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UNXTED STrlTES E NMEN'TAI, PROTECTION ilGF,NGY 

WASHINGTON D.C. 

CfFFlf E OF 

PREVEIUTIOl. PESTICIDES AND 

TOXIC SUDSTALCES 

PC Code: 107901 

DP Barcodes: D339605 

Date: March 5,2008 

DRINKING WATER ASSESSMENT 1 

SUBJECT: Revised Drinking Water As essment for reregistration of triforine for use on 

ornamentals. S 

FROM: Keara Moore, Chemist 

Environmental Risk Bra 

Environmental Fate and 

THRU: Tom Bailey, Branch Chief 

Environmental Risk Branch 111 J 

Environmental Fate and cts Division (7507P) 

TO: Christine Olinger, RRBI 

Health Effects Division 

ivision (7508P) 

Attached is the sessment for the reregistration eligibility 

decision for tri sed to remove Confidential Business 

ons or characterization of potential drinking 

nements are necessary, please contact Keara 

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Drinking W Assessment for 

the Reregistratio Decision for 

Triforine 

[Original: 0ctbber 19,2007; D3396061 

N,N'- [l,4-piperazine-diylbis(2~,2-triehloroethy~dene)] bis [formamide] 

CAS ~e~istr) Number: 26644-46-2 

Prepared by: 

Keara Moore, Chemist 

PC 

Reviewed by: 

Jim Hetrick, PhD, Senior Scientist 

Code: 107901 

U. S. Environmental Protection Agency 

Offie of Pesticide Programs 

Environmental Fate and Effects Division 

Environmental Risk Branch 111 

1200 Pennsylvania Ave., NW 

Mail Code 7507P 

Washington, DC 20460 
I. EXECUTIVE SUMMARY I 

This document reports the Tier 1 drinking ater exposure assessment for triforinel conducted to 

support the human health risk assessment f r 1 the Reregistration Eligibility Decision (RED). 

Triforine is a fungicide and insecticide regi tered for outdoor residential use on ornamentals, 

primarily roses. It is applied as an aerosol pray or through hose-end or tank-type sprayers at a 

maximum application rate of 0.46 lb a.i./A, with multiple applications allowed at 7-10 day 

intervals. I 

Triforine is moderately persistent in soil a half-life of one to several months and it degrades 

rapidly in water through hydrolysis and with half-lives of several days. 

Transformation in soil leads primarily and carbon dioxide as end products, but 

laboratory studies show formation of in some environments at levels up 

unknown degradate, construed to be 

its hydrate4. No of the degradates and this 

assessment 

Based on triforine's use pattern and its fate properties, aquatic exposure at the 

scale of a drinking water watershed is is intended for small-scale use by 

cans or in volumes of one pint to one 

quart, which can treat a the California Department of 

Pesticide Regulation applicators is at rates of 

<0.05 lb any triforine that 

of chronic 

exposure. 

11. PROBLEM FORMULATION 

This is a Tier I drinking water uses modeling to estimate the groundwater 

and surface water in drinking water source water (pretreatment) that are highly vulnerable. This initial tier 

provides estimated exposure 

See Appendix B for structure. 

4 B for structure. 
111. ANALYSIS I 

A. use' Characterization I 

~ 

Triforine is registered for use on roses, flowers, shrubs, and shade trees. 

It is used to control black spot, and to kill aphids, mites, and other 

insects. Triforine has three Rose & Floral Spray (0.1 % a.i., Reg. 

No. 239-2467), applied spray can; and Ortho Rose 

Disease Control (6.5% Insect & Disease Control Formula 

I11 (3.25% a.i., Reg. diluted with water to 0.0021 lb 

a.i./gal for sprayers. All products 

are labeled for outdoor residential use only. 

