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# REGISTRATION REVIEW

ECOLOGICAL RISK ASSESSMENT AND

EFFECTS DETERMINATION

Coumaphos

CAS Number 56-72-4

US EPA PC CODE 036501

P

repared b y :

Robin Sternberg, Ph.D., Wildlife Biologist Faruque Khan, Ph.D., Senior Fate Scientist
Environmental Risk Branch I

R eviewed b y : Meghan Radtke, Ph.D., Biologist Stephen Wente, Ph.D., Biologist
Environmental Risk Branch I
Environmental Fate and Effects Division U. S. Environmental Protection Agency Office of Pesticide Programs
Environmental Fate and Effects Division
Environmental Risk Branch I 1200 Pennsylvania Ave., NW
Mail Code 7507P Washington, DC 20460

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## Contents

1 Executive Summary ............................................................................................................. ... 5

2 Problem Formulation ........................................................................................................... ... 9

2.1 Summary of Activity Since 2008 Problem Formulation .................................................. 9

2.2 Previous Ecological Risk Assessments .......................................................................... 11

2.3 Mode of Action .............................................................................................................. 1 2

2.4 Use Characteristics ......................................................................................................... 1 2

2.5 Conceptual Model .......................................................................................................... 15

2.5.1 Risk Hypotheses...................................................................................................... 15

2.5.2 Exposure Pathways of Concern .............................................................................. 15

2.5.3 Stressors of Concern ............................................................................................... 16

3 Fate and Transport Characterization ..................................................................................... 16

4 Exposure Assessment............................................................................................................ 18

4.1 Calculation of Application Rates ................................................................................... 18

4.1.1 Example Calculation: Manure from CA FOs (Concentrated Animal Feeding Operation) .................................................................................................................... ......... 20

4.1.2 Example Calculation: Non-Regulated Small CAFO ≤ 300 cattle .......................... 21

4.1.3 Example Calculation: Cattle Grazing in Rangeland ............................................... 22

4.2 Aquatic Exposure ........................................................................................................... 22

4.2.1 Monitoring Data ...................................................................................................... 24

4.2.2 Aquatic Exposure Modeling: Runoff ...................................................................... 24

4.2.3 Wash-off from the Skin of Treated Live stock That Enter Bodies of Water ........... 29

4.3 Terrestrial Exposure ....................................................................................................... 30

4.3.1 Birds and Mammals ................................................................................................ 30

4.3.2 Terrestrial (Upland and Se mi-Aquatic) Plants ........................................................ 36

4.3.3 Honey Bees (In-Hive Use) ...................................................................................... 37

5 Effects Characterization ...................................................................................................... .. 40

5.1 Effects to Aquatic Organisms ........................................................................................ 40

5.1.1 Freshwater Fish ....................................................................................................... 40

5.1.2 Estuarine/Marine Fish ............................................................................................. 41

5.1.3 Freshwater Invertebrates ......................................................................................... 46

5.1.4 Estuarine/Marine Invertebrates ............................................................................... 46

5.1.5 Benthic (Sediment-Dwelling) Invertebrates ........................................................... 46

5.1.6 Aquatic Plants ......................................................................................................... 47

### 4 5.2 Effects to Terrestrial Organisms .................................................................................... 47

5.2.1 Birds ........................................................................................................................ 51

5.2.2 Mammals................................................................................................................. 52

5.2.3 Non-Target Terrestrial Invertebrates ...................................................................... 52

5.2.4 Terrestrial (Upland and Se mi-Aquatic) Plants ........................................................ 55

5.3 Incident Database Review .............................................................................................. 56

6 Risk Characterization ......................................................................................................... ... 58

6.1 Risk Estimation .............................................................................................................. 58

6.1.1 Direct Effects to Aquatic Organisms ...................................................................... 58

6.1.2 Direct Effects to Terre strial Organisms .................................................................. 64

6.1.3 Probit Slope Dose-Response Analysis of LOC and Acute RQ Values .................. 70

6.2 Risk Description ............................................................................................................. 73

6.2.1 Direct Effects to Aquatic Organisms ...................................................................... 73

6.2.2 Direct Effects to Terre strial Organisms .................................................................. 76

6.3 Summary of Direct Effects ............................................................................................. 81

6.4 Listed Species Effects Determinations ........................................................................... 86

7 Uncertainties ................................................................................................................. ........ 87

7.1 Estimates of Exposure .................................................................................................... 87

7.2 Endocrine Disruptor Screen ing Program (EDSP) .......................................................... 87

8 References .................................................................................................................... ......... 88

9 Bibliography of Cited MRIDs .............................................................................................. 91

Appendix A: Example PRZM/EXAMS Output ........................................................................... 95

Appendix B: KABAM Analyses .................................................................................................. 9 9

Appendix C: ECOTOX Literature Search – Papers That Were Accepted ................................. 100

Appendix D: ECOTOX Literature Search – Papers That Were Not Acceptable ....................... 107

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## 1 Executive Summary

The purpose of this screening-leve l ecological risk assessment is to evaluate potential risks to non-target species, both non-liste d and federally-listed endange red and threatened species (hereafter referred to as non-liste d and listed species, respective ly) from registered uses of coumaphos as part of the Registration Review program 1 

### pursuant to Section 3(g) of the Federal Insecticide, Fungicide, and R odenticide Act (FIFRA).

Coumaphos (3-chloro-7-diethoxyphosphinothioyloxy- 4-methylcoumarin) is an organophosphate
insecticide/acaricide used to c ontrol flies (face fly, hor n fly), ticks, lice, mites (scabies mite) and screw worms on livestock ( e.g. , dairy cattle, horses, sheep, and swine) and swine bedding, and to
control varroa mites and small hive beetles in bee hives.

This assessment considers potential exposure to coumaphos as a result of the application of coumaphos to livestock and in-h ive use of coumaphos. The latte r exposure pathway of concern is considered only for honey bees. Table 1-1 provides a list of the exposure pathways by taxon
that are considered in this assessment for the application of coumaphos to livestock.

Table 2-1. Exposure Pathways by Taxon for Application of Coumaphos to Livestock

Taxon Exposure Pathways Assessed

Birds  contact with/ingestion of hair and skin debris from treated cattle and/or
contaminated soil and feed in and around treatment areas

 ingestion of contaminat ed bird carcasses

 ingestion of food items on land receivi ng manure from Concentrated Animal Feeding Operations (CAFOs)

 ingestion of contaminated fish

Mammals  ingestion of contaminat ed bird carcasses

 ingestion of food items on land receiving manure from CAFOs

 ingestion of contaminated fish Terrestrial plants*  uptake from CAFO manure applied to land

 uptake from soil receiving runoff from land to which manure from CAFOs has been applied Fish, aquatic invertebrates, and aquatic plants  uptake from surface waters receiving runoff from la nd to which contaminated manure has been applied

 uptake from surface waters receiving ru noff from non-regulated small CAFOs ( i.e. , < 300 animals)

 uptake from surface waters receiving ru noff from rangeland where treated livestock graze

 uptake from surface waters into which treated livestock wade ( i.e. , wash-off from treated livestock that enter bodies of water) * Given the low application rates cal culated for runoff from rangeland where treated lives tock graze (see Table 4-6 ), uptake from soil receiving runoff from rangeland where treated livestock graze was not considered to be an exposure pathway of consequence.



### A summary of direct effects to li sted and non-listed taxa from re gistered uses of coumaphos is provided in Tables 1-2 and 1-3

.

1 http://www.epa.gov/oppsrrd1/registration_review/6Table 1-2. Summary of Direct Effects for Aquatic OrganismsTaxonStatusConcernfor riskfromdirecteffects?*Basis for ConclusionRQ exceedance (type: acute and/or chronic)?Incidents?CommentsExposure pathways:Runoff from landto which CAFOmanure has beenappliedRunoff from nonregulated smallCAFOs (i.e., < 300animals)Runoff fromrangelandWash-off fromtreated livestockthat enter bodiesof waterFreshwater fishand aquatic-phaseamphibiansListedNoNoNoNoNoNo--Non-ListedNoNoNoNoNoEstuarine/marinefishListedNoNoNoNoNoNo--Non-ListedNoNoNoNoNoFreshwaterinvertebratesListedYesTexas,Rest of U.S.:Yes(acute & chronic)Texas,Rest of U.S.:Yes(acute & chronic)Texas: Yes(acute)Texas,Rest of U.S.:Yes(acute & chronic)No--Rest of U.S.: NoNonListedYesTexas,Rest of U.S.:Yes(acute & chronic)Texas,Rest of U.S.:Yes(acute & chronic)NoTexas,Rest of U.S.:Yes(acute & chronic)Estuarine/marineinvertebratesListedYesNoTexas,Rest of U.S.:Yes(acute)NoTexas,Rest of U.S.:Yes(acute & chronic)NoExposure via wash-off maynot be a complete exposurepathway given that thelikelihood of livestockentering estuarine/marinebodies of water is uncertainNonListedYesNoNoNoTexas,Rest of U.S.:Yes(chronic)Benthic(sedimentdwelling)invertebratesListedYesRQs not calculatedTexas,Rest of U.S.:Yes(acute & chronic)RQs not calculatedTexas,Rest of U.S.:Yes(acute & chronic)NoRQs were calculated usingpore water EECs and toxicityendpoints from water columnexposure studies withfreshwater invertebrates.Non-ListedYesTexas,Rest of U.S.:Yes(acute & chronic)Texas,Rest of U.S.:Yes(acute & chronic)Aquatic vascularplantsListedNoNoNoNoNoNo--Non-ListedNoNoNoNoNo7TaxonStatusConcernfor riskfromdirecteffects?*Basis for ConclusionRQ exceedance (type: acute and/or chronic)?Incidents?CommentsExposure pathways:Runoff from landto which CAFOmanure has beenappliedRunoff from nonregulated smallCAFOs (i.e., < 300animals)Runoff fromrangelandWash-off fromtreated livestockthat enter bodiesof waterAquaticnon-vascularplantsListedNARQs not calculatedNoThere is uncertaintyassociated with the riskconclusion as it is based on aqualitative analysis usingtoxicity data for a surrogateorganophosphate insecticide.NonListedNoNA = not applicable; no listed aquatic non-vascular plants* Direct or indirect effects to specific listed species have notbeen definitively determined; further investigation into temporal, geographical, and biological associations betweenthe registered uses and affected taxa is needed before definitive effects determinations can be made.Table 1-3. Summary of Direct Effects for Terrestrial OrganismsTaxonStatusConcernfor riskfromdirecteffects?*Basis for ConclusionRQ exceedance (type: acute and/or chronic)?Incidents?CommentsExposure pathways:Hair and skindebris fromtreated cattleand/orcontaminated soiland feed in andaround treatmentareasContaminatedbird carcassesCAFOmanureapplied tolandRunoff fromland to whichCAFO manurehas been appliedContaminatedfishBirds, reptiles,andterrestrial-phaseamphibiansListedYesTexas,Rest of U.S.:Yes(acute)Texas,Rest of U.S.:Yes(acute)Texas,Rest ofU.S.:Yes(acute)NATexas,Rest of U.S.:Yes(acute; selectspecies)YesRQs were not calculated for chronicexposure due to the lack of avianchronic toxicity data. However, acomparison of EECs with an avianchronic toxicity endpoint for asurrogate organophosphateinsecticide indicates that there maybe a concern for risk from directeffects for exposure via:hair and skin debris from treatedcattle and/or contaminated soiland feed in and around treatmentareas; andcontaminated fish.NonListedYesTexas,Rest of U.S.:Yes(acute)Texas,Rest of U.S.:Yes(acute)Texas,Rest ofU.S.:Yes(acute)No8TaxonStatusConcernfor riskfromdirecteffects?*Basis for ConclusionRQ exceedance (type: acute and/or chronic)?Incidents?CommentsExposure pathways:Hair and skindebris fromtreated cattleand/orcontaminated soiland feed in andaround treatmentareasContaminatedbird carcassesCAFOmanureapplied tolandRunoff fromland to whichCAFO manurehas been appliedContaminatedfishThere is uncertainty associated withthese risk conclusions for chronicexposure given the use of a toxicityendpoint for a surrogateorganophosphate insecticide.MammalsListedYesNATexas,Rest of U.S.:Yes(chronic)Texas,Rest ofU.S.:Yes(acute)NANoNo --NonListedYesTexas,Rest of U.S.:Yes(chronic)NoNoTerrestrial(upland andsemi-aquatic)plantsListedNoRQs not calculated NoThere is uncertainty associated withthe risk conclusions as they are basedon a qualitative analysis usingtoxicity data for surrogateorganophosphate insecticide.NonListedNoHoney bees(in-hive use)ListedNA**NAYesThe risk conclusion is based on aqualitative analysis.Non-ListedYesNA = not applicable* * Direct or indirect effects to specific listed species havenot been definitively determined; further investigation into temporal, geographical, and biological associations betweenthe registered uses and affected taxa is needed before definitive effects determinations can be made.** Not applicable because the analysis for in-hive use only applies to honey bees which are non-listed.

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## 2 Problem Formulation

The “EFED Ecological Risk Assessment Probl em Formulation for Coumaphos Registration Review,” which discussed the stressor and th e tools and methods with which the Agency proposed to assess potential ri sk, was completed in 2008 (DP 347376; April 28, 2008). In order to avoid repetition of material previously pr ovided, that document should be referred to for
detailed information.

2.1 Summary of Activity Since 2008 Problem Formulation

Since the 2008 problem formulation, no new scre ening-level ecological risk assessments for coumaphos were completed. However, the following studies have been submitted and reviewed: a Tier II aquatic vascular plant study with Lemna gibba (MRID 48322801); a Tier II aquatic nonvascular plant study with the green alga Pseudokirchneriella subcapitata (MRID 48322802); and an adsorption/desorption study for coumaphos and its degradate coumaphos oxon in four soil types (MRID 45721401). In addition, an aerobic soil metabolism study with coumaphos oxon in two Texas soils was submitted to the Agency (MRID 48705501). The study with L. gibba yielded a EC 50 

### of >166 μg a.i./L and a NOAEC of 166 μg a.i./L and was classified as “supplemental” due a guideline deviation ( i.e. , a the number of plants per replicate was lower than recommended). The study with P. subcapitata was classified as “invalid” because the solvent had a stimulatory effect that could have masked the true effects of coumaphos. An additional aquatic non-vascula r plant study for coumaphos wa s not requested based on an analysis presented in an EFED memo (DP 406398, October 31, 2012; see Section 5.1.6 for additional details). The adsorption/desorp tion study (MRID 45721401) for coumaphos and its degradate coumaphos oxon was classified as “partia lly acceptable” due to the unresolved issue of using a biocide as a soil sterilization proce dure. The aerobic soil metabolism study (MRID 48705501) was classified as “supplemental” due to a soil extraction procedure that may not be adequate to remove all identifiable residues from soil.

The 2008 problem formulation indicated that the Registration Review ecol ogical risk assessment would estimate risk as a result of exposure fr om the application of coumaphos to cattle and exposure from the application of bioremediated sp ent dip vat solutions to land. Risk from the former exposure pathway would be estimated using registrant-submitted data for estimating
wash-off from cow hides.

A 2007 Label Data Report 2 

### by the Biological and Economic Anal ysis Division (BEAD) indicates that a single label (Co-Ral® Fl owable Insecticide; Reg. No. 011556- 98) allows for application of coumaphos to livestock via dip vat. This label sp ecifies that use is restricted to “employees of the U.S. Department of Agriculture Animal a nd Plant Health Inspecti on Service (USDA-APHIS)
who are enrolled in the USDA-APHIS cholineste rase monitoring program.” Furthermore, the
label states that: “The Agency requires that spent dip-vat so lution be bioremediated, and recommends the bioremediation method developed by the USDA. The treated solution must be transferred

2 Date: September, 2007

### 10 to shallow, concrete-lined evaporation ponds for further degradation. The evaporation ponds must be constructed to prevent overf low or flooding during wet seasons and must
be lined with reinforced concrete. Dried sl udge generated in the evaporation ponds must not be applied to agricultural land and s hould be disposed according to solid waste disposal regulations established by your Local and/or State Environmental Control Agency. Questions concerning the disposal of spent solution should be directed to the waste representative at the nearest EPA Regional Office.”

In the 2008 problem formulation, the Agency request ed that stakeholders provide information to refine the ecological risk assessment. AP HIS responded to the request for “any current information pertaining to dispos al of bioremediated solution ( i.e. , dried sludge generated in the evaporation ponds” as follows: “There are three evaporation ponds used by CFTEP 3 

### officials in Texas. One evaporation pond is located in each of the three follo wing cities: Mission, Eagle Pass, and Laredo.
Due to the small amount of sediment in th e Mission and Eagle Pass evaporation ponds, it has not been necessary to dispose of any sedi ment from those locations. A sample of the dried sediment from the evaporation pond in Mi ssion was sent to the National Veterinary Services Laboratory (NVSL,) in Ames, Iowa for testing. The test indicated that no coumaphos was present. A small amount of dried sediment (approximately 12 feed sacks) was cleaned out of the Laredo pit, placed into a sack, and disposed of at an approved landfill. In order to support APHIS' belief that the disposal of Co-Ral used in
the CFTEP does not contribute to water cont amination, APHIS would like to take this opportunity to point to USDA's PDP monitoring data for fini shed (treated) or untreated
water. In 2005 and 2006

, no coumaphos was detected in finished water or untreated water.” (DP 347373)

Given that dried sludge generated in evapor ation ponds containing bioremediated dip vat solution is discarded in a landfill by USDA-A PHIS, EFED conclude s that exposure via application of bioremediated spen t dip vat solutions to land is not a complete exposure pathway. Therefore, risk as a result of exposure from the application of bioremediated spent dip vat
solutions to land is not estimated or ch aracterized in the present assessment.

According to the 2008 problem formulation, the indoor use of coumaphos ( e.g. , to treat swine bedding) and the placement of coum aphos-treated strips in bee hive s would not be considered in the Registration Review ecological risk assessment because they do not provide complete routes of exposure to surface waters or to the surroundin g non-target terrestrial environment. However, in a November 1, 2012 memo (DP 393874; N ovember 1, 2012), EFED reviewed the 2008 problem formulation to determine whether additiona l pollinator studies were needed to assess the potential for risk due to the re gistered use of coumaphos as an in-hive insectic ide to control
varroa mites and the small hive beetle.

The EFED memo stated: “There ar e two scenarios when the safety of a pesticide applied to an animal is a factor. In the first scenario, when a pesticide is applied to livestock, such as cattle, swine, or poultry, no safety data are required to determine if the pesticide may pose a threat to the health of the livestock. The assumption made in the absence of data is that a registrant would

3 Cattle Fever Tick Eradication Program

### 11 not have a market for a product that is not safe fo r the livestock it is mean t to protect. However, residue data are required fo r meat products of the livestock to ensure that tolerances established for the protection of human health are not exceede d. In the second scenario, when a pesticide is used as a spot-on product for para site control on a companion animal , such as a dog or cat, safety data are required to determine if the pesticide may pose a threat to the health of the companion animal (OCSPP 870.7200).”

The EFED memo then presented a 3-step analysis to assess the potential for risk to bees from the in-hive use of coumaphos. As a result of this three-step anal ysis, the memo concluded that EFED is able to qualitatively assess hazard (toxicity only) to honey bee colonies. Specifically, there is a potential for hazard to individuals of honey bee colonies, as well as hive stability, as a result of coumaphos use. The memo indicated that EFED may also be able to quantitatively characterize risk (integration of toxicity and exposure) in th e future Registration Review ecological risk assessment using the information de scribed in the memo. Therefore, based on the use pattern and exposure scenario of couma phos, EFED did not recommend requesting any further data for the effects of coumaphos on honey bees at that time. Since the writing of the memo, EFED has examined the available data and concluded that risk to bees from in-hive use of coumaphos in impregnated strips can only be asse ssed qualitatively due to the lack of data that is suitable for a quantitative approach.

2.2 Previous Ecological Risk Assessments

No ecological risk assessments for coumaphos have been conducted since the 2008 EFED problem formulation (DP 347376; April 28, 2008). The problem formulation presented the following ecological risk conclusions base d on previous ecologi cal risk assessments 4 

### conducted for coumaphos:

 Avian risk from acute exposure: Coumaphos is expected to pose acute risk to birds. Birds may be subject to primary exposure via ingestion of hair and skin debris from treated cattle or secondary exposure via ingestion of bird s killed by the pesticide, and contaminated with the pesticide.

 Avian risk from chronic exposure: The Agency concluded that avian reproduction studies were not required for coumaphos. Such studies may be required when birds are likely to be exposed to a pesticide repeatedly or continuously. According to the 1996 RED

4 Finalization of Interim Reregistration Eligibility Decisions (IREDs) and Interim Tolerance Reassessment and Risk

Management Decisions (TREDs) for the Organophosphate Pesticides, and Completion of the Tolerance Reassessment and Reregistration Eligibility Process for the Organophosphate Pesticides. July 3 1,2006. EPA 73

8-R-00- 10. EFED Drinking Water and Ecological Risk Review for Coumaphos (036501) IR-4 Use on Beehives. DP 315770.

May 16, 2006 Screening Level Aquatic Exposure Assessment for the Us e of Coumaphos in the Pacific Northwest and California to Treat Cattle via Spray and Vat Dips for the Endangered Species (ES) Consultation Package. DP 303298. June 6, 2004. US EPA Reregistration Eligibility Decision (RED) fo r Coumaphos. August 1996. EPA 738 R-96-014. EFED Review for Coumaphos RED. September 19, 1994. (EFED's environmental fate and ecological effects

sections for the Cournaphos 1996 RED)

### 12 document's assessment of acute risk, “if ther e were significant coumaphos exposure to birds, they would be killed befo re chronic effects could occur.”

 Mammalian risk from acute exposure: Couma phos is not expected to pose a risk to endangered or non-endangered mammals because the limited use pattern of coumaphos,

i.e. , treatment of cattle in confined areas, is not expected to result in significant exposure.

 Aquatic organism risk: Based on the Agency analysis, coumaphos usage on cattle is expected to pose an acute risk to aquatic i nvertebrates. Coumaphos is not expected to pose acute or chronic risks to listed or non-listed fish.

It should be noted that these risk conclusions we re revisited in the present assessment to ensure their accuracy in the context of current av ailable data and risk assessment methods.

2.3 Mode of Action

Coumaphos (O,O-diethyl O-3- chloro-4-methyl-2-oxo-21-H be nzopyran-7-yl phosphorothioate) is an insecticide/acaricide that belongs to th e organophosphate class of pesticides. The toxic mode of action of coumaphos is the inhibition of acetyl cholineste rase resulting in repeated nerve firing due to build up of acetylcholine, hyperexcitation, and eventually death.

2.4 Use Characteristics

Coumaphos was first registered in the United St ates in 1958 for use as an insecticide. A dust formulation, the first end-use product, was register ed the following year for the control of insects on cattle. Currently, coumaphos is registered fo r the control of flies (face fly, horn fly), ticks, lice, mites (scabies mite) and screw worms on livestock ( e.g. , dairy cattle, horses, sheep, and swine) and swine bedding and to control varroa mites and small hive beetles in bee hives. Coumaphos is formulated as a dust, emulsifiable concentrate, and flowable concentrate and is applied directly to livestock via dip vat, low and high-pressure hand wa nd, back rubber/oiler, mechanical duster, dust bag or shaker can.

This Registration Review ecological risk assessme nt used coumaphos app lication information as presented in the 2008 EFED problem formula tion (DP 347376; April 28, 2008) and associated label data report (Label Use Information Syst em report; LUIS) dated September 13, 2007 as well as additional information provided by BEAD ( e.g. , volume of solution mixed per animal to convert rate in lb a.i./gal as sp ecified on some labels to lb a.i. /animal). There have been no new uses of coumaphos registered since the 2008 EFED problem formulation.

Based on usage information presented in the 2008 EFED problem formulation, the largest livestock use of coumaphos is fo r cattle (59,000 lb a.i./y r for cattle vs. 12,000 lb a.i./yr for other livestock; DP 347376, April 28, 2008). Therefor e, this assessment was conducted using application rates for cattle. Maximum app lication rates (single and annual), minimum application intervals, and application met hods/equipment for cattle are provided in Table 2-1 . It should be noted that labels for coumaphos typically do not specify a maximum annual application rate. Therefore, maximum annual app lication rates were calc ulated for cattle using the maximum single application rate a nd annual number of applications.

### 13 The maximum single application rate ( i.e. , 0.027 lb a.i./animal for dip vat 5 

### ) and the maximum annual application rate ( i.e. , 0.063 lb a.i./animal for spray 6 

### ) for cattle are for the end-use product
Co-Ral® Flowable Insecticid e (EPA Reg. no. 11556-98). U se of this product is restricted to employees of the USDA-APHIS who are enrolled in the USDA-APHIS cholinesterase monitoring

program 

### . The USDA’s Cattle Fever Tick Eradication Program (CFTEP) uses this product solely in Texas. As a result, these maximum applicatio n rates were used to as sess risk to non-target species in Texas only. The next high est maximum single application rate ( i.e. , 0.01 lb a.i./A for dust or spray 7 

### ) and maximum annual application rate for cattle ( i.e. , 0.05 lb a.i./animal for back
rubbers 8 

### ) were used to assess risk to non-target species in the rest of the United States.

5 2 applications @ 0.027 lb a.i./animal = 0.054 lb a.i./animal/yr for dip vat

6 3 applications @ 0.021 lb a.i./animal = 0.063 lb a.i./animal/yr for spray

7 3 applications @ 0.01 lb a.i./animal = 0.03 lb a.i./animal/yr for spray or dust

8 6 applications @ 0.00829 lb a.i./animal = 0.05 lb a.i./animal/yr for back rubbers14Table 2-1. Application Information for Registered Uses of Coumaphos: Cattlea,b,cUseApplicationMethod/EquipmentForm.(% a.i.)Maximum SingleApplication RateAnnualNumber ofApplicationsMinimumApplicationInterval(Days)MaximumAnnualApplicationRated(lb a.i./animal)Comments(lb a.i./animal)(lb a.i./gal)Beef/range/feeder cattle;dairy cattleBack rubbersEC (11.6)0.00829(avg.; est.)0.07623.5 (avg.)NS or AS0.029--Back rubbersEC (6.2)0.00829(avg.; est.)0.03856 or NS10 or NS0.050Representsmaximumannual applicationrate for the U.S. with the exception ofTexasDip vatFC (42)0.027(est.)0.0255e2100.054EPA Reg No. 11556-98; use restricted toemployees of the USDA-APHISRepresentsmaximumannual applicationrate for TexasDustDust (1)0.013 (avg.)NS0.03Representsmaximumsingle applicationrate for the U.S. with the exception ofTexasDustDust (1)0.00133 (avg.)10 or 140.0039--DustDust (1)0.0006253 (avg.)10.0019--SprayFC (42)0.021(est.)0.0213 (avg.)100.063EPA Reg No. 11556-98; use restricted toemployees of the USDA-APHISRepresentsmaximumsingle applicationrate for TexasSprayEC (6.2)0.01(est.)0.013 (avg.)100.03Representsmaximumsingle applicationrate for the U.S. with the exception ofTexasSprayEC (11.6)0.00978(est.)0.009783 (avg.)AS0.029--Ear TagIM (20)0.006253 (avg.)NS0.019--AS = as needed; avg. = average; est. = estimated (by BEAD); NS= not specified; EM = emulsifiableconcentrate; FC = flowable concentrate; Form. =formulation; IM = impregnated material; Max. = Maximum; Min. = Minimum; NA = not applicable; RTU = ready to usealabel data report (Label Use Information System report; LUIS) dated September 13, 2007bapplication information for maximum single and annual rates in BOLDcestimated/average values provided by BEADdnot specified on label; calculated based on maximum single application rate and maximum annual number of applicationse0.306% suspension

### 15 2.5 Conceptual Model

2.5.1 Risk Hypotheses

As stated in the 2008 EFED problem formula tion (DP 347376; April 28, 2008), this Registration Review ecological risk assessment te sts the following risk hypothesis:

Non-target terrestrial and aquatic animals and plants are at risk of direct and i ndirect effects resulting from labeled uses or land disposal of coumaphos.

2.5.2 Exposure Pathways of Concern

This Registration Review ecological risk assess ment considers potential exposure to coumaphos
as a result of:

 the application of coumaphos to livestock and

 in-hive use of coumaphos. The latter exposure pathway of concern is cons idered only for honey bees. Potential exposure from the application of bioremediated spent dip vat solutions to land is not considered in the assessment because it is not a complete exposure pathway (see Section 2.1 for rationale).

The 2008 EFED problem formulation (DP 347376; April 28, 2008) provided a general conceptual model of the fate/transport and e ffects of coumaphos in the environment for the application of coumaphos to liv estock. Since coumaphos has not been detected in groundwater, exposure via irrigation water containing coumapho s was not considered in this assessment.

Table 2-2 provides a list of the exposure pathways that are considered in this assessment for the application of coumaphos to livestock.

Table 2-2. Exposure Pathways by Taxon for Application of Coumaphos to Livestock

Taxon Exposure Pathways Assessed

Birds  contact with/ingestion of hair and skin debris from treated cattle and/or
contaminated soil and feed in and around treatment areas

 ingestion of contaminat ed bird carcasses

 ingestion of food items on land receivi ng manure from Concentrated Animal Feeding Operations (CAFOs)

 ingestion of contaminated fish

Mammals  ingestion of contaminat ed bird carcasses

 ingestion of food items on land receiving manure from CAFOs

 ingestion of contaminated fish Terrestrial plants*  uptake from CAFO manure applied to land

 uptake from soil receiving runoff from land to which manure from CAFOs has been applied Fish, aquatic invertebrates, and aquatic plants  uptake from surface waters receiving runoff from la nd to which contaminated manure has been applied

 uptake from surface waters receiving ru noff from non-regulated small CAFOs ( i.e. , < 300 animals)

 uptake from surface waters receiving ru noff from rangeland where treated livestock graze

 uptake from surface waters into which treated livestock wade ( i.e. , wash-off from treated livestock that enter bodies of water)

### 16 * Given the low application rates cal culated for runoff from rangeland where treated lives tock graze (see Table 4-6 ), uptake from soil receiving runoff from rangeland where treated livestock graze was not considered to be an exposure pathway of consequence.



### 2.5.3 Stressors of Concern

2.5.3.1 Terrestrial Assessment

The stressor of concern for the terrestrial portion of this ecological risk assessment is coumaphos.

2.5.3.2 Aquatic Assessment

Coumaphoxon was detected in an aqueous photod egradation study at a ma ximum of 10.2% of applied chemical (MRIDs 42764101 and 43103901). Ther efore, the stressors of concern for the aquatic portion of this assessment are coum aphos and its oxygen analog coumaphoxon (O,Odiethyl O-3-chloro-4-methyl-2-oxo-2-H- 1-benzopyran-7-yl phosphate).



## 3 Fate and Transport Characterization

Coumaphos (O-[3-chloro-4-methyl -2-oxo-2H-1-benzopyran -7-yl] O,O-diethyl phosphorothioate) is an organophosphate insecticide/acaricide. Physical, chemical and environmental fate properties of coumaphos are presented in Table 3-1

. Coumaphos has a relatively low vapor pressure (1.0 × 10 -7 

### mm Hg) and Henry’s Law constant (4.62 × 10 -9 

### atm·m 3 

### /mol), which suggest that volatilization is not expect ed to be a major route of dissi pation from soil and water. A
limited environmental fate database for coum aphos indicates that it is persistent (DT 50 

### of >1 year in aerobic soil) and slightly mobile to hardly mobile (K foc 

### of 1874 to 10297 L/Kg) in soil according to FAO classification of mobility in soil (FAO, 2000). Hydrolysis is also not a significant route of dissipation fo r coumaphos. In two field dissipation studies where coumaphos was applied at 300 ppm with and without inco rporation, the half-life of coumaphos was determined to be 118 and 185 days. Although the soil was not sampled deep enough to define the extent of leaching, samples taken at the 6- to 12-inch depth (the deepest layer sampled) contained between 25-375 ppm at 32 weeks and 5-69 ppm at 52 weeks post-treatment. The terrestrial field dissipation studi es indicate that coumaphos is re latively persistent, as was also indicated by the aerobi c soil metabolism study.

The major pathway of coumaphos degradation appears to be photodegradation in water (DT 50 

### of 33 hours). A major degradate, oxygen anal og coumaphoxon, was detected in an aqueous photodegradation study at a maximum of 10.2% of applied chemical. Limited environmental fate data for coumaphoxon ( Table 3-2 ) suggest that it is not a persistent compound in the terrestrial environment (aerobic soil metabolism DT 50 

### of 0.49 to 2.27 days) and that it is mobile to moderately mobile (K foc 

### of 767 to 5810 L/Kg) in soil according to FAO classification of mobility in soil (FAO, 2000). Total coumaphos re sidues accumulated in bl uegill sunfish with a
maximum bioconcentration factor of 541X in whole fish during 30 days of exposure to coumaphos. Accumulated couma phos residues were depurated rapidly, with 95% elimination after 1 day in untreated water.

### 17 Table 3-1. Physical, Chemical and Envi ronmental Fate Properties of Coumaphos

Parameter Value Source Common name Coumaphos

USEPA, 2007 Chemical name 3-chloro-7- diethoxyphosphinothioyloxy-4- methylcoumarin

CAS # 56-72-4

CAS Name O -(3-chloro-4-methyl-2-oxo-2 H -1- benzopyran-7-yl) O,O -diethyl phosphorothioate Empirical formula C 14 H 16 ClO 5 PS

Structure

Molecular mass 362.5 USEPA, 2007 Water solubility (20  C) 20 mg/L USEPA, 2007
Vapor pressure (20  C) 1.0E-07mm Hg USEPA, 2007
Henry’s Law Constant 2.62E-09 atm m 3 /mol Estimated Octanol/water partition coefficient (Log K
ow ) 4.3 TOXNET

Hydrolysis (DT 50 ) Stable at pH 5,7 and 9 USEPA, 1993a

MRIDs

00150197

00159928

Direct Aqueous Photolysis (DT 50 ) 1.38 days MRID 42764101

MRID 43103901

Soil Photolysis 24 days 40 days MRID 42920301

MRID 43167401 Aerobic Soil Metabolism (DT 50 ) Stable a MRID 40518701 Anaerobic Soil Metabolism (DT 50 ) No Data --- Aerobic Aquatic Metabolism (DT 50 ) No Data --- Soil Partition Coefficient (K f )

Soil Partition Coefficient (K foc ) 57.3 L kg -1 for Sand 26.0 L kg -1 for Sandy Clay Loam 65.2 L kg -1 for Clay Loam 65.9 L kg -1 for Clay Loam

5257 L kg o.c. -1 for Sand 6190 L kg o.c. -1 for Sandy Clay Loam 1874 L kg o.c. -1 for Clay Loam 10297 L kg o.c. -1 for Clay Loam MRID 45721401

Mobility-Leaching Column Study (Aged sample)

Immobile MRID 00163806

Terrestrial Field Dissipation (DT 50 ) 185 days (in the upper 6 inches of soil) MRID 00115166

Bioconcentration (BCFs) 541X Whole Fish MRIDs
00115168 and

00150619

### 18 a Since the revised DT 50 of 2752 days (calculated using the NAFTA Guidance, USEPA, 2012a) is well beyond the duration of the study (365 days), the aerobic soil half-life is considered as stable.



