic; 501

– 1000 modera tely toxic; 1001

- 5000 slightly toxic; >5000 practically non

- toxic. LD 50 (mg/kg

- bw): < 10 very highly toxic; 10

- 50 highly toxic; 51

- 500 moderately toxic; 501

- 2000 slightly toxic; >2000 practically non

- toxic.

### Page 12 of 40 T ABLE 2 . Ecotoxicity Data Summary for EP ( BiobanTM CS

- 1135)

MRID No. Guideline Common

Name Taxonomic

Name Test Type %

a.i. Study

Duration Endpoint Toxicity Units Status Tox. Category

48559603 850.1400 Fathead

Minnow Pimephales promelas F EP 33 D NOEC ≥10 ppm Supplemental Upgradeable Pending AMP

Data Not applicable

48534004 850.1010 Water Flea Daphnia

magna S EP 48 hr EC 50 57 ppm Supplemental Upgradeable Pending AMP

Data Slightly

Toxic

48559602 850.1300 Water Flea Daphnia

magna S EP 21 D NOEC 5.0 ppm Supplemental Upgradeable Pending AMP

Data Not applicable

48534002 850.1075 Sheepshead

Minnow Cyprinodon variegatus SR EP 96 hr LC 50 > 100 mg/L Supplemental Upgradeable Pending AMP

Data Practically

Non

- Toxic

48534003 850.5400 Marine

Diatom Skeletonema

costatum S EP 96 hr IC 50 (yield) 4.0 mg/L Supplemental Upgradeable Pending AMP

Data Not appliable

Test Type

— O: oral; D: dietary; S: static; SR: static renewal; F: flow

- through. Unit

— mg/kg

- bw : milligrams per kilogram

- body weight; ppm: parts per million (equivalent to milligrams per kilogram

- diet (mg/kg

- diet) for dietary exposure and milligrams per liter (mg/L) for aquatic exposures)

. Categories of acute toxicity for aquatic organisms (U.S. EPA, 2004) based on EC 50 or 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). LC 50 (ppm): < 50 very highly toxic; 50

- 500 highly toxic; 501

– 1000 moderately toxic; 1001

- 5000 slightly toxic; >5000 practically non

- to xic. LD 50 (mg/kg

- bw): < 10 very highly toxic; 10

- 50 highly toxic; 51

- 500 moderately toxic; 501

- 2000 slightly toxic; >2000 practically non

- toxic.



### 5.2. **Toxicity to Freshwater**  **Aquatic Animals**

5 .2.1 Freshwater Fish

Acute toxicity tests for two species of fish using DMO were submitted and reviewed by

the Agency (MRIDs 00068770 and 00076969) : rainbow trout ( Oncorhynchus mykiss ) was used as the cold water species and bluegill sunfish ( Lepomis macrochirus ) was used as the warm water species; both of these species are preferred for acute toxicity testing. The studies are conducted under static conditions and no analytical measurements were made for the test substance. Given that the aquatic aerobic half

- l ife of DMO is less than one hour, the parent was not likely stable under test conditions. To maintain stable exposure concentrations given the expected half

- life, the tests should have been

conducted under flow

- through conditions and analytical measuremen ts made at a frequency and timing to document stability throughout the study duration. The se results provide only supplemental information about the toxicity of DMO and its degradates and are expected to underestimate the acute sensitivity of DMO to fish

. In regards to exposure to the hydrolysis degradate AMP and formaldehyde, the studies are still supplemental as no measurements of the concentrations of these and their stability throughout the duration of the study is documented. H owever, the se 96

- hour acute
studies still indicate that DMO and its resultant degradates can be expected to be at least slightly toxic to both cold and warm water fish

. These studies were originally classified

### Page 13 of 40 as acceptable , but the issues of DMO stability or stability of its degradates throughout the study duration were not noted or discussed. These studies were downgraded to supplemental because the studies do not document the stability, and fate information indicates that stability of DMO and AMP was not likely. These stud ies are expected to underestimate the acute sensitivity of DMO and AMP to fish.

The data requirements for DMO are not fulfilled; however since nontarget aquatic organisms ar e expected to be exposed to the degradation product (AMP) rather than the
parent f or the given registered uses , further DMO studies are not required at this time.

A fish

, early

- life stage study on the freshwater species, Fathead M innow ( Pimephales promelas ) under flow

- through conditions using EP BIOBANTM CS

- 1135 , was recently

submitted to the Agency and is supplemental, upgradable pending the A gency receive s a methodological explanation for BIOBANTM CS

- 1135 measurements (MRID 48559603) (see Table 2)

. BIOBANTM CS

- 1135 is known to be hydrolytically unstable and to rapidly degrade to AMP. Due to this known property of the test substance to rapidly degrade in water, the study author stated that the high treatment level was not analyzed for the parent

subst ance, however all data were reported in terms of BIOBANTM CS

- 1135. Further clarification of the methodology and AMP concentrations, if AMP was measured, is necessary before upgrading this study. Depending on the data received, this may satisfy

like guidel ine data requirements for the degradation product, AMP.

5 .2.2 Freshwater Invertebrates

The minimal testing required in order to establish the acute toxicity of AMP to freshwater invertebrates is a freshwater aquatic invertebrate toxicity test, preferably using first instar Daphnia magna or early instar amphipods, stoneflies, mayflies, or midges. A 48

- hour acute toxicity study (MRID 00076968) was conducted with the water flea ( Daphnia

magna ) using DMO ; however, this study provide s only supplemental informa tion as it

was conducted under static conditions but based on fate information DMO is not expected to be stable under study conditions

. This study was originally classified as acceptable , but the issues of stability were not noted or discussed. This stud y was downgraded to supplemental because the study does not document the stability (no analytical measurements were made for DMO or its degradates) , and fate information indicates that stability was not likely. Th is stud y is expected to underestimate the acute sensitivity of DMO and degradates to aquatic invertebrates. The acute endpoint result

from this supplemental study is listed in Table 1 and it is expected to underestimate the acute sensitivity of DMO and its degradates to freshwater invertebrates ; however, the study still indicate s that DMO and its degradates can be expected to be at least slightly

toxic to freshwater invertebrates. The data requirement for an acute freshwater

invertebrate are not fulfilled; however since nontarget aquatic organis ms ar e expected to be exposed to the degradation product (AMP) rather than the parent, further DMO studies are not required at this time.

An acute toxicity study and a chronic toxicity study with Daphnia magna using EP

BIOBANTM CS

- 1135 under flow

- through conditions , was recently submitted to the Agency and both are supplemental but upgradable pending the A gency receive s a

### Page 14 of 40 methodological explanation for BIOBANTM CS

- 1135 measurements (MRIDs 485 3 4004 and 48559603) (see Table 2)

. BIOBANTM CS

- 1135 is known to b e hydrolytically unstable and to rapidly degrade to AMP. Due to this known property of the test substance to rapidly degrade in water, the study author stated that the high treatment level was not analyzed for the parent substance, however all data were r eported in terms of

BIOBANTM CS

- 1135. Further clarification of the methodology and AMP concentrations, if AMP was measured, is necessary before upgrading th ese studies . Depending on the data received, this may satisfy like guideline data requirements for the degradation product, AMP.



