### 2 of 2 2 Bronopol products are currently registered for use in aquatic and terrestrial oil and gas production areas to control bacteria and fungi in flood waters, f r actur ing fluids, oil process water

, oil and gas pipeline s, and tank maintenance. It is also used in industrial recirculating water cooling tower and evaporative condensers, paper mill process w a ter, air scrubber units, and as a materi al preservative in such pr oducts as adhesives, metalworking cutting fluids, absorbent clays, starch, pigment, mineral slurries, paints and emulsions systems, paper (bulk pulp), water base d printing inks and fount solutions.

Science Findings

The Agency has conducted a review of th e available product chemistry, environmental fate, and ecotoxicity data for bronopol

. The primary source of information for this assessment

w as the 1995 Bronopol RED. The findings are summarized below.

Product Chemistry Summary ( 99% TGAI)

Common Name: Bronopol

Chemical /CAS Name: 2

- Bromo

- 2

- nitro

- 1,3

- propanediol

IUPAC Name: 2

- Bromo

- 2

- nitropropane

- 1,3

- diol

Trade Name s : Bioban; Rocima ; Onyxide 500 , others CAS Registry Number: 52

- 51

- 7

OPP Chemical Code: 216400

Case: 2770

Molecular Formula: C 3 

### H 6 

### BrNO 4 

### M olecular weight: 199.987 g/mol

Molecular Structure:

Color: White to pale yellow

Physical State: Crystalline solid

Odor: Odorless

Stability : Stable to normal temperature, but at 140°C exothermic decomposition occurs.

Oxidation/Reduction: C an be reduced electronically and has some weak oxidizing potential of no practical significance.

Flammability

- Flash Point : Non

- flammable

Explodability : Not explosive

### 3 of 2 2 Storage Stability : Storage stability tests on a batch of bronopol (initially 100% pure) showed no degradation after 52 weeks at 20 to 25°C and 45°C (both at normal relative humidity). At 90% RH and 20 to 25°C the bronopol content was 99.2%.

Miscibility : N/A

Corrosion Characteristics : Pure bronopol has very little potential to corrode but increasing the

sodium bromide and water content increases the possibility of corrosion of materials such as mild steel, galvanized iron, cast iron

and a luminum.

Dielectric Breakdown V oltage : 

### N/A

pH: 4.5 to 7.0 (1% solution at 20 ° C)

UV/Visible A bsorption : N/A

Viscosity : N/A, Bronopol is a crystalline solid

.

Melting Po int : About 130°C

.

Boiling Point: N/A

. At temperatures above 140°C Bronopol wi ll decompose

.



### Density: 9.18 lb/US Gallon (1.1 g/cm 3 

### ) Specific Gravity: 1.1

Dissociation Constant : Not applicable as bronopol degrades above pH 7.0. An experimental pKa of 9.56 is likely to be a composite pKa associated with bronopol and its decompositi on products.

Log K
ow 

### : 0.18 at 20°C

Solubilit ies : Soluble in water (280 g/l) and organic solvents

Water: 28% @ 22

- 25°C (2.5 x 10 5 

### mg/L)

Ethanol: 58% Propylene glycol: 52%

Vapor Pressure : 1.26 x 10 - 5 

### mm Hg at 20°C

1.68 x 10 - 3 

### Pa (20°C)

Henry's Law C onstant : 1.3 x 10 - 11 

### atm

- m 3 

### /mole at 25 °C

Enf orcement Analytical Method: HPLC IR Spectroscopy

### 4 of 2 2 Gas chromatography

Thin

- layer chromatography

All product chemistry data requirements have been satisfied for the active ingredient bronopol

. ( Source: MRIDs 108 808, 141875, 141876, 163783, & 45199101)

.

Environmental Fate Summary

The Agency has reviewed two environmental fate studies for bronopol and the environmental fate guideline study r esults are summarized in Table 1 and the degradates are

listed in Table 2 . The Agency's conclusions for the degradation studies are as follows.

Degradation Studies ( Abiotic)

a. Hydrolysis

An adequate hydrolysis study exists. Hydrolysis is strongly correlated with temperature and pH. Hydrolysis may or may not occur appreci ably, depending on conditions. An acceptable study, conducted under conditions different from the Agency's present testing guidelines, concluded that bronopol is stable against hydrolysis in "typical" natural settings. At elevated

temperatures (30, 40, 50, and 60°C), in ambient laboratory light and at concentrations of 2000 ppm or higher, the half

- li ves w ere extrapolated to be the following at 20°C: about 18 years at pH 4, about 1.5 years at pH 6, and approximately 2 months at pH 8. At higher temperatures a nd/or pHs, as may occur in industrial applications, hydrolysis is greatly accelerated. At 60°C (140°F),

half

- lives range d roughly from 4 days at pH 4 to only 3 hours at pH 8. This degradation is based on heat decomposition, not hydrolysis. Under accelerate d conditions, degradation is extensive, and formaldehyde is a major hydrolysate. Other degradates produced under these circumstances

are 2

- hydroxymethyl

- 2

- nitropropane

- 1,3

- diol (T ris Nitro ); 2

- bromo

- 2

- nitroethanol; unidentified products which were possibly polymers ; bromide ion ; nitrite (not nitrate); and other trace products such as aliphatic nitro compounds and lightweight gases, but not carbon dioxide (MRID

No s

. 00164535 and 00163783)

.

b. Photodegradation in water

A partially satisfactory photodegrada tion in water study indicates that bronopol rapidly photodegrades at pH 4 under continuous xenon irradiation at 25 ° C ; approximately one

