UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON. D.C. 20460 

March 9. 2016 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

PC Code 112701 ; DP Barcode 429375 

MEMORANDUM 

SUBJECT: Problem Formulation for Registration Review of Brodifacoum 

FROM: 

1 r-Brian 

Jose Melendez, 

Montague

Chemist 

, Fishery Biologist (j}.W 

K 

tv. 

~ 

V ~,)_....__ ~ . 2f 

/f Environmental Risk Branch V 

REVIEWED 

BY: 

Environmental Fate and Effects Division (7507P) 

Justin Housenger, Biologist 

Gabriel Rothman, Environmental Scientist 

Environmental Risk Branch V 

Environmental Fate and Effects Division (7507P) 

THROUGH: 

Env

Mah 

ironm

T. Shamim

ental Risk 

, Ph.

Branch 

D., Branch 

V 

Chief 

fl 

'~ 1 

Environmental Fate and Effects Division (7507P) 

TO: Ricardo Jones, Chemical Reviev.1 Manager 

Melissa Grable, Team Leader 

Neil Anderson, Branch Chief 

Risk Management and Implementation Branch I 

Pesticide Re-Evaluation Division (7508P) 

Please, find attached the Preliminary Problem Formulation for the Ecological Risk Assessment 

and Drinking Water Exposure Assessment for Registration Review to be conducted for 

Brodifacoum. 
2

Problem Formulation for the Environmental Fate, 

Ecological Risk, Endangered Species, and Drinking 

Water Exposure Assessments in Support of the 

Registration Review for Brodifacoum

Brodifacoum

CAS No. 56073-10-0

PC Code 112701

Prepared by:

Brian Montague, Fishery Biologist 

José Meléndez, Chemist

U.S. Environmental Protection Agency

Office of Pesticide Programs

Environmental Fate and Effects Division

Environmental Risk Branch V

1200 Pennsylvania Ave., NW

Mail Code 7507P

Washington, DC 20460

Reviewed by:

Justin Housenger, Biologist

Gabriel Rothman, Environmental Scientist

Mah Shamim, Ph.D., Chief ERB5
3

Contents

1. Executive Summary.................................................................................................................... 4

2. Introduction................................................................................................................................. 5

3. Use Characterization................................................................................................................... 6

4. Conclusions from Previous Risk Assessments........................................................................... 8

4.1 Ecological Risk Assessments........................................................................................... 8

4.2 Drinking Water Exposure Assessments........................................................................... 9

4.3 Clean Water Act Programs............................................................................................... 9

5. Environmental Fate and Transport............................................................................................ 10

5.1 Transformation Products................................................................................................ 12

6. Receptors................................................................................................................................... 13

6.1 Toxicity Summary.......................................................................................................... 13

6.1.2 Effects to Terrestrial Organisms................................................................................. 14

6.2 Secondary Poisoning Potential....................................................................................... 15

6.3 Ecological Incidents....................................................................................................... 16

7. Exposure Pathways of Concern ................................................................................................ 17

7.1 Aquatic Exposure ........................................................................................................... 17

7.2 Terrestrial Exposure ....................................................................................................... 18

8. Analysis Plan ............................................................................................................................ 18

8.1 Stressors of Concern....................................................................................................... 18

8.1.1 Ecological Risk Assessment ................................................................................... 18

8.1.2 Drinking Water ....................................................................................................... 19

8.2 Measures of Exposure .................................................................................................... 19

8.2.1 Estimating Primary Exposure for Terrestrial Organisms........................................ 19

8.2.2 Accumulation through Multiple Feedings on Bait.................................................. 20

8.2.3 Estimating Secondary Terrestrial Exposure............................................................ 21

8.2.4 Estimating Aquatic Exposure ................................................................................. 22

8.2.5 Available Water Monitoring Data .......................................................................... 22

8.3 Measures of Effect ......................................................................................................... 23

9. Endangered Species Assessments............................................................................................. 23

10. Endocrine Disruptor Screening Program................................................................................ 24

11. Preliminary Identification of Data Gaps................................................................................. 24

11.1 Environmental Fate..................................................................................................... 24

11.2 Effects......................................................................................................................... 25

12. References............................................................................................................................... 30

Appendix A. Brodifacoum Bibliography...................................................................................... 32

Appendix B. EPI Suite v.4.1 Output File for Brodifacoum.......................................................... 45

Appendix C. SIPS Model Input/Output........................................................................................ 57

Appendix D. Pending and Active Registrations For 112701 / 56073-10-0 / Brodifacoum.......... 59
4

1. Executive Summary

The Environmental Fate and Effects Division (EFED) has completed the preliminary 

problem formulation for the ecological risk, environmental fate, endangered species, and drinking 

water assessments to be conducted as part of the registration review of brodifacoum. Brodifacoum 

is a coumarin rodenticide for control of Norway rats, roof rats and house mice. The primary route 

of transport for brodifacoum is through consumption of bait product within the bait box, 

accumulation of the ingested chemical within the bodies of those organisms, followed by their 

subsequent movement to offsite locations. Brodifacoum may require a period of days before it 

kills birds, mammals, or other organisms which feed on the bait. These poisoned animals may in 

turn become sources of exposure to brodifacoum if consumed by predators, scavengers, or 

insectivores or if poisoned animals are fed by predators to their own young. These exposure 

pathways will be the primary focus of the Brodifacoum Preliminary Risk Assessment (PRA). 

The problem formulation describes the methods planned to be used during the completion 

of drinking water and ecological risk assessments in support of registration review and provides 

an overview of the environmental fate, ecological effects, and potential risks associated with the 

use of brodifacoum as well as uncertainties unique to risk assessment of brodifacoum. This 

document also identifies additional studies that would be beneficial to the conduct of an ecological 

risk assessment. Key uncertainties and related data requirements for brodifacoum are listed below:

Environmental Fate Uncertainties and Data Requirements

Certain environmental fate studies were submitted and considered suitable for a deterministic risk 

assessment. Quantitative structure activity relationships (QSARs) (e.g., EPI Suite v.4.1) were used 

to determine the KOC and BCF for this chemical. The KOW reported by the registrant was also 

based on QSAR because it was too high to be measured experimentally. Data have not been 

submitted to fulfill some guidelines; however, these data are not necessary for risk assessment at 

this time.

It appears that there is a low potential for residues of brodifacoum to leach (or be extracted) from 

the bait stations, if exposed to normal rainwater or runoff, and to reach surface water. There is one 

possible exception: the use of the chemical in sewers systems. The concerns for sewer use are that

non-target organisms may visit sewers and/or chunks of bait blocks could be knocked or broken 

off as bait is eaten, discharged with stormwater or sewage overflow, and then consumed by nontarget organisms. For the uses on sewer systems, instructions indicate to thread wire through 

blocks and securely attach to a stationary structure such as the bottom step of a manhole ladder or 

a sewer grate, allowing just enough wire for the block to rest on manhole benching. If benching 

is not present, blocks should be suspended a few inches above the high water mark, thus preventing 

removal by rats or water. EFED recommends confirmation that suitable instructions are included 

in the labels, to limit exposure of brodifacoum to sewer water, or to non-target organisms in sewer 

systems.
5

Ecological Effects Uncertainties and Data Requirements

For the ecological effects, no studies have been submitted to characterize chronic toxicity to avian 

species (i.e., avian reproduction studies) or oral toxicity to a passerine species. An acute contact 

toxicity study with the honey bee is not available for this assessment. There are no studies to 

characterize chronic effects to aquatic organisms or acute effects to aquatic plants. The following 

guideline studies would clarify uncertainties, but only avian studies are requested at this time.

850.2100 Acute Oral Toxicity – Passerine Species

Smaller passerine species may be more sensitive than species previously tested with 

brodifacoum. Currently no data is available to clarify this uncertainty. This study is 

requested.

850.2300: Avian Reproduction Study: Little is known about the effects of low level sublethal dietary levels on reproductive success for non-target avian species. Brodifacoum is 

shown to accumulate in adult tissues and blood of birds who have presumably ingested 

contaminated prey, but not succumbed to these exposure levels. Due to the extreme acute 

toxicity of this chemical to birds a design protocol should be submitted before conduct of 

the studies for determination of test concentrations and methods. This guideline testing is 

requested for one upland game species and one waterfowl species.

2. Introduction

Brodifacoum is a coumarin second generation anticoagulant rodenticide (SGAR), for 

control of Norway rats (Rattus norvegicus), roof rats (Rattus rattus) and house mice (Mus 

musculus). According to the 2004 Comparative Assessment (USEPA 2004b), the anticoagulant 

rodenticides’ mode of action is as follows: “The anticoagulant rodenticides are vitamin-K 

antagonists that disrupt normal blood-clotting mechanisms and induce capillary damage (Pelfrene 

1991). Death results from hemorrhage, and exposed animals may exhibit increasing weakness 

prior to death. Behavior also may be affected (Cox and Smith, 1992).

Second-generation anticoagulants tend to be more acutely toxic than are the firstgeneration anticoagulants, and they are retained longer in body tissues of primary consumers. The 

greater potency and duration of action of long-acting anticoagulant rodenticides is attributed to 

their: (i) greater affinity for vitamin K(1)-2,3-epoxide reductase; (ii) ability to disrupt the vitamin 

K(1)-epoxide cycle at more than one point; (iii) hepatic accumulation; and (iv) unusually long 

biological half-lives due to high lipid solubility and enterohepatic circulation (Watt et al. 2005).

In general, rodents require only one feeding of bait to receive a lethal dose. Because it takes 

several days for the rodent to die, animals may return to feed on the bait, thus acquiring multiple doses

and allowing for higher, more lethal concentrations of the rodenticide to accumulate. Second 

generation anticoagulant rodenticides become concentrated in the animal’s liver, with liver half-lives 

of up to a year. If an animal that consumes a second generation anticoagulant rodenticide is eaten by 

a predator or scavenger, then that animal can become secondarily exposed and affected by the 
6

rodenticide. Because of their long half-lives, these rodenticides have been shown to bioaccumulate in 

non-target wildlife.

EFED evaluated the most recent ecological risk assessments for brodifacoum to update the

toxicity, exposure, and usage information and determine if sufficient data are available or if further 

updates are needed to support registration review. Previous risk assessments are covered in detail 

under Section 4 and include assessments of the risk of brodifacoum use on endangered species, 

Reregistration Eligibility Decision (RED)-Rodenticide Cluster in July 1998 (USEPA, 1998b), 

Special assessment paper Potential Risks of Nine Rodenticides to Birds and Nontarget Mammals: 

a Comparative Approach (USEPA 2004b), and a 2012 endangered species assessment for the 

Alameda whipsnake, salt marsh harvest mouse, and San Joaquin kit fox (USEPA 2012). In 2011 

there was a Scientific Advisory Panel (SAP) and an Agency Notice of Intent to Cancel (NOIC)

Non-Compliant Rodenticides, including brodifacoum.

 

In addition, EFED considered the latest Agency science policies and risk assessment 

methodologies. The structure of brodifacoum, as well as the chemical names and other identifiers 

can be found in the Figure 1 and the chemical identity table (Table 2).

3. Use Characterization

Current uses of brodifacoum have been established consistent with a Risk Mitigation 

Decision (RMD) in 2008 encompassing ten Rodenticides. The RMD primarily includes two 

important provisions that relate to brodifacoum. First, for all second generation anticoagulants 

(the subclass of rodenticides to which brodifacoum belongs), application is restricted to tamper 

resistant bait boxes for all above ground uses. These tamper-resistant bait stations are required 

if the bait placement are within reach of pets, domestic animals, non-target wildlife, or children 

under six years-of-age. Other types of bait stations may be constructed and used in settings, such 

as around livestock production buildings, where exposure to children and non-target wildlife is 

less likely. The second provision, regarding package size restrictions on these second generation 

anticoagulants, prevents the average consumer from purchasing any package size less than 16 

lbs. Prior to the RMD, consumers (particularly homeowners looking for readily accessible rodent 

control options) were able to purchase products containing brodifacoum in small packaging in 

grocery stores, warehouses and many other commercial establishments. It was expected that the 

movement of second generation rodenticides to tamper resistant bait boxes would reduce primary 

exposure of brodifacoum to non-target organisms, but the potential for secondary exposure would 

still exist since brodifacoum is very acutely toxic to birds and mammals and has a long persistence 

in body tissues, making it available to secondary consumers such as predatory mammals and birds.

In agricultural settings, applications should occur in and within 100 feet of agricultural 

buildings and man-made agricultural structures. The applications of brodifacoum are restricted to 

pest control operators (PCOs), except for applications in agricultural sites.

Current Office of Pesticide Programs (OPP) use information lists 22 active end-use 

products as well as 3 products that are pending, and two of which are registered to the U.S. 

Department of Agriculture for Conservation use in eradication of invasive rodent species in 

sensitive habitats. Two registrants produce the technical grade actives, Bell Laboratories (98% ai) 
7

and Syngenta Crop Protection Products (90% ai). See Appendix D for a complete listing of 

registered products and their associated registrants. The products are formulated as solid/bait, 

including pellets/tablets, blocks, granules and solid concentrate. Currently, labeled uses of 

brodifacoum include sites in and around homes, agricultural, industrial and commercial buildings, 

food processing plant premises (nonfood contact), transport facilities, vehicles, ships and boats,

nonagricultural uncultivated areas, ornamental and/or shade trees and woody shrubs and vines, 

refuse/solid waste containers (garbage cans), and sewers. Application methods include bait 

treatment, sewer treatment, and animal burrow treatment. Product labels for brodifacoum

generally do not limit the amount of product or active ingredient that may be applied per unit area, 

the number of applications that can be made per unit time, or the minimum interval between 

applications. Labels state the amount of bait (e.g., number of blocks or mass of bait per placement)

that may be placed in one location, and the linear distance between placements. The linear distance

is 15 to 30 feet. The concentration of brodifacoum in the bait is 0.0025% or 0.005% for its products 

(i.e. 25 or 50 mg a.i./kg bait). The maximum amount of active ingredient per placement, or the 

amount of active ingredient per linear feet, can be calculated for the products. This maximum 

amount allowed is 0.00005 lb a.i./placement.1

 Applications are allowed as needed.

The chemical profile produced by BEAD, located in the docket, lists the use patterns of 

maximum exposures for the current uses of brodifacoum. Since labels are not explicit on the 

application interval, the annual maximum number of applications allowed, or application method, 

EFED will use application scenarios that result in maximum exposure for a given use for the risk 

assessment.

 1 For animal burrow treatment the maximum allowed is 0.00000625 lb a.i./burrow. For burrows, 3-4 oz product are 

placed in each burrow entrance in piles or in cloth or re-sealable plastic bags. An uninterrupted bait supply should 

be kept for at least 15 days or until rodent activity ceases. The maximum rate for broadcast applications is 0.0004 

lb a.i./A.
8

4. Conclusions from Previous Risk Assessments

4.1 Ecological Risk Assessments 

The Agency has conducted multiple ecological risk assessments that serve as a basis for 

this problem formulation, including an assessment of the risks of several rodenticides, which 

included brodifacoum, in the Reregistration Eligibility Decision (RED): Rodenticide Cluster that 

was published in July 1998 (USEPA, 1998b). An assessment of the risks of brodifacoum to 

terrestrial wildlife was also included in the 2004 document Potential Risks of Nine Rodenticides 

to Birds and Nontarget Mammals: a Comparative Approach (USEPA 2004b, MRID 47114602).

In 2012 an endangered species assessment was conducted for the use of brodifacoum and the 

federally threatened Alameda whipsnake (AW, Masticophis lateralis euryxanthus), the federally

endangered salt marsh harvest mouse (SMHM, Reithrodontomys raviventris), and the federally

endangered San Joaquin kit fox (SJKF, Vulpes macrotis mutica) USEPA 2012) and examined in 

depth the potential for exposure of these species and taxa to brodifacoum use in California. In 

June of 2013 the California Department of Pesticide Regulation issued an extensive analysis of 

second generation rodenticide use in California entitled Second Generation Anticoagulant 

Rodenticide Assessment which also provides valuable information on effects of actual use of 

broadifacoum and other similar rodenticide products in that State.

In 2008, EPA released the Risk Mitigation Decision for Ten Rodenticides (RMD) (EPA 

2008, Docket ID EPA-HQ-OPP-2006-0955). Brodifacoum products were included in the list of 

ten rodenticides addressed in the document. The focus of this decision was:

1) To minimize children’s exposure to rodenticide products used in homes by requiring 

that all rodenticide bait products marketed to general and residential consumers be sold 

only with bait stations, with loose bait (e.g., pellets and meal) as a prohibited bait form. 

2) To reduce wildlife exposures and ecological risks, by requiring sale and distribution 

limits intended to prevent general consumers from purchasing residential use bait 

products containing four of the ten rodenticides that pose the greatest risk to wildlife 

(the second generation anticoagulants – brodifacoum, bromadiolone, difenacoum, and 

difethialone). Moreover, bait stations will be required for all outdoor, above-ground 

uses of these second generation anticoagulants.

For brodifacoum and difethialone, certain labels were not brought into compliance with 

these provisions of the RMD. Consequently, these second generation anticoagulant rodenticides, 

along with warfarin and bromethalin, were the subject of a Notice of Intent to Cancel (NOIC) 

hearing. In the case of bromethalin, there were both RMD-compliant and non-compliant labels. 

Additionally, two first generation anticoagulant rodenticides that would serve as the likely 

alternatives with the removal of the chemicals concerned in the NOIC (chlorophacinone and 

diphacinone) were assessed. To support the NOIC, EPA conducted an extensive assessment of 

the potential for primary and secondary effects of the rodenticides under evaluation which updated 

previous risk assessment findings conducted in support of the May 2008 RMD through the 

application of additional effects and exposure data, use of additional exposure modeling, and 
9

quantitative risk assessment techniques. This work was brought before the Science Advisory Panel 

(SAP) in 2011 for review. Meeting materials from the SAP are available under docket number 

EPA-HQ-OPP-2011-0718.

The primary risk issues have been identified for certain terrestrial non-target animals, 

consistent with a rodenticide use. In the 2004 EPA paper by Urban and Erickson the comparative 

assessment stated: “Brodifacoum and difethialone stand out as the two rodenticides posing the 

greatest potential overall risk to birds and non-target mammals, followed by bromadiolone and 

diphacinone.” Also the paper states “Brodifacoum and difethialone pose the greatest potential 

risks to avian predators and scavengers that feed on target or non-target animals poisoned with 

bait.” 

The most recent, comprehensive assessment conducted for brodifacoum is the endangered 

species assessment (ESA), which was issued in March 2012 (USEPA 2012). The major ecological 

conclusions presented in the ESA were as follows:

Table 1. Summary of Risk Concerns Identified for Brodifacoum in Previous ESA

Birds Mammals Terr.

Plants

Terr.

Inverts Fish BCF Aquatic Inverts

Aquatic 

Plants

Groundwater 

Contamination Persistence Degradates of Concern

Yes Yes No1 NA NA Yes2 NA No1 No Yes2 None

Yes = at least one LOC has been exceeded in previous assessments; “No” = LOCs have not been exceeded in previous 

assessments; NA = RQs have not been calculated previously.

1

Effects on terrestrial and aquatic plant communities were judged to be discountable. 2

Although there is no Fish BCF study for brodifacoum, open literature studies suggest that brodifacoum persists in 

liver tissue of terrestrial animals – see Table 9 for references.

4.2 Drinking Water Exposure Assessments

A drinking water assessment has not been previously conducted on brodifacoum. The 

exclusive use of brodifacoum bait outdoors in bait stations, the extremely low concentrations in 

bait, and the hydrophobicity of the compound, reduces potential for extraction (leaching) of 

brodifacoum residues from the bait station, or leaching to subsurfaces or runoff, if exposed to 

rainwater or surface runoff. Surface or groundwater exposure is expected to be negligible. Refer 

to Section 8.1.2 for further details.

4.3 Clean Water Act Programs

Brodifacoum is not identified as a cause of impairment for any water bodies listed as 

impaired under section 303(d) of the Clean Water Act, based on information provided at 

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

No Total Maximum Daily Load (TMDL) criteria have been developed for brodifacoum, based on

information provided at:

http://iaspub.epa.gov/tmdl_waters10/attains_nation.tmdl_pollutant_detail?p_pollutant_group_id

=885&p_pollutant_group_name=PESTICIDES. Aquatic benchmarks have not been established

for brodifacoum (at http://www.epa.gov/pesticide-science-and-assessing-pesticide-risks/aquaticlife-benchmarks-pesticide-registration). Any data submitted or otherwise located as part of the 

registration review process may be used to update aquatic life benchmarks if applicable.
10

5. Environmental Fate and Transport

Table 2 lists various important physicochemical properties of brodifacoum. Table 3 lists 

available environmental fate properties of brodifacoum, from the submitted environmental fate 

and transport studies. The structure of brodifacoum is provided in Figure 1. In this problem 

formulation many of the physical/chemical properties of brodifacoum were obtained using the 

quantitative structure-activity relationship (QSAR) estimation software EPI Suite (USEPA 2011). 

For complete EPI Suite v.4.1 output file see the Appendix B.

