### 1 of 74 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHI NGTON D.C., 20460

March 3 , 200 9 PC Code: 057901 DP Barcode: D356654 MEMORANDUM Subject: Registration Review : Problem Formulation for Ecological Risk,

Environmental Fate, Endangered S pecies , and Drinking Water Assessments for Trichlorfon To: Kylie Rothwell , Chemical Review Manager

Tracy Perry , Team Leader Reregistration Branch Special Review and Reregistration Division Office of Pesticide Programs From: Melissa Panger , Ph.D., B iologist

Kristina Garber, Biologist Environmental Risk Branch 4 Environmental Fate and Effects Division Office of Pesticide Programs Through: Elizabeth Behl, Chief

Environmental Risk Branch 4 Environmental Fate and Effects Division Office of Pesticide Programs The Environmental Fate and Effects Division (EFED) has completed the problem formulation (attached) for the ecological risk, environmental fate, endangered species, and drinking water assessments to be conducted as part of the Registration Review of the organophosphate insecticide , trichlorfon (PC Code 057901 ). Functioning as the first stage of the risk assessment process for registration review, this problem formulation provides an overview of what is currentl y known about the environmental fate and ecological ef

fects associated with trichlorfon and its degradates. It also describes the preliminary ecological risk hy pothesis and anal ys is plan for evaluating and characterizing risk to non
- target species and the environment in support o f the registration of trichlorfon
.

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# Problem Formulation for the Environmental Fate, Ecological Risk, Endangered Species , and Drinking Water Assessment s in Support of the Registration Review of

Trichlorfon

dimethyl2,2,2
- trichloro
- 1
- hydroxyethyl
-phosphonate (CAS 52
- 68
- 6 )



### Prepared by: Melissa Panger, Ph
. D . , Biologist Kristina Garber, Biologist Reviewed by: R. David Jones, Senior Agronomist Anita Pease, Senior Biologist Elizabeth Behl, Branch Chief U. S. Environmental Protection Agency Office of Pesticide Programs Environmental Fate and Effects Division Environmental Risk Branch IV 1200 P ennsylvania Ave., NW Mail Code 7507P Washington, DC 20460 

### March 3, 2009

### 3 of 74

Table of Contents 1. Purpose
................................ ................................ ................................ ........................... 4 2. Problem Formulation
................................ ................................ ................................ ..... 4 2.1. Nature of Regulatory Action
................................ ................................ .................... 4 2.2. Previous Risk Assessments
................................ ................................ ...................... 4 3. Stressor Source and Distribution
................................ ................................ .................... 5 3.1. Mechanism of Action
................................ ................................ ............................... 6 3.2. Overview of Pesticide Use and Usage
................................ ................................ ..... 6 3.3. Environmental Fate and Transport
................................ ................................ ........... 8 3.3.1. Degradation
................................ ................................ ................................ ..... 10 3.3.2. Transport
................................ ................................ ................................ ......... 10 3.3.3. Terrestrial Field Dissipation
................................ ................................ ........... 10 3.3.4. Bioaccumulation
................................ ................................ ............................. 11 4. Receptors
................................ ................................ ................................ ...................... 11 4.1. Effects to Aquatic Organisms
................................ ................................ ................ 12 4.2. Effects to Terrestrial Organisms
................................ ................................ ............ 15 4.3. Incident Database Review
................................ ................................ ...................... 17 4.4. Ecosystems Potentially at Risk
................................ ................................ .............. 20 5. Assessment Endpoints
................................ ................................ ................................ .. 20 6. Conceptual Model
................................ ................................ ................................ ........ 20 6.1. Risk Hy

pothesis
................................ ................................ ................................ .... 21 6.2. Conceptual Diagram
................................ ................................ ............................. 21 7. Analysis Plan
................................ ................................ ................................ ............... 23 7.1. Stressors of Concern
................................ ................................ ............................. 24 7.2. Measures of Exposure
................................ ................................ ........................... 24 7.3. Measures of Effect
................................ ................................ ................................ 26 7.4. Integration of Exposure and Effects
................................ ................................ ...... 27 7.5. Deterministic and Probabilistic Assessment Methods
................................ ........... 27 7.6. Endangered Species Assessments
................................ ................................ .......... 27 7.7. Drinking Water Assessment
................................ ................................ .................. 28 7.8. Preliminary Id entification of D ata Gaps
................................ ................................ 28 7.8.1. Fate
................................ ................................ ................................ .................. 28 7.8.2. Effects data for Trichlorfon
................................ ................................ ............ 32 7.8.3. Effects data for DDVP
................................ ................................ .................... 36 8. References
................................ ................................ ................................ .................... 39 Appendix A. Submitted Toxicity Data for Trichlorfon and DDVP.
................................ 46 Appendix B. The Risk Quotient Method and Levels of Concern
................................ ..... 63 Appendix C. Data Call
- In Tables
................................ ................................ ..................... 65

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1. Purpose The purpose of this problem formulation is to provide an understanding of what is known about the environmental fate and ecological effects of the registered uses of trichlorfon
. Trichlorfon is an organophosphate used as an insecticide on golf cours e turf, home lawns, ornamentals (flowers, trees and shrubs), and ponds (ornamental and bait fish and non
food aquatic plants )
. This document will provide a plan for anal yz ing data relevant to trichlorfon , and for conducting environmental fate, ecological risk, endangered species and drinking water assessments for registered trichlorfon uses. Additionally , this problem formulation is intended to identify data gaps, uncertainties , and potential assumptions used to address those uncertainties relative to characterizing the ecological risk associated with the registered uses of trichlorfon
. 2. Problem Formulation 2.1. Nature of Regulatory Action Under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), all pesticides distributed or sold in the United States generally must be registered b y EP A. In determining whether a pesticide can be registered in the U.S., EPA evaluates its safety to non - target species based on a wide range of environmental and health effects studies. In 1996, FIFRA was amended by the Food Quality Protection Act, and EPA was mandated to implement a new program for the periodic review of pesticides, i.e ., registration review (http://www.epa.gov/oppsrrd1/registration_review/). The registration review program is intended to ensure that, as the ability to assess risk evolves and as policies and practices change, all registered pesticides continue to meet the statutory standard of no unreasonable adverse effects to human health and the environment. Changes in science, public policy , and pesticide use practices will occur over time. Through the new registration review program, the Agency periodically reevaluates pesticides to make sure that as change occurs, produc ts in the marketplace can be used safel y. As part of the implement ation of the new Registration Review program pursuant to Section 3(g) of the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) , the Agency is beginning its evaluation of trichlorfo n to determine whether it continues to meet the FIFRA standard for registration. This problem formulation for the environmental fate, eco logical risk, endangered species , and drinking water assessment chapter in support of the registration review will be posted in the initial docket opening the public phase of the review process. 2.2. Previous Risk Assessments A national
- level ecological risk assessment was completed as part of the reregistration eligibility decision (RED) for trichlorfon in January 1997 (USEPA 1997 ). The Environmental Fate and Effects Division’s (EFED) science chapter for the RED, which incorporated new data, was revised in 2000 (USEPA 2000). An interim T olerance Reassessment and Risk Management Decision (TRED) for trichlorfon was conducted in

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2001 (USEPA 2001). The T RED was finalized in July 2006 after the cumulative human health risk assessment of the organophosphate (OP) class of pesticides was completed (USEPA 2006b ). A drinking water assessment was conducted for the TRED. In thi s assessment, it was concluded that drinking water risk estimates for surface and ground waters did not exceed levels of concern, except for children aged 1
- 6 obtaining drinking water from surface water sources (USEPA 2006 b ). The ecological risk assessm ent included in the trichlorfon RED was based on laboratory fate and ecotoxicological data submitted by the registrant in support of reregistration and from data in publicl y available literature, and incident reports of adverse effects on non target organism s assoc iated with the use of trichlorfon
. The previous ecological risk assessments considered the parent chemical onl y ( i.e. , the degradates of toxicological concern were not considered). The primary environmental concerns identified in the 1997 and 2000 environmental fate and ecological risk assessment s were acute and chronic risks to birds, mammals, fish, and aquatic invertebrates (USEPA 1997, 2000)
. Based on the results of the T RED, a number of mitigation measures were recommended to address risks to handlers and workers
. These risk mitigation measures included the following: prohibit broadcast treatment to golf course fairways (permit spot treatment to fairways); require a 7
- day application interval for application to turf and limit applications to no more than 3 per calendar year; require applicators to use a truck
- drawn spray rig for application to fish ponds over 1 acre ; and prohibit foliar applications to ornamentals (allow onl y direct soil spray to base of the plant). These mitigation measure s appear on some, but not all, of the current trichlorfon labels (see Section 3.2 ). An emergency exemption petition ( Section 18 ) ecological risk assessment for use of trichlorfon on ornamentals (in Kansas ) was also completed by EF ED ( 1996 ). The results o f the Section 18 assessment indicated that the proposed use of trichlorfon on ornamentals in Kansas would not result in risks to non
- target organisms. EPA reinitiated a formal consultation with the U. S. Fish and Wildlife Service (USFWS) in 1989 regarding trichlorfon impacts on endangered species. This consultation was on selected portions of five previous “cluster” biological opinions evaluating pesticides for certain crops (corn, cotton, soy beans, sorghum, wheat, barley , oats and rye), forestry use pe sticides, mosquito larvicides, and rangeland and pastureland pesticides. As a result, the USFWS issued a formal Biological Opinion (USFWS 1989)
. The opinion identi fied 79 aquatic species ( 6 amphibians, 41 fish, 6 aquatic invertebrates, and 25 mussels ) and one terrestrial species (a bird) that were classified as “ in jeopardy” from trichlorfon use
. 3. Stressor Source and Distribution Trichlorfon degrades to dichlorvos (DDVP), which is also a pesticide active ingredient (PC Code : 084001). DDVP is a registered pesticide used as an insecticide applied to greenhouses, mushroom houses, residential areas, and premise treatments in agricultural

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areas (e.g. barns and sheds) (USEPA 2006a). Unlike in previous ecological assessments conducted b y the Agency for trichlorfon, the major degradate DDVP will be considered in the ecological risk assessment conducted as part of the Registration Review process
. The assessment for registration review will estimate risk from exposure to trichlorfon, and its degradate DDVP by evaluating “total trichlorfon residues of concern” (trichlorfon plus DDVP). Although DDVP is a major degradate of trichlorfon, ecological and endangered species assessments for the trichlorfon registration review will not evaluate the usage or impact of DDVP as a primary active ingredient or as a degradate of other pesticide products. While DDVP may potentially be used simultaneously (for different purposes) within the same areas as trichlorfon, th e use of DDVP will not be addressed in the ecological and endangered species risk assessment s for the trichlorfon registration review
. However, the upcoming drinking water assessment for the trichlorfon registration review will consider all sources of DDVP, including direct applications of DDVP as a pesticide active ingredient, as well as uses of trichlorfon and naled (PC code: 034401), which both degrade to DDVP. 3.1. Mechanism of Action Trichlorfon , dimethyl 2,2,2
- trichloro
- 1
- hydroxyethyl
-phosphonate , is an insecticide belonging to the organophosphate class of pesticides. Organophosphate toxicity is based on the inhibition o f the enzy me acetyl cholinesterase, which cleaves the neurotransmitter acetyl choline. Inhibition of acetyl cholinesterase by organophosphate insecticides interferes with proper neurotransmiss ion in cholinergic neuro sy napses and neuromuscular junctions. The trichlorfon degradate DDVP has a similar mode of action. 3.2. Overview of Pesticide Use and Usage Trichlorfon was originally registered for use in the United States in 1955
. Currentl y, l abeled uses of trichlorfon include turfgrass (golf courses, recreational turf and residential turf), flowers, shrubs, trees, and ponds (those that contain bait and /or ornamental fish and/or non
- food aquatic plants )
. There are both commercial and residenti al uses. There are currentl y nine active S ection 3 and three Special Local Needs labels for products containing trichlorfon ( Table 1 )
. There are both granular and flowable uses
. According to the product label s , trichlorfon can be applied by aerial or ground equipment
. Currently there is only one label that allows for aerial applications (Dylox 80 SP, EPA reg. no.: 432
- 1326); all other labels limit application s to ground equipment. The maximum single application rate for trichlorfon is 8.15 lb a.i./acre
. None of the current labels specify a maximum number of applications allowed per year. Some labels specify a minimum 7
- day application interval and a maximum yearl y application rate of 24.5 lb a.i./acre ( Table 1 ). The remaining labels do not specify a minimum application interval or a maximum yearly application rate.

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At this time, no national level use data have been identified for trichlorfon. Pesticide use inform ation from the California Department of Pesticide Regulation (CDPR 2007), include county- level data for various trichlorfon uses from 2001
- 2003. Past uses of trichlorfon in California include: landscape maintenance, greenhouse, and water areas. Table 1 . Summary of Current Trichlorfon Labels. PRODUCT (% a.i.) / EPA REG. NO. USES APPL. METHOD (S) MAX. SINGLE

APPL. RATE MAX

YEARLY APPL. RATE/NO. OF APPL. APPL.

INTERVAL RESTRICTIONS
Dylox 80 Concentrate (80% )/432
- 12 89 For formul ation

into end use products N/A N/A N/A N/A Only for formulations into end
-use products on lawns, turf and recreation areas Dylox 80 SP (80% )/432
- 1326 Flowers, shrubs,

and trees and recreational lawns and turf Ground

Aerial 8.15 lb a.i./acre

Narcissus - 16 oz a.i./1,000 feet of row For Narcissus

– 1/year All other use
- Not specified Not specified
- Do not apply directly to water . Dylox 80 Turf and Ornamental (80% )/432
- 1289 Landscape

flowers, shrubs, trees, and landscape and recreational turf Gro und 8.15 lb a.i./acre Narcissus
- 16 oz a.i./1,000 feet of row (repeat treatments annually) 24.5 lb

a.i./acre No. of Applications Not Specified 7 days

Dylox 420 SL (37.3% )/432
- 1464 Landscape

flowers, shrubs, trees, and landscape and recreational turf; golf course and residential turf Ground 7 lb a.i./acre Narcissus – 13.8 oz a.i./1,000 feet of row 24.5 lb

a.i./acre For Narcissus

– 1 application/ year All other use

– N o. of applications n ot specified 7 days - Do not apply dire ctly to water.

- Do not apply when average wind speeds are greater than 15 mph

- Ap ply product using spray nozzles which produce a coarse droplet size

- Do not apply within 25 ft of lakes, reservoirs, rivers, permanent streams, marshes, natural ponds, or estuaries.

- Do not apply through any type of chemigation system

- Golf courses: broadcast use is limited to tees and greens; use on fairways is limited to spot treatments
Dylox 80 (80% )/ FL03001200 ( 432
- 1289 ) Commercially
operated aquaculture production systems containing ornamental fish or non - food aquatic plants Hand
- held

sprayer (systems less than 1 acre) Truck
- drawn sprayer (systems greater than 1 acre) 0.25 mg a.i./L Not specified 14
- days None

Dylox 80 (80% )/ AR98000300 ( 432
- 1289 ) Dylox 80 (80% )/ MO99000500 ( 432
- 1289 ) Commercially
operated ponds used f or bait fish and ornamental fish production aquatic plants Not specified

(limited to ground equipment on Federal label) 0.25 mg a.i./L Not specified Not specified (7
- day interval on Federal label) None

Dyl ox 6.2 Turfgrass Ground 8.10 lb a.i./acre 24.5 lb 7 days
- Do not apply directly

### 8 of 74

PRODUCT (% a.i.) / EPA REG. NO. USES APPL. METHOD (S) MAX. SINGLE

APPL. RATE MAX

YEARLY APPL. RATE/NO. OF APPL. APPL.

INTERVAL RESTRICTIONS
Granular (6.2% trichlorfon)/432
- 1308 (Bayer Environmental Science) Granular The Andersons Tee Time Insecticide with 6.2% Dylox (6.2% trichlorfon)/9198
- 110 (the Andersons Lawn Fertilizer Division) Granular a.i./acre Max. no. of applications not secified to water

- Golf courses: do not apply within 25 ft of lakes, reservoirs, rivers, permanent streams, marshes, natural ponds, or estuaries

- Not for use on turf being grown for sale

- Must be watered in after application to move product into root zone

- Golf courses: broadcast use is limited to tees and greens; use on fairways is limited to spot treatments Dylo x Grub Control (6.2% )/432
- 1394 Granular Lawns
Dylox 9.3% Insect Granules (9.3% )/72155
- 83 Granular Dylox Insect Granules (6.2% )/72155
- 33 Granular Lawns

(residential use only) Ground 8.1 0 lb a.i./acre Not specified Not specified
- Do not apply directly to water

- Do not apply near fish pools, ponds, streams or lakes

- Water thoroughly within 24 hrs after applying



### 3.3. Environmental Fate and Transport The chemical structures of trichlorfon and DDVP are depicted in Figure 1
. Registrant
submitted data defining th e physical, chemical, fate and transport characteristics associated with trichlorfon are summarized in Table 2 . As part of registration review, available fate studies for trichlorfon have been reevaluated by EPA . The fate and transport of trichlorfon in the environment is briefly discussed below.



## Cl Cl Cl O H P O C H 3 

## O O C H 3 

## O C H 3 

## O P O C H 3 

## O
Cl Cl Trichlorfon DDVP

### 9 of 74

Figure 1 . Structures of trichlorfon and DDVP.

Table 2 . General Che mical and Environmental Fate Properties of Trichlorfon and DDVP.

Chemical/Fate Property Trichlorfon Value (source) DDVP Value (source) Molecular Weight ( MW; g/mol) 257.4 (MRID 00152133 ) 22 1.0 (USEPA 2006a) Water Solubility ( Sol; mg/L; at 25 °C) 1. 36 x10 5 (MRID 00152 133) 0. 15 x10 5 (USEPA 2006a) Vapor Pressure (VP; torr; at 25 o C) 3.75 - 4.5 x10 - 6 (MRID 41535301, 41535302 ) 1. 2 x10 - 2 (@20 o C) (USEPA 2006a) Henry's Law Constant ( H; atm - m3 /mo l) 8 .20 - 9.84 x10 - 1 1 ( * ) 2.75 x10 - 6 (* ) Octanol
- water Partition Coefficient (Log KO W) 0. 30 (MRID 00162307 ) 1.58 (MRID 40798103 ) Octanol
- air Partition Coefficient (Log KOA) 9.7 ( ** ) 6.1 ( ** ) Organic carbon normalized partition coefficient ( L/kg; KOC ) 58.8* (EPI SUITE v. 3.20) 37 (MRID 41354105) Hydrolysis half lives (days) No data available pH 5: 11.6 pH 7: 5.2 pH 9: 0.88 (MRID 41723101) Aqueous photolysis half

- life (days) Stable (MRID 00148975) 10 (MRID 43326601) Soil Photolysis half

- life (days with 12 h light/12 h dark) No data available 0.65 (MRID 43642501) Aerobic Soil Metabolism half
- life (days) 6.4 (MRID 42243601) 0.42 (MRID 41723102) Anaerobic Soil Metabolism half
- life (days) 1.8 (MRID 42243601) 6.2 (MRID 43835701) Aerobic Aquatic Metabolism half
- life (days) No data available No data available Anaerobic Aquatic Metabolism half
- life (days) No data available 4.5 (MRIDs 40618201, 41354102, 42445101)
* Estimated according to: 

### ) 2002 ( * 760 * USEPA MW Sol VP H = **Estimated using Episuite v. 3.20.

### 10 of 74 3.3.1. Degradation No scientificall y valid studies are available to describe the degradation of trichlorfon by hydrol ys is
. Degradation of DDVP b y hydrol ys is is pH dependant . In a hydrolysis study, DDVP half

- lives decreased with increasing pH, with observed half
- lives of 11.6 days, 5.2 days, and 0.88 days, at pH 5, 7 and 9 , respectively (MRID 41723101). In a supplemental aqueous photolysis study , trichlorfon was stable to photolysis (MRID 00148975). Available aqueous and soil photolysis studies indicate that DDVP is more susceptible to photodegradation than trichlorfon, with half
- lives of 10 and 0.65 days, respectivel y (MRID s 43326601 and 43642501). In an acceptable aerobic soil metabolism study, trichlorfon had a half
- life of 6.4 days on a sandy loam soil. During this study, 3 major degradates were observed: dichloroaceti c acid (DCA) and 1
- hydroxy
- 2,2
- dichlorovinyl phosphate (HDCP) and carbon dioxide. DDVP was not detected as a degradate in this study (MRID 42243601). In an aerobic soil metabolism study, DDVP had a half
- life of 0.42 days (MRID 41723102). In an acceptable anaerobic soil metabolism study conducted with the same sandy loam soil, trichlorfon had a half
- life of 1.8 days. Major degradates observed during this study included: DCA, HDCP, carbon dioxide and gl yoxylic acid (GA). DDVP was observed as a minor degrad ate (MRID 42243601 ) . In an anaerobic soil metabolism study, DDVP had a half
- life of 6.2 days (MRID 43835701). 3.3.2. Transport No scientificall y valid studies are available to define the mobility of trichlorfon in soil. The estimated organic carbon partition coefficient (Koc 

### ) of 58.8 (EPIsuite, v.3.20) suggests that trichlorfon may be mobile in soil. Based on the results of an acceptable soil TLC study , DDVP is also mobile, with a Koc 

### of 37 L/kg (MRID 41354105). Consideration of the vapor pressure (3.75
- 4.5x10 - 6 

### torr; MRIDs 41535301, 41535302) and Henry ’s Law constant (8.20
- 9.84x10 - 11 

### atm - m 3 

### /mol) of trichlorfon indicates that it is unlikely to be transported significantly into the air through volatilization from the treatment site. In contrast, the vapor pressure (1.58x10 - 2 

### torr; EPI suite v.3.20) and Henry ’s Law constant (3.62x10 - 7 

### atm - m3 

### /mol) of DDVP are several orders of magnitude higher than those of trichlorfon , suggesting that DDVP may volatilize when it has been formed from trichlorfon
. In a laboratory volatility study , 84% of trichlorfon residues remained on the soil to which it was applied 14 days previously . Volatilized residues comprised 14% of the total applied, and were identified as carbon dioxide . Trichlorfon and DDVP were not identified as volatilized residues (MRID 40279302).