### Table 3-2. Physical, Chemical and Enviro nmental Fate Properties of Coumaphoxon

Parameter Value Source

Chemical Structure MRID 48705501

Chemical Name Coumaphos Oxon MRID 48705501

CAS Name O-(3-Chloro-4-methyl-2-oxo-2H-1- benzopyran-7-yl)O,O-diethyl phosphate MRID 48705501

IUPAC 3-Chloro-4-methyl-2-oxo-2H-1-benzopyran7-yl diethyl phosphate MRID 48705501

Molecular Weight 346.71 EPISUITE 4.1

Solubility (25° C) 31.61 mg/L (Based on Log K OW Method) 210.46 mg/L (Fragment Method) EPISUITE 4.1

Vapor pressure (25  C) 7.68 x 10 -8 mm Hg EPISUITE 4.1 Henry’s Law Constant 1.10 x 10 -9 atm m 3 /mol EPISUITE 4.1 Octanol/water partition coefficient (Log K
ow ) 2.71 EPISUITE 4.1 Soil Partition Coefficient (K f )

Soil Partition Coefficient (K foc ) 11.4 L -1 kg for Sand 24.4 L kg -1 for Sandy Clay Loam

26.7 L -1 kg for Clay Loam

26.0 L -1 kg for Clay Loam

1046 L kg o.c. -1 for Sand 5810 L kg o.c. -1 for Sandy Clay Loam 767 L kg o.c. -1 for Clay Loam 4063 L kg o.c. -1 for Clay Loam MRID 45721401 a

198.4 L kg EPISUITE

Aerobic soil Metabolism (DT 50 ) Silt soil 0.49 days Loamy Sand soil 2.27 days MRID 48705501

a Soil partition coefficient va lues reported in MRID 45 721401 are problematic. In a recent study, there was a substantial degradation (0 – 92%) of the coumaphoxon during the 24-hr equilibration period (personal communication-via email on 6/24/2013) possibly due to hydrolysis.



## 4 Exposure Assessment

4.1 Calculation of Application Rates

During a rain event, a certain fraction of co umaphos wash-off from treated cattle can be potentially adsorbed into manure as well as transported as ru noff from CAFOs and pasture/rangeland. Estimated exposure concentr ations (EECs) from r unoff and wash-off were
calculated for Texas and the rest of the U.S. using maximum applicatio n rates for cattle (see

Section 2.4 for application rates and rationale) as well as data from acceptable registrantsubmitted studies quantifying the fraction of coumaphos that becomes available for exposure after soaking a cow hide in water ( i.e. , wash-off fraction; Table 4-1 ).

### 19 In registrant-submitted wash-off studies, fresh co w hides were treated with either Co-Ral® 11.6% emulsifiable liquid (MRID 42512601) or Co-Ral® 25% wettable powder (MRID 42512602) and then dried for 0.5, 3, or 24 hours. The wash-off fraction was measured after hides had been soaked in water for 0.5, 1, 2, or 4 hours. Results of thes e studies indicate that wash-off fraction is inversely related to drying time and de pendent upon the formulation ( Table

4-1 ) but not affected by soaking time (data not show n). Although not the most conservative, wash-off fractions for the 24-hour drying time we re used in this assessment because they represent a reasonable time frame after application for a treated cow to be caught in a rainstorm or enter a body of water.

Table 4-1. Percent Wash-Off for Different Form ulations of Coumaphos at Different Drying Times (MRIDs 42512601 and 42512602)

Formulation (%) Drying Time (hrs) Wash-Off

Fraction Comment

Emulsifiable powder/concentrate (11.6) 0.5 0.116 Represents formulation associated with maximum application rates for the U.S. with the exception of Texas (back rubbers and spray) 3 0.046

24 0.027

Wettable powder/flowable concentrate (25) 0.5 0.38 Represents formulation associated with maximum application rates for Texas (dip vat and spray) 3 0.21

24 0.02



### To accurately characterize the potential envi ronmental exposure pathways, selecting the appropriate livestock management system and various exposure pathway scenarios is necessary.
Several scenarios were considered to estimate the application ra te for coumaphos and potential exposure to coumaphos for terrestrial and aqua tic environments. The following scenarios and example calculations of application rates are base d on spray (Texas) or back rubber (rest of the U.S.) application on cattle. Table 4-2 provides application rate s for various scenarios.

Table 4-2. Estimated Coumaphos Applic ation Rates for Various Scenarios a

Sources of a.i. from Application Scenario Wash-Off

Fraction Maximum Single Application Rate (lb/A) Number of Applications/

Year Maximum

Annual Application Rate (lb/A) Texas: Spray Application (42% flowable concentrate) CAFO manure applied to land b No incorporation of manure into soil

0.02 0.015 1 c 0.015 Incorporation of manure into soil within a day

0.02 0.009 1 c 0.009 Runoff from small non-regulated CAFO 0.02 0.008 12 d 0.096 Runoff from range land 0.02 0.00013 3 0.0004 Rest of U.S.: Back Rubber Applicatio n (11.6% emulsifiable concentration) CAFO manure applied to land b No incorporation of manure into soil

0.027 0.0092 1 c 0.0092 Incorporation of manure into soil within a day

0.027 0.0051 1 c 0.0051 Runoff from small non-regulated CAFO 0.027 0.0050 12 d 0.0603 Runoff from range land 0.027 0.0001 3 0.0003

AU = animal unit

a Sample calculations provided in Sections 4.1.1 to 4.1.3

### 20 b Application rate of coumaphos depends on nutrient management and application method of manure.

c Application rate can be split based on total nitr ogen (TN) requirement dur ing the growing season.

d Three or two applications/stocking period; maximum four stocking periods based on http://www.epa.gov/agriculture /ag101/beefproducts.html



### 4.1.1 Example Calculation: Manure from CAFOs (Concentrated Animal Feeding Operation)

Manure used as a soil amendment/organic fertilizer could be a potential sour ce for pesticides that
are embedded in it from wash-off from treated liv estock. Since coumaphos is stable in soil, degradation was not considered. Application rate of coumapho s was estimated based on dry weight of manure application for crop production. The following step s were used to calculate the application rate of coumaphos.

Step 1 : Total dry weight of manure (DM)/AU(animal unit) /year

DM = 8.5 lb solid in manure [ASAE, 2003] /AU x 365 days = 3103 lb dry manure/AU/year or 1.55 tons/AU/year

Step 2 : Active ingredient in manure (AM) lb a.i./AU

AM = (A x F x S x W x PA) lb a.i./AU/year

Where: A = application rate: 0.021 lb /AU for spray application ( Table 2-1 ) F = frequency of application: 3/AU/year ( Table 2-1 ) S = # of stocking/year: 4 (Based on 90-120 days stocking period for cattle in feedlot 9 

### ) W = wash-off fraction: 0.02 (Texas; coumaphos formulations restricted to APHIS) or 0.027 (for non-restricted coumaphos formul ations; rest of the U.S.) (MRIDs 42512601 and 42512602) PA = potential fraction of coumaphos washed off of cattle during a rain event that can come into contact with and adsorb to manure: 0.36 (assumed based on EPISUITE estimate for adsorption into sludge)

Sample calculation is based on Co-Ral® Flowable Insecticide: AM = (0.021 x 3 x 4 x 0.02 x 0.36) = 0.0018 a.i. lb/AU

Step 3 : Active ingredient in manure (lb a.i./ton)

(0.0018 lb a.i./1.55 ton manure) = 0.0012 lbs a.i./ton dry manure

Step 4: Total nitrogen production (TN) per animal (lbs TN/AU/year)

TN = (N x L x V x D) lbs TN/AU/year

Where: N = nitrogen content in manure per AU (TN lb/AU) (ASABE, 2003)

9 http://www.epa.gov/agriculture /ag101/beefproducts.html

### 21 L = average fraction of N retained during storage and handling: 0.5 (Table 11.5, USDA, 2008). The range of N retention varies from 40 to 60 for arid region and 55 to 70 in humid region.
V= Fraction of N loss due to volatilization: 0.1 (based on next day incorporation into soil after application in warm wet soil conditio n) to 0.5 (based on no incorporation for seven days into soil) (Table 11.6, USDA, 2006). The range of volatility loss varies from 50 percent in warn dry soil to 10 percen t in cool wet soil. In addition, volatility loss may also depend on method of ma nure application (i.e. 5% and 25% volatilization loss from injection and sprinkl ing methods respectively. Since there is an inverse relationship between volatilizati on loss and application rate of manure, the highest and lowest volatili zation rate was considered to calculate application rate of coumaphos. D = 365 of days /year

Sample calculation: TN = (0.34 x 0.5 x 0.5 x 365) = 31 lbs TN in manure/AU/year [For no incorporation for seven days under warm dry soil scenario]

Step 5 : Total N in manure (lb/ton manure)

(31 lbs TN/1.55 ton manure) = 20 lbs TN/ton manure/AU

Step 6: Application rate of manure (ton/acre)

In general, the application rate of manure is based on TN recommendation for crop types. For example, 250 lb TN/acre per year requires for growing warm se ason perennial grass in Texas 10



### .

Sample calculation: (250 lbs TN/acre) x (1 ton Manure /20 lbs TN) 12.5 tons manure/acre require for gr owing perennial grass in Texas

Step 7: Application rate of active ingredient (lb/acre)

(0.0012 lbs a.i/ton) x (12.5 tons manure/acre) = 0.015 lbs a.i./acre

Therefore, the application rate of 0.015 lbs a. i/A is based on 2% coumaphos wash-off from
treated cattle.

4.1.2 Example Calculation: Non-Regulated Small CAFO ≤ 300 cattle

Runoff of washed-off coumaphos from treated cattl e could be a major contributor from an open non-regulated feedlot. Applica tion rate was estimated from runoff contribution based on washoff fraction of coumaphos and animal density per acre. The following equation was used in calculating application rate:

10 Stichles and McFarland, http://agrilifeextension.tamu.edu/

### 22 Application Rate (AR) of active Ingredient (lb/A) AR (lb a.i./A) = (A x F x S x C x W x PR X FF)

Where: A = application rate: 0.021 a.i. lb/AU (spray application) F = frequency of applicati on: 3 (spray application) S = # of stocking/year: 4 (Based on 90-120 days stocking period for cattle in feedlot 11 

### ) C = # of AU in feedlot: 300 (Maximum cattle density in non-regulated CAFOs). The amount of pen space per animal (stocking density) depends upon climate and whether the lots are paved (50 to 75 ft 2 

### /animal) or earthen (250 to 500 ft 2 

### /animal). Others report stocking densities to range between 150 to 300 ft 2 

### /animal. W = wash-off fraction: 0.02 (Texas) or 0.027 (rest of the U.S.) (MRIDs 42512601 and 42512602) PR = potential removal through adsorption of coumaphos into manure: 0.64 (1-0.36) (based on EPISUITE estimate for adsorption of coumaphos into sludge)
FF = fraction of feedlot for 10 hectare scenar io: 0.1 (based on 3 acres (1 ha) for 300 AU, where density of 100 cattle/acre; Murphy and Harner, 2006).

Sample calculation: AR = (0.021 x 3 x 4 x 300 x 0.02 x 0.64 x 0.1) = 0.0096 lb a.i./A/yr

4.1.3 Example Calculation: Cattle Grazing in Rangeland

Runoff of washed-off coumaphos from treated cattl e could be a major contributor from treated cattle grazing on rangeland. Application rate wa s estimated from runoff contribution based on wash-off of coumaphos and anim als stocking rate per acre.

Application Rate (AR) of ac tive Ingredient (lbs/Acre) AR = (A x F x C x W)

Where: A = application rate: 0.021 lb /AU (spray application) F = frequency of applicati on: 3 (spray application) C = # of AU in pasture/land: 0.3 was based on 800 lbs cattle (Pratt and Rasmaussan, 2001). There is an inverse relationship be tween weight of ca ttle and number of AU in pasture/land. Numbers of AU on pasture land also depends on the size of cattle and forage production. W = wash-off fraction: 0.02 (Texas) or 0.027 (rest of the U.S.) (MRIDs 42512601 and 42512602)

Sample calculation: AR = (0.021 x 3 x 0.3 x 0.02) = 0.0004 lb/A

4.2 Aquatic Exposure

Exposure of aquatic organisms to coum aphos could occur as a result of:

11 http://www.epa.gov/agriculture /ag101/beefproducts.html

### 23  uptake from surface waters receiving runoff fr om land to which contaminated manure has been applied;

 uptake from surface waters receiv ing runoff from small CAFOs ( i.e. , < 300 animals);

 uptake from surface waters receiving runo ff from rangeland where treated livestock graze; and

 uptake from surface waters into which treated livestock wade ( i.e. , wash-off from treated livestock entering bodies of water).

As stated in the problem form ulation, the stressors of c oncern for aquatic exposure are coumaphos and its oxygen analog coumaphoxon. There are no data available for the toxicity of coumaphoxon to aquatic organisms. However, a comparative acute toxic ity study by Tsuda et al. (1997) with organophosphate insecticides – di azinon, malathion, fenitrothion, and EPN) and their oxygen analogs – diazinon oxon, malaoxon, fenitrothion oxon, and EPN oxon, respectively – generally indicates that the oxidation product is more toxic than the parent to fish ( Table 4-3 ). In contrast, enzymatic conversion to the oxon domi nates hydrolysis of any of the ester linkages in insects suggesting that the oxon and parent are equally toxic to these organisms (Fest and Schmidt, 1973). Therefore, the acute toxicity of coumaphos was assumed to be equivalent to the acute toxicity of its oxidation produc t for aquatic invertebrates. Equi valent toxicity of parent and oxidation product was also assumed for aquatic plants due to the lack of toxicity data. As a result, different approaches we re taken to calculate aquatic acute EECs for fish and aquatic invertebrates and plants. For fish, a toxic e quivalency (TEQ) approach was taken using the average toxic equivalency factor calculated for the four organ ophosphate insecticides tested by Tsuda et al. (1997) ( i.e. , 7.25; see Table 4-3 ) since all the data came from the same laboratory, thereby eliminating inter-laboratory variabilit y. The equations for the TEQ approach are provided in Table 4-4

. Specifically, surface water peak EECs for coumaphos were modeled via PRZM/EXAMS and then adjusted for formation a nd toxicity of the oxidation product to yield a parent equivalent peak EEC (parent coum aphos + degradate coumaphoxon). For aquatic invertebrates and plants, the total toxic equivale nt residue (TTER) approach, which is similar to
the total toxic residu e approach, was taken using the equation in Table 4-4 which yields peak EECs (parent coumaphos + degradate coumaphoxon) that are equal to the surface water peak EECs for coumaphos modeled via PRZM/EXAMS.

Since comparative chronic toxi city studies are not availa ble for parent organophosphate
insecticides and their oxidati on products, a TTER approach was used for fish and aquatic invertebrates using the equation in Table 4-4 which yields total chronic EECs that are equal to surface water chronic EECs for coumaphos modeled via PRZM/EXAMS.

Table 4-3. Calculation of Toxic Equivalency Factors (TEQs) for Four Organophosphate

Insecticides

Parent (MW) Oxidation Product (MW) 48-hr LC 50 a TEQ

Parent 48-hr LC 50 (μmol/L):

Oxidation Product LC 50 (μmol/L) Parent Oxidation Product mg/L μmol/L mg/L μmol/L Diazinon (304.35) Diazinon oxon (288.28) 4.4 14.46 0.22 0.76 18.94

Malathion (330.4) Malaoxon (314.29) 1.8 5.45 0.28 0.89 6.12

### 24 Parent (MW) Oxidation Product (MW) 48-hr LC 50 a TEQ

Parent 48-hr LC 50 (μmol/L):

Oxidation Product LC 50 (μmol/L) Parent Oxidation Product mg/L μmol/L mg/L μmol/L Fenitrothion (227.23)
Fenitrothion oxon (261.17) 3.5 12.62 6.8 26.04 0.48

EPN (323.3) EPN oxon (307.24) 4.4 1.79 0.16 0.52 3.44

MW = molecular weight (g/mol)

a based on data from Tsuda et al., 1997 Average 7.25



### Table 4-4. Equations for Calculating Aquatic Total Estimated Environmental Concentrations (EECs) a nd Risk Quotients (RQs)

Exposure

Duration Taxon Approach EEC (parent+oxon) Acute RQ

Acute Fish Toxic equivalency = (% formed (parent) *Peak EEC (parent) *TEQ (parent) ) + (% formed (oxon) *Peak EEC (parent) *TEQ (oxon) ) = (0.9*Peak EEC (p arent ) *1) + (0.1*Peak EEC (p arent ) *7.25) Peak EEC (parent+oxon) /

Most sensitive LC 50(parent)

Aquatic
invertebrates and plants Total toxic equivalent
residues (% formed (parent) *Peak EEC (parent) ) + (% formed (oxon) *Peak EEC (parent) ) = (0.9*Peak EEC (parent) ) + (0.1*Peak EEC (parent) )
= Peak EEC (p arent ) Peak EEC (parent) / Most sensitive endpoint (parent)

Chronic Fish and aquatic
invertebrates Total toxic equivalent
residues (% formed (parent) *Chronic EEC (parent) ) + (% formed (oxon) *Chronic EEC (parent) ) = (0.9*Chronic EEC (parent) ) + (0.1*Chronic EEC (parent) )
= Chronic EEC (p arent ) Chronic EEC (parent) / Most sensitive endpoint (parent)

% formed (oxon) = % formed in the aqueous photodegradation study = 0.1
% formed (parent) = 1- (% formed (oxon) )
Peak EEC (parent) = Peak EEC for coumaphos from PRZM/EXAMS
Chronic EEC (parent) = 21-day or 60-day EEC for coumaphos from PRZM/EXAMS for aquatic invertebrates and fish, respectively TEQ (parent) = 1 TEQ (oxon) = 7.25 (from Table 4-3 )



### 4.2.1 Monitoring Data

Coumaphos is not included as one of the analyt es monitored in the U.S. surface and groundwater under the USGS’s National Water Quality Assess ment (NAWQA) program. Monitoring data for surface water, groundwater and sediment from the California Department of Pesticide Regulation (CDPR) were searched on September 9, 2013, and all data with analysis for coumaphos were extracted. No detection was reported in surf ace water and groundwater, and coumaphos was not monitored in sediment ( http://www.cdpr.ca.gov/docs/emon/ehap.htm ).

4.2.2 Aquatic Exposure Modeling: Runoff

Screening-level surface water exposures for runo ff were conducted for coumaphos use on cattle. Modeled application rates repres ent the application rate estimat es based on wash-off fractions from treated cattle ( Table 4-1 ). Table 4-2 provides various applicati on rates used for assessing exposure via runoff. Wash-off fractions for the 24-hour drying time were used in the aquatic exposure assessment because they represent a reasonable time frame after application for a treated cow to be caught in a ra instorm or enter a body of water.

### 25 The Pesticide Root Zone Model, (PRZM) and the Exposure Analysis Modeling System (EXAMS) were used in tandem to generate a quatic estimated environmental concentrations (EECs) for parent coumaphos. PRZM (3.12.2 date d May 12, 2005) simulates fate and transport on the agricultural/range land whereas EXAM S (2.98.04.06, dated April 25, 2005) simulates the fate and resulting daily concentrations in the water body. Simulations ar e carried out with the linkage program shell, PE5V01.pl (dated Novemb er 15, 2006), which incorporates the standard non-agricultural scenarios devel oped by EFED. Simulations are run for multiple (usually 30) years, and the EECs represent pe ak values that are expected once every ten years based on the thirty years of daily values generated during the simulation. Additional information on these
models can be found at: http://www.epa.gov/oppefed1/models/water /index.htm

.

Aquatic exposure is estimated for the maximum a pplication pattern to a 10-ha field bordering a 1-ha pond, 2-m deep (20,000 m 3 

### ), with no outlet. Exposure es timates generated using this standard pond are intended to represent a wide variety of vulnerable wate r bodies that occur at the top of watersheds including prairie pot holes , playa lakes, wetlands, vernal pools, man-made and natural ponds, and intermittent and first-order streams. As a group, there are factors that
make these water bodies more or less vulnerable than the standard surrogate pond. Static water bodies that have larger ratios of pesticide-treated drainage area to water body volume would be expected to have higher peak EECs than the st andard pond. These water bodies will be either smaller in size or have large drainage areas. Sm aller water bodies have limited storage capacity and thus may overflow and carry pesticide in th e discharge, whereas th e standard pond has no discharge. Headwater streams can also have p eak concentrations higher than the standard pond, but they likely persist for only short periods of time and are then carried and dissipated downstream. Estimates of coumaphos exposure via runoff from the application of treated manure and CAFOs to agricultural fiel ds are also highly uncertain.

Inputs for PRZM/EXAMS are provided in Table 4-5 . EECs for surface water (water column) are provided in Table 4-6 . Pore water concentrations were additionally modeled for the scenario that yielded the most conservative surface water EECs for each runoff exposure pathway ( i.e.

, Range BSS for rangeland; and PA turf for ma nure and non-regulated small CAFOs) and are provided in Table 4-7 . PRZM/EXAMS modeling output of EECs for an example scenario (PA Turf) is provided in Appendix A

.

Table 4-5. PRZM/EXAMS Input Parameters for Coumaphos

Parameter Input Value Source Comment

Use Site Pasture a
FLTurf
BSS Turf b

PA Turf Rangeland BSS Rangeland 2 --- Assumed coumaphos treated animals grazing on pasture or rangeland

Application Date (DD-MM) Manure: 15 -10
CAFO Run off: 15- 01
Pasture Runoff: 15-04 Fall application Assumed four stocking/year Spring for grazing Application Rate Table 4-2 See calculation ( Section

4.1 ) Number of applications per

year 1 to 12 Table 4-2 Number of application and application frequency based

### 26 Parameter Input Value Source Comment Application interval (days) 10 Table 4-2 on either manure or runoff
scenarios Application method Hand-held spray or dip vat
method Label directions ---

CAM 1 --- Surface application of

manure 1 -- Assumed for wash-off from
animal hide 4 -- Incorporation of manure to a depth of 8 inches (20.3 cm) c Hydrolysis (t 1/2 ) 0 MRID

46902201 Stable

Spray drift fraction No t applicable --- --- Aerobic soil metabolism (t 1/2 ) 0 day (stable) MRID

40518701 Aerobic aquatic metabolism (t 1/2 ) 0 day (stable) No Data Input Parameter Guidance (USEPA, 2009) Anaerobic aquatic metabolism (t 1/2 ) 0 day No Data Input Parameter Guidance (USEPA, 2009) Aquatic photolysis (t 1/2 ) 1.38 days MRID

42764101

MRID

43103901 ---

Vapor pressure 1. 0E-07 (mmHg) US EPA, 2007 --- Solubility in water (pH 7, 20 °C) 20 mg/L

Molecular weight 362.78 g/mole Henry’s Law constant (20 °C) 2.62E-09 atm.m 3 /mol Estimated d

Partition coefficient K
oc 5904 mL/g MRID

46808411 Represents average K
oc for 4
soils

a Turf scenarios were used as surrogate scenarios for pasture land

b Major use of coumaphos is in dip vats by USDA (APH IS) on the Texas-Mexico border for cattle coming into the United States from Mexico in the tick quarantine zone in Texas. Since no PRZM/EXAMS standard scenario is available for Texas, BSS Turf and BSS Rangeland were used as surrogate scenarios for coumaphos

c http://ohioline.osu.edu/agf-fact/0208.html

d http://www.epa.gov/oppefed1/models/w ater/input_parameter_guidance.htm27Table 4-6. Estimated Environmental Concentrations (EECs)of Coumaphos in Surface Water from Runoff for VariousApplication ScenariosPRZM/EXAMSScenarioSources of a.i.from Application ScenarioWash-OffFractionPeak EEC(parent)(μg/L)(Coumaphos)Peak EEC(parent+oxon)* (μg/L)(Coumaphos + Coumaphoxon)Chronic EEC(parent+oxon)* (μg/L)(Coumaphos + Coumaphoxon)FishAquatic Invertsand Plants21-day(Aquatic Inverts)60-day(Fish)Texas: Spray Application (42% flowable concentrate)BSSTurfaRunoff from CAFO manureapplied to landNo incorporation of manure into soil0.02 0.05 0.08 0.05 0.03 0.03Incorporation of manure into soil within a day0.02 0.0031 0.01 0.0031 0.0021 0.0018Runoff from non-regulatedsmall CAFO0.02 0.25 0.41 0.25 0.21 0.18RangeBSSbRunoff from rangeland 0.02 0.005 0.01 0.005 0.004 0.004Rest of U.S.: Back Rubber Application (11.6% emulsifiable concentration)FL Turf Runoff from CAFO manureapplied to landNo incorporation of manure into soil0.027 0.02 0.03 0.02 0.02 0.01Runoff from non-regulatedsmall CAFO0.027 0.14 0.23 0.14 0.10 0.09Runoff from rangelandb,c0.027 0.0006 0.0010 0.0006 0.0005 0.0004PA Turf Runoff from CAFO manureapplied to landNo incorporation of manure into soil0.027 0.04 0.07 0.04 0.03 0.03Incorporation of manure into soil within a day0.027 0.0022 0.0036 0.0022 0.0018 0.0017Runoff from non-regulatedsmall CAFO0.027 0.29 0.47 0.29 0.23 0.21Runoff from rangelandb,c0.027 0.00130.00210.00130.00110.0010AU = animal unit* Used to calculate RQsaUsed as surrogate scenario for pasture landbCattles grazing on rangelandcIn absence of rangeland scenario in FLand PA, turf scenarios from FL and PA wereused as surrogate scenarios for rangeland.28Table 4-7. Estimated Environmental Concentrations (EECs)of Coumaphos in Pore Water from Runoff for SelectedApplication ScenariosPRZM/EXAMSScenarioSources of a.i.from Application ScenarioWash-OffFractionPeak EEC(parent+oxon)(μg/L)(Coumaphos + Coumaphoxon)21-day EEC(parent+oxon)(μg/L)(Coumaphos + Coumaphoxon)Ratio ofSurface Water EEC(parent+oxon)a:Pore Water EEC(parent+oxon)Peak21-dayTexas: Spray Application (42% flowable concentrate)BSSTurf Runoff from non-regulatedsmall CAFO0.02 0.17 0.17 1.5 1.2Rest of U.S.: Back Rubber Application (11.6% emulsifiable concentration)PA Turf Runoff from non-regulatedsmall CAFO0.027 0.19 0.19 1.5 1.2aPeakEEC(parent+oxon)for aquatic invertebrates fromTable 4-6

### 29 4.2.3 Wash-off from the Skin of Treated Livestock That Enter Bodies of

Water

For aquatic exposure from wash-off from the skin of treated livestock that enter bodies of water:

 Surface water EECs were calculated as “EEC per treated cow wading into a body of water” ( i.e. , EEC/cow; Table 4-8 ) using the maximum single application rates of 0.027
and 0.01 lb a.i./animal for Texas and the rest of the U.S., respectively. The equation provided in Table 4-9 was used to generate surface water EECs for coumaphos which were then adjusted using the TEQ and TTR approaches to yield total EECs (coumaphos + coumaphoxon).

 Pore water EECs were calculated as EEC/cow ( Table 4-10 ) using surface water EECs ( Table 4-6 ) and the ratio of surface water EEC (parent+oxon) 

### : pore water EEC (parent+oxon) 

### for runoff ( Table 4-7 ).

Table 4-8. Surface Water Estimated Environmen tal Concentrations (EECs) from WashOff from the Skin of Treated Live stock That Enter Bodies of Water

Maximum Application Rate Wash-Off

Fraction c Peak

EEC (parent) /cow d (μg/L) (Coumaphos) Peak EEC (parent+oxon) /cow d (μg/L)
(Coumaphos + Coumaphoxon) Chronic

EEC (parent+oxon) /cow d (μg/L) (Coumaphos + Coumaphoxon) Type (lb a.i./ animal) a (mg a.i./

ft 2 cow hide) b Fish Aquatic

Invertebrates

and Plants Texas: Dip Vat Application (42% flowable concentrate) Single 0.027 272 0.02 0.008 0.013 0.008 0.008 Rest of U.S.: Back Rubber Applicatio n (11.6% emulsifiable concentration) Single 0.01 101 0.027 0.004 0.007 0.004 0.004

a Table 2-1

b See Table 4-12 for calculation

c Table 4-1

d EEC per treated cow wading into a body of water that is 1 acre, 6 feet deep; calculated using equation in Table 4-4



### Table 4-9. Equation for Calculating Estima ted Environmental Concentration (EEC) per Treated Cow Wading into a 1 Acre, 6 foot Deep Body of Water a 

### ( i.e. , EEC/Cow) 12

EEC/cow = surface area of cow in square feet a x μg coumaphos per square feet of hide b x fraction of cow surface submerged in a body of water containing non-target organisms ( i.e. , 0.25) c
x wash-off fraction

x 2.205 x 10 -9 lb/μg x 61 μg/L concentration in pond per lb loading

a The surface area of a 1000-2000 lb cow is about 45 sq ft, based on communication from Jerry Breiter of the U.S.

Hide, Skin and Leather Association (USHSLA) (USEPA, 1996).

b see Table 4-12 for calculation

c A cow will generally enter water up to the hair break line, which is a clearly visible line on the sides of the cow,

where the types of hair change visibly. According to th e USHSLA, this means that about 25% of the skin surface is submerged (USEPA, 1996).

12 For details on calculation of EEC, see USEPA, 1996.

### 30 Table 4-10. Pore Water Estimated Environmenta l Concentrations (EECs) from Wash-Off

from the Skin of Treated Livest ock That Enter Bodies of Water

Maximum Application Rate Wash-Off

Fraction c Peak EEC (parent+oxon) /cow d,e (μg/L) (Coumaphos + Coumaphoxon) Chronic EEC (parent+oxon) /cow d,e (μg/L) (Coumaphos + Coumaphoxon) Type (lb a.i./ animal) a (mg a.i./

ft 2 cow hide) b Benthic Invertebrates

Texas: Dip Vat Application (42% flowable concentrate) Single 0.027 272 0.02 0.005 0.007 Rest of U.S.: Back Rubber Applicatio n (11.6% emulsifiable concentration) Single 0.01 101 0.027 0.003 0.003

a Table 2-1

b See Table 4-12 for calculation

c Table 4-1

d EEC per treated cow wading into a body of water that is 1 acre, 6 feet deep; calculated using equation in Table 4-4

e = surface water EEC from Table 4-8 / ratio of surface water EEC (parent+oxon) : pore water EEC (parent+oxon) from Table

4-7



### 4.3 Terrestrial Exposure

4.3.1 Birds and Mammals

Birds may be exposed to coumaphos via contact with/ingestion of hair and skin debris from
treated cattle and/or contaminated soil and f eed in and around treatment areas. Additionally, birds and mammals may be exposed to coumap hos via ingestion of coumaphos-contaminated bird carcasses, ingestion of food items on land receiving manure from CAFOs, and ingestion of
contaminated fish.

4.3.1.1 Contact with/Ingestion of Ha ir and Skin Debris from

Treated Cattle and/or Contaminated Soil and Feed in and around Treatment Areas (Primary Exposure)

Evidence for avian exposure via contact with/ingesti on of hair and skin debris from treated cattle
and/or contaminated soil and feed in and around treatment areas has been confirmed by a pilot field study submitted to the Agency (MRID 42512604) . Eight cattle in one pen were sprayed with coumaphos (2 lb a.i. in 50 gal water) un til each individual was thoroughly soaked. After treatment, coumaphos residues were detected in soil samples, cow feces, cow hair samples, and stomach contents of cowbirds (see Table 4-11 for residues in soil, hair, and feces). Brain cholinesterase activity was inhib ited 2-59% in 13 of 19 cowbirds examined. Thirty-four bird species were recorded within 200 m of the treatment site, with six species observed on the ground in the pen. Based on severa l counts, 290 birds were estimated to frequent the 3.7-hectare pen. The results from treating only 8 cows in one pen were too limited in scope to draw any major conclusions. However, the study did indicate th at a variety of birds ar e likely to be present at treatment sites and that they may be exposed to coumaphos residues fr om soil from cowpens, bovine feces, and bovine hair. The study also included information re garding bird use of feedlots and pastures, and species likely to be expose d, ranked in order of potential exposure in
feedlots. Due to its close association with cattle, the black-billed magpie was listed as the species most likely to be exposed.

### 31 Table 4-11. Coumaphos Residues (Mean ± SD ppm) for Pilot Field Study (MRID 42512604)

Source Pre-Treatment Hours Post-Treatment

1 24 72 Soil from cowpens 50.7 ± 21.3 (n = 8) 344 ± 251 (n = 16) 114 ± 137 (n = 8) 142 ± 153 (n = 8)

Bovine hair 0.164 ± 0.126 (n = 8) 1,228 ± 158 (n = 8) 853 ± 250 (n = 8) 370 ± 98 (n = 8)

Bovine feces* 0.0962 ± 0.1847 (n = 8) 0.0791 ± 0.1346 (n = 7) 0.0088 ± 0.0080 (n = 8) ≤ 0.0015 ± 0 (n = 8) * collected via rectal palpation



### Mass of coumaphos per square foot of cow hide was used a conservative dose-based estimated exposure concentration (EEC) fo r characterizing exposure of bi rds to coumaphos via contact with/ingestion of hair and skin debris from treated cattle and/or contaminated soil and feed in and around treatment areas ( Table 4-12 ). Dose-based EECs were calculated for the maximum single application rates based on information from labels ( i.e. , Texas, dip vat application: 0.027 lb a.i./animal; rest of U.S., back rubber applica tion: 0.01 lb a.i./animal) and information from the U.S. Hide, Skin and Leather Association (USHSLA).

Mean residues of coumaphos detected in bovine hair (a surrogate for potential contaminated food items) 1, 24, and 72 hours post-treatment as repor ted in the pilot field study (MRID 42512604) – 1228, 853, and 370 mg a.i./kg-diet, respectively – were used as dietary-based EECs for characterizing exposure of birds to coumaphos via contact with/ingestion of hair and skin debris
from treated cattle and/or contaminated so il and feed in and around treatment areas.

Table 4-12. Dose-Based Estimated Environm ental Concentrations (EECs) for Treated

Cow Hide

Maximum Application Rate Cow Hide Surface Area a (ft 2 ) Dose-Based EEC (mg a.i./ft 2 cow hide) Type (lb a.i./animal) (mg a.i./animal) Texas: Dip Vat Application (42% flowable concentrate) Single 0.027 12,247 45 272 Rest of U.S.: Back Rubber Applicatio n (11.6% emulsifiable concentration) Single 0.01 4,536 45 101

a The surface area of a 1000-2000 lb cow is about 45 sq ft, based on communica tion from Jerry Breiter of the U.S.

Hide, Skin and Leather Association (USHSLA) (USEPA, 1996).



### 4.3.1.2 Ingestion of Coumaphos-Contaminated Bird Carcasses (Secondary Exposure)

Dose- and dietary-based EECs for secondary expo sure of birds and mammals via ingestion of coumaphos-contaminated bird carcasses were ca lculated. Both types of EECs required the
estimation of the concentration of coumaphos in a bird carcass since no empirical residue data
are available.