Figure 1. Structure of Brodifacoum2

Table 2. Physicochemical Properties of Brodifacoum

Property Value and units MRID or Source

Molecular Weight 523.43 g/mole EPI Suite v.4.1 (USEPA 2011)

Chemical Formula C31H23BrO3 EPI Suite v.4.1 (USEPA 2011)

CAS Name

3-[3-(4′-bromo[1,1′-biphenyl]-4-yl)-1,2,3,4-

tetrahydro-1-naphthalenyl]-4-hydroxy-2H-1-

benzopyran-2-one

Brodifacoum’s data sheet1

IUPAC Name 3-[(1RS,3RS;1RS,3SR)-3-(4′-bromobiphenyl-4-yl)-

1,2,3,4-tetrahydro-1-naphthyl]-4-hydroxycoumarin Brodifacoum’s data sheet1

CAS No. 56073-10-0 41892202

Color/Physical State Cream colored, fine, powdery solid 41892201

Density 1.42 g/cm3 at 250C 41892201

pH 3.8 in a 1% v/v dispersion in water at approx. 200C 41892201

Melting Point 2320C 41892202

Water Solubility

0.0038 mg/L at 200C and pH 5.2;

0.240 mg/L at pH 7.4; 10.0 mg/L at pH 9.3

buffered water and 200C

41892202; only the pH 5.2 

solubility appears in EPI Suite 

4.1’s database (USEPA 2011)

Vapor Pressure

1.11x10-18 mmHg (torr) at 250C

<<10-8 torr at 200C

‘Non-volatile from a field condition’

EPI Suite v.4.1 Estimate 

(USEPA 2011)

41892202

USEPA, 2008a

 2 The structure of the chemical was obtained from the brodifacoum data sheet available at 

http://www.alanwood.net/pesticides/brodifacoum.html (accessed 08/21/2015).
11

Property Value and units MRID or Source

Henry’s Law Constant

2.012 x 10-16 atm-m3/mole at 250C

<<10-8 atm-m3/mole at pH 7.4 and 200C

EPI Suite v.4.1 calculated from 

WS and VP estimate (USEPA 

2011)

41892202

n-Octanol-water 

partition coefficient 

(log KOW)

3.16 x 108 (log KOW = 8.5)

(Estimated based on SARs)

MRID 41892202; solubility too 

low to obtain experimental value

Dissociation Constant

(pKa) 4.44 (Temperature not specified)

EPI Suite 4.1 database (USEPA 

2011) (Tomlin, C. 1997, cited by 

EPI Suite)

Air-water partition 

coefficient (KAW)

KAW = Cair/Cwater = HLC/RT

KAW = 8.23 x 10-15

‘Non-volatile’ (from a water surface)

Calculated Value,

USEPA, 2008a

Cwater+soil/Cair

Cwater+soil/Cair = (1/KAW) (1/r + Kd) =

9.58 x 1018

‘Non-volatile from moist soil’

Assuming Kd ≈ 0.02 x KOC

Calculated value

USEPA, 2008a

n-Octanol-air partition 

coefficient (KOA) Henry's Law Constant

K RT

K

K

K OW

AW

OW

OA = =

KOA = 3.84 x 1022

Calculated value, using EPI

Suite v.4.1’s KOW (USEPA 

2011)

UV/visible light 

absorption Maxima at around 205, 265 and 310 nm. 41892202

1

http://www.alanwood.net/pesticides/brodifacoum.html (accessed 08/21/2015).

It appears that the primary route of dissipation/transport for brodifacoum with the pertinent 

exposure pathways to terrestrial organisms is consumption of bait product and movement of the 

intact chemical within the bodies of the vertebrates or invertebrates that feed on the bait and move 

to offsite locations. Brodifacoum may require a period of days before it kills birds, mammals, or 

other organisms which feed on the bait. These poisoned animals may in turn become sources of 

exposure to brodifacoum if consumed by predators, scavengers, or insectivores or fed by them to 

their own young. Brodifacoum has a high octanol/water partition coefficient (KOW = 3.16x108

) 

(Table 2). Based on it octanol/water partition coefficient, it appears that brodifacoum has the

potential to bioaccumulate/bioconcentrate. Brodifacoum has a very low vapor pressure of 1.11 x 

10-18 mmHg, and its calculated Henry’s Law Constant is low (2.012 x 10-16 atm-m3

/mol). 

Brodifacoum has very little potential to volatilize.

For brodifacoum, the log KOA is 22.5, the log KOW is 8.5, the rate of transformation is 

relatively slow in the environment, and the rate of transformation appears to be relatively slow in 

fish (with an EPIWEB v.4.1 estimated half-life of 351 days) (Table 3); based on this information, 

it appears that brodifacoum has a potential to biomagnify in terrestrial food chains, based on the 

presumption made by Gobas et al. (2003) and Armitage & Gobas (2007). Their presumption is 

that if log KOA > 5, log KOW >2 and the rate of chemical transformation is low, the chemical may 

biomagnify in terrestrial food chains. Even though an official reference or guideline to distinguish 

chemicals that biomagnify has not been established, Gobas et al. and Armitage & Gobas’ 

presumption was utilized here as a broad reference to identify the potential for biomagnification 

in terrestrial food chains. Evidence of brodifacoum in the terrestrial food chains and information 

on its liver retention half-lives support the above mentioned presumption. EPI Suite v.4.1’s 

estimate of the fish bioconcentration factor (BCF) is 2450 L/kg wet-wt, with a very slow 

biotransformation rate (t1/2 = 351 days).
12

Brodifacoum is stable to hydrolysis at pH 5, 7, and 9, relatively persistent in soil (t1⁄2 = 157 

days), and immobile in soil columns. Aged column leaching studies indicated that parent 

brodifacoum is immobile in soil columns of UK sand, sandy clay loam, silty clay and clay. The 

EPI Suite v.4.1 estimated KOCs are on the order of 105 to 106 L/KgOC. Brodifacoum is persistent, 

but little, if any, contamination of surface and ground waters is expected because of its use pattern 

and immobility in soil. Because brodifacoum is typically applied in bait stations and/or only in 

and around structures, bait is only 25 or 50 ppm (0.0025 or 0.005%) a.i., and because it is immobile 

in soil, potential contamination of surface and ground water is expected to be low. Therefore, 

degradate identification, accumulation and decline, unaged column leaching, field dissipation, and 

adsorption/desorption data were not required.

Table 3. Summary of Brodifacoum Environmental Fate Properties

Study Value and Unit

Major 

Degradate

Minor 

Degradates

MRID No.

or Citation

Study 

Classification/ 

Comments

Hydrolysis

Half-life = 

No evidence of degradation at pHs

5, 7 and 9

Not applicable

42237701, 

43435801,

44021706

Acceptable; 

considered 

relatively stable

Atmospheric 

Oxidation 

Half-life = 

2.2 hours, hydroxyl radical reaction

2.0 hours, for ozone reaction

Not available

EPI Suite 

v.4.1 

Estimate

Not applicable

Aerobic Soil 

Metabolism

Half-life = 

157 days, sandy clay loam at 210C;

No organic volatiles, and 14CO2 at 

36% AR.

Up to 11 

degradates at up 

to 17.34% AR; 

they were not 

identified.

42579401

Acceptable;

only one soil is 

available

Organic-Carbon 

Normalized 

Distribution 

Coefficient 

(KOC)

KOC = 

7.745 x 106 L/kgOC (estimate from 

Molecular Connectivity Index)

1.411 x 105 L/kgOC (estimate from 

KOW)

Not available

EPI Suite 

v.4.1 

Estimate

Not applicable;

Immobile (FAO 

2000)

Aged Soil 

Column 

Leaching

Brodifacoum was aged for 30 days. 

Shows low mobility in sand, sandy 

clay loam, silty clay and clay soil 

columns. ≤0.32% was recovered in 

the leachates.

No major 

degradates were 

observed in soil 

or leachate.

42568301 Acceptable

Bioconcentration

Factor (BCF) 

Regression based BCF=

2450 L/kg wet-wt

Biotransformation t1/2 = 351 days 

(normalized to 10 g fish at 150C)

Not available

EPI Suite 

v.4.1 

Estimate

Not applicable

Abbreviations: wt=weight, NA=Not Available, N/A=Not Applicable, AR = Applied Radioactivity

5.1 Transformation Products

Up to eleven [14C] compounds other than [14C]brodifacoum were isolated from the soil 

extracts at 2.07 to 17.34% of the applied (0.008 to 0.067 ppm) in the aerobic soil metabolism study, 

but none were identified. The identification, accumulation and decline of major metabolites 

(17.34% of applied) were not required at the time of the review.
13

6. Receptors

6.1 Toxicity Summary

Brodifacoum has a relatively small dataset for aquatic organism toxicity. Freshwater fish 

and invertebrates exposed to dissolved chemical have demonstrated very high acute toxicity. No 

chronic effect data has been submitted for freshwater or marine/estuarine invertebrates or fish. 

There are no submitted acute data available for assessment of toxicity to aquatic plant species. See 

Table 4 for listing of most sensitive aquatic study endpoints reviewed by the Agency.

Brodifacoum is very highly toxic to birds and mammals on an acute oral and subacute 

dietary exposure basis. In addition to lethal effects observed in toxicity studies, birds and mammals 

were observed to have sublethal effects including hemorrhaging, weight loss, decreased activity 

levels, wing droop, loss of equilibrium, and lethargy and other sublethal effects. No chronic data 

has been submitted for the evaluation of chronic toxicity levels to birds or mammals who might not 

initially ingest a lethal dose. No data for evaluation of acute or chronic toxicity of brodifacoum to 

adult honey bees or their larvae is available. Finally, no data are available to characterize the toxicity 

to terrestrial plants. In the case of honey bee and terrestrial plants, the use of brodifacoum in tamper 

resistant bait boxes is expected to limit their potential exposure to these taxa. Table 5 below 

summarizes the most sensitive terrestrial organism toxicity endpoints for studies reviewed by the 

Agency to date.

6.1.1 Effects to Aquatic Organisms

Table 4. Summary of the Most Sensitive Endpoints from Aquatic Toxicity Studies for Brodifacoum 

Taxonomic 

Group

Study Type/ 

% active (ai) Test Species Toxicity Value

Acute Toxicity 

Classification

Source/ Study 

Classification

Freshwater fish1

Acute with 

92.5% ai

Rainbow Trout,

Oncorhynchus mykiss

96 hr LC50 = 

25 ug ai/L

Very Highly 

toxic

00066943

acceptable

Chronic Early 

Life- Stage -- No dataavailable

Freshwater 

invertebrates

Acute with 

93.3% ai

Water Flea,

Daphnia magna

48 hr EC50 = 

980 (900-

1800)ug ai/L

Highly toxic 00128442 

acceptable

Chronic Water Flea,

Daphnia magna -- No dataavailable

Estuarine/marine 

fish

Acute or 

Chronic

Sheepshead Minnow, 

Cyprinodon 

variegatus

No data

available

Estuarine/marine 

crustacean

Acute or 

Chronic

Mysid, Americamysis 

bahia

No data

available
14

Taxonomic 

Group

Study Type/ 

% active (ai) Test Species Toxicity Value

Acute Toxicity 

Classification

Source/ Study 

Classification

Estuarine/marine 

mollusc Acute Eastern Oyster, Crassostrea virginica

No data 

available

Aquatic plants 

and algae

Vascular Duckweed, Lemna sp. -- No data 

available

Non-vascular Algae - multiple 

species -- No data available

1 Freshwater fish may be surrogates for aquatic-phase amphibians.

6.1.2 Effects to Terrestrial Organisms

Table 5. Summary of Most Sensitive Endpoints from Terrestrial Toxicity Studies for Brodifacoum 

Taxonomic 

Group Study Type Test Species

Toxicity Value

(level of active 

ingredient)

Acute 

Toxicity 

Classification

Source/ Study

Classification 

Birds1

Acute oral Mallard duck

Anas platyrhynchos

LD50 = 0.26 (0-0.8) 

mg ai /kg

bodyweight

Very highly 

toxic

41563303

acceptable

Sub-acute 

dietary

Bobwhite quail, 

Colinus virginianus

40 Day LC50 = 0.8 

(0.1-4.7) mg ai/kg 

diet

Very highly

toxic

00124477

acceptable

Chronic No data available

Mammals

Acute Oral Laboratory rat 

Rattus norvegicus

LD50 = 0.42 mg

ai/kg-bodyweight 

(females)

Highly toxic 42687501 

acceptable

Acute 

Dietary Laboratory rat LC50 = 0.55 (0.45 -0.68) mg ai/Kg diet

Very Highly 

toxic

Test Number 

110 USEPA 

Beltsville, Md

Acute dietary Wild mammal

Vole Microtus sp.

LC50 = 1.4 (0.77-

2.0) mg ai/Kg diet

Very highly 

toxic

00080237

USFWS 

Denver lab

Chronic Laboratory rat 

Rattus norvegicus

No data currently available for 

NOAEL or LOAEL in mg/kg/day

Insects Acute contact Honey bee 

Apis mellifera L. No Data available

Terrestrial 

plants

Seedling 

Emergence

Dicot – No Data available

Monocot No Data available

1 Birds represent surrogates for terrestrial-phase amphibians and reptiles.
15

6.2 Secondary Poisoning Potential

Numerous laboratory and field studies regarding acute effects from secondary poisoning 

through ingestion of contaminated carcasses or live prey have been submitted and reviewed for 

wild mammals and birds. This secondary poisoning could occur to adult birds feeding on poisoned 

carcasses or live animals as well as to young nesting birds when fed poisoned animal carcasses. 

These indirect adverse effects will be discussed in more detail in the characterization portions of 

the Registration Review. Citations for these studies as well as other studies related to exposure to 

and toxicity of Brodifacoum are included in the Ecological Effects Bibliography at the end of this 

document. 

Table 6 Summary of Submitted and Reviewed Secondary Toxicity Studies

Taxonomic

Group Study Type SpeciesInvestigated

Toxicological 

observations Source 

MRID/Author/Classification

Birds1

Acute-Nonguideline

Barn Owl, Tyto 

alba In review 00080241Morris, K.D. 1980

Owls

6 Barn owls fed rodents 

for 10 days- 5 owls died 

8-11 days after dosingsee Mendenhall, 1980

00080842- Mendenhall 1979

00094694- Mendenhall 1980

Supplemental

40777202-same as 00094694

46750931- same as 00094694

Raptors-Golden 

eagle Aquila 

chrysaetos, Redtailed hawk, Buteo 

jamaicensis Redshouldered hawk 

Buteo lineatus

Birds were fed treated 

rodents for 7-9 days

All 4 Eagles survived

All 4 RT hawks died

1 of 2 RS hawks died

00080243 - Marsh, R.E.; Howard, 

W.E. (1978)

Supplemental

Vole and American 

Kestral, Falco 

sparverius

3 day Vole LC50= 1.4 

ppm

4 of 10 Kestrels fed 

treated voles for 6 days 

died

00080244 - Savarie, P.J 1979.

Vole -supplemental

Kestrels- invalid

38 Screech owls 

(other species 

monitored)

Birds were studied in 15 

different orchardsbroadcasted pellets – 20 

owls died -9 had 

brodifacoum residues 

detected in liver 

00128240-Hegdal, P. 1980

Supplemental

00161158

American Kestrel, 

Falco sparverius To be reviewed 00080199Denver WRC – USFWS, 1981

Meadow Voles and 

other Wildlife

To be reviewed -residue 

levels from 10 ppm 

treated orchard

00085726

Gray and Red 

foxes

4 Red foxes and 1 gray 

fox fed poisoned rat meat 

1-4 days. 1 red and 

1gray fox died after 9 

days- others survived.

00128422, Morris, K.D.

Supplemental
16

Taxonomic

Group Study Type SpeciesInvestigated

Toxicological 

observations Source 

MRID/Author/Classification

Field 

Incident 

AnalysisRed tailed hawk, 

Barred owl, Great 

horned owl, and 

Eastern screech 

owl

Post mortem analysis

12 to 292 ppb – residue 

levels in liver of dead 

birds

I022978 Murray, M. 2011-

published open literature

Wildlife Clinic of Tufts 

Cummings School of Veterinary 

Medicine, MA

Field 

Incident 

analysis 

San Joaquin Kit 

fox

Post mortem analysisBrodifacoum detection 

(26 out of 30 or 87%)

dead foxes

McMillen et al 2008. Published 

open literature

I01600-001

Field

Incident 

analysis

Post mortem 

Raptor analysis (96 

birds) in California

brodifacoum residues 

detected in 83% of the 

birds while this number 

was 12% in the Central 

Valley birds

Lima and Salmon (2010) –

published open literature

6.3 Ecological Incidents

The Ecological Incident Information System (EIIS) is an OPP database that houses 

ecological incidents that have been reported to the Agency. When available, EIIS includes date and 

location of an incident, type and magnitude of effects observed in various species, use(s) of 

pesticides known or suspected of contributing to the incident, and results of any chemical residue 

analysis or other analyses conducted during incident investigation. EIIS incidents are categorized 

according to the certainty that the incident resulted from pesticide exposure. The Avian Information 

Monitoring System (AIMS) is a database administered by the American Bird Conservancy that 

contains publicly available data on reported avian incidents involving pesticides. Many of the 

incidents listed in this database are also in the EIIS. 

In a recent 2015 query of the EIIS system over 700 wildlife incident reports were obtained 

for brodifacoum use which far outnumbers incidents reported for any other currently registered 

rodenticide. The likelihood that an incident is caused by brodifacoum are classified with various 

certainty criteria based on the availability of a residue analysis of carcasses, visual verification of 

gross pathological observations such as hemorrhaging, or other evidence. For brodifacoum 

exposure certainty 296 were considered highly probable, 111 were considered probable and 108 

were considered possibly attributable to brodifacoum uses. 122 incidents were classified as either 

unlikely or unrelated to brodifacoum use, though some evidence was present that it was used along 

with other chemicals. 82 were reports of exposure to residues only.

The majority of incidents were reported in only 4 states. This is due to the fact that these 4 

states have more robust reporting systems and does not reflect that less incidents were necessarily 

occurring in other states, just that fewer were investigated or reported to the Agency by the other 

15 states which reported incidents. Though 31 states did not report any incidents for brodifacoum 

uses, this should not be considered as a lack of incidents within those states, but more a lack of 

processes to document incidents and report them to federal regulators. It should be noted that this 

is probably an underestimate of nationwide impact as 4 states reported 672 of these incidents 
17

(California, New York, Wisconsin, and Massachusetts). In preparation for the SAP to support the 

NOIC, the incidents reported from 1980 to 2012 were analyzed and summarized regarding the 

species involved and the certainty of the chemical exposure causing effects that were observed.

A number of the individual incidents observed in Massachusetts were summarized in a 

published study (Murray, M. 2011). This study documented residue analysis conducted on 80 Redtailed hawks, 40 Barred owls, 23 Eastern screech owls and 18 Great horned owls which were found 

dead or which subsequently died after showing adverse behavioral reactions and were brought to 

the Wildlife Clinic of Tufts Cummings School of Veterinary Medicine in North Grafton, MA. Of 

the 161 birds analyzed, 139 displayed residues of anticoagulant rodenticides in liver samples. 

Brodifacoum residues were found in the livers of 98% of these birds (136 of the 139 birds analyzed), 

thus indicating that widespread secondary exposure to poisoned prey was evident in the area from 

which the birds were found.

Over 200 incidents have been reported subsequent to the 2012 analysis and implementation 

of restricted use and bait box requirements imposed by the Agency. Further review and analysis of 

these additional incidents will be undertaken in the forthcoming Preliminary Risk Assessment.

Avian species suffering mortality by either primary exposure to the baits or by secondary 

exposure to contaminated carcasses or living organisms that had previously ingested brodifacoum 

baits include multiple species of hawks, eagles, seabirds, owls, vultures, quail, geese and passerine 

species. Mammalian poisoning incidents have involved predatory mammals such as bobcat, 

mountain lion, coyote, fox, and badger as well as non-predators such as raccoon, opossum, skunk, 

squirrels, non-target rodents, rabbits, and deer. These incidents involve Federally listed and nonlisted species.

7. Exposure Pathways of Concern

For most conventional pesticides, potential transport mechanisms typically include surface 

water runoff and spray drift. However, because the only use of brodifacoum is in bait for rodent 

control, no potential for spray drift exists, and exposure from volatilization is expected to be 

minimal due to the chemical’s low vapor pressure and Henry’s Law Constant.

7.1 Aquatic Exposure

Because brodifacoum bait is applied in stations outdoors, little potential exists for residues 

of brodifacoum to leach (or be extracted) from the bait station, if exposed to normal rainwater or 

runoff. Furthermore, due to the extremely low concentration of active ingredient in the bait (0.0025 

or 0.005%), the small amount applied per placement (~0.0001 lb a.i./placement), and the 

hydrophobic nature of the compound (log KOW = 8.5), leaching of dissolved brodifacoum from the 

bait station would be so small that the potential for contaminating surface water is expected to be 

limited. Similarly, exposure of surface water via erosion of soils that sorb brodifacoum is also 

expected to be negligible.
18

One possible exception would be the use of the chemical in sewers systems. The concern 

for sewer use is, both in the sewer (i.e., non-target organisms may visit sewers), and below the 

sewer discharge (e.g., chunks of bait blocks could be knocked or broken off as bait is eaten, 

discharged with stormwater or sewage overflow, and then consumed by non-target organisms). 