### 11 of 74 3.3.3. Terrestrial Field Dissipation Two supplemental terrestrial field dissipation studies are available where trichlorfon was applied to sandy loam soil and to turf in field lysimeters contained in Ontario and Missouri (MRIDs 47519201 and 45895501 , respectively). In the bare soil treatments of both studies, the majority of the applied residues were detected in the upper 0
- 6 inches of the test soil, with a half life of 3. 1 days in the Ontario test and 1.9 days in the Missouri test. Carbon dioxide was detected as a major degradate in the Ontario test and a minor degradate in the Missouri studies. In both studies, DCA was detected as a major degradate. DDVP was detected as a minor degradate in the Ontario study , but undetected in the Missouri study . The maximum residues detected in the leachate comprised <0.2% of the applied. 3.3.4. Bioaccumulation The octanol
- water partition coefficient s of trichlorfon (Log KOW 

### = 0.30; MRID 00162307) and DDVP (Estimated Lo g KOW 

### = 0. 60 ; EPI suite, v.3.20 ) indicate that trichlorfon and DDVP are not expected to bioaccumulate in aquatic ecos ys tems. The estimated L og octanol
- air partition coefficient s (Log KOA

### ) for trichlorfon and DDVP ( 9.7 and 6.1, respectivel y; EPI suite, v.3.20) in combination with their Lo g KOW 

### suggest that bio magnification of trichlorfon and DDVP in terrestrial food chains is unlikely (Kelly et al . 2007). In addition, bio magnification in terrestrial food chains may be limited by transformation of trichlorfon and DDVP to less toxic degradates
. 4. Receptors Consistent with the process described in the Overview Document (USEPA 2004), the risk assessment for trichlorfon relies on a surrogate species approach. T oxicological data generated from surrogate test species, which are intended to be representative of broad taxonomic groups, are used to extrapolate to potential effects on a variety o f species (receptors) inc luded under these taxonomic groupings. Because the trichlorfon degradate DDVP is also a registered pesticide (PC Code: 084001), data are available to define the toxicity of this degradate of concern to non
target organisms . To adequately capture the ri sk from trichlorfon use , the toxicity and potential exposure to non
- target animals to trichlorfon and its degradate DDVP will be considered
. The most sensitive endpoints from the available toxicity data for trichlorfon and DDVP will be used to quantify ri sk. A cute and chronic toxicity data from studies submitted by pesticide registrants along with the available open literature are used to evaluate the potential direct and indirect effects of trichlorfon to aquatic and terrestrial receptors. This includes toxicity on the technical grade active ingredient, degradates, and when available, formulated products ( e.g. , “Six
Pack” studies). The open literature studies are identified through EPA’s

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ECOTOX icology (ECOTOX) database (USEPA 2007 a ) , which employs a literature search engine for locating chemical toxicity data for aquatic life, terrestrial plants, and wildlife. The evaluation of both sources of data may also provide insight into the direct and indirect effects of trichlorfon and its degradate DDVP on bio tic communities from loss of species that are sensitive to the chemical and from changes in structure and functional characteristics of the affected communities. Open literature data from ECOTOX on trichlorfon are not currentl y av ailable; however, once re ceived, they will be evaluated for possible quantitative and/or qualitative inclusion in this risk assessment. A summary of the most sensitive data representing non - target organisms exposed to trichlorfon and DDVP in aquatic and terrestrial habitats i s provided in Sections 4 .1 and 4 .2, respectivel y. A summary of ecological incidents associated with trichlorfon and DDVP and a description of ecos ys tems potentiall y at risk are provided in Section s 4.3 and 4.4, respectivel y . 4 .1. Effects to A quatic O rgan isms Trichlorfon is classified as very highl y toxic to freshwater invertebrates, highl y toxic to freshwater fish, and practically nontoxic to estuarine/marine invertebrates (Eastern oysters) on an acute exposure basis. No acceptable acute data for trichl orfon are available for estuarine/marine fish. DDVP is classified as very highl y toxic to freshwater and estuarine/marine invertebrates , highl y toxic to freshwater fish , and moderatel y toxic to estuarine/marine fish on an acute exposure basis ( Table 3 )
. No acceptable aquatic plant toxicity data are currently available for trichlorfon or DDVP. Summaries of the most sensitive acute aquatic toxicity data available from registrant
- submitted studies for trichlorfon and DDVP are provi ded in Table 4 and in Table 5 , respectivel y . Additional information on the ecotoxicity data currently available for trichlorfon and DDVP are provided in APPENDIX A
. Table 3 . Clas sifications of acute toxicities of trichlorfon and DDVP to aquatic anim als.

TAXON Trichlorfon DDVP Freshwater Invertebrate Very highly toxic 1 Very highly toxic 1 Freshwater Fish Highly toxic 2 Highly toxic 2 Marine/Estuarine Invertebrate Practically non
- toxic 4 Very highly toxic 1 Marine/Estuarine Fish No data Moderately toxic 3 1 LC 50 <0.1 mg/L 2 LC 50 0.1
- 1.0 mg/L 3 LC 50 >1.0
- 10 mg/L 4 LC 50 >100 mg/L 

### For trichlorfon, chronic effects in aquatic animals include diminished survival (freshwater and estuarine/m arine invertebrates), reproduction (freshwater fish and estuarine/marine invertebrates), and growth (estuarine/marine invertebrate)
. No acute or chronic data are available for estuarine/marine fish for trichlorfon
. For DDVP, chronic effects in aquatic animals include diminished survival (freshwater and estuarine/marine fish), reproduction (freshwater invertebrates), and growth (freshwater and estuarine/marine invertebrates and estuarine/marine fish) . Summaries of the most

### 13 of 74

sensitive chronic aquatic toxicity data available from registrant
- submitted studies for trichlorfon and DDVP are provided in Table 4 and in Table 5 , respectivel y . Based on currently available data, DDVP appears to be more or equall y as toxic to aquatic animals when compared to trichlorfon on both an acute and chronic exposure basis.
Table 4 . Summary of Submitted Studies for Aquatic Organisms Exposed to T echnical Trichlorfon (M ost Sensitive Endpoints for Eac h Taxon). TAXON & SPECIES ENDPOINT MRID STUDY CLASS IFICATION COMMENTS Freshwater Invertebrate (Acute) Pteronarcella badia EC 50 (96
-hr) = 5.3 μg a.i. /L 40098001 Supplemental Adequate for RQ calculation; based on analysis of raw data, the slope is 5.2 (C .I.: 2.6

– 7.9) Freshwater Invertebrate (Chronic) Daphnia magna NOAEC =

0.0057 μg a.i./L 40452601 Acceptable LOAEC ( 0.0086 μg a.i./L) b ased on survival (all endpoints were affected in the study, the mo st sensitive was survival) Freshwater Fish (Acute) Rainbow trout ( Oncorhynchus mykiss ) LC 50 (96
-hr) = 158 μg a.i. /L 40098001 Supplemental Adequate for RQ calculation (reported as 156 in the M&E volume); no slope could be calculated Freshwater Fish (Chronic) Rainbow trout ( Oncorhynchus mykiss ) NOAEC = 11 0 μg a.i./L 425717
- 01 Acceptable Early life
- stage study; LOAEC ( 234 μg a.i./L) based on increased time to swim up Estuarine/ Marine Invertebrate (Acute) Eastern oyster ( Crassostrea virginica ) EC 50 >114 mg a.i./L 444992
- 01 Acceptable 96
- hr shell
- depos ition study; NOAEC = 83 mg a.i./L (based on 16% decrease in shell deposition) Estuarine/ Marine Invertebrate (Chronic) Mysid ( Mysidopsis bahia ) NOAEC = 3.1

μg a.i./L 444992
- 02 Acceptable Flow
- through, life
- cycle study; LOAEC ( 234 μg a.i./L) based on decreased number of neonates produced, decreased survival, d ec reased weight, and decreased length Estuarine/ Marine Fish No acute or chronic exposure data available Aquatic Non -Vascular and Vascular Plants No data available

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Table 5 . Summary of Submitted Studies for Aquatic Organisms Exposed to T echnical DDVP (Most Sensitive Endpoints for Each Taxon). TAXON & SPECIES ENDPOINT MRID STUDY CLASS IFICATION COMMENTS Freshwater Invertebrates (Acute) Water flea (

Daphnia pulex) EC 50 = 0.0 66 μg

a.i./L 40098001 Acceptable None

Freshwater Invertebrates (Chronic) Water flea (

Daphnia magna ) NOAEC = 0.0058

μg a.i./L 43890301 Acceptable LOAEC ( 0.0122 μg a.i./L) b ased on reduced egg production and growth (length and weight) Freshwater Fish (Ac ute) Cutthroat trout ( Oncorhynchus clarki) LC 50 = 170 μg

a.i./L 40098001 Acceptable None

Freshwater Fish (Chronic) Rainbow trout ( Oncorhynchus mykiss ) NOAEC = 5.2 μg

a.i./L 43788001 Acceptable LOAEC ( 10.1 μg a.i./L) b ased on decreased post
hatch larval survival Estuarine/ Marine Invertebrates (Acute) Mysid ( Americamysis bahia ) EC 50 = 19.1 μg

a.i./L 43571408 Acceptable None

Estuarine/ Marine Invertebrates (Chronic) Mysid ( Americamysis bahia ) NOAEC = 1.48 μg

a.i./L 43854301 Acceptable LOAEC ( 3.25 μg a .i./L) b ased on reduced grow

th (weight and length) Estuarine/ Marine Fish (Acute) Sheepshead minnow ( Cyprinodon variegates ) LC 50 = 7,350 μg

a.i./L 43571403 Acceptable None

Estuarine/ Marine Fish (Chronic) Sheepshead minnow ( Cyprinodon variegates ) NOAEC = 960 μg

a.i./L 43790401 Acceptable LOAEC ( 1840 μg a.i./L) b ased on reduced survival and length Aquatic Non Vascular and Vascular Plants No acceptable data available

### 15 of 74 4 .2. Effects to Terrestrial Organisms Trichlorfon is classified as moderatel y tox ic to mammals on an acute oral basis. Th ere are currentl y no accep table trichlorfon acute oral or sub
- acute dietary toxicity data for birds. DDVP is classified as very highl y toxic and moderatel y toxic to birds on an acute oral and sub
- acute dietary expo sure basis , respectively , and is classified as moderatel y toxic to mammals on an acute oral exposure basis. Trichlorfon is practically nontoxic and DDVP is highl y toxic to honey bees on an acute contact exposure basis ( Table 6 )
. Available data on the toxicity of trichlorfon and DDVP to terrestrial organisms are summarized in Table 7 and Table 8 , respectivel y. Table 6 . Classifications of Acute Toxicities of Trichlorfon and DDVP to Terrestr ial Animals.

TAXON Trichlorfon DDVP Mammals Moderately toxic 1 Moderately toxic 1 Birds No data Very highly toxic 2 Honey bees Practically non
- toxic 3 Highly toxic 4 1 LD 50 51
- 500 mg/kg 2 LD 50 <10 mg/kg 3 LD 50 >11 μg/bee 4 LD 50 <2 μg/bee 

### For trichlorfon, chronic effects in terrestrial animals include diminished reproduction (birds) and growth (mammals)
. For DDVP, chronic effects in terrestrial animals include diminished reproduction (birds and mammals) and growth (mammals). As with aquatic animals , DDVP appears to be more or equall y as toxic to terrestrial animals when compared to trichlorfon on both an acute and chronic exposure basis
. No terrestrial plant data are available for trichlorfon or DDVP.

### 16 of 74

Table 7 . Summary of Submitted Studies for Terrestrial Animals Exposed to T echnical Trichlorfon (M ost Sens itive Endpoints for Each Taxon). TAXON & SPECIES ENDPOINT MRID STUDY CLASS IFICATION COMMENTS Birds (Acute) No acceptable acute data available Birds (Sub ac ute) No acceptable acute data available Birds (Chronic) Bobwhite quail ( Colinus virginianus ) NOAEC = 9

mg/kg
- diet 43119501 Acceptable LOAEC ( 30 mg/kg
- diet) b ased on a decrease in hatchling survival (no eggshell thickness effects at any level

– highest = 85 ppm); there were 10 mortalties (1 control, 1 at the 8 ppm conc., and 8 at the 85 ppm conc.) Mam mals (Acute) Laboratory rat (Rattus norvegicus ) LD 50 = 136 mg

a.i./kg
-bw 00256446 Acceptable None

Mam mals (Chronic) Laboratory rat (Sprague
Dawley) NOAEC = 500

mg a.i./kg
- diet 42228301 Acceptable LOAEC ( 1,750 mg a.i./kg
- diet) b ased on reduced body weight and dilated renal pelvis in F 1 males and females Terrestrial Invertebrates Honey bee (

Apis mellifera ) LD 50 = 59.83 μg

a.i./bee (acute contact) ACC

000369 35 (Atkins et al ., 1975) Acceptable This study involved exposures of honey bees to trichlorfon in a formulated product. The slope for this study was 2.81.

### 17 of 74

Table 8 . Summary of Submitted Studies for Terrestrial Animals Exposed t o T echnical DDVP (M ost Sensitive Endpoints for Each Taxon). TAXON & SPECIES ENDPOINT MRID STUDY CLASS IFICATION COMMENTS Birds (Acute) Bobwhite quail ( Colinus virginianus ) LD 50 = 8.8 mg a.i./kg

bw 40818301 Acceptable None

Birds (Sub - acute) Ring
- necked pheasant (Phasianus colchicus ) LC 50 = 568 mg a.i./kg
diet 0022923 Acceptable None

Birds (Chronic) Mallard duck ( Anas platyrhynchos ) NOAEC = 5 mg a.i./kg
diet 44233401 Acceptable LOAEC (15 mg a.i./kg
diet) based on reduced eggshell thickness, eggs laid, and number of viable embryos Mam mals (Acute) Laboratory rat (Rattus norvegicus ) LD 50 = 56 mg a.i./kg
bw 0005467 Acceptable None
Mam mals (Chronic) Laboratory rat (Rattus norvegicus ) NOAEC = 20 mg

a.i./kg
- diet LOAEC = 8 0 mg a.i./kg
- diet 42483901 Acceptable Based on reduced fertility and pup weight

Terrestrial Invertebrates Honey bee (

Apis mellifera ) LD 50 = 0.5 μg a.i./bee

(contact) 00036935 Acceptable None



### 4.3. Incident Database Review A preliminary review on October 20, 2008, of the Ecological Incident Information System (EIIS , version 2.0 ) maintained b y the Agency ’s Office of Pesticide Programs (OPP) indicates a total of 4 reported ecological incidents associated with the use of trichlorfon and 5 associated with the use of DDVP ( Table 9 )
. All of the trichlorfon incidents occurred between 1973 and 2003. Three of the trichlorfon incidents involved aquatic animals ( i.e ., fish) and one involved terrestrial animals ( i.e ., birds) and all were associated with mortality of the affected animals
. The certainty categories for the four incidents ranged from possible (two incidents) to probable (two incidents), and two of the incidents involved registered uses while the remaining two involved misuses. Three of the incidents involved additional chemicals besides trichlorfon. Trichlorfon residues were reported in onl y one of the incident reports (see Table 9 ). The reported incidents for trichlorfon involved two uses that are no longer registered (alfalfa and agri cultural area) and two uses that are currently registered (lawn and golf course). The two currentl y registered uses had certainty categories of probable and possible.

### 18 of 74

All of the DDVP incidents occurred between 1973 and 1997. One of the DDVP incidents involved aquatic animals ( i.e ., fish) and four involved terrestrial animals ( i.e ., birds and mammals). All of the aquatic incidents involved mortality while the terrestrial incidents involved mortality and/or incapacitation with recovery
. The certainty c ategories for the five incidents ranged from possible (two incidents) to highl y probable [probable (two incidents); highl y probable (one incident)], and two of the incidents involved registered uses while the legality of use was undetermined for the remainin g three. Only one of the incidents involved additional chemicals besides DDVP. DDVP residues were reported in one of the incident reports and ChE inhibition (brain) was reported in another (see Table 9 ). The use site for one of the reported DDVP incidents was unknown. The remaining four incidents involved the following u se sites: industrial operation, agricultural area, building (inside), and apple
. Although incident reports for trichlorfon and DDVP have not been received by the Agency since 2003 and 1997, respectivel y, the absence of reported incidents should not be construed as the absence of incidents. Incident reports for non
- target organisms ty picall y provide information on mortality events only . Reports for other advers e effects, such as reduced growth or impaired reproduction, are rarel y received. EPA’s changes in the registrant reporting requirements for incidents in 1998 may also account for the reduced number of reported incidents. Registrants are now onl y required to submit detailed information on ‘major’ incidents. Minor incidents are generally reported aggregately and are not included in EIIS. In addition, there have been changes in state monitoring efforts due to lack of resources. However, the incident data that are available suggest that exposure pathways are complete and that exposure levels are sufficient to result in field
- observable effects.