### 5.3. **Toxicity to Estuarine and Marine Animals**

Acute toxicity d ata from studies using DMO with Pink S hrimp ( Penaeus duorarum)

, Eastern O yster ( Crassostrea virginica ), and Sheepshead M innows ( Cyprinodon variegatus) (MRIDs 76967, 102973, and 102974) were submitted to and reviewed by the Agency

. Although the estuarine/marine acute toxicity studies with Pink S hrimp and Sheepshead M innow were deemed acceptable in their initial review s by the EPA (MRID

76967 and 102974 )

, they have been downgraded to supplemental because t he studies are conducted under static conditions and no analytical measurements were made for the test

substance. Given that the hydroly s is half

- life of DMO is less than one hour, the parent

was not lik ely stable under test conditions but there were also no analytical measurements made on the degradates, so their concentrations and stability throughout the test are

unknown . The results of these supplemental studies are listed in Table 1 and the y are

exp ected to underestimate the acute sensitivity of DMO and its degradates to estuarine/marine organisms . The data requirements for DMO acute estuarine/marine organisms testing are not fulfilled; however since nontarget aquatic organisms ar e expected to be ex posed to the degradation product (AMP) rather than the parent, further studies are not required at this time. These aforementioned studies (Table 1 ) indicate that

DMO is at least practically non

- toxic to estuarine fish and shrimp species, while

mode rate to xicity was observed for Eastern O ysters exposed to this chemical.

A f ish acute toxicity test on the Sheepshead M innow ( Cyprionodon variegates ) using EP

BIOBANTM CS

- 1135 under flow

- through conditions , was recently submitted to the Agency and is supplemental, upgradable pending that the agency received a methodological explanation for BIOBANTM CS

- 1135 measurements ( MRID 48534002 ) (see Table 2)

. BIOBANTM CS

- 1135 is known to be hydrolytically unstable and to rapidly degrade to AMP. Due to this known property of the test substance to rapidly degrade in water, the study author stated that the high treatment level was not analyzed for the parent substance, however all data were reported in terms of BIOBANTM CS

- 1135. Further

clarification of the methodol ogy and AMP concentrations, if AMP was measured, is necessary before upgrading this study. Depending on the data received, this may satisfy guideline data requirements for the degradation product, AMP.

### Page 15 of 40 

### 5.4. **Toxicity to Aquatic Plants** 

No toxicity testing with an aquatic vascular or an emergent plant are available for DMO. Because of the rapid degradation of DMO into AMP and formaldehyde, no additional testing of DMO with aquatic plants is needed for the ecological risk assessment.

An alg al t oxicity test using the EP BIOBANTM CS

- 1135, was recently submitted to the Agency and is supplemental, upgradable pending that the A gency receive s a methodological explanation for BIOBANTM CS

- 1135 measurements at test initiation and termination ( MRID 4853 4003 ) (see Table 2). BIOBANTM CS

- 1135 is known to be hydrolytically unstable and to rapidly degrade to AMP. Due to this known property of the test substance to rapidly degrade in water, the study author stated that the high treatment level was not analyze d for the parent substance, however all data were reported

in terms of BIOBANTM CS

- 1135. Further clarification of the methodology and AMP concentrations, if AMP was measured, is necessary before upgrading this study. Depending on the data received, this m ay satisfy like guideline data requirements for the degradation product, AMP.



### 5.5. **Toxicity of Degradation Products** 

Exposure to nontarget organisms is more likely to be from its degradation products , AMP and formaldehyde, and not the parent compound DMO , which is expected to rapidly degrade (see fate summary) in aqueous environments. Toxicity information is needed to address discharge of these to the aquatic environment from discharge to WWTPs.

5.5 .1 AMP

An ecotoxicity summary report (DP Barcode # D208128) su ggests that AMP may be the true active ingredient of Bioban CS

- 1135 and the chemical of major concern in regard to any chronic effects to aquatic organisms. A summary of the ecotoxicity data for AMP is provided in Table 3, the data in this table were obta ined from a summary provided for OPPT’s HPV Challenge 8



### 5.5.1.1. Toxicity to Avian Species . W hile the data are posted as part of the HPV Challenge program the applicability of such data for use in this risk assessment is unknown without sufficient study details

. If this data is submitted, t he Agency will

review these studies for acceptability in meeting the data requirements

.

There is no acute or chronic toxicity data with an avian species with AMP. As birds can be exposed to AMP in their drinking water an acute o ral toxicity test with AMP using the species observed to be more sensitive to the parent DMO, the bobwhite quail is needed to evaluate acute risks to avian species.

No a vian reproduction study with AMP is required at this time; based on exposure to
AMP do es not meet any of the following criteria:

8 L etter dated 8/28/2011 from The Dow Chemical Company to Mark Townsend, Chief, HPV Chemicals Branch of

EPA/OCSPP/OPPT

### Page 16 of 40 **•** AMP is not stable in the environment to the extent that a potentially chronic toxic amount may persist in avian food;

**•** AMP is not expected to be stored or accumulated in plant or animal tissue, as indicated by its low octa nol/water partition coefficient

.

TABLE 3. Ecotoxicity Data Summary for AMP (HPV Database)

Common

Name Taxonomic Name Test Type Study

Duration Endpoint Toxicity Units Tox. Category

Bluegil l

Sunfish Lepomis

macrochirus S 96 hr LC 50 190 ppm Practically non

toxic

Ide Leuciscus idus S 48 hr LC 50 331 ppm Practically non

toxic

European

Plaice Pleuronectes platessa F 96 hr LC 50 184 ppm Practically non

toxic

Water Flea Daphnia magna S 48 hr EC 50 193 ppm Practically non

toxic

Brown Shrimp Cragnon cragnon F 96 hr EC 50 179 ppm Practically non

toxic

Test Type

— O: oral; D: dietary; S: static; F: flow

- through. Unit

— mg/kg

- bw : milligrams per kilogram

- body weight; ppm: parts per million (equivalent to milligrams per kilogram

- diet (mg/kg

- diet) for dietary exposure and milligrams per liter (mg/L) for aquatic exposures) Categories of acute toxicity for aquatic organisms (U.S. EPA, 2004) based on EC 50 or LC 50 (mg/L): < 0. 1 very highly toxic; 0.1

- 1 highly t oxic; >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). LC 50 (ppm): < 50 very highly toxic; 50

- 500 highly toxic; 501

– 1000 moderately tox ic; 1001

- 5000 slightly toxic; >5000 practically non

- toxic. LD 50 (mg/kg

- bw): < 10 very highly toxic; 10

- 50 highly toxic; 51

- 500 moderately toxic; 501

- 2000 slightly toxic; >2000 practically non

- toxic.



### 5.5.1.2. Toxicity to Freshwater Fish and Invertebrates

To esta blish the toxicity of the major degradation product

, AMP , to freshwater fish, one fish acute toxicity study using the most sensitive TGAI species is required. One such study has been submitted to the EPA via OPPT’s HPV Challenge. Although this study is considered acceptable for risk assessments conducted in the OPPT, under the TSCA, the study details would need to be submit ted to the OPP for the data to be used in the risk assessment for FIFRA registration review

. The data requirement is considered not

fulfilled until such data is submitted. Freshwater Fish, Acute and Chronic Toxicity

No chronic data are available for DMO’s major degradation product with freshwater fish. Because uses of DMO will result in repeated discharge of its major degradatio n product, AMP, to aquatic environments, a fish early life stage test with AMP is required. There should be an acute toxicity test available for the same species used in the chronic study.