- half of its activity remained after about 24 hours. An equivalent exposure time under natural sunlight would be approxim ately 2 days (assuming 12 hours each of light and dark). Tris (2

- hydroxymethyl

- 2

- nitropropane

- 1,3

- diol), also named tris

- hydroxymethyl

- nitromethane, was a tentatively identified major degradate (up to about 60 percent), which appears to further degrade,

bu t at a slower rate. Another major, but unidentified, "relatively polar" product (component "B") steadily increased, and at the end of the 168 hour (one week) study was up to about 30 percent of the dose. Component "B" was not the putative degradate, 2

- brom o

- 2

- nitroethanol. Steadily increasing levels of labeled carbon dioxide derived from the central carbon atom of bronopol

indicate that at least one reaction leads to extensive degradation. Although carbon dioxide

### 5 of 2 2 increased in parallel with the unknown compo nent "B," formation of component "B" and carbon dioxide appear s to occur by separate pathways (MRID 429413

- 03)

.

Table 1 . Environmental Fate Data Summary for Bronopol

OPP

Guideline Fate Studies Half

- Life Degradates Study Status

161

- 1 Hydrolysis pH 4 pH 6 pH 8 18 years 1.5 years

2 months

Stable at pH 4, 6, & 8 at 20 ° C. Minor D egradates: Formaldehyde

Bomonitroethanol

Tris Nitro Acceptable

MRID 00164535

00163783

Acc # 265943

161

- 2 Aqueous Photolysis at pH 4 24.3 hours (equivalent to 2 days under na tural sunlight conditions) at 25°C

. T hree Major photodegradate s : 1. Tris

- (hydroxymethyl)

- nitromethane. 2. Unidentified relatively polar major degradation product.

3. CO 2 Supplemental

MRID 429413

- 03



### Table 2 . Degradates of Bronopol

Hydrolysates

(Tris

- Nitro)

Formaldehyde Photoproduct s :

(Tris

- Nitro)



### The Agency did not conduct an environmental fate assessment for bronopol because of

lack of data

. However, the Agency needs to conduct an environmental fate assessment for material preserva tives (including bronopol ) and industrial slimicides used in recirculating water cooling towers and paper mills that may potentially pass through waste water treatment plants (WWTPs) and may be discharged into terrestrial and aquatic environments. For thi s assessment the Agency anticipates needing those data outlined on page 1 1 of this document

.

### 6 of 2 2 Water Quality

Bronopol 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 i nformation provided at the Agency’s National Pesticides Cause of Impairment of Waters website (searched April 7, 2011) 2



### . In addition, no Total Maximum Daily Loads (TMDL) have been developed for Bronopol, based on information provided at the Agency’s Nation al Pesticide TMDL web site (searched April 7, 2011) 3



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

. The Agency invites submission of water 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 M anagement 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 pes ticide risk assessments.

Ecological Effects Summary

The registrant has submitted ecological effects studies for both terrestrial and aquatic animals. These data are adequate to provide the Agency with sufficient information to determine appropriate labe l precautions, and may be seen in Tabl e 3

.

a. Toxicity to Terrestrial Animals

(1) Birds, Acute and Subacute

Bronopol is slightly toxic to birds on a n acute oral basis; and practically nontoxic to slightly toxic to birds on a subacute dietary basis.

(2) Mammals

Bronopol is moderately toxic to mammals on an acute oral basis.

There were no developmental effects that could be attributed to the administration

of bronopol

.

Systemic toxicity was observed mostly in the mid

- dose (70 mg/kg/day) and high

dose ( 200 mg/kg/day) groups, in both generations. Reproductive toxicity was observed only in the high

- dose group as evidenced by a slight decrease in the female fertility index during the F 1a 

### mating (75% vs 87.5% in the controls).

2

. http://iaspub.epa.gov/tmdl_waters10/attains_nation_cy.c ause_detail_303d?p_cause_group_id=885

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

### 7 of 2 2 b. Toxicity to Aquatic Animals

(1) Freshwater Fish and Estuarine/Marine Fish

Bronopol is not more than slightly toxic to cold / warm water fish and marine fish

.

F reshwater fish early

- life stage toxicity study is classified as supplemental and

m a y potentially underestimate the sensitiv ity of f reshwater fish to bronopol. Further testing listed on page 10 of this document are required

.

(2) Freshwater and Estuarine/Marine Invertebrates

Bronopol is moderately toxic to freshwater invertebrates and moderately to highly

toxic to estuarine/ma rine invertebrates

.

c. Toxicity to Aquatic Plants

Aquatic p lant toxicity data are classified as supplemental and may potentially underestimate the sensitivity of aquatic plants to bronopol. T herefore, further plant toxicity testing listed on page 1 1 of this document are required

.

Algal toxicity data indicate that bronopol is detrimental at less than 1.0 ppm to

freshwater green algae and freshwater diatoms. Therefore, seedling emergence and vegetative vigor, Tier II

- dose response studies listed on page 1 1 of this document are required.