### 19 of 74

Table 9 . Wildlife Incidents from the EIIS Associated with Trichlorfon or DDVP. CHEM . NAME INCIDENT

NO. TAXA

INVOLVED MAGNITUDE YEAR LOCATION USE LEGALITY OF USE CERTAINTY

CATEGORY RESIDUES OTHER CHEMICALS INVOLVED Endosulfan (0.3
- 0.59 ppb in affected water) B0000
- 224 Aquatic

animal ~1,000 fish

(carp, sunfish, and catfish) 1973 California Al falfa Misuse Possible 8.3

– 12 ppb in affected water Toxaphene

(3.5 ppb in affected water) I000223
- 001 Aquatic

animal ~100 dead

bluegill sunfish 1992 Indiana Lawn Registered use Probable No Isazofos (5.5 ppb in pond water) I008255
- 010 Terrestrial

animal 2 dead geese 1998 USA Agricultural area Registered

use Possible No None
Chlorithalonil Trichlorfon

I014538
- 013 Aquatic animal ~1 , 500 dead fish 2003 Indiana Golf course Misuse (rinsate released into pond) Possible No Propiconazole B0000
- 500
- 31 Aquatic

animal 379 dead fish 1973 Tennessee Industrial operation Undetermined Probable No None

B0000
- 500
- 21 Terrestrial

animal 8 dead mallard

ducks 1975 USA Agricultural area Registered

use Highly prob able No but there was brain ChE inhibition None

I002298
- 001 Terrestrial

animal 5 dead fox pups

(captive); 2 incapacitated fox pups (captive) 1995 USA Building (inside) Registered

use Possible No None

I003908
- 011 Terrestrial

animal 2 bluebird

chicks 1994 New York Apple Undetermined Probable No None
Naled (73 ppm in crop contents) DDVP

I019411
- 016 Terrestrial Animal 1 debilitated

red
- tailed hawk 1997 British Columbia, Canada Unknown Undetermined Possible 28 ppm in crop contents Fonofos

(14 ppm in crop contents)

### 20 of 74 4. 4 . Ecosystems Potentially at Risk The ecos ys tems at risk are often extensive in scope; therefore, it may not be possible to identify specific ecos ys tems during the development of a nation
- wide ecological risk assessm ent. However, in general terms, terrestrial ecos ys tems potentially at risk could include the treated field and immediately adjacent areas that may receive drift or runoff. Areas adjacent to the treated field could include cultivated fields, fencerows and hedgerows, meadows, fallow fields or grasslands, woodlands, riparian habitats and other uncultivated areas. Aquatic ecos ys tems potentially at risk (beyond the aquatic use sites) include water bodies adjacent to, or down stream from, the treated field and could include impounded bodies such as ponds, lakes and reservoirs, or flowing waterways such as streams or rivers. For uses in coastal areas, aquatic habitat also includes marine ecos ys tems, including estuaries. 5. Assessment Endpoints Assessment endpoints represent the actual environmental value that is to be protected, defined b y an ecological entity (species, community, or other entity) and its attribute or characteristics (USEPA 1998). For trichlorfon , the ecological entities may include the fo llowing: birds, mammals, terrestrial
-phase amphibians, reptiles, freshwater fish and invertebrates, aquatic
- phase amphibians, estuarine/marine fish and invertebrates, terrestrial plants, insects, and aquatic plants and algae. The attributes for each of these entities may include growth, reproduction, and survival. 6 . Conceptual Model For a pesticide to pose an ecological risk, it must reach ecological receptors in biologicall y s ignificant concentrations. An exposure pathway is the means by which a p esticide moves in the environment from a source to an ecological receptor. For an ecological pathway to be complete, it must have a source, a release mechanism, an environmental transport medium, a point of exposure for ecological receptors, and a feasibl e route of exposure. The conceptual model for trichlorfon provides a written description and visual representation of the predicted relationships among trichlorfon (and its degradate DDVP) , potential routes of exposure, and the predicted effects for the a ssessment endpoint. A conceptual model consists of two major components: risk hy pothesis and a conceptual diagram (USEPA 1998). The primary environmental concerns identified in the 1997 and 2000 environmental fate and ecological risk assessments for trichlorfon were acute and chronic risks to birds, mammals, fish, and aquatic invertebrates (USEPA 1997, 2000 ). However, these risks did

### 21 of 74

not include a consideration of the trichlorfon degradate DDVP. Based on available data, DDVP is more or equally as toxic to aquatic and terrestrial animals when compared to trichlorfon. Therefore, risks to non
- target species may be greater than previously assumed once DDVP is considered in the risk assessment process. Due to the number of data gaps that currentl y e xist for trichlorfon and DDVP (see Section 7.8 ), preliminary RQs for trichlorfon will not be calculated in this problem formulation. The Agency believes that calculating RQs for trichlorfon use at this time would not be informative due to the uncertainties associated with the current data gaps
. 6 .1. Risk Hypothesis A risk hy pothesis describes the predicted relationship between the stressor, exposure, and assessment endpoint response. For trichlorfon , the following ecological risk hy pothesis is being empl oyed for this ecological risk assessment: Based on the application methods, mode of action, fate and transport, and the sensitivity of non

- target aquatic and terrestrial species, trichlorfon residues of concern (including trichlorfon and its degradate DDV P) have the potential to reduce survival, reproduction, and/or growth in non

- target terrestrial and aquatic organisms when used in accordance with current trichlorfon label s . These non

target organisms include Federally listed threatened and endangered sp ecies as well as non

- listed species
. 6 .2. Conceptual Diagram The environmental fate properties of trichlorfon and DDVP indicate that runoff, spray drift, volatilization and direct spray represent potential transport mechanisms of trichlorfon and DDVP to aquatic and terrestrial habitats where non
- target organism s may be exposed . These transport mechanisms ( i.e ., sources) are depicted in the conceptual model s below (Figure 2 and Figure 3 ) along with the receptors of concern and the potential attribute changes in the receptors due to exposures of trichlorfon and DDVP
.

### 22 of 74

Figure 2 . Conceptual model for trichlorfon and DDVP effe cts on aquatic organisms. 

## Stressor Source

Receptors

Attribute Change Trichlorfon applied to use site Trichlorfon degrading to DDVP Spray drift

Fish/aquatic - phase amphibians Eggs Larvae Juveniles / Adults Individual organisms Reduced survival Reduced growth Reduced reproduction Food chain Reduction in algae Reduction in prey Habitat integrity Reduction in primary productivity Reduced cover Community change Surface water/ Sediment Runoff

Aquatic Animals Invertebrates Vertebrates 

## Exposure Media
Uptake/gills

or integument
In gestion In gestion Long range atmospheric transport Wet/dry deposition Soil Ground water

Uptake/gills or integument Aquatic Plants

Non
- vascular Vascular Uptake/cell, roots, leaves Riparian plant terrestrial exposure pathways see Figure 3

### 23 of 74

Figure 3 . Conceptual model for trichlorfon and DDVP effects on terrestrial organisms. 

### 7 . Analysis Plan In order to address the risk hypothesis, the potential for adverse e ffects on the environment is estimated. The use, environmental fate, and ecological effects of trichlorfon (and DDVP) are characterized and integrated to assess the risks using a ‘ total trichlorfon residues of concern ’ approach
. In this approach, estimated environmental concentrations (EECs) will be derived for combined trichlorfon and DDVP. Risk quotients (RQs) will be derived for the total residues of concern b y dividing EECs by the most sensitive endpoint from the available toxicity data for trichlorfo n and DDVP. This analysis plan will be revisited and may be revised depending upon the data available in the open literature and the information submitted by the public in response to the opening of the Registration Review docket. 

## Stressor Sour ce

Receptors

Attribute Change Trichlorfon applied to use site Trichlorfon degrading to DDVP Direct application Spray drift

Birds / Terrestrialphase amphibians / reptiles / mammals Terrestrial insects

Individual organisms Reduced survival Reduced growth Reduced reproduction Food chain Reduction in prey Habitat integrity Reduction in primary productivity Reduced cover Community change Terrestrial/riparian plants grasses/forbs, fruit, seeds (trees, shrubs) Runoff

Mammals 

## Exposure M edia Soil

In gestion In gestion
In gestion In gestion Dermal uptake/Ingestion Long range atmospheric transport Root uptake Wet/dry deposition

Birds / Amphibians In gestion

### 24 of 74 7 .1. Stressors of Concern The primary degradate of concern, DDVP, is considered to have attributes and effects similar to parent trichlorfon. Thus, DDVP degradate residue levels will be considered along with trichlorfon residue levels as ‘total trichlorfon residues of concern’ in this assessment, and model results (exposure estimates) will reflect the predicted fate of both trichlorfon and DDVP resulting from trichlorfon usage. In its ecological risk assessments, the Ag ency does not routinely include an evaluation of mixtures of active ingredients, either those mixtures of multiple active ingredients in product formulations or those in the applicator’s tank. In the case of the product formulations of active ingredients (that is, a registered product containing more than one active ingredient), each active ingredient is subject to an individual risk assessment for regulatory decision regarding the active ingredient on a particular use site. If effects data are available for a formulated product containing more than one active ingredient, the data may be used qualitatively or quantitatively in accordance with the Agency ’s Overview Document and the Services’ Evaluation Memorandum (USEPA 2004; USFWS/NMFS 2004). Available toxicity data for environmental mixtures of trichl orfon with other pesticides will be presented as part of the ecological risk assessment. It is expected that the toxic effect of trichlorfon , in combination with other pesticides used in the environment, is likely to be a function of many factors includin g but not necessaril y l imited to: (1) the exposed species, (2) the co
- contaminants in the mixture, (3) the ratio of trichlorfon and co - contaminant concentrations, (4) differences in the pattern and duration of exposure among contaminants, and (5) the differential effects of other phys ical/chemical characteristics of the receiving waters ( e.g. organic matter present in sediment and suspended water). Quantitatively predicting the combined effects of all these variables on mixture toxicity to any given taxa with confidence is beyond the capabilities of the available data and methodologies
. However, a qualitative discussion of implications of the available pesticide mixture effects data on the confidence of risk assessment conclusions will be addressed as part of the uncertainty anal ys is. 7 .2. Measures of Exposure In order to estimate risks of trichlorfon and DDVP exposures in aquatic and terrestrial environments, all exposure modeling and resulting risk conclusions will be made based on the maximum application rates for turfgrass, flowers, shrubs, trees, and ponds discussed in Section 3.2
. Measures of exposure are based on aquatic and terrestrial models that predict estimated environmental concentrations of trichlorfon residues of concern using maximum labe led application rates and methods , as well as any mitigation measures specificall y indicated on the label ( e.g. spray drift buffers) . The models used to predict aquatic EECs are the Pesticide Root Zone Model coupled with the Exposure Analysis Model S ys tem (PRZM/EXAMS). The model used to predict terrestrial EECs on food items is T
- REX. These models are parameterized using relevant reviewed registrant
- submitted environmental fate data.

### 25 of 74

PRZM (v3.12.2, May 2005) and EXAMS (v2.98.4.6, April 2005) are screening simulation models coupled with the input shell pe5.pl (Aug 2007) to generate dail y exposures and 1
- in
- 10 year EECs of trichlorfon residues of concern that may occur in surface water bodies adjacent to application sites receiving trichlorfon through runo ff and spray drift. PRZM simulates pesticide application, movement and transformation on an agricultural field and the resultant pesticide loadings to a receiving water body via runoff, erosion and spray drift. EXAMS simulates the fate of the pesticide and resulting concentrations in the water body . The standard scenario used for ecological pesticide assessments assumes application to a 10
- hectare agricultural field that drains into an adjacent 1
- hectare water body that is 2 meters deep (20,000 m 3 

### volum e) with no outlet. PRZM/EXAMS is used to estimate screening
- level exposure of aquatic organisms to trichlorfon residues of concern . The measure of exposure for aquatic species is the 1
- in
10 year return peak or rolling mean concentration. The 1
- in
- 10 ye ar peak is used for estimating acute exposures of direct effects to aquatic organisms. The 1
- in
- 10
- ye ar 60
- day mean is used for assessing chronic exposure to fish and aquatic
-phase amphibians
. The 1
- in
- 10
- ye ar 21
- day mean is used for assessing aquatic invertebrate chronic exposure. Exposure estimates for terrestrial animals assumed to be in the target area or in an area exposed to spray drift are derived using the T
- REX model (version 1.3.1, 12/07/2006). This model incorporates the Kenega nomograph, as modified by Fletcher et al. (1994), which is based on a large set of actual field residue data. The upper limit value s from the nomograph represent the 95 th 

### percentile of residue values from actual field measurements (Hoerger and Kenega , 1972). The Fletcher et al. (1994) modifications to the Kenega nomograph are based on measured field residues from 249 published research papers, including information on 118 species of plants, 121 pesticides, and 17 chemical classes. EECs for terrestri al plants inhabiting dry and wetland areas are derived using TerrPlant (version 1.2.2, 12/26/2006). This model uses estimates of pesticides in runoff and in spray drift to calculate EECs. EECs are based upon solubility, application rate and minimum incor

poration depth. Exposure estimates for birds (and, thus, terrestrial
- phase amphibians and reptiles), terrestrial invertebrates, and mammals assumed to be in the target area or in an area exposed to trichlorfon granules are derived using the T
- REX model (v ersion 1.3.1, 12/07/2006). T
- REX includes the capability to calculate the LD 50 

### ft - 2 

### risk index values. Conceptually , an LD 50 

### ft - 2 

### is the amount of a pesticide estimated to kill 50% of exposed animals in each square foot of applied area. Although a square foot does not have defined ecological relevance and any unit area could be used, risk presumably increases as the number of LD 50 

### s/ft2 

### increases. The LD 50

### /ft2 

### is used to estimate risk for granular formulations and row, banded, and in
- furrow applications. For additional information on the LD 50 

### ft - 2 

### risk index, please reference U.S. EPA (1992). The LD 50 

### ft - 2 

### is calculated using a toxicity value (adjusted LD 50 

### ) and the EEC (mg a.i. ft - 2 

### ) and is directly compared with the Agency's levels of concern (LOCs).

### 26 of 74

The AgDRIFT spray drift model (version 2.01; dated 5/24/2001) is used to assess exposures of terrestrial organisms to trichlorfon deposited on terrestrial habitats by spray drift. AgDRIFT will also be used to determine the appropriate PRZM/EXAMS parameter values for modeling the percent drift corresponding to the buffers indicated on the label and to model areas of effect for aquatic and terrestrial taxa
. Any available monitoring data obtained from the scientific literature or submitted studies will be us ed to characterize exposures of trichlorfon and DDVP to non
- target organisms. 7 .3. Measures of Effect Ecological effect s data are used as measures of direct and indirect effects to biological receptors. Data are obtained from registrant
- submitted studies or from literature studies identified by ECOTOX. The ECOTOX database (USEPA 2007 a ) provide s more ecological effects data in an attempt to bridge existing data gaps. ECOTOX is a source for locating single chemical toxicity data and potential chemical mixture toxicity data for aquatic life, terrestrial plants, and wildlife. ECOTOX was created and is maintained by the USEPA, Office of Research and Development, and the National Health and Environmental Effects Research Laboratory's Mid
- Continent Ecology Division. In formation on the potential effects of trichlorfon (and DDVP) on non - target animals is also collected from the Ecological Incident Information System (EIIS; USEPA 2007b ). The EIIS is a database containing adverse effect (typically mortality) reports on non target organisms where such effects have been associated with the use of pesticides. Where available, sublethal effects observed in both registrant
- submitted and open literature studies will be evaluated qualitatively . Such effects may include behavioral changes ( e.g. , lethargy and changes in coloration). Quantitative assessments of risks, though, are limited to those endpoints that can be directly linked to the Agency’s assessment endpoints of impaired survival, growth and reproduction. The assessment of risk for direct effects to non
- target organisms makes the assumption that toxicity of trichlorfon and DDVP to birds is similar to terrestrial
-phase amphibians and reptiles. The same assumption is made for fish and aquatic
-phase amphibians. The acute measures of effect used for animals in this assessment are the LD 50 

### , LC 50 

### and EC 50 

### . LD stands for "Lethal Dose", and LD 50 

### is the amount of a material, given all at once, that is estimated to cause the death of 50% of the test organisms. LC stands for “Lethal Concentration” and LC 50 

### is the concentration of a chemical that is estimated to kill 50% of the test organisms. EC stands for “Effective Concentration” and the EC 50 

### is the concentration of a chemical that is estimated to produce a specific effect in 50% of the test organisms. Endpoints for chronic measures of exposure for listed and non
- listed animals are the NOAEL/NOAEC and NOEC. NOAEL stands for “No Observed
Adverse
- Effect
- Level” and refers to the highest tes ted dose of a substance that has been reported to have no harmful (adverse) effects on test organisms. The NOAEC ( i.e. , “No
Observed
- Adverse
- Effect
- Concentration”) is the highest test concentration at which none

### 27 of 74

of the observed effects were statisticall y different from the control. The NOEC is the No
Observed
- Effects
- Concentration. For non - listed plants, only acute exposures are assessed ( i.e. , EC 25 

### for terrestrial plants and EC 50 

### for aquatic plants ) ; for listed plants either the NOAEC or EC 05 

### is used
. 7 .4 . Integration of Exposure and Effects Risk characterization is the integration of exposure and ecological effects characterization to determine the potential ecological risk from the registered use s of trichlorfon and the likelihood of direct and indirect effects to non
- target organisms in aquatic and terrestrial habitats. The exposure and toxicity effects data are integrated in order to evaluate the risks of adverse ecological effects on non
- target species. For the assessment of trichlorfon risks, the risk quotient (RQ) method is used to compare exposure and measured toxicity values. EECs are divided b y a cute and chronic toxicity values. The resulting RQs are then compared to the Agency ’s L evels of C oncern (LOCs) (USEPA 2004) (See Appendix B ) . Th ese criteria are used to indicate when trichlorfon ’s uses, as directed on the label s , have the potential to cause adverse direct or indirect effects to non
target organisms. In addition, incident data from the EIIS will be considered as part of the risk characterization. 7 .5 . Deterministic and Probabilistic Assessment Methods The quantitative assessment of risk will primarily depend on the deterministic point
estimate based approach described in the risk assessment. An effort will be made to further qualitativel y describe risk using probabilistic tools that the Agency has developed. These tools have been reviewed b y F IFRA Scientific Advisory Panels (http://www.epa.gov/scipoly /sap/index.htm) and have been deemed as appropriate means of refining assessments where deterministic approaches have identified risks. 7 . 6 . Endangered Species Assessments Consistent with the Agency ’s responsibility under the Endangered Species Act (ESA), the Agency will evaluate risks to Federally
- listed threatened and/or endangered (listed) species from registered uses of trichlorfon
. This assessment will be conducted in accordance with the Overview Document (USEPA 2004), provisions of the ESA, and the Servi ces’ Endangered Species Consultation Handbook (USFWS/NMFS, 1998)
. The assessment of effects associated with the registration of trichlorfon (and its degradate DDVP) is based on an action area. The action area is considered to be the area directl y or indirectly affected b y the federal action, as indicated by the exceedance of Agency Levels of Concern (LOCs) used to evaluate direct or indirect effects. The Agency ’s approach to defining the action area under the provisions of the Overview Document (USEPA 20 04) considers the results of the risk assessment process to establish boundaries for that action area with the understanding that exposures below the Agency’s defined LOCs constitute a no - effect threshold. For the purposes of this assessment, attention will be focused on the footprint of the action ( i.e ., the area where trichlorfon application occurs), plus all

### 28 of 74

areas where offsite transport ( i.e. , spray drift, runoff, etc. ) may result in potential exposure that exceeds the Agency ’s LOCs. Specific measure s of ecological effect that define the action area for listed species include any direct and indirect effects and/or potential modification of its critical habitat, including reduction in survival, growth, and reproduction as well as the full suite of subl ethal effects available in the effects literature. Therefore, the action area extends to a point where environmental exposures are below any measured lethal or sublethal effect threshold for any biological entity at the whole organism, organ, tissue, and cellular level of organization. In situations where it is not possible to determine the threshold for an observed effect, the action area is not spatially limited and is assumed to be the entire United States. 7.7 . Drinking Water Assessment A drinking water assessment will be conducted to support the human health risk assessment of trichlorfon in registration review . The drinking water assessment will incorporate model estimates of trichlorfon residues of concern (including DDVP and parent) in surface and ground waters. Concentrations of trichlorfon residues of concern in surface waters will be estimated using PRZM/EXAMS (see description above). Ground water estimates of concentrations of trichlorfon residues of concern will be estimated using the Screening Concentration in Ground Water (SCI
- GROW) model (v.2.3, July 2003). The drinking water assessment will also include a summary of available surface and ground water monitoring data. This drinking water assessment will consider all sources of DDVP, inc luding direct applications of DDVP as a pesticide active ingredient, as well as uses of trichlorfon and naled (PC code: 034401 ), which both degrade to DDVP. 7.8. Preliminary Identification of Data Gaps 7.8.1. Fate The environmental fate data requirements for trichlorfon are partiall y fulfilled with some data gaps still remaining (

### 29 of 74

Table 10 ). The data gaps are discussed below. Data Call
- In (DCI) tables for these data gaps are provided in Appendix C
.