However, for the uses on sewer systems, instructions indicate to thread wire through blocks and 

securely attach to a stationary structure such as the bottom step of a manhole ladder or a sewer 

grate, allowing just enough wire for the block to rest on manhole benching. If benching is not 

present, blocks should be suspended a few inches above the high water mark, thus preventing 

removal by rats or water.

7.2 Terrestrial Exposure

The likely route of transport is within the bodies of animals which feed on the brodifacoum 

bait. Because these poisoned animals are not killed immediately, they may travel a significant 

distance before dying, thereby potentially exposing other animals away from the application site. 

This transport within animals is the major route of exposure for larger terrestrial animals whose diet 

includes small mammals, birds, and reptiles, thus making them vulnerable to secondary exposure 

from consuming poisoned prey. This hypothesis is supported by numerous incidents in which 

animals too large to enter the bait boxes are found to contain significant levels of residues in liver 

or other tissues upon post mortem examinations. In addition, insects such as ants or cockroaches 

are sometimes attracted to the bait and may feed on it or transport it outside of the bait boxes where 

they, as well as the bait particles, may be consumed by insectivorous wildlife. 

Use of brodifacoum in bait products to control rodent pests is not expected to result in 

significant exposure to plants. Bait is generally placed by hand in specific bait stations around 

buildings. The products containing brodifacoum should not be broadcasted. Any exposure to plants 

would be minor and limited to the area immediately around the bait placement.

8. Analysis Plan

8.1 Stressors of Concern

8.1.1 Ecological Risk Assessment

For this assessment brodifacoum is the stressor of ecological concern for terrestrial and 

aquatic organisms, though exposure to aquatic habitats may be limited. There is no information 

about possible degradates of brodifacoum that could be derived from the available environmental 

fate studies. The only exception is that one degradate was observed in the aerobic soil metabolism 

study at around 17% of the applied radioactivity but it was not identified. Brodifacoum is relatively 

persistent in studies performed to assess its half-life in livers of mice. Thus, it remains intact for 

several months if taken at sublethal levels (6.44 μg a.i./mouse, Vandenbroucke et al., 2008) and it 

appears unlikely that major (≥10% AR) metabolites would be formed in animal tissues.
19

8.1.2 Drinking Water 

As noted in Section 4.2, a drinking water assessment has not been previously conducted on 

brodifacoum. Because brodifacoum bait may be used outdoors in bait stations, little potential exists 

for residues of brodifacoum to leach from the bait station, if exposed to rainwater or runoff. 

However, due to the extremely low concentration of active ingredient in the bait (0.0025 or 

0.005%), small amount applied per placement, and the hydrophobic nature of the compound (log 

KOW = 8.5), leaching of dissolved brodifacoum from the bait would be so small that the potential 

for contaminating surface or ground water is expected to be insignificant. Similarly, exposure of 

surface water via erosion of soils that sorbed brodifacoum is also expected to be negligible. 

Therefore, a drinking water assessment for brodifacoum is not anticipated to be required.

8.2 Measures of Exposure

Exposure assessment methods employed by the Agency for the rodenticides differs from 

that for most other pesticides. For a rodenticide, the bait itself is the potential food item of concern. 

Thus, the amount of active ingredient in the formulated bait is used as an estimated environmental 

concentration (EEC). This information is used to estimate the amount of grain bait that birds and 

mammals of various sizes need to consume to obtain a dose expected to be lethal to 50% of the 

individuals in the population (i.e., LD50 dose).

8.2.1 Estimating Primary Exposure for Terrestrial Organisms

For birds and mammals, the assessment is based on the maximum concentration of 

brodifacoum in bait products used for rodent control. The maximum concentration is 0.005% (50 

mg a.i./kg product) for products used to control rats and mice. For dietary-based risk, the 

concentration of brodifacoum in the bait is compared directly to the toxicity endpoint from dietary 

toxicity studies (i.e., 40-day LC50 studies for birds and 14-day LC50 studies for mammals due to 

delayed toxicity of brodifacoum). For dosed-based risk, the brodifacoum concentration in bait has 

to be converted to a daily ingestion rate first. This is done using the allometric equations of Nagy 

(1987), as provided in USEPA’s Wildlife Exposure Factor Handbook (USEPA, 1993) – see Table 

7 below. Ingested doses of brodifacoum (mg a.i./kg-BW) will be calculated for birds and mammals 

of various assumed body weights. The doses calculated for birds could also be used for reptiles 

and terrestrial-phase amphibians. This approach is consistent with other rodenticide risk 

assessments conducted by the Agency.

Table 7. Direct Exposure

Formulas for Calculation of Daily Intake Based on Consumption of Bait from Bait Boxes

Passeriform bird food intake (g, dry weight): FI (g dry-wt/day) = 0.398 * Wt(g)0.850

Rodent mammal food intake (g, dry weight): FI (g dry-wt/day) = 0.621 * Wt(g)0.564

Food intake (g, wet weight): FI (g wet-wt/day) = FI (g dry-wt/day) / 0.90

Brodifacoum intake (mg a.i./kg-bwt/day) = FI (g wet-wt/day) * mg a.i./kg-bait / Wt(g)
20

Where: Wt(g) = weight (in grams) of the bird or mammal consumer

 mg a.i./kg-bait = 25- 50 mg ai depending on brodifacoum concentration in bait

8.2.2 Accumulation through Multiple Feedings on Bait 

Available data on the retention times of brodifacoum in animal tissues was assessed by the 

Agency in the 2010 White Paper for the Science Panel review. Due to the attractiveness of bait 

formulations within the bait boxes and the longer time to death from exposure to second generation 

rodenticides, smaller animals may revisit the bait stations more than once and thus could obtain 

higher residue levels than single feed calculations might predict. Given the long retention time 

within tissues these levels are expected to increase incrementally if target or non-target animals 

return to feed multiple times before death occurs (4-9 days for Brodifacoum in rats). This can have 

implications for secondary toxicity assuming continually increasing accumulation levels within the 

potential prey of scavenging or predatory animals which feed on them. Accumulation of 

brodifacoum within the prey animal over time would be calculated using an elimination rate 

constant based on the liver half-lives to approximate elimination. As can be seen in Table 8 below 

organisms may feed for days before death ensues.

Table 8. Brodifacoum Residue Levels in Primary Consumers (Extracted from 2010 White Paper)

Mg a.i./kg 

bait

Target 

species Site Sample size

Days 

exposed

Mean whole-carcass 

residue in mg a.i /kgcarcass (range)Reference

50 Rat Field 50 Unknown Most < 7

Some up to 11-13 Kaukeinen 1993a

50 Rat Field 6 Unknown 2.7 (0.1-6.6) ICI America 

1979c

50 Rat Field

5 male

4 female

3 juvenile

Unknown

7.08 (3.92-9.17)

5.61 (1.39-12.19)

8.63 (1.77-25.97)

Howald 1997

50 Vole Field 74 1-7 4.07 ± 0.20 (SE) Merson et al. 

1984

50 Vole Field 62 1-7 2.07 ± 0.17 (SE) Merson et al. 

1984

50 Vole Lab 15 male

15 female

4

4

5.21 ± 2.06 (sd)

2.17 ± 1.17 (sd) Kaukeinen 1982

25b Deer mouse Field 10 4-9 2.71 (0.68-4.25) Howald et al. 

2001

20b Mouse Lab nr 3 2.21 Anonymous 

1981a

20b Mouse Lab 10 1 0.44 Newton et al. 

1990

10b Vole Lab 15 male

15 female

4

4

0.53 ± 0.24 (sd)

0.40 ± 0.20 (sd) Kaukeinen 1982

10b Vole Field 43 1-7 0.35 ± 0.03 (SE) Merson et al. 

1984

nr = not reported NA = not available sd-Standard deviation a Cited in US EPA (2004) Potential Risks of Nine Rodenticides to Birds and Nontarget Mammals: a Comparative Approach 

b baits registered in the U.S. are 0.005% a.i.
21

8.2.3 Estimating Secondary Terrestrial Exposure

Secondary exposure analysis (from consumption of contaminated live organisms or 

carcasses) requires consideration of potential concentrations of residues in tissues of target and nontarget organisms that are commonly consumed by predators and scavengers, how long the residues 

might persist in body tissues, and the quantity of contaminated prey or portions of prey that are 

consumed over a period of time by the species in question. Studies recording residue concentrations 

for non-target animals fed rodents have been submitted by registrants and are available in open 

literature. In addition, significant numbers of brodifacoum incident reports include post mortem 

analysis of residues found in liver and other tissues. Given the long residence times of second 

generation rodenticides these analyses may prove invaluable in validating such estimates.

Brodifacoum has been shown to display significant retention time in liver tissues as well as 

blood after exposure. Retention times for brodifacoum in various laboratory small mammal species 

range from 113 to 350 days after initial dosage. Additional tested species (opossum and sheep) also 

were observed to retain hepatic residue levels for over 100 days. Table 9 below displays a number 

of study results for retention times in blood or liver tissue reviewed for brodifacoum. Further review 

of any additional data may be included in the registration review process.
22

Table 9 Retention of Brodifacoum in Blood and Liver

Species Dose (mg a.i./kg) # doses Blood t1/2a

(days)

Liver 

retentiona,b

(days)

Reference 

(MRID)

Mouse 6.44 μg/mouse 1 91.7 307.4 (t1/2) Vandenbroucke et al. 2008

Rat 0.02 or 0.15

0.35

1

1 NA 350c (t1/2)128d (t1/2)

Batten and Bratt 1990 

(42007502)

Rat 0.2 1 NA 282 (t1/2) Hawkins et al. 1991 

(42596801)

Rat 0.25 1 NA 150-200 (t1/2) Bratt and Hudson 1979 

(00080235)

Rat 0.06

4

(at weekly 

intervals)

NA 136 (t1/2) Belleville 1991 (42065009)

Rat 0.35 1 NA 130 (t1/2) Parmar et al. 1987e

Rat unknown unknown 6.5 >80 Backmann and Sullivan 

1983f

Rat 0.1 1 NA 113.5 (t1/2) Fischer et al. 2003 

(48190801)

Possum 0.1 1 20-30 >252 Eason et al. 1996

Rabbit unknown unknown 2.5 NA Brechenridge et al. 1985f

Sheep 0.2 or 2.0 1 NA >128 Laas et al. 1985e

Dog unknown unknown 6 NA Woody et al. 1992f

Dog unknown unknown 0.9-4.7 NA Robben et al. 1998f

a t1/2 for plasma and liver is the elimination half-life b liver retention is expressed as either the time period for which residues persist or as the elimination half-life c the elimination half-life of 350 days is for a single oral dose of 0.02 or 0.15 mg a.i./kg; elimination was not biphasic d the elimination half-life of 128 days is the terminal phase for a single oral dose of 0.35 mg a.i./kg; elimination was biphasic e Cited in US EPA (2004) Potential Risks of Nine Rodenticides to Birds and Nontarget Mammals: a Comparative Approach

f cited in Eason et al. 2001

8.2.4 Estimating Aquatic Exposure

Brodifacoum is restricted to use within tamper proof bait boxes or in cloth bags inserted 

into burrows. This limits the exposure pathways which could potentially result in aquatic exposure

for products applied to soil surfaces. Furthermore, as described in Section 7, due to the extremely 

low concentration of active ingredient in the bait (0.0025 or 0.005%), the small amount applied per 

placement, and the hydrophobic nature of the compound (log KOW = 8.5), leaching of dissolved 

brodifacoum from the bait station would be so small that the potential for contaminating surface 

water is expected to be insignificant. Similarly, exposure of surface water via erosion of soils that 

sorb brodifacoum is also expected to be negligible. Therefore, a modeling effort for aquatic 

exposure estimation is not being conducted for current registered outdoor uses.

8.2.5 Available Water Monitoring Data

The Agency is not aware of water monitoring conducted by federal and state agencies for 

brodifacoum. If new data for brodifacoum becomes available it may be considered in the 

preliminary assessment; however, water monitoring programs generally monitor for conventional 
23

agricultural pesticides and typically do not include analysis for vertebrate control agents such as 

brodifacoum.

8.3 Measures of Effect 

Toxicity data presented in Section 6 of this problem formulation will be used to calculate 

risk quotients. Any additional information submitted by the registrant or found in the open literature 

prior to conduct of the risk assessment will also be considered. Open literature studies are often

identified using EPA’s ECOTOXicology database (www.epa.gov/ECOTOX ), which employs a 

literature search engine for locating chemical toxicity data for aquatic life, terrestrial plants, and 

wildlife. The evaluation of both sources of data can also provide insight into the direct and indirect 

effects of pesticides on biotic communities from loss of species that are sensitive to the chemicals 

and from changes in structure and functional characteristics of the affected communities.

9. Endangered Species Assessments

Consistent with EPA’s responsibility under the Endangered Species Act (ESA), the Agency 

will evaluate risks to federally listed threatened and endangered (listed) species from registered 

uses of pesticides in accordance with the Joint Interim Approaches developed to implement the 

recommendations of the April 2013 National Academy of Sciences (NAS) report, Assessing Risks 

to Endangered and Threatened Species from Pesticides. The NAS report outlines 

recommendations on specific scientific and technical issues related to the development of pesticide 

risk assessments that EPA and the Services must conduct in connection with their obligations under 

the ESA and FIFRA. EPA will address concerns specific to brodifacoum in connection with the 

development of its final registration review decision for brodifacoum. 

In November 2013, EPA, the U.S. Fish and Wildlife Service, National Marine Fisheries (the 

Services), and USDA released a white paper containing a summary of their joint Interim 

Approaches for assessing risks to listed species from pesticides. These Interim Approaches were 

developed jointly by the agencies in response to the NAS recommendations, and reflect a common 

approach to risk assessment shared by the agencies as a way of addressing scientific differences 

between the EPA and the Services. Details of the joint Interim Approaches are contained in the 

November 1, 2013 white paper, Interim Approaches for National-Level Pesticide Endangered 

Species Act Assessments Based on the Recommendations of the National Academy of Sciences April 

2013 Report.

Given that the agencies are continuing to develop and work toward implementation of the 

Interim Approaches to assess the potential risks of pesticides to listed species and their designated 

critical habitat, this ecological problem formulation supporting the Preliminary Work Plan for 

brodifacoum does not describe the specific ESA analysis, including effects determinations for 

specific listed species or designated critical habitat, to be conducted during registration 

review. While the agencies continue to develop a common method for ESA analysis, the planned 

risk assessment for the registration review of brodifacoum will describe the level of ESA analysis 

completed for this particular registration review case. This assessment will allow EPA to focus its 

future evaluations on the types of species where the potential for effects exists, once the scientific 
24

methods being developed by the agencies have been fully vetted. Once the agencies have fully 

developed and implemented the scientific methods necessary to complete risk assessments for listed 

species and their designated critical habitats, these methods will be applied to subsequent analyses 

of brodifacoum as part of completing this registration review.

10. Endocrine Disruptor Screening Program

Brodifacoum was not included in the first group of 67 chemicals issued an order to conduct 

Tier 1 EDSP testing or the second list of 109 chemicals. For additional information the EDSP 

program, visit http://www2.epa.gov/endocrine-disruption. 

11. Preliminary Identification of Data Gaps 

11.1 Environmental Fate

Table 10 identifies environmental fate studies by MRID that offer data for each guideline 

requirement, as well as study classifications and whether or not further data are needed in order to 

support risk assessment.

Table 10. Submitted Environmental Fate Data for Brodifacoum

OCSPP 

Guideline

Data 

Requirement

Submitted 

Studies 

(MRID)

Study 

Classifications

Are data 

needed to 

conduct risk 

assessment?

Justification and Assumptions EPA 

will Make in Absence of Data

835.2120 Hydrolysis 42237701, 

43435801

44021706

Acceptable No --

835.2240 Aqueous 

photolysis

None Not applicable No --1

835.2410 Soil photolysis None Not applicable No --1

835.4100 Aerobic soil 

metabolism

42579401, 

43435802

Acceptable No1,2 Study conducted in only one soil. Study 

43435802 is a response to comments.

835.4200 Anaerobic soil 

metabolism

None Not applicable No --1

835.4300 Aerobic aquatic 

metabolism

None Not applicable No --1

835.4400 Anaerobic 

aquatic 

metabolism

None Not applicable No --1

835.1230 Adsorption/ 

desorption and 

leaching

42024501 Unacceptable No --

835.1240 42568301 Acceptable

835.1410 Volatility –

laboratory

None Not applicable No --1

835.6100 Terrestrial field 

dissipation

None Not applicable No --1
25

OCSPP 

Guideline

Data 

Requirement

Submitted 

Studies 

(MRID)

Study 

Classifications

Are data 

needed to 

conduct risk 

assessment?

Justification and Assumptions EPA 

will Make in Absence of Data

835.6200 Aquatic field 

dissipation

None Not applicable No --1

850.1730 Fish 

bioconcentration

None Not applicable No --1

850.6100 Analytical 

method in water

None Not applicable No --3

Analytical 

method in soil

None Not applicable No

1. Data have not been submitted to fulfill some guidelines. Data gaps were not identified as these data are not necessary 

for risk assessment at this time.

2. Study was conducted in only one soil, as opposed to the required four soils.

3. Studies are not recommended at this time because terrestrial exposure estimates are assumed to be either nondegraded bait, measured residues in tissues of animals that ingested brodifacoum, or estimated residues in tissues of 

animals that ingested brodifacoum. In the case of estimated residues, half-lives in liver will be used to account for 

degradation.

11.2 Effects

Table 11 and Table 12 identify submitted ecological effects studies by MRID that were 

reviewed for each guideline requirement, as well as study classifications and whether or not further 

data are needed in order to support risk assessment. Rationale for the additional data requested is 

presented below.

850.2100 Acute Oral Toxicity – Passerine Species

Smaller passerine species may be more sensitive than species previously tested with 

brodifacoum. Currently no data is available to clarify this uncertainty. This study is 

requested.

850.2300: Avian Reproduction Study: Little is known about the effects of low level sublethal dietary levels on reproductive success for non-target avian species. Brodifacoum is 

shown to accumulate in adult tissues and blood of birds who have presumably ingested 

contaminated prey, but not succumbed to these exposure levels. Due to the extreme acute 

toxicity of this chemical to birds a design protocol should be submitted before conduct of 

the studies for determination of test concentrations and methods. This guideline testing is 

requested for one upland game species and one waterfowl species.

850.1300 Chronic Lifecycle testing with Freshwater Invertebrate

850.1400 Early Lifestage Toxicity with Fish

Brodifacoum displays very high acute toxicity to freshwater invertebrate and fish species. 

Chronic studies with fish and invertebrate species are generally required for all nonresidential outdoor uses. Use in stormwater pipes or sewer system drains could potentially 

lead to exposure to aquatic habitats. However, for these uses, instructions indicate wire

should be threaded through blocks and securely attached to a stationary structure above high 

water level, thus reducing exposure potential. In addition, the hydrophobicity of the 
26

compound, precludes potential for residues of brodifacoum to be leached from the bait 

station if exposed to rainwater or runoff. Surface or groundwater exposure is expected to 

be negligible. Though lack of chronic data is an uncertainty for future assessments these 

studies are not requested at this time, as exposure potential is low for current labeled uses.

850.3020: Acute Contact Toxicity to Honeybees, 850.3030: Honeybee residues on 

Foliage, and Special Studies: Honeybee oral toxicity and adult and larval Chronic 

toxicity

These studies are generally required of most outdoor use pesticides to which honeybees may 

be exposed or to which hives may be exposed through transport back to the colony. Though 

currently considered an uncertainty with respect to actual toxicity to honeybees, uses 

restricted to bait boxes are not expected to expose honeybees to second generation 

rodenticides such as brodifacoum. In addition, other than under highly controlled 

Conservation uses, the current uses of brodifacoum are restricted to use near agricultural or 

industrial buildings, structures within commercial shipping areas such as docks or 

warehouses, or in transport vehicles such as rail cars or ships. Based on limited exposure 

potential, no honeybee studies will be required at this time.

Table 11. Submitted Aquatic Ecological Effects Data for Brodifacoum

OCSPP

Guideline

Data 

Requirement

Submitted 

Studies 

(MRID)/

Species

Study 

Classificatio

n

Are data 

needed to 

conduct risk 

assessment?

Justification and Assumptions 

EPA will Make in Absence of 

Data 

850.1010 Freshwater 

invertebrate 

acute toxicity

00066948

Daphnia magna

Invalid No Current data adequate for 

current uses as aquatic exposure 

potential is limited and will not 

be assessed 00128442 

Daphnia magna

TGAI

Supplemental

00128442 

Daphnia magna

TEP

Invalid

850.1025

850.1035

850.1045

850.1055

Saltwater 

invertebrate 

acute toxicity 

No data 

available

No Current data adequate for 

current uses as aquatic exposure 

potential is limited and will not 

be assessed

850.1075 Freshwater 

fish acute 

toxicity 

00066943 or 

00124472-RBT

Supplemental No Data is not needed for current 

uses as aquatic exposure 

potential is limited and will not 

be assessed 00066944 or 

00124473- RBT

Supplemental

00066945 or 

00124474- BG

Invalid

00066946 - RBT Supplemental

00066947- BG Supplemental

00088010 or 

00124470 - RBT

00088011 

or00124471- BG

Supplemental
27

OCSPP

Guideline

Data 

Requirement

Submitted 

Studies 

(MRID)/

Species

Study 

Classificatio

n

Are data 

needed to 

conduct risk 

assessment?