Table 3 . Ecotoxicity Data Summary for Bronopol

MRID COMMON

NAME TAXONOMIC GUIDE

LINE TYPE % AI STUDY

TIME DOSE

TYPE TOXI

CITY TOX

LEVEL NOEL STUDY

STATUS TOX CATEGORY

Avian Acute Oral Toxicity

00104689 Mallard

duck An as platyrhynchos 850.2100 ( 71

- 1 ) O 99.4 14 day LD 50 509 mgk 100 Acceptable Slightly toxic

Avian Subacute Dietary Toxicity

00148562 Bobwhite quail Colinus virginianus 850.2200 ( 71

- 2a ) D 100 8 day LC 50 4487 ppm 500 Acceptable Slightly toxic

00148941 Mal lard

duck Anas platyrhynchos 850.2200 ( 71

- 2b ) D 100 8 day LC 50 >10000 ppm N.R. Acceptable Practically non

- toxic

Freshwater Fish Acute Toxicity

247196 Rainbow

trout Oncorhynchus mykiss 850.1075 ( 72

- 1 ) S 99.4 96 hr LC 50 20 ppm 10 Supplemental Slightly to xic

00148563 Rainbow

trout Oncorhynchus mykiss 850.1075 ( 72

- 1 ) F 100 96 hr LC 50 41.5 ppm 23 Acceptable Slightly toxic

00148940 Bluegill

sunfish Lepomis

macrochirus 850.1075 ( 72

- 1 ) F 99.7 96 hr LC 50 36 ppm 20 Acceptable Slightly toxic

Estuarine/Marine F ish Acute Toxicit y

00148939 Sheepshead

minnow Cyprinodon variegatus 850.1075 ( 72

- 3 ) F 99.7 96 hr LC 50 59 ppm 18 Acceptable Slightly toxic

### 8 of 2 2 MRID COMMON

NAME TAXONOMIC GUIDE

LINE TYPE % AI STUDY

TIME DOSE

TYPE TOXI

CITY TOX

LEVEL NOEL STUDY

STATUS TOX CATEGORY

Freshwater Invertebrate Acute Toxicity

00098404 Water flea Daphnia

magna 850.1010 ( 72

- 2 ) S 99.4 48 hr EC 50 1.6

1.4 ppm 0.56 Acceptable Moderately toxic

Freshwater Fish Early

- Life Stage Toxicity



### - Embryo to juvenile (swim

- up fry)

45838101 Rainbow

trout Oncorhynchus mykiss 850.1400

( OECD 210 ) F 99.8% 49 day LC 50

LOAEC 39

40

nominal

7.48

mean measured ppm

21

nom inal

1.94

mean measured Supplemental

Estuarine/Marine Mysid Acute Toxicity

- Invertebrates

00150674 Mysid Shrimp Americamysis

bahia 850.1035 ( 72

- 3 ) F 99.7 96 hr LC 50 5.9 ppm 2.4 Acceptable Moderately toxic

Estuarine/Marine Oyster Acute Toxicity (Shel l Deposition)

- Invertebrates

46965403 Eastern Oyster Crassostrea virginica 850.1025 F 99.7 96 hr EC 50 0.35 ppm 0.15 Supplemental Highly toxic

Estuarine/Marine Bivalve (Oyster) Acute Toxicity (embryo larval)

– Invertebrates

00148979 Pacific

oyster Cras sostrea gigas 850.1055 ( 72

- 3b ) S 99.7

Tech 48 hr EC 50 0.78 ppm 0.16 Acceptable Highly toxic

Freshwater Aquatic Vascular Plant Toxicity

47178202 Duckweed Lemna gibba 850.4400 S 99.7 7 d ay EC 50 38 ppm 5.4 Supplemental Toxic

Algal T oxicity

47178203 Mar ine

diatom Skeletonema

costatum 850.5400 99.7 96 hr EC 50 180 ppb 120 Supplemental Detrimental effects

47178204 Freshwater

diatom Navicula pelliculosa 850.5400 99.7 96 hr EC 50 419 ppb 212 Supplemental Detrimental effects

47178205 Freshwater Green alga e Scenedesmus subspicatus 850.5400 99.7 96 hr EC 50 20 ppb 12 Supplemental Detrimental effects

47178206 Freshwater Bluegreen algae Anabaena flos

- aquae 850.5400 99.7 96 hr EC 50 34 ppb 12 Supplemental Detrimental effects

47256602 Freshwater Green algae Selenastrum capricornutum 850.5400 98.6 96 hr EC 50 220 ppb 65 Supplemental Detrimental effects

Mammalian Acute Oral Toxicity

00098396 Rat 87 0.1100 ( 81

- 1 ) 99 LD 50 LD 50 307(M) 342(F) mg/kg

bw Acceptable Moderatetly toxic (II)

Mammalian Subchronic Oral Toxicity

- Rats

00098384 Rat 870.3100 98.8 13 wks LO EL 80 mg/kg

bw /day 20 Acceptable Sever gastro

intestinal irritant. Mammalian Subchronic Oral Toxicity

- Dogs

00098399 Beagle dogs 870.3100 99.2 13 wks LO EL 20 mg/kg

bw /day 8 Acceptable

T wo

- Generation Reproductive Toxicity in Rats

40660901

41916502

40660907 C harles

River COBS

CD strain

R at 870.3800

83

- 4 99.9 LOEL

for systemic

toxicity 70 mg/kg

bw /day 25 Acceptable Systemic toxicity at 70 mg/kg/day dose: increase in kidney weight; decreased liver weight; and

increased incidence of nephropathy.

### 9 of 2 2 MRID COMMON

NAME TAXONOMIC GUIDE

LINE TYPE % AI STUDY

TIME DOSE

TYPE TOXI

CITY TOX

LEVEL NOEL STUDY

STATUS TOX CATEGORY

LOEL

for

r eproductive

toxicity 20 0 mg/kg

bw /day 7 0 Acceptable Systemic toxicity at

200 mg/kg/day dose: decreased body weights; decreased food consumption; increases in organ weights (adrenals, kidneys and thyroid/parathyroid);

decreases in liver weight; and an

increased incidence of nephropathy.