### 30 of 74

Table 10 . Available environmental fate data for trichlorfon and rem aining data gaps. Guideline Description MRID Classification Data Gap? comm ents 835.2120 Hydrolysis 00148974 Invalid Yes 835.2240 Photodegradation in

water 00148975 Supplemental Yes

00148976 Invalid 835.2410 Photodegradation in

soil 40261401 1 Invalid Yes 835.2370 Photodegradation in air none Not applicable No 2 00098625 Invalid 835.41 00 Aerobic soil

metabolism 42243601 Acceptable No

00161359 Invalid 40279301 Invalid 835.4200 Anaerobic soil

metabolism 42243601 Acceptable No

835.4300 Aerobic Aquatic

Metabolism none Not applicable Yes 835.4400 Anaerob ic Aquatic

Metabolism none Not applicable Yes

00148977 Invalid 835.1230 835.1240 Leaching and

adsorption/ desorption 40261402 3 Invalid Yes
835.1410 Laboratory Volatility 40279302 Acceptable No 40279303 Inv alid 42322501 Invalid 45303501 Under review 45895501 Supplemental 835.6100 Terrestrial Field

Dissipation

47519201 Supplemental Yes

835.6200 Aquatic Field

Dissipation none Not applicable Yes 850.1730 Accumulation in Fish none Not applicable No 4 1 It appears that this study reports the same results as M RID 00157859. 2 Because trichlorfon is not expected to be volatile, data describing the photo degradation of trichlorfon in air are not necessary.

3 It appears that this study reports the same results as MRID 00157860.

4 Code of Federal Regulation s 40 (CFR40 2007) Part 158 Subpart D state that these data are not required w

hen the Log Kow of a chemical and its major degradates are <3. Based on a Log octanol
- water partition coefficient of 0.30 (MRID 00162307 ) for trichlorfon and 0.60 for DDVP , these data are not required for trichlorfon or DDVP . 

### Hydrolysis Acceptable data have not been provided to quantify the hydrolysis of trichlorfon. According to Code of Federal Regulations 40 (CFR40 2007) Part 158 Subpart N (data requirements for pesticides) , hydrol ys is data are required for pesticides with terrestrial or aquatic uses. Since trichlorfon uses are classified as terrestrial and aquatic, acceptable hydrolysis data for trichlorfon should be submitted to fulf ill OPPTS Guideline 835. 2120 . These data are used to estimate the degradation of trichlorfon in aquatic systems and ultimatel y to derive aquatic EECs using PRZM/EXAMS.

### 31 of 74

In the case that these data are unavailable at the time risk assessments are conducted, it will be assumed that trichlorfon is stable to hydrolysis
. Aqueous Photolysis Acceptable data have not been provided to quantify the aqueous photolysis of trichlorfon
. A ccording to Code of Federal Regulations 40 (CFR40 2007) Part 158 Subpart N (data requirements for pesticides) , aqueous photol ys is data are required for pesticides with terrestrial or aquatic use s. Although this represents a data gap, EFED does not recommend that the Agency request these data at this time because the available supplemental data are sufficient to characterize the photolysis of trichlorfon in the aquatic environment. Photolysis on soil Acceptable data have not been provided to quantify the photol ys is of trichlorfon on soil. According to Code of Federal Regulations 40 (CFR40 2007) Part 158 Subpart N (data requirements for pesticides), soil photolysis data are required for pesticides with terrestrial or aquatic uses. Since trichlorfon uses are classified as terrestrial and aquatic, acceptable soil photolysis data for trichlorfon should be submitted to fulfill OPPTS Guideline 835.2410. These data are used to characterize the degradation of trichlorfon in soil. In the case that these data are not submitted, it will be assumed that trichlorfon is stable to photolysis on soil
. Aerobic and Anaerobic Aquatic Metabolism Acceptable data have not been provided to quantify the metabolism of trichlorfon under aerobic and anaerobic aquatic conditions. According to Code of Federal Regulations 40 (CFR40 2007) Part 158 Subpart D (data requirements for pesticides) , aerobic and anaerobic aquatic metabolism data are required for pesticides with terre strial or aquatic uses. Since trichlorfon uses are classified as terrestrial and aquatic, a cceptable a erobic and anaerobic aquatic metabolism data for trichlorfon should be submitted to fulfill OPPTS Guidelines 835.4300 and 835.4400. These data are used to estimate the degradation of trichlorfon in aquatic systems and ultimately to derive aquatic EECs using PRZM/EXAMS. In the case that these data are unavailable at the time risk assessments are conducted, PRZM/EXAMS input parameter guidance default values will be employed to account for aerobic and anaerobic aquatic metabolism. Leaching and Adsorption/Desorption At this time, there are no acceptable studies to quantify the adsorption and desorption characteristics of trichlorfon in U.S. soils. EFED recomm ends that the Agency request the submission of an acceptable study under OPPTS Guideline 835.1230 to define Kd 

### and KOC 

### values of trichlorfon in U.S. soils. In the absence of these data, EFED will assume that there is no sorption of trichlorfon to soils or organic matter on the treatment site. In order to implement this in derivation of aquatic EECs, a KOC 

### value of 0 will be used to

### 32 of 74

parameterize PRZM/EXAMS. Input of a KOC 

### value >0 is expected to result in lower aquatic EECs. If acceptable data are provided , the uncertainties associated with this assumption will be reduced. Terrestrial Field Dissipation At this time, two supplemental studies are available to describe the dissipation of trichlorfon under terrestrial field conditions (MRIDs 45895501 and 4751 9201). An additional study has been submitted and is currently under review by EFED (MRID 45303501). At this time, no acceptable studies have been identified to fulfill the OPPTS Guideline 835.6100. Although this represents a data gap , EFED does not reco mmend that the Agency request these data at this time because the available supplemental data are sufficient to characterize the terrestrial field dissipation of trichlorfon
. Aquatic Field Dissipation At this time, no acceptable studies are available to describe the dissipation of trichlorfon under aquatic field conditions
. According to Code of Federal Regulations 40 (CFR40 2007) Part 158 Subpart D (data requirements for pesticides), aquatic field dissipation data are required for pesticides with aquati c uses. Since trichlorfon uses are classified as aquatic, aquatic field dissipation data for trichlorfon should be submitted to fulf ill OPPTS Guideline 835. 6200 . Environmental Chemistry Methods Independentl y validated anal ytical methods for residues in s oil and water (environmental chemistry methods) submitted by the registrant are used to evaluate anal yses described in submitted environmental fate and ecological effects studies. Submitted analytical methods are also used b y various Federal, State, Tribal, and local agencies to detect and monitor residues that are or are suspected to be in environmental compartments due to outdoor uses and accidental releases. Therefore, availability of these anal yt ical methods is necessary in order to protect human health and the environment from trichlorfon residues in the environment. Independent laboratory validations for submitted anal ytical methods are necessary to confirm the levels of detection and quantitation reported in registrant
-prepared validations. Use of trichlorfon may impact surface water quality due to runoff of rain water and drift of residues. Therefore, analy tical methods for are necessary for detecting trichlorfon residues in water and in soil or sediment. In the absence of independently validate d environmental chemistry methods, submitted environmental fate and ecological effects data may not be reviewable and entities outside the Agency may lack chemical
- specific methods for anal ys es in environmental compartments. Independently validated enviro nmental chemistry methods will be used to evaluate the submitted environmental fate and ecological effects data and will be made available to the public to support monitoring for trichlorfon residues
.

### 33 of 74 7.8.2. Effects data for Trichlorfon Although many sub missions have been made to provide data on the effects of trichlorfon to aquatic and terrestrial organisms, several data gaps still exist ( Table 11 

### - Table 13 ) . Data gaps include the following: avian acute oral toxicity, avian sub
- acute dietary toxicity , estuarine/marine fish acute toxicity, estuarine/marine invertebrate acute toxicity, estuarine/marine fish early
- life stage toxicity, and terrestrial and aquatic plant toxi city studies. The data gaps are discussed below. Table 11 . Available Ecological Effects Data for Terrestrial Anim als Exposed to Trichlorfon and Rem aining Data Gaps (Studies Classified as ‘ Invalid ’ are Not Included). Guideline Desc ription MRID/ Accession Classification Data Gap? Comments 850.2100 Avian oral toxicity None Not applicable Yes 1 850.2200 Avian dietary

toxicity None Not applicable Yes 2

43019501 Acceptable 850.2300 Avian reproduction 43019601 Accep table No 850.3020 Honeybee acute

contact toxicity 00036935 Acceptable No 1 An acute oral toxicity study using either a mallard duck or bobwhite quail AND passerines must be submitted to fulfill this data requirement. 2 Dietary toxicity studies using a waterfowl and an upland game species must be submitted to fulfill this data requirement.

### 34 of 74

Table 12 . Available Ecological Effects Data for Aquatic Animals Exposed to Trichlorfon and Rem aining Data Gaps (Studies Classified as ‘ Invalid ’ are Not In cluded). Guideline Description MRID/ Accession Classification Data Gap? comm ents 40098001 Supplemental 65495 Supplemental 850.1075 Freshwater fish

–

Ac ute toxicity 91766 Acceptable No

850.1075 Saltwater fish

–

Ac ute toxicity No ne Not applicable Yes 1 850.1010 Freshwater

invertebrates

– Ac ute toxicity 4009800 1 Supplemental No
850.1025 850.1035 850.1045 850.1055 Saltwater invertebrates

– Ac ute toxicity 444992 Acceptable Yes 1

850.1300 Freshwater

invertebrate

– life cycle test 40452601 Acceptable No
850.1350 Saltwater invertebrates

– life cycle test 444 99202 Acceptable No
850.1400 Freshwater fish

–

early life stage test 42571701 Acceptable No 850.1400 Saltwater fish

–

early life stage test No ne Not applicable Yes 2 850.1500 Fish

–

life cycle test No ne Not applicable No 1 The new Part 158 data requirements specify that acute toxicity data are required on one estuarine/marine mo llusk (guideline fulfilled), one estuarine/marine invertebrate (guideline not fulfilled) , and one estuarine/marine fish (guideline not fulfilled). 2 A saltwater fish early
- life stage test (850.1400) is required for trichlorfon because the acute toxicity value for saltwater fish is < 1 mg/L (using freshwater fish as a surrogate).

### 35 of 74

Table 13 . Available Ecological Effects Data for Plants Exposed to Trichlorfon and Remaining Data Gaps (Studies Classified as ‘Unacceptable’ are Not Included). Guideline Description MRID Classification Data Gap? comm ents 850.4100 Terrestrial Plant toxicity :

Tier I seedling emergence None Not applicable Yes 1
850.4225 Terrestrial Plant toxicity:

Tier 2 seedling emergence None Not applicable No 2
850.4150 Terrestrial Plant toxicity:

Tier I vegetative vigor None Not applicable Yes 1 850.4150 Terrestrial Plant toxicity:

Tier 2 vegetative vigor None Not applicable No 2 850.4400 Aquatic Plant Growth:

algae None Not applicable Yes 1 850.4400 Aquatic Plant Growth:

vascular plants None Not applicable Yes 1 1 The new Part 158 data requirements specify that toxicity data are required for terrestrial and aquatic plants. 2 Tier II studies will be required if tested terrestrial species exhibit a 25% or greater detrimental effect in the Tier I study.



### Avian Acute Oral Toxicity No acceptable avian acute oral toxicity data are currentl y available for trichlorfon. The new Part 158 data requirements [40 CFR Part 158 (CFR 40 2007) data requirements for conventional pesticides (72 FR 60934; USEPA 2007 c)] specify that acute avian oral toxicity data be submitted f or either a mallard duck or bobwhite quail AND a passerine species. Additionally , there is one possible ecological incident involving birds (geese) and the use of trichlorfon (I008255
- 010). There is also evidence to indicate that passerines are more sens itive to at least some OPs when compared to data from upland and game species. For example, dimethoate (an OP) is an order of magnitude more toxic to passerines than to upland/game species (USEPA 2008). Therefore, an avian oral toxicity test ( OPPTS Guide line 850.2100 ; http://www.epa.gov/opptsfrs/publications/OPPTS_Harmonized/850_Ecological_Effects_Test_Guidelines/ Drafts/850
- 2100.pdf



### ) is requ ired for either a mallard duck or bobwhite quail AND a passerine species , as specified in 40 CFR Part 158 (CFR40 200 7)
. Trichlorfon registrants will need to submit a passerine study protocol for review b y the Agency prior to initiation of the passerine study
. If oral acute toxicity data are not submitted for either mallard duck or bobwhite quail AND passerines, EFED will assume acute risk to birds in its assessment of trichlorfon
. Avian Sub

-

Acute Dietary Toxicity No acceptable avian sub
- acute dietary toxicity data are currently available for trichlorfon. The new Part 158 data requirements [40 CFR Part 158 (CFR 40 2007) data requirements for conventional pesticides (72 FR 60934; USEPA 2007 c)] specify that avian dietary

### 36 of 74

toxicity data be submitted for both a waterfowl and an upland game species. There are currentl y no acceptable acute oral or sub
- acute dietary toxicity data available for trichlorfon. However , there is one possible ecological incident involving birds (geese) and the use of trichlorfon (I008255
- 010) , indicating a potential risk to birds
. Therefore, an avian dietary toxicity test (OPPTS Guideline 850.2 2 00; http://www.epa.gov/opptsfrs/publications/OPPTS_Harmonized/850_Ecological_Effec ts_Test_Guidelines/ Drafts/850
- 22 00.pdf



### ) is required for both a waterfowl and an upland game species, as specified in 40 CFR Part 158 (CFR40 2007). If dietary toxicity data are not submitted for birds , EFED will assume acute risk to birds in its assessment of trichlorfon. E stua rine/Marine Fish Acute T oxicity Acute toxicity data are not available for estuarine and marine fish. In the absence of these data, an acute
- to - chro nic ratio (ACR) would norm ally be derived and the acute toxicity to estuarine and marine fish would be estimated based on the ACR for freshwater fish. However, there are currentl y no toxicity data (acute or chronic) for estuarine/marine fish, therefore, an ACR cannot be derived. In addition, three of the four reported ecological incidents associated with the use of trichlorfon have involved fish kills. Therefore, an estuarine/marine fish acute toxicity test (OPPTS Guideline 850.1075 ; http://www.epa.gov/o pptsfrs/publications/OPPTS_Harmonized/850_Ecological_Effects_Test_Guidelines/ Drafts/850
- 1075 .pdf



### ) is required in order to fulfill the data requirement. In the ab sence of acute toxicity data for estuarine and marin e fish, EFED will assume acute risk to non listed and listed species of estuarine and marine fish
. Estuarine/M

arine Invertebrate Acute T oxicity Although, acute toxicity data are available for an estuarine/marine mollusk, no acute data are currentl y av ailable for a non
- mollusk estuarine/marine invertebrate. The new Part 158 data requirements specify that acute toxicity data are required on one estuarine/marine mollusk (guideline fulfilled) and one estuarine/marine invertebrate (guideline not fulfilled)
. In the absence of these data, an acute
- to - chronic ratio (ACR) would norm ally be derived and the acute toxicity to estuarine/marine invertebrates would be estimated base d on the ACR for freshwater invertebrates
. However , the freshwater invertebrate data necessary for calculating the ACR are not av ailable. Chronic data are not available for the most acutel y s ensitive freshwater species ( Pteronarcella badia ). Therefore, an estuarine/marine acute toxicity test (OPPTS Guideline 850.1035 ; http://www.epa.gov/opptsfrs/publications/OPPTS_Harmonized/850_E cological_Effects_Test_Guidelines/ Drafts/850
- 1035 .pdf



### ) is required in order to fulfill the data requirement. In the ab sence of acute toxicity data for estuarine and marin e invertebrates, EFED will assume acute risk to non - listed and listed species of estuarine and marine invertebrates. Chronic Toxicity Studies with Estuarine and Marine Fish C hronic toxicity data are not available for estuarine and marine fish. In the absence of these data, an acute
- to - chronic ratio (ACR) would normally be derived and th e chronic toxicity to estuarine and marine fish would be estimated based on the ACR for freshwater fish. However , there are currentl y no toxicity data (acute or chronic) for estuarine/marine

### 37 of 74

fish, therefore, an ACR cannot be derived. S ome of the reported ecological incidents associated with the use of trichlorfon have involve d fish kills. Therefore, an estuarine/marine fish early life
- stage toxicity test ( OPPTS Guideline 850.1400 ; http://www.epa.gov/opptsfrs/publications/OPPTS_Harmonized/850_Ecological_E ffects_Test_Guidelines/ Drafts/850
- 1400.pdf



### ) is required in order to fulfill the data requirement. In the absence of chronic toxicity data for estuarine and marine fish, EFED will assume chronic risk to non - listed and listed species of estuarine and marine fish. Terrestrial Plant T

oxicity S tudies Toxicity data for terrestrial plants are not available for trichlorfon . Based on the 40 CFR Part 158 data requirements, Tier I level seedling emergence and vegetative vigor terrestrial plant data are required fo r all insecticides. Therefore, this data gap must be filled, and seedling emergence terrestrial plant data (OPPTS Guideline 850.41 00; http://www.epa.gov/opptsfrs/publications/OPPTS_Harmonized/850_Ecological_Effec ts_Test_Guidelines/ Drafts/850
- 41 00.pdf



### ) and vegetative vigor terrestrial plant data (OPPTS Guideline 850.415 0; http://www.epa.gov/opptsfrs/publications/OPPTS_Harmoniz ed/850_Ecological_Effects_Test_Guidelines/ Drafts/850
- 4150.pdf



### ) are required for trichlorfon at the Tier 1 level. In the absence of Tier I data, EFED will assume risk to non - listed and listed terrestrial plants. A quatic Plant Studies Toxicity data for vascular and non
- vascular aquatic plants are not available. Based on the 40 CFR Part 158 data requirements, Tier I level non
- target aquatic plant data are required for all insecticides. Therefore, this data gap must be filled, and non
- target aquatic plant data for algae and vascular plants ( OPPTS Guideline 850.4400 ; http://www.epa.gov/opptsfrs/publications/OPPTS_Harmonized/850_Ecological_Effects_Test_Guidelines/ Drafts/850
- 4400.pdf



### ) are required for trichlorfon at the Tier 1 level. In the absence of Tier I data, EFED will assume risk to non - listed and listed species of vascular and non
- vascular aquatic plants. 7.8. 3 . Effects data for DDVP Although much data has been provided on the effects of DDVP to aquatic and terrestrial organisms, several data gaps still exist ( Tables 14
- 16) . Data gaps include the following: avian acute oral toxicity , life
- cycle freshwater fish toxicity, and terrestrial and aquatic plant toxicity studies . The data gaps are discussed below.