Justification and Assumptions 

EPA will Make in Absence of 

Data 

42641901- BG Invalid

850.1075 Saltwater fish 

acute toxicity 

No data 

available

No Data is not needed for current 

uses as aquatic exposure 

potential is limited and will not 

850.1300 Freshwater be assessed

invertebrate 

life cycle 

No data 

available

No

850.1350 Saltwater 

invertebrates 

life cycle 

No data 

available

No

850.1400 Freshwater 

fish 

early-life stage

No data 

available

No

850.1400 Saltwater fish 

early-life stage

No data 

available

No

850.1500 Fish life cycle No data 

available

No

850.4400 Aquatic plant 

Toxicity Test 

using Lemna 

spp.

No data 

available

No

850.4500 Algal toxicity No data 

available

No

850.4550 Cyanobacteria No data No

Table 12. Submitted Terrestrial Ecological Effects Data for Brodifacoum

OCSPP 

Guideline

Data 

Requirement

Submitted 

Studies (MRID)

Study 

Classification

Are data 

needed for 

risk 

assessment?

Justification and 

Assumptions EPA will Make 

in Absence of Data 

850.2100 Avian oral 

toxicity

00066942 with 

Mallard duck

Invalid Yes - for 

Passerine 

species only

These data are partially 

adequate for risk assessment of 

currently registered uses

Risk to smaller passerine 

species cannot be estimated and 

sensitivity of this group may be 

higher than previously tested 

species

41563803 with 

Mallard duck

Acceptable

46351303 with 

Ring neck 

pheasant

Supplemental

46351304 with 

Japanese quail -

Supplemental

46351302 with 

Domestic 

chicken

Supplemental
28

OCSPP 

Guideline

Data 

Requirement

Submitted 

Studies (MRID)

Study 

Classification

Are data 

needed for 

risk 

assessment?

Justification and 

Assumptions EPA will Make 

in Absence of Data 

850.2200 Avian dietary 

toxicity 

00080232 or

00080236 with 

Laughing gull

Invalid No These data are adequate 

for risk assessment of currently 

registered uses

00097936 with 

Mallard duck

Acceptable

00097937 with 

Bobwhite quail

Acceptable

00124475 with 

Mallard duck

00124476 

Mallard duck-40 

day study

Acceptable

00124477

Bobwhite quail 

40 day study

Acceptable

850.2300 Avian 

reproduction

Gamebird Yes Feasibility of these long term 

studies to be determined after 

protocol review Waterfowl

NonguidelineAvian 

inhalation

No data available No Volatility of brodifacoum is 

low

Non 

Guideline

Avian 

Secondary 

Toxicity

40077205 with 

Barn owls

Supplemental No These data are considered 

supplemental and useful for 

risk assessment purposes to 

characterize risk potential for 

secondary toxicity

00080239 with 

Barn owl

Supplemental

00080241 with 

Barn owl

Supplemental

40077202 with 

Barn owl

Supplemental

40077207 with 

Chukar

Supplemental

00080199 with 

American kestrel

Falco sparverius

Supplemental

00080243 with 

Raptor species

Supplemental

00161693 with 

Screech owl

Supplemental

Wild and 

Laboratory 

Mammal 

Acute toxicityoral or dietary

00080237 with 

Vole

Oral and 

Dietary/ 

Supplemental

No These data are considered 

supplemental and useful for 

risk assessment purposes

00080248 with 

Mink

Oral

Supplemental

00087134 with 

dog and cat

Oral

Invalid
29

OCSPP 

Guideline

Data 

Requirement

Submitted 

Studies (MRID)

Study 

Classification

Are data 

needed for 

risk 

assessment?

Justification and 

Assumptions EPA will Make 

in Absence of Data 

TNM 0501

Laboratory rat

Dietary

Supplemental

TNM 0791

Laboratory rat

Dietary

Supplemental

TNM 0821

Laboratory rat

Dietary

Supplemental

TNM 1101

Laboratory rat

Dietary rat

Supplemental

TNM 1121

Laboratory rat

Dietary rat

supplemental

00074376

00084356

Meadow voles

Field exposure

48638401

Richardson’s 

ground squirrel

Supplemental

Secondary 

toxicitymammals

128422 Red and 

Gray foxes fed 3-4 

days

Supplemental These data are considered 

supplemental and useful for 

risk assessment purposes

850.3020 Honey bee 

acute contact 

toxicity

No data available No These data are not needed at 

this time for risk assessment of 

currently registered uses

Burrow or bait box use not 

expected to expose honeybees

850.3030 Honey bee 

residue on 

foliage

No data available No

850.3040 Field testing 

for pollinators

No data available No

850.4100 Seedling 

Emergence

and Seedling 

Growth

No data available No These data are not needed at 

this time for risk assessment of 

currently registered uses

850.4150 Vegetative 

Vigor

No data available No

1 Studies conducted at the USEPA Animal Biology Lab in Beltsville, Maryland
30

12. References 

Albert, C.A., L.K. Wilson, P. Mineau, S. Trudeau, and J.E. Elliott. 2009. Anticoagulant 

 Rodenticides in Three Owl Species from Western Canada, 1988–2003 Arch

 Environmental Contamination Toxicology. 

Armitage, J.M., & Gobas, F.A.P.C. 2007. A terrestrial food-chain bioaccumulation model for 

POPs. Environmental Science and Technology, 41, 4019-4025.

Arnot, J. A., & Gobas, F. A. P. C. 2004. A food web bioaccumulation model for organic chemicals 

in aquatic ecosystems. Environmental Toxicology and Chemistry, 23(10), 2343-2355.

Cox, P. and R.H. Smith. 1992. Rodenticide ecotoxicology: pre-lethal effects of anticoagulants on 

rat behavior. Proc. Vertebr. Pest Conf. 15:165-170.

Food and Agriculture Organization of the United Nations. FAO PESTICIDE DISPOSAL SERIES 

8. Assessing Soil Contamination: A Reference Manual. Appendix 2. Parameters of 

pesticides that influence processes in the soil. Editorial Group, FAO Information Division: 

Rome, 2000. http://www.fao.org/DOCREP/003/X2570E/X2570E00.htm (accessed 

08/25/2015).

Gobas, F.A.P.C., B.C. Kelly and J.A. Arnot. 2003. Quantitative structure activity relationships for 

predicting the bioaccumulation of POPs in terrestrial food webs. QSAR Comb. Sci. 22:329-

336.

Howald GR, Mineau P, Elliott JE, Cheng KM (1999) Brodifacoum poisoning of avian scavengers

 during rat control on a seabird colony. Ecotoxicology 8:431–447

Lutz, W. 1986. Study on the possible secondary hazards to buzzards (Buteo buteo) by the 

rodenticide brodifacoum. Report for BBA, Bonn, Germany. 

Masuda, B.M, Fisher, P., and Beaven, B. 2015. Residue profiles of brodifacoum in coastal marine 

species following an island rodent eradication. Ecotoxicol. Environm. Saf., 113 (2015), pp. 

1-8.

Murray, M. 2011. Anticoagulent Exposure and Toxicosis in Four Species of Birds of Prey 

Presented to a Wildlife Clinic in Massachussetts, 2006-2010. Journal of Zoo and Wildlife 

Medicine 42(1):88-97. (also assigned Incident Number I022978 in USEPA/ OPP Incident 

data system (IDS).

Pelfrene, A.F. 1991. Synthetic organic rodenticides. Handbook of Pesticide Toxicology, vol. 3: 

Classes of Pesticides, pages 1271-1316. Academic Press, Inc.

USEPA. 1993. Wildlife Exposure Handbook. Office of Research and Development, United States 

Environmental Protection Agency. Available at http://www.epa.gov/ncea/pdfs/toc2-37.pdf

(accessed June 19, 2009). 

USEPA. 1998a. Guidelines for Ecological Risk Assessment. United States Environmental

Protection Agency (USEPA). Risk Assessment Forum. Office of Research and 

Development.

USEPA. 1998b. Reregistration Eligibility Decision (RED): Rodenticide Cluster. EPA738-R-98-

007. 319 pp. http://www.epa.gov/pesticides/reregistration/status_page_r.htm#rodenticides

(accessed 08/25/2015), and see docket EPA-HQ-OPP-2006-0955, available at

www.regulations.gov.

USEPA. 2004a. Overview of the Ecological Risk Assessment Process in the Office of Pesticide 

Programs. United States Environmental Protection Agency (USEPA). Environmental Fate 

and Effects Division. Office of Pesticide Programs. Available at

http://archive.epa.gov/pesticides/reregistration/web/pdf/ecorisk-overview.pdf (accessed 

10/23/2015).
31

USEPA. 2004b. Potential Risks of Nine Rodenticides to Birds and Nontarget Mammals: A 

Comparative Approach. Environmental Fate and Effects Division. Office of Pesticide 

Programs.

USEPA. 2008a. OPPTS 835.6100 Terrestrial Field Dissipation. EPA 712-C-08-020. October 2008. 

Office of Chemical Safety and Pollution Prevention (formerly Office of Prevention, 

Pesticides, and Toxic Substances). United States Environmental Protection Agency. 

Available at http://www2.epa.gov/test-guidelines-pesticides-and-toxic-substances/series835-fate-transport-and-transformation-test (accessed 10/23/2015).

USEPA. 2008b. Risk Mitigation Decision for Ten Rodenticides (EPA-HQ-OPP-2006-0955-0764). 

Office of Chemical Safety and Pollution Prevention (formerly Office of Prevention, 

Pesticides, and Toxic Substances). Office of Pesticides Program. Available at 

www.regulations.gov.

USEPA. 2012. Risks of Brodifacoum Use to the Federally Threatened Alameda Whipsnake 

(Masticophis lateralis euryxanthus), and the Federally Endangered Salt Marsh Harvest 

Mouse (Reithrodontomys raviventris) and San Joaquin Kit Fox (Vulpes macrotis mutica). 

Pesticide Effects Determination. Environmental Fate and Effects Division. Office of 

Pesticide Programs. March 30, 2012. Available at 

http://iaspub.epa.gov/apex/pesticides/f?p=CHEMICALSEARCH:7:0::NO:1,3,31,7,12,25:

P3_XCHEMICAL_ID:1585 (accessed 10/23/2015).

USEPA. 2015. Estimation Programs Interface SuiteTM for Microsoft® Windows, v 4.11. United 

States Environmental Protection Agency, Washington, DC, USA. Available at 

http://www2.epa.gov/tsca-screening-tools/epi-suitetm-estimation-program-interface (site 

accessed 10/23/2015).

USFWS. 1993. U.S. Fish and Wildlife Service Biological Opinion. Effects of 16 Vertebrate Control 

Agents on Threatened and Endangered Species. U.S. Fish and Wildlife Service.

Vandenbroucke, Virgine, et al. 2008. Multi-residue analysis of eight anticoagulant rodenticides in 

animal plasma and liver using liquid chromatography combined with heated electrospray 

ionization tandem mass spectrometry. Journal of Chromotography B. Vol 869, Issues 1-2, 

15 June 2008, pages 101-110.

Watt, B.E., A.T. Proudfoot, S.M. Bradberry, and J.A. Vale. 2005. Anticoagulant rodenticides. 

Toxicol. Rev. 24(4):259-269.Yu, C.C., Y.H. Atallah, and D.M. Whitacre. 1982. Metabolism 

and disposition of diphacinone in rats and mice. Drug Metabolism and Disposition 10:645-

648.

FOR A BIBLIOGRAPHY OF STUDIES SUBMITTED TO EPA, SEE THE APPENDIX A.
32

Appendix A. Brodifacoum Bibliography

112701 Brodifacoum Fate/Chemistry Bibliography

161-1 Hydrolysis

MRID Citation Reference

129702 Hendley, P.; Lightfoot, Y. (1978) Brodifacoum: Hydrolysis in Aqueous Systems in 

the Dark: RJ 0047A. (Unpublished study re- ceived Mar 30, 1979 under 10182-26; 

prepared by Imperial Chem- ical Industries, Ltd., Eng., submitted by ICI Americas, 

Inc., Wilmington, DE; CDL:237938-C) 

42237701 Jackson, R.; Priestly, I.; Hall, B. (1992) The Determination of the Hydrolytic 

Stability of ?carbon 14|-Brodifacoum: Lab Project No. 381420: 8330. Unpublished 

study prepared by Inveresk Research International. 77 p. 

43435801 Griggs, R. (1994) Response to Comments in EPA Letter Dated 10-28-93 

Concerning Brodifacoum Hydrolysis Study: MRID 422377-01: Lab Project Number: 

381420. Unpublished study prepared by Inveresk Research International Ltd. 10 p. 

44021706 Mathis, S.; Benner, J.; Skidmore, M. (1995) Brodifacoum: Aqueous Hydrolysis in 

pH5, pH7 and pH9 Solutions at 25 degrees C: Lab Project Number: 94JH253: 

RJ1927B. Unpublished study prepared by Jealott's Hill Research Station, Zeneca 

Agrochemicals. 56 p. 

162-1 Aerobic soil metabolism

MRID Citation Reference

129701 Arnold, D.; Rapley, J.; Weissler, M. (1978) Brodifacoum: The Degradation of the 

Pesticide in Soil under Laboratory Condi- tions: Report Series RJ 0040B. 

(Unpublished study received Mar 30, 1979 under 10182-26; prepared by Imperial 

Chemical In- dustries, Ltd., Eng., submitted by ICI Americas, Inc., Wilming- ton, 

DE; CDL:237938-B) 

42579401 Hall, B.; Priestly, I. (1992) Brodifacoum: Metabolism in Soil under Aerobic 

Conditions: Lab Project Number: 381441. Unpublished study prepared by Inveresk 

Research International. 63 p. 

43435802 Griggs, R. (1994) Response to Comments in EPA Letter Dated 10-28-93 

Concerning Brodifacoum Aerobic Soil Metabolism Study: MRID 425794-01: Lab 

Project Number: 381441. Unpublished study prepared by Inveresk Research 

International Ltd. 23 p. 

80250 ICI Americas, Incorporated (1979?) Degradation of Brodifacoum in Soil under 

Laboratory Conditions. Summary of studies 245705-B through 245705-E. 

(Unpublished study received Jul 22, 1981 under 10182-38; CDL:245705-A) 

80251 Arnold, D.J.; Rapley, J.H.; Weissler, M.S. (1979) Brodifacoum: Development of 

Methods To Study Its Degradation in Soil: Report Series RJ 0064 B. (Unpublished 

study received Jul 22, 1981 under 10182-38; prepared by Imperial Chemical 

Industries, Ltd., England, submitted by ICI Americas, Inc., Wilmington, Del.; 

CDL:246705-B) 

163-1 Leach/adsorption/desorption
33

MRID Citation Reference

80252 Stevens, J.E.B.; Hill, I.R. (1979) Brodifacoum: Leaching on Soil Thick-layer 

Chromatograms: Report Series RJ 0072 B. (Unpub- lished study received Jul 22, 

1981 under 10182-38; prepared by Imperial Chemical Industries Ltd., England, 

submitted by ICI Americas, Inc., Wilmington, Del.; CDL:245705-D) 

157733 Newby, S.; White, B. (19??) Brodifacoum: Adsorption and Desorption in Soils 

Measured Under Laboratory Conditions: TMJ 1764B. Un- published study 

prepared by ICI. 54 p. 

42024501 Newby, S.; White, B. (1979) Brodifacoum: Adsorption and Desorption in Soils 

Measured Under Laboratory Conditions: Lab Project Number: TMJ 1764 B. 

Unpublished study prepared by ICI Agrochemicals 59 p. 

42568301 Jackson, R.; Hall, B. (1992) Aged Soil Leaching of [carbon 14] Brodifacoum: Lab 

Project Number: 381986. Unpublished study prepared by Inveresk Research 

International. 72 p. 

92195018 Skidmore, M. (1990) ICI Americas Inc. Phase 3 Summary of MRID 00157733. 

Brodifacoum: Adsorption and Desorption in Soils Measured under Laboratory 

Conditions: Report No. TMJ 1764B. Prepared by ICI AGROCHEMICALS 

JEALOTT'S HILL. 21 p. 

164-1 Terrestrial field dissipation

MRID Citation Reference

157963 Ussary, J. (1979) Brodifacoum Dissipation in Soil: (Interim Report): TMU 0424/B. 

Unpublished study prepared by ICI Americas Inc. 8 p. 

Non Guideline Selections

142798 Bland, P. (1983) Pesticide Formulations: High Pressure liquid chromatographic 

determination of Brodifacoum in formulations: Collaborative study. J. Assoc. Off. 

Anal. Chem. 66(4):993-998. 

Acc. No. 

237938.

K. G. Koubek and J. P. Ussary. An HPLC Method For the Determination of 

Brodifacoum in Soil. January 29, 1979. ICI Report Series TMU 0423/A. ICI 

Submission Vol IV, Reference 3J. EPA Acc. No. 237938.

Gowman, M.A. and D. Riley. Determination of the Physical and Chemical Properties 

of Soils. (Method in use at Jealott's Hill Research Station.) Report Series TMJ 

1190A. 19 January 1978. ICI Plant Protection Division. (confidential)

71-1 Avian Single Dose Oral Toxicity

MRID Citation Reference
34

66942

invalidated

Ross, D.B.; Roberts, N.L.; Cameron, D.M. (1978) The Acute Oral Tox- icity

(LDI50^) of PP 581 to the Mallard Duck: ICI 122WL/78507. (Unpublished 

study received Aug 15, 1978 under 10182-26; pre- pared by Huntingdon 

Research Centre, England, submitted by ICI Americas, Inc., Wilmington, Del.; 

CDL:234655-J) 

129705

Data summary

ICI Americas, Inc. (1979) Talon Rodenticide Containing Brodifacoum: ?Fish 

and Wildlife Safety Summary|. (Unpublished study re- ceived Jul 19, 1979 

under 10182-26; CDL:238840-A) 

41563303

Acceptable

Ross, D.; Roberts, N.; Fairley, C. (1990) Brodifacoum: The Acute Oral 

Toxicity (LD50) OF Brodifacoum to Mallard Duck: Lab Project Number: ICI 

308 WL/791275. Unpublished study prepared by Hunting don Research 

Centre. 24 p. 

46351303

Supplemental

Roberts, N.; Fairley, C. (1985) The Acute Oral Toxicity of Brodifacoum to the 

Ring-Necked Pheasant: Final Report. Project Number: ISN/13BT/85982, 

AX3474. Unpublished study prepared by Huntingdon Life Sciences, Ltd. 27 p.

46351302 Ross, D.; Roberts, N.; Cameron, D. (1977) The Acute Oral Toxicity (LD50) of 

PP581 to the Chicken: Final Report. Project Number: ICI/122WL/77600. 

Unpublished study prepared by Huntingdon Life Sciences, Ltd. 14 p.

46351304

Supplemental

Ross, D.; Roberts, N.; Cameron, D. (1977) The Acute Oral Toxicity (LD50) of 

PP581 to the Japanese Quail: Final Report. Project Number: 

ICI/122WL/77599. Unpublished study prepared by Huntingdon Life Sciences, 

Ltd. 14 p.

71-2 Avian Dietary Toxicity

MRID Citation Reference

80232

Invalidated

Fink, R.; Grimes, J. (1979) Final Report: Forty-day Dietary LC50-- Laughing 

Gull: Project No. 123-125. (Unpublished study received Jul 22, 1981 under 

10182-38; prepared by Wildlife International Ltd., submitted by ICI Americas, 

Inc., Wilmington, Del.; CDL: 245704-B) 

97936

Acceptable

Fink, R. (1976) Final Report: Eight-day Dietary LC50--Mallard Duck: PP 581 

Technical: Project No. 123-115. (Unpublished study re- ceived Jan 3, 1978 

under 10182-EX-10; prepared by Wildlife International, Ltd., submitted by ICI

Americas, Inc., Wilming- ton, Del.; CDL:232750-C) 

97937 

Acceptable

Fink, R. (1976) Final Report: Eight-day Dietary LC50--Bobwhite Quail: PP 

581 Technical: Project No. 123-114. (Unpublished study received Jan 3, 

1978 under 10182-EX-10; prepared by Wild- life International, Ltd., submitted 

by ICI Americas, Inc., Wilmington, Del.; CDL:232750-D) 

124475 Fink, R.; Beavers, J. (1978) Dietary LC50--Mallard Ducks: Technical 

Brodifacoum: Project No. 123-124. Final rept. (Unpublished study received 

Feb 27, 1979 under 10182-26; prepared by Wildlife International, Ltd., 

submitted by ICI Americas, Inc., Wilming- ton, DE; CDL:237703-F) 

124476

Acceptable

Fink, R.; Beavers, J.; Grimes, J.; et al. (1978) Forty-day Dietary LC50--

Mallard Duck: Technical Brodifacoum: Project No. 123-128. Final rept. 
35

(Unpublished study received Feb 27, 1979 under 10182-26; prepared by 

Wildlife International, Ltd. and Washington College, submitted by ICI 

Americas, Inc., Wilmington, DE; CDL:237703-H) 

124477

Acceptable

Fink, R.; Beavers, J.; Grimes, J.; et al. (1978) Forty-day Dietary LC50--

Bobwhite Quail: Technical Brodifacoum: Project No. 123- 127. Final rept. 

