Document ID: EPA-HQ-OPP-2007-0540-0004
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2007-07-18T04:00Z

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

OFFICE OF

                                                                        
                                    PREVENTION, PESTICIDES AND 

                                                                        
                                             TOXIC SUBSTANCES

					

June 28, 2007

MEMORANDUM  

                                                                        

	

SUBJECT:	Environmental Effects Assessment of
beta-bromo-beta-nitrostyrene, 2-bromo-2-niroethenylbenzene
(Bromonitrostyrene) for the Reregistration Eligibility Decision (RED)
Document

Case No.: 2065	DP Barcode: 336286

FROM:	David C. Bays, Microbiologist

Risk Assessment and Science Support Branch (RASSB)

Antimicrobials Division (7510P)

TO:                             		Mark Hartman, Branch Chief

Regulatory Management Branch II

Antimicrobials Division (7510P)

ShaRon Carlisle, Chemical Review Manager

Regulatory Management Branch II

Antimicrobials Division (7510P)

THRU:	Rick Petrie, Team Leader, Team Three

Risk Assessment and Science Support Branch (RASSB)

Antimicrobials Division (7510P)

Norman Cook, Branch Chief

Risk Assessment and Science Support Branch (RASSB)

Antimicrobials Division (7510P)

Chemical Name	                     PC Code                 CAS#         
   	             Common Name

beta-bromo-beta-nitrostyrene       101401                7166-19-0      
         Bromonitrostyrene

 2-bromo-2-nitroethenylbenzene                                       

Environmental Effects Science Chapter and Assessment on
Bromonitrostyrene is submitted for Reregistration Eligibility Decision
(RED).

 ECOLOGICAL HAZARD AND ENVIRONMENTAL 

RISK ASSESSMENT CHAPTER

beta-bromo-beta-nitrostyrene,

2-bromo-2-nitroethenylbenzene

(Bromonitrostyrene)

PC Code: 101401

CASE No.: 2065

05/14/2007

David C. Bays

Antimicrobials Division

Office of Pesticide Programs

U.S. Environmental Protection Agency

1200 Pennsylvania Avenue, NW

Washington, DC 20460



Table of Contents

I.  Summary of
Uses…………………………………………………………
………………4

II.  Ecological Toxicity Data . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Toxicity to Terrestrial Animals . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . 5

1.  Birds, Acute and Subacute
………………………………………………..…5

2.   Mammals, Acute and Chronic . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . 6

3.   Non-target Insects,
Honeybees……………………………………………….6

             

            B.  Toxicity to Aquatic Animals
………..………………………………….………..6 

1.  Freshwater Fish, Acute . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . .   6

2.  Freshwater Fish, Chronic
………………………….………………….…7

3.  Freshwater Invertebrates,
Acute………………….……………………...7

4.  Freshwater Invertebrates, Chronic
………………………………………8

5.  Estuarine and Marine Organisms
………………………………………..8 

              C.  Toxicity to Plants . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..9 

III.  Risk Assessment and Risk Characterization . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . .9

A.  Environmental Fate Assessment Summary . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . 11

B.  Environmental Exposure Assessment
…………………………………………..11

C.  Endangered Species Considerations . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . .  . . . . 18

IV.  Confirmatory Data Required. . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . .. . . . . . 20

V.  Label Hazard Statements for Terrestrial and Aquatic Organisms. . . .
. . . . . . .  . . . .. . . 20

VI.  References . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . .  . . . . . . 20

I.  Summary of Uses  

Bromonitrostyrene (BNS) is an antimicrobial agent inhibits the growth of
bacterial and fungi during the manufacture, storage and distribution of
adhesives, caulks, none-food contact paper coatings, sealants, inks,
dyes, textile lubricants, guar gums, fountain solutions, metalworking
fluids, surfactants, paints, latex emulsions, mineral slurries,
pigments, coatings and consumer household related products such as
dishwashing liquids, surface cleaners, laundry cleaners and polishes. 
The following is an overview of BNS uses:

TYPE OF PESTICIDE

Fungicide, Slimicide, Molluscide, Mildewcide, Algaecide,
Microbiocide/Microbiostat 

CURRENT USES

Commercial, Institutional and Industrial Premises and Equipment

Commercial Laundry

Materials Preservatives

Latex                                                           
Adhesives

Cleansers                                                     Gum
adhesives

Dispersed colors                                          Caulking
compounds

Polishes                                                        Sealants

Solutions (all or unspecified)                       Coatings

Emulsions (all or unspecified)                      Paper/paperboard
coatings 

Liquid products (all or unspecified)             Leather and leather
stock

Inks                                                              
Metalworking cutting fluids

Dyes                                                              Oil
recovery drilling mud and packer fluid

Liquid detergents                                           Paints

Textiles and textile finishes                           Latex paints

Alum solutions                                               Paper and
paperboard products

Starch solutions                                             Wet
lap/sheet pulp

Printing pastes                                               Synthetic
polymers

Slurries

Industrial processes and Water Systems

Brewery pasteurizer water

Pulp and paper mill systems

Industrial disposal water

Cooling tower water

Evaporative condenser water

Secondary oil recovery injection water

Sewage systems

 

Ecological Toxicity Data

A.  Toxicity to Terrestrial Animals

  

                              1.  Birds, Acute and Subacute

For indoor uses, an acute oral toxicity study using the technical grade
of the active ingredient (TGAI) is required to establish the toxicity of
these chemicals to birds.  The preferred test species is either mallard
duck (a waterfowl) or northern bobwhite quail Ian upland game bird). 
Several avian acute toxicity studies were found in the Agency’s files
for this chemical.  Avian acute oral toxicity testing (850.2100/71-1),
preferably using the bobwhite quail, is required to support the
currently registered uses of these chemicals.