### 38 of 74

Table 14 . Available Ecological Effects Data for Terrestrial Anim als Exposed to DDVP and Rem aining Data Gaps (Only Studies with the most Sensitive Toxicity Endpoints are Reported). Guideline Description MRID/ Accession Classification Data Gap? Comments 850.2100 Avian oral to xicity 40818301 Acceptable Yes 1 850.2200 Avian dietary

toxicity 0022923 Acceptable No 850.2300 Avian reproduction 44233401 Acceptable No 850.3020 Honeybee acute

contact toxicity 00036935 Acceptable No 1 The new Part 158 data requirements specify that acute avian oral toxicity data be submitted for either a mallard duck or bobw

hite quail AND a passerine species. An acute oral toxicity study using passerines must be submitted to fulfill this data requirement.
Table 15 . Availa ble Ecological Effects Data for Aquatic Animals Exposed to DDVP and Remaining Data Gaps (Only Studies with the most Sensitive Toxicity Endpoints are Reported). Guideline Description MRID/ Accession Classification Data Gap? comm ents 850.1075 Freshwater fis h

–

Ac ute toxicity 40098001 Acceptable No 850.1075 Saltwater fish

–

Ac ute toxicity 43571403 Acceptable No 850.1010 Freshwater

invertebrates

– Ac ute toxicity 40098001 Acceptable No

43571408 Acceptable No 850.1025 850.1035 850.1045 850.1055 Saltwater invertebrates

– Ac ute toxicity 43571404 Acceptable No 850.1300 Freshwater

invertebrate

– life cycle test 43890301 Acceptable No
850.1350 Saltwater invertebrates

– life cycle test 43854301 Acceptable No
850.1400 Freshwater fish

–

early life stage test 43788001 Acceptable No 850.1400 Saltwater fish

–

early life stage test 43790401 Acceptable No 850.1500 Fish

–

life cycle test None Not applicable No None

### 39 of 74

Table 16 . Available Ecological Effects Data for Plants Exposed to DDVP and Remaining Data Gaps (Only Studies with the most Sensitive Toxicity Endpoints are Reported). Guideline Description MRID Classification Data Gap? comm ents 850.4100 Terrestrial Plant toxicity:

Tier I seedling emergence None Not applicable Y es 1
850.4225 Terrestrial Plant toxicity:

Tier 2 seedling emergence None Not applicable No 2
850.4150 Terrestrial Plant toxicity:

Tier I vegetative vigor None Not applicable Yes 1 850.4150 Terrestrial Plant toxicity:

Tier 2 vegetative vigor None Not appli cable No 2 850.4400 Aquatic Plant Growth:

algae None Not applicable Yes 1 850.4400 Aquatic Plant Growth:

vascular plants None Not applicable Yes 1 1 The new Part 158 data requirements specify that toxicity data are required for terrestrial and aquatic plants 2 Tier II studies will be required if tested terrestrial species exhibit a 25% or greater detrimental effect in the Tier I study.



### Avian Acute Oral Toxicity Acceptable acute avian oral toxicity data were submitted for exposures of bob white quail to DDVP ; however, data are not available for passerines, which are required under the new 40 CFR Part 158 (CFR 40 2007) data requirements for conventional pesticides (72 FR 60934; USEPA 2007 c). The new Part 158 data requirements specify that acute avian oral toxicity data be submitted for either a mallard duck or bobwhite quail AND a passerine species. Based on the results of previous ecological risk assessments for DDVP , risks are expected for non
- listed and listed birds due to acute exposure s to DDVP from the use of trichlorfon
. Additionally , three of the five ecological incidents associated with DDVP involved birds , including one involving passerines (bluebirds; I003908
- 011). Therefore, an avian oral toxicity test (OPPTS Guideline 850.2100 ; http://www.epa.gov/opptsfrs/publications/OPPTS_Harmonized/850_Ecological_Effects_Test_Guidelines/ Drafts/850
- 2100.pdf



### ) is required for passerine birds, as specified in 40 CFR Part 158 (CFR40 2007). Trichlorfan registrants will need to submit a passerine study protocol for review by the Agency prior to initiation of this study . If oral acute toxicity data are not submitted for passerines, EFED will assume acute risk for passerine species. Terrestrial Plant Toxicity Studies Toxicity data for terrestrial plants are not available for DDVP . Based on the 40 CFR Part 158 data requirements, Tier I level seedling emergence and vegetative vigor terrestrial plant data are required for all insecticides. Therefore, this data gap must be filled, and seedling emergence terrestrial plant data (OPPTS Guideline 850.41 00; http://www.epa.gov/opptsfrs/publications/OPPTS_Harmonized/850_Ecological_Effec ts_Test_Guidelines/

### 40 of 74

Drafts/850
- 41 00.pdf



### ) and vegetative vigor terrestrial plant data (OPPTS Guideline 850.415 0; http://www.epa.gov/opptsfrs/publications/OPPTS_Harmonized/850_Ecological_Effects_Test_Guidelines/ Drafts/850
- 4150.pdf



### ) are required for DDVP at the Tier 1 level. In the absence of Tier I data, EFED will assume risk to terrestrial plants. Aquatic Plant Studies Toxicity data for vascular and non
- vascular aquatic plants are not available. Based on the 40 CFR Part 158 data requirements, T ier I level non
- target aquatic plant data are required for all insecticides. Therefore, this data gap must be filled, and non
- target aquatic plant data for algae and vascular plants (OPPTS Guideline 850.4400; http://www.epa.gov/opptsfrs/publications/OPPTS _Harmonized/850_Ecological_Effects_Test_Guidelines/ Drafts/850
- 4400.pdf



### ) are required for trichlorfon at the Tier 1 level. In the absence of Tier I data, EFED will assume risk to both vascular and non
- vascular aquatic plants. 8. References CDPR. 2007. a . Pesticide Use Reporting. California Environmental Protection Agency, Department of Pesticide Regulation. Available online at: http://www.cdpr.ca.gov/docs/sw/surfcont.htm
. (Accessed 5/31/2007). CFR 40. 2007. Code of Federal Regulations 40 Parts 150 to 189. Protection of the Environment . U.S. Government Printing Office. 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. Environ. Tox. Chem. 13:1383
- 1391. Hoerger, F. and E. E. Kenaga, 1972. Pesticide 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., Stuttgart, West Germany, pp. 9
- 28. U.S. Environmental Protection Agency (USEPA). 1996. Emergency Exemption for use of Trichlorfon on Ornamentals in Kansas (PC Code# 057901; DP Barcode D229695; ID# 96KS0006; Case# 287853; Sponsor: Kansas Dept. of Agriculture). USEPA. 1997. Reregistration Eligibility Decision (RED): Trichlorfon. U.S. Environmental Protection Agency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, Washington DC . January 1997
. USEPA . 1998. Guidelines for Ecological Risk Assessment. Risk Assessment Forum, Office of Research and Development, Washington, D.C. EPA/630/R
- 95/002F. April 1998. http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=30759 USEPA. 2000
. Reregistration Eligibility Science Chapter for Tri chlorfon: Fate and Environmental Risk Assessments. U.S. Environmental Protection Agency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, Washington DC . April 2000
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### 41 of 74

USEPA. 2001. Report on FQPA Tolerance Reassessment Progress and Interim Risk Management Decision (TRED) for Trichlorfon. U.S. Environmental Protection Agency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, Washington DC . September 2001
. USEPA. 2002. Guidance for Sele cting Input Parameters in Modeling the Environmental Fate and Transport of Pesticides, Version II. US Environmental Protection Agency, Washington DC. Online at: http://www.epa.gov/oppefed1/models water/input_guidance2_28_02.htm. USEPA. 2004. Overview of the Ecological Risk Assessment Process in the Office of Pesticide Programs. U.S. Environmental Protection Agency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, Washington DC. January 23, 2004. USEPA. 2006a
. Interim reregistration Eligibility Decision for Dichlorvos (DDVP). U.S. Environmental Protection Agency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, Washington DC . June 2006
. USEPA. 2006 b . Finalization of Interim Reregi stration Eligibility Decisions (IREDs) and Interim Tolerance Reassessment and Risk Management Decisions (TREDs) for the Organophosphate Pesticides, and Completion of Tolerance Reassessment and Reregistration Eligibility Process for Organophosphate Pesticid es. Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, Washington DC . July 3 1, 2006
. USEPA. 2007 a . ECOTOXicology Database. Office of Research and Development National Health and Environmental Effects Research Laboratory ’s (NHEERL’s) Mid
- Continent Ecology Division (MED). http://cfpub.epa.gov/ecotox/ USEPA. 2007b . Ecological Incident Information System. http://www.epa.gov/espp/consultation/ecorisk
overview.pdf USEPA. 2007c . 40 CFR Part 158. Pesticides; Data Requirements for Conventional Chemicals: Final Rule. 72 FR 60934. October 26, 2007. USEPA. 2008. Risks of dimethoate use to the federally
- l isted California red
- legged frog (Rana aurora draytonii). U.S. Environmental Protection Agency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, Environmental Fate and Eff ects Division. January 31, 2008
. U.S. Fish and Wildlife Service (USFWS) . 1989. U.S. Fish and Wildlife Service Biological Opinion on Selected Pesticides: Dated June 14, 1989; Revised September 14, 1989. USFWS and National Marine Fisheries Service (NMFS). 1998. Endangered Species Consultation Handbook: Procedures for Conducting Consultation and Conference Activities Under Section 7 of the Endangered Species Act. Final Draft. March 1998
. SUBMITTED FATE STUDIES: MRID: 000 98625 Khasawinah, A.M. (1972) The Fate of ^(R)IDylox in Soil: Report N o. 32365. (Unpublished study received May 20, 1977 under 3125
- 210; submitted by Mobay Chemical Corp., Kansas City, Mo.; CDL:230752
- S) MRID: 00 148974 Pither, K.; Johnson, T. (1985) Hydrolysis of Dylox in Sterile Aqueous Buffer Solutions: Report No. 90113. Unpublished study prepared by Mobay Chemical Corporation. 16 p.

### 42 of 74

MRID: 00 148975 Pither, K.; Johnson, T. (1985) Photodecomposition of Dylox in Aqueous Solution: Report No. 90155. Unpublished study prepared by Mobay Chemical Corporation. 15 p. MRID: 00 14 8976 Pither, K.; Johnson, T. (1985) Photodecomposition of Dylox on a Soil Surface: Report No.90153. Unpublished study prepared by Mobay Chemical Corporation. 17 p. MRID: 00 148977 Lee, S.; Hanna, L. (1985) Leaching Characteristics of Aged Dylox Soil Resi dues: Report No. 90154. Unpublished study prepared by Mobay Chemical Corporation. 13 p. MRID: 00 152133 Mobay Chemical Corp. (1985) Product Chemistry of Trichlorfon Technical: Dylox Technical. Unpublished compilation. 22 p. MRID: 00 161359 Minor, R.; Fre eseman, P. (1986) [Carbon 14] Dylox Anaerobic Soil Metabolism: 93088.Unpublished study prepared by Mobay Corp. 29 p. MRID: 00 162307 Technology Services Group (1986) [Product Chemistry Data for Technical Trichlorfon]. Unpublished compilation. 101 p. MRID : 40261401 Pither, K. (1987) Photodecomposition of Dylox on a Soil Surface: Report No. 91700. Unpublished study prepared by Mobay Corp. 35 p. MRID: 40279301 Minor, R.; Freeseman, P.; Pfankuche, L. (1987) The Fate of Dylox under Anaerobic Soil Conditions : Mobay Project ID: 94596. Un
- published study prepared by Mobay Corp. 58 p. MRID: 40279302 Ridlen, R. (1987) Volatility of Dylox and Its Degradates from Soil: Report No. 94598.Unpublished study prepared by Mobay Corp. 40 p. MRID: 40279303 Loeffler, W. (1987) Dissipation of Dylox in Field Soil: Laboratory Project ID: DL
- 8300
- 86: Dylox Objective No. 8300. Unpublished study prepared by Chemonics Laboratories. 62 p. MRID: 40618201 Pack, D.; Fry, C. (1988) Anaerobic Aquatic Metabolism of (Ethyl
- 1
- ?Carbon 1 4| Naled): Revised Report: Laboratory Project ID MEF
- 0012/8809272. Unpublished study prepared by Chevron Chemical Co. 52 p. MRID: 41354102 Pack, D.; Fry, C. (1988) Supplement to "Anaerobic Aquatic Metabo
- lism of (Ethyl
- 1
- [Carbon
- 14]) NALED": Lab Projec t Number: MEF/ 0012/8716931. Unpublished study prepared by Chevron Chemical Co. 3 p. MRID : 41354105 Pack, D. (1987) Supplement to "Estimation of Soil Adsorption Coefficient of NALED from TLC Data": Lab Project Number: MEF0051/8716396A. Unpublished study p repared by Chevron Chemical Co. 4 p. MRID: 41535301 Sewekow, ?. (1988) Vapor Pressure of Trichlorfon Pure Active Ingredient: Lab Project Number: 100 128: 87267. Unpublished study prepared by Mobay Corp. 11 p.

### 43 of 74

MRID: 41535302 Weber, ?. (1987) Vapor Pressure of Trichorfon Pure Active Ingredient: Lab Project Number: 681 538: 94641. Unpublished study prepared by Corp., and Bayer Ag. 7 p. MRID: 41723101 Vithala, R. (1990) DDVP
-- Hydrolysis of ?C 14| DDVP in Aqueous Solu
- tions Buffered at pH 5, 7, and 9: Lab P roject Number: 006/006/ 001/89. Unpublished study prepared by Univ. of Pittsburgh, Center for Hazardous Materials Research. 141 p. MRID: 41723102 Vithala, R. (1990) DDVP
-- Ae robic Soil Metabolism of ?C 14| DDVP: Lab Project Number: 006/006/004/89. Unpubli shed study prepared by Univ. of Pittsburgh, Center for Hazardous Materials Research. 7 p. MRID: 42243601 Ridlen, R.; Pfankuche, L. (1989) Metabolism of ?1
- carbon 14| Trichlorfon in Soil: LabProject Number: 99640. Unpublished study prepared by Mobay Corp. 66 p. MRID: 42322501 Grace, T.; Cain, K. (1990) Dissipation of Trichlorfon in California Soils: Lab ProjectNumber: DL830089R01: 100160: ML022101. Unpublished study prepared by Plant Sciences, Inc.; NET Atlantic, Inc.; Pace Labs. 3801 p. MRID: 42445101 Pack, D.; Fry, C. (1988) Naled
-- Anaerobic Aquatic Metabolism of ?Ethyl
- 1
- carbon 14| Naled
-- Reivsed Report: Supplemental: Lab Project Number: MEF
- 0012/8809272. Unpublished study prepared by Chevron Chemical Co. 11 p. MRID: 43326601 Mobley, S. (1994) Aqueou s Photolysis of (carbon 14) DDVP (Dichlorvos) in Artificial Light: Lab Project Number: 838: 1611. Unpublished study prepared by PTRL East, Inc. 95 p. MRID: 43642501 Misra, B. (1995) Photodegradation of (Carbon
- 14)
- DDVP (Dichlorvos) on Sandy Loam Soil Und er Artificial Sunlight Irradiation: Final Report: Lab Project Number: ME 9400184. Unpublished study prepared by Pittsburgh Environmental Research Lab, Inc. 79 p. MRID: 43835701 Mobley, S. (1995) Anaerobic Soil Metabolism of (carbon 14)DDVP (Dichlorvos): Lab Project Number: 882: 1847. Unpublished study prepared by PTRL East, Inc. 82 p. 45303501 Kasper, A.; Shadrick, B. (1993) Abbreviated Soil Dissipation of (carbon 14) Trichlorfon on California Soils: Lab Project Number: 92157
- B: DL042102: 105157. Unpubl ished study prepared by Pan
- Agricultural Laboratories, Inc. 102 p. MRID: 45895501 Damon, A.; Lenz, M. (2003) Terrestrial Field Dissipation of (Carbon 14)
- TrichlorfonUsing Field Lysimeters
-- Missouri: Lab Project Number: 110960: 45525: DL022101.Unpublished study prepared by Analytical Bio
- Chemistry and Bayer CropScience. 82 p. MRID: 47519201 Damon, A.; Lenz, M. (2002) Terrestrial Field Dissipation of 14 C
- Trichlorfon Using Field Lysimeters
- Ontario. Project Number: 111049. Unpublished study prepared by ABC Laboratories, Inc. and Bayer Corporation. 123 p.

### 44 of 74

SUBMITTED EFFECTS STUDIES: ECOTOX Reference Number: 000347
- 69 Hill, E.F., et al. 1975. Lethal Dietary Toxicities of Environmental Pollutants to Birds. U.S. Department of the Interior, Fish and Wildli fe Service, Special Scientific Report

– Wildlife No. 191. Washington, D.C. MRID: 43019601 Pedersen, C.; Thompson, S.; Lesar, C. (1993) Effects of DYLOX Technical on Mallard Duck Reproduction: Lab Project Number: 101/006/08: DL740801: 106226. Unpublishe d study prepared by Bio
Life Associates, Ltd. and Miles Inc. Agricultural Division. 261 p. MRID: 43119501 Pedersen, C.; Thompson, S. (1994) Effect of DYLOX Technical on Bobwhite Quail Reproduction: Lab Project Number: 101/005/07: DI741701: 106409. Unpub lished study prepared by Bio
- Life Associates, Ltd. and Miles Agricultural Division. 301 p. ACCESSTION NO.: AC0023 Clinch, P.G. (1967). The residual contact toxicity to honey bees of insecticides sprayed on to white clover (Trifolium repens) in the labo ratory. New Zealand Journal of Agricultural Research, 10(2):289
- 300. ACCESSTION NO.: AC0008 Clinch, P.G. (1969). Laboratory determination of the residual fumigant toxicity to honey bees of insecticide sprays on white clover (Trifolium repens). New Zealand Journal of Agricultural Research, 12(1):162
- 170. ACCESSTION NO.: AA0Q01 Bartlett, B.R. (1966). Toxicity and acceptance of some pesticides fed to parasitic Hymenoptera and predatory coccinellids. Journal of Economic Entomology, 59(5):1142
- 1149. ACCES STION NO.: 00001949 Johansen, C.; Eves, J. (1969). Bee research investigations, 1969: Small
- scale bee poisoning tests with honey bees (HB) and alfalfa leafcutter bees (LB). Unpublished study received Sept. 15, 1971 under 1F1032; prepared by Washington State Univ., submitted by Hercules, Inc., Wilmington, Del.; CDL:091917
- H. ACCESSTION NO.: 00060628 Johansen, C.; Eves, J. (1969). Bee poisoning investigations, 1965: Report No. G
- 1705; Report No. 17338. Unpublished study, including letter dated June 12, 1 973 from C.A. Johansen to A.D. Cohick, received Mar 27, 1974 under 4F1485; prepared by Washington State Univ., Dept. of Entomology, submitted by Chemagro Corp., Kansas City, MO.; CDL:092011
- I. ACCESSTION NO.: 00036935 Atkins, E.L.; E.A. Greywood; R.L. Mac Donald (1975). Toxicity of pesticides and other agricultural chemicals to honey bees. Laboratory studies. Univ. of Californis, Division of Agricultural Science. Leaflet 2287. 38 pp. ACCESSTION NO.: 05008149 Gholson, L.E.; C.C. Beegle; R.L. Best; J.C. Owens (1978). Effects of several commonly
- used insecticides on cornfield carabids in Iowa. J. Econ. Entomol., 71(3):416
- 418. MRID: 40098001 Mayer, F.; Ellersieck, M. (1986) Manual of Acute Toxicity: Interpretation and Data Base 410 Chemicals and 66 Sp ecies of Fresh
- Water Animals. US Fish & Wildlife Service; Resource Publica tion (160): 579 p.