(Unpublished study received Feb 27, 1979 un- der 10182-26; prepared by 

Wildlife International, Ltd. and Wash- ington College, submitted by ICI 

Americas, Inc., Wilmington, DE; CDL:237703-I) 

143277 Lipha Chemicals, Inc. (1985) Toxicity Comparison between Talon and Maki: 

Lipha Report No. 85-013. Unpublished study. 4 p. 

80199

referenced

LaVoie, G.K. (1981) Secondary LCI50^ Study of the Toxicity of the 

Anticoagulant Brodifacoum to American Kestrels (~Falco spar~- ?~verius~: 

Work Unit 920.17. (Unpublished study received Jul 22, 1981 under 10182-

EX-21; prepared in cooperation with U.S. Fish and Wildlife Service, Denver 

Wildlife Research Center, sub- mitted by ICI Americas, Inc., Wilmington, Del.; 

CDL:245702-E) 

80233

Invalidated

Choice test

Ross, D.B.; Roberts, N.L.; Phillips, C.N.K. (1979) Assessment of the 

Palatability of Talon Pellets Containing 0.005% (50 ppm) Brodifacoum to the 

Bobwhite Quail: ICI 296 WL/79864; CTL/C/812. (Unpublished study received 

Jul 22, 1981 under 10182-38; pre- pared by Huntingdon Research Centre, 

England, submitted by ICI Americas, Inc., Wilmington, Del.; CDL:245704-C) 

80234

Invalidated

Ross, D.B.; Roberts, N.L.; Phillips, C.N.K. (1979) Assessment of the 

Palatability of Talon Pellets Containing 0.005% (50 ppm) Brodifacoum to the 

Ring-necked Pheasant: ICI 276 WL/781181. (Unpublished study received Jul 

22, 1981 under 10182-38; pre- pared by Huntingdon Research Centre, 

England, submitted by ICI Americas, Inc., Wilmington, Del.; CDL:245704-D) 

80236

Invalidated

Forty day LC50-Laughing Gull (1979) Test performance by Wildlife 

International for ICI Americdas, Inc. Accession on Number 245704, Volume II 

ref. February 9, 1979.

84343

Choice test

Kaukeinen, D.E.; Marsh, R.E.; Tobin, M.E. (1981) Volid: Laboratory 

Acceptance of Blank 3/16 Inch and 3/32 Inch Pellets to Sparrows, Finches, 

Robins and Starlings: Report Series TMUD3679/B. (Un- published study 

received Sep 10, 1981 under 10182-58; prepared in cooperation with Univ. of 

California--Davis, Agricultural Ex- periment Station, Wildlife and Fisheries 

Biology Div., sub- mitted by ICI Americas, Inc., Wilmington, Del.; 

CDL:245924-C) 

71-3 Domestic and Wild mammal toxicity

MRID Citation Reference

2467 Pank, L.F.; Hirata, D.N. (1976) Primary and Secondary Toxicity of 

Anticoagulant Rodenticides: Job Completion Report: Work Unit DF-103.7. 

(Unpublished study received on unknown date under unknown admin. no.; 

prepared by U.S. Fish and Wildlife Service, Denver Wildlife Research Center, 

Wildlife Damage Research Station, submitted by Velsicol Chemical Corp., 

Chicago, Ill.; CDL: 230307-B) 
36

80248

Supplemental

Ringer, R.K.; Aulerich, R.J.; Padgett, G.; et al. (1979) Determina- tion of Oral 

LDI50^ of Brodifacoum for Mink. (Unpublished study received Jul 22, 1981 

under 10182-38; prepared by Michigan State Univ., Dept. of Poultry Science, 

Fur Animal Project, submitted by ICI Americas, Inc., Wilmington, Del.; 

CDL:245704-S) 

92195006

Registrant 

summary

Kaukeinen, D. (1990) ICI Americas Inc. Phase 3 Summary of MRID 

00080248. Determination of the Oral LD50 of Brodifacoum for Mink: RR 90-

292 B. Prepared by MICHIGAN STATE UNIVERSITY 16 p. 

80200

Non-guideline 

study

Morris, K.D.; Jaber, M.B. (1981) Laboratory Comparison of Brodifacoum 

Tissue Residue in Voles Fed 10 0r 50 PPM Volid Pellets in a No-choice 

Feeding Situation for 3 Days: Report Series TMUE0006/B. (Unpublished 

study received Jul 22, 1981 under 10182-EX-21; prepared in cooperation 

with Virginia Tech and Analytical Biochemistry Laboratories, submitted by ICI 

Americas, Inc., Wilmington, Del.; CDL:245702-F) 

80247

Invalid- not 

useful

Parkinson, G.R. (1976) PP581: Acute Oral Toxicity to Sheep, September 

1976, Report No. CTL/P/259 (Revised 31 Jan. 1979). Acct # 245704. Only-2 

sheep tested

87134

Invalidated by 

HED

Parkinson, G.R. (1976) WBA 8119 Acute Oral Toxicity to Beagle Dogs and 

Cats. Jan. 1976. Acc. # 245704, Submitted by ICI Americas, Performed by 

English Part of Company.

80237

Reviewed-nonguideline

Kaukeinen, D.E.; Ussary, J.P.; Koubek, K.G. (1980) Brodifacoum Residues in 

Rodents, Pheasants and Ground Rat Tissue: Report Series TMU0545/B. 

Includes method GRAM-2 dated Jan 4, 1979 and undated method GRAMM2/I. (Unpublished study received Jul 22, 1981 under 10182-38; submitted by 

ICI Americas, Inc., Wilming- ton, Del.; CDL:245704-H)

No MRIDs USEPA Laboratory Rat Dietary Toxicity Studies at Beltsville Animal Biology 

Lab , Beltsville Md. Test Numbers 50, 82, 110, 112

48638401

Reviewed – see 

open lit

Baril, S., and G. Pallister. 1981. Laboratory Determinations of Acute Oral 

LD50 and Efficacy of Brodifacoum on the Richardson Ground Squirrel, 

Spermophilus richardsonii. Montanta Department of Agriculture 

Environmental Management Division. Technical Report 81-1.

71-5 Simulated or Actual Field Testing

MRID Citation Reference

139518

Invalidated

Kaukeinen, D.; Byers, R. (1981) Volak: Potential Hazard of the 50 ppm Black 

Pellet Broadcast at Three Rates As Indicated by Penned Ring-necked 

Pheasants: Report Series TMUD3451/B. (Un- published study received Apr 

29, 1983 under 10182-58; submitted by ICI Americas, Inc., Wilmington, DE; 

CDL:250077-C) 

40077201 Christopher, M.; Balasubramanyam, M.; Purushotham, K. (1984) Toxi- city of 

three anticoagulant rodenticides to (male hybrid leg- horns). A. Angew. Zool. 

71:275-281. 
37

40077205

J001726

Hegdal, P.; Blaskiewicz, R. (1984) Evaluation of the potential hazard to barn 

owls of Talon used to control rats and house mice. Environmental Toxicology 

Chemistry 3:167-179. 

40077207 Hoppe, A.; Krambias, A. (1982) The response of captive Chukar par- tridges 

to the ingredients and anticoagulant poisons used in ro- dent baits in Cyprus. 

P. 639-646 in Proceedings of a conference on the organization and practice 

of Vertebrate Pest Control; Aug 30-Sept 3, 1982, Elvetham Hall, Hampshire, 

England. 

74376

ACC 244802

Efficacymultiple field 

studiessupplemental

Kaukeinen, D.E.; Byers, R.; Merson, M.; et al. (1980) Volak^(TM)I: Efficacy to 

Meadow Voles and Wildlife Hazard from Broadcast Application of 50 ppm 

Pellets at 9.4 and 41 lb/A in a Dormant Apple Orchard (Virginia): Report 

Series TMUD3344/B. (Unpub- lished study received Apr 2, 1981 under 

10182-EX-12; prepared in cooperation with Virginia Polytechnic Institute, 

Winchester Fruit Research Lab., submitted by ICI Americas, Inc., Wilmington, Del.; CDL:244802-B)

84344 Choice 

test

Kaukeinen, D.E.; Morris, K.D. (1979) Volak: Effect of Candidate Avian 

Repellent Agents on Laboratory Group Acceptance of Blank Volak Pellets to 

Meadow Voles: Report Series TMUD2608/B. (Un- published study received 

Sep 10, 1981 under 10182-58; submitted by ICI Americas, Inc., Wilmington, 

Del.; CDL:245924-E) 

84345

Choice test

Kaukeinen, D.E.; Morris, K.D. (1979) Volak^(TM)I: Effect of Can- didate Avian 

Repellent Agents on Laboratory Group Acceptance of Blank Volak Pellets to 

Pigeons: Report Series TMUD2621/B. (Unpublished study received Sep 10, 

1981 under 10182-58; submit- ted by ICI Americas, Inc., Wilmington, Del.; 

CDL:245924-F) 

72-1 Acute Toxicity to Freshwater Fish

MRID Citation Reference

66943 or 

124472

supplemental

Hill, R.W. (1978) PP 581: Determination of the Acute Toxicity of PP 581 to 

Rainbow Trout (Salmo gairdneri): BL/B/1877. Includes undated method 

entitled: Analytical method for PP 581 in aqueous solution. (Unpublished 

study received Aug 15, 1978 under 10182- 26; prepared by Imperial 

Chemical Industries, Ltd., submitted by ICI Americas, Inc., Wilmington, Del.; 

CDL:234655-K) 

66944 Hill, R.W. (1978) PP 581: Determination of the Acute Toxicity of Formulation 

JFU 5074 to Rainbow Trout (Salmo gairdneri): BL/ B/1874. Includes undated 

method entitled: Analytical method for JFU 5074 in aqueous solutions. 

(Unpublished study received Aug 15, 1978 under 10182-26; prepared by 

Imperial Chemical Indus- tries, Ltd., submitted by ICI Americas, Inc., 

Wilmington, Del.; CDL:234655-L)

66945

supplemental

Hill, R.W. (1978) PP 581: Determination of the Acute Toxicity of Formulation 

JFU 5074 to Bluegill Sunfish (Lepomis macrochirus): BL/B/1879. Includes 

undated method entitled: Analytical method for JFU 5074 in aqueous 

solutions. (Unpublished study received Aug 15, 1978 under 10182-26; 

prepared by Imperial Chemical Industries, Ltd., submitted by ICI Americas, 

Inc., Wilmington, Del
38

66946

Supplemental

Will, R.W.; Clyburn, M. (1978) PP 581: Talon--Feeding Trials with Rainbow 

Trout (Salmo gairdneri): BL/B/1881. (Unpublished study received Aug 15, 

1978 under 10182-26; prepared by Imperial Chemical Industries, Ltd., 

submitted by ICI Americas, Inc., Wilmington, Del.; CDL:234655-N) 

66947

Supplemental

Hill, R.W.; Clyburn, M.M. (1978) PP 581: Talon--Feeding Trials with Bluegill 

Sunfish (Lepomis macrochirus): BL/B/1878. (Unpub- lished study received 

Aug 15, 1978 under 10182-26; prepared by Imperial Chemical Industries, 

Ltd., submitted by ICI Americas, Inc., Wilmington, Del.; CDL:234655-O) 

88010 or 

124470

Hill, R.W.; Maddock, B.G.; Hart, B.; et al. (1976) Determination of the Acute 

Toxicity of PP581 to Rainbow Trout (?~Salmo gaird~?- ?~nerii~?): 

BL/B/1758. (Unpublished study received Jan 3, 1978 under 10182-EX-10; 

prepared by Imperial Chemical Industries, Ltd., submitted by ICI Americas, 

Inc., Wilmington, Del.; CDL: 232750-E) 

88011 or 

124471

Not accepted

Hill, R.W.; Maddock, B.G.; Hart, B.; et al. (1976) Determination of the Acute 

Toxicity of PP581 to Bluegill Sunfish (?~Lepomis~ ?~macrochirus~?): Report 

BL/B/1771. (Unpublished study received Jan 3, 1978 under 10182-EX-10; 

prepared by Imperial Chemical In- dustries, Ltd., submitted by ICI Americas, 

Inc., Wilmington, Del.; CDL:232750-F) 

124473 or 

66944

Supplemental

Hill, R. (1979) PP 581: Determination of the Acute Toxicity of For- mulation 

JFU 5074 to Rainbow Trout: BL/B/1874. (Unpublished study received Feb 27, 

1979 under 10182-26; prepared by Imperial Chemical Industries, Ltd., Eng., 

submitted by ICI Americas, Inc., Wilmington, DE; CDL:237703-D) 

124474 or 

66945

invalidated

Hill, R. (1979) PP 581: Determination of the Acute Toxicity of Formulation 

JFU 5074 to Bluegill Sunfish: BL/B/1879. (Unpublished study received Feb 

27, 1979 under 10182-26; prepared by Imperial Chemical Industries, Ltd., 

Eng., submitted by ICI Americas, Inc., Wilmington, DE; CDL:237703-E) 

124472

66943

Supplemental

Hill, R. (1979) Determination of the Acute Toxicity of PP 581 to Rainbow 

Trout: BL/B/1877. (Unpublished study received Feb 27, 1979 under 10182-

26; prepared by Imperial Chemical Indus- tries, Ltd., Eng., submitted by ICI 

Americas, Inc., Wilmington, DE

143277 Lipha Chemicals, Inc. (1985) Toxicity Comparison between Talon and Maki: 

Lipha Report No. 85-013. Unpublished study. 4 p. 

42641901

Invalidated

Sankey, S.; Caunter, J.; Stanley, R. (1992) Brodifacoum: Acute Toxicity to 

Bluegill Sunfish (Lepomis macrochirus) of a 50 mg/kg Formulation: Lab 

Project Number: BL4614: W080/A: FT84/91. Unpublished study prepared by 

ICI PLC Group environmental Lab. 20 p. 

72-2 Acute Toxicity to Freshwater Invertebrates

MRID Citation Reference

66948

Invalidated

Getty, C.; Wilkinson, W.; Sealey, C. (1978) Brodifacoum: Toxicity to First 

Instar~Daphnia magna~: Report Series RJ0007 B. (Un- published study 

received Aug 15, 1978 under 10182-26; prepared by Imperial Chemical 
39

Industries, Ltd., submitted by ICI Ameri- cas, Inc., Wilmington, Del.; 

CDL:234655-P) 

128442

Supplemental –

TGAI

Invalid- TEP

Getty, C.; Wilkinson, W.; Sealey, C. (1978) Brodifacoum: Toxicity of the 

Liquid Concentrate Pelleted Bait and Technical Material to First Instar 

Daphnia magna: Report Series RJ0046B. (Unpub- lished study received 

Mar 29, 1974 under 10182-26; prepared by Imperial Chemical Industries 

Ltd., Eng., submitted by ICI Ameri- cas, Inc., Wilmington, DE; CDL:237909-

A) 

92195012

Registrant 

summary

Hamer, M. (1990) ICI Americas Inc. Phase 3 Summary of MRID 00128442. 

Brodifacoum: Toxicity of the Liquid Concentrate, Pelleted Bait and 

Technical Material to First Instar Daphnia magna: Report No. RJ0046B; 

Study No. PP518/CH/01. Prepared by ICI AGROCHEMICALS JEALOTT'S 

HILL RESEARCH STATION. 19 p. 

NON Guideline Studies - Many Secondary Toxicity Studies

80199 LaVoie. G.K., 1990. A study of the toxicity of the anticoagulant Brodifacoum 

to American kestrels (Falco sparverius). Proceedings of the Third 

International Conference on plant protection in the Tropics IV pp 27-29

80238

A Literature 

Search

Jaber, M.J. (1981) A Literature Search of the Dietary Habits of Avian 

Predators: Report Series TMUE0001/B. (Unpublished study received Jul 22, 

1981 under 10182-38; submitted by ICI Americas, Inc., Wilmington, Del.; 

CDL:245704-I) 

80239 Hegdal, P.L.; Blaskiewicz, R.W. (1981) Hazards to Barn Owls Associated 

with the Use of Talon^(R)I (Brodifacoum Bait) for Control- ling Rats and 

House Mice. (Unpublished study received Jul 22, 1981 under 10182-38; 

prepared in cooperation with U.S. Fish and Wildlife Service, Wildlife 

Research Center, submitted by ICI Americas, Inc., Wilmington, Del.; 

CDL:245704-J) 

80240 Morris, K.D.; Kaukeinen, D.E. (1980) Talon^(TM)I 15-day Choice Feeding of 

Blank Talon Pellets Containing Demeclocycline vs. EPA Meal Using Albino 

Norway Rats: Report Series TMUD3245/B. (Un- published study received 

Jul 22, 1981 under 10182-38; submitted by ICI Americas, Inc., Wilmington, 

Del.; CDL:245704-K) 

80241

Secondary 

Poisoning

Morris, K.D.; Kaukeinen, D.E. (1980) Talon: Rodent Baiting Sites of the Barn 

Owl: Secondary Hazard Study: Report Series TMUD3335/B. (Unpublished 

study received Jul 22, 1981 under 10182-38; sub- mitted by ICI Americas, 

Inc., Wilmington, Del.; CDL:245704-L) 

80242

46750931

J001738

Secondary 

Poisoning

Mendenhall, V.M.; Pank, L.F. (1979) Secondary Poisoning of Owls by 

Anticoagulant Rodenticides. (U.S. Fish and Wildlife Service, Patuxent 

Wildlife Research Center; unpublished study; CDL: 245704-M) 
40

80243

Secondary 

Poisoning

Marsh, R.E.; Howard, W.E. (1978) Secondary Toxicity Hazards Tests of 

Brodifacoum to Raptors. Prelim. rept. (Unpublished study received Jul 22, 

1981 under 10182-38; prepared in cooperation with Univ. of California--

Davis, Dept. of Avian Science, Raptor Center, submitted by ICI Americas, 

Inc., Wilmington, Del.; CDL:245704-N) 

80244

Secondary 

Poisoning

Savarie, P.J.; LaVoie, G.K.; Hayes, G. (1979) Secondary Toxicity Hazards 

of the Anticoagulant Brodifacoum to American Kestrals (Falco sparverius): 

Research Report Work Unit 940.16. (Unpublished study received Jul 22, 

1981 under 10182-38; prepared in cooperation with U.S. Fish and Wildlife 

Service, Denver Wildlife Research Center and Arapahoe Animal Hospital, 

submitted by ICI Americas, Inc., Wilmington, Del.; CDL:245704-O) 

80249

InvalidatedSecondary 

Poisoning

Morris, K.D.; Kaukeinen, D.E.; Brooks, C.; et al. (1978) Talon^(TM)I: 

Secondary Toxicity of Brodifacoum to Dogs (Bea- gles): Report Series 

TMUD1997/B. Rev. (Unpublished study re- ceived Jul 22, 1981 under 

10182-38; submitted by ICI Americas, Inc., Wilmington, Del.; CDL:245704-

U) 

84346

Repellency trials

Morris, K.D.; Kaukeinen, D.E. (1981) Volid: Effect of Candidate Avian 

Repellent Agents on Laboratory Acceptance of Blank Volid Pellets to Pine 

Voles: Report Series TMUD3591/B. (Unpublished study received Sep 10, 

1981 under 10182-58; submitted by ICI Americas, Inc., Wilmington, Del.; 

CDL:245924-G) 

84347 Morris, K.D.; Kaukeinen, D.E. (1981) Volid: Effect of Candidate Avian 

Repellent Agents on Laboratory Acceptance of Blank Volid Pellets to 

Meadow Voles: Report Series TMUD3592/B. (Unpublished study received 

Sep 10, 1981 under 10182-58; submitted by ICI Americas, Inc., Wilmington, 

Del.; CDL:245924-H) 

84348 Morris, K.D.; Kaukeinen, D.E. (1981) Volid: Effect of Candidate Avian 

Repellent Agents on Laboratory Group Acceptance of Blank Volid Pellets to 

Pigeons: Report Series TMUD3593/B. (Unpub- lished study received Sep 

10, 1981 under 10182-58; submitted by ICI Americas, Inc., Wilmington, Del.; 

CDL:245924-I) 

84349 Kaukeinen, D.E.; Jackson, W.B. (1981) Volid: Effect of Potential Avian 

Aversive Agents on Wild Pigeons: Report Series TMUD3682/B.