### Page 17 of 40 To esta blish the toxicity of the major degradation product

, AMP , to freshwater

invertebrates , one invertebrate acute toxicity study using the Daphnia sp. is required. One such study exists in OPPT’s HPV Challenge program

. Although this study is considered acceptable f or risk assessments conducted in the OPPT, under the TSCA, the study details would need to be submit ted to the OPP for the data to be used in the risk assessment for FIFRA registration review. The data requirement is considered not

fulfilled until such da ta is submitted. Freshwater Invertebrate, Acute and Chronic Toxicity

No chronic data are available for DMO’s major degradation product with freshwater invertebrates. Because uses of DMO will result in repeated discharge of its major degradation product, AMP, to aquatic environments, an aquatic invertebrat e life

- cycle study test is required using the freshwater species, Daphnia magna

.

5.5.1.3. Toxicity to Estuarine/Marine Fish and Invertebrates

Acute toxicity testing with estuarine and marine organisms is required when an end

- use product is intended for direct application to the marine/estuarine environment or is expected to reach this environment in significant concentrations. The aquatic industrial use pattern of oil recovery for DMO may result in exposure to the estuarine

environment , and discharges from WWT Ps discharging to estuarine or marine waters for consumer product uses, water processing systems, etc . will result in exposure of aquatic organisms in this environment

.

Because the major degradation product, AMP, is expected to reach estuarine or marine

e nvironments, one estuarine/marine acute fish toxicity study, one acute crustacean toxicity study, and one mollusk study are required. An estuarine/marine acute fish toxicity study and an estuarine/marine acute crustacean toxicity study have been

submitted to the EPA via OPPT’s HPV Challenge Program

. Although these studies are considered acceptable for risk assessments conducted in the OPPT, under the TSCA, the study details would need to be submit ted to the OPP for the data to be used in the

risk assessmen t for FIFRA registration review. These data requirements are considered

not fulfilled until such data is submitted. Additionally, a mollusk embryo larvae study or shell deposition study is required with AMP

.

No chronic data are available for DMO’s maj or degradation product with

estuarine/marine invertebrates. A mysid life cycle study with AMP is required as chronic exposure has the potential to occur. With an acceptable mysid acute study the

chronic data would allow confirmation that the acute

- to

- chr onic ratio does not differ between saltwater and freshwater organisms, indicating that mode of action does not differ greatly between saltwater and freshwater species for the degradation product,

AMP.

### Page 18 of 40 5.5.1.4. Toxicity to Aquatic Plants
No algal toxicity data ha ve been submitted for the major degradation product, AMP. For the ecological risk assessment, including an endangered species assessment for all uses, the Agency anticipates needing algal toxicity data.

No toxicity testing with an aquatic vascular Lemna sp. has been submitted for its major degradation product, AMP

. One test with the major degradation product, AMP, is required.

No seedling emergence and growth test for i ts major degradation products are available. For uses where the antimicrobial is expected to reach aquatic environments, a seedling emergence and growth study with rice is required. Because of the rapid degradation of

DMO in the environment and the repea ted discharge and stability of AMP , the major degradation product, AMP, is required.

5.5 .2 Formaldehyde

Toxicity endpoints for formaldehyde from data submitted to OPP are presented below in

Table 4 . This data indicates the following:

**•** Formaldehyde (up to 37% ai) is slightly toxic to avian species on an acute oral basis and practically non

- toxic to avian species through subacute dietary exposure and is not expected to pose a significant hazard to avian species on an acute or subacute

bas is.

**•** Formaldehyde (up to 37% ai) is slightly to practically non

- toxic to freshwater fish on an acute basis and is not expected to pose a significant hazard to freshwater fish species

.

**•** Formaldehyde (up to 37% ai) is slightly toxic to freshwater invertebrat es as indicated by a supplemental study that does not fulfill guideline requirements (72

- 2a/OPPTS 850.1010) and must be repeated.

**•** The results of a core study in the silverside (148770), a n acceptable (or core ) study in the pink shrimp (148770), and a n acce ptable (or core ) study in the eastern oyster (148770) indicate that formaldehyde is slightly toxic to estuarine/marine fish and practically non

- toxic to moderately toxic to estuarine/marine invertebrates on an acute basis. Supplemental studies in inverteb rates indicate that formaldehyde is moderately toxic to shrimp, highly toxic to eastern oysters, and practically non

- toxic to fiddler

crabs.

TABLE 4. Ecotoxicity Data Summary for Formaldehyde

MRID

No Guideline Common

Name Taxonomic

Name Test Type % a.i. Study

Duration Endpoint Toxicity Units Status Tox. Category

148774 850.2100 Bobwhite Quail Colinus virginianus O 37% 21 D LD 50 790 mg/kg

bw A Slightly toxic

### Page 19 of 40 MRID

No Guideline Common

Name Taxonomic

Name Test Type % a.i. Study

Duration Endpoint Toxicity Units Status Tox. Category

148773 850.2200 Bobwhite Quai l Colinus virginianus D 37% 8 D LC 50 >5000 ppm A Practically non