    

Avian dietary toxicity studies using the TGAI of these chemicals are not
required for indoor uses.

The results from the avian acute toxicity and dietary studies obtained
from the Agency’s files are summarized in the table below (Table 1).

Table 1  

Test and Organism  	Results LC50 (mg/L) or LD50 (mg/kg)	Toxicity
Category	Comments	Reference

Eight day dietary LC50 Mallard Duck (Anas platyrhynchos)	>5620

NOEC = 3160	Practically non-toxic	Core study	Grimes and Jaber, 1987

MRID# - 406413-04

Eight day dietary LC50 Bobwhite Quail (Colinus virginianus)	>5620 

NOEC  = 3160	Practically non-toxic	Core study	Grimes and Jaber, 1987 

MRID# - 406413-05 

Acute Oral Toxicity LD50 Mallard Duck (Anas platyrhynchos) 	>500  Birds
regurgitated test substance after 15 minutes	Not given	Supplemental
Study

	Grimes and Jaber, 1987

MRID# - 406413-03

The results of the dietary avian studies indicate that BNS is
practically non-toxic to both mallard duck and bobwhite quail.  In the
acute oral study, the chemical did not cause any deaths, but the birds
regurgitated the test substance within 15 minutes.  Therefore the study
was considered supplemental and did not satisfy guideline requirements. 
The dietary studies were considered to be core and met guideline
requirements at the time they were submitted to the Agency. 

                      

                           2.  Mammals

A summary of mammalian toxicity of BNS is presented in the “Evaluation
of Toxicity Database for Reregistration Eligibility Decision Document
Disciplinary Chapter”.

  3.  Non-target Insects, Honeybees

Honeybees should not be exposed to BNS because of the indoor use
patterns of this pesticide. Therefore the honeybee contact LD50 test
testing is not required.

       

 B.  Toxicity to Aquatic Animals

                                  1.  Freshwater Fish, Acute

Freshwater fish toxicity studies using the TGAI are required to
establish the toxicity of  these chemicals to fish.  Data are generally
required for only one species.  Testing in two fish species is required
for stable chemicals with high volume effluents (e.g., including, but
not limited to, egg washing, fruit and vegetable rinses, swimming pools
or materials preservatives) and if the LC50 in the first species is
greater than (>) 1 ppm.  The preferred test species are rainbow trout (a
coldwater fish) and bluegill sunfish (a warmwater fish), although other
test species identified in the OPPTS Guideline (i.e., OPPTS 850.1075
(e)(4)(i)(A)) may also be used.  Several freshwater fish acute toxicity
studies were identified from peer-reviewed literature (Table 2). 
Several freshwater fish acute toxicity studies were found in the
Agency’s files (Table 3).    Freshwater fish acute toxicity testing
(850.1075/72-1) on one species, preferably the rainbow trout, is
required to support the currently registered uses of this chemical.

`	

The results from freshwater fish acute toxicity studies obtained from
the Agency’s files are summarized in the table below (Table 2).

Table 2 

Test and Organism 	Results LC50 (mg/L)	Toxicity Category	Comments
Reference

Acute Toxicity LC50 Rainbow Trout (Salmo gairdneri)	96 hour LC50 =    27
ug a.i./l

NOEC = 13 ug a.i./l 	Very highly toxic	Core	Sousa, J. 1989

MRID# - 411648-02

Acute Toxicity LC50 Bluegill Sunfish (Lepomis macrochirus)	96 hour LC50
= 17 ug/l

NOEC = 10 ug/l	Very highly toxic	Core	Bowman and Stuerman, 1990

MRID# - 416035-05

                                 

As shown in Table 2, the acute toxicity was 27 ug a.i./l for rainbow
trout and 17 ug/l for bluegill sunfish. This classified BNS as being
very highly toxic to both warmwater and coldwater fish species.

 

                             2.  Freshwater Fish, Chronic

Fish early life stage testing is required for the currently registered
once-through industrial water systems use of this chemical.

One study was submitted for this chemical (Table 3).

 

Table 3

Test and Organism	Results	Toxicity Category	Comments	Reference

Freshwater fish early life-stage toxicity test  Fathead Minnow

Pimephales   promelas)	MATC = >8.9 and >20 ug a.i./l 

Geometric mean MATC = 

13.3 ug a.i./l	None given	Core	Cohle, P. and Stratton J. 1992

MRID# - 423997-01

Based on the hatchability, survival, and growth data form this 35-day
fathead minnow early life stage study, the NOEC and LOEC were 8.9 and 20
ug a.i./l, respectively.   

                             3.  Freshwater Invertebrates, Acute        

A freshwater aquatic invertebrate toxicity test using the TGAI is
required to establish the toxicity of a pesticide to aquatic
invertebrates.  The preferred test species is Daphnia magna or Daphnia
pulex.   One study testing these organisms was found in the Agencies
files (Table 4).  Freshwater invertebrate acute toxicity testing
(850.1010/72-2) is required for the currently registered uses of this
chemical. 