Reproductive toxicity was observed only at 2 00 mg/kg

- bw/ day dose: slight decrease in the female fertility

index.

Oral Developmental T oxicity

43598701

4360 8 501 Sprague

Dawley

Rats 83

- 3 98 (99.5) LO EL

Maternal

Develop

mental mg/kg

bw/ day

> 80

> 80 Acceptable There were no developmental

e ffects that could be

attributed to the

administration of bronopol

.

42319601

42648201 New

Zealand

White

R abbits 83

- 3 L O EL

Maternal Toxicity

Develop

m ental Toxicity 80

80 mg/kg

bw/day

40

40 Acceptable The effects observe d only in the 80 mg/kg/day group

include decreased fetal body weight in both sexes (10%),

and an increase in fetuses with major

external/visceral and

skeletal abnormalities (6.9%

- 29.5%).

In

- vitro Bacterial Mutagenicity Testing (Ames Test)

40660902

9219 8025 Salmonella Salmonella typhimurium strains TA1535, TA1537, TA1538, TA98

and TA100, with

and without

metabolic

activation. 870.5140

84

- 2(a) 99.7 Acceptable Negative for muta

genicity in the Ames

test. The highest

concentrations of bronopol teste d were

125 ug and 62.5 ug/plate, in the presence and absence

of S

- 9, respectively.

Concentrations of bronopol higher than

these tested were too

toxic for Salmonella
Test Type

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

- through

Tox Level

— mgk : milligrams per ki logram

- 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); ppb : parts per billion (equivalent to micrograms per liter (μg/L) for aquatic e xposure) Categories of acute toxicity for aquatic organisms (U.S. EPA, 2004) based on E C 50 / LC 50 (mg/L): < 0

. 1 very highly toxic; 0.1

- 1 highly toxic; > 1

- 10 moderately toxic; > 10

- 100 slightly toxic; > 100 practically nontoxic. Toxicity categories for terrestr ial plants have not been defined. 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. LD50 (mg/kg bw): < 10 very highly toxic; 10

- 50 highly toxic; 51

- 500 moderately toxic; 501

- 2000 slightly toxic; >2000 practically non

- toxic.

### 10 of 2 2 Adverse Ecological Incidents

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

. However, t he absence of documented incidents does not necessarily

mean that such incidents did not occur.

Ecological Effects Risk Assessment

An ecological risk assessment was not conducted on the bronopol’s use patterns described in this document. Bronopol uses that have potential for environmental exposure are material preservatives, and industrial slimicides used in recirculating water cooling towers and paper mills discharges. The Agency anticipates cond ucting environmental fate and ecological

risk assessments for material preservatives and industrial slimicides used in recirculating water cooling towers and paper mills that potentially pass through waste water treatment plants (WWTPs) and may be discharg ed into terrestrial and aquatic environments. For this ecological risk assessment, including an endangered species assessment for all uses, t he Agency anticipates needing the plant toxicity data outlined on page 1 1 of this document

.

The Agency has not co nducted a risk assessment for bronopol that supports a complete endangered species effects determination. The ecological risk assessment planned during registration review will allow the Agency to determine whether bronopol ’s use has “no effect or “may af fect” federally listed threatened or endangered species (listed species) or their designed critical habitats. When an assessment concludes that a pesticide’s use “may affect” a listed species or its designated critical habitat, the Agency will consult wit h the U.S. Fish and Wildlife Service and/or National Marine Fisheries Services (the Services), as appropriate.

### 11 of 2 2 Environmental Fate and Ecotoxicity Data Gaps and Anticipated Work

Environmental fate and ecological risk assessments have not been conducted fo r bronopol. The Agency anticipates conducting environmental fate and ecological risk assessments for material preservatives, and industrial slimicides used in recirculating water cooling towers and paper mills that potentially pass through waste water tre atment plants (WWTPs) and may be discharged into terrestrial and aquatic environments. Therefore, the Agency anticipates needing the proposed environmental fate and ecotoxicity data for bronopol and/or any of its major degradation products that are of pot ential concern for all registered uses of bronopol. The following environmental fate and ecotoxicity data are needed to conduct an environmental fate and ecological risk assessment:

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

environmental fate assessment for material preservative use, industrial slimicides used in recirculating water cooling towers and paper mills :

o (GLN 850.6800) Modified Activated Sludge Respiration Inhibition ;

o (GLN 835.3110) Ready Biodegradability , (GLN 835 .3220) Porous Pot Test , or (GLN 835.3280) Simulation Tests to Assess the Biodegradability of Chemicals Discharged to Wastewater 4



### .

**•** The Agency anticipates needing t he following ecological effects data in order to conduct a complete ecological risk assessme nt, including an endangered species

assessment for industrial slimicides used in recirculating water cooling towers and paper mills and material preservative uses of bronopol :

o (GLN 850.1300) Daphnid chronic toxicity test ;

o (GLN 850.1400) Fish early

- life st age toxicity test ;

o (GLN 850.4225 ) seedling emergence, Tier II

- dose response study on rice ( Oryza

sativa );

o (GLN 850.4250 ) vegetative vigor, Tier II

- dose response study on rice ( Oryza

sativa );

o (GLN 850.4400 ) aquatic plant growth (aquatic vascular plant t oxicity), Tier II

- dose response study on floating macrophyte Lemna gibba ; and

o (GLN 850.5400 ) aquatic plant growth (algal toxicity), Tier II

- dose response

studies on Selenastrum capricornutum (green alga), Anabaena flos

- aquae (blue

green cyanobacteria) , Navicula pelliculosa (freshwater diatom), and Skeletonema costatum (marine diatom ).