toxic

148775 850.2200 Mallard

Duck Anas platyrhynchos D 37% 8 D LC 50 >5000 ppm A Practically non

toxic

132485 850.1075 Rainbow

Trout Oncorhynchus mykiss S 37% 96 hr LC 50 118 ppm A Practically non

toxic

101857 850.1075 Rainbow

Trout Oncorhynchus mykiss S 25.90% 96 hr LC 50 73.3 ppm S Slightly toxic

101857 850.1075 Rainbow

Trout Oncorhynchus mykiss S 32.37% 96 hr LC 50 2.24 ppm S Moderately toxic

101857 850.1075 Rainbow

Trout Oncorhynchus mykiss S 27.75% 96 hr LC 50 1.41 ppm S Moderately toxic

134124 850.1075 Rainbow

Trout Oncorhynchus mykiss S 18.80% 96 hr LC 50 >100 ppm S Practically non

toxic

132485 850.1075 Bluegill

Sunfish Lepomis

macrochirus S 37% 96 hr LC 50 100 ppm S Slightly toxic

101857 850.1075 Bluegill

Sunfish Lepomis
macrochirus S 25.90% 96 hr LC 50 41.4 ppm S Slightly toxic

101857 850.1075 Bluegill

Sunfish Lepomis
macrochirus S 32.37% 96 hr LC 50 1.79 ppm S Moderately toxic

101857 850.1075 Bluegill

Sunfish Lepomis

macrochirus S 27.75% 96 hr LC 50 1.51 ppm S Moderately toxic

134126 850.1075 Bluegill

Sunfish Lepomis

macrochirus S 37% 96 hr LC 50 68 ppm S Slightly toxic

134123 850.1075 Bluegill

Sunfish Lepomis

macrochirus S 8.80% 96 hr LC 50 >118 ppm S Practically non

toxic

132485 Atlantic

Salmon Salmo salar S 37% 96 hr LC 50 173 ppm S Practically non

toxic

132485 Lake Trout Salvelinus namaycush S 37% 96 hr LC 50 100 ppm S Slightly toxic

132485 Black

Bullhead Ameiurus

melas S 37% 96 hr LC 50 62.1 ppm S Slightly toxic

148772 850.1010 Water Flea Daphnia

magna S 37% 48 hr LC 50 14.31 ppm S Slightly toxic

148770 850.1075 Silverside Menidia

menidia S 37% 96 hr LC 50 69 ppm A Slightly toxic

148770 850.1035 Pink Shrimp Penaeus

duorarum S 37% 96 hr LC 50 143 ppm A Practically non

toxic

126396 850.1035 Pink Shrimp Panaeus

duorarum S 28% 96 hr LC 50 7.6 ppm S Moderately toxic

### Page 20 of 40 MRID

No Guideline Common

Name Taxonomic

Name Test Type % a.i. Study

Duration Endpoint Toxicity Units Status Tox. Category

128086 Pink Shrimp Panaeus

duorarum S 26% 96 hr LC 50 358 ppm S Practically non

toxic

126394 Pink Shrimp Panaeus

duorarum S 32% 96 hr LC 50 12 ppm S Slightly toxic

148770 Eastern Oyster Crassostrea virginica S 37% 48 hr EC 50 1.8 ppm S Moderately toxic

126396 Eastern Oyster Crassostrea virginica S 28% 48 hr EC 50 0.3 ppm S Highly toxic

128086 Eastern Oyster Crassostrea virginica S 26% 48 hr EC 50 2.9 ppm S Moderately toxic

126394 Eastern Oyster Crassostrea virginica S 32% 48 hr EC 50 0.47 ppm S Highly toxic

128086 Fiddler

Crab Uca pugilator S 26% 96 hr LC 50 >1000 ppm S Practically non

toxic

126396 Fiddler

Crab Uca pugilator S 28% 96 hr EC 50 380 ppm S Practically non

toxic

126394 Fiddler

Crab Uca pugilator S 32% 96 hr EC 50 290 ppm S Practically non

toxic

65640 Florida Pompano Trachinotus

carolinus S 37% 96 hr LC 50 69 ppm S Slightly toxic

Test Type

— O: oral; D: dietary; S: static; F: flow

- through. Units

— mg/kg

- bw : milligrams per kilogram

- body weight; ppm: parts per million (equivalent to milligrams per kilogram

- diet (mg/kg

- diet) for dietary exposure and milligrams per lite r (mg/L) for aquatic exposures). Status

— S: Supplemental; A: Acceptable. Categories of acute toxicity for aquatic organisms (U.S. EPA, 2004) based on EC 50 or LC 50 (mg/L): < 0. 1 very highly to xic; 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). LC 50 (ppm): < 50 very highly toxic; 50

- 500 highly toxic; 501

– 1000 moderately toxic; 1001

- 5000 slightly toxic; >5000 practically non

- toxic. LD 50 (mg/kg

- bw): < 10 very highly toxic; 10

- 50 highly toxic; 51

- 500 moderately toxic; 501

- 2000 slightly toxic; >2000 practically non

- toxic.



## 6. Facility Emissions to WWTP Modeling

For assessing the fate of DMO and its major degradates or reaction products emitted to receiving waters from industrial process water uses of DMO such as metal working fluids, oilfield water systems, oilfield drilling muds and workover and comple tion fluids, and consumer house hold and industrial products, the Agency anticipates using the available environmental fate information from guideline studies for DMO and its major degradates and the following

emissions scenarios:

**•** Potential environmental r eleases and associated exposures of concern for antimicrobial uses related to consumer products including dishwashing and laundry liquids, surface cleaners and polishes, will be those identified in the down the drain

module of EFAST for consumer products

.

### Page 21 of 40 **•** Potential environmental releases and associated exposures of concern for antimicrobial uses related to the metalworking industry will be those identified in “Emissions Scenario Document on the Use of Metalworking Fluids”, Number 28 of

OECD Series on Emissi on Scenario Documents dated July 6, 2011

.

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

antimicrobial uses related to the Oil Well Treatment Industry ( oilfield water systems )

will be those identified in the “New Chemical Scenario for Well Treatment Chemicals” within the latest version of Generic Scenarios developed by the Chemical Engineering Branch of the US EPA Office of Polluti on Prevention and Toxics (OPPT)

.

**•** Potential environmental releases 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 Productio n Industry or the “New Chemical Scenario for Drilling Muds” within the latest version of Generic Scenarios developed by the Chemical Engineering

Branch of the OPPT. In the latter , it is assumed that all of the production volume is disposed of by landfill unless the submitter states that the product is to be used in

water

- based muds for offshore drilling, in which case it is assumed that intermittent ocean discharges occur at 5,000 kg/site.

Facility information is needed to estimate aquatic exposures from emissions to wastewater treatment plants (WWTP) for each emissions scenario and directly to water from the oil and gas well development sites. The agency will make stringent assumptions in the absence of the following data:

**•** The portion of the production volume of DMO used in consumer household and industrial laundry and cleaning products ;

**•** The number of metalworking sites using DMO or the maximum annual production volume of DMO used in metalworking facilities in the United States and its territories;

**•** The number of oil and gas well development sites using DMO or the maximum annual production volume of DMO in oil and gas well development in the United States and its territories;

**•** How many of each of these facilities (metalworking, oi l and gas well development)

have on

- site and/or off

- site wastewater treatment.

In the absence of information on the number of these facilities that use DMO 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 States have the potential to use DMO.

In the absence of appropriate test data on biodegradation during wastewater treatment, the Agency will assume that there is no removal of AMP during wastewater treatment and that the

amount of AMP 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 AMP during drinking water treatment the Agency will a ssume there is no removal of

AMP

.

### Page 22 of 40 

## 7. Environmental Fate and Ecotoxicity Data Gaps and Anticipated
Work

DMO degrades rapidly by hydrolysis in minutes to form AMP ( CAS No. 124

- 68

- 5), which is stable to abiotic degradation processes. Because DMO is hydrolyzed so rapidly to AMP, photodegradation of DMO in water is not a significant route of degradation. The Agency's

in

- house database does not have any acceptable environmental fate and transport data on the degradate, AMP. These data are required t o assess environmental fate for the registered use patterns that may potentially enter waste water treatment plants (WWTPs) and subsequently be discharged to aquatic environments.

An examination of the chemical structure and a review of information in a R obust Summary for AMP indicate that a high percentage (~89%) of AMP may be removed by conventional sewage treatment systems. The primary removal mechanism was attributed to

mineralization.

To be able to give merit to this claim, the Agency would need t o review and evaluate the primary references cited in this letter to the Agency. Without reviewing and evaluating these primary references and reaching the same conclusions as those presented, the Agency anticipates needing

environmental fate data from tes ts including the activated sludge respiration inhibition (ASRI) test and depending on the outcome of the ASRI test, either a ready biodegradability test or one of the following simulation tests: porous pot test, or simulation tests to assess the biodegr adability of chemicals discharged in wastewater, or simulation test

- aerobic sewage treatment: A. Activated Sludge Units.