Table 4

Test and Organism	Results 	Toxicity Category	Comments	Reference

Freshwater invertebrate flow through acute toxicity  Daphnia magna
48-hour EC50 = 24 ug a.i./l  

NOEC = 14 ug a.i./l	Very highly toxic	Core	McNamara, P.C. 1989

MRID# - 411648-01

As shown in Table 4, this chemical is very highly toxic to aquatic
invertebrates.  

 

                               4.  Freshwater Invertebrates, Chronic  

Chronic aquatic invertebrate testing is not required for the currently
registered uses of this chemical.  

   

                               5.  Estuarine and Marine Organisms

Acute toxicity testing with estuarine and marine organisms using the
TGAI is conditionally required for the wood preservative uses of this
chemical.  Several studies on marine/estuarine invertebrates were found
in the Agency’s files (Table 5).

Table 5

Test and Organism	Results	Toxicity Category	Comments	Reference

Estuarine Invertebrate Flow-through Acute Toxicity: Eastern Oyster 
(Crassostrea virginica)	 96-hour EC50 = 73 ug a.i./l 

NOEC = 3.2 ug a.i./l	Very highly toxic	Supplemental

No raw data was included	Dionne, E. 1989

MRID# -  411813-03

Estuarine Acute Flow-through Toxicity Study   Sheepshead Minnow
(Cyprinodon   variegatus) 	 96-hour LC50 = 57 ug a.i./l

NOEC = 20 ug a.i./l	Very highly toxic	Core	Sousa, J.V.  1989

MRID# - 411813-01

Estuarine Acute flow-through Toxicity Study Sheepshead Minnow
(Cyprinodon variegates)	96-hour LC50 = 146 ppb a.i.

NOEC = 84 ppb a.i.	Very highly toxic	Core	Durprenant, D.C. 1987

MRID# - 406413-07

Estuarine Acute Toxicity to Mysid Shrimp 

Flow-through

(Mysidopsis bahia) 	96-hour LC50 = 51 ug a.i./l

NOEC = 33 ug a.i./l	Very highly toxic	Core	Hoberg, J.R.  1989

MRID# - 411813-02

Estuarine Acute Toxicity to Mysid Shrimp

Flow-through

(Mysidopsis bahia)	96-hour LC50 = 0.12 ppm a.i.

NOEC = 0.031 ppm a.i.	Highly toxic	Supplemental 

	Surprenant, D.C. 1987

MRID# - 

406413-08

    

As shown in Table 5 this chemical is very highly toxic to mysid shrimp,
sheepshead minnow and eastern oyster.  The sheepshead minnow studies and
one of the mysid shrimp studies were core.  The other two studies (mysid
shrimp and eastern oyster) were supplemental.  

Toxicity to Plants

Plant testing is required for the registered uses of this chemical. 
Seedling emergence–dose response using rice (Oryza sativa) (850.4225)
and Aquatic plant growth (algal and aquatic plant toxicity) – Tier II
(850.4400/850.5400).  No studies were submitted for determining toxicity
to plant species.

 

III.	 Risk Assessment and Characterization

Exposure and Risk to Nontarget Terrestrial Animals and Aquatic Organisms

Risk characterization integrates the results of the exposure and
ecotoxicity data to evaluate the likelihood of adverse ecological
effects.  The means of this integration is called the quotient method. 
Risk quotients (RQs) are calculated by dividing exposure estimates by
acute and chronic ecotoxicity values (RQ =   EXPOSURE/TOXICITY). 

 

RQs are then compared to OPP's levels of concern (LOCs).  These LOCs are
used by OPP to analyze potential risk to nontarget organisms and the
need to consider regulatory action.  The criteria indicate that a
pesticide used as directed has the potential to cause adverse effects on
nontarget organisms.  LOCs currently address the following risk
presumption categories: (1) acute -- potential for acute risk to
non-target organisms which may warrant regulatory action in addition to
restricted use classification, (2) acute restricted use -- the potential
for acute risk to non-target organisms, but may be mitigated through
restricted use classification, (3) acute endangered species - endangered
species may be adversely affected by use, (4) chronic risk - the
potential for chronic risk may warrant regulatory action, endangered
species may potentially be affected through chronic exposure, (5)
non-endangered plant risk – potential for effects in non-target
plants, and (6) endangered plant risk – potential for effects in
endangered plants.   Currently, the Agency does not perform assessments
for chronic risk to plants, acute or chronic risks to nontarget insects,
or chronic risk from granular/bait formulations to birds or mammals.

The ecotoxicity test values (measurement endpoints) used in the acute
and chronic risk quotients are derived from required studies.  Examples
of ecotoxicity values derived from short-term laboratory studies that
assess acute effects are: (1) LC50 (fish and birds), (2) LD50 (birds and
mammals), (3) EC50 (aquatic plants and aquatic invertebrates) and (4)
EC25 (terrestrial plants).  Examples of toxicity test effect levels
derived from the results of long-term laboratory studies that assess
chronic effects are: (1) LOAEC (birds, fish, and aquatic invertebrates),
and (2) NOAEC (birds, fish and aquatic invertebrates). For birds and
mammals, the NOAEC generally is used as the ecotoxicity test value in
assessing chronic effects, although other values may be used when
justified. However, the NOAEC is used if the measurement endpoint is
production of offspring or survival.  Risk presumptions and the
corresponding RQs and LOCs are tabulated below.