### 45 of 74

MRID: 404526
- 01 Forbis, A.D. (1987). Chronic Toxicity of 14 C
- DYLOX® to Daphnia magna Under Flow
- Through Test Conditions. Unpublished s tudy performed by Analytical Bio
- Chemistry Laboratories, Inc., Columbia, MO. Laboratory Final Report No. 35738. Study sponsored by Mobay Corporation, Stilwell, KS. Study initiated June 15, 1987 and completed July 6, 1987. MRID: 65495 Pickering, Q.H ., C. Henderson and A.E. Lemke. 1981. The Toxicity of Organic Phosphorous Insecticides to Different Species of Warm Water Fishes. U.S. Department of Health, Education and Welfare. Public Health Service. R.A. Taft Sanitary Engineering Center, Cincinnati, Ohio. MRID: 42571701 Gagliano, G. (1992) Early Life Stage Toxicity of Dylox Technical to the Rainbow Trout (Oncorhynchus mykiss) under Flow
- through Conditions: Lab Project Number: DL842201: 103928: Unpublished study prepared by Miles Incorporated. 19 2 p. MRID: 44499201 Drottar, K.; Krueger, H. (1998) Trichlorfon (Dylox): A 96
- Hour Shell Deposition Test with the Eastern Oyster (Crassostrea virginica): Lab Project Number: 149A
- 105: 108069. Unpublished study prepared by Wildlife International Ltd. 4 3 p. MRID: 44499202 Drottar, K.; Krueger, H. (1998) Trichlorfon (Dylox): A Flow
- Through Life
- Cycle Toxicity Test with the Saltwater Mysid (Mysidopsis bahia): Lab Project Number: 149A
- 106: 108070. Unpublished study prepared by Wildlife International Ltd. 55 p. Relates to L0000302. MRID: 42228301 Eigenberg, D. (1991) A Two - Generation Dietary Reproduction Study in Rats Using Technical Grade Trichlorfon (Dylox): Lab Project Number: 89
- 672
- EA . Unpublished study prepared by Mobay Corp. 1075 p. MRID: 40 818301 Grimes, J.; Jaber, M. (1988) DDVP: An Acute Oral Toxicity Study with the Bobwhite: Final Report: Project No. 246
- 102. Unpub
- lished study prepared by Wildlife International Ltd. 21 p. MRID: 22923 Hill, E.F.; Heath, R.G.; Spann, J.W.; et al. (1975 ) Lethal Dietary Toxicities of Environmental Pollutants to Birds: Special Scientific Report
-- Wildlife No. 191. (U.S. Dept. of the Interior, Fish and Wildlife Service, Patuxent Wildlife Research Center; unpublished report) MRID: 44233401 Redgrave, V. (199 7) Mallard Duck Dietary Reproduction and Tolerance Studies: DDVP: Lab Project Number: AVC 7/961821: AVC 7. Unpublished study prepared by Huntingdon Life Sciences Ltd. 243 p. MRID: 5467 Gaines, T.B. (1960) The acute toxicity of pesticides to rats. Toxico logy and Applied Pharmacology 2(1):88
- 99. (Also in unpublished submission received Feb 14, 1961 under PP0299; submitted by Chemagro Corp., Kansas City, Mo.; CDL:090320
- Q) MRID: 42483901 Tyl, R.; Myers, C.; Marr, M. (1992) Two - Generation Reproductive Toxicity Study of DDVP Administered in Drinking Water to CD (Sprague
- Dawley) Rats: Final Report: Lab Project Number 60C
- 4629
- 170. Unpublished study prepared by Research Triangle Institute. 1225 p.

### 46 of 74

MRID: 43890301 Ward, G.; Davis, J. (1995) DDVP Technical Grade: Chronic Life
- Cycle Toxicity to the Water Flea, Daphnia magna, Under Flow
- Through Test Conditions: Lab Project Number: J94030071: J9403007N. Unpublished study prepared by Toxikon Environmental Sciences. 74 p. MRID: 43788001 Davis, J. (1995) DDVP T echnical Grade: Toxicity to Embryos and Larvae of the Rainbow Trout, Oncorhynchus mykiss, Under Flow
- Through Conditions: Lab Project Number: J9403007M. Unpublished study prepared by Toxikon Environmental Sciences. 77 p. MRID: 43571408 Jones, F.; Davis, J. (1994) DDVP 4
- E Emulsifiable Concentrate: Acute Toxicity to the Mysid, Mysidopsis bahia, Under Flow
- through Test Conditions: Lab Project Numbers: J9403007J: J9403007B. Unpublished study prepared by Toxikon Environmental Sciences. 60 p. MRID: 43854301 Ward, S.; Davis, J. (1995) DDVP Technical Grade: Chronic Toxicity to the Mysid (Mysidopsis bahia) Under Flow Through Conditions: Lab Project Number: J9407006A. Unpublished study prepared by Toxikon Environmental Sciences. 90 p. MRID: 43571403 Jones, F. ; Davis, J. (1994) DDVP Technical Grade: Acute Toxicity to Sheepshead Minnow (Cyprinodon variegatus) Under Flow
- through Test Conditions: Lab Project Numbers: J9403007F: J9403007B. Unpublished study prepared by Toxikon Environmental Sciences. 59 p. MRID: 43790401 Ward, G.; Davis, J. (1995) DDVP Technical Grade: Toxicity to Embryos and Larvae of the Sheepshead Minnow (Cy

prinodon variegatus) Under Flow
- Through Test Conditions: Lab Project Number: J9407006B. Unpublished study prepared by Toxikon Environmental Sciences. 81 p.

### 47 of 74

Appendix A . Submitted Toxicity Data for Trichlorfon and DDVP. Studies classified as ‘unacceptable’ are excluded. TABLE A .1. Submitted Toxicity Data for Trichlorfon (The studies with the most sensitive endpoint for each taxon are highlighted). TAXON ENDPOINT FORMULATION MRID STUDY CLASS IFICATION COMMENTS Birds (Chronic) Mallard duck ( Anas platyrhynchos ) NOAEC =

27 mg/kg
diet LOAEC = 78 mg/kg
diet Technical (99.8%) 43019601 Acceptable Based on decrease in eggshell thickness (16% reduction compared to control) and percent viable em bryos (i.e., %of eggs set); 4 birds at the 235 concentration died after exhibiting clinical signs of toxicity; 1 control bird died Bobwhite quail ( Colinus virginianus ) NOAEC = 9

mg/kg
- diet LOAEC = 30 mg/kg
diet Technical (99.8%) 43119501 Acceptable Based on a decrease in hatchling survival (no eggshell thickness effects at any level

– highest = 85 ppm); there were 10 mortalties (1 control, 1 at the 8 ppm concentration, and 8 at the 85 ppm conc.) Terrestrial Invertebrates Honey bee ( Apis mellifera ) LC 50 > 1.20

lb a.i./acre Form

ulation (SP, 80%) AC0023

(Clinch, 1967) Supplemental Non
- guideline study; insecticide sprayed from tower
– honey bees enclosed with contaminated flowers for 1 hr (3 hrs after spray) ; no mortalities up to 24
- hr after exposure; only 1 conc. tested.

### 48 of 74 TAXON ENDPOINT FORMULATION MRID STUDY CLASS IFICATION COMMENTS Honey bee ( Apis mellifera ) LC 50 > 1.20

lb a.i./acre Form

ulation (SP, 80%) AC0008

(Clinch, 1969) Supplemental Non
- guideline study; test to mimic fumigant toxicity; bees exposed for 1 hr; no ‘fumigant toxicity’ noted for trichlorfon; only 1 conc. tested. Lady beetle ( Lindorus lophanthae) LC 50 >

0.477% a.i. in honey (w /w) = 4,770 ppm (some mo rtality, specifics not provided except <50%) Mealybug destroyer ( Cryptolaemus montrouzieri) LC 50 >

0.477% a.i. in honey (w /w) = 4,770 ppm (some mo rtality, speci fics not provided except <50%) Scale predator ( Aphytis melinus ) LC 50 =

0.477% a.i. in honey (w /w) = 4,770 ppm (up to 4
- days after exposure) Parasitic wasp ( Metaphycus luteolus ) LC 50 =

0.477% a.i. in honey (w /w) = 4,770 ppm (up to 4
- days after exp osure) Form

ulation (SP, 50%) AA0Q01

(Bartlett, 1966) Supplemental Non
- guideline; dietary study; pesticides mixed into honey bait; bees allowed to feed for 6 hrs, then held for 4 days; only 2 conc. tested.

Alfalfa leafcutter bee ( Megachile rotundata ) 65%

mo rtality (2 lb a.i./acre application rate)

– when exposed to Dylox SP (80%) ACC 00001949 (Johansen and Eves, 1969) Supplemental Non
- guideline; alfalfa treated using hand sprayer, bees were caged on treated foliage; mortality

### 49 of 74 TAXON ENDPOINT FORMULATION MRID STUDY CLASS IFICATION COMMENTS 8
-hr old residues evaluated 24
-hr post exposure; only 1 conc. tested Honey bee ( Apis mellifera ) 44%

mo rtality (2 lb a.i./acre application rate)

– when exposed to 3
-hr old residues Dylox SP (80%) ACC 00001949 (Johansen and Ev es, 1969) Supplemental Non
- guideline; alfalfa treated using hand sprayer, bees were caged on treated foliage; mortality evaluated 24
-hr post exposure; only 1 conc. tested Honey bee ( Apis mellifera ) 17%

mo rtality (1 lb a.i./acre application rate)

– when exposed to 3
-hr old residues; 0% with 2
- day old residues Dylox SP (50%) ACC 00060628 (Johansen and Eves, 1965) Supplemental Non
- guideline; alfalfa treated using hand sprayer, bees were caged on treated foliage; mortality evaluated 48
-hr post exposure; only 1 conc. tested Alkali bee ( Nomia melanderi) 31%

mo rtality (1 lb a.i./acre application rate)

– when exposed to 3
-hr old residues; 10% with 2
- day old residues Dylox SP (50%) ACC 00060628 (Johansen and Eves, 1965) Supplemental Non
- guideline; alfalfa treated u sing hand sprayer, bees were caged on treated foliage; mortality evaluated 48
-hr post exposure; only 1 conc. tested Leafcutter bee ( Megachile rotundata ) 5% mortality

(1 lb a.i./acre application rate)

– when exposed to 3
-hr old residues Dylox SP (50%) ACC 00060628 (Johansen and Eves, 1965) Supplemental Non
- guideline; alfalfa treated using hand sprayer, bees were caged on treated foliage; mortality evaluated 48
-hr post exposure; only 1 conc. tested Honey bee ( Apis mellifera ) LD 50 =

59.83 μg a.i./bee (acute contact); slope

– 2.81 Form

ulation ACC

00036935 (Atkins et al ., 1975) Acceptable A bell
- jar vacuum duster was used to apply the pesticide, mixed with pyrolite dust diluent, to bees; observations up to 96
- hrs post treatment Ground beetle 100% Form ulation (80%) ACC Supplemental Non
- guideline;

### 50 of 74 TAXON ENDPOINT FORMULATION MRID STUDY CLASS IFICATION COMMENTS (Scarites substria tus ) mo rtality at

1 lb a.i./acre 05008149 (Gholson et al. , 1978) soil surface sprayed with pesticide; beetles placed in soil and mo rtality evaluated after 5 days; only 1 conc. tested Ground beetle (Pterostichus chalcites ) 100%

mo rtality at 1 lb a.i./acre Form

ulation (80%) ACC

05008149 (Gholson et al. , 1978) Supplemental Non
- guideline; soil surface sprayed with pesticide; beetles placed in soil and mo rtality evaluated after 5 days; only 1 conc. tested Ground beetle (Bembidion rapidum ) 97.5%

mo rtality at 1 lb a.i./acre Form

ulation (80%) ACC

05008149 (Gholson et al. , 1978) Supplemental Non
- guideline; soil surface sprayed with pesticide; beetles placed in soil and mo rtality evaluated after 5 days; only 1 c onc. tested Ground beetle (Harpalus pensylvanicus ) 50%

mo rtality at 1 lb a.i./acre Form

ulation (80%) ACC

05008149 (Gholson et al. , 1978) Supplemental Non
- guideline; soil surface sprayed with pesticide; beetles placed in soil and mo rtality evaluated after 5 days; only 1 conc. tested Freshwater Invertebrates (Acute) Daphnia pulex EC 50 (48
-hr)

= 0.18 μg/L Technical 40098001 Supplemental (also reported in 40094602); raw data from M&E not legible Simocephalus serrulatus EC 50 (48
-hr)

= 0.70 μg/L Technical 400 98001 Supplemental (also reported in 40094602); no raw data available Simocephalus serrulatus EC 50 (48
-hr)

= 0.32 μg/L Technical 40098001 Supplemental No raw data available Gammarus lacustris EC 50 (96
-hr)

= 40 μg/L Technical 40098001 Supplemental Gamma rus pseudolimnaeus EC 50 (96
-hr)

= 108 μg/L Technical 40098001 Supplemental Gammarus pseudolimnaeus EC 50 (96
-hr)

= 275 μg/L Technical 40098001 Supplemental Gammarus EC 50 (96
-hr) Technical 40098001 Supplemental

### 51 of 74 TAXON ENDPOINT FORMULATION MRID STUDY CLASS IFICATION COMMENTS pseudolimnaeus = 90 μg/L Gammarus pseudolimnaeus EC 50 (96
-hr)

= 108 μg/L Technical 40098001 Supplemental Gammarus pseudolimnaeus EC 50 (96
-hr)

= 119 μg/L Technical 40098001 Supplemental Gammarus pseudolimnaeus EC 50 (96
-hr)

= >40 μg/L Technical 40098001 Supplemental Gammarus pseudolimnaeus EC 50 (96
-hr)

= 43 μg/L Technical 40098001 Supplemental Gammarus pseudolimnaeus EC 50 (96
-hr)

= 32 μg/L Technical 40098001 Supplemental Gammarus pseudolimnaeus EC 50 (96
-hr)

= 17 μg/L 80% wettable

powder 40098001 Supplemental Procambarus sp. EC 50 (96
-hr)

= 7,800 μg/L Technical 40098001 Supplemental Procambarus sp. EC 50 (96
-hr)

= 13,300 μg/L Technical 40098001 Supplemental Claassenia sabulosa EC 50 (96
-hr)

= 22 μg/L Technical 40098001 Supplemental Isogenus sp. EC 50 (96
-hr)

= 24 μg/L Technical 40098001 Supplemental Isogenus sp. EC 50 (96
-hr)

= 12 μg/L 80% wettable

powder 40098001 Supplemental Pteronarcella badia EC 50 (96
-hr)

= 11 μg/L Technical 40098001 Supplemental Not enough information available in the raw data to confirm the results Pteronarcella badia EC 50 (96
-hr)

= 100 μg/L Technical 40098001 Supplemental Pteronarcella badia EC 50 (96
-hr)

= 9.8 μg/L Technical 40098001 Supplemental Pteronarcella badia EC 50 (96
-hr)

= 5.3 μg/L Technical 40098001 Supplemental Adequate for RQ calculation; based o n analysis of raw data, the slope is 5.2 (C.I.: 2.6

– 7.9) Pteronarcys californica EC 50 (96
-hr)

= 35 μg/L Technical 40098001 Supplemental Freshwater Invertebrates (Chronic) Daphnia magna NOAEC =

0.0057 μg a.i./L LOAEC = 0.0086 μg a.i./L Technical 4045 2601 Acceptable Based on survival (all endpoints were affected in the study, the most sensitive was survival) Freshwater Fish (Acute) Coho salmon LC 50 (24
-hr)

= >4,110 Technical 40098001 Supplemental Flow
- through

### 52 of 74 TAXON ENDPOINT FORMULATION MRID STUDY CLASS IFICATION COMMENTS μg/L Cutthroat trout LC 50 (96
-hr)

= 2,70 0 μg/L Technical 40098001 Supplemental Cutthroat trout LC 50 (96
-hr)

= 6,800 μg/L Technical 40098001 Supplemental Cutthroat trout LC 50 (96
-hr)

= 5,750 μg/L Technical 40098001 Supplemental Cutthroat trout LC 50 (96
-hr)

= 1,680 μg/L Technical 40098001 Su pplemental Cutthroat trout LC 50 (96
-hr)

= 4,750 μg/L Technical 40098001 Supplemental Cutthroat trout LC 50 (96
-hr)

= 375 μg/L Technical 40098001 Supplemental Cutthroat trout LC 50 (96
-hr)

= 5,70 μg/L Technical 40098001 Supplemental Cutthroat trout LC 50 (96
-hr)

= 620 μg/L Technical 40098001 Supplemental Cutthroat trout LC 50 (96
-hr)

= 1,730 μg/L Technical 40098001 Supplemental “0 DAY DEGRA” Cutthroat trout LC 50 (96
-hr)

= 470 μg/L Technical 40098001 Supplemental “7 DAY DEGRA” Cutthroat trout LC 50 (96
-hr)

= 170 μg/L Technical 40098001 Supplemental “14 DAY DEGRA” Cutthroat trout LC 50 (96
-hr)

= 340 μg/L Technical 40098001 Supplemental “21 DAY DEGRA” Cutthroat trout LC 50 (96
-hr)

= 3,250 μg/L 80% wettable

powder 40098001 Supplemental Cutthroat trout LC 50 (96
-hr)

= 5,220 μg/L Technical 40098001 Supplemental Cutthroat trout LC 50 (96
-hr)

= 4,400 μg/L Technical 40098001 Supplemental Cutthroat trout LC 50 (96
-hr)

= 6,170 μg/L Technical 40098001 Supplemental Cutthroat trout LC 50 (96
-hr)

= 1,080 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 1,750 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 1,410 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 11,400 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 1,775 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 2,000 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 970 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 8,800 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 1,120 μg/L Technical 40098001 Supplemental

### 53 of 74 TAXON ENDPOINT FORMULATION MRID STUDY CLASS IFICATION COMMENTS Rainbow trout LC 50 (96
-hr)

= 700 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 700 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 1,380 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 355 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 210 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 280 μg/L Tec hnical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 700 μg/L 80% wettable

powder 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 700 μg/L 40.5% EC 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 1,400 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 4,250 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 1,020 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 1,820 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 860 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 72 μg/L Technical 40098001 Supplemental Not adequate for RQ calculation; legible raw data not available for review Rainbow trout LC 50 (96
-hr)

= 158 μg/L Technical 40098001 Supplemental Adequate for RQ calculation (reported as 156 in the M&E volume); no slope could be calculated Rainbow trout LC 50 (96
-hr)

= 1,400 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 3,500 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 5,850 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 167 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 3,500 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 4,500 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 310 μg/L Technical 40098001 Supplemental

### 54 of 74 TAXON ENDPOINT FORMULATION MRID STUDY CLASS IFICATION COMMENTS Rainbow trout LC 50 (96
-hr)

= 2,600 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 2,500 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 780 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 820 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 430 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 370 μg/L Technical 4009 8001 Supplemental Rainbow trout LC 50 (96
-hr)

= 580 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 780 μg/L 80% Wettable

poweder 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 2,400 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 1,100 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 430 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 960 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 860 μg/L Technic al 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 9,000 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 6,410 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 1,750 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 2,460 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 390 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 580 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 560 μg/L Technic al 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 700 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 360 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 860 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 1,000 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 1,100 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 570 μg/L Technical 40098001 Supplemental

### 55 of 74 TAXON ENDPOINT FORMULATION MRID STUDY CLASS IFICATION COMMENTS Rainbow trout LC 50 (96
-hr)

= 500 μg/L Technical 4 0098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 500 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 208 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 230 μg/L Technical 40098001 Supplemental Rainbow trout LC 5 0 (96
-hr)

= 160 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 1,000 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 820 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 562 μg/L Technical 4009800 1 Supplemental Rainbow trout LC 50 (96
-hr)

= 740 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 190 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 440 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 6,410 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 1,000 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 820 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 560 μg/L Technical 40098001 Su pplemental Rainbow trout LC 50 (96
-hr)

= 8,000 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 2,460 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 740 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 562 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 700 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 1,230 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 390 μg/L Technical 40098001 Supp lemental Rainbow trout LC 50 (96
-hr)

= 580 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 190 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 440 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 360 μg/L Technical 40098001 Supplemental

### 56 of 74 TAXON ENDPOINT FORMULATION MRID STUDY CLASS IFICATION COMMENTS Rainbow trout LC 50 (96
-hr)

= 780 μg/L Technical 40098001 Supplemental Rainbow trout LC 50 (96
-hr)

= 1,060 μg/L 80% Wettable

powder 40098001 Supplemental Atlantic salmon LC 50 (96
-hr)

= 1,400 μg/L Technical 40098 001 Supplemental Atlantic salmon LC 50 (96
-hr)

= 2,000 μg/L Technical 40098001 Supplemental Atlantic salmon LC 50 (96
-hr)

= 4,100 μg/L Technical 40098001 Supplemental Atlantic salmon LC 50 (96
-hr)

= 580 μg/L Technical 40098001 Supplemental Atlantic salmon LC 50 (96
-hr)

= 540 μg/L Technical 40098001 Supplemental Atlantic salmon LC 50 (96
-hr)

= 380 μg/L Technical 40098001 Supplemental Atlantic salmon LC 50 (96
-hr)

= 4,400 μg/L Technical 40098001 Supplemental Atlantic salmon LC 50 (96
-hr)

= 610 μg/L Tec hnical 40098001 Supplemental Atlantic salmon LC 50 (96
-hr)

= 300 μg/L Technical 40098001 Supplemental Atlantic salmon LC 50 (96
-hr)

= 2,970 μg/L Technical 40098001 Supplemental Atlantic salmon LC 50 (96
-hr)

= 10,400 μg/L Technical 40098001 Supplemental Brook trout LC 50 (96
-hr)