The concentration of coumaphos in a bird carcas s (mg a.i./g-bw) was assumed to be equivalent to potential coumaphos intake on a single day (mg a. i./g-bw/day) by the species most likely to be exposed to coumaphos according to the pilot field study (MRID 42512604), the black-billed magpie. In turn, the potential coumaphos inta ke on a single day by a black-billed magpie was

### 32 assumed to represent the maximum concentration in the carcass ( i.e. , there is no longer term accumulation of residues in the tissue beyond what would be expected from intake on a single day). The concentrations of coumaphos in food items –1228, 853, and 370 mg a.i./kg-diet = 1.228, 0.853, and 0.370 mg a.i./g-diet – were assumed to be equivalent to the mean residues of coumaphos detected in bovine hair (a surroga te for potential contaminated food items) 1, 24, and 72 hours post-treatment, respectively, as re ported in the pilot field study (MRID 42512604). Using the formulas and additional assumptions provided in Table 4-13 , the concentrations of coumaphos in a black-billed magpie carcass we re estimated to range from 0.039 to 0.129 mg a.i./g-bw.

Dose-based EECs for secondary exposure of bi rds and mammals via ingestion of coumaphoscontaminated bird carcasses were assumed to be equivalent to the potential coumaphos intake on a single day ( i.e. , mg a.i./g-bw/day) by a red-tailed ha wk and a red fox, respectively. These two predators/scavengers were chosen because they are representative of a mammal and bird, respectively, that could be exposed secondarily to coumaphos via ingestion of contaminated bird carcasses. Assumptions and formulas used to calculate potential daily coumaphos intake by
birds and mammals via seconda ry exposure are provided in Table 4-13 . Dosed-based EECs as coumaphos intake for this route of expos ure were estimated to range from 4.16 x 10 -6 

### to 1.38 x

10 -5 

### mg a.i./g-bw/day and 1.17 x 10 -5 

### to 3.87 x 10 -5 

### mg a.i./g-bw/day for the red fox and redtailed hawk, respectively. Assuming no degradat ion of coumaphos in the contaminated bird carcass prior to consumption by the predator/scavenger ( e.g. , red-tailed hawk and red fox, respectively), dietary-based EECs for secondary exposure of birds and mammals via ingestion of coumaphos-contaminated bird carcasses were es timated to range from 0.039 to 0.129 mg a.i./gdiet, the range of estimated concentrations of coumaphos in a bird carcass.

### 33 Table 4-13. Assumptions and Formulas Used to Calculate Coumaphos Intake (CI) via (a) Primary and (b) Secondary Exposure

a) Primary exposure a Assumptions

 The black-billed magpie, the species most likely to be e xposed to coumaphos according to the pilot field study (MRID 42512604), is the consuming individual.

 The weight of a black-billed magpie ( Pica pica ) is 186 g (Dunning, 1984).

 The concentrations of coumaphos in food items –1228, 853, and 370 mg a.i./kg-diet = 1.228, 0.853, and 0.370 mg a.i./g-diet – are the mean residues of coumaphos detected in bovine hair (a surrogate for potential contaminated food items) 1, 24, and 72 hours post-treatment, respectively, as reported in the pilot field study (MRID 42512604).

 Bovine hair is 100% dry material. Thus, food dry weight is equivalent to food wet weight.

 The black-billed magpie consumes 100% of its diet as food items contaminated with coumaphos at a concentration of 1.228, 0.853, or 0.370 mg a.i./g-diet.

Formulas

FI b (g dry-wt/day) (black-billed magpie) = 0.648 * Wt (g) 0.651 = 0.648 * (186) 0.651 = 19.5 g dry-wt/day

FI (g wet-wt/day) (black-billed magpie) = FI (g dry-wt/day) (black-billed magpie) = 19.5 g wet-wt/day

CI (mg/g-bw/day) (black-billed magpie) = FI (g wet-wt/day) (black-billed magpie) * Coumaphos dietary concentration ( mg a.i./gdiet) Wt(g) = (19.5 * [0.370, 0.853, or 1.228]) / 186

= 0.039, 0.089, or 0.129 mg a.i./g-bw/day

Where:
FI = food intake CI = coumaphos intake Wt = weight Coumaphos dietary concentration (mg/g-diet) = 1.450 mg a.i./g-diet d
b) Secondary exposure e Assumptions

For mammals: For birds:

 The red fox ( Vulpes vulpes ) is the consuming
individual.

 The weight of a red fox is 4.5 kg = 4500 g (USEPA, 1993b)

 The daily intake rate of a red fox is 0.16 g drywt/g-bw (USEPA, 1993b).  The red-tailed hawk ( Buteo species) is the consuming individual.

 The weight of a red-tailed hawk is 1.1 kg = 1100 g (USEPA, 1993b)

 The daily intake rate of red-tailed hawk is 0.11 g dry-wt/g-bw (USEPA, 1993b).

For birds and mammals:

### 34  A bird carcass is 67% water (USEPA, 1993b).

 A red fox/red-tailed hawk consumes 100% of its diet as bird carcasses contaminated with coumaphos at a concentration of 0.129, 0.089, or 0.039 mg a.i./g-bw/day (calculated in (a)).

 There is no degradation of coumaphos in a bird carcass prior to consumption by a red fox/red-tailed hawk.

Formulas

FI (g wet-wt/day) = FI (g dry-wt/day) / 0.33

FI (g wet-wt/day) (red fox) = 0.16/0.33 = 0.48 g wet-wt/day FI (g wet-wt/day) (red-tailed hawk) = 0.11/0.33 = 0.33 g wet-wt/day

CI (mg/g-bw/day) = FI (g wet-wt/day ) * Coumaphos dietary concentration ( mg a.i./g-diet) Wt(g)

CI (mg/g-bw/day) (red fox) = (0.48 * [0.039, 0.089, or 0.129])/4500

= 4.16 x 10 -6 , 9.49 x 10 -6 , or 1.38 x 10 -5 mg a.i./g-bw/day CI (mg/g-bw/day) (red-tailed hawk) = (0.33 * [0.039, 0.089, or 0.129])/1100

= 1.17 x 10 -5 , 2.67 x 10 -5 , or 3.87 x 10 -5 mg a.i./g-bw/day

Where:
FI = food intake CI = coumaphos intake Wt = weight Coumaphos dietary concentration (mg/g-diet) = 0.152 mg a.i./g-diet

a ingestion of contaminated food items

b equation for all birds (USEPA, 1993b, pg. 3-4)

c for females (Dunning, 1984)

d highest coumaphos residue detected in potential contaminated food items ( e.g. , soil, hair, feces) as reported in the

pilot field study (MRID 42512604)

e ingestion of coumaphos-contaminated bird carcasses



### 4.3.1.3 Ingestion of Food items on Land Receiving Manure from

CAFOs

EECs for ingestion of food items on land receivi ng manure from CAFOs were calculated using
the T-REX model 13 

### (v1.5.2; June 6, 2013), a Tier 1 mode l for screening-level assessments of pesticides. T-REX estimates terrestrial animal exposure values resulting from possible dietary ingestion of pesticide residues present on non-food and food items. The T-REX model determines (1) EECs for birds and mammals and (2) risk to birds and mammals via calculation of risk quotients (RQs). In all sc reening-level assessments, the organisms are assumed to consume
100% of their diet as one f ood type. EECs in terms of LD 50 

### /ft 2 

### and associated RQs for broadcast granular applications were deemed to be most applicable to exposure vi a ingestion of food items on land receiving manure from CAFOs.

Input parameters for broadcast granular app lications include a maxi mum application rate, number of applications, applicati on interval, and definitive acute LD 50 

### toxicity endpoints for birds and mammals ( Table 4-14 ).

13 http://www.epa.gov/oppefed1/models/terrestrial/index.htm

### 35 Table 4-14. Input Parameters for T-REX Mode ling of Broadcast Granular Applications (Surrogate for CAFO Manure Applied to Land)

Source of Exposure Input Parameters

Maximum

Single Application

Rate a (lb a.i./A) Maximum

Annual

Number of Applications a Other Parameters

Texas: Spray Application (42% flowable concentrate)

Avian LD 50 = 2.4 mg/kg-bw (bobwhite quail; MRID 00112843)

Mammalian LD 50 = 17 mg/kg-bw (rat; MRID 00110597) CAFO manure applied to land No incorporation into
soil 0.015 1

Incorporation into soil within a day 0.009 1

Rest of U.S.: Back Rubber Application (11.6% emulsifiable concentration)

CAFO manure applied to land No incorporation into
soil 0.0092 1

Incorporation into soil within a day 0.0051 1

a Table 4-2



### Results of T-REX modeling of coumaphos EECs in terms of LD 50 

### /ft 2 

### from application of CAFO manure to land are provided in Tables 4-15

.

Table 4-15. Avian and Mammalian Estimate d Exposure Concentrations (EECs) for Application of CAFO Manure to Land

Source of Exposure EEC: LD 50 /ft 2 (mg a.i./ft 2 ) Texas: Spray Application (42% flowable concentrate)

CAFO manure applied to land No incorporation into soil 0.16 Incorporation into soil within a day 0.09 Rest of U.S.: Back Rubber Applicatio n (11.6% emulsifiable concentration)

CAFO manure applied to land No incorporation into soil 0.10 Incorporation into soil within a day 0.05



### 4.3.1.4 Ingestion of Contaminated Fish

EECs for ingestion of contaminated fi sh were calculated using KABAM (K OW 

### (based) Aquatic BioAccumulation Model; v. 1.0; April 9, 2009 ). KABAM estimates pot ential bioaccumulation of hydrophobic organic pesticides in freshwater aquatic food we bs and subsequent risks to mammals and birds via consumption of contaminat ed fish. KABAM is composed of two parts: 1) a bioaccumulation model estima ting pesticide concentrations in aquatic organisms and 2) a risk component translating exposur e and toxicological effects of a pesticide into risk estimates for mammals and birds consuming contaminated fish. The bioaccumulation portion of KABAM is based on an aquatic food web bioaccumula tion model published by Arnot and Gobas (2004). The bioaccumulation portion of KABAM relies on a pesticide’s octanol-water partition coefficient (K OW 

### ) to estimate uptake and elimination cons tants through respiration and diet of aquatic organisms in different tr ophic levels. Pesticide tissue conc entrations in aquatic organisms are calculated for different trophic levels of a f ood web through diet and re spiration. In the risk

### 36 component of KABAM, pesticide co ncentrations in aquatic organisms are used to estimate doseand dietary-based exposures and associated ri sk quotients for mammals and birds consuming aquatic organisms.

Input parameters for KABAM include Log Ko w (=4.3), Koc (=5904 L/kg oc), a pore water EEC, a water column EEC, rate consta nts for various tropic levels ( e.g. , default metabolism rate constant, Km = 0), and definitive toxicity endpoints for birds and mammals (see Appendix B,

Table B-1 ). For runoff, EECs for the scenario s that yielded the highest values ( i.e. , Texas: BSSTurf, runoff from unregulated small CAFO; rest of the U.S.: PA Turf, runoff from unregulated small CAFO) were use d. For wash-off from treated livestock that enter bodies of water, this analysis was conducted using th e EEC for wash-off fraction 0.02 (Texas) or 0.027 (rest of the U.S.) and 100 cows entering a body of water. The upper limit of 100 cows was selected based on literature indicating that a 6 fo ot deep, 1 acre farm pond would be suitable for watering 100 cows (Bray, 2013).

Results indicated RQ exceedances so model inputs were refined to more accurately reflect the fast elimination of coumaphos in fish as documented in the BCF study (MRIDs 00115168 and 00150619). Specifically, the fish BCF study shows that 95% of accumulated coumaphos is depurated within 24 hours of fish being place in clean water. Raw data from the BCF study was
used to calculate a fish Km of 0.936/day. This Km was used as an input for small, medium, and large fish, and KABAM was allowed to cal culate the remaining rate constants ( e.g. , uptake an elimination constants through diet and respiration) for fish.

4.3.2 Terrestrial (Upland and Semi-Aquatic) Plants

Terrestrial (upland and semi-aqua tic) plants could be exposed to coumaphos via uptake from CAFO manure applied to land and uptake from soil receiving runoff from land to which manure from CAFOs has been applied.

EECs for exposure via uptake from soil receivi ng runoff from land to which manure from CAFOs has been applied were calculate d using TerrPlant (v1.2.2; October 29, 2009) 14



### . TerrPlant, a Tier 1 model for screening-level asse ssments of pesticides, is used to estimate exposure to terrestrial plants from single pes ticide applicatio ns; the model does not consider exposures to plants from multiple pesticide a pplications. TerrPlant determines (1) EECs in runoff and in spray drift and (2) risk to non-li sted and listed species of monocots and dicots inhabiting dry (upland) and semi -aquatic areas via calculation of risk quotients (RQs).

Input parameters for TerrPlant include maximum single application rate, incorporation depth (1 inch; default), runoff fraction (2% based on the wa ter solubility of coumaphos – 20 mg/L), spray drift fraction, and definitive toxicity endpoint s from seedling emergence and vegetative vigor studies ( Table 4-16 ). Given that exposure via this pa thway includes runoff only, a spray drift
fraction of 0% was assumed. EECs used to evaluate potential risk to terr estrial plants for runoff from land to which manure from CAFOs has been applied are provided under the column titled
“Runoff EECs” in Table 4-17

.

14 http://www.epa.gov/oppefed1/models/terrestrial/index.htm

### 37 EECs for the exposure via uptake from CAFO ma nure applied to land were assumed to be equivalent to application rates calcu lated for unincorporated manure in Table 4-2 and are provided under the column titled “Direct Application EEC” in Table 4-17

.

Table 4-16. Input Parameters for TerrPlant Modeling

Source of Exposure Input Parameters Application Rate (lb a.i./A) Other Parameters

Texas: Spray Application (42% flowable concentrate)

Incorporation depth = ≤ 1 inch
Runoff fraction = 2% Spray drift fraction = 0%

SE endpoints: None a VV endpoints: None a Runoff from land to
which CAFO manure has been applied No incorporation into
soil 0.015

Incorporation into soil within a day 0.009

Rest of U.S.: Back Rubber Applicatio n (11.6% emulsifiable concentration)

Runoff from land to
which CAFO manure has been applied No incorporation into
soil 0.0092

Incorporation into soil within a day 0.0051

SE = seedling emergence; VV = vegetative vigor

a The are no toxicity data that are specific to coumaphos and suitable for calculation of RQs.



### Table 4-17. Terrestrial (Upland and Semi -aquatic) Plant Estimated Exposure Concentrations (EECs) for CAFO Manure Applied to Land

Source of Exposure Application

Rate a Direct Application

EEC c (lb a.i./A) Runoff EEC b (lb a.i./A)

All Areas Dry (Upland)

Areas Semi-Aquatic

Areas Texas: Spray Application (42% flowable concentrate)

CAFO manure applied to land No incorporation
into soil 0.015

0.015 0.0003 0.003

Incorporation into soil within a day 0.009 0.00018 0.0018

Rest of U.S.: Back Rubber Applicatio n (11.6% emulsifiable concentration)

CAFO manure applied to land No incorporation
into soil 0.0092

0.0092 0.000184 0.00184

Incorporation into soil within a day 0.0051 0.000102 0.00102

a From Table 4-2

b From TerrPlant

c assumed to be equivalent to application rates calculated for unincorporated manure



### 4.3.3 Honey Bees (In-Hive Use)

Honey bees may be exposed to coumaphos via im pregnated strips placed in hives to control varroa mites and hive beetles. Data on coumapho s residues (mg/kg) detected in bees, wax, and queen cells from hives with coumaphos-impregna ted strips are available from open literature study E066848 as identified via ECOTOX 15 

### ( Table 4-18 ). The former study (E066848), which was classified as “qualitative” for use in the assessment (see Section 5.2.3 for rationale), described two separate experiments with coumaphos. In one experiment, colonies received

15 http://cfpub.epa.gov/ecotox/

### 38 plastic strips containing no coumaphos (control), a low dose of coumaphos ( i.e. , 1⁄4 coumaphosimpregnated strip per frame in the starter colonies and 1⁄4 strip per mating nuc), or a high dose of coumaphos ( i.e. , 1⁄2 coumaphos-impregnated strip per frame in starter colonies and 1⁄2 strip per mating nuc). In the second experiment, colonies received hanging plas tic strips containing no coumaphos (control), 3 coumaphos-impregnated stri ps adjacent to cell frames but not touchingthe cell frames, 3 coumaphos-impregnated strips adjacent to cell frames, or 3 coumaphosimpregnated strips cut up and attached directly to each cell bar (1⁄2 strip per bar). Concentrations in bees, wax and queen cells of hives treated with coumaphos-impregnated strips ranged from 0.83-23.26, 12.69-120, and 8.11-237 mg/kg, respectively ( Table 4-18 ).

Table 4-18. Coumaphos Residues in Samples of Bees, Wax, and Queen Cells from Hives Treated with Coumaphos-Impregnated Strips a

Sample type Treatment Pre-Treatment Concentration (mg/kg) Post-Treatment Concentration (mg/kg) Experiment #1

Bee Control b < Level of detection 0.13

Low c < Level of detection 0.83 High d 1.54 6.47

Wax Control b < Level of detection 0.17

Low c 0.30 49.7 High d 0.36 120

Queen cells Control b Not applicable < Level of detection

Low c 181 High d 237 Experiment #2

Bee Control b

Did not measure 0.57 2 strips attached e 3.36 2 strips adjacent f 23.26 2 strips not touching g 9.95

Wax Control b

Did not measure <LOD 2 strips attached e 12.69 2 strips adjacent f 22.22 2 strips not touching g 12.85

Queen cells Control b

Did not measure NA 2 strips attached e 91.93 2 strips adjacent f 28.17 2 strips not touching g 8.11

a Source of data: Open literature study E066848 as identified via ECOTOX

b plastic strips containing no coumaphos

c 1⁄4 coumaphos-impregnated strip per frame in the starter colonies and 1⁄4 strip per mating nuc

d 1⁄2 coumaphos-impregnated strip per frame in starter colonies and 1⁄2 strip per mating nuc

e 3 coumaphos-impregnated strips cut up and attach ed directly to each cell bar (1⁄2 strip per bar)

f 3 coumaphos-impregnated strips adjacent to cell frames

g 3 coumaphos-impregnated strips adjacent to cell frames but not touching the cell frames



### In addition, data for coumaphos residues in comb wax, stored pollen, and live bees as well as coumaphos oxon residues in wax from a broad su rvey of pesticide residues sampled from
commercial bee hives in North Am erica are available (MRID 49497801; Table 4-22 ). Concentrations of coumaphos in wax, polle n, and bees ranged from 0.001-91.9, 0.001-5.83, and 0.001-0.762 mg/kg, respectively, and concentration of coumaphos in wax ranged from 0.0013- 1.3 mg/kg.

### 39 Table 4-22: Summary of Coumaphos Detections in Samples from North American Honey

Bee Colonies a

Sample Type Detects (%) Number

of Samples Analyzed Detections (mg/kg) High Low Median 90%

tile 95%

tile Mean SEM LOD

Coumaphos

Wax 254 (98.1) 259 91.9000 0.0010 1.2400 6.8750 11.3400 3.30040 0.49980 0.0010 Pollen 263 (75.1) 350 5.8280 0.0010 0.0131 0.5184 0.8920 0.1804 0.0330 0.0010 Bees 84 (60.0) 140 0.7620 0.0010 0.0080 0.1187 0.1562 0.0504 0.0135 0.0010 Coumaphos oxon

Wax 187 (98.9) 208 1.3000 0.0013 0.0561 0.1842 0.2698 0.1027 0.0125 0.0050 LOD = level of detection; SEM = standard error of the mean

a Source of data: MRID 49497801

### 40 

## 5 Effects Characterization

Data are obtained from registrant-submitted studies or from open literature studies identified by

ECOTOX 16 

### to characterize the effects of coumaphos to non-target organisms. Additional effects characterization is provided by reviews of reported incident s involving use of coumaphos.

A data call-in (DCI) was issued for two toxici ty studies after the 2008 problem formulation:

 850.4400 – Aquatic Plant Toxicity Test

 850.5400 – Algal Toxicity

The registrant subsequently submitted a Tier II aquatic vascul ar plant study with Lemna gibba (MRID 48322801) and a Tier II aquatic non-vas cular plant study with the green alga Pseudokirchneriella subcapitata (MRID 48322802). The study with L. gibba yielded an EC 50 

### of 166 μg a.i./L and a NOAEC of 166 μg a.i./L an d was classified as “supplemental” due to a guideline deviation ( i.e. , a the number of plants per replicat e was lower than recommended); the study with P. subcapitata was classified as “invalid” because the solvent had a stimulatory effect that could have masked the true effects of coumaphos. An additional aquatic non-vascular plant study for coumaphos was not requested based on an analysis presented in an EFED memo indicating that aquatic non-vascular plant toxicity da ta for a surrogate organophosphate
insecticide could be used to characterize the toxic ity of coumaphos to aquatic non-vascular plants (DP 406398, October 31, 2012; see Section 5.1.6 for additional details).

There are several open lite rature studies on th e effects of coumaphos to b ees that are used in this assessment (see Table 5-6 ). Other open literature studies also referenced coumaphos, but these
are not included in this assessm ent because: the reported toxicity endpoints are less sensitive than those from registrant-submitted studies; the information is not appropriate for inclusion for a variety of reasons including the reported endpoint is not comparable to a guideline endpoint; or the reported endpoint is not conve rtible to units used in risk assessment models. Coumaphos studies that are found in the open l iterature and passed the initial sc reen but were not used in the assessment are provided in Appendix C

.

5.1 Effects to Aquatic Organisms

Summaries of data used to characterize the e ffects of coumaphos to aquatic organisms are provided in Table 5-1 . The most sensitive definitive toxicity endpoints used in RQ calculations
are bolded.

5.1.1 Freshwater Fish

Based on studies with bluegill sunfish, lake tr out, walleye, channel catf ish, cutthroat trout, rainbow trout, and largemouth bass, coumaphos is moderately to highly toxic to freshwater fish
on an acute basis.

16 http://cfpub.epa.gov/ecotox/

### 41 In studies with bluegill sunfish, lake trout, wa lleye, channel catfish, cutthroat trout, rainbow trout, and largemouth bass (MRID 40098001), LC 50 

### ’s ranged 340 to 1100 μg a.i./L. No sublethal effects were specified in these studies.

In a second study with bluegill sunfish (MRID 00112840), the LC 50 

### was 5000 μg a.i./L, and the
sublethal effect of erratic sw imming was noted. In a second study with rainbow trout (MRID 00112840), the LC 50 

### was 5900 μg a.i./L, and sublethal e ffects including erratic swimming, loss of reflex, and discolor ation were observed.

In an early life-stage study with rainbow trout (MRID 43066301), the NOAEC of 11.7 μg a.i./Lwas based on the most sensitive endpoints of length and weight (day 62). However, day 36 posthatch survival and length were also affected at ≥ 96.1 μg a.i./L, and day 62 post-hatch survival
was affected at ≥ 48.4 μg a.i./L.

Since the freshwater fish chronic toxicity endpoint of 11.7 μg/L (rainbow trout; MRID 43066301) was not generated using the most acutely sensitive freshwater fish ( i.e. , bluegill sunfish), a chronic toxicity endpoint for blueg ill sunfish of 4.4 μg/L was calculated using the acute toxicity endpoint for bluegill sunfish and an acute to chronic ratio (ACR) for rainbow trout (see Table 5-1 for calculation).

5.1.2 Estuarine/Marine Fish

Based on an acute toxicity study with sheep shead minnow, coumaphos is highly toxic to
estuarine/marine fish. The LD 50 

### for this study (MRID 40228401) was 280 μg a.i./L; sublethal effects were not specified.

No data are available for the chro nic toxicity of coumaphos to estu arine/marine fish. Therefore, a chronic toxicity endpoint for es tuarine/marine fish of 3.6 μg/L was calculated using the acute toxicity endpoint for sheepshead minnow and an ACR for freshwater fish ( i.e. , rainbow trout) (see Table 5-1 for calculation).42Table 5-1. Endpoints Used to Characterize the Effects of Coumaphos to Aquatic OrganismsAssessmentEndpointMeasurementEndpoint% a.i.SpeciesToxicity Endpointsa,b(Effects) & Acute ToxicityClassification (if applicable)Source &ClassificationSurvival, growth, andreproduction offreshwater fish(surrogate for aquaticphase amphibians)Most sensitivefreshwater fish acuteLC5095 Bluegill sunfish(Lepomismacrochirus)96-hr LC50=340μg a.i./LHighly toxicMRID 40098001Mayer andEllersieck (1996)95 Lake trout(Salvelinusnamaycush)96-hr LC50(95% C.I.) = 593 (416-846) μg a.i./LHighly toxicMRID 40098001Mayer andEllersieck (1996)95 Walleye(Stizostedionvitreum vitreum)96-hr LC50(95% C.I.) = 780 (645-943) μg a.i./LHighly toxicMRID 40098001Mayer andEllersieck (1996)95 Channel catfish(Ictaluruspunctatus)96-hr LC50(95% C.I.) = 840 (620-1140) μg a.i./LHighly toxicMRID 40098001Mayer andEllersieck (1996)95 Cutthroat trout(Salmo clarki)96-hr LC50(95% C.I.) = 862 (645-1150) μg a.i./LHighly toxicMRID 40098001Mayer andEllersieck (1996)95 Rainbow trout(Salmo gairdneri)96-hr LC50=898μg a.i./LcHighly toxicMRID 40098001Mayer andEllersieck (1996)95 Largemouth bass(Micropterussalmoides)96-hr LC50(95% C.I.) = 1100 (1000-1200) μg a.i./LModerately toxicMRID 40098001Mayer andEllersieck (1996)99.6 Bluegill sunfish(Lepomismacrochirus)96-hr LC50(95% C.I.) = 5000 (4000-6300) μg a.i./LProbit slope (95% C.I.) = 4.4 (2.7-6.0)(0, 10, 20, 40, 70, 90, and 100% mortality at 1500,2200, 3200, 4700, 6900, 10000, and 15000 μg a.i./L;sublethal effects: erratic swimming)Moderately toxicMRID 00112840Acceptable99.6Rainbow trout(Oncorhynchusmykiss)96-hr LC50(95% C.I.) = 5900 (5100-6900) μg a.i./LProbit slope (95% C.I.) = 13.0 (5.4-20.6)(0, 10, 80, 100, and 100% mortality at 3200, 4700,6900, 10000 and 15000 μg a.i./L; sublethal effects:erratic swimming, loss of reflex, and discoloration)Moderately toxicMRID 00112840AcceptableNA Bluegill sunfish Estimated chronic NOAEC(bluegill sunfish)NA43AssessmentEndpointMeasurementEndpoint% a.i.SpeciesToxicity Endpointsa,b(Effects) & Acute ToxicityClassification (if applicable)Source &ClassificationMost sensitivefreshwater fish chronicNOAEC(Lepomismacrochirus)= Acute LC50(bluegill sunfish)/ ACR(rainbow trout)= 340 μg/L / 77=4.4μg/LWhere:ACR(rainbow trout)= Acute LC50(rainbow trout)/ Chronic NOAEC(rainbow trout)= 898 μg/L / 1.6 μg/L= 7796.2(TGAI)99.1(Radiolabeled)Rainbow trout(Oncorhynchusmykiss)Early life-stage62-day NOAEC =11.7μg a.i./L62-day LOAEC = 24.6 μg a.i./L(based on most sensitive endpoints of length andweight; day 36 post-hatch survival and length alsoaffected at≥96.1 μg a.i./L; day 62 post-hatchsurvival also affected at≥48.4898 μg a.i./L)MRID 43066301AcceptableSurvival, growth, andreproduction ofestuarine/marine fishMost sensitiveestuarine/marine fishacute LC5095 Sheepsheadminnow(Cyprinodonvariegatus)48-hr LC50=280μg a.i./L (nom)Highly toxicMRID 40228401Mayer (1986)Most sensitiveestuarine/marine fishchronic NOAECNA Sheepsheadminnow(Cyprinodonvariegatus)No dataEstimated chronic NOAEC(sheepshead minnow)= Acute LC50(sheepshead minnow)/ ACR(rainbow trout)= 280 μg/L / 77=3.6μg/LWhere:ACR(rainbow trout)= Acute LC50(rainbow trout)/ Chronic NOAEC(rainbow trout)= 898 μg/L / 1.6 μg/L= 77NASurvival, growth, andreproduction offreshwaterinvertebratesMost sensitivefreshwater invertebrateacute EC5097 Scud(Gammaruslacustris)96-hr LC50(95% C.I.) =0.074(0.059-0.092) μg a.i./L48-hr LC50(95% C.I.) = 0.14 (0.082-0.24) μg a.i./LVery highly toxicMRIDs 05009242and 40098001Supplemental(due to life stagetested – adultinstead ofimmature)44AssessmentEndpointMeasurementEndpoint% a.i.SpeciesToxicity Endpointsa,b(Effects) & Acute ToxicityClassification (if applicable)Source &Classification95 Scud(Gammarusfasciatus)96-hr LC50(95% C.I.) = 0.15 (0.11-0.20) μg a.i./LVery highly toxicMRID 05017538Supplemental(due to life stagetested – adultinstead ofimmature)99.64(TGAI)98.9(Radiolabeled)Water flea(Daphnia magna)48-hr EC50(95% C.I.) = 0.192 (0.134-0.240) μg a.i./L(mm)dProbit slope (95% C.I.) = 2.7 (1.7-3.7)48-hr NOAEC < 0.106 μg a.i./L (mm)(30, 50, 65, 80, 85, and 100% immobility at 0.106,0.210, 0.310, 0.415, 0.523, and 0.614 μg a.i./L)Very highly toxicMRID 41778503Supplemental(due to life stagetested – adultinstead of < 24-hrold instar)99.64(TGAI)98.9(Radiolabeled)Scud(Gammaruslacustris)48-hr EC50(95% C.I.) = 0.224 (0.201-0.246) μg a.i./L (mm)Probit slope (95% C.I.) = 6.6 (5.0-8.3)48-hr NOAEC = 0.103 μg a.i./L (mm)(0, 25, 35, 55, 80, 95, 100, 100, 100, 100, 100, and100% immobility at 0.103, 0.154, 0.204, 0.255, 0.326,0.371, 0.408, 0.514, 0.610, 0.708, and 0.806 μg a.i./L)Very highly toxicMRID 41778504AcceptableMost sensitivefreshwater invertebratechronic NOAECNA Scud(Gammarusfasciatus)Estimated chronic NOAEC(G. lacustris)= Acute LC50(G. lacustris)/ ACR(D. magna)= 0.074 μg/L / 6=0.0127μg/LWhere:ACR(D. magna)= Acute EC50(D. magna)/ Chronic NOAEC(D. magna)= 0.192 μg/L / 0.0337 μg/L= 6NA99.1(Radiolabeled)Water flea(Daphnia magna)21-day NOAEC = 0.0337 μg a.i./L (mm)21-day LOAEC = 0.0758 μg a.i./L (mm)(NOAEC based on survival)MRID 43116601AcceptableSurvival, growth, andreproduction ofestuarine/marineinvertebratesMost sensitiveestuarine/marineinvertebrate acute EC50or LC5095 Pink shrimp(Penaeusduorarum)48-hr EC50= 2.0μg a.i./L (nom)Very highly toxicMRID 40228401Mayer (1986)95 Eastern oyster96-hr EC50= 290 μg a.i./L (nom) at221 ppt sal. and 9 °C96-hr EC50= 880 μg a.i./L (nom)at 23 ppt sal. and 9 °CMRID 40228401Mayer (1986)45AssessmentEndpointMeasurementEndpoint% a.i.SpeciesToxicity Endpointsa,b(Effects) & Acute ToxicityClassification (if applicable)Source &Classification(Crassostreavirginica)Highly toxicMost sensitiveestuarine/marineinvertebrate chronicNOAECNA Pink shrimp(Penaeusduorarum)Estimated chronic NOAEC(pink shrimp)= Acute LC50(pink shrimp)/ ACR(D. magna)= 2.0 μg/L / 6=0.3421μg/LWhere:ACR(D. magna)= Acute EC50(D. magna)/ Chronic NOAEC(D. magna)= 0.197 μg/L / 0.0337 μg/L= 6NASurvival, growth, andreproduction ofbenthic (sedimentdwelling)invertebratesMost sensitive bebenthic invertebrateacute EC50or LC50orsub-chronic NOAECNo dataMost sensitive benthicinvertebrate chronicNOAECNo dataSurvival, growth andreproduction ofaquatic plantsAquatic non-vascularspecies: Most sensitiveEC50No dataAquatic vascularspecies: Most sensitiveEC5095.7 Duckweed(Lemna gibba)Tier II7-dayEC50> 166 μg a.i./L (mm)7-day NOAEC =166μg a.i./L (mm)(no effects)MRID 48322801Supplemental(due to the numberof plants perreplicate beinglower thanrecommended)C.I. = confidence interval; NA = not applicableaBOLDvalues used in RQ calculationsbmm = mean-measured; nom = nominalcused to calculate freshwaterfish acute to chronic ratiodused to calculate freshwater invertebrate acute to chronic ratio

### 46 5.1.3 Freshwater Invertebrates

Based on studies with Gammarus lacustris

, Gammarus fasciatus , and Daphnia magna, coumaphos is very highly toxic to freshwat er invertebrates on an acute basis.

An acute study with the scud G. lacustris (MRID 05009242) yielded the most sensitive endpoint,

i.e. , LC 50 

### = 0.074 μg a.i./L. This study was classified as “supplemental” due to the life stage of the test organisms; adult indi viduals were used instead of immature individuals, which are recommended. A second study with G. lacustris (MRID 41778504), which is classified as “acceptable,” had an EC 50 

### of 0.224 μg a.i./L and a NOAEC of 0.103 μg a.i./L based on immobility.

An acute study with a nother species of scud, G. fasciatus (MRID 05017538), yielded an LC 50 

### of 0.15 μg a.i./L. This study was classified as “s upplemental” due to the life stage of the test organisms; adult individuals were used in stead of immature individuals, which are
recommended.

In the acute study with D. magna (MRID 41778503), the EC 50 

### was 0.192 μg a.i./L, and the NOAEC was less than the lowest concentration tested, ( i.e. , < 0.106 μg a.i./L). This study was classified as “supplemental” due to the life stage of the test or ganisms; adult individuals were
used instead of < 24-hour old indi viduals, which are recommended.

In the chronic study with D. magna (MRID 43116601), the NOAEC of 0.0337 μg a.i./L was
based on survival.

Since the freshwater invertebrate ch ronic toxicity endpoint of 0.0337 μg/L ( D. magna ; MRID 43116601) was not generated using the most acute ly sensitive freshwat er invertebrate ( i.e.

, G.
lacustris ), a chronic toxi city endpoint for G. lacustris of 0.0127 μg/L was calculated using the acute toxicity endpoint for G. lacustris and an ACR for D. magna (see Table 5-1 for calculation).

5.1.4 Estuarine/Marine Invertebrates

Based on studies with pink shrimp and Easter n oyster (MRID 40228401), c oumaphos is highly to very highly toxic to estuarin e/marine invertebrates on an acut e basis. These studies yielded

EC 50 

### endpoints of 2.0 and 290 μg a.i./L, respectively.

No data are available for the chro nic toxicity of coumaphos to es tuarine/marine invertebrates. Therefore, a chronic toxicity endpoint for estuarine/marine invertebrates of 0.3421 μg/L was calculated using the acute toxi city endpoint for pink shrimp and an ACR for freshwater invertebrates ( i.e.

, D. magna ) (see Table 5-1 for calculation).