(Unpublished study received Sep 10, 1981 under 10182-58; pre- pared in 

cooperation with Bowling Green State Univ., Environ- mentl Studies Center, 

submitted by ICI Americas, Inc., Wilming- ton, Del.; CDL:245924-J) 

84350 Morris, K.D.; Kaukeinen, D.E. (1981) Volid^(TM)I: Acceptability of 50 ppm 

Volid Pellets Containing 5% Graphite versus Blank, Undyed Volid Pellets 

Using Wild Meadow Voles: Report Series TMUD3658/B. (Unpublished study 

received Sep 10, 1981 under 10182-58; submitted by ICI Americas, Inc., 

Wilmington, Del.; CDL:245924-K) 

84351 Morris, K.D.; Kaukeinen, D.E. (1980) Volak: Three-day Choice Feeding of 

50 ppm Volak Pellets Containing 5% Graphite versus ?~Microtus~Challenge 

Diet Using Pine Voles: Report Series TMUD-3107/B. (Unpublished study 

received Sep 10, 1981 under 10182- 58; submitted by ICI Americas, Inc., 

Wilmington, Del.; CDL: 245924-L) 

84352 Morris, K.D.; Kaukeinen, D.E. (1981) Volid: Acceptance of 50 ppm Volid 

Pellets Containing 5% Graphite versus Blank, Undyed Volid Pellets Using 

Pigeons: Report Series TMUD3594/B. (Unpublished study received Sep 10, 
41

1981 under 10182-58; submitted by ICI Americas, Inc., Wilmington, Del.; 

CDL:245924-M) 

84353 Morris, K.D.; Kaukeinen, D.E. (1981) Volid: Acceptability of 50 ppm Volid 

Pellets Containing 5% Graphite versus 50 ppm Volid Pellets Containing 50 

ppm Rhodamine B Using Ring-necked Pheas- ants: Report Series 

TMUD3595/B. (Unpublished study received Sep 10, 1981 under 10182-58; 

submitted by ICI Americas, Inc., Wilmington, Del.; CDL:245924-N) 

84354 Morris, K.D.; Kaukeinen, D.E. (1981) Volid: Acceptability of 50 ppm Volid 

Pellets Containing 5% Graphite versus Blank, Un- dyed Volid Pellets Using 

Pigeons: Report Series TMUD3659/B. (Unpublished study received Sep 10, 

1981 under 10182-58; sub- mitted by ICI Americas, Inc., Wilmington, Del.; 

CDL:245924-O) 

84355

Invalidated

Morris, K.D.; Kaukeinen, D.E. (1981) Volid^(TM)I: Acceptability of 10 ppm 

Volid Pellets Containing 5% Graphite vs 50 ppm Volid Pellets Containing 50 

ppm Rodamine B Using Ring-necked Pheas- ants: Report Series 

TMUD3625/B. (Unpublished study received Sep 10, 1981 under 10182-58; 

submitted by ICI Americas, Inc., Wilmington, Del.; CDL:245924-P) 

84356 Kaukeinen, D.E.; Byers, R.; Merson, M.; et al. (1981) Volid^(TM)I: Efficacy to 

Meadow Voles and Wildlife Hazard from Broadcast Application of 10 ppm 

Pellets at 20.4 lb/A (22.9 kg/ha) in a Dormant Apple Orchard: Report Series 

TMUD3683/B. (Unpublished study received Sep 10, 1981 under 10182-58; 

prepared in coopera- tion with Virginia Polytechnic Institute, Winchester Fruit 

Re- search Laboratory, submitted by ICI Americas, Inc., Wilmington, Del.; 

CDL:245924-Q) 

84357 Merson, M.H.; Byers, R.E. (1981) A Study of Nontarget Species Hazard of 

Brodifacoum Use as an Orchard Rodenticide. (Unpub- lished study received 

Sep 10, 1981 under 10182-58; prepared by Virginia Polytechnic Institute 

and State Univ., Winchester Fruit Research Laboratory, submitted by ICI 

Americas, Inc., Wilmington, Del.; CDL:245924-R) 

85726 Kaukeinen, D.E.; Ussary, J.P.; Koubek, K.G.; et al. (1981) Brodi- facoum 

Residues in Meadow Voles and Other Wildlife from a 10 ppm Volid~(TM)~ 

Treated Orchard--Trial 24VA81-001: Report Series TMU0660/B. 

(Unpublished study received Jul 22, 1981 under 10182-EX-21; submitted by 

ICI Americas, Inc., Wilmington, Del.; CDL:245702-D) 

85729 Dickie, B.C.; Balk, M.W.; Rao, G.N.; et al. (1980) Palatability of a 

Rodenticide Base in Dogs: Raltech Study No. 80527. Final rept. 

(Unpublished study received Jul 22, 1981 under 10182-38; prepared by 

Ralston Purina Co., submitted by ICI Americas, Inc., Wilmington, Del.; 

CDL:245704-T) 

94694or

46750931 or 

40077202 

Supplemental

Mendenhall, V.M.; Pank, L.F. (1980) Secondary poisoning of owls by 

anticoagulant rodenticides. Wildlife Society Bulletin 8(4):311- 315. 

(Also~In~unpublished submission received Feb 7, 1982 under 12455-34; 

submitted by Bell Laboratories, Madison, Wis.; CDL: 246741-C) 

128238

Summary of 

Toxicity Data

ICI Americas, Inc. (1983) Volid Rodenticide Pellets (Containing 

Brodifacoum) for Control of Microtus in Orchards: ?Summary of Toxicity 

Data|. (Unpublished study received Apr 29, 1983 under 10182-58; submitted 

by ICI Americas, Inc., Wilmington, DE; CDL:250077-A) 

128239

invalidated

Merson, M. (1983) Rodenticide Application and Vole Population Estimation 

in 1981: Secondary Poisoning Study. (Unpublished study received Apr 29, 
42

1983 under 10182-58; submitted by ICI Americas, Inc., Wilmington, DE; 

CDL:250077-E) 

128240

Supplemental

Secondary 

toxicity

Hegdal, P.; Colvin, B.; Blaskiewicz, R.; et al. (1983) Secondary Hazards to 

Screech Owls Associated with the Use of Volid--Brodi- facoum Bait for 

Controlling Voles in Orchards. (Unpublished study received Apr 29, 1983 

under 10182-58; prepared by U.S. Fish and Wildlife Service, Wildlife 

Research Center, submitted by ICI Americas, Inc., Wilmington, DE; 

CDL:250077-G) 

128421 Morris, K.; Kaukeinen, D.; Brooks, C.; et al. (1978) Talon: Second- ary 

Toxicity of Brodifacoum to Dogs (Beagles): Report Series TMUD1997/B. 

Rev. (Unpublished study received Aug 15, 1978 un- der 10182-26; 

submitted by ICI Americas, Inc., Wilmington, DE; CDL:234658-B) 

128422

Supplemental

Secondary 

toxicity

Morris, K.; Kaukeinen, D.; Brooks, C.; et al. (1978) Talon: Second- ary 

Toxicity of Brodifacoum to Foxes: Report Series TMUD1998/B.

(Unpublished study received Aug 15, 1978 under 10182-26; submit- ted by 

ICI Americas, Inc., Wilmington, DE; CDL:234658-C) 

139519

Invalidated

Kaukeinen, D.; Byers, R. (1981) Volak: Potential Hazard of the 10 ppm 

Black Pellet Broadcast at 3 Rates As Indicated by Penned Ring-necked 

Pheasants: Report Series TMUD3512/B. (Unpublished study received Apr 

29, 1983 under 10182-58; submitted by ICI Americas, Inc., Wilmington, DE; 

CDL:250077-D) 

139520

invalidated

Kaukeinen, D.; Ussary, J.; Peterson, F. (1983) Brodifacoum Residues in 

Screech Owls and Other Wildlife from Volid-treated Apple Orchards: Report 

Series TMU0910/B. (Unpublished study received Apr 29, 1983 under 10182-

58; submitted by ICI Americas, Inc., Wilmington, DE; CDL:250077-F) 

152102

Acceptable

Edwards, P.; Swaine, H. (1983) Brodifacoum: Hazard to Non-target Animals 

from the Use of 'Klerat' Bait on Farms in the UK for Control of the Common 

Rat Rattus norvegicus: Report No. RJ0305B. Unpublished study prepared 

by ICI Plant Protection Division. 36 p. 

152103

Supplemental

Edwards, P.; Swaine, H.; Kennedy, S. (1984) Brodifacoum: Hazard to Nontarget Animals from 'Pulsed' Baiting with 'Klerat' Pelleted Bait around Farm 

Buildings: Report No. RJ0369B. Unpublished study prepared by ICI Plant 

Protection Division. 61 p. 

152104

Supplemental

Edwards, P.; Swaine, H.; Coulson, J.; et al. (1984) Brodifacoum: Hazard to 

Non-target Animals from 'Pulsed' Baiting with Wax Block Baits around Farm 

Buildings: Report No. RJ0375B. Unpub- lished study prepared by ICI Plant 

Protection Division. 64 p. 

161693 Hegdal, P.; Colvin, B.; Blaskiewicz, R.; et al. (1983) Secondary Hazards to 

Screech Owls Associated with the Use of Volid (Brodi- facoum Bait) for 

Controlling Voles in Orchards. Unpublished study prepared by U.S. Fish and 

Wildlife Service, Wildlife Re- search Center. 110 p. 

163158 ICI Americas Inc. (19??) Brodifacoum: Mode of Action and Antidote Studies. 

Unpublished compilation. 19 p. 

46360601 

Probabilistic 

Assessment

Giddings, J.; Warren-Hicks, W. (2004) A Probabilistic Assessment of the 

Risk of Brodifacoum to Non-target Predators and Scavengers. Project 

Number: T001270/04. Unpublished study prepared by the Cadmus Group, 

Inc. 114 p.
43

47114602 EPA 

Paper

Erickson, W.; Urban, D. (2004) Potential Risk of Nine Rodenticides to Birds 

and Nontarget Mammals: A Comparative Approach. Prepared by US EPA, 

OPP, EFED, Environmental Risk Branch. pp. 81-85.

47668004 Veitch, C.; Clout, M. (2002) The Eradication of Alien Mammals from Five 

Offshore Islands, Mauritius, Indian Ocean. Turning the Tide: The Eradication 

of Invasive Species. IUCN SSC Invasive Species Specialist Group. IUCN, 

Gland, Switzerland and Cambridge, UK: 40-45.

47668005 Veitch, C.; Clout, M. (2002) Eradication of Rabbits and Mice from 

Subantarctic Enderby and Rose Island . Turning the Tide: The Eradication of 

Invasive Species. IUCN SSC Invasive Species Specialist Group. IUCN, 

Gland, Switzerland and Cambridge, UK: 319-328.

48396204 

Efficacy –

open lit

Byers, R. (1981) Pine Vole Control with Anticoagulant Baits in Apple 

Orchards (Diphacinone, Chlorophacinone, Bromadiolone, and Brodifacoum). 

Journal of the American Society of Horticultural Science 106(1): 101-105.

48396205

Efficacy –

open lit

Byers, R. (1979) Meadow Vole Control Using Anticoagulant Baits 

(Diphacinone, Chlorophacinone, and Brodifacoum). HortScience 14(1): 44-

45.

80237 

bioaccumulation

ICI Americas Inc., (1981) Agricultural Chemicals Division, Research and 

Development Dept. Report Series TMU 0545/B, Dec. 17, 1980 Acc. 

#245704 Brodifacoum Residues in Rodents, Pheasants and Ground Rat 

Tissues

48435601-

48435607

2005-2011 Buckelew, S.; Howald, G.; Alifano, A, Wegmann,A, Eisemann, J.; 

et al. Palmyra Atoll Rat Eradication Assessment, Monitoring, and Methods.

ACC 225704 

SupplementalHED review?

Brodifacoum: Absorption, excretion and tissue retention

i n the rat, by H. Bratt, & Pamela Hundson for I C I , LTD, Alderly Park, 

Macclesfield, Cheshire, UK CTL Study No. URO110, Report No. -

CTL/P/468,

ACC 250077

Invalidated

Morris, K.D. (1983) Analysis of Screech Owl Mortality as Revealed by 

Banding Studies. ICI Americas, Inc., Acc#250077.

Merson, M.H. 1984. Residues of the Rodenticide Brodifacoum in Voles and 

Raptors After Orchard Treatment. J. Wildl. Manage., Vol 48, No. 1, pp. 212-

216

Acc. #250077

open lit

Van Camp, Laurel F . , & Charles J. Henny (1975). The Screech Owl: Its L i f 

e H i s t o r y and P o p u l a t i o n Ecology i n Northern Ohio. USDI, FWS, 

North American Fauna, Nurnbeg 71 p u b l i s h e d by USFWS . 63 pp. 

J001730 = PDF 

copy

Hegdal PL, Colvin BA (1988) Potential hazard to eastern screech owls

and other raptors of brodifacoum bait used for vole control in orchards. 

Environ Toxicol Chem 7:245–260

J007888 = PDF 

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Joermann, G . 1998. A Review of secondary-poisoning studies with 

rodenticides. Bulletin OEPP/EPPO #26 pp 157-176

E151555 = PDF 

copy

Vandenbroucke, V. , 2008. Pharmacokinetics of Eight anticoagulant 

rodenticides in mice after single oral administration

J000317 = PDF 

copy

Stone, W. B., J. C. Okonlewski, and J. R. Stedelin 1999. Poisoning of 

Wildlife with Anticoagulant Rodenticides in New York. Journal of Wildlife 

Diseases 35(2) 187-193
44

J001732 = PDF 

copy 

Birks, J. D. S. , 1998. Secondary Rodenticide Poisoning Risk Arising From 

Winter Farmyard Use by the European Polecat Mustela putorius. Biological 

Conservation, Vol. 85, pp. 233-240

J001920 = PDF 

copy

Hegdal, P. L., T. A. Gatz, and E. C. Fite. 1980. 

Secondary Effects of Rodenticides On Mammalian Predators
45

Appendix B. EPI Suite v.4.1 Output File for Brodifacoum

CAS Number: 056073-10-0

SMILES : c1cc(Br)ccc1c(cc2)ccc2C3Cc4ccccc4C(C5=C(O)c6ccccc6OC5(=O))C3

CHEM : Brodifacoum

MOL FOR: C31 H23 Br1 O3 

MOL WT : 523.43

------------------------------ EPI SUMMARY (v4.10) -------------------------- Physical Property Inputs:

 Log Kow (octanol-water): 8.50 Boiling Point (deg C) : ------ Melting Point (deg C) : 230.00 Vapor Pressure (mm Hg) : ------ Water Solubility (mg/L): 0.0038 Henry LC (atm-m3/mole) : ------

KOWWIN Program (v1.68) Results:

===============================

 Log Kow(version 1.68 estimate): 8.51

Experimental Database Structure Match:

 Name : Brodifacoum

 CAS Num : 056073-10-0

 Exp Log P: 8.50 

 Exp Ref : TOMLIN,C (1997) 

SMILES : c1cc(Br)ccc1c(cc2)ccc2C3Cc4ccccc4C(C5=C(O)c6ccccc6OC5(=O))C3

CHEM : Brodifacoum

MOL FOR: C31 H23 Br1 O3 

MOL WT : 523.43

-------+-----+--------------------------------------------+---------+--------

TYPE | NUM | LOGKOW FRAGMENT DESCRIPTION | COEFF | VALUE 

-------+-----+--------------------------------------------+---------+--------

Frag | 2 | -CH2- [aliphatic carbon] | 0.4911 | 0.9822

Frag | 2 | -CH [aliphatic carbon] | 0.3614 | 0.7228

Frag | 2 | =CH- or =C< [olefinc carbon] | 0.3836 | 0.7672

Frag | 24 | Aromatic Carbon | 0.2940 | 7.0560

Frag | 1 | -Br [bromine, aromatic attach] | 0.8900 | 0.8900

Frag | 1 | -C(=O)O [ester, aliphatic attach] |-0.9505 | -0.9505

Frag | 1 | -OH [alcohol, olefinic attach] |-0.8855 | -0.8855

Factor| 1 | Cyclic ester [olefinic type] correction |-0.2969 | -0.2969

Const | | Equation Constant | | 0.2290

-------+-----+--------------------------------------------+---------+--------

 Log Kow = 8.5143

MPBPVP (v1.43) Program Results:

===============================

Experimental Database Structure Match:

 Name : Brodifacoum

 CAS Num : 056073-10-0

 Exp MP (deg C): 230 

 Exp BP (deg C): ---

 Exp VP (mm Hg): ---

SMILES : c1cc(Br)ccc1c(cc2)ccc2C3Cc4ccccc4C(C5=C(O)c6ccccc6OC5(=O))C3

CHEM : Brodifacoum

MOL FOR: C31 H23 Br1 O3 

MOL WT : 523.43

------------------------ SUMMARY MPBVP v1.43 --------------------

Boiling Point: 691.46 deg C (Adapted Stein and Brown Method)

Melting Point: 349.84 deg C (Adapted Joback Method)

Melting Point: 290.08 deg C (Gold and Ogle Method)

Mean Melt Pt : 319.96 deg C (Joback; Gold,Ogle Methods)

 Selected MP: 302.03 deg C (Weighted Value)
46

Vapor Pressure Estimations (25 deg C):

 (Using BP: 691.46 deg C (estimated))

 (Using MP: 230.00 deg C (user entered))

 VP: 6.64E-027 mm Hg (Antoine Method)

 : 8.85E-025 Pa (Antoine Method)

 VP: 1.11E-018 mm Hg (Modified Grain Method)

 : 1.48E-016 Pa (Modified Grain Method)

 VP: 5.46E-015 mm Hg (Mackay Method)

 : 7.28E-013 Pa (Mackay Method)

 Selected VP: 1.11E-018 mm Hg (Modified Grain Method)

 : 1.48E-016 Pa (Modified Grain Method)

 Subcooled liquid VP: 1.77E-016 mm Hg (25 deg C, Mod-Grain method)

 : 2.36E-014 Pa (25 deg C, Mod-Grain method)

-------+-----+--------------------+----------+---------

TYPE | NUM | BOIL DESCRIPTION | COEFF | VALUE 

-------+-----+--------------------+----------+---------

Group | 2 | -CH2- (ring) | 26.44 | 52.88

Group | 2 | >CH- (ring) | 21.66 | 43.32

Group | 2 | =C< (ring) | 28.19 | 56.38

Group | 1 | -OH (alcohol) | 106.27 | 106.27

Group | 16 | CH (aromatic) | 28.53 | 456.48

Group | 6 | -C (aromatic) | 30.76 | 184.56

Group | 2 | C (3a aromatic) | 45.46 | 90.92

Group | 1 | -COO- (ring) | 172.49 | 172.49

Group | 1 | -Br (to aromat) | 61.85 | 61.85

 * | | Equation Constant | | 198.18

=============+====================+==========+=========

RESULT-uncorr| BOILING POINT in deg Kelvin | 1423.33

RESULT- corr | BOILING POINT in deg Kelvin | 964.62

 | BOILING POINT in deg C | 691.46

-------------------------------------------------------

-------+-----+--------------------+----------+---------

TYPE | NUM | MELT DESCRIPTION | COEFF | VALUE 

-------+-----+--------------------+----------+---------

Group | 2 | -CH2- (ring) | 7.75 | 15.50

Group | 2 | >CH- (ring) | 19.88 | 39.76

Group | 2 | =C< (ring) | 37.02 | 74.04

Group | 1 | -OH (alcohol) | 44.45 | 44.45

Group | 16 | CH (aromatic) | 8.13 | 130.08

Group | 6 | -C (aromatic) | 37.02 | 222.12

Group | 2 | C (3a aromatic) | 37.02 | 74.04

Group | 1 | -COO- (ring) | 53.60 | 53.60

Group | 1 | -Br (to aromat) | 43.43 | 43.43

 * | | Equation Constant | | 122.50

=============+====================+==========+=========

 RESULT | MELTING POINT in deg Kelvin | 819.52

RESULT-limit| MELTING POINT in deg Kelvin | 623.00

 | MELTING POINT in deg C | 349.84

-------------------------------------------------------

Water Sol from Kow (WSKOW v1.42) Results:

========================================

 Water Sol: 5.276e-006 mg/L

Experimental Water Solubility Database Match:

 Name : Brodifacoum

 CAS Num : 056073-10-0

 Exp WSol : 0.0038 mg/L (20 deg C)

 Exp Ref : TOMLIN,C (1997); pH 5.2 

SMILES : c1cc(Br)ccc1c(cc2)ccc2C3Cc4ccccc4C(C5=C(O)c6ccccc6OC5(=O))C3

CHEM : Brodifacoum

MOL FOR: C31 H23 Br1 O3 

MOL WT : 523.43

---------------------------------- WSKOW v1.42 Results ------------------------

Log Kow (estimated) : 8.51 
47

Log Kow (experimental): 8.50 

 Cas No: 056073-10-0

 Name : Brodifacoum

 Refer : TOMLIN,C (1997)

Log Kow used by Water solubility estimates: 8.50 (user entered)

Equation Used to Make Water Sol estimate:

 Log S (mol/L) = 0.693-0.96 log Kow-0.0092(Tm-25)-0.00314 MW + Correction

 Melting Pt (Tm) = 230.00 deg C (Use Tm = 25 for all liquids)

 Correction(s): Value

 -------------------- -----

 No Applicable Correction Factors

 Log Water Solubility (in moles/L) : -10.997

 Water Solubility at 25 deg C (mg/L): 5.276e-006

WATERNT Program (v1.01) Results:

===============================

 Water Sol (v1.01 est): 6.8599e-007 mg/L

Experimental Water Solubility Database Match:

 Name : Brodifacoum

 CAS Num : 056073-10-0

 Exp WSol : 0.0038 mg/L (20 deg C)

 Exp Ref : TOMLIN,C (1997); pH 5.2 

SMILES : c1cc(Br)ccc1c(cc2)ccc2C3Cc4ccccc4C(C5=C(O)c6ccccc6OC5(=O))C3

CHEM : Brodifacoum

MOL FOR: C31 H23 Br1 O3 

MOL WT : 523.43

-------+-----+--------------------------------------------+----------+---------

TYPE | NUM | WATER SOLUBILITY FRAGMENT DESCRIPTION | COEFF | VALUE 

-------+-----+--------------------------------------------+----------+---------

Frag | 2 | -CH [aliphatic carbon] |-0.5285 | -1.0570

Frag | 2 | =CH- or =C< [olefinc carbon] |-0.3646 | -0.7292

Frag | 16 | Aromatic Carbon (C-H type) |-0.3359 | -5.3738

Frag | 1 | -Br [bromine, aromatic attach] |-0.5661 | -0.5661

Frag | 1 | -C(=O)O [ester, aliphatic attach] | 0.5757 | 0.5757

Frag | 8 | Aromatic Carbon (C-substituent type) |-0.5400 | -4.3196

Frag | 2 | -CH2- [aliphatic carbon, cyclic] |-0.3308 | -0.6617

Frag | 1 | -OH [alcohol, olefinic attach] | 0.0000 | 0.0000

Const | | Equation Constant | | 0.2492

-------+-----+--------------------------------------------+----------+---------

 Log Water Sol (moles/L) at 25 dec C = -11.8825

Water Solubility (mg/L) at 25 dec C =6.8599e-007

ECOSAR Program (v1.00) Results:

==============================

SMILES : c1cc(Br)ccc1c(cc2)ccc2C3Cc4ccccc4C(C5=C(O)c6ccccc6OC5(=O))C3

CHEM : Brodifacoum

CAS Num: 

ChemID1: 

ChemID2: 

ChemID3: 

MOL FOR: C31 H23 Br1 O3 

MOL WT : 523.43

Log Kow: 8.51 (KowWin estimate)

Melt Pt: 230.00 deg C

Wat Sol: 0.0038 mg/L (measured)

ECOSAR v1.00 Class(es) Found

------------------------------

Acrylates

Vinyl/Allyl Alcohols

 Predicted
48

ECOSAR Class Organism Duration End Pt mg/L (ppm)

=========================== ================== ======== ====== ==========

Acrylates : Fish 96-hr LC50 0.196 *

Acrylates : Daphnid 48-hr LC50 0.158 *

Acrylates : Green Algae 96-hr EC50 0.821 *

Acrylates : Fish 30-day ChV 0.000247

Acrylates : Daphnid ChV 0.000599 !