**•** The Agency anticipates needing the following environmental fate data (guideline line number (GLN)) in order to conduct a complete environmental fate assessment :

o Activated Sludge Sorption Isotherm (GLN 835.1110);

o Anaerobic aquatic metabolism for the degradate AMP ( GLN 835.4400 ) ;

o Aerobic aquatic metabolism for the degradate AMP ( GLN 835.4300 ) ;

o Ready biodegradability ( GLN 835.3110)

, or Porous Pot Test (GLN 835.3220) , or Simulation Tests to Assess the Biodegradability of Chemicals Discharged to

Wastewater (GLN 835.3280) , or Simulation Test

– Aerobic Sewage Treatment: A. Activated Sludge Units (GLN 835.3240) for AMP 9



### .

9 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 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) Biodeg radation in Activated Sludge 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 Acti vated Sludge or the Porous Pot study is required.

### Page 23 of 40 The Agency is aware that data on the fate of DMO and its degradates on sewage treatment have

been submitted to the OPPT

. If the registrant has access to these studies, they can be submitted to OPP for review to meet the data requirements.

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

Waste Water Microbes

o Activated Sludge Respiration Inhibition for AMP ( GLN 850.6 800 or OECD 209 ) ;

Avian Species

o Avian acute oral toxicity test, using the bobwhite quail for AMP (OCSPP 850.2100) ;

Freshwater Fish Species

o Freshwater fish acute toxicity, most a.i. sensitive species the bluegill sunfish

— major degradation product, AMP (OCSPP 850.1075);

o Fish early

- life stage toxicity test, freshwater species with the same species acute toxicity is conducted on (bluegill sunfish)

— major degradation product, AMP (OCSPP 850.1400) ;

Freshwater Invertebrate Species

o Freshwater invertebrate acute toxicity, Daphnia magna

— major degradation product, AMP (OCSPP 850.1010) ;

o Aquatic invertebrate life

- cycle, freshwater Daphnia magna

— major degradation product, AMP (OCSPP 850.13 0 0) ;

Estuarine/Marine Animal Species

o Estuarine/marine fish acute toxicity study

— major de gradation product, AMP (OCSPP 850.1075);

o Estuarine/marine invertebrate acute toxicity using the saltwater mysid

— major degradation product, AMP (OCSPP 850.1035);

o Mollusk e mbyro larvae or shell deposition study

— major degradation product, AMP (OCSPP 850.105 5 or 850. 1025 );

o Aquatic invertebrate life

- cycle, saltwater Americamysis bahia

— major degradation product, AMP (OCSPP 850.13 5 0) ;

Aquatic Plant Species

o Seedling emergence (Tier II) with rice

— major degradation product, AMP (OCSPP 850.4225);

o Aquatic plant toxicity test using Lemna spp.

— major degradation product, AMP (OCSPP 850.4400);

o Algal toxicity (Tier II) for four s pecies

— major degradation product, AMP (OCSPP 850.5400).

### Page 24 of 40 The Agency is aware that data on the ecotoxicity of DMO’s degradation product, AMP, have been submitted to OPPTS

. While the data is posted as part of the HPV Challenge program the applicability of such data for use in this risk assessment is

unknown witho ut sufficient study detail s. Such details can not be provided to OPP without consent of the owner’s of the data. If the registrant has access to these studies, they can be submitted to OPP for review to meet data requirements.

### Page 25 of 40 Appendix A Summary of Reg istration Information

Table 1. Registered Products of 4,4

- Dimethyloxazolidine

EPA Registra

tion# Registration

Name Company

Name Formulation Type % of

Active Ingredient Use Patterns

464

- 660 Bioban CS

- 1135

Antimicrobial Agent The Dow Chemical

Co. Ready

- to

- U se Solution 78 Material Preservative

and Industrial Process and water systems: oilfield water systems

464

- 664 Bioban CS

- 40l

Preservative The Dow Chemical

Co. Ready

- to

- Use

Solution 38 Industrial Process and
water systems: oilfield water systems

1529

- 32 Nuosept 101

Preservative International Specialty Products Ready

- to

- Use

Solution 77 Material Preservative

1529

- 37 Nuosept 166

Preservative International Specialty Products Soluble Concentrate 65.63 Material Preservative

5383

- 82 Troysan 192 II Troy Chemical Corp Ready

- to

- Use

Solution 73.7 Material Preservative

and Industrial Process and water systems: oilfield water systems

5383

- 90 Troysan 186

Formula II Troy Chemical Corp Soluble Concentrate 68 Material Preservative



### Table 2. Registered Use Sites

Site Name

Materials Preservatives

Adhesives (non

- food contact)

Adhesives (Joint Cements)

Adhesives (Nonfood Contact Preservative Incorporation)

Antimicrobial

Caulking Compounds

Cleansers

Dispersed Colors

Drilling Muds, and Workover & Completion Fluids

Die

- Cast Lubricants and Mold

- Release Agents

Fabric Softeners

Floor Wax Emulsions

Grouts

Household and Institutional Products, Dishwashing Liquids

Hydraulic Fluids

Industrial Preservat ive (In

- can Preservative)

Inks

Liquid Detergents

Liquid Products (Unspecified)

Metalworking Cutting Fluids

### Page 26 of 40 Metal Working Fluids

Mineral Slurries

Paints

Paints (Latex)

Pigment Slurries

Polishes

Resin Emulsions

Sealants

Spackling

Surfactants (Anionic, Nonionic Amphoteric and Cationic Surfactants)

Wallboard Joint Compound

Industrial processes and water systems

Oilfield Water Systems

Subsurface Injection Water

Secondary Oil Recovery Injection Water

Oilfield and Gas Water Injection Systems

Oil Recovery Drilling Mud

Oil Recovery Packer Fluid



### Table 3. Target Pests

Pest Name

Deterioration/Spoilage Bacteria

Aerobic slime

- forming bacteria, Pseudomonas sp.

Slime

- Forming Bacteria

Anaerobic Sulfate

- Reducing Bacteria

, Desulfovibrio desulfuricans

Iron

- oxidizing bacteria, Gallionella sp.

Antimicrobial

### Page 27 of 40 Appendix B . Environmental Fate Guideline Study Justifications Study Title: Activated Sludge Sorption Isotherm

Guideline Number: 835.1110

Test Substance: AMP

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). No data is currently available. 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 non

- target organisms. EPA nee ds activated sludge sorption study data to assess the distribution of the antimicrobial chemical among the solid, aqueous, and vapor phases of WWTPs. Specifically, this study identifies those chemicals which sorb to sludge

biomass. Practical Utility of t he 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 wa stewater 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 di rect 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 partitio ns 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 furt her 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 organisms 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 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 derived 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” requi rements 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 endangered or threate ned 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 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 consi der 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 28 of 40 Study Ti tle: Aerobic Aquatic Metabolism

Guideline Number: 835.4300

Test Substance: AMP Rationale for Requiring the Data Aerobic aquatic metabolism data is needed to conduct the environmental fate assessment to support the

DMO uses in consumer household and industrial cleaning products, material preservative and industrial

slimicide uses . Acceptable data on the aerobic aquatic metabolism of AMP in two

- sediment systems are required. The data is not currently available. The Agency has limited understanding of how AMP behaves in aerobic aquatic environments after discharge to receiving wat er. The purpose of aerobic aquatic metabolism study 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 degradates. This information will determine the persistence and concentrations of AMP over time in representative aerobic water/sediment systems. The results of the study will indicate the potential for AMP to co ntaminate 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. Data are needed for two sediment

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

Practical Utility of the Data

1. How will the data be used? The data would establish the significance of aerobic aquatic microbial degradation of AMP 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 the aerobic aquatic aerobic half

- l ife of AMP 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 format ion and decline under aerobic aquatic conditions of AMP and it’s degradates that may be taken up by sediment biota and passed on to other parts of the aquatic food web, and facilitates assessment of potential disposal problems. The study helps to determine the degradation rate (half

- life) of AMP in the presen ce of microorganisms in different natural water/sediment systems and establishes what metabolites (degradates) are formed under aerobic (oxygen

- rich) conditions in the laboratory. If no acceptable aerobic aquatic metabolism data is available for AMP, it w ould be assumed to be stable to aerobic metabolism and we would not know if the chemical breaks down 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 heal th or the environment.