5.1.5 Benthic (Sediment-Dwelling) Invertebrates

No data are available for the toxicity of coumaphos to benthic invertebrates.

### 47 5.1.6 Aquatic Plants

A Tier II study with Lemna gibba (MRID 43822801) submitted since the 2008 problem formulation yielded no eff ects resulting in an EC 50 

### and NOAEC of > 166 and 166 μg a.i./L, respectively. This study was classified as “s upplemental” due to the number of plants per replicate being lower than recommended.

No acceptable data are available for the toxicity of coumaphos to aquatic non-vascular plants. As noted previously, a study with P. subcapitata (MRID 48322802) submitted since the 2008 problem formulation was classified as “invalid” b ecause the solvent had a stimulatory effect that
could have masked the true effects of co umaphos. An EFED memo (DP 406398, October 31, 2012) proposed using data from a surrogate pest icide in lieu of requesting an additional nonvascular aquatic plant study. Sp ecifically, the memo noted that a quatic non-vascular plant data are available for the following organophosphate in secticides: chlorpyrifos, diazinon, dichlorvos, dicrotophos, dimethoate, EPN, fe nthion, naled, oxydemeton-methyl, phorate, and trichlorfon. Of the available data, naled is the most toxic to aqua tic non-vascular plants. Thus, toxicity data for naled ( Table 5-2 ) was used for characterizing the toxicity of coumaphos to aquatic non-vascular plants. The most sensitive definiti ve toxicity endpoints for naled ( i.e. , EC 50 

### = 24 μg a.i./L; NOAEC = 4.2 μg a.i./L) are bolded.

Table 5-2. Aquatic Plant T oxicity Profile for Naled

Species % a.i. Toxicity Values a Source &

Classification

Duckweed (Lemna gibba) 94.4 14-day EC 50 > 1800 μg a.i./L 14-day NOAEC < 1800 μg a.i./L MRID 42529601 Supplemental Blue-green algae ( Anabaena flos-aquae) 94.4 5-day EC 50 (95% C.I.) = 91 (15-7400) μg a.i./L 5-day NOAEC = 57 μg a.i./L MRID 42529604 Acceptable

Freshwater diatom ( Navicula pelliculosa) 94.4 5-day EC 50 (95% C.I.) = 24 (10-70) μg a.i./L 5-day NOAEC = 4.2 μg a.i./L MRID 42529603 Acceptable Green algae ( Selenastrum capricornutum) 94.4 5-day EC 50 (95% C.I.) = 40 (13-100) μg a.i./L 5-day NOAEC: Not reported MRID 42529605 Acceptable

Marine diatom ( Skeletonema costatum) 94.4 5-day EC 50 (95% C.I.) = 50 (24-100) μg a.i./L 5-day NOAEC = 6.3 μg a.i./L MRID 42529602 Acceptable

C.I. = confidence interval

a BOLD values used in risk characterization



### 5.2 Effects to Terrestrial Organisms

Summaries of data used to characterize the eff ects of coumaphos to terrestrial organisms are provided in Table 5-3 . The most sensitive definitive toxicity endpoints used in RQ calculations
are bolded.48Table 5-3. Endpoints Used to Characterize theEffects of Coumaphos toTerrestrial OrganismsAssessmentEndpointMeasurementEndpoint% a.i.SpeciesToxicity Endpoints1,2(Effects) & Acute Toxicity Classification(if applicable)Source &ClassificationSurvival, growth,and reproductionof birds(surrogate forreptiles andterrestrial-phaseamphibians)Most sensitive avianacute oral LD5098.25 Bobwhite quail(Colinusvirginianus)14-day LD50(95% C.I.)=2.4(1.1-3.3) mg a.i./kg-bw (nom)Probit slope (95% C.I.) = 4.3 (1.2-7.3)(0, 40, 100, 100, and 100% mortality at 2, 4, 8, 16, 32 mg a.i,/kgbw; all mortality occurred within the first 24 hours; sublethaleffects: fluffed feathers in some birds of the 2 mg a.i./kg-bwtreatment group; salivation, ataxia, wing drop, convulsions, andfluffed feathers in other treatment groups)Very highly toxicMRID 00112843Acceptable95 Ring-neckedpeasant(Phasianuscolchicus)14-day LD50(95% C.I.) = 7.94 (5.73-11.0) mg a.i./kg-bw (nom) –females(mortality 2-3 hr after treatment; remission took up to 14 days;sublethal effects: spraddle-legged walking, wing twitching,slowness, hypoactivity, ataxia, wing-drop, falling, nutation,prostration with wings spread, lacrimation, immobility, wing-beatconvulsions, and tetany appearing as soon as 90 minutes)Very highly toxicMRID 00160000Acceptable95 Mallard duck(Anasplatyrhynchos)14-day LD50(95% C.I.) = 29.8 (21.5-41.3) mg a.i./kg-bw (nom) -males(mortality 2-3 hr after treatment; remission took up to 14 days;sublethal effects: spraddle-legged walking, wing twitching,slowness, hypoactivity, ataxia, wing-drop, falling, nutation,prostration with wings spread, lacrimation, immobility, wing-beatconvulsions, and tetany appearing as soon as 40 minutes)Highly toxicMRID 00160000AcceptableMost sensitive aviansub-acute dietaryLC5098.25 Bobwhite quail(Colinusvirginianus)8-day LC50(95% C.I.) =82.1(67.6-99.7) mg a.i./kg-diet (nom)Probit slope (95% C.I.) = 6.6 (3.6-9.7)(0, 10, 20, 70, 100, 100, and 100%mortality at 30, 45, 68, 102,153, 230, and 345 mg a.i./kg-diet; sublethal effects: ataxia, wingdrop, convulsions, tremors, and diarrhea at≥68 mg a.i./kg-diet;decrease in body weights at 45-153mg a.i./kg-diet; concentrationdependent decrease in food consumption during the first 5 days forbirds on treated feed)Highly toxicMRID 00112843Acceptable95 Bobwhite quail(Colinusvirginianus)8-day LC50(95% C.I.) = 120 (104-139) mg a.i./kg-diet (nom)Probit slope (S.D.) = 7.348 (1.923)Highly toxicMRID 00022923Acceptable95 Japanese quail 8-day LC50(95% C.I.) = 225 (172-306) mg a.i./kg-diet (nom) MRID 0002292349AssessmentEndpointMeasurementEndpoint% a.i.SpeciesToxicity Endpoints1,2(Effects) & Acute Toxicity Classification(if applicable)Source &Classification(Coturnixjaponica)Probit slope (S.D.) = 4.652 (1.049)Highly toxicAcceptable95 Ring-neckedpeasant(Phasianuscolchicus)8-day LC50(95% C.I.) = 318 (227-364) mg a.i./kg-diet (nom)Probit slope (S.D.) = 7.228 (1.452)Highly toxicMRID 00022923Acceptable98.25 Mallard duck(Anasplatyrhynchos)8-day LC50(95% C.I.) = 402 (227-593) mg a.i./kg-diet (nom)Probit slope (95% C.I.) = 2.9 (1.7-4.2)(0, 0, 30, 50, 70, and 100% mortality at 50, 100, 200, 400, 800,and 1600 mg a.i./kg-diet; sublethal effects wing drop, salivationregurgitation, ataxia, nutation, and immobility at≥200 mg a.i./kgdiet; decrease in body weights from day 0 to day 5 at≥100 mga.i./kg-diet; concentration-dependent decrease in foodconsumption during the first 5 days for birds on treated feed)Highly toxicMRID 00112842Acceptable95 Mallard duck(Anasplatyrhynchos)8-day LC50(95% C.I.) = 709 (521-1032) mg a.i./kg-diet (nom)Probit slope (S.D.) = 1.981 (0.933)Moderately toxicMRID 00022923AcceptableMost sensitive avianchronic NOAECNo dataSurvival, growth,and reproductionof mammalsMost sensitivemammalian acuteLD50TGAI SpragueDawley rat(Rattusnorvegicus)Females LD50(95% C.I.) =17(14-22) mg/kg-bwMale LD50> 240 mg/kg-bw(Mortality: females – 0, 0, 70, and 100% mortality at 5, 10, 20,and 40 mg/kg-bw; males – 0, 0, 0, 0, and 10% mortality at 7.5, 15,30, 60, 120, and 240 mg/kg-bw; sublethal effects (not specified):females – 90, 100, 100, and 100% at 5, 10, 20, and 40 mg/kg-bw;males – 80, 100, 100, 100, 100, and 100% at 7.5, 15, 30, 60, 120,and 240 mg/kg-bw )Highly toxicMRID 00110597Most sensitivemammalian chronicNOAEC99 SpragueDawley rat(Rattusnorvegicus)Two-generation reproductionCholinesterase (ChE) inhibitionNOAEL = 1 mg/kg-diet (0.07 mg/kg-bw/day)LOAEL = 5 mg/kg-diet (0.30 mg/kg-bw/day)Systemic/reproductive toxicityNOAEC =25mg/kg-diet (1.79 mg/kg-bw/day)LOAEC > 25 mg/kg-diet (1.79 mg/kg-bw/day)(no effects)MRID 4306170150AssessmentEndpointMeasurementEndpoint% a.i.SpeciesToxicity Endpoints1,2(Effects) & Acute Toxicity Classification(if applicable)Source &ClassificationSurvival, growth,and reproductionof non-targetterrestrialinvertebratesMost sensitiveterrestrialinvertebrate (e.g.,honey bee) acuteLD50SeeSection 5.2.3Survival, growthand reproductionof terrestrial plantsSeedling emergence:Most sensitivemonocot and dicotEC25and NOAECNo dataVegetative vigor:Most sensitivemonocot and dicotEC25and NOAECNo dataNS = not specified; C.I. = confidence interval1BOLDvalues used in RQ calculations2nom = nominal

### 51 5.2.1 Birds

Based on studies with bobwhite quail, ring-neck ed peasant, and mallard duck, coumaphos is highly toxic to very highly toxic to birds on an acute oral basis.

In the acute oral study with bobwhite quail (MRID 00112843), the LD 50 

### was 2.4 mg a.i./kg-bw, and all mortality occurred within the first 24 hour s. Sublethal effects in the lowest treatment group of 2 mg a.i./kg-bw (100% survival) included fluffed feathers in some birds. Salivation, ataxia, wing drop, convulsions, and fluffed feathe rs were observed in the other treatment groups.

In acute oral studies with ring-necked peasant and mallard duck (MRID 01600000), the LD 50 

### ’s were 7.97 and 29.8 mg a.i./kg-bw, respectively. Mo rtality occurred within 2 to 3 hours after treatment, and remission took up to 14 days. Sublethal effects including spraddle-legged walking, wing twitching, slowness, hypoactivity, ataxia, wing-dr op, falling, nutation, prostration with wings spread, lacrimation, immobility, wi ng-beat convulsions, and tetany appeared as soon as 90 and 40 minutes after dosing in ring-necked peasants and malla rd ducks, respectively.

Based on studies with bobwhite quail, Japanese quail, ring-necked pheasant, and mallard duck, coumaphos is moderately to highly toxic to birds on a sub-acut e dietary basis.

In the sub-acute dietary study with bobwhite qua il that yielded the most sensitive endpoint (MRID 00112843), the LC 50 

### was 82.1 mg a.i./kg-diet. Sublet hal effects included ataxia, wing drop, convulsions, tremors, and diarrhea at ≥ 68 mg a.i./kg-diet and a decrease in body weights at 45-153 mg a.i./kg-diet. A con centration-dependent decrease in food consumption was also observed during the first 5 days for birds on treated feed.

In sub-acute dietary studies with bobwhite quail, Japanese quail, and mallard duck (MRID 00022923), the LC 50 

### ’s were 120, 225, and 709 mg a.i./kg-di et. Sublethal effects were not specified for these studies.

In another sub-acute dietary study with mallard duck (MRID 00112842), the LC 50 

### was 402 mg a.i./kg-diet. Sublethal effect s included wing drop, salivation, regur gitation, ataxia, nutation, and immobility at ≥ 200 mg a.i./kg-diet and a decrease in body weights from day 0 to day 5 at ≥ 100 mg a.i./kg-diet. A concentra tion-dependent decrease in food consumption was also observed during the first 5 days fo r birds on treated feed.

There are no data available for the chronic, repro ductive toxicity of coumaphos to birds. In the absence of data specific to coumaphos, avian ch ronic toxicity data for surrogate organophosphate insecticides – specifically phosphorot hioates – were used to charac terize the chronic toxicity of coumaphos to birds. Phosphorothionate were se lected because they are most likely to have physico/physiochemical properties that are similar to those of coumaphos. Avian chronic, reproductive toxicity data are available for the following phosphorothi onate insecticides: fenitrothion, methyl pa rathion, and parathion ( Table 5-4 ). Of the available data, parathion is the most toxic to birds on a chronic basis. Thus, th e most sensitive chronic avian toxicity endpoint for parathion ( i.e. , NOAEC = 2.85 mg/kg-diet) was used for characterizing the chronic toxicity of coumaphos to birds.

### 52 Table 5-4. Toxicity Data for Surrogate Organophosphorothionate Insecticides

Chemical

PC Code Species NOAEC a (mg/kg-diet) MRID & Classification

Fenitrothion

105901 Bobwhite quail ( Colinus virginianus ) 13 41958401 Acceptable

Mallard duck ( Anas platyrhynchos ) 40 00262755 Acceptable

Methyl parathion

53501 Bobwhite quail ( Colinus virginianus ) 6.3 41179302 Acceptable

Mallard duck ( Anas platyrhynchos ) 14.7 41179301 Supplemental

Parathion

57501 Bobwhite quail ( Colinus virginianus ) 8 41133102 Supplemental

Mallard duck ( Anas platyrhynchos ) 2.85 41133101 Acceptable

a BOLD value used in risk characterization



### 5.2.2 Mammals

Based on a study with rat, coumaphos is highly toxic to mammals on an acute oral basis. In this acute oral study with rats (MRID 00110597), females were the more sensitive sex with an LD 50 

### of 17 mg/kg-bw. Sublethal eff ects were not specified.

In a rat two-year generation reproduction study (MRID 43061701), c holinesterase inhibition was observed at 5 and 25 ppm and was manifested as dose-dependent decreases in erythrocyte (RBC) and plasma cholinesterase (ChE). Relative to concurrent controls , RBC ChE was inhibited 31- 70% at 5 ppm and 53-95% at 25 ppm. Generally, no differences were noted between Day 47 (or 56) and Day 91 ChE levels. Brain levels were significantly inhibited (30%) in F O 

### and F 1 

### females. In pups, plasma and RBC ChE levels were inhi bited (31-44%) at 25 ppm on lactation day 21 but not on lactation day 4. Based on these results , the NOAEL and LOAEL for ChE inhibition were 1 and 5 ppm, respectively. There were no other signs of systemic toxicity. The NOAEL and LOAEL for systemic toxicity were equal to and greater than 25 ppm, respectively. Reproductive toxicity was not observed in th is study. Consequently, the NOAE L for reproductive toxicity was 25 ppm, and the LOAEL for reproductive toxicity was greater than 25 ppm.

5.2.3 Non-Target Terrestrial Invertebrates

Data from guideline studies with honey bees ar e not available. However, three registrantsubmitted studies evaluating the efficacy of coum aphos-impregnated strips to control mites in honey bee hives in Guatemala (MRID 45752811) , Minnesota (MRID 45752812), and Nebraska (MRID 45752810) as well as an abstract of published research describing the control of the small
hive beetles in hives treated with couma phos-impregnated strips (MRID 45752813) have been reviewed and classified as “supplemental” ( Table 5-5 ). In general, coumaphos was efficacious when impregnated strips contained a concentratio n of 5 or 10% active ingredient. It should be noted that in the three varroa mite efficacy studies, fluvalinate (formulated into Apistan strips)
was used following treatment with coumaphos strips and in control groups but had no apparent
effect on mite control.

### 53 In one of the varroa mite studies (MRID 45752812) , bee mortality was quantified and did not appear to be different between control and treated hives ( Table 5-5 ). In the other two varroa mite studies, the study authors stated that no unusual bee mortality was observed following treatment with coumaphos strips without furt her quantification (durat ion: 37-46 days; MRIDs 47572810 and 47572811). Bee mortality was not repor ted in the small hi ve beetle study (duration: 72 hours; MRID 45752812). These studi es were not designed to measure other endpoints related to hive health and long-term effects (followi ng the treatment period). Thus, there is uncertainty regarding the effects of coumaphos on brood, as well as the long-term stability of the hive.

Table 5-5. Summary of Observations of the Ef fect of Coumaphos on Bees Obtained from Efficacy Studies

Study Type Species Summary Source &

Classification Non-guideline: Efficacy of Coumaphos Impregnated Strips
for the Control of Varroa Mite Honey bee ( Apis mellifera ) No unusual bee mortality or injury to the colonies was observed during treatment (37 days) with coumaphos strips. MRID 45752810 Supplemental

Non-guideline: Efficacy of Coumaphos Impregnated Strips
for the Control of Varroa Mite Honey bee ( Apis mellifera ) No unusual adult bee mortality was observed during treatment (46 days) with the coumaphos strips. MRID 45752811 Supplemental

Non-guideline: Efficacy of Coumaphos Impregnated Strips
for the Control of Varroa Mite Honey bee ( Apis mellifera ) No unusual bee mortality or injury to the colonies was observed during treatment (46 days, but only 36 days of bee mortality observations) with coumaphos strips (control group: 329 dead bees, 2.5% group: 348 dead bees, 5% group = 373 dead bees, 10% group: 319 dead bees). However, six colonies died due to starvation (one in control, two in 2.5% coumaphos treatment, two in 5% coumaphos treatment, and one in 10% coumaphos treatment). MRID 45752812 Supplemental

Non-guideline: Efficacy of Coumaphos Impregnated Strips
for the Control of Small Hive
Beetle Honey bee ( Apis mellifera ) No reports were made regarding observations of bee mortality or hive health during treatment (72 hours). MRID 45752813 Supplemental



### Data on the effects of coumaphos on the surviv al, growth, and/or re production of honey bees ( Apis mellifera ) are available from five open literatu re studies as identified via ECOTOX 17 

### ( Table 5-6 ).

Table 5-6. Summary of Observations of the Ef fect of Coumaphos on Bees Obtained from Open Literature Studies as Identified via ECOTOX

Study Type Species Route of Exposure & Toxicity Values ECOTOX No.

& Classification Non-guideline: Effects of coumaphos on queen rearing Honey bee ( Apis mellifera ) Impregnated strips

Not applicable a E066848 Qualitative

17 http://cfpub.epa.gov/ecotox/

### 54 Study Type Species Route of Exposure & Toxicity Values ECOTOX No.

& Classification Non-guideline: Effects of coumaphos on queen rearing Honey bee ( Apis mellifera ) Beeswax in queen cups

10-day NOAEC = 10 mg/kg 10-day LOAEC = 100 mg/kg (based on rejection of transferred larvae and reduced weight of queen pupae) E100380 Quantitative

Non-guideline: Effects of coumaphos on queen rearing Honey bee ( Apis mellifera ) Beeswax in queen cups

10-day NOAEC = 10 mg/kg 10-day LOAEC = 100 mg/kg (based on rejection of transferred larvae and reduced weight of queen pupae) E100910 Quantitative

Non-guideline: Acute and chronic toxicity of coumaphos (as well as effects of coumaphos on hemolymph volume and Nosema infection) in the laboratory Honey bee ( Apis mellifera ) Oral

48-hr LD 50 = 2.99 μg/bee for 8 day old bees
48-hr LD 50 = 3.10 μg/bee for 14 day old bees
48-hr LD 50 = 6.04 μg/bee for 3 day old bees E101175 Quantitative

Non-guideline: Synergistic interactions of coumaphos and tau-fluvalinate in the laboratory Honey bee ( Apis mellifera ) Contact (application to thorax)

24-hr LD 50 = 20.39 μg/bee E119503 Qualitative

a There were only 2 treatment groups, and effects were seen in both groups relative to the control. Therefore, it was not possible to establish NOAECs or concentration-response relationships.



### Three of the studies evaluated the effects of coumaphos on queen rearing. In E066848, honey bee colonies were treated with coumaphos-impre gnated strips and monitored in two separate experiments (see Section 4.3.4 for additional experimental details). There was high mortality in developing queens in colonies treated with ≥ 1 coumaphos strips for more than 24 hours. Physical abnormalities and atypical behavior we re observed in queens due to inclusion of coumaphos strips in colonies. Queen weights and ovary weights we re also significantly lower in treatment groups than the contro l group. Coumaphos concentrati ons increased in the bees and wax after treatments (see Section 4.3.4 for concentrations). This study was classified as “qualitative” for use in the assessment because only two treatment groups were assessed, and effects were seen in both groups relative to the control. Th erefore, it was not possible to
establish NOAECs or concentr ation-response relationships.

In E100910, young honey bee larvae were transferred in to queen cups containing 0 (control), 1, 10, 100, 300, 600, and 1000 mg/kg coumaphos. The c ups with larvae were then placed in queenless colonies and examined after 10 days to determine the rejection rate of transferred larvae and weight of queen pupae. At ≥ 100 mg/kg, there was a signifi cant rejection of larvae compared to control larvae. In addition, there was a significant reduction in the weight of queen pupae at 100 mg/kg compared to the control after 10 days. The 1 and 10 mg/kg treatment groups were not significantly different than the control fo r either endpoint. This study was classified as “quantitative” for use in the assessment.

In E100380, young honey bee larvae were transferred in to queen cups containing 0 (control), 1, 10, 100, and 1000 mg/kg coumaphos. The cups with larvae were then placed in queenless colonies and examined after 10 days to determin e the rejection rate of transferred larvae and weight of queen pupae. The queen cells were then placed in small mating colonies and

### 55 examined after 21 days to determine commerc ial acceptability and mating success based on sperm count. Finally, the queens were introduced to production colonies and monitored for six months. For rejection rate and weight of queen pupae, significant effects were observed in the 100 and 1000 mg/kg coumaphos treatment groups when compared to the control. The 1 and 10 mg/kg treatment groups were not significantly different than the control for either endpoint. Mean sperm count was not significantly differe nt among the control and 1, 10, and 100 mg/kg treatment groups, although there were significant differences between spermatheca color groups. Although not statistic ally significant, the pe rcentage of queens from the 100 mg/kg treatment group surviving for 2-6 months in the production colony was less th an that of queens from the control and 10 mg/kg treatment group. This study wa s classified as “quantit ative” for use in the

assessment.

One study (E119503) evaluated the effects of co umaphos and the pyrethroid tau-fluvalinate administered individually and in combination via contact exposure. Specifically, 3 to 4 day old worker bees were treated with 0 (solvent c ontrol), 0.1, 0.3, 1, 3, and 10 μg/bee via application to the thorax with or without pretreatment with enzyme inhibitors DEM, DEF, or PBO or taufluvalinate. Mortality was record ed 24 hours after treatment. The LD 50 

### of coumaphos in the absence of enzyme inhibitors was 20.39 μg/bee. DEM did not alter the toxicity of coumaphos, but DEF and PBO enhanced the toxicity of coumaphos by 2.8-fold and 4-fold, respectively. When tau-fluvalinate was used as a pretreatme nt, the toxicity of coumaphos increased by 3.4- fold. This study was classified as “qualita tive” for use in the assessment because the experimental design included a solvent control group but did not include a negative control

group.

One study (E101175) examined the toxicity of coumaphos from acute oral and chronic exposures. For the acute toxic ity tests, 3, 8, or 13 day old bees were fed 10 μL of 0.79 M sucrose solution containing 0, 0.8, 1.6, 3.2, 4.8, 6.4, or 8.0 μg coumaphos. Mortality was recorded 16, 24, 32, and 48 hours afte r feeding. For the chronic toxicity test, mixed age bees were fed a 2% coumaphos solution for 7 days, and mortality was recorded. Only a few bees fed coumaphos survived up to 12, 16, and 24 hours in the acute toxicity tests. The LD 50 

### for 3 day old bees was 6.04 μg/bee, whereas the LD 50 

### ’s for 8 and 14 day old bees were 2.99 and 3.10 μg/bee, respectively. During chronic exposure, bees showed 50% mortality at day 7, which corresponded to 3 μg/bee/day. This study was cl assified as “quantitative” for use in the

assessment.

5.2.4 Terrestrial (Upland and Semi-Aquatic) Plants

No data are available for the toxicity of coumaphos to terrestrial plants. Terrestrial plant toxicity data are available for the following organophos phate insecticides: diazinon, disulfoton, fosthiazate, isofenfos, and profenofos (see US EPA, 2010 for discussion of data). Of the available data, profenofos is the most toxic to terrestrial plants. T hus, toxicity data for profenofos ( Table 5-7 ) was used for characterizing the toxi city of coumaphos to terrestrial plants.

Table 5-7. Terrestrial Plant Toxicity Data for Profenofos

Study Type Toxicity Endpoints Source Seedling emergence Most sensitiv e monocot: None MRID 41627307

### 56 Study Type Toxicity Endpoints Source

Tier 2 EC 25 > 1 lb a.i./A
NOAEC = 1 lb a.i./A

Most sensitive dicot: Cucumber ( Cucumis sativus )

EC 25 = 0.13 lb a.i./A
NOAEC = 0.111 lb a.i./A Acceptable

Vegetative vigor
Tier 2 Most sensitive species: None (4 monocots and 6 dicots)

EC 25 : Could not be determined due to lack of concentration response
NOAEC = 1.0 lb a.i./A MRID 41627305 Acceptable



### 5.3 Incident Database Review

Reviews of the Ecological Incident Informa tion System (EIIS, version 2.1.1), which is maintained by the Agency’s Office of Pesticide Programs, and the Avian Monitoring Information System (AIMS), which is maintain ed by the American Bird Conservatory, on May 31, 2013 yielded incidents involvi ng terrestrial animals.

Two of the incidents involved birds:

 In a letter dated January 7, 1983, the U.S. Fish and Wildlif e Service (USFWS) reported an unknown number of American wigeon(s) ( Anas americana ) was found dead in November 1981 in Washington state near a pond adjacent to a feedlot (EIIS B0000-400- 27 and AIMS). The cause of death was attri buted to coumaphos. However, information on the exposure pathway was not provided.

 The Canadian Wildlife Service and USFWS reported that one bald eagle ( Haliaeetus leucocephalus ) was observed dead or dying in Na trona County, Wyoming on March 2, 1986 (AIMS). Investigators were certain th at coumaphos was responsible for this incident based on detection of coumaphos in gut contents and qua ntification of brain cholinesterase activity.

The remaining incidents involved honey bees:

 Eight kills of honey bees ( Apis mellifera ) from September 2001 to September 2002 were reported by the Minnesota Department of Agriculture (EIIS I014202-02, I014202-03, I014202-04, I014202-05, I014202-07, I014202-08, I014202-09, I014202-17). In all of these incidents, residue analyses detected coumaphos in bee tissue and/or pollen. No other pesticides were detecte d. Investigators concluded th at insufficient evidence was available to determine if the exposure to coum aphos played a role in these bee kills or was merely incidental.

 In June 2009, after the aerial application of the active i ngredients carbaryl, potassa, fenoxaprop-ethyl to crop fiel ds in Box Elder County, UT, 30% of the bee hives ( Apis mellifera ) died within a month (EIIS I021587-001) . Subsequently, there were 3 more applications at bloom with Wa rrior (active ingredient: 22.8% lambda -cyhalothrin) through August. By December of 2009, 320 hi ves collapsed. Lab testing detected 14 different active ingredients including c oumaphos in bee tissue and/or bee wax.

In addition to the incidents reco rded in EIIS and AIMS, additiona l incidents are reported to the Agency in aggregated form. Pesticide registrant s report certain types of incidents to the Agency as aggregate counts of incidents occurring per product pe r quarter. Ecologi cal incidents reported

### 57 in aggregate reports include those categorized as ‘minor fish and wildlife’ (W-B), ‘minor plant’ (P-B), and ‘other non-target’ (ONT) incidents. ‘Other non-target’ incide nts include reports of
adverse effects to insects and ot her terrestrial invertebrates. For coumaphos, registrants have reported no minor fish and wildlife incidents, no minor plant incidents, and one other non-target incident as of June 4, 2013. The minor other non-t arget incident involved the use of Checkmite (bee strip).

The total number of actual incide nts associated with the use of coumaphos may be higher than what is reported to the Agency. Incident s may go unreported since effects may not be immediately apparent and/or readily attributed to th e use of a chemical.

### 58 

## 6 Risk Characterization

6.1 Risk Estimation

Estimates of exposure and toxicity of coumaphos are integrated using st andard risk quotient (RQ) methods to evaluate the potential for adverse ecological effects to mammalian, avian, aquatic, and other non-target spec ies. RQ results for non-target terrestrial and aquatic animals and plants are described in this section and re present expected direct effects to organisms ( i.e

., effects from direct toxicity to coumaphos exposure) in contrast to indirect effects to organisms resulting from a modification of a resource such as loss of thei r prey or habitat.

6.1.1 Direct Effects to Aquatic Organisms

Risk to aquatic organisms from exposure via runoff (CAFO manur e applied to land, nonregulated small CAFO, rangeland) was estimated using EECs from PRZM/EXAMS modeling.

Risk to aquatic organisms from exposure via wash -off from the skin of treated livestock that
enter bodies of water was estimated in two ways. First, RQs for wash-off from one cow entering a 1 acre, 6 foot deep body of water were calculated using EECs in Tables 4-8 and 4-10 ( i.e.

, EEC/cow) and the following formula:

RQ/cow = (EEC/cow in μg/L) / (Toxicity endpoint in μg/L)

Second, the number of cows entering a 1 acre, 6 foot deep body of water that would cause an LOC exceedance was calculated using the following formula:

Number of cows to cause LOC exceedance = LOC / (RQ/cow)

6.1.1.1 Fish and Aquatic-Phase Amphibians

Freshwater fish acute RQs were calculated using the most sensitive acute toxicity endpoint of 340 μg/L (bluegill sunfish; MRID 40098001); freshwat er fish chronic RQs were calculated using an estimated chronic toxicity endpoint (for bluegill sunfish) of 4.4 μg/L ( Tables 6-1 and 6-2 ).

Freshwater fish acute and chronic RQs for r unoff range are <0.01 and <0.01 to 0.05 respectively.
There are no freshwater fish acute or chronic LOC exceedances for runoff.

Freshwater fish acute and chronic RQs for wash-o ff from one cow entering a 1 acre, 6 foot deep body of water are <0.01. Hundreds of cows would need to enter a 1 acre, 6 foot deep body of
water to cause an acute or chronic LOC exceedance for freshwater fish.

### 59 Table 6-1. Freshwater Fish Risk Quotients (RQs) for Runoff

PRZM/EXAMS

Scenarios Sources of a.i. from Application Scenario Wash-Off

Fraction Acute RQ Chronic RQ

Texas: Spray Application (42% flowable concentrate) BSSTurf Runoff from CAFO manure applied to land (No incorporation of manure into soil) 0.02 <0.01 0.01

Runoff from non-regulated small CAFO 0.02 <0.01 0.04 RangeBSS Runoff from rangeland 0.02 <0.01 <0.01 Rest of U.S.: Back Rubber Applicatio n (11.6% emulsifiable concentration) PA Turf Runoff from CAFO manure applied to land (No incorporation of manure into soil) 0.027 <0.01 0.01

Runoff from non-regulated small CAFO 0.027 <0.01 0.05 Runoff from rangeland 0.027 <0.01 <0.01



### 6-2. Freshwater Fish Risk Quotients (RQs) for Wash-Off from Treated Livestock That

Enter Bodies of Water

Maximum Application Rate Wash-Off

Fraction Acute RQ/cow Number of Cows to

Cause Acute LOC

Exceedance Chronic RQ/cow Number of Cows to

Cause Chronic

LOC Exceedance Type (lb a.i./ animal) (mg a.i./

ft 2 cow hide) Listed NonListed Listed & NonListed

Texas: Dip Vat Application (42% flowable concentrate) Single 0.027 272 0.02 <0.01 1308 13077 <0.01 550 Rest of U.S.: Back Rubber Applicatio n (11.6% emulsifiable concentration) Single 0.01 101 0.027 <0.01 2429 24286 <0.01 1100



### Estuarine/marine fish acute RQs were calculated using the most sensitive acute toxicity endpoint of 280 μg/L (sheepshead minnow; MRID 40228401); es tuarine/marine fish chronic RQs were calculated using an estimated chronic toxicity endpoint (for sheepshead minnow) of 3.6 μg/L ( Table 6-3 and 6-4 ).

Estuarine/marine fish acute a nd chronic RQs for runoff are <0.01 and <0.01 to 0.06, respectively.
There are no estuarine/marine fish acute or chronic LOC exceedances for runoff.

Estuarine/marine fish acute and chronic RQs for wash-off from one cow entering a 1 acre, 6 foot deep body of water are <0.01. Hundreds of cows w ould need to enter a 1 acre, 6 foot deep body
of water to cause an acute or chronic LOC exceedance for estuarine/marine fish.

Table 6-3. Estuarine/Marine Fish Risk Quotients (RQs) for Runoff

PRZM/EXAMS

Scenarios Sources of a.i. from Application Scenario Wash-Off

Fraction Acute RQ Chronic RQ

Texas: Spray Application (42% flowable concentrate) BSSTurf Runoff from CAFO manure applied to land (No incorporation of manure into soil) 0.02 <0.01 0.01

Runoff from non-regulated small CAFO 0.02 <0.01 0.05 RangeBSS Runoff from rangeland 0.02 <0.01 <0.01 Rest of U.S.: Back Rubber Applicatio n (11.6% emulsifiable concentration) PA Turf Runoff from CAFO manure applied to land (No incorporation of manure into soil) 0.027 <0.01 0.01

Runoff from non-regulated small CAFO 0.027 <0.01 0.06

### 60 PRZM/EXAMS

Scenarios Sources of a.i. from Application Scenario Wash-Off

Fraction Acute RQ Chronic RQ

Runoff from rangeland 0.027 <0.01 <0.01



### Table 6-4. Estuarine/Marine Fish Risk Qu otients (RQs) for Wash-Off from Treated

Livestock That Enter Bodies of Water a

Maximum Application Rate Wash-Off

Fraction Acute RQ/cow Number of Cows to

Cause Acute LOC

Exceedance Chronic RQ/cow Number of Cows

to Cause Chronic

LOC Exceedance Type (lb a.i./ animal) (mg a.i./

ft 2 cow hide) Listed NonListed Listed & NonListed

Texas: Dip Vat Application (42% flowable concentrate) Single 0.027 272 0.02 <0.01 1077 10769 <0.01 450 Rest of U.S.: Back Rubber Applicatio n (11.6% emulsifiable concentration) Single 0.01 101 0.027 <0.01 2000 20000 <0.01 900

a 1 acre, 6 foot deep body of water



### 6.1.1.2 Aquatic Invertebrates

Freshwater invertebrate acute RQs were calcul ated using the most sensitive acute toxicity endpoint of 0.074 μg/L ( G. lacustris ; MRIDs 05009242 and 40098001); freshwater invertebrate chronic RQs were calculated using an es timated chronic toxi city endpoint (for G. lacustris ) of 0.0127 μg/L ( Table 6-5 and 6-6 ).

Freshwater invertebrate acute and chronic RQs for runoff range from 0.02 to 3.4 and 0.09 to 17, respectively. There are multiple acute and chro nic exceedances across runoff exposure pathways
for both Texas and the rest of the U.S.