Acrylates : Green Algae ChV 0.062 *

Acrylates : Fish (SW) 96-hr LC50 0.217 *

Acrylates : Mysid Shrimp (SW) 96-hr LC50 0.006 *

Acrylates : Fish (SW) ChV 0.007 *!

Acrylates : Mysid Shrimp (SW) ChV 1.51e-007 !

Vinyl/Allyl Alcohols : Fish 96-hr LC50 1.735 *

Vinyl/Allyl Alcohols : Daphnid 48-hr LC50 0.527 *

Vinyl/Allyl Alcohols : Green Algae 96-hr EC50 0.035 *

Vinyl/Allyl Alcohols : Fish ChV 0.000159 !

Vinyl/Allyl Alcohols : Daphnid ChV 0.000755 !

Vinyl/Allyl Alcohols : Green Algae ChV 0.022 *

=========================== ================== ======== ====== ==========

Neutral Organic SAR : Fish 96-hr LC50 0.00124

(Baseline Toxicity) : Daphnid 48-hr LC50 0.00157

 : Green Algae 96-hr EC50 0.010 *

 : Fish ChV 0.000102

: Daphnid ChV 0.000459

: Green Algae ChV 0.012 *

Note: * = asterisk designates: Chemical may not be soluble

 enough to measure this predicted effect.

Note: ! = exclamation designates: The toxicity value was determined from

 a predicted SAR using established acute-to-chronic ratios and ECOSAR

 regression techniques which are documented in the supporting Technical

 Reference Manual. When possible, this toxicity value should be

 considered in a weight of evidence approach.

Acrylates:

---------

 For Fish, Daphnid and Mysid Shrimp Acute Toxicity Values: If the log Kow

of the chemical is greater than 5.0, or if the compound is solid and the LC50

exceeds the water solubility by 10X, no effects at saturation are predicted

for these endpoints.

 For Green Algae Acute Toxicity Values: If the log Kow of the chemical is

greater than 6.4, or if the compound is solid and the EC50 exceeds the water

solubility by 10X, no effects at saturation are predicted for these endpoints.

 For All Chronic Toxicity Values: If the log Kow of the chemical is greater

than 8.0, or if the compound is solid and the ChV exceeds the water solubility

by 10X, no effects at saturation are predicted for these endpoints.

ECOSAR v1.00 SAR Limitations:

----------------------------

Maximum LogKow: 5.0 (LC50)

Maximum LogKow: 6.4 (EC50)

Maximum LogKow: 8.0 (ChV)

Maximum Mol Wt: 1000

Vinyl/Allyl Alcohols:

--------------------

 For Fish and Daphnid Acute Toxicity Values: If the log Kow of the chemical

is greater than 5.0, or if the compound is solid and the LC50 exceeds the

water solubility by 10X, no effects at saturation are predicted for these

endpoints.

 For Green Algae Acute Toxicity Values: If the log Kow of the chemical is

greater than 6.4, or if the compound is solid and the EC50 exceeds the water

solubility by 10X, no effects at saturation are predicted for these endpoints.

 For All Chronic Toxicity Values: If the log Kow of the chemical is greater

than 8.0, or if the compound is solid and the ChV exceeds the water solubility
49

by 10X, no effects at saturation are predicted for these endpoints.

ECOSAR v1.00 SAR Limitations:

----------------------------

Maximum LogKow: 5.0 (LC50)

Maximum LogKow: 6.4 (EC50)

Maximum LogKow: 8.0 (ChV)

Maximum Mol Wt: 1000

Baseline Toxicity SAR Limitations:

---------------------------------

Maximum LogKow: 5.0 (Fish 96-hr LC50; Daphnid LC50)

Maximum LogKow: 6.4 (Green Algae EC50)

Maximum LogKow: 8.0 (ChV)

Maximum Mol Wt: 1000

HENRYWIN (v3.20) Program Results:

=============================

 Bond Est : 5.40E-013 atm-m3/mole (5.47E-008 Pa-m3/mole)

 Group Est: Incomplete

SMILES : c1cc(Br)ccc1c(cc2)ccc2C3Cc4ccccc4C(C5=C(O)c6ccccc6OC5(=O))C3

CHEM : Brodifacoum

MOL FOR: C31 H23 Br1 O3 

MOL WT : 523.43

--------------------------- HENRYWIN v3.20 Results --------------------------

----------+---------------------------------------------+---------+----------

 CLASS | BOND CONTRIBUTION DESCRIPTION | COMMENT | VALUE

----------+---------------------------------------------+---------+----------

HYDROGEN | 6 Hydrogen to Carbon (aliphatic) Bonds | | -0.7181

HYDROGEN | 16 Hydrogen to Carbon (aromatic) Bonds | | -2.4687

HYDROGEN | 1 Hydrogen to Oxygen Bonds | | 3.2318

FRAGMENT | 3 C-C | | 0.3489

FRAGMENT | 3 C-Car | | 0.4858

FRAGMENT | 1 C-Cd | | 0.0635

FRAGMENT | 24 Car-Car | | 6.3314

FRAGMENT | 1 Car-Br | | 0.2454

FRAGMENT | 1 Cd-CO | | 1.9260

FRAGMENT | 1 CO-O | | 0.0714

FRAGMENT | 1 Car-Car Ring-to-Ring (biphenyl-type) | | 0.1490

FRAGMENT | 1 Cd-O | | 0.2051

FRAGMENT | 1 Car-Cd | | 0.4371

FRAGMENT | 1 Car-O | | 0.3473

FRAGMENT | 1 Cd=Cd | | 0.0000

----------+---------------------------------------------+---------+----------

RESULT | BOND ESTIMATION METHOD for LWAPC VALUE | TOTAL | 10.656

----------+---------------------------------------------+---------+----------

HENRYs LAW CONSTANT at 25 deg C = 5.40E-013 atm-m3/mole

 = 2.21E-011 unitless

= 5.47E-008 Pa-m3/mole

--------+-----------------------------------------------+------------+--------

 | GROUP CONTRIBUTION DESCRIPTION | COMMENT | VALUE 

--------+-----------------------------------------------+------------+--------

 | 1 Cd (C)(CO) | ESTIMATE | 0.10

 | 1 CH2 (C)(C) | | -0.15

 | 1 CH2 (C)(Car) | | -0.19

 | 1 CH (C)(C)(Car) | | 0.29

 | 16 Car-H (Car)(Car) | | 1.76

 | 3 Car (C)(Car)(Car) | | 2.10

 | 2 Car (Car)(Car)(Car) external | ESTIMATE | 0.66

 | 1 Car (Car)(Car)(Br) | | 0.49

 | 1 Car (Car)(Car)(O) | | -0.43

 | 1 CO (Cd)(O) | ESTIMATE | 4.00

 | 1 Car (Car)(Car)(Cd) | ESTIMATE | 0.75

 | MISSING Value for: CH (C)(Cd)(Car)

 | MISSING Value for: Cd (O)(Car)
50

 | MISSING Value for: O-H (Cd)

 | MISSING Value for: O (CO)(Car)

--------+-----------------------------------------------+------------+--------

RESULT | GROUP ESTIMATION METHOD for LOG GAMMA VALUE | INCOMPLETE | 9.38

--------+-----------------------------------------------+------------+--------

For Henry LC Comparison Purposes:

 Exper Database: none available

 User-Entered Henry LC: not entered

 Henrys LC [via VP/WSol estimate using User-Entered or Estimated values]:

 HLC: 2.012E-016 atm-m3/mole (2.038E-011 Pa-m3/mole)

 VP: 1.11E-018 mm Hg (source: MPBPVP)

 WS: 0.0038 mg/L (source: User-Entered)

Log Octanol-Air (KOAWIN v1.10) Results:

======================================

 Log Koa: 19.156

SMILES : c1cc(Br)ccc1c(cc2)ccc2C3Cc4ccccc4C(C5=C(O)c6ccccc6OC5(=O))C3

CHEM : Brodifacoum

MOL FOR: C31 H23 Br1 O3 

MOL WT : 523.43

--------------------------- KOAWIN v1.10 Results --------------------------

Log Koa (octanol/air) estimate: 19.156

 Koa (octanol/air) estimate: 1.432e+019

Using:

 Log Kow: 8.50 (user entered)

 HenryLC: 5.4e-013 atm-m3/mole (HenryWin est)

 Log Kaw: -10.656 (air/water part.coef.)

LogKow : 8.50 (exp database)

LogKow : 8.51 (KowWin estimate)

Henry LC: --- atm-m3/mole(exp database)

Henry LC: 5.4e-013 atm-m3/mole (HenryWin bond estimate)

Log Koa (octanol/air) estimate: 19.166 (from KowWin/HenryWin)

BIOWIN (v4.10) Program Results:

==============================

SMILES : c1cc(Br)ccc1c(cc2)ccc2C3Cc4ccccc4C(C5=C(O)c6ccccc6OC5(=O))C3

CHEM : Brodifacoum

MOL FOR: C31 H23 Br1 O3 

MOL WT : 523.43

--------------------------- BIOWIN v4.10 Results ----------------------------

 Biowin1 (Linear Model Prediction) : Biodegrades Fast

 Biowin2 (Non-Linear Model Prediction): Biodegrades Fast

 Biowin3 (Ultimate Biodegradation Timeframe): Months

 Biowin4 (Primary Biodegradation Timeframe): Weeks

 Biowin5 (MITI Linear Model Prediction) : Does Not Biodegrade Fast

 Biowin6 (MITI Non-Linear Model Prediction): Does Not Biodegrade Fast

 Biowin7 (Anaerobic Model Prediction): Does Not Biodegrade Fast

 Ready Biodegradability Prediction: NO

------+-----+--------------------------------------------+---------+---------

TYPE | NUM | Biowin1 FRAGMENT DESCRIPTION | COEFF | VALUE 

------+-----+--------------------------------------------+---------+---------

Frag | 1 | Aliphatic alcohol [-OH] | 0.1587 | 0.1587

Frag | 1 | Ester [-C(=O)-O-C] | 0.1742 | 0.1742

Frag | 1 | Aromatic bromide [-Br] | -0.1103 | -0.1103

Frag | 3 | Alkyl substituent on aromatic ring | 0.0547 | 0.1640

MolWt| * | Molecular Weight Parameter | | -0.2492

Const| * | Equation Constant | | 0.7475

============+============================================+=========+=========

 RESULT | Biowin1 (Linear Biodeg Probability) | | 0.8849
51

============+============================================+=========+=========

------+-----+--------------------------------------------+---------+---------

TYPE | NUM | Biowin2 FRAGMENT DESCRIPTION | COEFF | VALUE 

------+-----+--------------------------------------------+---------+---------

Frag | 1 | Aliphatic alcohol [-OH] | 1.1178 | 1.1178

Frag | 1 | Ester [-C(=O)-O-C] | 4.0795 | 4.0795

Frag | 1 | Aromatic bromide [-Br] | -1.6779 | -1.6779

Frag | 3 | Alkyl substituent on aromatic ring | 0.5771 | 1.7313

MolWt| * | Molecular Weight Parameter | | -7.4327

============+============================================+=========+=========

 RESULT | Biowin2 (Non-Linear Biodeg Probability) | | 0.6957

============+============================================+=========+=========

A Probability Greater Than or Equal to 0.5 indicates --> Biodegrades Fast

A Probability Less Than 0.5 indicates --> Does NOT Biodegrade Fast

------+-----+--------------------------------------------+---------+---------

TYPE | NUM | Biowin3 FRAGMENT DESCRIPTION | COEFF | VALUE 

------+-----+--------------------------------------------+---------+---------

Frag | 1 | Aliphatic alcohol [-OH] | 0.1600 | 0.1600

Frag | 1 | Ester [-C(=O)-O-C] | 0.1402 | 0.1402

Frag | 1 | Aromatic bromide [-Br] | -0.1360 | -0.1360

Frag | 3 | Alkyl substituent on aromatic ring | -0.0749 | -0.2246

MolWt| * | Molecular Weight Parameter | | -1.1567

Const| * | Equation Constant | | 3.1992

============+============================================+=========+=========

 RESULT | Biowin3 (Survey Model - Ultimate Biodeg) | | 1.9821

============+============================================+=========+=========

------+-----+--------------------------------------------+---------+---------

TYPE | NUM | Biowin4 FRAGMENT DESCRIPTION | COEFF | VALUE 

------+-----+--------------------------------------------+---------+---------

Frag | 1 | Aliphatic alcohol [-OH] | 0.1294 | 0.1294

Frag | 1 | Ester [-C(=O)-O-C] | 0.2290 | 0.2290

Frag | 1 | Aromatic bromide [-Br] | -0.1535 | -0.1535

Frag | 3 | Alkyl substituent on aromatic ring | -0.0685 | -0.2056

MolWt| * | Molecular Weight Parameter | | -0.7552

Const| * | Equation Constant | | 3.8477

============+============================================+=========+=========

 RESULT | Biowin4 (Survey Model - Primary Biodeg) | | 3.0919

============+============================================+=========+=========

Result Classification: 5.00 -> hours 4.00 -> days 3.00 -> weeks

 (Primary & Ultimate) 2.00 -> months 1.00 -> longer

------+-----+--------------------------------------------+---------+---------

TYPE | NUM | Biowin5 FRAGMENT DESCRIPTION | COEFF | VALUE 

------+-----+--------------------------------------------+---------+---------

Frag | 1 | Aliphatic alcohol [-OH] | 0.1611 | 0.1611

Frag | 1 | Ester [-C(=O)-O-C] | 0.3437 | 0.3437

Frag | 1 | Aromatic bromide [-Br] | 0.1668 | 0.1668

Frag | 1 | Aromatic-CH2 | -0.0557 | -0.0557

Frag | 2 | Aromatic-CH | -0.0098 | -0.0195

Frag | 16 | Aromatic-H | 0.0082 | 0.1315

Frag | 1 | -CH2- [cyclic] | 0.0197 | 0.0197

MolWt| * | Molecular Weight Parameter | | -1.5572

Const| * | Equation Constant | | 0.7121

============+============================================+=========+=========

 RESULT | Biowin5 (MITI Linear Biodeg Probability) | | -0.0974

============+============================================+=========+=========

------+-----+--------------------------------------------+---------+---------

TYPE | NUM | Biowin6 FRAGMENT DESCRIPTION | COEFF | VALUE 

------+-----+--------------------------------------------+---------+---------

Frag | 1 | Aliphatic alcohol [-OH] | 1.0041 | 1.0041

Frag | 1 | Ester [-C(=O)-O-C] | 2.4462 | 2.4462

Frag | 1 | Aromatic bromide [-Br] | 1.5021 | 1.5021

Frag | 1 | Aromatic-CH2 | -0.1246 | -0.1246

Frag | 2 | Aromatic-CH | 0.2624 | 0.5248

Frag | 16 | Aromatic-H | 0.1201 | 1.9223

Frag | 1 | -CH2- [cyclic] | 0.2365 | 0.2365
52

MolWt| * | Molecular Weight Parameter | |-15.1108

============+============================================+=========+=========

 RESULT |Biowin6 (MITI Non-Linear Biodeg Probability)| | 0.0062

============+============================================+=========+=========

A Probability Greater Than or Equal to 0.5 indicates --> Readily Degradable

A Probability Less Than 0.5 indicates --> NOT Readily Degradable

------+-----+--------------------------------------------+---------+---------

TYPE | NUM | Biowin7 FRAGMENT DESCRIPTION | COEFF | VALUE 

------+-----+--------------------------------------------+---------+---------

Frag | 1 | Aliphatic alcohol [-OH] | 0.1328 | 0.1328

Frag | 1 | Ester [-C(=O)-O-C] | 0.1719 | 0.1719

Frag | 1 | Aromatic bromide [-Br] | 0.0000 | 0.0000

Frag | 3 | Alkyl substituent on aromatic ring | -0.1145 | -0.3434

Frag | 1 | Aromatic-CH2 | -0.0073 | -0.0073

Frag | 2 | Aromatic-CH | 0.0331 | 0.0662

Frag | 16 | Aromatic-H | -0.0954 | -1.5269

Frag | 1 | -CH2- [cyclic] | -0.1200 | -0.1200

Const| * | Equation Constant | | 0.8361

============+============================================+=========+=========

 RESULT | Biowin7 (Anaerobic Linear Biodeg Prob) | | -0.7907

============+============================================+=========+=========

A Probability Greater Than or Equal to 0.5 indicates --> Biodegrades Fast

A Probability Less Than 0.5 indicates --> Does NOT Biodegrade Fast

Ready Biodegradability Prediction: (YES or NO)

----------------------------------------------

Criteria for the YES or NO prediction: If the Biowin3 (ultimate survey

model) result is "weeks" or faster (i.e. "days", "days to weeks", or

"weeks" AND the Biowin5 (MITI linear model) probability is >= 0.5, then

the prediction is YES (readily biodegradable). If this condition is not

satisfied, the prediction is NO (not readily biodegradable). This method

is based on application of Bayesian analysis to ready biodegradation data

(see Help). Biowin5 and 6 also predict ready biodegradability, but for

degradation in the OECD301C test only; using data from the Chemicals

Evaluation and Research Institute Japan (CERIJ) database.