Table 14. Risk Presumption Categories

Risk Presumption for Terrestrial Animals	

LOC

  Acute: Potential for acute risk for all non-target organisms	

>0.5

  Acute Restricted Use: Potential for acute risk for all non-target
organisms, but may be mitigated through restricted use classification	

>0.2

  Acute Endangered Species: endangered species may be adversely affected
by use	

>0.1

  Chronic Risk: potential for chronic risk may warrant regulatory action

>1

Risk Presumption for Aquatic Organisms	

LOC

  Acute: Potential for acute risk for all non-target organisms	

>0.5

  Acute Restricted Use: Potential for acute risk for all non-target
organisms, but may be mitigated through restricted use classification	

>0.1

  Acute Endangered Species: endangered species may be adversely affected
by use	

>0.05

  Chronic Risk: potential for chronic risk may warrant regulatory action

>1

Risk Presumption for Terrestrial and Aquatic Plants	

LOC

  Potential for risk for all non-endangered and endangered plants   	

>1

A.	Environmental Fate Assessment Summary (excerpted from the
Environmental Fate Science Chapter of this RED document)

	The Agency has reviewed various environmental fate studies and reports
submitted for BNS.  The data indicate that BNS is likely to degrade
rapidly through hydrolysis and photodegradation after being introduced
into the environment. BNS is not likely to bioaccumulate in fish.  BNS
was slightly mobile to moderately mobile in soil.  It is not expected to
contaminate surface and ground water due to rapid degradation by
hydrolysis and photolysis.  Further information on the environmental
fate of BNS may be found in the Environmental Fate Chapter of this RED
document.

B.	Environmental Exposure and Ecological Risk Assessment

Freshwater and estuarine/marine aquatic organisms, and plants could
potentially be exposed to BNS discharged into the aquatic environment. 
The Agency conducted modeling in 2007 to estimate the exposure and
environment risk resulting from such discharges of BNS from the
once-through cooling tower use.

Tier I 2005 Probabilistic Dilution Modeling for once-through cooling
tower use

This model presents an environmental exposure assessment for releases of
bromonitrostyrene (BNS) used for control of mollusks and bacterial,
algal, and fungal slimes in once-through cooling water systems.  EPA
used the Probabilistic Distribution Model (version 4) to estimate the
number and percentage of days per year that BNS concentrations exceed
ecotoxicity benchmarks of concern.  Analyses were performed for six BNS
treatment scenarios derived from product label information.  The
approach used for this assessment is based on the methodology EPA
developed in support of Ecological Hazard and Environmental Risk
Assessment Chapter for Alkyl Dimethyl Benzyl Ammonium Chloride (ADBAC)
(Petrie and Montague, 2006).  Components of the methodology described in
this section include the probabilistic distribution model (PDM), BNS
application rates, environmental exposure concentrations of concern
(COCs), model facilities and flow data, and modeling scenarios.

PDM is a screening-level exposure assessment tool developed by EPA to
model chemical releases from point sources to flowing surface waters. 
For this analysis, the Agency used the PDM component within EPA’s
Exposure and Fate Assessment Screening Tool Version 2.0 (E-FAST2).  

PDM uses detailed U.S. Geological Survey (USGS) stream flow data and
facility-specific data from National Pollutant Discharge Elimination
System (NPDES) permits to model chemical releases from actual
facilities.  For a modeling period of a given number of days, PDM
calculates probability distribution of the chemical concentration in the
receiving stream, and then estimates the number of days during which the
in-stream chemical concentration is expected to exceed a COC.  PDM
counts a day as having an exceedence of a COC if the COC is exceeded for
any part of a 24-hour day.  As a screening-level model, PDM outputs do
not include the duration, location, or aerial extent of exceedences.

Inputs to PDM include facility NPDES number, pretreatment release (i.e.,
loading rate), post-treatment release, number of release days, and COCs.
 

EPA developed six modeling scenarios by combining assumptions about the
treatment type (i.e., target organism, initial vs. maintenance
treatment), application dose, and application frequency.  The six
scenarios are shown in Table 6.  Scenarios 1 and 2 are for initial and
maintenance control, respectively, of mollusks based on the maximum
label application rate (84 ppm).  Scenario 2 is intended to simulate
maintenance treatment for four hours every other day.  Because PDM
cannot be run for alternating days, Scenario 2 includes treatment for
two hours every day.  

Scenarios 3 through 6 are for control of bacterial, algal, and fungal
slimes using the continuous method (Scenarios 3 and 4) and intermittent
method (Scenarios 5 and 6).  The initial treatment scenarios (i.e.,
Scenarios 3 and 5) include the maximum label application rate, 36 ppm. 
The maintenance treatment scenarios (i.e., Scenarios 4 and 6) use the
midpoint (i.e., 16 ppm) of the range of application rates specified on
the label (i.e., 4 to 36 ppm).

The number of release days assumed for all scenarios was 250.  This
approach assumes that BNS is not applied on weekends and holidays.  