4 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.

### 12 of 2 2 

## Appendix A. Environmental Fate Guideline Study J ustifications

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

will use these data to determine the potential impact of this chemical on waste water treatment plants (WWTPs) as a result of respiration inhibition of activated sludge microorganisms. This te st is also necessary to enable EPA to establish correc t concentrations for use in the biodegradability test, if that test is determined to be adequate for assessing biodegradation potential. Furthermore, the results of the Activated Sludge Respiration Inhi biti on 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) Biodegradation 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 Activated Sludge or the Porous Pot study is required.

Practical Utility of the Data

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

the data will be used to determine whether or not label restrictions are needed. The study will identify the inhibitory effect of this chemical on the treatment plant’s microorganisms’ respiration at different concentrations of the test substance and will identify the EC 50 

### , the effective concentration of the test substance at which the respiration rate is 50% of that shown by the control under conditions in this guideline

. The data will also determine suitable non

- inhibitory concentrations to be used in biodegradability tests.

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

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

### 13 of 2 2 Guideline Number s : 835.3110, 835.3220, or 835.3280 Study Title s : Ready Biodegradability , Porous Pot Test , or Simulation Tests to Assess the Biodegradability of Chemicals Discharged to Wastewater (also referred to as Biodegradation in Activated Sludge), respectively Rationale for Requiring the Data For antimicrobial chemicals that go down

- the

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

- level environmental fate assessment, EPA will analyze the potential impact of the antimicrobial chemical on the microorganisms in the biological treatment processes of a WWTP. Biodegradation is an important environmental pathway in which the antimicrobial is broken down by bacteria. This study results suppl y information on the rate of biological breakdown and the completeness of the degradation to carbon dioxide and water. A ready biodegradability study would allow t he Agency to determine whether or not t he chemical achieves ‘‘pass levels’’ for ready biodegradability (e.g., 70% removal of dissolved organic carbon). The results of the Activated Sludge Respiration Inhibition Test (ASRI) determine which of these

three biodegradation tests are required. If the ASRI test EC 50 

### is less than or equal to 20 mg/L, then either the Biodegradation in Activated Sludge Study or the Porous Pot Test is required. If the ASRI test EC 50 

### is greater than 20 mg/L, then the applicant must choose either: (i) Ready Biodegradability or (ii) Biodegradation in Activated Sludge or the Porous Pot Test. If the antimicrobial passes the ready biodegradability study, then no further testing is required. If, however, the antimicrobial fails the ready biodegradability study, then the Biodegra dation in Activated Sludge or the Porous Pot study is required. Practical Utility of the Data

1. How will the data be used? The data from a biodegradation study will be used to determine the percent removal of the antimicrobial as a result of biodegrada tion 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 concentratio ns 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 the impact of pesticides to beneficial non

- target organisms through direct exposure from their

food sources and habitat.

In addition, the data will be used to determine whether or not additional studies and/or label restrictions

are needed. If the chemical does not achieve a ‘‘pass level’’ for ready 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 readily biode graded, 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 aquatic

organ isms to determine concentrations of antimicrobial pesticide downstream of wastewater treatment plants. If high inhibition of activated sludge microorganisms (i.e., EC50 less than or equal to 20 mg/L) is determined in an activated sludge respiration inhibi tion 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 biodegrad ation, the

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 for the pro ducts to meet the “no unreasonable adverse effects” requirements of FIFRA (e.g., changes to the directions for disposal).

### 14 of 2 2 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 jeopar dize 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 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 no t harm endangered species and may therefore need to consider other limitations on the use of the pesticide in order to fulfill the Agency’s statutory obligations under the ESA. The lack of these data will limit the flexibility that the Agency and registra nts have in coming into compliance with the ESA and could result in use restrictions which are unnecessarily severe.



## Appendix B: Ecological Guideline Study Justifications

Guideline Number: 850. 1300 Study Title: Daphnid chronic toxicity test

Practical Ut ility of the Data 1) What is the value of the study? Invertebrates serve as food for fish, birds, crustaceans, and even whales. The protection of non

- target invertebrates is essential to the food chain in any healthy ecosystem. The value in the Daphnid (850.1300) and Mysid (850.1350) chronic toxicity tests are that they provide information on the effects of pesticides on mortality, growth, and reproduction over a longer term (21 days for Daphnids and 28 days for Mysids) compared to acute studies. Data a re obtained from the first generation (G1) and the second generation (G2), thus allowing examination of the complete invertebrate life cycle for toxicity.

2) How would the data be used?

Data would be used to calculate LC 50 

### ’s for mortality, EC 50 

### ’s for grow th, a NOAEC, and a MATC (maximum acceptable toxicant concentration). The data would allow the Agency to determine chronic effects, including effects on reproductive success and growth, to freshwater invertebrates from water column exposure to bronopol

.

3 ) How could the data affect the risk assessment? Because acute toxicity data alone are not a reliable indicator of chronic toxicity, chronic toxicity data are also required. The Agency cannot make the assumption that a chemical is not chronically toxic at

much lower concentrations than some ratio of the LC 50 

### value would suggest. The results 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 e ffects on organisms which feed on them. Daphnia magna (for fresh water) is used to represent all invertebrate species living in the water column in the risk assessment process. Additionally, the use of the most sensitive species ensures the protection of other species within that taxon. As part of the chronic risk assessment for aquatic animals, the lowest NOAEC for estuarine/marine invertebrates is used in the RQ equation. A chronic LOC is defined by an RQ > 1, and would indicate that there is the pote ntial for chronic risk that may warrant regulatory action and that endangered species may potentially be affected through chronic

exposure.