BioHCwin (v1.01) Program Results:

==============================

SMILES : c1cc(Br)ccc1c(cc2)ccc2C3Cc4ccccc4C(C5=C(O)c6ccccc6OC5(=O))C3

CHEM : Brodifacoum

MOL FOR: C31 H23 Br1 O3 

MOL WT : 523.43

-------------------------- BioHCwin v1.01 Results ---------------------------

 NO Estimate Possible ... Structure NOT a Hydrocarbon

 (Contains atoms other than C, H or S (-S-))

AEROWIN Program (v1.00) Results:

===============================

Sorption to aerosols (25 Dec C)[AEROWIN v1.00]:

 Vapor pressure (liquid/subcooled): 2.36E-014 Pa (1.77E-016 mm Hg)

 Log Koa (Koawin est ): 19.156

 Kp (particle/gas partition coef. (m3/ug)):

 Mackay model : 1.27E+008 

 Octanol/air (Koa) model: 3.52E+006 

 Fraction sorbed to airborne particulates (phi):

 Junge-Pankow model : 1 Mackay model : 1 

 Octanol/air (Koa) model: 1 

AOP Program (v1.92) Results:

===========================
53

SMILES : c1cc(Br)ccc1c(cc2)ccc2C3Cc4ccccc4C(C5=C(O)c6ccccc6OC5(=O))C3

CHEM : Brodifacoum

MOL FOR: C31 H23 Br1 O3 

MOL WT : 523.43

------------------- SUMMARY (AOP v1.92): HYDROXYL RADICALS (25 deg C) --------

Hydrogen Abstraction = 7.8831 E-12 cm3/molecule-sec

Reaction with N, S and -OH = 0.1400 E-12 cm3/molecule-sec

Addition to Triple Bonds = 0.0000 E-12 cm3/molecule-sec

**Addition to Olefinic Bonds = 38.5000 E-12 cm3/molecule-sec

**Addition to Aromatic Rings = 11.6952 E-12 cm3/molecule-sec

Addition to Fused Rings = 0.0000 E-12 cm3/molecule-sec

 OVERALL OH Rate Constant = 58.2183 E-12 cm3/molecule-sec

 HALF-LIFE = 0.184 Days (12-hr day; 1.5E6 OH/cm3)

 HALF-LIFE = 2.205 Hrs

........................ ** Designates Estimation(s) Using ASSUMED Value(s)

------------------- SUMMARY (AOP v1.91): OZONE REACTION (25 deg C) -----------

 OVERALL OZONE Rate Constant = 13.650000 E-17 cm3/molecule-sec

 HALF-LIFE = 0.084 Days (at 7E11 mol/cm3)

 HALF-LIFE = 2.015 Hrs

Experimental Database: NO Structure Matches

Fraction sorbed to airborne particulates (phi):

 1 (Junge-Pankow, Mackay avg)

 1 (Koa method)

 Note: the sorbed fraction may be resistant to atmospheric oxidation

KOCWIN Program (v2.00) Results:

==============================

SMILES : c1cc(Br)ccc1c(cc2)ccc2C3Cc4ccccc4C(C5=C(O)c6ccccc6OC5(=O))C3

CHEM : Brodifacoum

MOL FOR: C31 H23 Br1 O3 

MOL WT : 523.43

--------------------------- KOCWIN v2.00 Results ---------------------------

 Koc Estimate from MCI:

 ---------------------

 First Order Molecular Connectivity Index ........... : 17.081

 Non-Corrected Log Koc (0.5213 MCI + 0.60) .......... : 9.5039

 Fragment Correction(s):

 1 Aliphatic Alcohol (-C-OH) ........... : -1.3179

 1 Ester (-C-CO-O-C-) or (HCO-O-C) ...... : -1.2970

 Corrected Log Koc .................................. : 6.8890

 Estimated Koc: 7.745e+006 L/kg <===========

 Koc Estimate from Log Kow:

 -------------------------

 Log Kow (User entered ) ......................... : 8.50

 Non-Corrected Log Koc (0.55313 logKow + 0.9251) .... : 5.6267

 Fragment Correction(s):

 1 Aliphatic Alcohol (-C-OH) ........... : -0.4114

 1 Ester (-C-CO-O-C-) or (HCO-O-C) ...... : -0.0656

 Corrected Log Koc .................................. : 5.1497

 Estimated Koc: 1.411e+005 L/kg <===========

HYDROWIN Program (v2.00) Results:

================================

SMILES : c1cc(Br)ccc1c(cc2)ccc2C3Cc4ccccc4C(C5=C(O)c6ccccc6OC5(=O))C3

CHEM : Brodifacoum

MOL FOR: C31 H23 Br1 O3 

MOL WT : 523.43 --------------------------- HYDROWIN v2.00 Results --------------------------- Hydrolyzable Function detected: Cyclic Ester 
54

 -C-C(=O)-O-C...

 |____________|

 QSARs are not currently available to estimate hydrolysis rates for

 cyclic carboxlic acid esters. Rates may be similar to non-cyclic

 esters; however, steric hindrance and ring strain effects may be

 important.

 Butyrolactone (a 5-member ring) hydrolyzes very slowly in neutral

 water with the hydrolysis rate increasing in alkaline conditions (Kirk-

 Othmer, 4th ed, 1:212, 1991). In contrast, Propiolactone (a 4-member

 ring) has a reported neutral rate constant of 0.0000568/sec at 25 deg

 (Gold & Butler, 1962) which corresponds to a half-life of 3.39 days.

BCFBAF Program (v3.01) Results:

==============================

SMILES : c1cc(Br)ccc1c(cc2)ccc2C3Cc4ccccc4C(C5=C(O)c6ccccc6OC5(=O))C3

CHEM : Brodifacoum

MOL FOR: C31 H23 Br1 O3 

MOL WT : 523.43

--------------------------------- BCFBAF v3.01 --------------------------------

Summary Results:

 Log BCF (regression-based estimate): 3.39 (BCF = 2.45e+003 L/kg wet-wt)

 Biotransformation Half-Life (days) : 351 (normalized to 10 g fish)

 Log BAF (Arnot-Gobas upper trophic): 6.53 (BAF = 3.38e+006 L/kg wet-wt)

Log Kow (experimental): 8.50

Log Kow used by BCF estimates: 8.50 (user entered)

Equation Used to Make BCF estimate:

 Log BCF = -0.49 log Kow + 7.554 + Correction

 Correction(s): Value

 No Applicable Correction Factors

 Estimated Log BCF = 3.389 (BCF = 2449 L/kg wet-wt)

===========================================================

Whole Body Primary Biotransformation Rate Estimate for Fish:

===========================================================

------+-----+--------------------------------------------+---------+---------

TYPE | NUM | LOG BIOTRANSFORMATION FRAGMENT DESCRIPTION | COEFF | VALUE 

------+-----+--------------------------------------------+---------+---------

Frag | 1 | Aliphatic alcohol [-OH] | -0.0616 | -0.0616

Frag | 1 | Ester [-C(=O)-O-C] | -0.7605 | -0.7605

Frag | 1 | Aromatic bromide [-Br] | 0.3964 | 0.3964

Frag | 3 | Alkyl substituent on aromatic ring | 0.1781 | 0.5342

Frag | 1 | Aromatic-CH2 | -0.3365 | -0.3365

Frag | 2 | Aromatic-CH | -0.4629 | -0.9259

Frag | 16 | Aromatic-H | 0.2664 | 4.2620

Frag | 1 | -CH2- [cyclic] | 0.0963 | 0.0963

Frag | 2 | Number of fused acyclic rings | 0.6477 | 1.2953

Frag | 2 | Number of fused 6-carbon aromatic rings | -0.5779 | -1.1557

Frag | 1 | Biphenyl | -0.5319 | -0.5319

Frag | 1 | Tetralin | 0.0000 | 0.0000

L Kow| * | Log Kow = 8.50 (user-entered ) | 0.3073 | 2.6124

MolWt| * | Molecular Weight Parameter | | -1.3422

Const| * | Equation Constant | | -1.5058

============+============================================+=========+=========

 RESULT | LOG Bio Half-Life (days) | | 2.5451

 RESULT | Bio Half-Life (days) | | 350.9

 NOTE | Bio Half-Life Normalized to 10 g fish at 15 deg C |

============+============================================+=========+=========

Biotransformation Rate Constant:

kM (Rate Constant): 0.001976 /day (10 gram fish) 

kM (Rate Constant): 0.001111 /day (100 gram fish) 

kM (Rate Constant): 0.0006247 /day (1 kg fish) 

kM (Rate Constant): 0.0003513 /day (10 kg fish) 
55

Arnot-Gobas BCF & BAF Methods (including biotransformation rate estimates):

 Estimated Log BCF (upper trophic) = 2.986 (BCF = 967.3 L/kg wet-wt)

 Estimated Log BAF (upper trophic) = 6.529 (BAF = 3.38e+006 L/kg wet-wt)

 Estimated Log BCF (mid trophic) = 3.155 (BCF = 1430 L/kg wet-wt)

 Estimated Log BAF (mid trophic) = 6.200 (BAF = 1.586e+006 L/kg wet-wt)

 Estimated Log BCF (lower trophic) = 3.207 (BCF = 1609 L/kg wet-wt)

 Estimated Log BAF (lower trophic) = 5.952 (BAF = 8.956e+005 L/kg wet-wt)

Arnot-Gobas BCF & BAF Methods (assuming a biotransformation rate of zero):

 Estimated Log BCF (upper trophic) = 3.240 (BCF = 1739 L/kg wet-wt)

 Estimated Log BAF (upper trophic) = 6.895 (BAF = 7.844e+006 L/kg wet-wt)

 Volatilization From Water 

========================= 

Chemical Name: Brodifacoum

Molecular Weight : 523.43 g/mole 

Water Solubility : 0.0038 ppm 

Vapor Pressure : -----

Henry's Law Constant: 5.4E-013 atm-m3/mole (estimated by Bond SAR Method) 

 RIVER LAKE 

 --------- ---------

Water Depth (meters): 1 1 

Wind Velocity (m/sec): 5 0.5 

Current Velocity (m/sec): 1 0.05 

 HALF-LIFE (hours) : 2.481E+009 2.706E+010 

 HALF-LIFE (days ) : 1.034E+008 1.128E+009 

 HALF-LIFE (years) : 2.83E+005 3.087E+006 

STP Fugacity Model: Predicted Fate in a Wastewater Treatment Facility

======================================================================

 (using Biowin/EPA draft method)

PROPERTIES OF: Brodifacoum

-------------

Molecular weight (g/mol) 523.43 

Aqueous solubility (mg/l) 0.0038 

Vapour pressure (Pa) 0 

 (atm) 0 

(mm Hg) 0 

Henry 's law constant (Atm-m3/mol) 5.4E-013 

Air-water partition coefficient 2.20844E-011 

Octanol-water partition coefficient (Kow) 3.16228E+008 

Log Kow 8.5 

Biomass to water partition coefficient 6.32456E+007 

Temperature [deg C] 25 

Biodeg rate constants (h^-1),half life in biomass (h) and in 2000 mg/L MLSS (h):

 -Primary tank 0.00 999.99 1000.00

 -Aeration tank 0.01 100.00 100.00

 -Settling tank 0.01 100.00 100.00

STP Overall Chemical Mass Balance:

---------------------------------

 g/h mol/h percent

Influent 1.00E+001 1.9E-002 100.00

Primary sludge 5.90E+000 1.1E-002 58.96

Waste sludge 1.31E+000 2.5E-003 13.14

Primary volatilization 2.29E-014 4.4E-017 0.00

Settling volatilization 2.02E-014 3.9E-017 0.00

Aeration off gas 5.00E-014 9.5E-017 0.00

Primary biodegradation 1.73E-001 3.3E-004 1.73
56

Settling biodegradation 1.68E-001 3.2E-004 1.68

Aeration biodegradation 2.21E+000 4.2E-003 22.14

Final water effluent 2.35E-001 4.5E-004 2.35

Total removal 9.76E+000 1.9E-002 97.65

Total biodegradation 2.55E+000 4.9E-003 25.55

(** Total removal recommended maximum is 95 percent)

Level III Fugacity Model (Full-Output):

=======================================

 Chem Name : Brodifacoum

 Molecular Wt: 523.43

 Henry's LC : 5.4e-013 atm-m3/mole (Henrywin program)

 Vapor Press : 1.11e-018 mm Hg (Mpbpwin program)

 Liquid VP : 1.18e-016 mm Hg (super-cooled)

 Melting Pt : 230 deg C (user-entered)

 Log Kow : 8.5 (user-entered)

 Soil Koc : 7.75e+006 (KOCWIN MCI method)

 Mass Amount Half-Life Emissions

 (percent) (hr) (kg/hr)

 Air 0.0156 1.38 1000 

 Water 2.76 1.44e+003 1000 

 Soil 36.9 2.88e+003 1000 

 Sediment 60.3 1.3e+004 0 

 Fugacity Reaction Advection Reaction Advection

 (atm) (kg/hr) (kg/hr) (percent) (percent)

 Air 1.13e-022 926 18.5 30.9 0.616 

 Water 5.91e-020 157 326 5.23 10.9 

 Soil 1.34e-021 1.05e+003 0 35 0 

 Sediment 9.88e-020 381 142 12.7 4.75 

 Persistence Time: 3.94e+003 hr

 Reaction Time: 4.7e+003 hr

 Advection Time: 2.43e+004 hr

 Percent Reacted: 83.8

 Percent Advected: 16.2

 Half-Lives (hr), (based upon Biowin (Ultimate) and Aopwin):

 Air: 1.383

 Water: 1440

 Soil: 2880

 Sediment: 1.296e+004

 Biowin estimate: 1.982 (months )

 Advection Times (hr):

 Air: 100

 Water: 1000

 Sediment: 5e+004
57

Appendix C. SIPS Model Input/Output

Table 1. Inputs

Parameter Value

Chemical name Brodifacoum

Solubility (in water at 25oC; mg/L) 0.24

Mammalian LD50 (mg/kg-bw) 0.42

Mammalian test species laboratory rat

Body weight (g) of "other" mammalian 

species

Mammalian NOAEL (mg/kg-bw) 0

Mammalian test species

Body weight (g) of "other" mammalian 

species

Avian LD50 (mg/kg-bw) 0.26

Avian test species mallard duck

Body weight (g) of "other" avian species

Mineau scaling factor

Mallard NOAEC (mg/kg-diet) 0

Bobwhite quail NOAEC (mg/kg-diet) 0

NOAEC (mg/kg-diet) for other bird species

Body weight (g) of other avian species

NOAEC (mg/kg-diet) for 2nd other bird 

species

Body weight (g) of 2nd other avian species

Table 2. Mammalian Results

Parameter Acute Chronic

Upper bound exposure (mg/kg-bw) 0.0413 0.0413

Adjusted toxicity value (mg/kg-bw) 0.3230 0.0000

Ratio of exposure to toxicity 0.1278 0.0000

Conclusion*

Exposure through 

drinking water alone is a 

potential concern for 

mammals

Due to 

insufficient data, 

risk cannot be 

precluded

Table 3. Avian Results
58

Parameter Acute Chronic

Upper bound exposure (mg/kg-bw) 0.1944 0.1944

Adjusted toxicity value (mg/kg-bw) 20.5400 0.0000

Ratio of exposure to acute toxicity 0.0095 0.0000

Conclusion*

Drinking water exposure 

alone is NOT a potential 

concern for birds

Due to 

insufficient data, 

risk cannot be 

precluded

*Conclusion is for drinking water exposure alone. This does not combine all routes of exposure. 

Therefore, when aggregated with other routes (i.e., diet, inhalation, dermal), pesticide exposure 

through drinking water may contribute to a total exposure that has potential for effects to nontarget animals.
59

Appendix D. Pending and Active Registrations For

112701 / 56073-10-0 / Brodifacoum

Registration # Registration Name Company 

Name Current Status % of Active Ingredient

100-986 Brodifacoum

Concentrate

Syngenta Crop

Protection, LLC

Active - Registered (24-

Oct-1980), Concurrent -

Under Reregistration (11-

Aug-1998)

.25

100-987 Brodifacoum 

Technical

Syngenta Crop

Protection, LLC

Active - Conditionally 

Registered (24-Oct1980), Concurrent -

Under Reregistration (19-

Mar-2002), Concurrent -

Under Reregistration (11-

Aug-1998)

90

100-1050

TALON-G 

Rodenticide Bait

Pack Mini-Pellets 

With Bitrex

Syngenta Crop

Protection, LLC

Active - Conditionally 

Registered (18-Sep1991), Concurrent -

Under Reregistration (11-

Aug-1998)

.005

100-1051

TALON-G 

Rodenticide Bait

Pack Pellets With

Bitrex

Syngenta Crop 

Protection, LLC

Active - Conditionally 

Registered (18-Sep1991), Concurrent -

Under Reregistration (11-

Aug-1998)

.005

100-1052

TALON-G 

Rodenticide Pellets 

With Bitrex

Syngenta Crop 

Protection, LLC

Active - Conditionally 

Registered (23-Feb2001), Concurrent -

Under Reregistration (11-

Aug-1998)

.005

100-1053

HAVOC Rodenticide

BAIT PACK Pellets 

With Bitrex

Syngenta Crop 

Protection, LLC

Active - Conditionally 

Registered (18-Sep1991), Concurrent -

Under Reregistration (11-

Aug-1998)

.005

100-1054

HAVOC Rodenticide

BAIT PACK MINIPellets With Bitrex

Syngenta Crop 

Protection, LLC

Active - Conditionally 

Registered (18-Sep1991), Concurrent -

Under Reregistration (11-

Aug-1998)

.005

100-1055 TALON 

WEATHERBLOK XT

Syngenta Crop 

Protection, LLC

Active - Conditionally 

Registered (23-Feb2001), Concurrent -

Under Reregistration (11-

Aug-1998)

.005

100-1056

HAVOC Rodenticide

BAIT PACK Pellets 

With Bitrex

Syngenta Crop 

Protection, LLC

Active - Conditionally 

Registered (23-Feb2001), Concurrent -

.005
60

Under Reregistration (11-

Aug-1998)

100-1057

TALON-G 

Rodenticide MINIPellets With Bitrex

Syngenta Crop 

Protection, LLC

Active - Conditionally 

Registered (23-Feb2001), Concurrent -

Under Reregistration (11-

Aug-1998)

.005

100-1080 Brodifacoum 

CONCENTRATE II

Syngenta Crop 

Protection, LLC

Active - Conditionally 

Registered (17-Jul-1994), 

Concurrent - Under 

Reregistration (11-Aug1998)

.25

100-1368 WEATHER BLOK 

AG BAIT With Bitrex

Syngenta Crop

Protection, LLC

Active - Registered (15-

Apr-2010) .005

3282-RNU

D-CON BAIT 

STATION XV KILLS 

MICE

Reckitt 

Benckiser LLC

Pending - Under Review 

(18-Oct-2010) .005

3282-RNL

D-CON BAIT 

STATION XVI KILLS 

MICE

Reckitt 

Benckiser LLC Pending - Under Review 

(18-Oct-2010) .005

3282-112 d-CON® Farm, 

Ranch & Home

Reckitt 

Benckiser LLC

Active - Registered (29-

May-2014) .005

12455-88 Brodifacoum 

Technical

Bell 

Laboratories, 

Inc.

Active - Conditionally 

Registered (10-Oct1997), Concurrent -

Under Reregistration (11-

Aug-1998), Concurrent -

Under Reregistration (19-

Mar-2002)

98

12455-89 FINAL ALLWEATHER BLOX

Bell 

Laboratories, 

Inc.

Active - Conditionally 

Registered (16-Oct1997), Concurrent -

Under Reregistration (11-

Aug-1998), Concurrent -

Under Reregistration (19-

Mar-2002)

.005

12455-90 FINAL Rodenticide

Bell 

Laboratories, 

Inc.

Active - Conditionally 

Registered (21-Oct1997), Concurrent -

Under Reregistration (11-

Aug-1998), Concurrent -

Under Reregistration (19-

Mar-2002)

.005

12455-91

FINAL Rodenticide

READY-TO-USE 

PLACE PACS

Bell 

Laboratories, 

Inc.

Active - Conditionally 

Registered (16-Oct1997), Concurrent -

Under Reregistration (11-

Aug-1998), Concurrent -

.005
61

Under Reregistration (19-

Mar-2002)

12455-94 FINAL Rodenticide

PLACE PACS

Bell 

Laboratories, 

Inc.

Active - Conditionally 

Registered (14-May1998), Concurrent -

Under Reregistration (11-

Aug-1998), Concurrent -

Under Reregistration (19-

Mar-2002)

.005

12455-OI

FINAL PREBAITED 

MOUSE BAIT 

STATION

Bell 

Laboratories, 

Inc.

Pending - Under Review 

(07-May-1999) .005

12455-108 FORMUS ALLWEATHER BLOX

Bell 

Laboratories, 

Inc.

Active - Conditionally 

Registered (20-May2009)

.0025

12455-139 Final Soft Bait

Bell 

Laboratories, 

Inc.

Active - Registered (26-

Jul-2012) .0025

56228-36 Brodifacoum 25W 

Conservation

U.S. 

Department of

Agriculture

Active - Conditionally 

Registered (18-Mar2008)

.0025

56228-37 Brodifacoum 25D 

Conservation

U.S. 

Department of

Agriculture

Active - Conditionally 

Registered (18-Mar2008)

.0025

61282-27 BDF Chunks Hacco, Inc.

Active - Conditionally 

Registered (15-Jul-1997), 

Concurrent - Under 

Reregistration (11-Aug1998)

.005

61282-28 BDF Bait Packs Hacco, Inc.

Active - Conditionally 

Registered (15-Jul-1997), 

Concurrent - Under 

Reregistration (11-Aug1998)

.005

61282-EO

DESTRUCTO(TM) 

CHUNKS Kills

Rats & Mice

Hacco, Inc. Pending - Under Review 

(29-Jan-2002) .005

AZ130001 Final Soft Bait

Bell 

Laboratories, 

Inc.

Active - Registered (28-

Aug-2013) .0025

338-EUP-1 U.S. Fish and 

Wildlife Service

Active - Issued (07-Jul2006) .0025

10182-EUP-21 Syngenta Crop 

Protection, LLC

Active - Issued (27-Jul1982) 100