= 3,500 μg/L Technical 40098001 Supplemental Brook trout LC 50 (96
-hr)

= 2,500 μg/L Technical 40098001 Supplemental Brook trout LC 50 (96
-hr)

= 9,400 μg/L Technical 40098001 Supplemental Brook trout LC 50 (96
-hr)

= 1,100 μg/L Technical 40098001 Supplemental Brook trout LC 50 (96
-hr)

= 8,400 μg/L Technical 40098001 Supplemental Brook trout LC 50 (96
-hr)

= 3,400 μg/L Technical 40098001 Supplemental Brook trout LC 50 (96
-hr)

= 470 μg/L Technical 40098001 Supplemental Brook trout LC 50 (96
-hr)

= 240 μg/L Technical 40098001 Supplemental Brook trout LC 50 (96
-hr)

= 2,420 μg/L Technical 40098001 Supplemental Brook trout LC 50 (96
-hr)

= 620 μg/L Technical 40098001 Supplemental Brook trout LC 50 (96
-hr)

= 9,200 μg/L 80% Wettable

p owder 40098001 Supplemental Brook trout LC 50 (96
-hr)

= 500 μg/L Technical 40098001 Supplemental Brook trout LC 50 (96
-hr) Technical 40098001 Supplemental

### 57 of 74 TAXON ENDPOINT FORMULATION MRID STUDY CLASS IFICATION COMMENTS = 9,200 μg/L Brook trout LC 50 (96
-hr)

= 6,000 μg/L Technical 40098001 Supplemental Brook trout LC 50 (96
-hr)

= 960 μg/L Technical 40098001 Supplemental Brook trout LC 50 (96
-hr)

= 840 μg/L Technical 40098001 Supplemental Brook trout LC 50 (96
-hr)

= 650 μg/L Technical 40098001 Supplemental Brook trout LC 50 (96
-hr)

= 290 μg/L Technical 40098001 Supplemental Brook trout LC 50 (96
-hr)

= 5,500 μg/L 40% EC 40098001 Supplemental Lake trout LC 50 (96
-hr)

= 550 μg/L Technical 40098001 Supplemental Lake trout LC 50 (96
-hr)

= 1,030 μg/L Technical 40098001 Supplemental Fathead minnow LC 50 (96
-hr)

= 7,900 μg/L Technical 40098001 Supplemental Black bullhead LC 50 (96
-hr)

= 515 μg/L Technical 40098001 Supplemental Channel catfish LC 50 (96
-hr)

= 2,200 μg/L 40.5% EC 40098001 Supplemental Channel catfish LC 50 (96
-hr)

= 7,600 μg/L Technical 40098001 Supplemental Channel catfish LC 50 (96
-hr)

= 880 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 3,170 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= >50,000 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 50,000 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 10,300 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 10,300 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= >50,000 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 32,000 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 3,400 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 2,900 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr) Technical 40098001 Su pplemental

### 58 of 74 TAXON ENDPOINT FORMULATION MRID STUDY CLASS IFICATION COMMENTS = 14,500 μg/L Bluegill LC 50 (96
-hr)

= 4,500 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 1,720 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 1,720 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 940 μg/L 80% Wettable

powder 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 5,200 μg/L 40.5% EC 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 2,500 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 600 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 1,300 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 1,500 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 1,000 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 2,500 μg/L Technical 40098001 Supple me ntal Bluegill LC 50 (96
-hr)

= 2,700 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 1,650 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 2,200 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 1,050 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 1,050 μg/L 80% Wettable

powder 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 15,000 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 3,300 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 39,000 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 800 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 35,500 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 31,000 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 3,500 μg/L Technical 40098001 Supplemental

### 59 of 74 TAXON ENDPOINT FORMULATION MRID STUDY CLASS IFICATION COMMENTS Bluegill LC 50 (96
-hr)

= 7,200 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 2,820 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 9,200 μg/L Te chnical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 12,300 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 7,200 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 5,000 μg/L Technical 40098001 Supplemental Bluegill LC 50 (9 6
-hr)

= 1,730 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 3,150 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 2,250 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 410 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 8,700 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 14,000 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 5,800 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 5,000 μg/L Technical 4 0098001 Supplemental Bluegill LC 50 (96
-hr)

= 2,800 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 2,000 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 234 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 5,20 0 μg/L 40.5% EC 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 3,360 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 13,000 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 15,000 μg/L Technical 40098001 Supplemental Bluegil l LC 50 (96
-hr)

= 45,000 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 40,000 μg/L Technical 40098001 Supplemental

### 60 of 74 TAXON ENDPOINT FORMULATION MRID STUDY CLASS IFICATION COMMENTS Bluegill LC 50 (96
-hr)

= 6,800 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 9,600 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 8,100 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 2,350 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 2,250 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 2,250 μg/L Technical 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 1,050 μg/L 80% Wettable

powder 40098001 Supplemental Bluegill LC 50 (96
-hr)

= 1,880 μg/L Technical 40098001 Supplemental Largemouth bass LC 50 (96
-hr)

= 3,450 μg/L Technical 40098001 Supplemental Yellow perch LC 50 (96
-hr)

= 3,450 μg/L Technical 40098001 Supplemental Fathead minnow LC 50 (96
-hr)

= 110,000 μg/L Bluegill L C 50 (96
-hr)

= 3,800 μg/L Goldfish LC 50 (96
-hr)

= 100,000 μg/L Guppy LC 50 (96
-hr)

= 7,200 μg/L Technical 65495 Supplemental Adequate for RQ c alculation; No analytical verification was reported for any of the bioassays.
Bluegill LC 50 (96
-hr)

= 2,200 μg/L Technical 91766 Acceptable Rainbow trout LC 50 (96
-hr)

= 1,600 μg/L Technical 91766 Acceptable Freshwater Fish (Chronic) Rainbow trout NOAEC =

110 μg a.i./L LOAEC = 234 μg a.i./L Technical 425717
- 01 Acceptable Early life
- stage study; endpoint based on increased time to swim up Estuarine/Marine Invertebrates (Acute) Eastern oyster ( Crassostrea virginica ) EC 50 >114

mg a.i./L Technical 444992
- 01 Acceptable 96
- hr shell
deposition study; NOAEC = 83 mg a.i./L (based on 16% decrease in shell deposition) Estuarine/Marine Invertebrates (Chronic) Mysid ( Mysidopsis bahia ) NOAEC =

3.1 μg a.i./L LOAEC = T echnical 444992
- 02 Acceptable Flow
- through, life
- cycle study; endpoints based on decreased

### 61 of 74 TAXON ENDPOINT FORMULATION MRID STUDY CLASS IFICATION COMMENTS 6.7 μg a.i./L number of neonates produced, decreased survival, dreased weight, and decreased length Thalassiosire pseudonana LC 50 = >50

mg a.i./L

### 62 of 74

TABLE A .2 . S ummary of th e Studies with the Most Sensitive Endpoints from S ubmitted Toxicity Data for DDVP. TAXON ENDPOINT FORMULATION MRID STUDY CLASS IFICATION COMMENTS Birds (Acute) Bobwhite quail ( Colinus virginianus ) LD 50 = 8.8 mg

a.i./kg bw Technical 40818301 Acceptable Birds (Sub -

Acute) Ring
- necked pheasant (Phasianus colchicus ) LC 50 = 568

mg a.i./kg
diet Technical 0022923 Acceptable
Birds (Chronic) Mallard duck ( Anas platyrhynchos ) NOAEC = 5

mg a.i./kg
diet LOAEC = 15 mg a.i./kg
diet Technical 44233401 Acceptable Based on reduced eggshell thickness, eggs laid, and number of viable embryos Mammals (Acute

) Laboratory rat (Rattus norvegicus ) LD 50 = 56 mg

a.i./kg
-bw Technical 0005467 Acceptable Mammals (Chronic) Laboratory rat (Rattus norvegicus ) NOAEC = 20

mg a .i./kg
diet LOAEC = 80 mg a.i./kg
diet Technical 42483901 Acceptable Based on reduced fertility and pup weight

Terrestrial Invertebrates Honey bee ( Apis mellifera ) LD 50 = 0.5 μg

a.i./bee (contact) Technical 00036935 Acceptable Freshwater Invertebrates (Acute) Water flea ( Daphnia pulex) EC 50 = 0.066

μg a.i./L Technical 40098001 Acceptable Freshwater Invertebrates (Chronic) Water flea ( Daphnia magna ) NOAEC =

0.0058 μg a.i./L LOAEC = 0.0122 μg a.i./L Technical 43890301 Acceptable Based on reduced egg production and grow th (length and weight) Freshwater Fish (Acute) Cutthroat trout ( Oncorhynchus clarki) LC 50 = 170

μg a.i./L Technical 40098001 Acceptable Freshwater Fish (Chronic)

### 63 of 74 TAXON ENDPOINT FORMULATION MRID STUDY CLASS IFICATION COMMENTS Rainbow trout ( Oncorhynchus mykiss ) NOAEC =

5.2 μg a.i./L LOAEC = 10 .1 μg a.i./L Technical 43788001 Acceptable Based on decreased post
hatch larval survival Estuarine/Marine Invertebrates (Acute) Mysid ( Americamysis bahia ) EC 50 = 19.1

μg a.i./L Technical 43571408 Acceptable Estuarine/Marine Invertebrates (Chronic) Mysid ( Americamysis bahia ) NOAEC =

1.48 μg a.i./L LOAEC = 3.25 μg a.i./L Technical 43854301 Acceptable Based on reduced grow

th (weight and length) Estuarine/Marine Fish (Acute) Sheepshead minnow ( Cyprinodon variegates ) LC 50 = 7,350

μg a.i./L Technical 435 71403 Acceptable
Estuarine/Marine Fish (Chronic) Sheepshead minnow ( Cyprinodon variegates ) NOAEC =

960 μg a.i./L LOAEC = 1840 μg a.i./L Technical 43790401 Acceptable Based on reduced survival and length

### 64 of 74

Appendix B . The Risk Quotient Method and Level s of Concern The Risk Quotient Method is the means used b y EFED to integrate the results of exposure and ecotoxicity data. For this method, Risk Quotients (RQs) are calculated b y dividing exposure estimates by the acute and chronic ecotoxicity values (i. e., RQ = EXPOSURE/TOXICI TY). These RQs are then compared to OPP's levels of concern (LOCs). These LOCs are criteria used b y OPP to indicate potential risk to non
- target organisms and the need to consider regulatory action. EFED has defined LOCs for acute risk, potential restricted use classification, and for endangered species. The criteria indicate that a pesticide used as directed has the potential to cause adverse effects on non
- target organisms. LOCs currentl y a ddress the following risk presumption categories: (1) acute
- there is a potential for acute risk; regulatory action may be warranted in addition to restricted use classification; (2) acute restricted use
- the potential for acute risk is high, but this may be mitigated through restricted use classification; (3) acute endangered species
- the potential for acute risk to endangered species is high, regulatory action may be warranted; and (4) chronic risk
- the potential for chronic risk is high, regulatory action may be warranted. Currentl y, EFED does not perform assessments for chronic risk to plants, acute or chronic risks to non
- target insects, or chronic risk from granular/bait formulations to mammalian or avian species. The ecotoxicity test values (i.e., measurement endpoints) used in the acute and chronic RQs are derived from required studies. Examples of ecotoxicity values derived from short
- term laboratory studies that assess acute effects are: (1) LC50 (fish and birds), (2) LD50 (birds and mammals), (3) EC50 (aquatic plants and aquatic invertebrates), and (4) EC25 (terrestrial plants). Examples of toxicity test effect levels derived from the results of long
- term laboratory studies that assess chronic effects are: (1) the Lowest Observed Adverse Effect Concentration (LOAEC) (birds, f ish, and aquatic invertebrates), and (2) the No Observed Adverse Effect Concentration (NOAEC) (birds, fish and aquatic invertebrates). The NOAEC is generall y used as the ecotoxicity test value in assessing chronic effects. Risk presumptions, along with the corresponding RQs and LOCs are summarized in Table B 1.

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Table B 1. Agency risk quotient (RQ) metrics and levels of concern (LOC) per risk class. Risk Class Risk Description RQ LOC Aquatic Animals (fish and invertebrates) Ac ute Potential for effe cts to non - listed animals from acute

exposures Peak EEC/LC 50 1 0.5 Ac ute Restricted Use Potential for effects to animals from acute exposures

Risks may be mitigated through restricted use classification Peak EEC/LC 50 1 0.1
Ac ute Listed Species Listed speci es may be potentially affected by acute

exposures Peak EEC/LC 50 1 0.05 60
- day EEC/NOEC (fish) Chronic Potential for effects to non
- listed and listed animals from

chronic exposures 21
- day EEC/NOEC (invertebrates) 1

Terrestrial Anim als (mammals and bir ds) EEC 2/LC 50 (Dietary) Ac ute Potential for effects to non
- listed animals from acute

exposures EEC/LD 50 (Dose) 0.5

EEC 2/LC 50 (Dietary) Ac ute Restricted Use Potential for effects to animals from acute exposures

Risks may be mitigated through restricted use classification EEC/LD 50 (Dose) 0.2

EEC 2/LC 50 (Dietary) Ac ute Listed Species Listed species may be potentially affected by acute

exposures EEC/LD 50 (Dose) 0.1

Chronic Potential for effects to non
- listed and listed animals from

chronic expos ures EEC 2/NOAEC 1 Plants Non
- Listed Potential for effects to non
- target, non - listed plants from

exposures EEC/ EC 25 1 EEC/ NOEC Listed Plant Potential for effects to non
- target, listed plants from

exposures EEC/ EC 05 1

1 LC 50 or EC 50 . 2 Based on upper bound Kenaga values.

### 66 of 74

Appendix C . Data Call- In Tables The Environmental Fate and Effects Division (EFED) has completed a Data Call
- In (DCI) table for the trichlorfon (and DDVP) environmental fate and effects data gaps identified in registration review. The effects data gaps may change if relevant toxicity data are identified from the ECOTOX literature review. The attached DCI tables, which include the guideline number and study title for required data, also provides a rationale for requiring th e data, an explanation of how the data will be used, and a brief description of how the data could impact the Agency ’s future decision
- making. Trichlorfon: Guideline Number: 835.2120 Study Title: Hydrolysis Rationale for Requiring the Data Acceptabl e data have not been provided to quantify the hydrolysis of trichlorfon. According to Code of Federal Regulations 40 (CFR40 2007) Part 158 Subpart D (data requirements for pesticides) hydrolysis data are required for pesticides with terrestrial or aquatic uses. Since trichlorfon uses are classified as terrestrial and aquatic, hydrolysis data for trichlorfon should be submitted to fulfill OPPTS Guideline 835.2120. Practical Utility of the Data How will the data be used? These data are used to estimate the degradation of trichlorfon in aquatic systems and ultimately to derive aquatic EECs using PRZM/EXAMS. How could the data impact the Agency’s future decision - making? In the case that these data are unavailable at the time risk assessments are conducted, it will be assumed that trichlorfon is stable to hydrolysis. If trichlorfon does degrade due to hydrolysis, this assumption will result in overestimates of the concentrations of trichlorfon in the environment.
Guideline Number: 835.2 410 Study Title: P hotodegradation in soil Rationale for Requiring the Data Acceptable data have not been provided to quantify the photolysis of trichlorfon in water. According to Code of Federal Regulations 40 (CFR40 2007) Part 158 Subpart D (data requirements for pestici des) aqueous photolysis data are required for pesticides with terrestrial or aquatic uses. Since trichlorfon uses are classified as terrestrial and aquatic, aqueous photolysis data for trichlorfon should be submitted to fulfill OPPTS Guideline 835.2 410
. Practical Utility of the Data How will the data be used? These data are used to characterize the degradation of trichlorfon in soil. How could the data impact the Agency’s future decision - making? In the case that these data are not submitted, it will be assumed that trichlorfon is stable to photolysis on soil.

### 67 of 74

Guideline Number: 835.4300 Study Title: Aerobic Aquatic Metabolism Rationale for Requiring the Data Acceptable data have not been provided to quantify the metabolism of trichlorfon under aerobic aquatic conditions. According to Code of Federal Regulations 40 (CFR40 2007) Part 158 Subpart D (data requirements for pesticides) aerobic aquatic metabolism are required for pesticides with terrestrial or aquatic uses. Since trichlorfon uses are cl assified as terrestrial and aquatic, aerobic aquatic metabolism data for trichlorfon should be submitted to fulfill OPPTS Guideline 835.4300. Practical Utility of the Data How will the data be used? These data are used to estimate the degradation of tri chlorfon in aquatic systems and ultimately to derive aquatic EECs using PRZM/EXAMS. How could the data impact the Agency’s future decision - making? In the case that these data are unavailable at the time risk assessments are conducted, PRZM/EXAMS input pa

rameter guidance default values will be employed to account for aerobic aquatic metabolism. Guideline Number: 835.4400 Study Title: Anaerobic Aquatic Metabolism Rationale for Requiring the Data Acceptable data have not been provided to quantify the metabolism of trichlorfon under anaerobic aquatic conditions. According to Code of Federal Regulations 40 (CFR40 2007) Part 158 Subpart D (data requirements for pesticides) anaerobic aquatic metabolism data are required for pesticides with terrestrial or aquatic uses. Since trichlorfon uses are classified as terrestrial and aquatic, anaerobic aquatic metabolism data for trichlorfon should be submitted to fulfill OPPTS Guideline 835.4400. Practical Utility of the Data How will the data be used? These data are used to estimate the degradation of trichlorfon in aquatic systems and ultimately to derive aquatic EECs using PRZM/EXAMS. How could the data impact the Agency’s future decision - making? In the case that these data are unavailable at the time risk a ssessments are conducted, PRZM/EXAMS input parameter guidance default values will be employed to account for anaerobic aquatic metabolism.
Guideline Number: 835.1240 Study Title: adsorption/desorption Rationale for Requiring the Data Acceptable data have not been provided to quantify the adsorption/desorption characteristics of trichlorfon in U.S. soils. According to Code of Federal Regulations 40 (CFR40 2007) Part 158 Subpart D (data requirements for pesticides) adsorption/desorption data are required for pesticides with terrestrial uses. Since trichlorfon uses are considered to be terrestrial, an acceptable study should be submitted to fulfill OPPTS Guideline 835.1240. This study should define Kd 

### and KOC 

### values of trichlorfon in U.S. soils. It is preferred that this study be conducted using a batch equilibrium method. Practical Utility of the Data

### 68 of 74

How will the data be used? These data are used to estimate the transport of trichlorfon from treatment sites to aquatic systems and ultimately to derive aquatic EECs using PRZM/EXAMS. How could the data impact the Agency’s future decision - making? In the absence of these data, EFED will assume that there is no sorption of trichlorfon to soils or organic matter on the treatment site. In order to implement this in derivation of aquatic EECs, a KOC 

### value of 0 will be used to parameterize PRZM/EXAMS. Input of a KOC 

### value >0 is expected to result in lower aquatic EECs. If acceptable data are provided, the uncertainties associated with this assumption will b e reduced. Guideline Number: 835.6200 Study Title: Aquatic Field Dissipation Rationale for Requiring the Data At this time, no acceptable studies are available to describe the dissipation of trichlorfon under aquatic field conditions. According to Code of Federal Regulations 40 (CFR40 2007) Part 158 Subpart D (data requirements for pesticides), aquatic field dissipation data are required for pesticides with aquatic uses. Since trichlorfon uses are classified as aquatic, aquatic field dissipation dat a for trichlorfon should be submitted to fulfill OPPTS Guideline 835.6200. Practical Utility of the Data How will the data be used? These data are used to characterize the fate of trichlorfon in the aquatic environment resulting from direct applications to water. How could the data impact the Agency’s future decision - making? These data are useful to validate laboratory fate data of trichlorfon with a field study that accounts for all of the fate processes studied under laboratory conditions (e.g., hydro lysis, photolysis).
Guideline Number: 835.6100 (7) , 835.6200 (7) Study Title: Environmental Chemistry Methods Rationale for Requiring the Data Independently validated analytical methods for residues in soil and water (environmental chemistry methods) submitted by the registrant are used to evaluate analyses described in submitted environmental fate and ecological effects studies. Submitted analytical methods are also used by various Federal, State, Tribal, and local agencies to detect and monitor resi dues that are or are suspected to be in environmental compartments due to outdoor uses and accidental releases. Therefore, availability of these analytical methods is necessary in order to protect human health and the environment from trichlorfon residues in the environment. Independent laboratory validations for submitted analytical methods are necessary to confirm the levels of detection and quantitation reported in registrant
-prepared validations. Use of trichlorfon may impact surface water quality du e to runoff of rain water and drift of residues. Therefore, analytical methods for are necessary for detecting trichlorfon residues in water and in soil or sediment. Practical Utility of the Data