PDM was run once for each combination of facility and scenario.  The
numbers of days exceeding each COC were copied electronically from the
PDM output files into Microsoft ® Excel workbooks where averages and
standard deviations were calculated for each scenario.  In addition, we
calculated the percent of days per year above COCs.  Because the number
of release days per year was 250 for all scenarios, the highest possible
percent of days per year above COCs was 68 percent.  We also calculated
the percent of days during the release period above COCs (maximum 100
percent).  Standard deviations also were calculated for all average
percent of day’s calculations.

Table 6

Modeling Scenarios for Bromonitrostyrene 

Treatment in Once-through Cooling Water Systems

Scenario Number	Target Organisms	Initial/

Maintenance Treatment	Continuous/

Intermittent Method	Application Dose (ppm)	Application Frequency	Release
Days per Year

1	Mollusks	Initial	Intermittent	84 ppm	4 hrs/day	250

2	Mollusks	Maintenance	Intermittent	84 ppm	2 hrs/day	250

3	BFAa	Initial	Continuous	36 ppm	24 hrs/day	250

4	BFA	Maintenance	Continuous	16 ppm	24 hrs/day	250

5	BFA	Initial 	Intermittent	36 ppm	15 min /day	250

6	BFA	Maintenance	Intermittent	16 ppm	15 min/day	250

a BFA = Bacteria, fungi, and algae

Table 7 - Table of COC's

Taxa	LC50/EC50/NOEC

Eastern oyster NOEC	3.2 ppb

Freshwater fish – Bluegill LC50	17 ppb

Freshwater fish – Fathead minnow  LOEC	20 ppb

Freshwater invertebrate – 

Daphnia EC50	24 ppb

Freshwater fish – 

Rainbow  LC50	27 ppb

Mysid shrimp - NOEC	33 ppb

Marine fish – Sheepshead minnow LC50	57 ppb

Marine invertebrate – Mysid shrimp LC50	120 ppb

Marine fish - Sheepshead minnow LC50	146 ppb

Green algae	No data

 

Results for Scenarios 1 through 6 are presented in Tables 4 through 9,
respectively.  Each table shows the average numbers of days when
downstream concentrations of BNS were predicted to exceed each of the
nine COCs.  The average numbers of days were calculated from the
modeling results for the 30 individual facilities.  Because the numbers
of days with 

exceedences varied among the facilities, standard deviations are
presented with each of the averages.  

Tables 4 through 9 also present the averages and standard deviations of
the percentage of days per year and the percentage of the 250 release
days with exceedences of the COCs.  Figure 1 compares the percentages of
release days with exceedences for the six scenarios.  

All six treatment scenarios resulted in exceedence of the lowest COC
(3.2 µg/L) on at least 53 percent of the days when BNS is applied. 
Scenario 3, in which BNS is added continuously for initial control of
bacterial, algal, and fungal slimes, resulted in the highest number of
exceedences.  In particular, the average percentage of release day with
downstream BNS concentrations above COCs with Scenario 3 ranged from 73
percent for the highest COC (146 µg/L) to 99 percent for the lowest
COC.  The second highest number of exceedences occurred with the
continuous maintenance treatment scenario for bacterial, algal, and
fungal slimes (i.e., Scenario 4).  

As shown in Figure 1 the initial control scenarios (i.e., Scenarios 1,
3, and 5) resulted in more exceedences of the COC than the associated
maintenance scenarios (i.e., Scenarios 2, 4, and 6, respectively).  This
reason for this result is that the maintenance scenarios included lower
BNS treatment doses or lower daily treatment durations or frequencies
than the corresponding initial control scenarios.

Table 8

Number and percent of Days with Downstream Bromonitrostyrene
Concentrations Exceeding COCs – Scenario 1

COC

(µg/L)	Number of Days With Exceedences	Percent of Days with Exceedences
per Year	Percent of Release Days with Exceedences

	Average Days COC Exceeded	Standard Deviation	Average Days COC Exceeded
Standard Deviation	Average Days COC Exceeded	Standard Deviation

3.2	230	47	63%	13%	92%	19%

17	203	76	56%	21%	81%	30%

20	199	80	54%	22%	79%	32%

24	194	84	53%	23%	78%	33%

27	192	86	53%	24%	77%	34%

33	188	89	51%	24%	75%	36%

57	177	92	49%	25%	71%	37%

120	159	94	43%	26%	63%	38%

146	153	94	42%	26%	61%	37%

Scenario 1: Initial treatment of mollusks with 84 ppm 4, hrs/day for 250
days

Table 9

Number and percent of Days with Downstream Bromonitrostyrene
Concentrations Exceeding COCs – Scenario 2

COC

(µg/L)	Number of Days With Exceedences	Percent of Days with Exceedences
per Year	Percent of Release Days with Exceedences

	Average Days COC Exceeded	Standard Deviation	Average Days COC Exceeded
Standard Deviation	Average Days COC Exceeded	Standard Deviation

3.2	221	61	60%	17%	88%	24%

17	187	89	51%	24%	75%	36%

20	184	90	50%	25%	74%	36%

24	181	91	49%	25%	72%	37%

27	178	92	49%	25%	71%	37%

33	174	93	48%	26%	69%	37%

57	161	94	44%	26%	64%	38%

120	137	93	38%	25%	55%	37%

146	130	92	36%	25%	52%	37%

Scenario 2: Maintenance treatment of mollusks with 84 ppm, 2 hrs/day for
250 days

Table 10

Number and percent of Days with Downstream Bromonitrostyrene
Concentrations Exceeding COCs – Scenario 3