Freshwater invertebrate acute RQs for wash-off from one cow entering a 1 acre, 6 foot deep body of water are 0.11 and 0.05 for Texas and the rest of the U.S., respect ively, whereas chronic RQs for wash-off from one cow entering a 1 acre, 6 foot deep body of water are 0.63 to 0.31 for Texas and the rest of the U.S., re spectively. Only one and five to ten cows would need to enter a 1 acre, 6 foot deep body of water to cause acute LOC exceedances for listed and non-listed freshwater invertebrates, respec tively. Only two and four cows would need to enter the same body of water to cause a chronic LOC exceedance fo r freshwater invertebrates in Texas and the rest of the U.S., respectively.

Table 6-5. Freshwater Invertebrate Risk Quotients (RQs) for Runoff

PRZM/EXAMS

Scenarios Sources of a.i. from Application Scenario Wash-Off

Fraction Acute RQ Chronic RQ

Texas: Spray Application (42% flowable co ncentrate; 3 applications @ 0.021 lb/AU) BSSTurf Runoff from CAFO manure applied to land No incorporation of manure into soil

0.02 0.68** 2.4*** Incorporation of manure into soil within a day

0.02 0.04 0.17 Runoff from non-regulated small CAFO 0.02 3.4** 17*** RangeBSS Runoff from rangeland 0.02 0.07* 0.31 Rest of U.S.: Back Rubber Applicat ion (11.6% emulsifiable concentration; 6 applications @ 0.00829 lb/AU) PA Turf Runoff from CAFO manure applied to land No incorporation of manure into soil

### 61 PRZM/EXAMS

Scenarios Sources of a.i. from Application Scenario Wash-Off

Fraction Acute RQ Chronic RQ

0.027 0.54** 2.4*** Incorporation of manure into soil within a day

0.027 0.03 0.14 Runoff from non-regulated small CAFO 0.027 3.9** 18*** Runoff from rangeland 0.027 0.02 0.09 *exceeds aquatic animal acute listed species LOC (=0.05) **exceeds aquatic animal acute non-listed species LOC (=0.5) *** exceeds aquatic animal chronic listed and non-listed species LOC (=1)



### Table 6-6. Freshwater Invertebrate Risk Qu otients (RQs) for Wash-Off from Treated

Livestock That Enter Bodies of Water a

Maximum Application Rate Wash-Off

Fraction Acute RQ/cow Number of Cows to

Cause Acute

LOC Exceedance Chronic RQ/cow Number of Cows to

Cause Chronic

LOC Exceedance Type (lb a.i./ animal) (mg a.i./

ft 2 cow hide) Listed NonListed Listed &

Non-Listed

Texas: Dip Vat Application (42% flowable concentrate) Single 0.027 272 0.02 0.11 <1 5 0.63 2 Rest of U.S.: Back Rubber Applicatio n (11.6% emulsifiable concentration) Single 0.01 101 0.027 0.05 <1 10 0.31 4

a 1 acre, 6 foot deep body of water



### Estuarine/marine invertebrate acute RQs were cal culated using the most sensitive acute toxicity endpoint of 2.0 μg/L (pink shrimp; MRID 40228401); estuarine/marine inve rtebrate chronic RQs were calculated using the estimated chronic t oxicity endpoint (for pink shrimp) of 0.3421 μg/L ( Table 6-7 and 6-8 ).

Estuarine/marine invertebrate acute and chr onic RQs for runoff range from <0.01 to 0.15 and <0.01 to 0.67, respectively. The only LOC exceedances are for acute exposure via runoff from non-regulated small CAFO for listed species of estuarine/marine invertebrates.

Estuarine/marine invertebrate acute RQs for wa sh-off from one cow entering a 1 acre, 6 foot deep body of water are <0.01 for Texas and the restof the U.S. whereas chronic RQs for washoff from one cow entering a 1 acre, 6 foot d eep body of water are 0.02 to 0.01 for Texas and the rest of the U.S., respectively. Only 13 to 25 cows would need to enter a 1 acre, 6 foot deep body
of water to cause acute LOC exceedances for liste d estuarine/marine invertebrates whereas over a hundred cows would need to enter a 1 acre, 6 foot deep body of water to cause acute LOC
exceedances for non-listed freshwater invertebrate s. At least 43 and 86 cows would need to enter the same body of water to cause a chronic LOC exceedance for estuarine/marine
invertebrates in Texas and the rest of the U.S., respectively.

### 62 Table 6-7. Estuarine/Marine Invertebra te Risk Quotients (RQs) for Runoff

PRZM/EXAMS

Scenarios Sources of a.i. from Application Scenario Wash-Off

Fraction Acute RQ Chronic RQ

Texas: Spray Application (42% flowable concentrate) BSSTurf Runoff from CAFO manure applied to land No incorporation of manure into soil

0.02 0.03 0.09 Incorporation of manure into soil within a day

0.02 <0.01 0.01 Runoff from non-regulated small CAFO 0.02 0.13* 0.61 RangeBSS Runoff from rangeland 0.02 <0.01 0.01 Rest of U.S.: Back Rubber Applicatio n (11.6% emulsifiable concentration) PA Turf Runoff from CAFO manure applied to land No incorporation of manure into soil

0.027 0.02 0.09 Incorporation of manure into soil within a day

0.027 <0.01 0.01 Runoff from non-regulated small CAFO 0.027 0.15* 0.67 Runoff from rangeland 0.027 <0.01 <0.01 *exceeds aquatic animal acute listed species LOC (=0.05)



### 6-8. Estuarine/Marine Invertebrate Risk Quotients (RQs) for Wash-Off from Treated

Livestock That Enter Bodies of Water

Maximum Application Rate Wash-Off

Fraction Acute RQ/cow Number of Cows to

Cause Acute LOC

Exceedance Chronic RQ/cow Number of Cows

to Cause Chronic

LOC Exceedance Type (lb a.i./ animal) (mg a.i./

ft 2 cow hide) Listed NonListed Listed &

Non-Listed

Texas: Dip Vat Application (42% flowable concentrate) Single 0.027 272 0.02 <0.01 13 125 0.02 43 Rest of U.S.: Back Rubber Applicatio n (11.6% emulsifiable concentration) Single 0.01 101 0.027 <0.01 25 250 0.01 86

a 1 acre, 6 foot deep body of water



### Since no data are available for the toxicity of coumaphos to benthic (sediment-dwelling) invertebrates, acute and chronic RQs for benthic invertebrates ( Tables 6-9 and 6-10 ) were calculated using the most sensitive water colu mn acute and chronic toxicity endpoints for coumaphos ( i.e. , 0.074 and 0.0127 μg/L, respectively).

Benthic invertebrate acute and chronic RQs for runoff range from 2.3 to 2.6 and 13 to 15, respectively. All benthic invertebrate RQs fo r runoff from a non-regulated small CAFO exceed

LOCs.

Benthic invertebrate acute RQs for wash-off from one cow entering a 1 acre, 6 foot deep body of water range from 0.04 to 0.07 whereas chronic RQs for wash-off from one cow entering a 1 acre, 6 foot deep body of water range from 0.24 to 0.55. Less than 13 cows would need to enter a 1 acre, 6 foot deep body of water to cause acute and chronic LOC exceedances for listed and nonlisted benthic invertebrates.

### 63 Table 6-9. Benthic Invertebrate Risk Quotients (RQs) for Runoff

PRZM/EXAMS

Scenarios Sources of a.i. from Application Scenario Wash-Off Fraction Acute RQ Chronic RQ

Texas: Spray Application (42% flowable co ncentrate; 3 applications @ 0.021 lb/AU) BSSTurf Runoff from non-regulated small CAFO 0.02 2.3** 13*** Rest of U.S.: Back Rubber Applicat ion (11.6% emulsifiable concentration; 6 applications @ 0.00829 lb/AU) PA Turf Runoff from non-regulated small CAFO 0.03 2.6** 15*** **exceeds aquatic animal acute non-listed species LOC (=0.5) *** exceeds aquatic animal chronic listed and non-listed species LOC (=1)



### 6-10. Benthic Invertebrate Risk Quotients (RQs) for Wash-Off from Treated Livestock

That Enter Bodies of Water

Maximum Application Rate Wash-Off

Fraction Acute RQ/cow Number of Cows to

Cause Acute LOC

Exceedance Chronic RQ/cow Number of Cows

to Cause Chronic

LOC Exceedance Type (lb a.i./ animal) (mg a.i./

ft 2 cow hide) Listed NonListed Listed &

Non-Listed

Texas: Dip Vat Application (42% flowable concentrate) Single 0.027 272 0.02 0.07 <1 8 0.55 2 Rest of U.S.: Back Rubber Applicatio n (11.6% emulsifiable concentration) Single 0.01 101 0.027 0.04 <1 13 0.24 5

a 1 acre, 6 foot deep body of water



### 6.1.1.3 Aquatic Plants

RQs for aquatic non-vascular plants for exposur e via runoff and wash-off were not calculated because of the lack of toxicity data specific to coumaphos. Risk to aquatic non-vascular plants from these exposure pathways is discussed in th e Risk Description sect ion of this document.

RQs for listed aquatic vascular plants ( Tables 6-11 and 6-12 ) were calculated with the toxicity endpoint of 166 μg/L ( L. gibba ; MRID 43822801). RQs for non-liste d aquatic vascular plants
were not calculated because the EC 50 

### endpoint is non-definitive ( i.e. , >166 μg/L).

Aquatic vascular plant RQs for runoff are all <0.01. Therefore, the listed aquatic plant LOC of 1 is not exceeded for any runoff exposure pathways.

Aquatic vascular plant RQs for wash-off from one cow entering a 1 acre, 6 foot deep body of water range are all <0.01. Thousands of cows wo uld need to enter a 1 acre, 6 foot deep body of
water to cause an LOC exceedance from wash-off for listed aquatic vascular plants.

Table 6-11. Aquatic Vascular Plant Risk Quotients (RQs) for Runoff

PRZM/EXAMS

Scenarios Sources of a.i. from Application Scenario Wash-Off

Fraction RQs

Listed Non-Listed Texas: Spray Application (42% flowable concentrate) BSSTurf Runoff from CAFO manure applied to land (No incorporation of manure into soil) 0.02 <0.01

Not calculated Runoff from non-regulated small CAFO 0.02 <0.01 RangeBSS Runoff from rangeland 0.02 <0.01 Rest of U.S.: Back Rubber Applicatio n (11.6% emulsifiable concentration)

### 64 PRZM/EXAMS

Scenarios Sources of a.i. from Application Scenario Wash-Off

Fraction RQs

Listed Non-Listed PA Turf Runoff from CAFO manure applied to land (No incorporation of manure into soil) 0.027 <0.01

Not calculated Runoff from non-regulated small CAFO 0.027 <0.01 Runoff from rangeland 0.027 <0.01



### Table 6-12. Aquatic Vascular Plants Risk Quotients (RQs) for Was h-Off from Treated

Livestock That Enter Bodies of Water a

Maximum Application Rate Wash-Off

Fraction RQ/cow Number of Cows to Cause

LOC Exceedance Type (lb a.i./ animal) (mg a.i./

ft 2 cow hide) Listed Non-Listed Listed Non-Listed

Texas: Dip Vat Application (42% flowable concentrate) Single 0.027 272 0.02 <0.01 Not calculated 20750 Not calculated Rest of U.S.: Back Rubber Applicatio n (11.6% emulsifiable concentration) Single 0.01 101 0.027 <0.01 Not calculated 41500 Not calculated

a 1 acre, 6 foot deep body of water



### 6.1.2 Direct Effects to Terrestrial Organisms

6.1.2.1 Birds, Reptiles, and Terrestrial-Phase Amphibians

Avian acute RQs were calculated for three exposur e pathways resulting from the application of coumaphos to livestock:

 contact with/ingestion of hair and skin debris from treated cattle and/or contaminated soil
and feed in and around treatment areas usi ng dose-based EECs for treated cow hides ( i.e.

, 272 and 101 mg a.i./ft 2 

### cow hide for Texas and the rest of the U.S., respectively) and dietary-based EECs of 3 70-1228 mg a.i./kg-diet;

 ingestion of coumaphos-contaminated bird ca rcasses using dose- and dietary-based EECs for coumaphos intake via secondary ingestion ( i.e. , 1.17 x 10 -6 

### -3.87 x 10 -5 

### mg a.i./gbw/day and 0.039-0.129 mg/g-diet, respectively);

 ingestion of food items on land receiving ma nure from CAFOs using EECs from T-REX;
and

 ingestion of contaminated fish.

To calculate acute dose-based RQs for the former (primary) exposure pathway, the most
sensitive avian acute oral toxicity endpoint ( i.e. , LD 50 

### = 2.4 mg/kg-bw for bobwhite quail; MRID 00112843) was adjusted for the weight of the black-billed magpie ( i.e. , 186 g; Dunning, 1984), the species most likely to be exposed to c oumaphos according to the pilot field study (MRID 42512604), according to the formula provided in Table 6-13 and compared to the dose-based EECs of 272 and 101 mg a.i./ft 2 

### cow hide for Texas and the rest of the U.S., respectively. Avian acute dose-based RQs for exposure via contact wi th/ingestion of hair and skin debris from
treated cattle and/or contamin ated soil feed in and around tr eatment areas are 609 and 226 for
Texas and the rest of the U.S., respectively ( Table 6-14 ). These acute dose-based RQs exceed
the avian acute listed an d non-listed species LOCs of 0.1 and 0.5, respectively.

### 65 Table 6-13. Formula for Calculation of Weight-Adjusted Coumaphos LD 50 

### for the BlackBilled Magpie

Adjusted LD 50(black-billed magpie) (mg/kg-bw) = Avian LD 50 (mg/kg-bw) ቀ SW(g)

TW(g) ቁ ሺ x-1 ሻ ൌ 	 2.4 ൬ 186

178 ൰ ሺ ଵ.ଵହିଵ ሻ

= 2.4 mg/kg-bw

Where:
Avian LD 50 = most sensitive avian acute oral toxicity endpoint (2.4 mg/kg-bw)

SW = body weight of the assessed avian species (186 g black-billed magpie) TW = body weight of tested avian species (178 g bobwhite quail) x = Mineau scaling factor for birds (EFED default 1.15)



### Table 6-14. Avian Acute Dose-B ased Risk Quotient (RQ) a 

### for Exposure via Contact with/Ingestion of Hair and Skin Debris from Treated Cattle and/or Contaminated Soil and Feed In and Around Treatment Areas Using EECs for Treated Cow Hides b

Dose-Based EEC (mg a.i./ft 2 cow hide) Adjusted LD 50(black-billed magpie) (mg/kg-bw) Black-Billed Magpie (kg) Dose-Based RQ a

Texas: Dip Vat Application (42% flowable concentrate)

272 b 2.4 0.186 609** Rest of U.S.: Back Rubber Applicatio n (11.6% emulsifiable concentration)

101b 2.4 0.186 226** ** exceeds acute listed and non-listed LOCs (=0.5 and 0.1, respectively)

a 

### RQൌ EEC	ሺmg/ft 2 cow	hideሻ

adjusted	LD 50 ሺ mg/kg‐bw ሻ *	black‐billed	magpie	ሺkgሻ



### To calculate an acute dietary-based RQ for primary exposure of birds to coumaphos, the most
sensitive avian subacute di etary toxicity endpoint ( i.e. , LC 50 

### = 82.1 mg/kg-bw for bobwhite quail; MRID 00112843) was compared to the di etary-based EECs of 370, 853, and 1228 mg/kgdiet to yield avian acute di etary-based RQs of 4.5, 10, and 15, respectively (= [370, 853, or 1228]/82.1). These dietary-based acute RQs for e xposure via contact with/i ngestion of hair and
skin debris from treated cattle and/or contam inated soil/feed in and around treatment areas
exceed the avian acute listed and non-listed species LOCs of 0.1 and 0.5, respectively.

To calculate an acute dose-based RQ for sec ondary exposure of birds to coumaphos, the most
sensitive avian acute oral toxicity endpoint ( i.e. , LD 50 

### = 2.4 mg/kg-bw for bobwhite quail; MRID 00112843) was adjusted for the weight of the red-tailed hawk ( i.e. , 1100 g; USEPA, 1993b), a representative avian predator, acco rding to the formula provided in Table 6-15 and compared to
the dose-based EECs of 1.17 x 10 -5 

### , 2.67 x 10 -5 

### , or 3.87 x 10 -5 

### mg a.i./g-bw/day. Avian acute dose-based RQs for exposure via ingestion of coumaphos-contaminated bird carcasses are 0.012, <0.01, and <0.01 (= [1.17 x 10 -5 

### , 2.67 x 10 -5 

### , or 3.87 x 10 -5 

### ]/0.0032). These acute dose-based RQs do not exceed the avian acute listed a nd non-listed species LOCs of 0.1 and 0.5, respectively.

### 66 Table 6-15. Formula for Calculation of Weight-Adjusted Coumaphos LD 50 

### for the RedTailed Hawk

Adjusted LD 50(red-tailed hawk) (mg/kg-bw) = Avian LD 50 (mg/kg-bw) ቀ SW(g)

TW(g) ቁ ሺ x-1 ሻ ൌ 	 2.4 ൬ 1100

178 ൰ ሺ ଵ.ଵହିଵ ሻ

= 3.2 mg/kg-bw = 0.0032 mg/g-bw

Where:
Avian LD 50 = most sensitive avian acute oral toxicity endpoint (2.4 mg/kg-bw) SW = body weight of the assessed avian species (1100 g red-tailed hawk) TW = body weight of tested avian species (178 g bobwhite quail) x = Mineau scaling factor for birds (EFED default 1.15)



### To calculate an acute dietary-based RQ for sec ondary exposure of birds to coumaphos, the most
sensitive avian subacute di etary toxicity endpoint ( i.e. , LC 50 

### = 82.1 mg/kg-bw for bobwhite quail; MRID 00112843) was compared to dietary-ba sed EECs of 39, 89, and 129 mg/kg-diet to yield avian acute dietary-based RQs of 0.48, 0.11, and 1.5 (= [39, 89, or 129]/82.1). The latter dietary-based acute RQ for exposure via inges tion of coumaphos-contaminated bird carcasses
exceeds the avian acute listed and non-listed species LOCs of 0.1 a nd 0.5, respectively; the former RQs exceed the li sted species LOC of 0.1.

T-REX was used to calculate avian acute RQs for ingestion of food items on land receiving manure from CAFOs ( Table 6-16 ). Avian acute RQs range from 0.02 to 4.52. The avian acute non-listed and listed species LOCs of 0.5 and/or 0.1, respectively, are exceeded for small and
medium birds.

Table 6-16. Avian Risk Quotients (RQs) for Application of CAFO Manure to Land

Source of Exposure RQs

Small (20 g) Medium (100 g) Large (1000 g) Texas: Spray Application (42% flowable concentrate)

CAFO manure applied to land No incorporation into soil 4.52** 0.71** 0.05 Incorporation into soil within a day 2.71** 0.43* 0.03 Rest of U.S.: Back Rubber Applicatio n (11.6% emulsifiable concentration)

CAFO manure applied to land No incorporation into soil 2.77** 0.44* 0.03 Incorporation into soil within a day 1.54** 0.24* 0.02 * exceeds avian acute listed species LOC (=0.1) **exceeds avian acute non-listed species LOC (=0.5)



### KABAM was used to calculate acute dose- and di etary-based RQs for ingestion of contaminated fish ( Table 6-17 ) using a Km of 0.936/d for fish that was derived from raw data for the fish BCF study. The LOC of 0.1 for listed sp ecies of sandpipers and rails is exceeded for wash-off from
the skin of 100 cows that enter a body.

### 67 Table 6-17. Avian Risk Quotients (RQs) for Birds Consuming Fish Contaminated by Coumaphos

Source of Fish Exposure PRZM/EXAMS

Scenario Wash-Off

Fraction Wildlife Species Acute RQs

Dose-Based DietaryBased Texas: Spray Application (42% flowable concentrate)

Runoff from non-regulated
small CAFO BSSTurf 0.02 Sandpipers 0.084 0.002

Cranes 0.004 0.002

Rails 0.041 0.002

Herons 0.005 0.002 Small osprey 0.004 0.001 White pelican 0.001 0.000

Wash-off from
the skin of 100
cows that enter a body of water NA 0.02 Sandpipers 0.268* 0.005

Cranes 0.013 0.005

Rails 0.132* 0.006

Herons 0.018 0.005 Small osprey 0.014 0.003 White pelican 0.003 0.001 Rest of U.S.: Back Rubber Applicatio n (11.6% emulsifiable concentration)

Runoff from non-regulated
small CAFO PA Turf 0.027 Sandpipers 0.097 0.002

Cranes 0.005 0.002

Rails 0.048 0.002

Herons 0.006 0.002 Small osprey 0.005 0.001 White pelican 0.001 0.001

Wash-off from
the skin of 100
cows that enter a body of water NA 0.027 Sandpipers 0.135** 0.003

Cranes 0.007 0.002

Rails 0.066 0.003

Herons 0.009 0.002 Small osprey 0.007 0.001 White pelican 0.001 0.001 * exceeds avian acute listed species LOC (=0.1)



### Avian chronic RQs were not calculated for any expos ure pathways because of the lack of chronic toxicity data specific for coumaphos. Risk to birds from chronic exposure is discussed in the Risk Description section of this document.

6.1.2.2 Mammals

Mammalian RQs were calculated for two exposure pathways resulting from the application of coumaphos to livestock: ingestion of coumaphos -contaminated bird carcasses using dose- and dietary-based EECs for coumaphos in take via secondary ingestion ( i.e. , 4.16 x 10 -6 

### -1.38 x 10 -5 

### mg a.i./g-bw/day and 0.039-0.129 mg/g-diet, resp ectively) and ingesti on of food items on land receiving manure from CAFOs using EECs in terms of LD 50 

### /ft 2 

### from T-REX.

Acute dietary-based RQs for mammals were not cal culated due to the lack of an acute dietarybased toxicity endpoint.

To calculate an acute dose-based RQ for sec ondary exposure of mammals to coumaphos, the most sensitive mammalian acute oral toxicity endpoint ( i.e. , LD 50 

### = 17 mg/kg-bw for rat; MRID 00110597) was adjusted for the weight of the red fox ( i.e. , 4500 g; USEPA, 1993b), a

### 68 representative mammalian predator, acco rding to the formula provided in Table 6-18 and compared to dose-based EECs of 4.16 x 10 -6 

### , 9.49 x 10 -6 

### , and 1.38 x 10 -5 

### mg a.i./g-bw/day. Mammalian acute dose-based RQs for exposure via ingestion of coumapho s-contaminated bird carcasses are <0.01 (= [4.16 x 10 -6 

### , 9.49 x 10 -6 

### , or 1.38 x 10 -5 

### ]/0.025). These acute dose-based RQs do not exceed the mammalian acute listed and non-listed species LOCs of 0.1 and 0.5, respectively.

Table 6-18. Formula for Calculation of Weight-Adjusted Coumaphos LD 50 

### and NOAEL

for the Red Fox

Adjusted LD 50(red fox) (mg/kg-bw) = Mammalian LD 50 (mg/kg-bw) ቀ SW(g)

TW(g) ቁ ሺ 0.25 ሻ ൌ 	 17 ൬ 4500

350 ൰ ሺ ଴.ଶହ ሻ

= 25 mg/kg-bw = 0.025 mg/g-bw

Adjusted NOAEL (red fox) (mg/kg-bw) = Mammalian NOAEL (mg/kg-bw) ቀ SW(g)

TW(g) ቁ ሺ 0.25 ሻ ൌ 	 1.79 ൬ 4500

350 ൰ ሺ ଴.ଶହ ሻ

= 2.63 mg/kg-bw = 0.00263 mg/g-bw

Where:
Mammalian LD 50 or NOAEL = most sensitive mammalian acute oral or chronic toxicity endpoint (17 or 1.79 mg/kg-bw, respectively) SW = body weight of the assessed avian species (4500 g red fox) TW = body weight of tested mammalian species (350 g rat)



### To calculate a chronic dose-based RQ for secondary exposure of mammals to coumaphos, the most sensitive mammalian chronic toxicity endpoint ( i.e. , NOAEL = 1.79 mg/kg-bw for rat; MRID 43061701) was adjusted for th e weight of the red fox ( i.e. , 4500 g; USEPA, 1993b), a representative mammalian predator, acco rding to the formula provided in Table 6-18 and compared to dose-based EECs of 4.16 x 10 -6 

### , 9.49 x 10 -6 

### , and 1.38 x 10 -5 

### mg a.i./g-bw/day. Mammalian chronic dose-based RQs for exposure vi a ingestion of coumap hos-contaminated bird carcasses are <0.01 (= [4.16 x 10 -6 

### , 9.49 x 10 -6 

### , or 1.38 x 10 -5 

### ]/0.00263). These chronic dosebased RQs do not exceed the mammalian chroni c listed and non-listed species LOC of 1.

To calculate a chronic dietary-based RQ for s econdary exposure of mammals to coumaphos, the most sensitive mammalian chronic toxicity endpoint ( i.e. , NOAEC = 25 mg/kg-diet for rat; MRID 43061701) was compared to dietary-based EECs of 39, 89, and 129 mg/kg-diet to yield mammalian chronic dietary-based RQs of 1.5, 3.5, and 5.2 (= [39, 89, or 129]/25). These dietary-based chronic RQs for exposure via inge stion of coumaphos-contam inated bird carcasses
exceed the mammalian chronic listed and non-listed species LOC of 1.

T-REX was used to calculate mammalian RQs fo r ingestion of food items on land receiving manure from CAFOs ( Table 6-19 ). Mammalian acute RQs range from <0.01 to 0.28. The mammalian acute listed species LOC of 0.1 is exceeded for small and medium mammals.

### 69 Table 6-19. Mammalian Risk Quotients (RQs) for Application of CAFO Manure to Land

Source of Exposure RQs

Small (15 g) Medium (35 g) Large (1000 g) Texas: Spray Application (42% flowable concentrate)

CAFO manure applied to land No incorporation into soil 0.28* 0.15* 0.01 Incorporation into soil within a day 0.17* 0.09 0.01 Rest of U.S.: Back Rubber Applicatio n (11.6% emulsifiable concentration)

CAFO manure applied to land No incorporation into soil 0.17* 0.09 0.01 Incorporation into soil within a day 0.09 0.05 <0.01 * exceeds mammalian acute listed species LOC (=0.1)



### KABAM was used to calculate dose- and dietary- based RQs for ingestion of contaminated fish ( Table 6-20 ) using a Km of 0.936/d for fish that was derived from raw data for the fish BCF study. There are no exceedances for ma mmals ingesting contaminated fish.

Table 6-20. Mammalian Risk Quotients (RQs) for Mammals Consuming Fish Contaminated by Coumaphos

Source of

Fish Exposure PRZM/

EXAMS

Scenario Wash-Off

Fraction Wildlife Species Acute DoseBased RQs Chronic RQs

DoseBased DietaryBased Texas: Spray Application (42% flowable concentrate)

Runoff from

nonregulated
small CAFO BSSTurf 0.38 Fog/water shrew 0.003 0.041 0.007

Rice rat/star-nosed mole 0.003 0.038 0.006

Small mink 0.001 0.017 0.003 Large mink 0.001 0.019 0.003

Small river otter 0.002 0.020 0.003 Large river otter 0.001 0.012 0.001

Wash-off
from the skin
of 100 cows
that enter a body of

water NA 0.38 Fog/water shrew 0.010 0.132 0.024

Rice rat/star-nosed mole 0.009 0.122 0.018

Small mink 0.004 0.055 0.009 Large mink 0.004 0.061 0.009

Small river otter 0.005 0.065 0.009 Large river otter 0.003 0.037 0.005 Rest of U.S.: Back Rubber Applicatio n (11.6% emulsifiable concentration)

Runoff from

nonregulated
small CAFO PA Turf 0.116 Fog/water shrew 0.004 0.048 0.009

Rice rat/star-nosed mole 0.003 0.044 0.007

Small mink 0.001 0.020 0.003 Large mink 0.002 0.022 0.003

Small river otter 0.002 0.024 0.003 Large river otter 0.001 0.013 0.002

Wash-off
from the skin
of 100 cows
that enter a body of

water NA 0.116 Fog/water shrew 0.005 0.067 0.012

Rice rat/star-nosed mole 0.005 0.062 0.009

Small mink 0.002 0.028 0.004 Large mink 0.002 0.030 0.004

Small river otter 0.002 0.033 0.004 Large river otter 0.001 0.019 0.002



### 6.1.2.3 Terrestrial (Upland and Semi-Aquatic) Plants

RQs for terrestrial (upland and semi-aquatic) pl ants for exposure via CAFO manure applied to
land or runoff from land to which CAFO manure has been applied were not calculated because

### 70 of the lack of terrestrial plant t oxicity data specific to coumaphos. Risk to plants from these two exposure pathways is discussed in the Risk Description section of this document.

6.1.2.4 Honey Bees (In-Hive Use)

RQs for honey bees exposed to coumaphos via im pregnated strips placed in hives to control
varroa mites and hive beetles were not calculated due to the lack of exposur e and/or toxicity data that is suitable for a quantita tive approach. Risk to honey bees from exposure to coumaphos is discussed in the Risk Descripti on section of this document.

6.1.3 Probit Slope Dose-Response Analys is of LOC and Acute RQ Values

As part of risk estimation, the Agency provides additional information on the potential for acute direct effects to exposed indi viduals in terms of the chan ce of an individual event ( i.e. , mortality or immobilization) should exposure at the EEC ac tually occur for a specie s with sensitivity to coumaphos on par with the acute toxicity endpo int selected for RQ ca lculation. This is accomplished using the slope of the dose-response relationship available from the toxicity study used to establish the acute toxicity measures of effect for each taxonomic group. The individual effects probability associated with the acute RQ is based on the mean estimate of the slope and an assumption of a probit dose-response relationsh ip. In addition to a single effects probability estimate based on the mean, upper and lower esti mates of the effects probability are also provided to account for variance in the slope, if available. Indi vidual effect probabilities are calculated based on an Excel spreadsheet to ol IECV1.1 (Individual Effect Chance Model Version 1.1) developed by U.S. EPA, OPP, E nvironmental Fate and Effects Division (June 22, 2004). The model provides the optio n of inserting taxa-specific probit slopes and confidence intervals. If specific informati on is not available, the model uses a default value of 4.5 for the probit slope and 2 and 9 for the upper and lower 95% confidence interval bounds.

Chances of effect ( e.g. , mortality, immobilization) for an in dividual organism are provided in

Table 6-21 (fish and aquatic invertebrates) and Table 6-22 (birds and mammals). For wash-off
from treated livestock that ente r bodies of water, this analysis was conducted using the RQ or LOC associated with 1 and 100 cows entering a body of water, depend ing on the taxon. The upper limit of 100 cows was selected based on literat ure indicating that a 6 foot deep, 1 acre farm pond would be suitable for watering 100 cows (Bray, 2013).

### 71 Table 6-21. Chance of Effect ( i.e. , Mortality or Immobilization) for an Individual Fish or Aquatic Invertebrate at Selected Acute Risk Quotient (RQ) or Level of Concern (LOC)* Values for Coumaphos

Taxon RQ or LOC* Probit Slope (95% C.I.) Chance of Effect

1 in... (95% C.I.)

Freshwater
fish LOC: Runoff 0.05 4.5 (2-9) (default) 4.18x10 8 (216-1.75x10 31 ) LOC: Wash-off for 1 cow entering a body of water 0.05 LOC: Wash-off for 100 cows entering a body of water 0.05

Estuarine/
marine fish LOC: Runoff 0.05 4.5 (2-9) (default) 4.18x10 8 (216-1.75x10 31 ) LOC: Wash-off for 1 cow entering a body of water 0.05 LOC: Wash-off for 100 cows entering a body of water 0.05

Freshwater
invertebrates RQ: Runoff from CAFO manure applied to land in

Texas RQ: Runoff from CAFO manure applied to land in the
rest of the U.S. 0.68

0.54

4.5 (2-9) (default) 4 (3-15)

9 (4-125)

RQ: Runoff from non-regulated small CAFO in Texas RQ: Runoff from non-regulated small CAFO in the
rest of the U.S. 3.4

3.9 1 (1-1) 1 (1-1)

RQ: Runoff from rangeland in Texas

LOC: Runoff from rangeland in the rest of the U.S. 0.07

0.05 9.88x10 6 (95-7.58x10 24 )

4.18x10 8 (216-1.75x10 31 ) RQ: Wash-off for 1 cow entering a body of water in

Texas RQ: Wash-off for 1 cow entering a body of water in
the rest of the U.S. 0.11

0.05 1.25x10 5 (37-3.19x10 17 )

4.18x10 8 (216-1.75x10 31 ) RQ: Wash-off for 100 cows entering a body of water
in Texas RQ: Wash-off for 100 cows entering a body of water
in the rest of the U.S. 11

5 1 (1-1)

1 (1-1)

Estuarine/
marine
invertebrates LOC: Runoff from CAFO manure applied to land 0.05

4.5 (2-9) (default) 4.18x10 8 (216-1.75x10 31 ) RQ: Runoff from non-regulated small CAFO in Texas

RQ: Runoff from non-regulated small CAFO in the
rest of the U.S. 0.13

0.15 2.99x10 4 (27-1.31x10 15 )

9.56x10 3 (21-1.65x10 13 ) LOC: Wash-off for 1 cow entering a body of water 0.05 4.18x10 8 (216-1.75x10 31 ) LOC: Runoff from rangeland

. 0.05 4.18x10 8 (216-1.75x10 31 ) RQ: Wash-off for 100 cows entering a body of water
in Texas RQ: Wash-off for 100 cows entering a body of water
in the rest of the U.S. 0.4

0.2 28 (5-5.85x10 3 )

1.21x10 3 (13-6.33x10 9 ) * listed species LOC (=0.05) was used for analys is when RQ(s) did not exceed listed species LOC

### 72 Table 6-22. Chance of Effect ( i.e. , Mortality) for an Individual Bird or Mammal at Selected Acute Risk Quotient (RQ) or Level of Concern (LOC)* Values for Coumaphos

Taxon RQ or LOC* Probit Slope (95% C.I.) Chance of Effect

1 in... (95% C.I.) Bird RQ: Dose-based exposure for primary exposure in Texas RQ: Dose-based exposure fo r primary exposure in the
rest of the U.S. 609

226

4.3 (1.2-7.3) (MRID 00112843) 1 (1-1) 1 (1-1)

LOC: Dose-based exposure for ingestion of bird carcasses (secondary exposure) 0.1 1.17x10 5 (9-6.95x10 12 ) RQ: Dose-based exposure for application of CAFO manure to land in Texas (small bird) RQ: Dose-based exposure for application of CAFO manure to land in the rest of the U.S. (small bird) 4.52

2.77 1 (1-1)

1 (1-1)

RQ: Dietary-based exposure for primary exposure 15 6.6 (3.9-9.7) (MRID 00112843) 1 (1-1) RQ: Dietary-based exposure for ingestion of bird carcasses (secondary exposure) 1.5 1 (1-1)

Mammal LOC: Dose-based exposure for ingestion of bird carcasses (secondary exposure) 0.1

4.5 (2-9) (default) 2.94x10 5 (44-8.86x10 18 ) RQ: Dose-based exposure for application of CAFO manure to land in Texas (small bird) RQ: Dose-based exposure for application of CAFO manure to land in the rest of the U.S. (small bird) 0.28

0.17 156 (8-3.07x10 6 )

3.74x10 3 (17-4.62x10 11 )

C.I. = confidence interval * listed species LOC (=0.1) was used for analysis when RQ did not exceed listed species LOC

### 73 6.2 Risk Description

The following risk description expl ains the overall direct effect conclusions regarding potential ecological risk from the various uses of coumaphos. The risk description takes into
consideration all lines of evid ence including: risk estimates ( i.e. , RQ results); information on the chance of individual effect ( i.e. , mortality or immobilization) for the acute RQ values; comparisons of non-definitive toxicity endpoints ( i.e ., >) to EECs; data from monitoring, field studies, and reported incidents that may provi de additional insights into the likelihood of exposure; and other factors that modify the likelihood of exposure such as timing of application, overlap of area affected and the degree of eff ect with the presence/absence of taxa, species sensitivity distribution, and pres ence/absence of dietary items.