### Page 29 of 40 Study Ti tle: Anaerobic Aquatic Metabolism

Guideline Number: 835.4400

Test Substance: AMP Rationale for Requiring the Data Anaerobic aquatic metabolism data is needed to conduct the environmental fate assessment is needed to conduct the environmental fate assessment to support the DMO uses in consumer household and industrial cleaning products, material preservative and indust rial slimicide uses . Acceptable data on the anaerobic aquatic metabolism of AMP in two

- sediment systems are required. The data is not currently available. The Agency has limited understanding of how AMP behaves in anaerobic aquatic environments after di scharge 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 during 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 AMP and potential degradates over time in representative anaerobic water/sediment systems. The results of the study will indicate the potential for AMP 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 prev ail 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. Practical 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 AMP residues in

water and sediment. The data would establish the significance of an aerobic aquatic microbial degradation

of AMP 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 the an aerobic aqua tic microbial half

- life of AMP in water/sedim ent 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 ana erobic aquatic conditions of AMP 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 disposal problems. The study helps to determine the degradation rate (half

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

- poor) conditions in the laboratory

. If the data indicate that degradatio n 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 AMP residues of concern do not persist in these
systems. If data indicate th at 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

AMP residues of concern persist in aquatic systems under anaerobic conditions. In the absence of the requested data, AMP anaerobic aquatic metabolism half

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

.

### Page 30 of 40 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; 835.3220; 835.3240; or 835.3280 , r espectively

Test Substance: AMP 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 antimicrobial is broken down by bacteria. These study results supply information on the rate of biological br eakdown 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 four biodegradation tests are required. If the ASRI test EC 50 is less than or equal to 20 mg/L, then either the (i) Biodegradation in Activate d 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 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 antimicrobial passes the Ready Biodegradability study, then no further testing is required. If, however, the antimicrobial fails the Ready Biodegradability study, then the (i) Biodegradation in Activated Sludge or (ii) Simulation Test

– Aerobic Sewage Treatmen t: A. Activated Sludge Units, or (iii) 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 co ncentrations of antimicrobial pesticide 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 t he 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 chemica l 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 determination 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 rea dily biodegraded, then activated sludge 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 aqu atic organisms to determine concentrations 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 respirat ion inhibition test, then higher

- tiered 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, the

### Page 31 of 40 risk assessments 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 f or 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 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 or adverse modification of critical habitat” and to use the best scientific data available” in carrying out this obligation. The data EPA intends t o 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 pestici de 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 an d registrants have in coming into compliance with the ESA and could result in use restrictions which are unnecessarily severe.

### Page 32 of 40 Appendix C : Ecological Guideline Study Justifications Study Title: Aquatic Invertebrate Acute Toxicity Test, Freshwater Species

Guideline Number: 850.10 10

Test Substance: Degradation Product: AMP Rationale for Requiring the Data

No data are available to assess the potential acute lethal risks of the major toxic degradation product, AMP, to freshwater invertebrates. Aquatic invertebrate data for AMP are necessary because freshwater

invertebrates may be exposed based on DMO ’s use pattern s, fate, and monitoring data

. DMO is used in metal working fluids, oilfield water systems, oilfield drilli ng muds and workover and completion fluids,

and consumer, household and industrial products which can result in discharge of DMO and its major degradate, AMP to surface waters. The requested data would allow EPA to estimate risks to freshwater

invertebrat es from exposure to AMP , including defining an action area for endangered species

. Practical Utility of the Data

1. How will the data be used? These data are needed for a registration review decision and for an endangered species assessment, which will be conducted as part of that decision. The freshwater invertebrate acute study data would allow the Agency to analyze acute lethal effects to fre shwater invertebrates from acute exposures due to DMO’s use patterns and fate. The effects data with the degradate would be used to de termine the likelihood that the

acute risks can potentially impact aquatic communities, either by direct effects on inver tebrates 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? Risk estimates (i.e., risk quotients or concentration of concern values) cannot be evaluated without these data. In the absence of data, if an acute toxicity test is available for DMO

, the toxicity of the degradate

will be assumed to be e quivalent to that of the parent, DMO. O therwise

, acute risks to freshwater invertebrates would be presumed; the Agency would have to assume that DMO and its degradate “may affect” endangered freshwater invertebrates directly (and endangered species from other taxa indirectly)

. T he lack of these data wi ll 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 withdrawal of uses for DMO which may otherw ise be avoided, or which are unnecessarily severe.

Study Title: Estuarine/marine invertebrate acute toxicity test one crustacean species

Guideline Number: 850.10 3 5

Test Substance: Degradation Product AMP Rationale for Requiring the Data

A crustacean (mysid) is one of two representative saltwater species used to evaluate acute effects for all estuarine/marine invertebrates. No acceptable acute study for AMP with an estuarine/marine crustacean species has been submitted. No acceptable acute studies f or the major degradate, AMP, with an estuarine/marine crustacean species. An acute test using a crustacean is required because th is major degradate is expected to reach estuarine/marine environmen t s based on DMO use pattern s, and fate data.

In the absenc e of data, the degradate would be assumed to be as toxic as the supplemental study results with DMO. However, this will introduce a large degree of uncertainty into the assessment as the concentration of DMO, AMP, and other degradates is unknown in the st udy and could potentially result in an underestimation of risk from continuous exposure from discharges from WWTPs. Practical Utility of the Data

1. How will the da ta be used? These data are needed for a registration review decision and for an endangered species assessment, which will be conducted as part of that decision. The estuarine /marine invertebrate acute studies allow the

### Page 33 of 40 Agency to analyze acute lethal effects to estuar ine/marine invertebrates from acute exposures due to BTS

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 acute mysid data, acute risks to marine/estuarine invertebrate s would be calculated

based on supplemental DMO data alone

. But there would be uncertainty in whether the calculated risk is an underestimate, and the degree of underestimation is unknown . Decisions may be made incorrectly

based on these results.