COC

(µg/L)	Number of Days With Exceedences	Percent of Days with Exceedences
per Year	Percent of Release Days with Exceedences

	Average Days COC Exceeded	Standard Deviation	Average Days COC Exceeded
Standard Deviation	Average Days COC Exceeded	Standard Deviation

3.2	241	27	66%	7%	96%	11%

17	224	60	61%	16%	90%	24%

20	222	62	61%	17%	89%	25%

24	219	65	60%	18%	88%	26%

27	217	66	60%	18%	87%	27%

33	214	69	59%	19%	86%	27%

57	202	80	55%	22%	81%	32%

120	187	89	51%	24%	75%	36%

146	183	90	50%	25%	73%	36%

Scenario 3: Initial Treatment of Bacteria, fungi, and algae with 36 ppm,
continuously for 250 days

Table 11

Number and percent of Days with Downstream Bromonitrostyrene
Concentrations Exceeding COCs – Scenario 4

COC

(µg/L)	Number of Days With Exceedences	Percent of Days with Exceedences
per Year	Percent of Release Days with Exceedences

	Average Days COC Exceeded	Standard Deviation	Average Days COC Exceeded
Standard Deviation	Average Days COC Exceeded	Standard Deviation

3.2	232	44	64%	12%	93%	18%

17	206	73	57%	20%	83%	29%

20	202	76	55%	21%	81%	31%

24	198	81	54%	22%	79%	32%

27	195	83	53%	23%	78%	33%

33	190	88	52%	24%	76%	35%

57	180	92	49%	25%	72%	37%

120	163	94	45%	26%	65%	38%

146	157	94	43%	26%	63%	38%

Scenario 4: Maintenance Treatment of Bacteria, fungi, and algae with 16
ppm, continuously for 250 days

Table 12

Number and percent of Days with Downstream Bromonitrostyrene
Concentrations Exceeding COCs – Scenario 5

COC

(µg/L)	Number of Days With Exceedences	Percent of Days with Exceedences
per Year	Percent of Release Days with Exceedences

	Average Days COC Exceeded	Standard Deviation	Average Days COC Exceeded
Standard Deviation	Average Days COC Exceeded	Standard Deviation

3.2	159	94	43%	26%	63%	38%

17	101	85	28%	23%	40%	34%

20	95	83	26%	23%	38%	33%

24	88	81	24%	22%	35%	32%

27	84	79	23%	22%	33%	32%

33	76	76	21%	21%	30%	30%

57	55	66	15%	18%	22%	26%

120	29	38	8%	11%	11%	15%

146	23	31	6%	9%	9%	13%

Scenario 5: Initial treatment of bacteria, fungi, and algae with 36 ppm,
15 minutes/day for 250 days

Table 13

Number and percent of Days with Downstream Bromonitrostyrene
Concentrations Exceeding COCs – Scenario 6

COC

(µg/L)	Number of Days With Exceedences	Percent of Days with Exceedences
per Year	Percent of Release Days with Exceedences

	Average Days COC Exceeded	Standard Deviation	Average Days COC Exceeded
Standard Deviation	Average Days COC Exceeded	Standard Deviation

3.2	133	92	36%	25%	53%	37%

17	70	73	19%	20%	28%	29%

20	64	71	18%	19%	26%	28%

24	57	67	16%	18%	23%	27%

27	53	64	15%	18%	21%	26%

33	46	59	12%	16%	18%	24%

57	26	36	7%	10%	11%	14%

120	10	15	3%	4%	4%	6%

146	8	12	2%	3%	3%	5%

Scenario 6: Maintenance treatment of bacteria, fungi, and algae with 16
ppm, 15 minutes/day for 250 days

Figure 1:  Average Percent of Release Days with Downstream 

Bromonitrostyrene Concentration Above COCs

Conclusions:

Once-through Cooling Tower Use

Based on the scenarios included in this analysis, the intermittent
treatment method for bacterial, algal, and fungal slimes resulted in
fewer COC exceedences than the continuous treatment method.  Scenarios 5
and 6 simulate the intermittent application method for control of
bacterial, algal, and fungal slimes.  These scenarios use the same
treatment dosages (i.e., 36 ppm for initial control and 16 ppm for
maintenance) as Scenarios 3 and 5, but the treatment duration is 15
minutes per day instead of 24 hours per day.  Tables 6 through 9 and
Figure 1 show that Scenarios 5 and 6 resulted in the fewest exceedences.
 For example, with initial control using the intermittent treatment
method (i.e., Scenario 5) the highest COC (146 µg/L) was exceeded 63
percent of the 250 release days on average, and the lowest COC (3.2
µg/L) was exceeded on nine percent of the 250 release days on average. 

Variables such as stream flow rate and BNS dissipation, degradation, and
1/2 life were not considered in this Tier I model but should be
considered in higher tier modeling.  Field monitoring is suggested in
the absence of higher Tier modeling.  Risk mitigation recommendations
should be based on dosing method and application rate instead of
facility size, however, risk mitigation is not recommended at this time.

Maximum Expected Environmental Concentrations:	  The treatment scenario
that resulted in the maximum expected environmental concentrations was
#3 (continuous treatment using 36 ppm of BNS 24 hours/day 250 days a
year).  The number of days that exceeded the LOCs ranged from 183 to 241
(Table 10) for all the aquatic species.  