6.2.1 Direct Effects to Aquatic Organisms

Risk to aquatic organisms from the followi ng four exposure pathways was estimated:

 uptake from surface waters receiving runoff fr om land to which contaminated manure has been applied;

 uptake from surface waters receiving r unoff from non-regulated small CAFOs ( i.e. , <300 animals);

 uptake from surface waters receiving runo ff from rangeland where treated livestock graze; and

 uptake from surface waters into which treated livestock wade ( i.e. , wash-off from treated
livestock that ente r bodies of water).

It should be noted that the possibility of an LOC exceedance for wash-off from treated livestock that enter bodies of water depends on the number of cows involved ( i.e. , the number of cows that must of wade into 1 acre, 6 foot deep body of wate r). A 6 foot deep, 1 acre farm pond is suitable for watering 100 cows (Bray, 2013). Therefore, 100 cows was used as a cut-off for determining that there may be a concern for risk from wash-o ff from treated livestock that enter bodies of

water.

6.2.1.1 Fish and Aquatic-Phase Amphibians

For fish, no acute or chronic LOCs (>0.05 and 1, respectively) are exceeded for exposure pathways involving runoff. In addition, hundreds of cows would need to enter a 1 acre, 6 foot deep body of water for there to be LOC exceedances. Probit slope dose-response analyses indicate a small chance of individual mortality ( i.e. , 1 in 4.18x10 8 

### ) for exposure via wash-off from cow entering a body of water and runoff fr om CAFO manure applied to land, non-regulated small CAFOs, or rangeland. Collectively, these anal yses indicate that the potential for risk to freshwater and estuarine/marine fish and aquati c-phase amphibians as a re sult of the registered uses of coumaphos on livestock is low.

6.2.1.2 Aquatic Invertebrates

Freshwater invertebrates are generally more sensitive to coumaphos than freshwater invertebrates, and there are mo re exceedances for freshwater invertebrates compared to their estuarine/marine counterparts.

### 74 For freshwater invertebrates in Texas and the rest of the U.S., acute and chronic LOCs for listed and non-listed species (>0.5 and 1, respectively) are exceeded for runoff from unincorporated CAFO manure applied to land and runoff from non-regulated small CAFO s. For runoff from rangeland, only the acute listed species LOC (0.05) is exceeded for Texas. Furthermore, only one to ten cows would have to enter a 1 acre, 6 f oot deep body of water for there to be acute and chronic LOC exceedances for listed and non-listed sp ecies of freshwater invertebrates. Probit slope dose-response analyses for the exposure pa thways yielding the highest RQs – runoff from non-regulated small CAFOS and wash-off from 100 cows entering a body of water – indicate a high chance of individual mortality ( i.e. , 1 in 1) for freshwater invertebrates.

For estuarine/marine invertebrates, the only ex ceedances for pathways involving runoff are for exposure via runoff from non-regulated small CA FOs for listed species. For wash-off from
treated cows that ente r bodies of water ( i.e. , 1 acre, 6 foot deep body of water), there are exceedances for acute exposure of listed species and chronic exposure of listed and non-listed species for 13 to 86 cows. Probit slope dose-re sponse analyses for the exposure pathways yielding the highest RQs – r unoff from non-regulated small CAFOS and wash-off from 100 cows entering a body of water – indicate a 1 in 9560 to 29,900 and 1 in 18 to 1210 chance of
individual morta lity, respectively.

The potential for risk to benthi c invertebrates was evaluated vi a the use of pore water EECs and toxicity data for freshwater i nvertebrates closely parallels that of the potential for risk to freshwater invertebrates. However, there is so me uncertainty associated with this conclusion since the toxicity endpoints used to calculat e RQs were generated from studies in which exposure occurred via the water colu mn instead of via sediment.

Collectively, these analyses imply that freshwat er, estuarine/marine, a nd benthic invertebrates may be adversely affected by the registered use of coumaphos on livestock. This conclusion is not unexpected given the conclusion s of previous assessments (see Section 2.2 ) as well as toxicity data indicating that invertebrates are exquisitely sensitive to coumaphos, which targets
invertebrates.

6.2.1.3 Aquatic Plants

For aquatic vascular plants, the listed species LO C (1) is not exceeded for runoff, regardless of the source of exposure, suggesti ng that concern for risk to list ed species from exposure via this pathway is low. RQs for non-list ed aquatic vascular plants were not calculated because the EC 50 

### endpoint is non-definitive ( i.e. , >166 μg/L). However, the EC 50 

### for aquatic vascular plants must be greater than the NOAEC of 166 μg a.i./L. Since there is no LOC exceedance using the NOAEC, concern for risk to non-listed aquatic va scular plants from exposure to coumaphos via runoff is also presumed low. The estimation of ri sk to aquatic vascular plants from exposure via
wash-off from treated livestock that enter bodies of water indi cates that over 1000 cows would have to wade into 1 acre, 6 foot deep body of wate r for there to be a concern for risk to aquatic vascular plants from exposure via this pathwa y which is unlikely. Colle ctively, these analyses imply that the concern for risk to aquatic vascul ar plants from the registered use of coumaphos
on livestock is low.

### 75 RQs for aquatic non-vascular plants for exposur e via runoff and wash-off were not calculated because of the lack of toxicity data specific to coumaphos. Instead, the most sensitive aquatic non-vascular plant toxicity endpoints for a surroga te organophosphate insecticide were compared to peak EECs for runoff and wash-off ( Tables 6-23 and 6-24 ). Aquatic non-vascular plant toxicity data are available for the several or ganophosphate insecticides including chlorpyrifos, diazinon, dichlorvos, dicrotophos, dimethoate, EPN, fenthion, naled, oxydemeton-methyl, phorate, and trichlorfon. Of the available data, naled is the most toxic to aquatic non-vascular plants. The most sensitive e ndpoints for naled are those for N. pelliculosa : EC 50 

### = 24 μg a.i./L and NOAEC = 4.2 μg a.i./L. For runoff, peak EECs do not exceed the toxicity endpoints for any
of the scenarios. For wash-off from the skin of treated livestock that enter bodies of water, hundreds of cows would need to wade into 1 acre, 6 foot deep body of water for the EECs to be greater than the endpoints for nale d. Collectively, these analyses indicate that the potential for risk to aquatic non-vascular plants as a result of the registered uses of c oumaphos on livestock is low. However, there is uncertain ty associated with this risk conclusion given that aquatic nonvascular plants may be more or less sensitive to coumaphos than to naled.

Table 6-23. Comparison of Aquatic Non-Vascul ar Toxicity Endpoints for Naled to Runoff

Estimated Environmental Concentrations (EECs) for Coumaphos + Coumaphoxon

PRZM/

EXAMS

Scenarios Sources of a.i. from Application

Scenario Wash-Off

Fraction Peak

EEC (μg/L) Naled

EC 50 (μg/L) Naled

NOAEC

(μg/L) Peak EEC

> EC 50 ? Peak EEC

>
NOAEC? Texas: Spray Application (42% flowable concentrate)

BSSTurf Runoff from CAFO manure applied to land (no incorporation) 0.02 0.05

24 4.2 No No Runoff from CAFO manure applied to land (incorporation) 0.02 0.0031

Runoff from nonregulated small CAFO 0.02 0.25

RangeBSS Runoff from rangeland 0.02 0.005 Rest of U.S.: Back Rubber Applicatio n (11.6% emulsifiable concentration)

PA Turf Runoff from CAFO manure applied to land (no incorporation) 0.027 0.04

24 4.2 No No Runoff from CAFO manure applied to land (incorporation) 0.027 0.0022

Runoff from nonregulated small CAFO 0.027 0.29

Runoff from rangeland 0.027 0.0013

### 76 Table 6-24. Comparison of Aquatic Non-Va scular Toxicity Endpoints for Naled to

Estimated Environmental Concentrations (EECs) for Coumaphos + Coumaphoxon for

Wash-Off from the Skin of Treated Li vestock That Enter Bodies of Water

Maximum Application Rate Wash-Off

Fraction Peak EEC (EEC/cow)

(μg/L) Naled

EC 50 (μg/L) Naled

NOAEC

(μg/L) Number of Cows

Needed to Exceed Toxicity Endpoint b
Type (lb a.i./ animal) (mg a.i./

ft 2 cow hide) Non-listed Listed

Texas: Spray Application (42% flowable concentrate) Single 0.027 274 0.02 0.008 24 4.2 3000 525 Rest of U.S.: Back Rubber Applicatio n (11.6% emulsifiable concentration) Single 0.01 101 0.02 0.004 24 4.2 6000 1050

a 1 acre, 6 foot deep body of water

b Toxicity endpoint/peak EEC



### 6.2.2 Direct Effects to Terrestrial Organisms

6.2.2.1 Birds, Reptiles, and Terrestrial-Phase Amphibians

Risk to birds from the following four exposure pathways was estimated:

 contact with/ingestion of hair and skin debris from treated cattle and/or contaminated soil
and feed in and around treatment areas (primary exposure);

 ingestion of contaminated bird carcasses (secondary exposure);

 ingestion of food items on land receiving manure from CAFOs; and

 ingestion of contaminated fish.

For primary exposure, avian acute dose- and dietary-based RQs of 226 to 609 and 4.5 to 15, respectively, exceed avian acute listed and non-listed species LO Cs (0.1 and 0.5, respectively). These RQs for avian primary exposure correspond to a 1 in 1 chance of individual mortality. For secondary exposure via the consumption of contamin ated bird carcasses, none of the avian acute dose-based RQs exceed acute LOCs. However, th e avian acute dietary-based RQs of 0.48 to 1.5 exceed avian acute non-listed and/or listed species LOCs. The highest RQ for avian secondary exposure corresponds to a high chan ce of individual mortality ( i.e. , 1 in 1). For ingestion of food items on land receiving manure from CAFOs, RQs for small and medium birds exceed the avian acute non-listed and/or listed sp ecies LOCs, and the highest RQs ( i.e. , those for small mammals) correspond to a 1 in 1 chance of individual mortalit y. For ingestion of contaminated fish, acute RQs exceed the listed species LOC for only sandpipers and rails.

Avian chronic RQs were not calculated due to the lack of chronic toxicity data for coumaphos. Instead, the most sensitive avian chronic to xicity endpoint for a surrogate organophosphate insecticide was compared direc tly to EECs for the three of the four exposure pathways ( Table 6-

25 ). Comparisons were not made for exposure via CAFO manure applie d to land because only acute EECs (in terms of LD 50 

### /ft 2 

### ) can be modeled for broadcast application of granules in TREX. Avian chronic, reproductive toxici ty data are available for the following phosphorothioates: fenitrothion, pa rathion, and methyl parathi on. Of the available data, parathion is the most toxic to birds on a chronic basis. The most sensit ive endpoint for parathion is that for mallard duck: NOAEC = 2.85 mg/kg-diet . EECs are greater than parathion’s chronic toxicity endpoint for exposure via hair and skin debris from treated cat tle and/or contaminated
soil and feed in and around treatment areas indica ting that birds may be at risk from chronic

### 77 exposure via this pathway. In contrast, dietar y-based EECs for secondary exposure via ingestion
of contaminated bird carcasses and fish contam inated via runoff or wash-off are less than the estimated chronic toxicity endpoint suggesting the concern for risk to birds via these pathways is low. However, there is uncertainty associated with these risk conclusi ons for chronic exposure given that birds may be more or less sensitive to coumaphos than to parathion on a chronic basis. It should be noted that previous assessments including the 1996 RED did not assess risk to birds from chronic exposure with the rationale being that significant acute exposure of birds to coumaphos would likely result in mortality befo re chronic effects could occur (USEPA, 1996).

Table 6-25. Comparison of an Avian Chronic Toxicity Endpoint for Parathion to Estimated Environmental Concentrations (EECs) for Coumaphos

Source of Exposure Wildlife Species EEC (mg/kg-diet) Parathion Chronic Toxicity Endpoint (mg/kg-diet) EEC > Toxicity Endpoint?

Hair and skin debris from treated
cattle and/or contaminated soil and
feed in and around treatment areas NA 1228

2.85 Yes 853

370

Contaminated bird carcasses (secondary exposure) NA 0.039

2.85 No 0.089

0.129 Texas: Fish contaminated via runoff Sandpipers 0.14

2.85 No Cranes 0.13

Rails 0.15

Herons 0.13 Small osprey 0.07 White pelican 0.04

Texas: Fish contaminated via washoff Sandpipers 0.45

2.85 No Cranes 0.40

Rails 0.48

Herons 0.41 Small osprey 0.22 White pelican 0.12

Rest of the U.S.: Fish contaminated
via runoff Sandpipers 0.16

2.85 No Cranes 0.14

Rails 0.17

Herons 0.15 Small osprey 0.08 White pelican 0.04

Rest of the U.S.: Fish contaminated
via wash-off Sandpipers 0.23

2.85 No Cranes 0.20

Rails 0.24

Herons 0.20 Small osprey 0.11 White pelican 0.06 NA = not applicable



### Collectively, these analyses imply that birds may be at risk from acute exposure via multiple pathways as a result of the regi stered use of coumaphos on livesto ck. This concern for risk to birds is supported by documented incide nts involving birds and coumaphos (see Section 5.3 ) and the conclusion of previous assessments (see Section 2.2 ).

### 78 It should be noted that the conclusions for risk from primary exposure vi a contact with/ingestion
of hair and skin debris from treated cattle and/or contaminated soil and feed in and around treatment areas and secondary expos ure via ingestion of contamin ated bird carcasses are based on EECs calculated using several conservative assumptions (see Section 4.3.1.2 ) and mean residues of coumaphos detected in bovine hair (a surrogate for poten tial contaminated food items) 1, 24, and 72 hours post-treatment as reporte d in the pilot field study (MRID 42512604).

In addition, there are several un certainties associated with ri sk estimates from exposure via ingestion of contaminated fish including the following:

 EECs for this pathway were determined using surface water and pore water EECs which were calculated using conservati ve assumptions described in Section 4.2

.

 In the absence of data, the metabolic rate constant for lower trophic levels was assumed to be zero. Metabolism of coumaphos by lower trophic levels w ould result in lower EECs and thus decreased estimates of risk ( i.e. , lower RQs).

6.2.2.2 Mammals

Risk to mammals from the following th ree exposure pathways was estimated:

 ingestion of contaminated bird carcasses (secondary exposure);

 ingestion of food items on land receiving manure from CAFOs; and

 ingestion of contaminated fish.

For secondary exposure via inge stion of contaminated bird carcasses, mammalian acute dosebased RQs (<0.01) do not exceed mammalian acute listed and non-listed species LOCs (0.1 and 0.5, respectively), and a probit dose-response analysis using th e listed species LOC of 0.1 indicates a relatively low chan ce of individual mortality ( i.e. , 1 in 2.94x10 5 

### ). In addition, mammalian chronic dose-based RQs (<0.01) for secondary exposure do not exceed the mammalian chronic LOC of 1. However, mamma lian chronic dietary-based RQs (1.5-3.2) for secondary exposure do exceed the mammalian chroni c LOC. For exposure via ingestion of food items on land receiving manure from CAFOs, ac ute RQs exceed the mammalian acute LOC (0.1) for listed species, and the highest RQs ( i.e. , those for small mammals) correspond to a 1 in 156 to
1 in 3.74x10 4 

### chance of individual mortality. For expos ure via ingestion of contaminated fish, there are no exceedances of LOCs. Collectively, these analyses imply that mammals may be at risk from chronic exposure via ingestion of contaminated bird carcasses (secondary exposure) and acute exposure via ingesti on of food items on land receiving manure from CAFOs as a result of the registered use of coumaphos on livestock. It should be noted that this conclusion contrasts with that of previous assessments because those assessments did not assess risk to mammals via contaminated bird carcasses or applic ation of CAFO manure to land.

Furthermore, it should be noted that the conc lusions for risk from secondary exposure via ingestion of contaminated bird carcasses were based on EECs calculated using several conservative assumptions (see Section 4.3.1.2 ) and mean residues of coumaphos detected in bovine hair (a surrogate for potential c ontaminated food items) 1, 24, and 72 hours posttreatment as reported in the pilot field study (MRID 42512604).

### 79 6.2.2.3 Terrestrial (Upland and Se mi-Aquatic) Plants

RQs for terrestrial (upland and semi-aquatic) pl ants for exposure via CAFO manure applied to
land or runoff from land to which CAFO manure has been applied were not calculated because of the lack of terrestrial plant toxicity data specific to coumaphos. Instead, the most sensitive terrestrial plant endpoints for a surrogate organo phosphate insecticide were compared to direct application and runoff EECs for CAFO manure ( Table 6-26 ). Terrestrial plan t toxicity data are available for the several organophosphate insecticid es including diazinon, di sulfoton, fosthiazate, isofenfos, and profenofos. Of the available data, pr ofenofos is the most toxi c to terrestrial plants. None of the EECs are greater than the toxicity endpoints for profenofos. This analysis indicates that the potential for risk to terrestrial (upla nd and semi-aquatic) plants as a result of the registered uses of coumaphos on livestock is low. However, there is uncer tainty associated with this risk conclusion given that terrestrial plants may be more or less sensitive to coumaphos.80Table 6-26. Comparison of Terrestrial Plant Toxicity Endpointsfor Profenofos to Estimated Environmental Concentrations(EECs) for CoumaphosSource of ExposureDirectApplicationEEC(lb a.i./A)Runoff EEC(lb a.i./A)Seedling Emergence(lb a.i./A)Vegetative Vigor(lb a.i./A)EEC >ToxicityEndpoint?All AreasDry(Upland)AreasSemiAquaticAreasMonocotDicotMonocotDicotEC25NOAECEC25NOAECEC25NOAECEC25NOAECTexas: Spray Application (42% flowable concentrate)CAFO manureapplied to landNoincorporationinto soil0.0150.0003 0.003>1 1 0.13 0.111 NA 1 NA 1NoIncorporationinto soil withina day0.00018 0.0018 NoRest of U.S.: Back Rubber Application (11.6% emulsifiable concentration)CAFO manureapplied to landNoincorporationinto soil0.00920.000184 0.00184>1 1 0.13 0.111 NA 1 NA 1NoIncorporationinto soil withina day0.000102 0.00102 NoNA = not applicable

### 81 6.2.2.4 Honey Bees (In-Hive Use)

RQs for honey bees exposed to coumaphos via im pregnated strips placed in hives to control
varroa mites and hive beetles were not calculated due to the lack of exposur e and/or toxicity data that is suitable for a quantitativ e approach. Instead, EECs in the fo rm of open literature data on coumaphos residues (mg/kg) det ected in bees and queen cells from hives treated with coumaphos-impregnated strips during controlled experiments (E066848) were compared to open literature data on the toxicity of coumaphos to bees ( Table 6-27 ). The NOAEC for exposure via queen cups (10 mg/kg) exceeds the lowest qu een cell EEC (8.11 mg/kg), and the LOAEC for exposure via queen cups (100 mg/kg) is within the range of queen cell EECs (8.11-237 mg/kg). In addition, the lowest LD 50 

### ’s (23.4, 24.2 mg/kg) are almost equal to the highest concentration of coumaphos detected in bees (23.26 mg/kg). This qualitative assessment indicates that there may be a concern for risk to honey bees from the regi stered in-hive use of coumaphos. It should be noted that the range of coumaphos EECs reported as part of a broad survey of pesticide residues
in commercial bee hives in North America (MRID 49497801) generally confirm concentrations measured during the controlled experiment inwhich hives were treated with coumaphosimpregnated strips.

Table 6-27. Comparison of A) Estimated En vironmental Concentrations (EECs) of Coumaphos and B) Coumaphos Toxicity Data for Honey Bees

A) EECs Sample Type Conc. (mg/kg) Source & Classification Queen cells 8.11-237 a E066848 Qualitative

Wax 12.69-120 a
0.001-91.9 b E066848 Qualitative

MRID 49497801

Bees 0.83-23.26 a
0.001-0.762 b E066848 Qualitative

MRID 49497801

Pollen 0.001-5.828 b MRID 49497801 B) Toxicity Data Route of Exposure Endpoint (mg/kg) Source & Classification

Queen cups 10-day NOAEC = 10 10-day LOAEC = 100 E100910 Quantitative E100380 Quantitative

Contact 24-hr LD 50 = 159.3 c E119503 Qualitative

Oral 8 day old bees: 48-hr LD 50 = 23.4 c 14 day old bees: 48-hr LD 50 = 24.2 c 3 day old bees: 48-hr LD 50 = 47.19 c E101175 Quantitative

a from hives treated with coumaphos-impregnated strips

b whether or not the samples were from hives that were treated with coumaphos is not known

a (LD 50 (μg/bee) / 128 μg/bee)*1000



### 6.3 Summary of Direct Effects

A summary of the direct effects of coumaphos to aquatic and terrestrial organisms is provided in

Tables 6-28 and 6-29

.82Table 6-28. Summary of Direct Effects for Aquatic OrganismsTaxonStatusConcernfor riskfromdirecteffects?*Basis for ConclusionRQ exceedance (type: acute and/or chronic)?Incidents?CommentsExposure pathways:Runoff from landto which CAFOmanure has beenappliedRunoff from nonregulated smallCAFOs (i.e., < 300animals)Runoff fromrangelandWash-off fromtreated livestockthat enter bodiesof waterFreshwater fishand aquatic-phaseamphibiansListedNoNoNoNoNoNo--Non-ListedNoNoNoNoNoEstuarine/marinefishListedNoNoNoNoNoNo--Non-ListedNoNoNoNoNoFreshwaterinvertebratesListedYesTexas,Rest of U.S.:Yes(acute & chronic)Texas,Rest of U.S.:Yes(acute & chronic)Texas: Yes(acute)Texas,Rest of U.S.:Yes(acute & chronic)No--Rest of U.S.: NoNonListedYesTexas,Rest of U.S.:Yes(acute & chronic)Texas,Rest of U.S.:Yes(acute & chronic)NoTexas,Rest of U.S.:Yes(acute & chronic)Estuarine/marineinvertebratesListedYesNoTexas,Rest of U.S.:Yes(acute)NoTexas,Rest of U.S.:Yes(acute & chronic)NoExposure via wash-off maynot be a complete exposurepathway given that thelikelihood of livestockentering estuarine/marinebodies of water is uncertainNonListedYesNoNoNoTexas,Rest of U.S.:Yes(chronic)Benthic(sedimentdwelling)invertebratesListedYesRQs not calculatedTexas,Rest of U.S.:Yes(acute & chronic)RQs not calculatedTexas,Rest of U.S.:Yes(acute & chronic)NoRQs were calculated usingpore water EECs and toxicityendpoints from water columnexposure studies withfreshwater invertebrates.Non-ListedYesTexas,Rest of U.S.:Yes(acute & chronic)Texas,Rest of U.S.:Yes(acute & chronic)Aquatic vascularplantsListedNoNoNoNoNoNo--Non-ListedNoNoNoNoNo83TaxonStatusConcernfor riskfromdirecteffects?*Basis for ConclusionRQ exceedance (type: acute and/or chronic)?Incidents?CommentsExposure pathways:Runoff from landto which CAFOmanure has beenappliedRunoff from nonregulated smallCAFOs (i.e., < 300animals)Runoff fromrangelandWash-off fromtreated livestockthat enter bodiesof waterAquaticnon-vascularplantsListedNARQs not calculatedNoThere is uncertaintyassociated with the riskconclusion as it is based on aqualitative analysis usingtoxicity data for a surrogateorganophosphate insecticide.NonListedNoNA = not applicable; no listed aquatic non-vascular plants* Direct or indirect effects to specific listed species have notbeen definitively determined; further investigation into temporal, geographical, and biological associations betweenthe registered uses and affected taxa is needed before definitive effects determinations can be made.84Table 6-29. Summary of Direct Effects for Terrestrial OrganismsTaxonStatusConcernfor riskfromdirecteffects?*Basis for ConclusionRQ exceedance (type: acute and/or chronic)?Incidents?CommentsExposure pathways:Hair and skindebris fromtreated cattleand/orcontaminated soiland feed in andaround treatmentareasContaminatedbird carcassesCAFOmanureapplied tolandRunoff fromland to whichCAFO manurehas been appliedContaminatedfishBirds, reptiles,andterrestrial-phaseamphibiansListedYesTexas,Rest of U.S.:Yes(acute)Texas,Rest of U.S.:Yes(acute)Texas,Rest ofU.S.:Yes(acute)NATexas,Rest of U.S.:Yes(acute; selectspecies)YesRQs were not calculated for chronicexposure due to the lack of avianchronic toxicity data. However, acomparison of EECs with an avianchronic toxicity endpoint for asurrogate organophosphateinsecticide indicates that there maybe a concern for risk from directeffects for exposure via:hair and skin debris from treatedcattle and/or contaminated soiland feed in and around treatmentareas; andcontaminated fish.There is uncertainty associated withthese risk conclusions for chronicexposure given the use of a toxicityendpoint for a surrogateorganophosphate insecticide.NonListedYesTexas,Rest of U.S.:Yes(acute)Texas,Rest of U.S.:Yes(acute)Texas,Rest ofU.S.:Yes(acute)NoMammalsListedYesNATexas,Rest of U.S.:Yes(chronic)Texas,Rest ofU.S.:Yes(acute)NANoNo --NonListedYesTexas,Rest of U.S.:Yes(chronic)NoNoTerrestrial(upland andListedNo RQs not calculated NoThere is uncertainty associated withthe risk conclusions as they are basedon a qualitative analysis using85TaxonStatusConcernfor riskfromdirecteffects?*Basis for ConclusionRQ exceedance (type: acute and/or chronic)?Incidents?CommentsExposure pathways:Hair and skindebris fromtreated cattleand/orcontaminated soiland feed in andaround treatmentareasContaminatedbird carcassesCAFOmanureapplied tolandRunoff fromland to whichCAFO manurehas been appliedContaminatedfishsemi-aquatic)plantsNonListedNotoxicity data for surrogateorganophosphate insecticide.Honey bees(in-hive use)ListedNA**NAYesThe risk conclusion is based on aqualitative analysis.Non-ListedYesNA = not applicable* * Direct or indirect effects to specific listed species havenot been definitively determined; further investigation into temporal, geographical, and biological associations betweenthe registered uses and affected taxa is needed before definitive effects determinations can be made.** Not applicable because the analysis for in-hive use only applies to honey bees which are non-listed.

### 86 6.4 Listed Species Effects Determinations

Based on this screening-level assessment, there ar e potential risks of di rect effects to listed aquatic invertebrates, birds, and mammals from the use of coumpahos on some of its registered use sites. Listed species of all taxa may also be affected through indirect effects because of the potential direct effects on liste d and non-listed species. Potentia l direct effects on listed fish, aquatic invertebrates, birds, and mammals from the use coumaphos may be associated with modification of Primary Constituent Elements (PCEs) of designated critical habitats, where such designations have been made. However, at this current stage of the Registration Review process, it is premature to make effects determinations fo r listed species until furt her scientific analysis and refinements are conducted, based on recomme ndations received from the National Academy of Sciences’ (NAS) National Research Council (NRC) April 2013 report, available at http://www.nap.edu/cata log.php?record_id=18344 . The NAS report outlines recommendations on specific scientific and technical issues re lated to the development of pesticide risk assessments that are compliant with the Endangered Species Act (ESA) and the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA).

The EPA along with the U.S. Fish & Wildlife Se rvice (USFWS), the National Marine Fisheries Service (NMFS) (collectively, the Services), a nd the U.S. Department of Agriculture (USDA), released a summary of their implem entation plan for assessing risks of pesticides to listed species ahead of the stakeholder workshop held on N ovember 15, 2013. This plan was developed in response to the NAS’ recommendations, including a common approach to ri sk assessment as a way of addressing scientific differences betw een EPA and the Services. During the workshop, the agencies received feedback from the public on the interim scientific approaches that were developed as part of the initial implementati on of the NAS recommendations. These approaches will be jointly implemented and vetted as part of a phased iterative process. Once fully vetted, EPA will further refine the listed species effects de termination portion of this risk assessment.

To make effects determinations for individual listed species, us eful refinements may include, but are not limited to, analyses of: 1) more detaile d, species-specific ecological and biological data; 2) more detailed and accurate information on coum aphos use patterns; and 3) sub-county level spatial proximity data for the co -occurrence of potential effects areas and listed species and any designated critical habitat. Examples of such refinements are described below.

EFED is currently developing tools that are expe cted to further refine the assessment and are designed to support effects determinations for individual federally list ed species and their designated critical habitats (w here applicable). Scientific information obtained from the Services, and other reliable s ources is being collated by EFED to address all currently listed species. This information is being stored in an Office of Pesticide Programs (OPP) Pesticide Registration Information SysteM (PRISM) listed species knowledgebase. The listed species knowledgebase consists of an information repos itory that houses biological and behavioral
information relevant to individual species ( e.g. , habitat, diet, and life history, including specific temporal and spatial associations) and a documen t repository that contains supporting documents ( e.g ., USFWS recovery plans) a nd electronic information ( e.g ., GIS data files). For terrestrial taxa, biological information re levant to the assessment ( e.g ., diet and body weight) will be used

### 87 to parameterize exposure estimates using a method c onsistent with currently used methods in the
T-REX and T-HERPS models.

Refinements will also include more detailed analyses of the registered uses and specific use patterns that result in either “Likely to Advers ely Affect” (LAA) or “Not Likely to Adversely Affect” (NLAA) determinations for federally li sted species. The analyses may include more information on where, when, and how coumaphos is used on all use sites. Actual usage data (when available) and national land-cover datasets that indi cate potential use sites [ e.g ., National Land Cover Dataset (NLCD), Cropland Data Laye r (CDL)] may be used to support a more refined analysis of where coumaphos is reasonabl y expected to be used. Similarly, refinements on the timing of applications and a more in-d epth exploration of ag ronomic practices for coumaphos may be included as part of the refinement.

The refinements based on individu al species data; additional, de tailed usage information, when available; and recommendations from the NRC re port are expected to help to more accurately identify potential areas of effect and to better inform effects and habitat determinations for listed species and any designate d critical habitats.



## 7 Uncertainties

A description of basic assumptions, uncertainties , strengths, and limitati ons of a typical risk assessment is described in Chapter 6 of the Agency’s Overview Document (USEPA, 2004) and includes those related to exposure for all taxa, those related to e xposure for aquatic species, those related to exposure for terrestrial animals, those related to the effects assessment, and those
associated with the acute LOC values. Additiona l uncertainties for this assessment are discussed
below.

7.1 Estimates of Exposure

In this risk assessment, EFED attempted to lo cate the best available data/models for estimating coumaphos residues in food items of non-target organisms, CAFO manure that applied to land, and potential runoff from CAFO s and rangeland. Frequently, such information is better expressed as ranges rather than points, and when this is the case, EFED typically opts to use the end of range which would result in the highest estimate of risk in order to ensure protection of ecological receptors and their habitats. Howeve r, EFED used wash-off fractions for the 24-hour drying time in this assessment because they repr esent a reasonable time frame after application for a treated cow to be caught in a rainstorm or enter a body of water. Potential exposure could be higher or lower depending on CAFO operatio ns such as an indoor or outdoor facility, numbers of cattle treated/day, and many other variables associ ated with manure managements for crop productions as well as weather conditions. Uncertainty associated with each of these individual components could potentially dictate higher or lower EECs.

7.2 Endocrine Disruptor Screening Program (EDSP)

As required under FFDCA section 408(p), EP A has developed the Endocrine Disruptor Screening Program (EDSP) to determine whether certain substances (inc luding pesticide active

### 88 and other ingredients) may have an effect in humans or wildlife si milar to an effect produced by a “naturally occurring estrogen, or other such endocrine effects as the Administrator may designate.” The EDSP employs a two-tiered ap proach to making the statutorily required
determinations. Tier 1 consists of a battery of 11 screening assays to identify the potential of a chemical substance to interact with the estroge n, androgen, and or thyroid (E, A, or T) hormonal systems. Chemicals that go th rough Tier 1 screening and are found to have the potential to interact with E, A, or T hormonal systems will proceed to the next stag e of the EDSP where EPA will determine which, if any, of th e Tier 2 tests are necessary base d on the available data. Tier 2 testing is designed to identify a ny adverse endocrine related eff ects caused by the substance, and establish a dose-response relationship between the dose and the E, A, or T effect.

Between October 2009 and February 2010, EPA issued test orders/data call-ins for the first group of 67 chemicals, which contains 58 pesticid e active ingredients and 9 inert ingredients.
This list of chemicals was selected based on th e potential for human exposure through pathways such as food and water, residen tial activity, and certain post-applic ation agricultural scenarios.
This list should not be construed as a lis t of known or likely e ndocrine disruptors.

Coumaphos was not among the group of 58 pesticid e active ingredients that received EDSP test orders. Additional information on the EDSP, including the policies and procedures, the list of 67 chemicals, the test guidelines and the Ti er 1 screening battery, can be found at http://www.epa.gov/scip oly/oscpendo/index.htm

.



## 8 References

Arnot, J.A. and F.A.P.C. Gobas. 2004. A food web bioaccumulation model for organic chemicals in aquatic ecosystems. Environmental Toxicology & Chemistry, 23 (10): 2343-2355.

ASAE. 2005. Manure Production and Characteristic s. ASAE Standard D384.1 FEB 03.American Society of Agricultural Engineers. St. Joseph, MI

Bray, D.R. 2013. Cooling Ponds for Dairy Cattle. University of Florida. IFAS Extension. Fact
sheet DS-96.

DP 347373. EFED Response to Comments for Coum aphos Registration Review Regarding Data Needed to Refine Ecological Ri sk Assessment. November 4, 2008.

DP 347376. Revised Registration Re view Preliminary Problem Fo rmulation for the Ecological
Risk Assessment of Co umaphos. April 28, 2008.

DP 393874. Review of Pollinator Data Requirement s and Efficacy Studies for In-Hive Uses of Coumaphos to Control Varroa Mites and the Small Hive Beetle. November 1, 2012.

DP 406398. Rationale for Not Recommending Request of and Additional Non-vascular Plant Study for Coumaphos. October 31, 2012.

### 89 Dunning, J.B. 1984. Body Weights of 686 Species of North American Birds. Wester Bird Banding Association. Monograph No. 1. May 1984.

E066848. Haarmann, T., Spivak, M., Weaver, D., Weaver, B., and Glenn, T. Effects of Fluvalinate and Coumaphos on Queen Honey Bees (Hymenoptera: Apidae) in Two Commercial Queen Rearing Operations. 2002. J. Econ. Entomol. 95(1): 28-35.