Study Title: Estuarine/Marine Mollusk Study

— Either a Shell Deposition or an Embryo \ Larvae Study

Guideline Number: 850.10 2 5 or 850. 1055 , respectively

Test Substance: Degradation Product AMP Rationale for Requiring the Data

A mollusk is a representative saltwater species used to evaluate acute effects for all estuarine/marine invertebrates. No acceptable acute studies for the major degradate, AMP, with an estuarine/marine

mollusk has been submitted. An acute test using an estuarine/marin e mollusk species is required because

th is major degradate is expected to reach estuarine/marine environmen t s based on DMO use pattern s, and

fate data. A mollusk study is also required because it tentatively appears likely to be the most sensitive of

all aquatic organisms, both freshwater and estuarine/marine based on the acceptable DMO mollusk study and the supplemental freshwater fish and invertebrate data. The mode

- of

- action to mollusks may be different from that of crustaceans and fish, and therefore any DMO: AMP ratio or factor derived from crustacean or fish data may underestimate the degradate toxicity to mollusks. In the absence of data, the degradate AMP would be assumed to be as toxic as the parent, DMO, for the mollusk. Practical Utility of the Data

1. How will the da ta be used? These data are needed for a registration review decision and for an endangered species assessment, which will be conducted as part of that decision. The estuarine /marine invertebrate acute studies allow the Agency to analyze acute lethal effects to estuarine/marine invertebrates from acute exposures due to

DMO 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 acute mollusk data, acute ris ks to marine/estuarine mollusks would be calculated assuming that the degradate is as toxic as the parent, and potentially be based on the DMO mollusk data which may result in underestimation of risk

.

Study Ti tle: Fish Acute Toxicity Test, Freshwater Species, Most Sensitive of the DMO S pecies

— Bluegill Sunfish

Guideline Number: 850.1075

Test Substance: D egradation Product: AMP Rationale for Requiring the Data No data are available to assess the potential acute lethal risks of the major toxic degradation product,

AMP

, to freshwater fish. Fish acute data for AMP are necessary because freshwater fish may be exposed

based on DMO ’s use pattern, fate, and monitoring data. Only data for the most sensitive of the TGAI

### Page 34 of 40 species is required, as this should also be the most sensitive species for the degradate. DMO is used in metal working fluids, oilfield water systems, oilfield drilli ng muds and workover and completion fluids, and consumer, household and industrial products which can result in discharge of DMO and its major degradate, AMP

, to surface waters. The requested data would allow EPA to estimate risks to freshwater

fish from exposure to AMP , including defining an action area for endangered species. Practical Utility of the Data

1. How will the da ta be used? These data are needed for a registration review decision and for an endangered species assessment, which will be conducted as part of that decision. The freshwater fish acute study data would allow the Agency

to analyze acute lethal effects to freshwater fish from acute exposures due to DMO use and fate. The

effects data with the degradate 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? Risk estimates (i.e., risk quotients or concentration of concern values) cannot be evalua ted without these

data. In the absence of data, if an acute toxicity test is available for DMO the toxicity of the degradate will be assumed to be equivalent to that of the parent DMO otherwise if no TGAI or degradate data are

available acute risks to fre shwater fish would be presumed; the Agency would have to assume that DMO and its degradate “may affect” endangered freshwater fish directly (and endangered species from other taxa indirectly)

. 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 withdrawal of uses for DMO which may otherwise be avoided, or which are unnecessarily severe.

Study Title: Fish Acute Toxicity Test, Estuarine/Marine Species

Guideline Number: 850.1075

Test Substance: Degradation Product: AMP Rationale for Requiring the Data No data are available to assess the potential acute lethal risks of the major toxic degradation product,

AMP

, to estuarine/marine fish . Fish acute data for AMP are necessary because estuarine/marine fish may be exposed based on DMO’s use pattern, and fate data. DMO is used in metal working fluids, oilfield water systems, oilfield drilling muds and workover and completion fluids, and consumer, household and industrial products which can result in discharge of DMO’s major degradate, AMP, to surface waters. The requested data would allow EPA to estimate risks to estuarine/marine fish from exposure to AMP, including defining an action area for endangered species. Practical Utility of the Data

1. How will the da ta be used? These data are needed for a registration review decision and for an endangered species assessment, which will be conducted as part of that decision. The estuarine/marine acute study data would allow the Agency

to analyze acute lethal effects to estuarine/ marine fish from acute exposures due to DMO use and fate.

The effects data with the degradate 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? Risk estimates (i.e., risk quotients or concentration of concern values) cannot be evalua ted without these

data. In the absence of data, if an acute toxicity test is available for DMO the toxicity of the degradate will be assumed to be equivalent to that of the parent DMO otherwise if no TGAI or degradate data are

### Page 35 of 40 available acute risks to est uarine/marine fish would be presumed; the Agency would have to assume that

DMO and its degradate “may affect” endangered estuarine/marine fish directly (and endangered species from other taxa indirectly)

. 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 withdrawal of uses for DMO which may otherwise be avoided, or which are unnecessarily severe.

Study Title : Aquatic Inv ertebrate Life

- Cycle, Freshwater Species

Guideline Number: 850.13 0 0

Test Substance: Degradation Product: AMP Rationale for Requiring the Data

No chronic life cycle toxicity data for a freshwater invertebrate species ha s been submitted for the major degradate, AMP. Chronic aquatic invertebrate data for this degradate are necessary because based on

DMO ’s use pattern s, fate, and monitoring data freshwater invertebrates may be repeatedly exposed to DMO and its major degradate, AMP

. DMO is used in metal working fluids, oilfield water systems, oilfield drilling muds and workover and completion fluids, and consumer, household and industrial products which can result in discharge of DMO and its major de gradate, AMP to surface waters. The requested data would allow the Agency to estimate chronic risks to freshwater invertebrates from exposure to this degradate, including defining an action area for endangered species. Without these data, the Agency woul d have to assume that the degradate is at least as toxic as the parent, DMO

. However, there is no chronic data for the parent either, so w ithout these data, the Agency is unable to evaluate the potential risks to freshwater

invertebrates associated with c hronic exposure to DMO or its degradate. 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. Practical Utility of the Data

1. How will the data be used? These data are needed for a registration review decision and for an endangered species assessment, which will be conducted as part of that decision. The aquatic invertebrate life

- cycle study would allow the Agency to analyze chronic effects, including eff ects on reproductive success , survival and growth, to

freshwater invertebrates due to exposure to the degradate, AMP . 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 on fish by reducing their food sources.

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

- making? In the absence of data, the Agency would have to assume that the degradate is at least as toxic as the parent,

DMO

. However, there is no chronic data for the parent either, so w ithout these data, the Agency is unable to evaluate the potential risks to freshwater invertebrates associated with chronic exposure to DMO or its degradate. 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 withdrawal of uses for DMO which may otherwise be avoided, or which are unnecessarily severe.

Study Title : Aquatic Invertebrate Life

- Cycle, Estuarine/Marine Species

Guideline Number: 850.13 5 0

Test Substance: Degradation Product: AMP Rationale for Requiring the Data No chronic life cycle toxicity test for an estuarine/marine invertebrate species has been submitted for the degradate, AMP. Chronic aquatic invertebrate data for this degradate is necessary because based on

### Page 36 of 40 DMO’s use pattern, and fate data estuarine/marine invertebrates may be repeatedly exposed to DMO’s major degradate, AMP. DMO is used in metal work ing fluids, oilfield water systems, oilfield drilling muds and workover and completion fluids, and consumer, household and industrial products which can result in discharge of DMO and its major degradate, AMP to surface waters. Without the estuarine/marin e life

cycle data for the degradate, the Agency is unable to evaluate the potential chronic risks to estuarine/marine invertebrates associated with chronic exposure to the degradate. T he Agency would have to presume

chronic risk to listed and non

- listed e stuarine/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 effects, 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, e ither 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 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 compliance with the Endangered Spec ies Act, and could result in use restrictions or withdrawal of uses for DMO which may otherwise be avoided, or which are unnecessarily severe.