### 69 of 74

How will the data be used? In the absence of independently validated environmental chemistry methods, submitted environmental fate and ecological effects data may not be reviewable and entities outside the Agency may lack chemical
- specific methods for analyses in environmental compartments. Independently validated environmental chemistry methods will be used to evaluate the submitted environmental fate and ecological effects data and will be made available to the public to support monitoring for trichlorfon residues
. How could the data change the Agency’s decis ion, or impact the Agency’s future decision making? Risk assessment conclusions could be altered if they are not supported by either study data or environmental monitoring detections that are based on independently validated environmental chemistry metho ds. Furthermore, while not directly related to Agency decision
- making, independently validated environmental chemistry methods are necessary in order to protect human health and the environment from use of trichlorfon. Guideline Number : 850.2100 Study Title : Avian Acute Oral Toxicity Test (mallard duck or bobwhite quail and a passerine species) Rationale for Requiring the Data No acceptable acute avian oral toxicity data were submitted for trichlorfon. The new Part 158 data requirements [40 CFR Par t 158 (CFR 40 2007)] specify that acute avian oral toxicity data be submitted for either mallard duck or bobwhite quail and a passerine species. The available chronic toxicity data for mallard ducks and bobwhite quails demonstrate that trichlorfon can caus e toxic effects in these birds. In addition, avian data for other organophosphate (OP) insecticides, including dimethoate, show that a passerine species, such as the red
-winged blackbird, are one order of ma gnitude more sensitive than other tested bird spe cies to acute OP insecticide exposure (USEPA 2008). Therefore, an avian oral toxicity test is required for passerine birds and either the mallard duck or the bobwhite quail , as specified in 40 CFR Part 158. A passerine study protocol must be submitted for review by the Agency prior to initiation of this study. Practical Utility of the Data How will the data be used? Acute avian oral toxicity data will be used to identify potential risks to birds from acute exposure to trichlorfon. The data will reduce uncertainties associated with the current risk assessment for birds and will improve the Agency’s understanding of the potential effects of trichlorfon on terrestrial species. If oral acute toxicity data are not submitted for any bird , than risk to birds f rom acute exposure to trichlorfon will be a ssumed
. How could the data impact the Agency’s future decision - making? If future endangered species risk assessments are performed without these data, the Agency would have to assume that trichlorfon “may affect” listed birds directly (and listed species from other taxa indirectly), and use of trichlorfon and its formulated products may need to be restricted in areas where listed species could be exposed. The lack of these data will limit the flexibility the Agency and registrants have in coming into compliance with the Endangered Species Act and could result in use restrictions for trichlorfon use that are unnecessarily severe. Guideline Number: 850.2200 Study Title: Avian Dietary Toxicity Test (mallard duc k and bobwhite quail) Rationale for Requiring the Data No acceptable sub
- acute avian dietary toxicity data were submitted for trichlorfon. The new Part

### 70 of 74

158 data requirements [40 CFR Part 158 (CFR 40 2007)] specify that avian dietary toxicity data be sub mitted for both a waterfowl and upland game species. The available chronic toxicity data for mallard ducks and bobwhite quails demonstrate that trichlorfon can cause toxic effects in these birds. Therefore, an avian dietary toxicity test is required for mallard ducks and bobwhite quails as specified in 40 CFR Part 158. Practical Utility of the Data How will the data be used? Sub
- acute avian dietary toxicity data will be used to identify potential risks to birds from acute exposure to trichlorfon. The data will reduce uncertainties associated with the current risk assessment for birds and will improve the Agency’s understanding of the potential effects of trichlorfon on terrestrial species. If dietary toxicity data are not submitted for any bird , than risk to birds from dietary exposure to trichlorfon will be a ssumed
. How could the data impact the Agency’s future decision - making? If future endangered species risk assessments are performed without these data, the Agency would have to assume that trichl orfon “may affect” listed birds directly (and listed species from other taxa indirectly), and use of trichlorfon and its formulated products may need to be restricted in areas where listed species could be exposed. The lack of these data will limit the flexibility the Agency and registrants have in coming into compliance with the Endangered Species Act and could result in use restrictions for trichlorfon use that are unnecessarily severe. Guideline Number : 850.1075 Study Title : Fish Acute Toxicity Test, Estuarine/Marine Rationale for Requiring the Data Acute toxicity data are not available for estuarine and marine fish. The updated Part 158 data requirements , published in October 2007, specify that acute toxicity data are required on one estuarine/marine mollusk (guideline fulfilled), one estuarine/marine invertebrate (guideline not fulfilled), and one estuarine/marine fish (guideline not fulfilled) for terrestrial (food crop, feed crop, and nonfood), aquatic food crop , and nonfood (outdoor), forestry, and resi dential outdoor uses. Trichlorfon has terrestrial (turf), aquatic nonfood (ornamental/bait ponds) and residential outdoor uses registered, and therefore, the acute estuarine/marine organism toxicity studies are required. In the absence of these data, an acute
-to - chronic ratio (ACR) would normally be derived; and the acute toxicity to estuarine and marine fish would be estimated based on the ACR for freshwater fish. However, there are currently no toxicity data (acute or chronic) for estuarine/ma rine fish, therefore, an ACR cannot be derived. In addition, three of the four reported ecological incidents associated with the use of trichlorfon have involved fish kills. Practical Utility of the Data How will the data be used? Estuarine/marine fish acute toxicity data will be used to determine the potential for trichlorfon to affect fish species in estuarine/marine environments. The data will reduce uncertainties associated with the current risk assessment for estuarine/marine fish and will improve the Agency’s understanding of the potential effects of trichlorfon on aquatic animals. In the absence of data specific for these fish, data from freshwater fish species will be used as a surrogate for estuarine/marine fish. How could the data impact the Agency’s future decision - making? Using toxicity data from a freshwater species as a surrogate for estuarine/marine species increases the uncertainty for assessing risks to estuarine/marine species in screening
- level assessments.

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Additionally, i f future endangered species risk assessments are performed without these data, the Agency would have to presume risk to listed estuarine/marine fish species in the absence of such data for trichlorfon. Therefore, the use of trichlorfon and its formulated products may need to be restricted in areas where listed species could be exposed. The lack of these data will limit the flexibility the Agency and registrants have in coming into compliance with the Endangered Species Act and could result in use restrictions for tric hlorfon that are unnecessarily severe. Guideline Number : 850.1035 Study Title : Mysid Acute Toxicity Test Rationale for Requiring the Data Although, acute toxicity data are available for an estuarine/marine mollusk, no acute data are currently availab le for a non
- mollusk estuarine/marine invertebrate. The updated Part 158 data requirements , published in October 2007, specify that acute toxicity data are required on one estuarine/marine mollusk (guideline fulfilled), one estuarine/marine invertebrate (guideline not fulfilled), and one estuarine/marine fish (guideline not fulfilled) for terrestrial (food crop, feed crop, and nonfood), aquatic food crop , and nonfood (outdoor), forestry, and resi dential outdoor uses. Trichlorfon has terrestrial (turf) , aquatic nonfood (ornamental/bait ponds) and residential outdoor uses registered, and therefore, the acute estuarine/marine organism toxicity studies are required. In the absence of these data, an acute
-to - chronic ratio (ACR) would normally be derived; and the acute toxicity to estuarine/marine invertebrates would be estimated based on the ACR for freshwater invertebrates. However, the freshwater invertebrate data necessary for calculating the ACR are not available. Chronic data are not available for the mo st acutely sensitive freshwater species (Pteronarcella badia ). Practical Utility of the Data How will the data be used? Estuarine/marine invertebrate acute toxicity data will be used to determine the potential for trichlorfon to affect non
- mollusk invertebrate species in estuarine/marine environments. The data will reduce uncertainties associated with the current risk assessment for estuarine/marine invertebrates and will improve the Agency’s understanding of the potential effects of trichlorfon on aquatic animals. In the absence of data specific for these invertebrates, data from freshwater invertebrate species will be used as a surrogate for estuarine/marine invertebrates. How could the data impact the Agency’s future decision - making? Using toxicity data from a freshwater species as a surrogate for estuarine/marine species increases the uncertainty for assessing risks to estuarine/marine species in screening
- level assessments. Additionally, i f future endangered species risk assessments are performed without these data, the Agency would have to presume risk to listed non
- mollusk estuarine/marine invertebrate species in the absence of such data for trichlorfon. Therefore, the use of trichlorfon and its formulated products may need to be restricted in areas where listed species could be exposed. The lack of these data will limit the flexibility the Agency and registrants have in coming into compliance with the Endangered Species Act and could result in use restrictions for trichlorfon that are unnecessari ly severe. Guideline Number : 850.1400 Study Title : Fish Early Life- Stage Toxicity Test , Estuarine/Marine Rationale for Requiring the Data Chronic toxicity data are not available for estuarine and marine fish. In the absence of these data, an acute -to - chronic ratio (ACR) would normally be derived; and the chronic toxicity to estuarine

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and marine fish would be estimated based on the ACR for freshwater fish. However, there are currently no toxicity data (acute or chronic) for estuarine/marine fish, therefore, an ACR cannot be derived. Additionally, due to the potential use pattern of trichlorfon , exposure to estuarine/marine environments is possible. Therefore, an early life
- stage toxicity study is required for estuarine/marine fish , as specified in 40 CFR Part 158. Practical Utility of the Data How will the data be used? Estuarine/marine fish chronic toxicity data will be used to determine the potential for trichlorfon to affect fish species in estuarine/marine environments. The data will reduce u ncertainties associated with the current risk assessment for estuarine/marine fish and will improve the Agency’s understanding of the potential effects of trichlorfon on aquatic animals. In the absence of data specific for these fish, data from freshwater fish species will be used as a surrogate for estuarine/marine fish. How could the data impact the Agency’s future decision - making? Using toxicity data from a freshwater species as a surrogate for estuarine/marine species increases the uncertainty for ass essing risks to estuarine/marine species in screening
- level assessments. Additionally, i f future endangered species risk assessments are performed without these data, the Agency would have to presume risk to listed estuarine/marine fish species in the abs ence of such data for trichlorfon. Therefore, the use of trichlorfon and its formulated products may need to be restricted in areas where listed species could be exposed. The lack of these data will limit the flexibility the Agency and registrants have in coming into compliance with the Endangered Species Act and could result in use restrictions for trichlorfon that are unnecessarily severe. Guideline Number : 850.4100, 850.4150 Study Title : Terrestrial Plant Toxicity Test, Tier I (Seedling Emergence an d Vegetative Vigor) Rationale for Requiring the Data Toxicity data for terrestrial plants are not available for trichlorfon. T he current 40 CFR Part 158 data requirements, require Tier I level seedling emergence and vegetative vigor terrestrial plant data for all insecticides. Additionally, other OPs are known to be phytotoxic ( e.g ., tribufos, a plant defoliant)
. Therefore, Tier I plant toxicity studies (seedling emergence and vegetative vigor) are required for terrestrial plants , as specified in 40 CF R Part 158. Practical Utility of the Data How will the data be used? Vegetative vigor and seedling emergence data for terrestrial plants will be used to determine the potential for trichlorfon to affect non
-target plant species in the terrestrial environment. The data will reduce uncertainties associated with the current risk assessment for terrestrial plants and will improve the Agency’s understanding of the potential effects of trichlorfon on terrestrial plants
. In the absence of data specific for th ese plants, risk to terrestrial plants will be assumed. How could the data impact the Agency’s future decision - making? Because terrestrial plants form the basis of the food chain in many terrestrial habitats, a solid understanding of the potential risks to terrestrial plants is essential for sound environmental risk management decision
- maki ng . Without terrestrial plant data for trichlorfon, the Agency cannot determine if the current application rates for trichlorfon may result in direct adverse effects to terrestrial plants and/or indirect effects resulting from reduction in the prey base and/or loss of habitat/cover
. If future endangered species risk assessments are performed without these data, the Agency would have to presume risk to non
-target terrestrial plants from use of trichlorfon. Therefore, use of trichlorfon and its formulated products may need to be restricted in areas where

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listed species could be exposed. The lack of these data will limit the flexibility the Agency and registrants have in co ming into compliance with the Endangered Species Act and could result in use restrictions for trichlorfon that are unnecessarily severe. Guideline Number : 850.4400 Study Title : Aquatic plant toxicity (Tier I) Rationale for Requiring the Data Trichlorfon toxicity data for vascular and non
-vascular aquatic plants are not available. Based on the 40 CFR Part 158 data requirements, Tier I level non
-target aquatic plant data are required for all insecticides. Additionally, other OPs are known to be phyotoxic ( e.g ., tribufos, which is a defoliant) . Therefore, non
-target aquatic plant data for algae and vascular plants are required for trichlorfon at the Tier I level. Practical Utility of the Data How will the data be used? Data from Tier I aquatic plant toxicity studies will be used to estimate potential risks to aquatic vascular and non
-vascular plant s associated with the use of trichlorfon . The data will reduce uncertainties associated with the current risk assessment for aquatic plants and will impro ve the Agency’s understanding of the potential effects of trichlorfon on aquatic plants . In the absence of Tier I data, risks for both vascular and non
- vascular aquatic plants will be presumed. How could the data impact the Agency’s future decision - makin g? Because aquatic vascular and non
-vascular plants form the basis of the food chain for aquatic habitats and significantly contribute to overall water quality, a solid understanding of the potential risks to aquatic plants is essential for sound environmental risk management decision
- making
. Without aquatic plant data for trichlorfon, the Agency cannot determine if the current application rates for trichlorfon may result in direct adverse effects to aquatic plants and/or indirect effects resulting from re duction in the prey base and/or loss of habitat/cover
. If future endangered species risk assessments are performed without these data, the Agency would have to assume that trichlorfon “may affect” aquatic plants directly (and listed species from other tax a indirectly via reduction in prey base and/or habitat), and use of trichlorfon may need to be restricted in areas where listed species could be exposed. The lack of these data will limit the flexibility the Agency and registrants have in coming into comp liance with the Endangered Species Act and could result in use restrictions for trichlorfon which are unnecessarily severe. 

### DDVP: Guideline Number : 850.2100 Study Title : Avian Acute Oral Toxicity Test Rationale for Requiring the Data Acceptable acute avian oral toxicity data were submitted for exposures of bobwhite quail to DDVP; however, data are not available for passerines, which are required under the new 40 CFR Part 158 (CFR 40 2007) data requirements for conventional pesticides (72 FR 60934; USEPA 2007 c ). The available data for bobwhite quails show that DDVP is classified as very highly toxic to birds on an acute exposure. In addition, avian data for other organophosphate (OP) insecticides, including dimethoate, show that a passerine species, such as the red
-winged blackbird, are one order of magnitude more sensitive than other tested bird species to acute OP insecticide exposure. Therefore, an avian oral toxicity test is required for passerine birds, as specified in 40 CFR Part 158. A passerine study protocol must be submitted for review by the Agency prior to initiation of this study. Practical Utility of the Data

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How will the data be used? Acute avian oral toxicity data will be used to identify potential risks to birds from acute exposure to DDVP from the use of trichlorfon. The data will reduce uncertainties associated with the current risk assessment for birds and will improve the Agency’s understanding of the potential effects of trichlorfon on terrestrial species. If oral acute toxic ity data are not submitted for passerines , than risk to passerines from acute exposure to DDVP from the use of trichlorfon will be a ssumed
. How could the data impact the Agency’s future decision - making? If future endangered species risk assessments are performed without these data, the Agency would have to assume that trichlorfon “may affect” listed passerine species directly (and listed species from other taxa indirectly), and use of trichlorfon and its formulated products may need to be restricted in a

reas where listed species could be exposed. The lack of these data will limit the flexibility the Agency and registrants have in coming into compliance with the Endangered Species Act and could result in use restrictions for trichlorfon use that are unnece ssarily severe. Guideline Number : 850.4100, 850.4150 Study Title : Terrestrial Plant Toxicity Test, Tier I (Seedling Emergence and Vegetative Vigor) Rationale for Requiring the Data Toxicity data for terrestrial plants a re not available for DDVP
. T h e current 40 CFR Part 158 data requirements, require Tier I level seedling emergence and vegetative vigor terrestrial plant data for all insecticides. Additionally, other OPs are known to be phytotoxic ( e.g ., tribufos, a plant defoliant)
. Therefore, Tier I plant toxicity studies (seedling emergence and vegetative vigor) are required for terrestrial plants , as specified in 40 CFR Part 158. Practical Utility of the Data How will the data be used? Vegetative vigor and seedling emergence data for terrestrial plants will be used to determine the potential for DDVP (from the use of trichlorfon) to affect non
-target plant species in the terrestrial environment. The data will reduce uncertainties associated with the current risk assessment for terrestrial plants and will improve the Agency’s understanding of the potential effects of trichlorfon on terrestrial plants
. In the absence of data specific for these plants, risk to terrestrial plants will be assumed. How could the data impact the Agency’s future deci sion - making? Because terrestrial plants form the basis of the food chain in many terrestrial habitats, a solid understanding of the potential risks to terrestrial plants is essential for sound environmental risk management decision
- maki ng . Without terrest rial plant data for DDVP, the Agency cannot determine if the current application rates for trichlorfon may result in direct adverse effects to terrestrial plants and/or indirect effects resulting from reduction in the prey base and/or loss of habitat/cover
. If future endangered species risk assessments are performed without these data, the Agency would have to presume risk to non
-target terrestrial plants from use of trichlorfon. Therefore, use of trichlorfon and its formulated products may need to be rest ricted in areas where listed species could be exposed. The lack of these data will limit the flexibility the Agency and registrants have in coming into compliance with the Endangered Species Act and could result in use restrictions for trichlorfon that are unnecessarily severe. Guideline Number : 850.4400 Study Title : Aquatic plant toxicity (Tier I) Rationale for Requiring the Data DDVP toxicity data for vascular and non
-vascular aquatic plants are not available. Based on the 40

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CFR Part 158 data requirements, Tier I level non
-target aquatic plant data are required for all insecticides. Additionally, other OPs are known to be phyotoxic ( e.g ., tribufos, which is a defoliant) . Therefore, non
-target aquatic plant data for algae and vascular plants are required for DDVP at the Tier I level. Practical Utility of the Data How will the data be used? Data from Tier I aquatic plant toxicity studies will be used to estimate potential risks to aquatic vascular and non
-vascular plant s from DDVP exposure associ ated with the use of trichlorfon . The data will reduce uncertainties associated with the current risk assessment for aquatic plants and will improve the Agency’s understanding of the potential effects of trichlorfon on aquatic plants . In the absence of T ier I data, risks for both vascular and non
-vascular aquatic plants will be presumed. How could the data impact the Agency’s future decision - making? Because aquatic vascular and non
-vascular plants form the basis of the food chain for aquatic habitats and significantly contribute to overall water quality, a solid understanding of the potential risks to aquatic plants is essential for sound environmental risk management decision
- making
. Without aquatic plant data for DDVP, the Agency cannot determine if th e current application rates for trichlorfon may result in direct adverse effects to aquatic plants and/or indirect effects resulting from reduction in the prey base and/or loss of habitat/cover
. If future endangered species risk assessments are performed without these data, the Agency would have to assume that trichlorfon “may affect” aquatic plants directly (and listed species from other taxa indirectly via reduction in prey base and/or habitat), and use of trichlorfon may need to be restricted in areas where listed species could be exposed. The lack of these data will limit the flexibility the Agency and registrants have in coming into compliance with the Endangered Species Act and could result in use restrictions for trichlorfon which are unnecessarily severe.