4) What is triggering the need for this data? Data are needed in order to conduct an ecological risk assessment for the use of bronopol as a slimicide in recirculating water cooling towers and paper mills and determine the chronic toxicity of bronopol to freshwater and marine invertebrates using life

- cycle studies. Also data are needed in order to conduct an ecologica l risk assessment for material preservative use pattern of bronopol

.

### 15 of 2 2 Guideline Number: 850. 1400 Study Title: Fish early

- life stage toxicity test
Practical Utility of the Data 1) What is the value of the study? Fish early

- life stage study is less expen sive to conduct than the full life cycle study. Fish early

- life stage study gives us some indications if the pesticide is toxic to fish reproduction and survival. In the fish early

- life stage study, fertilized eggs are placed in test chambers and exposed to the pesticide in

water at least until all the control fish are free

- feeding. Lethal and sublethal effects are assessed and compared with control values to determine the LOAEC and the NOAEC.

2) How would the data be used?

The data are used to determin e embryo hatch rate, time to hatch, time to swim

- up, growth (length and weight), and any clinical or pathology findings.

3) How could the data affect the risk assessment? As part of the chronic risk assessment for aquatic animals, the lowest NOAEC for est uarine/marine fish is used in the RQ equation. A chronic LOC is defined by an RQ > 1, and would indicate that there is the potential for chronic risk that may warrant regulatory action and that endangered species may potentially be affected through chroni c exposure.

4) What is triggering the need for this data? Data are needed in order to conduct an ecological risk assessment for the use of bronopol as a slimicide in recirculating water cooling towers and paper mills and determine the effects of bronopol on fish development and survival during early life stages. Also data are needed in order to conduct an ecological risk assessment for material preservative use pattern of bronopol

.

### 16 of 2 2 Guideline Number: 850.4225 Study Title: Seedling emergence, Tier II

- d ose response using rice ( Oryza sativa )
Practical Utility of the Data 1) What is the value of the study? Plants prevent erosion and provide animals with food and shelter. The rooted aquatic plant, rice is used to represent exposure to all vascular rooted plants. Tier II (Definitive Studies) tests are initiated following a determination that a greater than 25% adverse effect occurred in the Tier I (Initial Screening Study) seedling emergence study for one or more plant species. These Tier II terrestrial nontarget plant phytotoxicity tests evaluate the acute toxicity of pesticides to 10 crop plant species, including six Dicots and four Monocots. Although rice ( Oryza sativa ) is not one of the surrogate terrestrial crop plants typically tested, its semiaqua tic environment is applicable to run

- off scenarios. If conducting tests under TSCA, the test material is applied daily with each watering for the duration of the study. Observations are carried out for at least 14 days after seedling emergence.

2) How w ould the data be used? Along with vegetative vigor studies, results of these studies will be used to assess risks to of bronopol exposure to terrestrial, semiaquatic, and aquatic nontarget plants. Parameters of plant growth include percent emergence, numb er of emerged plants, seedling height, seedling dry weight, root length, root dry weight, and signs of phytotoxicity. Results are reported as EC 05 

### (NOAEC), EC 25 

### , and EC 50



### .

3) How could the data affect the risk assessment? Because bronopol would not be di rectly applied to the field, information on environmental fate and transport would affect the risk identification and characterization to non

- target plants. Nontarget plants include plants outside the area of intended application (which would typically in clude food and cover vegetation for animals, food, fiber, fuel, and ornamental plants for humans, and endangered and threatened plants). Terrestrial plants serve as food and shelter for fish and wildlife, help control erosion, and serve as air pollution f ilters. Shoreline vegetation buffers reduce siltation and provide an environment in which aquatic invertebrates can contribute to the food supply of fish, reptiles, and amphibians. Vegetation adjacent to streams serves to regulate water temperature, whic h in turn contributes to improved aquatic life. Decaying vegetation provides nutrients essential for the aquatic food chain. Hedgerows, woodlots, and other similar nontarget areas provide food and cover to mammalian and avian species.

There are many ter restrial plants that may be affected where bronopol is used as a slimicide in recirculating water cooling towers and paper mills . If EPA is unable to evaluate the potential risks to terrestrial plants associated with the new use of bronopol, these risks m ust be presumed. As part of the risk assessment for terrestrial plants (non

- endangered and endangered), the lowest EC 25 

### for monocots and dicots is used in the RQ equation. The LOC for endangered and non

- endangered plants is defined as a RQ > 1.

4) What is triggering the need for this data? Data are needed in order to conduct an ecological risk assessment for the use of bronopol as a slimicide

in recirculating water cooling towers and paper mills and determine the effects of bronopol on seedling

emergence

.

### 17 of 2 2 Guideline Number: 850.4250 Study Title: Vegetative vigor, Tier II

- dose response using rice ( Oryza sativa )
Practical Utility of the Data 1) What is the value of the study? Plants prevent erosion and provide animals with food and shelter. The root ed aquatic plant, rice is used to represent exposure to all vascular rooted plants. Tier II (Definitive Studies) tests are initiated following a determination that a greater than 25% adverse effect occurred in the Tier I (Initial Screening Study) vegetativ e vigor study for one or more plant species. These Tier II terrestrial nontarget plant phytotoxicity tests evaluate the acute toxicity of pesticides to 10 crop plant species, including six Dicots and four Monocots. Although rice ( Oryza sativa ) is not one of the surrogate terrestrial crop plants typically tested, its semiaquatic environment is applicable to both leaching and

run

- off scenarios. The test material is applied 2 to 4 weeks after the plants have emerged from the soil,

and observations are carri ed out for at least 14 days.