Study Title: Fish E arly

- life Stage Toxicity Test, Freshwater Specie s using Bluegill Sunfish the more

sensitiv e of the acute tests with DMO

Guideline Number: 850.1400

Test Substance: Degradation Product: AMP Rationale for Requiring the Data No fish early

- life stage toxicity test for the major degradate, AMP, has been submitted. The fish early

- life
stage toxicity test provides the lethal and sublethal effects of a test substance on fish species. Chronic aquatic invertebrate data for this degradate are necessary because based on DMO’s use pattern, fate, and monitoring data, freshwater invertebrates may be repeatedly exposed to DMO and its major degradate, AMP. DMO is used in metal working fluids, oilfield water systems, oilfield drilling muds and workover and completion fluids, and consumer, household and industrial products which can result in discharge o f DMO and its major degradate, AMP to surface waters. The requested data would allow the Agency to estimate chronic risks to freshwater fish from exposure to this degradate, including defining an action area for endangered species. Without these data, th e 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 the degradate. If the test is not conducted 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 acutely sensitive species.

### Page 37 of 40 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 DMO and its degradate. The data will reduce

uncerta inties 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 future decision

- making? In the absence of data, the toxicity of the degradate would be assumed to be the same as that of the parent, if chronic data for the parent was submitted, or if these data are not available either chronic risks would be presumed to freshwater fish/amphibia ns 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 compliance with the Endangered Species Act, and could result in use restrictions or withdrawal of uses for DMO which may otherwise be avoided, or which are unnecessarily severe.

Study Title: Seedling emergence Tier II Test Species: Rice, 

### Oryza sativa

Guideline Number: 850.4225

Test Substance: Degradation Product: AMP 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 seedling emergence and growth toxicity data for a rooted emergent vascular plant ha s been submitted

for DMO or its major degradate. Based on the fate of DMO , it is not expected to be persistent in the water column or sediment. However, the major degradate is more persistent and may sorb onto organ ic and inorganic particles in water and deposit them in sedimentary areas such as lakes, and freshwater and

saltwater marshes. U se s of DMO in metal working fluids, oilfield water systems, oilfield drilling muds and workover and completion fluids, and consumer, household and industrial products are expected to lead to exposure of wetland plants due to transportation, and deposition of AMP sorbed onto particles in

the waste stream from use sites. Without this data, the Agency is unable to evaluate the p otential risks to rooted vascular emergent plants associated with exposure to AMP

. In the study, a minimum of four replicates are necessary to allow a nonparametric statistical analysis, if the resulting data fail normality or homogeneity of variance assu mptions. Practical Utility of the Data

1. How will the data be used? These data are needed for a registration review decision and for an endangered species assessment, which will be conducted as part of that decision. Emergent 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 t he Agency to analyze to a critical component of the structure and function of an aquatic
ecosystem. A toxicity study on an emergent vascular plant species is used to establish a dose response relationship of DMO 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 throu gh impacts such as loss of a food resource, habitat, or habitat quality

.

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

- making? In the absence of data, r isks to emergent aquatic plants could not be calculated

. Therefore, until

additional dat a become available, risks to emergent vascular plants (both Federally

- listed and non

- listed

### Page 38 of 40 species) will be assumed in future DMO 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 withdrawal of uses

for DMO which may otherwise be avoided, or which are unnecessarily severe.

Stud y Title: Aquatic Plant Growth, F loating V ascular S pecies ( Lemna sp. ), Tier II

Guideline Number: 850.4 400

Test Substance: Degradation Product: AMP Rationale for Requiring the Data

No non

- rooted vascular aquatic plant toxicity data ha s been submitted for the major degradate AMP

. DMO is used in metal working fluids, oilfield water systems, oilfield drilling muds and workover and completion fluids, and consumer, household and industrial products which can result in discharge of

DMO and its major degrad ate, 

### AMP to surface waters

. The requested data would allow the Agency to
estimate risks to aquatic plants from exposure to AMP , including defining an action area for endangered species

. Practical Utility of the Data

1. How will the data be used? These data are needed for a registration review decision and for an endangered species assessment, which will be conducted as part of that decision. Mats of floating non

- rooted aquatic plants provide habitat for small invertebrates, food and shelter for f ish and amphibians, and food for waterfowl and marsh birds. The floating vascular aquatic plant study would allow the Agency to evaluate effects to a critical component of the structure and function of the aquatic plant community. A toxicity study on a n on

- rooted vascular aquatic plant species is used to establish a dose response relationship of AMP 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 li kelihood that losses to non

- rooted aquatic vascular plants 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 t he Agency's future decision

- making? In the absence of data, the toxicity of the degradate would be assumed to be the same as that of the parent, if data for the parent was submitted, or if this data are not available either risks would be presumed for listed and nonlisted aquatic plants

. 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 withdrawal of uses for DMO which may otherwise be avoided, or which are unnecessarily severe.

Study Title: Algal Toxicity

, 4 species , Tier II

Guideline Number: 850.5400

Test Substance : Degradation Product: AMP

Rationale for Requiring the Data

No nonvascular aquatic plant toxicity data ha s been submitted for the major degradate AMP . U se s of

DMO in metal working fluids, oilfield water systems, oilfield drilling muds and workover and completion fluids, and consumer, household and industrial products are expected to lead to exposure of aquatic organisms due to the repeated release and transport of DMO’s major degradate , AMP, from use sites into aquatic ecosystems. Without th is degradate data, t he Agenc y would have to presume ri sk to federally

listed and non

- listed non

- vascular plants

, but would not be able to quantify the risk.

### Page 39 of 40 Practical Utility of the Data

1. How will the data be used? These data are needed for a registration review decision and for an endangered species assessment, which will be conducted as part of that decision. The aquatic nonvascular plant study would allow the Agency to analyze effects on primary production from exposure to the degradate. A toxicity study on non

vascular aquatic plant species is used to establish a dose response relationship of the degradate with primary productivity in terms of yield, growth rate, and area under the g rowth curve . The effects data

would be used to determine the likelihood 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 future decision

- making? In the absence of data, the toxicity of the degradate would be assumed to be the same as that of the parent, if data for the parent was submitted, or if this data are no t available then risks would be presumed to listed and nonlisted aquatic plants

. Therefore, until additional data become available, risks to aquatic non

vascular plants (both Federally

- listed and non

- listed species) will be assumed in future DMO 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 o r withdrawal of uses for DMO which may otherwise be avoided, or which are unnecessarily severe.



### Guideline Number: 850. 2100 Study Title: A cute avian oral toxicity

Test Substance: Degradation Product: AMP 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 AMP . This study would allow the Agency to categorize AMP as toxic or non

- toxic to birds. If the avian acute oral LD 50 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 AMP 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 study is required to establish the toxicity of a pesticide to birds.

### Page 40 of 40 Guideline Number: 850.6800; OECD 209 Study Title: 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 det ermine 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 biod egradability test, if that 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 to 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) Biodeg radation in Activated Sludge 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 Acti vated 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 c oncentration 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 coul d 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. Al so, 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 adv ersely impacted.