E100380. Collins, A. M., Pettis, J. S., Wilbanks, R ., and Feldlaufer, M. Performance of Honey Bee ( Apis mellifera ) Queens Reared in Beeswax Cells Impregnated with Coumaphos. 2004. J. Apic. Res. 43(3): 128-134.

E100910. Pettis, J. S., Collins, A. M., Wilbanks, R., and Feldlaufer, M. F. Effects of Coumaphos on Queen Rearing in the Honey Bee, Apis mellifera . 2004. Apidologie 35(6): 605-610.

E101175. Van Buren, N. W. M., Marien, A. G. H., O udejans, R. C. H. M., and Velthuis, H. H. W. Perizin, an Acaricid e to Combat the Mite Varroa jacobsoni : Its Distribution in and Influence on the Honeybee Apis mellifera . 1992. Physiol. Entomol. 17(3): 288-296.

E119503. Johnson, R. M., Pollock, H. S., and Bere nbaum, M. R. Synerg istic Interactions
Between In-Hive Miticides in Apis mellifera . 2009. J. Econ. Entomol. 102(2): 474-479.

FAO 2000. Food and Agriculture Organization of the United Nations. FAO PESTICIDE DISPOSAL SERIES 8. Assessing Soil Contamina tion: 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

Fest, C. and Schmidt, K-J. 1973. The Chemis try of Organophosphorus Pe sticides: Reactivity, Synthesis, Mode of Action, T oxicology. Springer-Verlag. 339 p.

Fletcher, J.S., J.E. Nellessen, and T.G. Pfleeger. 1994. Literature review and evaluation of the EPA food-chain (Kenaga) nomogram, an instrument for estimating pesticide residues on plants. Environmental Toxicology & Chemistry 13:1383-1391.

Hoerger, F. and E. E. Kenaga. 1972. Pe sticide Residues on Plants: Correlation of Representative Data as a Basis for Estimation of their Magnitude in the Environment. In F. Coulston and F. Korte, eds., Environmental Quality and Safety : Chemistry, Toxicology, and Technology, Georg Thieme Publ., Stuttg art, West Germany, pp. 9-28.

Koch, H. and P. Weiber. 1997. Exposure of honey b ees during pesticide application under field condition. Apidologie, 28: 439-447.

Murphy, J.P. and J.P. Harner. 2006. Lesson 22. Op en Lot Runoff Management. Livestock and Poultry Environmental Stewardship. http://www.lpes.org/les_plans.html

.

### 90 Pratt, M. and A.G. Rasmussen, 2001. Determining Your Stocking Rate. Ra nge Management Fact Sheet. NT+R/RM/04, Utah State University Coop erative Extension, Utah State University, Logan, UT

Tsuda, T., Kojima, M., Harada, H., Nakajima, A., Aoki, S. 1997. Acute toxicity, accumulation and excretion of organophosphorous insecticides and their oxi dation products in killifish. Chemosphere 53(5): 939-49.

USDA. 2008. Agricultural Waste Management Field Handbook, Part 651. Natural Resources Conservation Services, U.S. Departme nt of Agriculture, Washington, D.C.

USEPA. 1993a. Coumaphos: RED Consideration. Environmental Fate Effects Division. DP Number: D171764, D172064, D192569, D193395. U. S. Environmental Protection Agency. Washington, D.C.

USEPA. 1993b. Wildlife Exposure Handbook. Offi ce of Research and Development, United States Environmental Protection Agency.

USEPA. 1996. Reregistration Eligibility Decision (RED). Coumaphos. EPA 738-R-96-014. August 1996.

USEPA. 2004. Overview of the Ecological Risk Assessment Process in the Office of Pesticide Programs. United States Environmental Protectio n Agency (USEPA). Environmental Fate and
Effects Division. Office of Pes ticide Programs. Available at: http://www.epa.gov/espp/consultation/ecorisk-overview.pdf

US EPA. 2007. Coumaphos: Human Health Risk Assessment for Proposed Use on Honey and Honeycomb. PC Code: 036501; Petition Number: 2E6504; DP Number: D315769.

US EPA. 2009. Guidance for Selecting Input Pa rameters in Modeling th e Environmental Fate and Transport of Pesticides, Version II. U. S. Environmental Protection Agency. Washington,

D.C. http://www.epa.gov/oppefed1/models/water/

USEPA. 2010. Risks of Phosmet Use to the Federally Threatened and Endangered California Tiger Salamander (Ambystoma californiense). EFED. August 29, 1010. Available at: http://epa.gov/espp/litsta tus/effects/redleg-frog/2010/phosmet/assessment.pdf

USEPA. 2012a. Memorandum: NAFTA Guidance for Evaluating and Calculating Degradation
Kinetics in Environmental Media. Environmental Fate and Effects Division, Office of Chemical Safety and Pollution Prevention. U. S. Environmental Protection Agency.

USEPA. 2012b. White Paper in Support of th e Proposed Risk Assessment Process for Bees Submitted to the FIFRA Scientific Advisory Pa nel for Review and Comment. September 11,

2012.

### 91 

## 9 Bibliography of Cited MRIDs

Fate studies

00150197 Mallet, V.; Volpe, Y. (1978) Degradati on of Coumaphos in distilled water as function of pH. Analytica Chimica Acta 97:415-418.

00115166 Shmidl, J.; Kohlenberg, M.; Rainey, L. ; et al. (1981) Determination of the Rate of Disappearance of Coumaphos in Soil: Report No. 72226. (Unpublished study received Sep 23, 1982 under 11556-11; submitted by Bayvet, Shawnee Mission, KS; CDL: 248396-A)

00150619 Waggoner, T. (1985) Inclusion of Additional Data to Coumaphos- [carbon14] Accumulation and Persistence of Residues in Blue- gill: Bayvet Report No. 71632. Unpublished study prepared by Bayvet Division of Miles Laboratories, Inc. 4 p.

00159928 Waggoner, T. (1986) Hydrolysis of Carbon 14 Coumaphos in Sterile
Buffered Aqueous Solutions: Report No. 73320. Unpublished study prepared by Pharmacology and Toxicology Research Laboratory. 118 p.

00163806 Waggoner, T. (1986) Leaching of Ag ed Residues of [Carbon 14]-Coumaphos in Soil: Mobay Report No. 73431. Unpublished study pre- pared by Pharmacology & Toxicology Research Laboratory. 51 p.

40518701 Olson, G.; Lawrence, L. (1987) Coumaphos--Aerobic Soil Metabolism Study: PTRL Project No. 113. Unpublishe d study prepared by Pharmacology and Toxicology Research Laboratory. 49 p.

42512601 Judy, D.; Kaiser, F. (1992) Removal of Coumaphos Active Ingredient from Cattle Hides Treated with Co-Ral Emulsifiable Liquid Insecticide (E.L.I.): Lab Project Number: 40329. Unpublished study prepared by ABC Labs, Inc. 117 p.

42512602 Judy, D.; Kaiser, F. (1992) Removal of Coumaphos Active Ingredient from
Cattle Hides Treated with Co-Ral 25% Wettable Powder Insecticide: Lab Project Number: 40418. Unpublished study prepared by ABC Labs, Inc. 112

p.

42764101 Dykes, J. (1993) Determination of th e Aqueous Photodegradation of (carbon 14)-Coumaphos: Revised Final Report: Lab Project Number: 1224: 1224-1: 74413. Unpublished study prepared by Analytical Development Corp. 81 p.

42920301 Dykes, J. (1993) Determination of the Photodegradation of (14-C) Coumaphos on the Surface of So il: Lab Project Number: ADC 1223. Unpublished study prepared by Analytic al Development Corporation. 82 p.

### 92 43103901 Kelley, I.; Wood, S. (1994) Aque ous Photolysis of Coumaphos-- Identification of the Main Degrad ate: Lab Project Number: CS082401: 106221. Unpublished study prepared by Mile s Agricultural Division. 43 p.

43167401 Dykes, J. (1994) Determination of the Photodegradation of (carbon 14)- Coumaphos on the Surface of Soil: Char acterization of Bound Residues and Radioactivity Loss: Revision #1 to Final Research Report: Lab Project Number: 1223H-1: 74476. Unpublished study prepared by Analytical Development Corp. 33 p.

45721401 Mondel, M.; Hein, W. (2001) Adsorp tion/Desorption of Coumaphos-PhenylUL-(Carbon 14) and Its Degradate Coumaphos Oxon-Phenyl-UL-(Carbon 14) in Four Soil Types: Lab Project Number: 75259: BAC20: 151.006. Unpublished study prepared by Staatliche Lehr-und Forschungsanstalt fur. 80 p.

48705501 Dominic, A.; Arthur, E. (2011) [Phenyl-UL-(Carbon 14)]Coumaphos Oxon: Aerobic Soil Metabolism in Two Texas Soils. Project Number: MEAAY014, 152/484, 33974. Unpublished study prepared by Bayer CropScience. 99p.

Ecological effects studies

00022923 Hill, E.F., Heath, R.G., Spann, J.W., et al. (1975) Lethal Di etary Toxicities of Environmental Pollutants to Birds. By U. S. Fish and Wildlife Service, Patuxent Wildlife Research Center. Washington, D. C; USFWS (Special Scientific ReportWildlife No. 191).

00110597 Shmidl, J.; Rainey, L.; Kohlenberg , M. (1981) Oral LD50 Evaluation for Coumaphos Compound: Report No. 72212. (Unpublished study received on unknown date under 11556-4; submitted by Bayvet, Shawnee Mission, KS; CDL:248200-B)

00112840 Lamb, D.; Roney, D. (1980) Coumaphos T echnical Acute Toxicity to Bluegill and Rainbow Trout: Study Nos. 79A AB05 and 79AAR06; Report No. 71615. (Unpublished study received on unknown date under 11556-4; submitted by Bayvet, Shawnee Mission, KS; CDL: 248200-AN)

00112842 Carlisle, J.; Carsel, M. ; Lamb, D.; et al. (1982) Acute Dietary LC50 of Coumaphos Technical to Bobwhite Quail: Study N o. 82-175- 02; Report No. 72424. (Unpublished study received on unknown date under 11556-4; submitted by Bayvet, Shawnee Mission, KS; CDL:248200-AP)

00112843 Carlisle, J.; Carsel, M. ; Lamb, D.; et al. (1982) Acute Dietary LC50 of Coumaphos Technical to Mallard Du ck: Study No. 82-175- 01; Report No. 72409. (Unpublished study received on unknown date under 11556-4; submitted by Bayvet, Shawnee Mission, KS; CDL:248200-AQ)

00160000 Hudson, R.H., Tucker, R.K., Haegle, M.A. (1984) Handbook of Toxicity of
Pesticides in Wildlife. USDI Publication 153, Washington D.C.

### 93 05009242 Sanders, H.O. (1969) Toxicity of Pesticides to the Crustacean Gammarus
lacustris . Washington, D.C: U.S. Bureau of Sport Fisheries and Wildlife (U.S. Bureau of Sport Fisheries a nd Wildlife Technical Paper 25)

05017538 Sanders, H.O. (1972) Toxicity of Some Insecticides to Four Species of Malacostracan Crustaceans. Washington, D.C. : U.S. Department of the Interior, Fish and Wildlife Service (U.S. Bureau of Sport Fisheries and Wildlife Technical Paper No. 66.

40098001 Mayer, F.L., and Ellersieck, M.R. (1986) Manual of Acute Toxicity: Interpretation and Data Base for 410 Ch emicals and 66 Species of Freshwater Animals. USDI, FWS Public ation 160, Washington, D.C.

40228401 Mayer, F.L. (1986) Acute Toxicity Handbook of Chemicals to Estuarine Organisms. USEPA. OR D, Gulf Breeze, FL

41778503 Waggoner, T. (1990) Coumaphos--Acute LC50 Freshwater Invertebrate: Lab Project Number: COUM90A1. Unpublished study prepared by M.C. Bowman and Associates. 60 p.

41778504 Waggoner, T. (1990) Coumaphos--Acut e LC50 Freshwater Invertebrate ( Gammarus lacustris ): Lab Project Number: COUM90C: COUM90C1. Unpublished study prepared by M. C. Bowman and Associates. 46 p.

42512604 Corn, J.; Nettles, V. (1992) Coumaphos : Pilot Field Study to Evaluate Potential Toxicologic Effects in Wild Birds by Coumaphos Applicat ions to Livestock: Lab Project Number: SCWDS-001. Unpublished study prepared by The Univ. of Georgia. 51 p.

43061701 Eigenberg, D.; Elcock, L. (1993) A Two-generation Diet ary Reproduction Study in Rats Using Technical Grade Coum aphos: Lab Project Number: 91-672-JI: 74460. Unpublished study prepared by Miles, Inc. 1044 p.

43066301 Gagliano, G.; Bowers, L. (1993) Early Life Stage Toxicity of (carbon-14)- Coumaphos to the Rainbow Trout ( Oncorhynchus mykiss ) Under Flow-Through Conditions: Lab Project Number : 106245: CS842201. Unpublished study prepared by Miles Inc. 70 p.

43116601 Gagliano, G.; Fuss, M. (1994) Chronic Toxicity of (carbon 14)-Coumaphos to Daphnia magna Under Static Renewal Conditions: Lab Project Number: CS840701: 106410. Unpublished study prepared by Miles, Inc. 57 p.

45752810 Ellis, M. (1998) Evaluation of the Effi cacy of Coumaphos Impregnated Strips for the Control of Mites ( Varroa jacobsoni ) in Bee Colonies in Nebraska: Lab Project Number: 74969: 1160: 18461. Unpublis hed study prepared by University of Nebraska. 21 p. {OPPTS 810.3200}

45752811 Baxter, J. (1998) Evaluation of the E fficacy of Coumaphos Impregnated Strips for the Control of Mites ( Varroa jacobsoni ) in Bee Colonies in Guatemala: Lab Project Number: 74952: 1160: 150.484. Unpublished study prepared by USDA/ARS. 13 p. {OPPTS 810.3200}

### 94 45752812 Spivak, M. (1998) Evaluation of the E fficacy of Coumaphos Impregnated Strips for the Control of Mites ( Varroa jacobsoni ) in Bee Colonies in Minnesota: Lab Project Number: 74968: 1160: 150.525. Unpublished study prepared by University of Minnesota. 15 p. {OPPTS 810.3200}

45752813 Baxter, J. (1999) Control of the Small Hive Beetle ( Aethina tumida ): (Coumaphos): Lab Project Number: 74589: 75489: 1160. Unpublished study prepared by USDA/ARS. 7 p.

48322801 Banman, C.; Howerton, J.; Lam, C. (2010) Toxicity of Coumaphos Technical to Duckweed ( Lemna gibba G3) Under Static-Renewal Conditions. Project Number: EBAAY011, 9020, 152/413. Unpublished study prepared by Bayer CropScience. 74 p.

48322802 Banman, C.; Lam, C. (2010) Toxicity of Coumaphos to the Green Alga Pseudokirchneriella subcapitata . Project Number: EBAAY010, 9020, 152/412. Unpublished study prepared by Bayer CropScience. 72 p.

### 95 

## Appendix A: Example PRZM/EXAMS Output

Water Column
stored as TX R_02_E.out
Chemical: Coumaphos
PRZM environment: TurfBSS.txt, modified Wedday, 31 July 2013 at 14:00:27
EXAMS environment: pond298.exv, modified Tueday, 26 August 2008 at 06:14:08
Metfile: w13958.dvf, modified Tueday, 26 August 2008 at 06:14:44

Water segment con centrations (ppb)
Year Peak 96 hr 21 Day 60 Day 90 Day Yearly

1961 0.06 0.05 0.03 0.02 0.02 0.01

1962 0.11 0.09 0.06 0.04 0.04 0.02

1963 0.07 0.07 0.05 0.04 0.04 0.03

1964 0.21 0.18 0.11 0.08 0.07 0.05

1965 0.18 0.16 0.12 0.11 0.10 0.09

1966 0.14 0.13 0.11 0.10 0.10 0.09

1967 0.13 0.12 0.11 0.10 0.10 0.09

1968 0.13 0.12 0.11 0.10 0.10 0.10

1969 0.13 0.12 0.11 0.10 0.10 0.10

1970 0.19 0.17 0.14 0.12 0.11 0.10

1971 0.11 0.11 0.10 0.10 0.10 0.10

1972 0.15 0.13 0.11 0.10 0.10 0.09

1973 0.24 0.22 0.18 0.15 0.13 0.10

1974 0.23 0.20 0.16 0.13 0.13 0.12

1975 0.24 0.22 0.18 0.15 0.15 0.14

1976 0.21 0.20 0.17 0.15 0.15 0.14

1977 0.16 0.15 0.14 0.14 0.13 0.13

1978 0.19 0.18 0.15 0.13 0.13 0.12

1979 0.33 0.29 0.22 0.18 0.18 0.15

1980 0.19 0.19 0.17 0.16 0.16 0.15

1981 0.45 0.40 0.30 0.24 0.22 0.18

1982 0.25 0.24 0.21 0.20 0.20 0.19

1983 0.19 0.18 0.18 0.18 0.18 0.17

1984 0.17 0.16 0.16 0.16 0.16 0.15

1985 0.19 0.18 0.16 0.15 0.15 0.15

1986 0.23 0.22 0.18 0.16 0.16 0.14

1987 0.24 0.22 0.20 0.17 0.17 0.15

1988 0.16 0.16 0.15 0.15 0.15 0.14

1989 0.15 0.15 0.14 0.13 0.13 0.13

1990 0.17 0.16 0.14 0.13 0.13 0.12

Sorted results
Prob. Peak 96 hr 21 Day 60 Day 90 Day Yearly

0.03 0.45 0.40 0.30 0.24 0.22 0.19

### 96 0.06 0.33 0.29 0.22 0.20 0.20 0.18

0.10 0.25 0.24 0.21 0.18 0.18 0.17

0.13 0.24 0.22 0.20 0.18 0.18 0.15

0.16 0.24 0.22 0.18 0.17 0.17 0.15

0.19 0.24 0.22 0.18 0.16 0.16 0.15

0.23 0.23 0.22 0.18 0.16 0.16 0.15

0.26 0.23 0.20 0.18 0.16 0.16 0.15

0.29 0.21 0.20 0.17 0.15 0.15 0.14

0.32 0.21 0.19 0.17 0.15 0.15 0.14

0.35 0.19 0.18 0.16 0.15 0.15 0.14

0.39 0.19 0.18 0.16 0.15 0.15 0.14

0.42 0.19 0.18 0.16 0.15 0.13 0.13

0.45 0.19 0.18 0.15 0.14 0.13 0.13

0.48 0.19 0.17 0.15 0.13 0.13 0.12

0.52 0.18 0.16 0.14 0.13 0.13 0.12

0.55 0.17 0.16 0.14 0.13 0.13 0.12

0.58 0.17 0.16 0.14 0.13 0.13 0.10

0.61 0.16 0.16 0.14 0.12 0.11 0.10

0.65 0.16 0.15 0.12 0.11 0.10 0.10

0.68 0.15 0.15 0.11 0.10 0.10 0.10

0.71 0.15 0.13 0.11 0.10 0.10 0.10

0.74 0.14 0.13 0.11 0.10 0.10 0.09

0.77 0.13 0.12 0.11 0.10 0.10 0.09

0.81 0.13 0.12 0.11 0.10 0.10 0.09

0.84 0.13 0.12 0.11 0.10 0.10 0.09

0.87 0.11 0.11 0.10 0.08 0.07 0.05

0.90 0.11 0.09 0.06 0.04 0.04 0.03

0.94 0.07 0.07 0.05 0.04 0.04 0.02

0.97 0.06 0.05 0.03 0.02 0.02 0.01

0.10 0.25 0.24 0.21 0.18 0.18 0.17
Average of yearly averages: 0.11

Inputs generated by pe5.pl - Novemeber 2006

Data used for this run:
Output File: TX R_02_E

Metfile: w13958.dvf

PRZM scenario: TurfBSS.txt
EXAMS environment file: pond298.exv
Chemical Name: Coumaphos
Descripti

on Variable

Name Value Units Comments

Molecula r weight mwt 362.5 g/mol

### 97 Henry's

Law
Const. henry 2.62E-09 atm-m^3/mol

Vapor

Pressure vapr 1.00E-07 torr

Solubility sol 20 mg/L
Kd Kd mg/L
Koc Koc 5904 mg/L
Photolysi
s half-life kdp 1.38 days Half-life

Aerobic Aquatic
Metabolis

m kbacw 0 days Halfife

Anaerobi c Aquatic
Metabolis

m kbacs 0 days Halfife

Aerobic
Soil
Metabolis

m asm 0 days Halfife

Hydrolysi

s: pH 7 0 days Half-life

Method: CAM 1 integer See PRZM manual

Incorpora
tion Depth: DEPI cm

Applicati

on Rate: TAPP 0.009 kg/ha

Applicati

on Efficienc

y: APPEFF 1 fraction

Spray
Drift DRFT 0 fraction of application rate applied to pond

Applicati

on Date Date 15-01 dd/mm or dd/mmm or dd-mm or dd-mmm

Interval 1 interval 10 days Set to 0 or delete line for single app.

app. rate
1 apprate kg/ha

Interval 2 interval 10 days Set to 0 or delete line for single app.

app. rate
2 apprate kg/ha

Interval 3 interval 90 days Set to 0 or delete line for single app.

app. rate
3 apprate kg/ha

Interval 4 interval 10 days Set to 0 or delete line for single app.

app. rate
4 apprate kg/ha

Interval 5 interval 10 days Set to 0 or delete line for single app.

app. rate
5 apprate kg/ha

### 98 Interval 6 interval 90 days Set to 0 or delete line for single app.

app. rate
6 apprate kg/ha

Interval 7 interval 10 days Set to 0 or delete line for single app.

app. rate
7 apprate kg/ha

Interval 8 interval 10 days Set to 0 or delete line for single app.

app. rate
8 apprate kg/ha

Interval 9 interval 90 days Set to 0 or delete line for single app.

app. rate
9 apprate kg/ha

Interval

10 interval 10 days Set to 0 or delete line for single app.

app. rate
10 apprate kg/ha

Interval

11 interval 10 days Set to 0 or delete line for single app.

app. rate
11 apprate kg/ha

Record

17: FILTRA

IPSCND 1

UPTKF

Record

18: PLVKRT

PLDKRT

FEXTRC 0.5
Flag for
Index

Res. Run IR EPA
Pond

Flag for
runoff
calc. RUNOFF none none, monthly or total(average of entire run)

### 99 

## Appendix B: KABAM Analyses

Table B-1. Input Parameters for KABAM Modeling

Sources of a.i.

from Application

Scenario PRZM/

EXAMS

Scenario WashOff

Fraction Input Parameters

Water Column 21-day EEC (parent) (μg/L) (Coumaphos) Pore Water 21-day

EEC (parent)

(μg/L) (Coumaphos) Other Parameters

Texas: Spray Application (42% flowable concentrate) Log Kow = 4.3 Koc = 5904 L/kg OC

Km (fish) = 0.936*

Avian LD 50 = 2.4 mg/kg-bw
Avian LC 50 = 82.1 mg/kg-diet (bobwhite quail; MRID 00112843)

Avian NOAEC: No data

Mammalian LD 50 = 17 mg/kgbw (rat; MRID 00110597)

Mammalian NOAEC = 25 mg/kg-diet (rat; MRID 43061701) Runoff from non-regulated
small CAFO BSSTurf 0.02 0.25 0.17

Wash-off from
the skin of 100
cows that enter a body of

water NA 0.02 0.8 0.5

Rest of U.S.: Back Rubber Applicatio n (11.6% emulsifiable concentration)

Runoff from non-regulated
small CAFO PA Turf 0.116 0.29 0.19

Wash-off from
the skin of 100
cows that enter a body of

water NA 0.116 0.4 0.3

* Raw data from the BCF study was used to calculate a fish Km of 0.936/day

### 100 

## Appendix C: ECOTOX Literature Sea rch – Papers That Were Accepted

April 2012 refresh

1. Barnard, D. R.; Jones, B. G.; Rogers, G. D., and M ount, G. A. Acaricide Susceptib ility in the Lone Star Tick: Assay Techniques and Baseline Data. J. Econ. Entomol.; 1981; 74, (4): 466-469.
Notes: EcoReference No.: 113406 Chemical of Concern: AMZ,CBL,CMPH,CP Y,DZ,HCCH,MLN,MXC,PMR,PPCP,PSM,TVP,TXP

2. Bevk, D.; Kralj, J., and Cokl, A. Coumaphos Aff ects Food Transfer Between Workers of Honeybee Apis mellifera. Apidologie; 2012; 43, (4): 465-470.
Notes: EcoReference No.: 157842
Chemical of Concern: CMPH

3. Currie, R. W. and Gatien, P. Timing Acaricide Treatments to Preven t Varroa destructor (Acari: Varroidae) from Causing Economic Damage to Honey Bee Colonies. Can. Entomol.; 2006; 138, (2): 238-252.
Notes: EcoReference No.: 157767 Chemical of Concern: CMPH,FMA,TAUF

4. Damiani, N.; Gende, L. B.; Bailac, P.; Marcangeli, J. A., and Eguaras, M. J. Acaricidal and Insecticidal Activity of Essential Oils on Varroa destruct or (Acari: Varroidae) and Apis mellifera (Hymenoptera: Apidae). Parasitol. Res.; 2009; 106, (1): 145-152.
Notes: EcoReference No.: 155629 Chemical of Concern: CMPH,LAVDN,THYME,VFOIL

5. DeVaney, J. A. and Ivie, G. W. Systemic Activity of Coumaphos, Famphur, Crufomate, Ronnel, and Phosmet Given Orally to Hens for Control of the Northern Fowl Mite, Ornithonyssus sylviarum (Canestrini and Fanzago). Poult. Sci.; 1980; 59, 1208-1210.
Notes: EcoReference No.: 48673 Chemical of Concern: CMPH,PSM

6. Drummond, R. O. Susceptibility of the Cayenne Tick to Acaricides. J. Econ. Entomol.; 1981; 74, (4): 470-

472.
Notes: EcoReference No.: 113468 Chemical of Concern: AMZ,AsTO,CBL,CMPH,CPY,DDT,DZ,ETN,FNTH,HCCH,MLN,PPCP, PPHD,PSM,TCF,TVP,TXP

7. Drummond, R. O.; Gladney, W. J.; Whetstone, T. M., and Ernst, S. E. Laboratory Testing of Insecticides for Control of the Winter Tick. J. Econ. Entomol.; 1971; 64, (3): 686-688.
Notes: EcoReference No.: 113239
Chemical of Concern: As,CBL,CMPH,CPY,DZ,ETN,FNTH,HCCH,MLN,PPCP,PPHD,PPX,PSM,RTN,TCF,TVP,TXP

8. ---. Testing of Insecticides Ag ainst the Tropical Horse Tick in the Laboratory. J. Econ. Entomol.; 1971; 64, (5): 1164-1166.
Notes: EcoReference No.: 113240 Chemical of Concern: As,CBL,CMPH,CP Y,DZ,ETN,FNTH,HCCH,MLN,PPCP,PPHD,PPX, PSM,TCF,TVP,TXP

9. Elzen, P. J.; Westervelt, D., and Lucas, R. Form ic Acid Treatment for Control of Varroa destructor (Mesostigmata: Varroidae) and Safety to Apis mellifera (Hymenoptera: Apidae) Under Southern United States Conditions. J. Econ. Entomol.; 2004; 97, (5): 1509-1512.
Notes: EcoReference No.: 100404 Chemical of Concern: CMPH,FMA

### 101 10. Gregorc, A. and Ellis, J. D. Cell Death Localization In Situ in Laboratory Reared Honey Bee (Apis mellifera L.) Larvae Treated with Pesticides. Pestic. Biochem. Physiol.; 2011; 99, (2): 200-207.
Notes: EcoReference No.: 156418 Chemical of Concern: AMZ,CM PH,CPY,CTN,FVL,GYP,IMC,MYC,SZ

11. Gregorc, A.; Evans, J. D.; Scha rf, M., and Ellis, J. D. Gene Expression in Honey Bee (Apis mellifera) Larvae Exposed to Pesticides and Varroa mites (Varroa destru ctor). J. Insect Physiol.; 2012; 58, (8): 1042-

1049.
Notes: EcoReference No.: 157769 Chemical of Concern: AMZ,CM PH,CPY,CTN,FVL,GYP,IMC,MYC,SZ

12. Johnson, R. M.; Pollock, H. S., and Berenbaum, M. R. Synergistic Inte ractions Between In-Hive Miticides in Apis mellifera. J. Econ. Ento mol.; 2009; 102, (2): 474-479.
Notes: EcoReference No.: 119503 Chemical of Concern: CMPH,PPB,TAUF,TBF

13. Karabacak, M.; Kanbur, M.; Eraslan, G., and Sarica, Z. S. The Antioxidant Effect of Wheat Germ Oil on Subchronic Coumaphos Exposure in Mice. Ecotoxic ol. Environ. Saf.; 2011; 74, (7): 2119-2125.
Notes: EcoReference No.: 157622
Chemical of Concern: CMPH

14. Kitchin, K. T. and Brown, J. L. Biochemical Studies of Promoters of Carcinogenesis in Rat Liver. Teratog. Carcinog. Mutagen.; 1989; 9, (5): 273-285.
Notes: EcoReference No.: 103823 Chemical of Concern: CMPH,EDTA,MRX,TXP

15. Koch, H. G. and Burkwhat, H. E. Susceptibility of the American Dog Tick (Acari: Ixodidae) to Residues of Acaricides: Laboratory Assays. J. Econ. Entomol.; 1983; 76, (2): 337-339.
Notes: EcoReference No.: 113231 Chemical of Concern: AMZ,ATN,BDC,CB L,CHD,CMPH,CPY,DZ,FN TH,HCCH, MLN,MXC, Naled,PMR,PPCP,PPX, PSM,RSM,RTN,TCF,TVP,TXP

16. Miller, J. E. Epidemiology an d Economics of Strongylate Nematode Parasites of the Bovine in Central California. Ph.D. Thesis, University of California, Davis, CA; 1983: 217 p. (UMI# 407917).
Notes: EcoReference No.: 157924 Chemical of Concern: CMPH,TBA

17. Miller, R. W.; Gordon, C. H.; Morgan, N. O.; Bowman, M. C., and Beroza, M. Coumaphos as a Feed Additive for the Control of House Fly Larvae in Cow Manure. J. Econ. Entomol.; 1970; 63, (3):

853-855.
Notes: EcoReference No.: 103849
Chemical of Concern: CMPH

18. Robbins, W. E.; Hopkins, T. L., and Darrow, D. I. Synergistic Action of Piperonyl Butoxide with Bayer 21/199 and Its Corresponding Phosphate in Mice. J. Econ. Entomol.; 1959; 52, 660-663.
Notes: EcoReference No.: 157619 Chemical of Concern: CMPH,CMPO,PPB

19. Smodis Skerl, M. I. and Gregorc, A. Heat Shock Proteins and Cell Death In Situ Localisation in Hypopharyngeal Glands of Honeybee (Apis mell ifera carnica) Workers After Imidacloprid or Coumaphos Treatment. Apidologie; 2010; 41, (1): 73-86.
Notes: EcoReference No.: 157832 Chemical of Concern: CMPH,IMC

20. Su, M. Q.; Kinoshita, F. K.; Fr awley, J. P., and DuBois, K. P. Comp arative Inhibition of Aliesterases and

### 102 Cholinesterase in Rats Fed Eighteen Organophosphorus Insecticides. Toxicol. Appl. Pharmacol.; 1971; 20, (2): 241-249.
Notes: EcoReference No.: 38991 Chemical of Concern: AZ,CMPH,DEM,DMT,DS,EPRN,ETN,FNTH,MLN,MP,MVP,PRN

21. Takagi, H. and Block, E. Effects of Feeding Coumaphos to Dairy Cows at Various Stages of Lactation on
Subclinical Parasite Infection and Milk Production. Can. J. Anim. Sci.; 1986; 66, (1): 141-150.
Notes: EcoReference No.: 101801
Chemical of Concern: CMPH

22. White, R. D. Mutagenic and Toxicologic Implications of Pyrrolizidine (Senecio) Alkaloids. Ph.D. Thesis, Oregon State University, OR; 1983: 105 p. (UMI# 8227585) (Publ. in part as 118136, 157929).
Notes: EcoReference No.: 157925 Chemical of Concern: CBL,CMPH,Cu,MLN,PPCP



### April 2008 search

1. Astroff, A. B.; Freshwater, K. J., and Eigenberg, D. A. Comparative Organ ophosphate-Induced Effects Observed in Adult and Neonatal Sp rague-Dawley Rats During the Conduct of Multigeneration Toxicity Studies. Reprod. Toxicol.; 1998; 12, (6): 619-645.
Notes: EcoReference No.: 88895 Chemical of Concern: TCF,TBF,OXD,FMP,CMPH

2. Brody, G. and Elward, T. E. Comparative Activity of 29 Known Anthelmintics Under Standarized Drug-Diet and Gavage Medication Regimens Against Four Helminth Species in Mice. J. Parasitol.; 1971; 57, (5): 1068-1077.
Notes: EcoReference No.: 101241
Chemical of Concern: DDVP,CMPH,NSM,TBA,TCF

3. Carlson, C. A. Effects of Three Organophosphorus Insecticides on Immature Hexagenia and Hydropsyche of the Upper Mississippi River. Trans. Am. Fish. Soc.; 1966; 95, (1): 1-5.
Notes: EcoReference No.: 2158 Chemical of Concern: CMPH,MLN

4. Collins, A. M.; Pettis, J. S.; Wilbanks, R., and Fe ldlaufer, M. Performance of Honey Bee (Apis mellifera) Queens Reared in Beeswax Cells Impregnated with Coumaphos. J. Apic. Res.; 2004; 43, (3): 128-

134.
Notes: EcoReference No.: 100380
Chemical of Concern: CMPH

5. Cox, D. D.; Mullee, M. T., and Allen, A. D. Anthelmintic Activity of Two Organic Phosphorus Compounds, Coumaphos and Naphthalophos, Against Gastrointestinal Nematodes of Cattle. Am. J. Vet. Res.; 1967; 28, (122): 79-88.
Notes: EcoReference No.: 100916
Chemical of Concern: CMPH

6. ---. Cattle Grub Control with Feed Additives (Coumaphos and Fenthion) and Pour-ons (Fenthion and Trichlorfon). J. Econ. Entomol.; 1967; 60, (2): 522-527.
Notes: EcoReference No.: 101195 Chemical of Concern: TCF,FNTH,CMPH

7. ---. Effect of Coumaphos and Fenthion Feed Add itives on Gastrointestinal Nematode Egg Counts in Feedlot Cattle. Am. J. Vet. Res.; 1969; 30, (11): 1933-1943.
Notes: EcoReference No.: 100914 Chemical of Concern: CMPH,FNTH

### 103 8. Davis, H. C. and Hidu, H. Effects of Pesticides on Embryonic Development of Clams and Oysters and on Survival and Growth of the Larvae. Fish. Bull.; 1969; 67, (2): 393-404.
Notes: EcoReference No.: 2400 Chemical of Concern: EDT,24DXY,AZ,CBL,CMPH,DS,DU,HCCH,MLN,PCP,PRN, DDT,NaPCP, DZ, DBAC,DCB,TCC