2) How would the data be used? Along with the seedling emergence studies, results of these studies will be used to assess risks to terrestrial and aquatic plants from exposure to bronopol. Parameters of plant growth include p lant height, plant dry weight, root length, root dry weight, and signs of phytotoxicity. Results are reported

as EC 05 

### (NOAEC), EC 25 

### , and EC 50



### .

3) How could the data affect the risk assessment? Because bronopol would not be directly applied to the field, information on environmental fate and transport would affect the risk identification and characterization to non

- target plants. There are many terrestrial plants that are listed as threatened and endangered in the United States where bronopol is

used as a slimicide in recirculating water cooling towers and paper mills . If EPA is unable to evaluate the potential risks associated with the recirculating cooling water systems and paper mills use s of bronopol, these risks must be presumed. As part of the risk assessment for terrestrial plants (non

endangered and endangered), the lowest EC 25 

### for monocots and dicots is used in the RQ equation. The LOC for endangered and non

- endangered plants is defined as a RQ > 1.

4) What is triggering the need for this data? Data are needed in order to conduct an ecological risk assessment for the use of bronopol as a slimicide

in recirculating water cooling towers and paper mills and determine the effects of bronopol on vegetative vigor.

### 18 of 2 2 Guideline Number: 850.4400 Study Title: Aquatic Plant Toxicity Test Using Lemna spp., Tiers II
Practical Utility of the Data 1) What is the value of the study? Aquatic plants are essential components of any healthy ecosystem. Plants provide food, shelter, and oxygen to animal species. Lemna represents floating aquatic macrophytes. As part of a Tier I risk assessment, one freshwater aquatic plant indicator species, ( Lemna gibba or L. minor ), is exposed to a range of concentrations of bronopol in fresh water to measure phytotoxicity.

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

- target plants in aquatic ecosystems. Data from these studies would be used to plot concentration response curves for total frond number, growth rate (as nu mber of fronds per day), and mortality (percentage of dead fronds to total number of fronds). EC 05 

### s, EC 50 

### s, and EC 90 

### s would be calculated from the curves. Tier II (definitive) testing is not required if Tier I testing results in an EC 50 

### greater than 1000 mg/L or less than the analytical detection limit. Tier II tests may also include endpoints such as measurements of chlorophyll pigments, biomass, and more detailed observations of frond appearance (i.e., decrease in size, necrosis, chlorosis, or sinking)

.

3) How could the data affect the risk assessment?

Lemna spp. are used to represent all aquatic plants in the risk assessment process. Adverse effects to

non

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

measures.

Aquatic plants may be affected where b ronopol is used as a material preservative and industrial slimicides used in recirculating water cooling towers and paper mills . If EPA is unable to evaluate the potential risks to aquatic plants associated with the material preservative and industrial sl imicides used in recirculating water cooling towers and paper mills use of bronopol , these risks must be presumed. As part of the risk assessment for aquatic vascular plants, the lowest EC 50 

### is used in the RQ equation. The LOC for endangered and non

- enda ngered plants is defined as a RQ > 1.

4) What is triggering the need for this data? Data are needed in order to conduct an ecological risk assessment for the use of bronopol as a material preservative s and industrial slimicides used in recirculating water cooling towers and paper mills and

determine the effects of bronopol on aquatic plants because they are critical to ecosystem health and productivity. Aquatic plants may be exposed via indoor uses from bronopol used in material preservatives and industria l slimicides used in recirculating water cooling towers and paper mills that pass through WWTPs.

### 19 of 2 2 Guideline Number: 850.5400 Study Title: Algal Toxicity, Tier II ( Selenastrum capricornutum, Anabaena flos

- aquae, Navicula pelliculosa and Selenastrum Capri cornutum ) Practical Utility of the Data 1) What is the value of the study? Aquatic plants are essential components of any healthy ecosystem. Plants provide food, shelter, and oxygen to animal species. Green algae, blue

- green cyanobacterium, and diatoms (marine and freshwater), represents thousands of algae species. As part of a Tier I risk assessment for microphytic toxicity, freshwater green algae ( Selenastrum capricornutum ), marine diatom ( Skeletonema costatum ), the freshwater diatom ( Navicula pellic ulosa ), and the blue

- green alga or cyanobacterium ( Anabaena flos

- aquae ) are tested for phytotoxicity.

2) How would the data be used? This study would be used to evaluate the toxicity of bronopol to algae in aquatic ecosystems. The algal growth response ( number or weight of algal cells/mL) is measured at the end of the 96 h test. The percentage inhibition or stimulation of growth for each concentration, concentration response curves, and EC 50 

### s are determined from these data. Tier II (definitive) testing may not be necessary if the highest chemical concentration tested (water saturation concentration or 1000 mg/L) results in less than 50% reduction in growth. However, if the lowest concentration tested (analytical detection limit) results in greater than a 50% reduction in growth, definitive testing is required.