	

Maximum Ecotoxicity Values:  Eastern oyster has an NOEC of 3.2 ppb;
freshwater fish LC50s ranged from 17 to 27 ppb; freshwater invertebrate
EC50 was 24 ppb; sheepshead minnow LC50 was 57 ppb; mysid shrimp LC50
was 120 ppb; and sheepshead minnow LC50 was 146 ppb. Freshwater fish
(fathead minnow) chronic LOEC was 20 ppb.       

Acute Freshwater Fish LOC’s:  Bluegill sunfish ranged from 70 to 224
days exceedence (See Tables 8, 9, 10, 11, 12, and 13).  Rainbow trout
ranged from 53 to 217 days exceedence (See Tables 8, 9, 10, 11, 12, and
13).  All of the modeled scenarios exceeded the LOC’s       

Acute Freshwater Aquatic Invertebrate LOC’s:  Daphnid ranged from 53
to 219 days exceedence (See Tables 8, 9, 10, 11, 12, and 13).  All of
the modeled scenarios exceeded the LOC’s. 

Acute Aquatic Estuarine/Marine Species:  The Eastern oyster ranged from
133 to 241 days exceedence (See Tables 8, 9, 10, 11, 12, and 13).  The
mysid shrimp ranged from 46 to 214 days exceedence (See Tables 8, 9, 10,
11, 12, and 13).  The Sheepshead minnow ranged from 8 to 202 days
exceedence (See Tables 8, 9, 10, 11, 12, and 13).  All the modeled
scenarios exceeded the LOC’s.

	

Chronic Aquatic Toxicity Studies:  Chronic fish study using the Fathead
minnow ranged from 64 to 224 days exceedence (See Table 8, 9, 10, 11,
12, and 13).  All of the modeled scenarios exceeded the LOC’s.

 

Plant Toxicity Studies:  No studies were available.  

Avian and Mammalian Species:  The avian testing demonstrated no
toxicity.  No risk to avian species is expected from the use of BNS.    

C.      Endangered Species Considerations

Section 7 of the Endangered Species Act, 16 U.S.C. Section 1536(a)(2),
requires all federal agencies to consult with the National Marine
Fisheries Service (NMFS) for marine and andronomus listed species, or
the United States Fish and Wildlife Services (FWS) for listed wildlife
and freshwater organisms, if they are proposing an "action" that may
affect listed species or their designated habitat.  Each federal agency
is required under the Act to insure that any action they authorize,
fund, or carry out is not likely to jeopardize the continued existence
of a listed species or result in the destruction or adverse modification
of designated critical habitat.  To jeopardize the continued existence
of a listed species means "to engage in an action that reasonably would
be expected, directly or indirectly, to reduce appreciably the
likelihood of both the survival and recovery of a listed species in the
wild by reducing the reproduction, numbers, or distribution of the
species." 50 C.F.R. ( 402.02.

To facilitate compliance with the requirements of the Endangered Species
Act subsection (a)(2) the Environmental Protection Agency, Office of
Pesticide Programs has established procedures to evaluate whether a
proposed registration action may directly or indirectly reduce
appreciably the likelihood of both the survival and recovery of a listed
species in the wild by reducing the reproduction, numbers, or
distribution of any listed species (U.S. EPA 2004).  After the Agency(s
screening-level risk assessment is performed, if any of the Agency(s
Listed Species LOC Criteria are exceeded for either direct or indirect
effects, a determination is made to identify if any listed or candidate
species may co-occur in the area of the proposed pesticide use.  If
determined that listed or candidate species may be present in the
proposed use areas, further biological assessment is undertaken.  The
extent to which listed species may be at risk then determines the need
for the development of a more comprehensive consultation package as
required by the Endangered Species Act.

For certain use categories, the Agency assumes there will be minimal
environmental exposure, and only a minimal toxicity data set is required
(Overview of the Ecological Risk Assessment Process in the Office of
Pesticide Programs U.S. Environmental Protection Agency - Endangered and
Threatened Species Effects Determinations, 1/23/04, Appendix A, Section
IIB, pg.81).  Chemicals in these categories therefore do not undergo a
full screening-level risk assessment.  Materials preservative uses (in
inks, dyes, textiles, adhesives, caulks, sealants, paper, paints,
polymers) are considered to fall under a No Effect determination (NE)
because:  

The amount that will actually reach the environment is very small based
on usage data and use patterns (no homeowner/residential use for
bathrooms) and containment methods (retaining ponds, recirculation, low
residual upon release).  

Breakdown in the environment and via sewage treatment is rapid and well
documented in the literature (See Environmental Fate Chapter for more
detail).  The agency requires the following label statement:  "Do not
discharge effluent containing this product into lakes, streams, ponds,
estuaries, oceans, or other waters unless in accordance with the
requirements of a National Pollutant Discharge Elimination System
(NPDES) permit and the permitting authorities are notified in writing
prior to discharge.  Do not discharge effluent containing this product
to sewer systems without previously notifying the local sewage treatment
plant authority.  For guidance contact your State Water Board or
Regional Office of the EPA."  There was no information in the Sewage
Treatability Database on BNS.