9. Dawe, D. L.; Brown, J.; Davis, R. B., and Kellogg, F. E. Effectiveness of Mare tin and Meldane as Treatments for Capillariasis in Bobwhites. Av ian Dis.; 1969; 13, (3): 662-667.
Notes: EcoReference No.: 101108
Chemical of Concern: CMPH

10. Elzen, P. J. Suitability of Formic Acid to Contro l Varroa destructor and Safe ty to Apis mellifera in the Southwestern U.S. Southwest. Entomol.; 2003; 28, (4): 261-266.
Notes: EcoReference No.: 101098 Chemical of Concern: FMA,CMPH,FVL

11. Faulkner, L. C.; Carroll, E. J. , and Benjamin, M. Effect of Coumaphos on Bulls. J. Am. Vet. Med. Assoc.; 1964; 145, (5): 456-459.
Notes: EcoReference No.: 101192
Chemical of Concern: CMPH

12. Folz, S. D.; Pax, R. A.; Thomas, E. M.; Bennett, J. L.; Lee, B. L., and Conder , G. A. Detecting In Vitro Anthelmintic Effects with a Micromotility Meter. Vet. Parasitol.; 1987; 24, (3/4): 241-250.
Notes: EcoReference No.: 101182
Chemical of Concern: CMPH

13. ---. Development and Validation of an In Vitro Trichostrongylus colubriformis Motility Assay. Int. J. Parasitol.; 1987; 17, (8): 1441-1444.
Notes: EcoReference No.: 101170
Chemical of Concern: CMPH

14. Glenn, J. S.; Baker, N. F.; Franti, C. E., and Ve r Steeg, J. D. Anthelmintic Tr eatment of Nonpastured Dairy Cows in California. J. Dairy Sci.; 1982; 65, (10): 2006-2010.
Notes: EcoReference No.: 101239
Chemical of Concern: CMPH

15. Haarmann, T.; Spivak, M.; Weaver , D.; Weaver, B., and Glenn, T. Eff ects of Fluvalinate and Coumaphos on Queen Honey Bees (Hymenoptera: Apidae) in Two Commercial Queen Rearing Operations. J. Econ. Entomol.; 2002; 95, (1): 28-35.
Notes: EcoReference No.: 66848 Chemical of Concern: FVL,CMPH

16. Heath, R. G. ; Spann, J. W.; H ill, E. F., and Kreitzer, J. F. Comparative Dietary T oxicities of Pesticides to Birds. pecial Scientific Report Wildlife 152, Bureau of Sport Fisheries and Wildlife, U.S. Department of the Interior, Washington, DC; 1972: 57 p.
Notes: EcoReference No.: 35214 Chemical of Concern: TMP,AND,AMTL,ATZ,PPX,Captan,CHL,CHD,TCF,24DXY,DDT,24DB, DDVP,DEM,DEZ,DBN,DCF,DLD,DS,CU,CPY,DMT,SZ,FNF,ES,EN,TXP,FNT,FNTH,AZ,HPT,P SM,HCCH,MLN,MCPB,MTAS,MOM,MXC,MP,MRX, Nabam,Naled,OXC,PRN,PCP,PRT,PPHD, PCL,TFM,THM,PPG,CMPH,OXD,DZ

17. Hill, E. F. and Camardese, M. B. Lethal Dietary Toxicities of Environmental Contaminants and Pesticides to Coturnix. Lethal Dietary Toxicities of Environmental Contaminants and Pesticides to Coturnix; 1986: 147 p.
Notes: EcoReference No.: 50181

### 104 Chemical of Concern: 24D,24DXY,ACP,ADC,AMSV,AMTL,AND,ARM,ATN,ATZ,AZ,BMC, BMN,BMY,Captan,CBF,CBL,CdCl,CHD,CMPH,CPY,CPYM,CrS,DBN,DCF,DCTP,DDT,DDVP, DEM,DFPM,DINO,DLD,DMB,DMT,DQTBr,DS,DU,DZ,EN,EP,ES,ETN,FMP,FNF,FNT,FNTH,F TTCl,GYP,HCCH,HgCl2,HPT,IFP,K2Cr207,L NR,Maneb,MCB,MCPB,MDT,MLN,MLT,MOM,M P,MRX,MSMA,MTAS,MTM,MVP,MXC,Naled,Ni ,OXD,Pb,PbN,PCB,PCL,PCP,PHSL,PMR,PPB, PPHD,PPN,PPX,PQT,PRN,PRT,PSM,PYN,RSM,R TN,SPS,SZ,TBO,TCF,TEPP,TFN,THM,TMP,T VMP, TVP,V,Zineb,Ziram,ZnP

18. Hill, E. F.; Heath, R. G.; Spann, J. W., and W illiams, J. D. Lethal Dietary Toxicities of Environmental Pollutants to Birds. U.S.Fish and Wildl.Serv.No.191, Special Scientific Report-Wildlife; 1975: 61 p.
Notes: EcoReference No.: 35243 Chemical of Concern: 24DXY,TMP,ADC,AM TL,AND,ATZ,Captan,CBF ,CBL,Cd,Cr,DDT,DLD, DMT,DS,DU,DZ,ES,ETN,FNT,HCCH,Hg,HPT,MCPB,MLN,MP,MRX,MTAS,MXC,Naled,Pb,PC B,PCL,PCP,PQT,PRN,PRT,PYN,RSM,RTN,SZ,T FM,THM,TVP,TXP,Zn,ZnP,As,AZ,OXD,PSM,L NR,PPG,CYP,PEM,MOM,DDVP,PHTH,DBN,CMPH,TVPM

19. Hudson, R. H.; Tucker, R. K., an d Haegele, M. A. Handbook of Toxicity of Pesticides to Wildlife. Resource Publication 153, Fish and Wildlife Service, U.S. Department of the Interior; 1984: 90 p.
Notes: EcoReference No.: 50386 Chemical of Concern: ACP,ACL,ACR,ADC ,AND,ATN,AMTL,ANZ,A TZ,4AP,AZ,PPX,BTY, Captan,CBL,CBF,CHD,CQTC,CPY,CMPH,CZE, 24D,DDT,DDVP,DEF,DEM,DZ,DBN,DLN,DCF, DCTP,DLD,DMT,DQTBr,DS,DU,ES,EDT,EN,EP, ETN,FNT,FNTH,FMV,Folpet,FNF,HPT,PSM,H CCH,MLN,MDT,MCB,MOM,MTPN,MXC,MP,MVP, MRX,NABAM,Naled,FMP,PQT,PRN,PCP,P RT,PCL,PSM,RTN,STAR,STCH,TCDD,TMP,TZL, TVP,TZL,THM,TXP,TCF,TFN,ZnP,Zineb,PC

B

20. Katz, M. Acute Toxicity of Some Organic Insecticides to Three Species of Salmonids and to the Threespine Stickleback. Trans. Am. Fish. Soc.; 1961; 90, (3): 364-368.
Notes: EcoReference No.: 522 Chemical of Concern: CMPH,TXP,AND,D LD,DDT,HCCH,MXC,HPT,CHD,EN,AZ,MLN,CBL

21. Knapp, F. W. The Effect of Free-Choice Coumaphos Salt Mixtures on Cattle and Cattle Parasites. J. Econ. Entomol.; 1965; 58, (2): 197-199.
Notes: EcoReference No.: 101238
Chemical of Concern: CMPH

22. Landrum, P. F.; Fisher, S. W.; Hwang, H., and Hickey, J. Hazar d Evaluation of Ten Organophosphorus Insecticides Against the Midge, Chironomus ripa rius via QSAR. MOR. P.F.Landrum, Great Lakes Environmental Research Laboratory, NOAA, Ann Arbor, MI, 48105: SAR QSAR Environ.Res.; 1999; 10, (5): 423-450.
Notes: EcoReference No.: 67687 Chemical of Concern: FNF,TBO,CMPH,DCTP,FNTH,AZ,CPY,DZ,DS

23. Leland, S. E. Jr.; Ridley, R. K.; Dick, J. W.; Slonka, G. F., and Zimmerman, G. L. Anthelmintic Activity of Trichlorfon, Coumaphos, and Naphthalophos Agai nst the In Vitro Grown Parasitic Stages of Cooperia punctata. J. Parasitol.; 1971; 57, (6): 1190-1197.
Notes: EcoReference No.: 101240 Chemical of Concern: TCF,CMPH

24. Maronpot, R. R.; Shimkin, M. B.; Witschi, H. P.; Smith, L. H., and Cline, J. M. Strain A Mouse Pulmonary Tumor Test Results for Chemicals Previously Tested in the National Cancer Institute Carcinogenicity Tests. MOR,PHYINJECT; 1986; 76, (6): 1101-1112.
Notes: EcoReference No.: 91262 Chemical of Concern: Captan ,DZ,PRN,AND,EDB,TXP,CMPH,DNT

25. Miller, J. E.; Baker, N. F., and Farver, T. B. Anthelmintic Treatment of Pastured Dairy Cattle in California.

### 105 Am. J. Vet. Res.; 1986; 47, (9): 2036-2040.
Notes: EcoReference No.: 101152 Chemical of Concern: TBA,CMPH

26. Miller, R. W. and Long, P. P. Effect of Feeding Co umaphos on Feed Intake and Rate of Gain of Steers. J. Dairy Sci.; 1974; 57, (6): 723-725.
Notes: EcoReference No.: 37967
Chemical of Concern: CMPH

27. National Cancer Institute. Bioassay of Coumaphos for Possible Carcinogenicity. NCI Tech.Rep.Ser.#96, Natl.Cancer Inst., Bethesda, MD; 1979: 100 p.
Notes: EcoReference No.: 100567
Chemical of Concern: CMPH

28. Nelson, D. L.; Mozier, J. O.; White, R. G., and Allen, A. D. The Pharmaco logical Effect of Baymix (Coumaphos) on Poultry. Poult. Sci.; 1968; 47, (3): 960-962.
Notes: EcoReference No.: 101256
Chemical of Concern: CMPH

29. Pardio, V. T.; De Ibarra, N. J.; Waliszewski, K. N., and Lopez, K. M. Effect of Coumaphos on Cholinesterase Activity, Hematology, and Biochemical Blood Parameters of Bovines in Tropical Regions of
Mexico. J. Environ. Sci. Health Part B: Pestic . Food Contam. Agric. Wastes; 2007; 42, (4): 359-

366.
Notes: EcoReference No.: 100839
Chemical of Concern: CMPH

30. Pardio, V. T.; Ibarra, N.; Rodriguez, M. A., an d Waliszewski, K. N. Use of Cholinesterase Activity in Monitoring Organophosphate Pesticide Exposure of Cattle Produced in Tropical Areas. J. Agric. Food Chem.; 2001; 49, (12): 6057-6062.
Notes: EcoReference No.: 100382 Chemical of Concern: FNTH,CMPH

31. Pettis, J. S.; Collins, A. M.; Wilbanks, R., and Feld laufer, M. F. Effects of Co umaphos on Queen Rearing in the Honey Bee, Apis mellifera. Apidologie; 2004; 35, (6): 605-610.
Notes: EcoReference No.: 100910
Chemical of Concern: CMPH

32. Rettich, F. Laboratory and Field Investigations in Czechoslovakia with Fen itrothion, Pirimiphos-Methyl, Temephos and Other Organophosphorous Larvicides. Mosq. News; 1979; 39, (2): 320-328 (Author Communication Used).
Notes: EcoReference No.: 5162 Chemical of Concern: CPY,DZ,MLN,CMPH,DMT,Naled,DDT,FNT,PIRM,TMP,TCF,DDVP,TVP

33. Sanchez-Fortun, S.; Sanz-Barrera , F., and Barahona-Gomariz, M. V. Acute Toxicities of Selected Insecticides to the Aquatic Arthropod Artemia salina. Bull. Environ. Contam. Toxicol.; 1995; 54, (1): 76-82.
Notes: EcoReference No.: 14997 Chemical of Concern: CMPH,AZ,DDVP,DDT,DLD,HCCH

34. Sanders, H. O. Toxicity of Some Insecticid es to Four Species of Ma lacostracan Crustaceans. Tech.Pap.No.66, Bur.Sports Fish.Wildl., Fish Wild l.Serv., U.S.D.I., Washington, D.C.; 1972: 19 p. (Publ in Part As 6797).
Notes: EcoReference No.: 887 Chemical of Concern: ATN,ES,AZ,MLN,MXC,Naled,DS,PRT,CBL,DLD,EN,CHD,AND,DDT, TXP,HPT,CPY,CMPH,OXD,DZ

### 106 35. Silvestri, R.; Himes, J. A., and Edds, G. T. Repeated Oral Administration of Coumaphos in Sheep: Effects on Erythrocyte Acetylcholinesterase and Other Constituen ts. Am. J. Vet. Res.; 1975; 36, (3): 283-287.
Notes: EcoReference No.: 38777
Chemical of Concern: CMPH

36. Van Buren, N. W. M.; Marien, A. G. H.; Oudejans, R. C. H. M., and Velthuis, H. H. W. Perizin, an Acaricide to Combat the Mite Varroa jacobsoni: Its Distribution in and Influence on the Honeybee Apis mellifera. Physiol. Entomo l.; 1992; 17, (3): 288-296.
Notes: EcoReference No.: 101175
Chemical of Concern: CMPH

37. Weick, J. and Thorn, R. S. Effects of Acute Sublethal Exposure to Coumaphos or Diazinon on Acquisition
and Discrimination of Odor Stimuli in the Ho ney Bee (Hymenoptera: Ap idae). MOR,BCM,BEH. J.Weick, Dep. of Biol., Denison Univ., Granville, OH 43203: J. Econ. Entomol.; 2002; 95, (2): 227-

236.
Notes: EcoReference No.: 87972 Chemical of Concern: CMPH,DZ

38. Willford, W. A. Toxicity of 22 Therapeutic Compounds to Six Fishes. Invest.Fish Control No.18, Resourc.Publ.No.35, Fish Wildl.Se rv., Bur.Sport Fish.Wildl., USDI, Washington, DC; 1966: 10 p.
Notes: EcoReference No.: 2524 Chemical of Concern: CMPH,Ni,DBAC

39. Wilton, D. P.; Fetzer, L. E. Jr., and Fay, R. W. Insecticide Baits for Anopheline Larvae. Mosq. News; 1973; 33, (2): 198-203.
Notes: EcoReference No.: 13956 Chemical of Concern: FNTH,FNT,C MPH,CBL,MXC,MCB,CPY,RSM,CPYM,TMP

### 107 

## Appendix D: ECOTOX Literature Se arch – Papers That Were Not Acceptable

April 2012 refresh

1. Alabaster, J. S. Survival of Fish in 164 Herbicides, Insecticides, Fungicides, Wetting Agents and Miscellaneous Substances. MORAQUA; 1969; 11, (2): 29-35 (Author Communication Used).
Notes: EcoReference No.: 542
Chemical of Concern: 24D,24DXY,24DXYBEE,ACHY,ACL,AMTL,ATZ,BHAP,BOR,BORON,BRA,BSN881,CAP,CM PH,CPA,CuOX,DBN,DDT,DINO,DIOSSNa,DQTBr,DZ,DZM,FUR,MCPP1,MEM,MLH,MTAS,N aClO,NaDPA,NaDSS,NaPCP,PCLK,PL,PQT,PYZ,SZ,TBTO,TFN,TRL

2. Aziz, S. A. Toxicity of Certain Insecticide Standards Against the Southern Armyworm. MORTOP; 1973; 66, (1): 68-70.
Notes: EcoReference No.: 112632
Chemical of Concern: ADC,AND,AZ,CBF,CBL,CMPH,CPY,DDT,DDVP,DEM,DLD,DMT,DS,DZ,EN,EPRN,HCCH,HP T,MP,MVP,PPCP,PRN,PRT,PSM,TCF,TMP,TXP

3. Bacandritsos, N.; Papanastasiou, I.; Saitanis, C.; Na netti, A., and Roinioti, E. E fficacy of Repeated Trickle Applications of Oxalic Acid in Syrup for Varr oosis Control in Apis mellifera: Influence of Meteorological Conditions and Presence of Broo d. MOR,POPENV,MIXTURE; 2007; 148, (2):

174-178.
Notes: EcoReference No.: 151746 Chemical of Concern: CMPH,OXAC

4. Beatty, J. F.; Arnold, B. L.; Mc Gee, W. H.; Custer, E. W., and Daniels, J. W. The Effect of "Baymix" on Milk Production and Milk Quality. PHY,REP. Mi ssissippi Agricultural and Forestry Experiment Station//: ORAL; 1974; 37, (9): 8.
Notes: EcoReference No.: 157765
Chemical of Concern: CMPH

5. Beugnet, F. and Chardonnet, L. Tick Resistance to Pyrethroids in New Caledonia. MORENV; 1995; 56, (4):

325-338.
Notes: EcoReference No.: 115241 Chemical of Concern: CMPH,CPY,DM,DZ,ETN,FNTH,FNV,PTP

6. Bonzini, S.; Tremolada, P.; Bernardinelli, I.; Colo mbo, M., and Vighi, M. Predicting Pesticide Fate in the Hive (Part 1): Experimentally Determined Tau-Fluvalinate Residues in Bees, Honey and Wax. ACC. [Tremolada, P] Univ Milan, Dept Biol, I-2 0133 Milan, Italy//: ENV; 2011; 42, (3): 378-390.
Notes: EcoReference No.: 157830
Chemical of Concern: AMZ,CMPH,MLN,PMR,TAUF

7. Burley, L. M.; Fell, R. D., a nd Saacke, R. G. Survival of Honey B ee (Hymenoptera: Ap idae) Spermatozoa Incubated at Room Temperature from Drones E xposed to Miticides. POP,REP. lmburley@vt.edu//: ENV; 2008; 101, (4): 1081-1087.
Notes: EcoReference No.: 107876 Chemical of Concern: CMPH,TAUF,TML

8. Butler, P. A. Commercial Fishery Investigations. ACC,BEH,GRO,MOR,PHY,POP,SYSAQUA; 1964: 28 p. (Author Communication Used).
Notes: EcoReference No.: 646
Chemical of Concern:

### 108 24DXY,24DXYBEE,24DXYEE,AND,ANZ,AZ,CBL,CMPH,DCPA,DCTP,DDT,DDVP,DEM,DLD ,DMDP,DMT,DQT,DQTBr,DS,DU,EN,EPRN,EPTC,ES,ETN,FNT,FNTH,HCCH,HPT,MCB,MCP AD,MLN,MP,MRX,MVP,MXC,NTP,Naled,PAQT,P EB,PPCP,PPHD,PPX,PQT,PRN,PRT,PSM,TB F,TCF,TMP,TVP,TXP

9. Byford, R. L. ; Sparks, T. C.; Green, B.; Knox, J., and Wyatt, W. Organophosphorus Insecticides for the Control of Pyrethroid-Resistant Horn Flies (D iptera: Muscidae). MO R,POPENV,MIXTURE,TOP; 1988; 81, (6): 1562-1566.
Notes: EcoReference No.: 114522 Chemical of Concern: CMPH,CPY,DMT ,DZ,ETN,FNV,MLN,PIRM,PMR,TCF,TVP

10. Castella, J. and Estrada, A. Susceptibility of the Brown Dog Tick to Eight Acaricides, 1991. MORTOP; 1994; 19, 371-(4L).
Notes: EcoReference No.: 106250 Chemical of Concern: AMZ,CMPH,CYP,DM,DZ,PMR

11. Dorough, H. W.; Brady, U. E. Jr.; Timmerman, J. A., and Arthur, B. W. Residues in Tissues and Eggs of Poultry Receiving Co-Ral (Bayer 21/199) in th e Feed. ACC,REPORAL; 1961; 54, 97-100.
Notes: EcoReference No.: 103834
Chemical of Concern: CMPH

12. Drummond, R. O. Susceptibility of the Gulf Coast Tick (A cari: Ixodidae) to Acar icides. REPT OP; 1988; 81, (4): 1140-1142.
Notes: EcoReference No.: 114521 Chemical of Concern: AMZ,AsTO,CBL,CMPH,CPY,DZ,HCCH,MLN,PMR,PPCP,PSM,TVP,TXP

13. Drummond, R. O.; Ernst, S. E.; Trevino, J. L., and Graham, O. H. Insecticides fo r Control of the Cattle Tick and the Southern Cattle Tick on Cattle. POPTOP; 1968; 61, (2): 467-470.
Notes: EcoReference No.: 113241 Chemical of Concern: CBL,CMPH,CPY,DZ,ETN,FNTH,PPX,PSM

14. Drummond, R. O.; Whetstone, T. M.; Ernst, S. E., and Gladney, W. J. Control of Three-Host Ticks. Laboratory Tests of Systemic Insecticides in Feed of Cattle. MOR, PHY,POP,REPENV,ORAL; 1972; 65, (6): 1641-1644.
Notes: EcoReference No.: 114791 Chemical of Concern: CMPH,FNTH,PSM

15. Drummond, R. O.; Whet stone, T. M.; Shelley, B. K., and Barrett, C. C. Common Cattle Grub: Control with Animal Systemic Insecticides. MOR,POPENV; 1977; 70, (2): 176-178.
Notes: EcoReference No.: 113371 Chemical of Concern: CMPH,FNTH,MTPN,PSM,TCF

16. Gladney, W. J.; Ernst, S. E.; Dawkins, C. C.; Drummond, R. O., and Graham, O. H. Feeding Systemic Insecticides to Cattle for Control of the Tropical Horse Tick. GRO,MOR,POP,REPENV; 1972; 9, (5): 439-442.
Notes: EcoReference No.: 115592 Chemical of Concern: CMPH,FNTH,PSM

17. Gregorc, A. and Planinc, I. The Control of Varroa destructor Using Oxalic Acid. POPENV,MIXTURE; 2002; 163, (3): 306-310.
Notes: EcoReference No.: 151669 Chemical of Concern: CMPH,OXAC

18. Gregorc, A. and Poklukar, J. Rotenone and Oxa lic Acid as Alternative Acaricidal Treatments for Varroa destructor in Honeybee Colonies. MOR,POPENV,MIXTURE; 2003; 111, (4): 351-360.

### 109 Notes: EcoReference No.: 76055 Chemical of Concern: CMPH,OXAC,RTN

19. Hansen, M. F. and Zeakes, S. M. Efficacy of Ma retin and Baymix Against Nematodes of Calves. POPENV; 1969; 88, (1): 159-161.
Notes: EcoReference No.: 157729
Chemical of Concern: CMPH

20. Higes, M.; Meana, A.; Suarez, M., and Llorente, J. Negative Long-Term Effects on Bee Colonies Treated with Oxalic Acid Against Varroa jacobsoni Ou d. MOR,POP,REP. Dpto. Patologia Animal I (Sanidad Animal//: ENV; 1999; 30, (4): 289-292.
Notes: EcoReference No.: 151761 Chemical of Concern: CMPH,OXAC,TAUF

21. Hughes, P. B. and Devonshire, A. L. The Biochemical Basis of Resistance to Organophosphorus Insecticides in the Sheep Blowfly, Lucilia cuprina. ACC,MOR,PHYTOP; 1982; 18 , 289-297.
Notes: EcoReference No.: 71995 Chemical of Concern: CMPH,DZ,EPRN,PRN

22. Jones, K. H.; Sanderson, D. M., and Noakes, D. N. Acute Toxicity Data for Pesticides (1968). MORORAL,TOP; 1968; 7, (3): 135-143.
Notes: EcoReference No.: 70074
Chemical of Concern: 24DXY,ABT,ACL,ADC,AMTL,AMTR,AND,ASM,A TN,ATZ,AZ,BFL,BMC,BMN,BS,BTY,CBL, CCA,CHD,CMPH,CPP,CPY,CQTC,CTHM,Captan,Cu,CuFRA,DBN,DCB,DCNA,DCPA,DDD,DD T,DDVP,DEM,DINO,DLD,DMB,DMT,DOD,DPP,DQTBr,DS,DU,DZ,DZM,EDT,EN,EP,EPRN,E PTC,ES,ETN,FLAC,FMU,FNF,FNT,FNTH,Folpet,HCCH,HPT,LNR,MCB,MCPA,MCPB,MCPP1, MDT,MLH,MLN,MLT,MRX,MTM,MVP,MXC,Mane b,NPM,Naled,PCH,PCL,PCP,PEB,PHMD,P HSL,PMT,PPCP,PPHD,PPN,PPX,PPZ,PQT,PRN,PRO,PRT,PYN,PYZ,Pb,RTN,SFT,SID,SZ,TCF,T FN,THM,TRB,TRL,TXP,VNT,Zineb

23. Kaplanis, J. N.; Hopkins, D. E ., and Treiber, G. H. Dermal and Oral Treatments of Cattle with Phosphorus32-Labeled Co-Ral. ACCTOP; 1959; 7, (7): 483-486.
Notes: EcoReference No.: 157621
Chemical of Concern: CMPH

24. Kitchin, K. T.; Brown, J. L., and Kulkarni, A. P. Ornithine Decarboxylase In duction and DNA Damage as a Predictive Assay for Potential Carcinogenicity. BCM ,CELORAL; 1991; 369, 137-144 (Publ in part as 103823).
Notes: EcoReference No.: 103822 Chemical of Concern: CMPH,DDE

25. ---. Predicting Rodent Carcinogenicity of Halogenated Hydrocarbons by In Vivo Biochemical Parameters. BCM,CEL,MORORAL; 1993; 13, (4): 167-184.
Notes: EcoReference No.: 70486
Chemical of Concern: 13DPE,24D,24DXY,CF,CMPH,CQTC,CTC,DCB,DDE,DDT,DDVP,DPDP,DXN,EDB,EN,MRX,P BDE,PNB,TCDD,TXP

26. Kraus, B. and Berg, S. Effect of a Lactic Acid Treatment During Winter in Temperate Climate upon Varroa jacobsoni Oud. and the Bee (Apis mellifera L.) Colony. BEH,MOR,POP,REPENV,MIXTURE; 1994; 18, (8): 459-468.
Notes: EcoReference No.: 100418 Chemical of Concern: CMPH,LLA

### 110 27. Krueger, H. R.; Casida, J. E., and Niedermeier, R. P. Animal Metabolism of Insecticides. Bovine Metabolism of Organphosphorus Insecticides. Metabolism and Residues Associated with Dermal Application of Co-ral to Rats, a Goat, and a Cow. ACC,BCMTOP; 1959; 7, (3): 182-188.
Notes: EcoReference No.: 157620
Chemical of Concern: CMPH

28. Lammler, G. and Gruner, D. Chemotherapeutic St udies on Litomosoides carinii Infection of Mastomys natalensis. 6. The Filaricidal Activity of Organophosphorus Compounds. POPINJECT,ORAL; 1975; 26, (3): 359-369.
Notes: EcoReference No.: 104001 Chemical of Concern: CMPH,CPY,FNTH,PSM,TCF

29. Li, A. Y.; Pruett, J. H.; Davey, R. B., and George, J. E. Toxicological and Biochemical Characterization of Coumaphos Resistance in the San Roman Strain of Boophilus microplus (Acari: Ixodidae). BCM,MORTOP; 2005; 81, (3): 145-153.
Notes: EcoReference No.: 80229 Chemical of Concern: 3CE,CMPH,PPB

30. Mao, W.; Schuler, M. A., and Berenbaum, M. R. CYP9Q-Mediated Detoxification of Acaricides in the Honey Bee (Apis mellifera). CEL. Department of Entomology, University of Illinois, Urbana, IL 61801, USA.//: TOP; 2011; 108, (31): 12657-12662.
Notes: EcoReference No.: 156538 Chemical of Concern: BFT,CMPH,CYP,TAUF

31. Mayer, F. L. Jr. Acute Toxicity Handb ook of Chemicals to Estuarine Organisms. GRO,MOR,PHY,POPAQUA; 1987: 274 p.
Notes: EcoReference No.: 3947
Chemical of Concern: 24D,24DC,24DXY,24DXYBEE,ACD,ACL,ACP,ADC,ALSV,AMTR,AND,ANZ,ATM,ATZ,AZ,A gN,AsTO,BMC,BS,CAP,CBF,CBL ,CCA,CHD,CMPH,CPY,CST,CT N,CYP,Captan,CdCl,DBN,DC F,DCPA,DCTP,DDE,DDT,DDVP,DEM,DFZ,DLD,DMB,DMT,DQTBr,DS,DSMA,DU,DZ,EDT,E N,EP,EPRN,EPTC,ES,ETN,FBM,FMP,FNF,FN T,FNTH,HCB,HCCH,HCCP ,HMN,HPT,HgCl2,K2 Cr2O7,MCB,MDT,MLN,MLT,MP,MRX,MTAS,MV P,MXC,Maneb,NTP,NaHCT,NaLS,NaPCP,Na led,PCBZ,PCP,PEB,PHTH,PL,PMR,PMT,PPCP,PPHD,PPX,PQT,PRN,PRO,PRT,PSM,RTN,SFR,S Z,TBC,TBF,TBTO,TCF,TDC,TEG,TFN,T MP,TPTH,TRL,VNT,Zineb,Ziram,ZnS

32. McDougald, L. R.; White, R. G., and Hansen, M. F. Efficacy of Naphthalophos and Coumaphos Against Nematodes of Goats. POPENV; 1968; 29, (5): 1077-1079.
Notes: EcoReference No.: 157692
Chemical of Concern: CMPH

33. Miller, R. J.; Li, A. Y.; Tijerina, M.; Davey, R. B., and George, J. E. Differential Response to Diazinon and Coumaphos in a Strain of Boophilus microplus (A cari: Ixodidae) Collected in Mexico. BCM,MOR. robert.miller@ars.usda.gov//USDA-ARS, Cattle Fe ver Tick Research Laboratory, 22675 N. Moorefield Road, Edinburg, TX 78541////: EN V,MIXTURE; 2008; 45, (5): 905-911.
Notes: EcoReference No.: 119627 Chemical of Concern: CMPH,DZ,PPB

34. Mutinelli, F.; Baggio, A.; Capolongo, F.; Piro, R.; Pra ndin, L., and Biasion, L. A Scientific Note on Oxalic Acid by Topical Application for the Control of Varroosis. POPENV; 1997; 28, (6): 461-462.
Notes: EcoReference No.: 151767 Chemical of Concern: CMPH,OXAC

35. Nelson, D. L.; White, R. G.; Mozier, J. O., and A llen, A. D. Toxicity of Larger-than-Recommended Doses of Naphthalophos to Cattle, Sheep, and Goats. MOR,PHY,POPENV,M IXTURE,ORAL; 1970; 31, (1):

199-201.

### 111 Notes: EcoReference No.: 157873 Chemical of Concern: CMPH,FNTH,TCF

36. Neuhauser, H. and Krieger, K. Chemical Control of Varroa jacobsoni in Honey Bees from the AnimalHealth-Industry Aspect. ACC,MOR,POPENV; 1988; 46, 375-379.
Notes: EcoReference No.: 157770
Chemical of Concern: CMPH

37. O'Neill, D. K. and Hebden, S. P. Investigation of Sheep Dips. Part I - Mixtures of Lime Sulphur and Organic Phosphorus Compounds. ACC,MORTOP; 1966; 42, (6): 207-213.
Notes: EcoReference No.: 104226 Chemical of Concern: CMPH,CaPS,DZ

38. Pettis, J. S.; Collins, A. M.; Wilbanks, R., and Feld laufer, M. Survival and Func tion of Queens Reared in Beeswax Containing Coumaphos. CEL,GRO,POP,REPENV; 2006; 146, (4): 341-344.
Notes: EcoReference No.: 157886 Chemical of Concern: CMPH,FVL

39. Pfadt, R. E.; Lloyd, J. E., and Spackman, E. W. Power Dusting with Organophosphorus Insecticides to Control the Sheep Ked. POPENV; 1975; 68, (4): 468-470.
Notes: EcoReference No.: 108644 Chemical of Concern: CMPH,PSM

40. Rammell, C. G. and Bentley, G. R. Decay Ra tes of Organophosphate Residues in the Fleeces of Sheep Dipped for Flystrike Control. ACCTOP; 1989; 32, (2): 213-218.
Notes: EcoReference No.: 101119 Chemical of Concern: CMPH,DZ,PTP

41. Rammell, C. G.; Bentley, G. R., and Heath, A. C. G. Organophosphate Residues in the Wool of Sheep Dipped for Flystrike Control. ACCTOP; 1988; 31, (2): 151-154.
Notes: EcoReference No.: 101118 Chemical of Concern: CMPH,DZ,PTP

42. Rawlins, S. C. and Mansingh, A. Patterns of Resistance to Various Acaricides in Some Jamaican Populations of Boophilus microplus. MORUNK; 1978; 71, 956-960.
Notes: EcoReference No.: 72313
Chemical of Concern: CBL,CMPH,CPY,DCTP,DDT,DMT,DZ,FNT,HCCH,Naled,PIRM,PPCP,PPHD,PPX

43. Samuel, J. J.; Mani, K. B. S.; Cyrus, I., and Na tarajan, R. Studies on the Use of Synthetic Atropine Substitutes in Organo Phosphorus Pesticide Po isoning. MOR. Dep. Pharmacol.,Madras Vet. Coll.,Madras,India////: INJECT,MIXTURE; 1987; 16, (3): 135-136.
Notes: EcoReference No.: 157693
Chemical of Concern: CMPH

44. Schafer, E. W. Jr.; Brunton, R. B.; Lockyer, N. F., and De Grazio, J. W. Comparative Toxicity of Seventeen Pesticides to the Quelea, House Sparrow, and Re d-Winged Blackbird. MORORAL,TOP; 1973; 26,

154-157.
Notes: EcoReference No.: 38663 Chemical of Concern: 4AP,CBF,CMPH,DCTP,DEM,EPRN,FNTH,MCB,PRN

45. Shaw, R. D.; Cook, M., and Carson, R. E. Jr. Deve lopments in the Resistance Status of the Southern Cattle Tick to Organophosphorus and Carbamate Insecticides. MORTOP; 1968; 61, 1590-1594.
Notes: EcoReference No.: 72637
Chemical of Concern:

### 112 CBL,CMPH,CPY,DCTP,DZ,EPRN,ETN,HCCH,PPCP,PPHD,PRN,PYN,TXP

46. Sun, Y. P. Speed of Action of Insecticides and Its Correlation with Accumulation in Fat and Excretion in Milk. MORENV,TOP; 1971; 64, (3): 624-630.
Notes: EcoReference No.: 114907
Chemical of Concern: ADC,AND,CBL,CHD,CMPH,DDT,DDVP,DEM,DMT,DS,DZ,EN,EPRN,ES,ETN,FNTH,HCCH,H PT,MLN,MP,MPO,MVP,MXC,Naled,PCTP, PPCP,PPHD,PRN,PRT,PSM,TCF,TVP,TXP

47. Suphalucksana, W. and Ching, F. A. A Field Trial on the Efficacy of Iv ermectin, Albendazole and Coumaphos Against Parasites of Buffalo. POP,REPENV,INJECT,ORAL; 1991; 25, (2): 256-260.
Notes: EcoReference No.: 157629
Chemical of Concern: CMPH

48. Swierczewska, E.; Niemiec, J., and Noworyta-Glowacka, J. A Note on the Effect of Immunostimulation of Laying Hens on the Lysozyme Activity in Egg White. BCM. Department of Poultry Breeding,Warsaw Agricultu ral University,Warsaw, Pol////: INJECT,ORAL; 2003; 21, (1): 63-68.
Notes: EcoReference No.: 157623
Chemical of Concern: CMPH