3) How could the data affect the risk assessment? Because algae are critical to ecosystem health and productivity, any adverse effects to algae in aquatic ecosystems may result in mitigation to pr otect species at risk. Mitigation might include reduced label dosages, neutralization of effluents prior to discharge into water, restrictions on use in sensitive ecosystems or where endangered species are present, or other mitigation measures. As part o f the risk assessment for algae, the lowest EC 50 

### is used in the RQ equation. The LOC for plants is defined as a RQ > 1.

4) What is triggering the need for this data? Data are needed in order to conduct an ecological risk assessment for the use of bronopo l as a slimicide in recirculating industrial cooling tower water systems and paper mills and determine the effects of bronopol on algae because they are critical to ecosystem health and productivity. In addition to the environmental outdoor exposure to ef fluent discharges of bronopol from recirculating cooling water

systems, algae species may be exposed via indoor uses from bronopol used in pulp and paper mill

water systems that pass through WWTP. Also data are needed in order to conduct an ecological ris k assessment for material preservative use pattern of bronopol.

### 20 of 2 2 

# Appendix C

Registered Products of Bronopol

Registration # Registration Name Company Name Formulation Type % of Active Ingredient

464

- 675 BiobanTM BP

- Plus

Preservative The Dow Chemical Co

. Ready

- to

- Use

Solution 99

464

- 676 Bioban BP

- 40

Preservative The Dow Chemical Co. Ready

- to

- Use

Solution 40.8

464

- 680 Bioban BP

- 10

Preservative The Dow Chemical Co. Ready

- to

- Use

Solution 10

464

- 685 Bioban BP 30

Preservative The Dow Chemical Co. Ready

- to

- Use

Solution 30

464

- 687 Bioban BP

- M

Preservative The Dow Chemical Co. Technical

Chemical 99

707

- 295 ROCIMATM 607 Rohm & Haas Co. Ready

- to

- Use

Solution 10

707

- 315 ROCIMATM 586 Rohm & Haas Co. Soluble

Concentrate 7.5

1258

- 1290 Proxel BN Preservative Arch Chemicals, Inc. Soluble

Concentrate 6.5

1529

- 58 Nuosept W International Specialty

Products Flowable

C oncentrate 7

1529

- 59 Nuosept W Concentrate International Specialty

Products Soluble

Concentrate 14

3876

- 147 S3876 DE

- 1220 GE Betz, Inc. Ready

- to

- Use

Solution 5.3

3876

- 151 Betz ® DE

- 5556 GE Betz, Inc. Ready

- to

- Use

Solution 5.3

5383

- 106 Mergal K12N Troy Chemical Corp Ready

- to

- Use

Solution 7.1

9386

- 45 AMA ®

- 4900B Kemira Chemicals, Inc, Ready

- to

- Use

Solution 10

10707

- 53 X

- CIDE ® 600 Industrial

Microbiocide Baker Petrolite Corporation Water Soluble Packaging 98.45

33753

- 3 Myacide AS BASF Corporation Technic al

Chemical 99

33753

- 5 Myacide AS Plus BASF Corporation Crystalline 99

33753

- 7 Myacide S2 BASF Corporation Ready

- to

- Use 40.8

### 21 of 2 2 Registration # Registration Name Company Name Formulation Type % of Active Ingredient

Solution

33753

- 17 Myacide S15 BASF Corporation Ready

- to

- Use

Solution 10

33753

- 18 2K7 Bugstick BASF Corporation Pelleted/Tablete d 84.5

33753

- 20 Myacide S30 BASF Corporation Ready

- to

- Use

Solution 30

39967

- 28 Biochek 721M LANXESS Corporation Ready

- to

- Use

Solution 6

39967

- 59 Preventol P 100 LANXESS Corporation Technical

Chemical 99.74

39967

- 61 Preventol P 100

Preservative LANXESS Corporation Soluble

Concentrate 99.74

39967

- 64 Preventol P 30 LANXESS Corporation Soluble

Concentrate 30

39967

- 79 Preventol P 91 LANXESS Corporation Emulsifiable

Concentrate 9.97

49403

- 33 Nipacide GSF

- A Clariant Corporation Ready

- to

- Use

Solution 5.35

6 7071

- 16 Acticide LA Thor GmbH Ready

- to

- Use

Solution 8.8

67071

- 18 Acticide SR 2060 Thor GmbH Ready

- to

- Use

Solution 5.2

67071

- 45 Acticide MBL 5515 Thor GmbH Soluble

Concentrate 15

67071

- 46 Acticide MBL Thor GmbH Ready

- to

- Use

Solution 8

67071

- 50 Acticide LA 2605

- F Thor GmbH Soluble

Concentrate 5.3

67071

- 52 Acticide MBL 5505 Thor GmbH Soluble

Concentrate 5

67212

- 1 BBJ Microbiocide BBJ Environmental, LLC Ready

- to

- Use

Solution 95

67212

- 2 BBJ Maintain C

- 1 For

Floors And Walls BBJ Environmental, LLC Soluble

Concentrate 3.25

67212

- 3 BBJ Mold Control BBJ Environmental, LLC Ready

- to

- Use

Solution .05

67420

- 1 2K7 Bugstick OSP Microcheck Inc Water Soluble 84.5

### 22 of 2 2 Registration # Registration Name Company Name Formulation Type % of Active Ingredient

Packaging

67420

- 2 2K7 Water Soluble Paks OSP Microcheck Inc Crystalline 99

67869

- 37 Vericide Bronopol Verichem, Inc. Crystalline 99

67869

- 38 Vericide Bronopol

Solution Verichem, Inc. Soluble

Concentrate 10

68708

- 9 EC9086A Nalco Company Ready

- to

- Use

Solution 8.8

74655

- 14 Spectrum RX

- 96 Hercules Incorporated Ready

- to

- Use

Solution 5.3