	BNS uses that have potential for environmental exposure via
down-the-drain or runoff to surface waters include industrial processes
and water system wastes.  Industrial disposal water, sewage systems, and
once-through cooling tower water uses may generate waste water residues
that may reach the environment.  The once-thru cooling tower use is
considered to be representative of a worst-case example (highest
potential for impacting the environment), and therefore, this site was
modeled.  

The “best case” once-through cooling tower scenario using 1/2 the
maximum recommended label dosage intermittently applied in a low water
flow resulted in LOC exceedances for all aquatic organisms used in the
model, including freshwater fish, green alga, freshwater invertebrates,
and marine invertebrates.  The agency is not aware of any endangered or
threatened green algae.  Because BNS is rapidly degraded through
hydrolysis and photodegradation, impacts to aquatic organisms may be
less than modeled.  The once-through cooling tower model does not
account for degradation and therefore, further assessment is required
prior to making an agency endangered species determination.  

		This preliminary analysis indicates that there is a potential for BNS
industrial water waste discharges to overlap with listed species and
that a more refined assessment is warranted, to include direct, indirect
and habitat effects.  The more refined assessment should involve clear
delineation of the action area associated with proposed use of BNS and
best available information on the temporal and spatial co-location of
listed species with respect to the action area.  This analysis has not
been conducted for this assessment.  An endangered species effect
determination will not be made at this time.

IV.	Confirmatory Data Required

1.   Non-target Plant Phytotoxicity Studies are Required:  850.4225
(seedling 	                                                             
                                                                      
emergence using rice), 850.4400 (Lemna gibba), 850.5400 (Algal toxicity,
3 species:  blue-green cyanobacteria  Anabeana flos-aquae, freshwater
diatom Navicula pelliculosa, marine diatom Skeletonema costatum).

           2.  Monitoring and/or Tier II modeling of once-through
cooling tower effluents to                                              
                                                                        
                                                                        
                                                                        
                                                                        
                                                                        
      establish EEC's for risk assessment, and to evaluate degradation
and decline of BNS (and major transformation products) residues in
effluent and receiving surface waters.

                                                                        
         

V.  Label Hazard Statements for Terrestrial and Aquatic Organisms and
Use                              Recommendations

BNS labels must state:  

"This pesticide is toxic to fish, aquatic invertebrates, oysters, and
shrimp".

"Do not discharge effluent containing this product into lakes, streams,
ponds, estuaries, oceans, or other waters unless in accordance with the
requirements of a National Pollutant Discharge Elimination System
(NPDES) permit and the permitting authorities are notified in writing
prior to discharge.  Do not discharge effluent containing this product
to sewer systems without previously notifying the local sewage treatment
plant authority.  For guidance contact your State Water Board or
Regional Office of the EPA."



REFERENCES

Petrie, R. and Montague, K. (2006) Ecological Hazard and Environmental
Risk Assessment Chapter, Alkyl Dimethyl Benzyl Ammonium Chloride
(ADBAC), PC Code: 069105, Case No: 0350, U.S. Environmental Protection
Agency, Office of Pesticide Programs, Antimicrobial division, August 2,
2006. 

MRID# 406413-03:  Grimes, J. and Jaber, M. (1987) GIV2-0820:  An acute
oral toxicity study with the mallard duck (Anas platyrhynchos). 
Wildlife International.

 

MRID# 406413-04:  Grimes, J. and Jaber, M. (1987) GIV2-0820:  A dietary
LC50 study with the mallard.  Wildlife International. 

MRID# 406413-05:  Grimes, J. and jabber, M. (1987) GIV2-0820:  A dietary
LC50 study with the bobwhite.  Wildlife International. 

MRID# 406413-08:  Surprenant, D.C. (1987) Acute Toxicity of GIV2-0820 to
Mysid Shrimp (Mysidopsis bahia) Under flow-through conditions. 
Springborn Laboratories, Inc. 

MRID# 411648-01:  McNamara, P.C. (1989) Acute toxicity of GIV2-0820 to
daphnids (Daphnia magna) during a 48-hour flow-through acute exposure. 
Springborn Life Sciences, Inc.  

MRID# 411648-02:  Sousa, J. (1989) Acute Toxicity of GIV2-0820 to
rainbow trout (Salmo gairdneri) under flow-through conditions. 
Springborn Life Sciences, Inc. 

MRID# 411813-01:  Sousa, J.V. (1989) Acute toxicity of GIV2-0820 to
sheepshead minnow (Cyprinodon variegates) under flow-through conditions.
 Springborn Life Sciences, Inc.

MRID# 411813-02:  Hoberg, J.R. (1989) Acute toxicity of GIV2-0820 to
mysid shrimp(Mysidopsis bahia) under flow-through conditions. 
Springborn Life Sciences, Inc.

MRID# 411813-03:  Dionne, E. (1989) Acute toxicity of GIV2-0820 to
eastern oysters under flow-through conditions.  Springborn Life
Sciences, Inc. 

MRID# 416035-05:  Bowman, J. and Stuerman, L. (1990) Acute flow-through
toxicity of GIV2-0820 to bluegill (Lepomis macrochirus).  ABC
Laboratories, Inc. 

MRID# 423997-01:  Cohle, P. and Stratton, J. (1992) Early Life-Stage
Toxicity of BNS to Fathead Minnows in a flow-through system ABC
Laboratories.  



APPENDIX

PDM4 Modeling Results for Bromonitrostyrene

in Once-Through Industrial Water Systems