Based on the assumption that 5 gallons of solution are applied per 1000 ft2, the application 

rate is 0.01 1 lb a.i./1000 R2, equivalent to a.i./A. Given the individual, residential nature 

of the use, though, it is unlikely that large be treated. The largest available formulation 

contains 1 quart of product, equivalent to of dilute solution, which would be sufficient 

to treat 0.3 A. Labels indicate that for 2 to 3 applications may be needed, and for 

disease control, applications as disease conditions persist, with no 

maximum number specified. 7-1 0 days for most uses but can be 

applied to azaleas at 2-3 day that triforine products are generally 

used by gardeners who make enthusiasts who make multiple 

applications. 

AD) estimates that more than 100,000 

ates. Additional local use data are 

gulation, which compiles Pesticide Use 

users . The PUR reports that in 2005, 

400 applications of triforine totaling 

ed 10/10/2007). This is not a 

rs, which is not likely to be the 

ent of large areas at the 

B. Environmental Fate and 

Laboratory fate studies show that is moderately persistent in 

soil and degrades rapidly in study found low sorption 

to moderately mobile 

measurement of 

In soil, 
degradation with a half-life on the scale of although a quantitative half-life could not be 

and low recoveries (MRID 4238041 1; 

Triforine was found to transform through 

the DT,, in three soils was 

observed to be 7 to 28 4323 1903, Acceptable; 

MRID 4323 1904, was examined as well and 

In most cases, 

degradates are available in Appendix B. 

A terrestrial field dissipation in which two apple orchards, in New York 

and California, were treated with each at rates of 0.75 lb a.i./A with seven day 

application intervals. This use would be expected for currently registered 

uses. In one site, triforine was a half-life of 133 days, while on the other 

site, the observed half-life was analyzed for the parent compound and 

so did not consider dissipation not adequate to determine if 

triforine leached to groundwater. 

Triforine may reach surface water through runoff, and/or erosion. In aquatic environments, 

it degrades rapidly through hydrolysis at (tlI2: 2.9 to 3.1 d; MRID 42647702) and 

through photolysis (dark corrected tlI2: 4 42647701). No data for aquatic metabolism 

are available. The major degradates hydrolysis were WOS-2379 and an 

unidentified compound assumed to was formed at a 

maximum of approximately 60% to approximately 15% by the 

end of the study; day 3 1. The of WOS-2379 reach 

approximately 20% on day 1 1 day 3 1. No additional 

environmental fate data are 

C. Drinking Water Exposure Modeling 

Based on the limited use pattern and of triforine, exposure in drinking water 

is expected to be low. Tier 1 screening level estimated drinking 

water concentrations assumptions are required in 

modeling exposure orted EDWCs are expected to be overestimates, but 

the extent of overestimation cannot be The following is a description of the models 

used, the model input parameters, and of the output from these simulations. 

1. Models 

Screening level estimated drinking water c: ncentrations (EDWCs) of triforine were generated 9' using the Tier I models FIRST, for surface ater, and SCIGROW, for groundwater. Input 

parameters were selected based on laborato y fate data in accordance with EFED's input 

parameter guidance. Models, input parame er guidance, and additional information about the 

. i 5 
models' assumptions and uncertainties are 

httn://ww\v.e~a. gav/n~19efed 1 /~nodcls!wate 

SCIGROW (version 2.3; dated July 29,20( 

estimate pesticide concentrations found in 1 

developed by regressing the results of Pros 

Index of Leaching Potential (RILP). The F 

soil-water partition coefficient. The output 

might be expected in shallow unconfined a 

FIRST (version 1.1 .O; dated January 1,20C 

screening tool to estimate pesticide concen 

FIRST is a single-event model (one runoff 

applications. FIRST is hardwired to repres 

by the Office of Pesticide Programs to asse 

on a real reservoir, Shipman City Lake in I 

contamination. The single runoff event mo 

reservoir. This amount can be reduced due 

to soil in the field. FIRST also uses a Perci 

within the watershed that is planted to the I 

was applied in this assessment because the] 

the entire watershed is planted with omamc 

to overly conservative risk estimates. 

2. Modeling Approach and Input Pard 

Tables 1 and 2 summarize the model input 

These parameters were selected in accorda 

2002a). The maximum single application 1 

given the manner in which triforine produc 

of application rate in lbs a.i./A may not be 

number of applications is assumed to be tvr 

do not restrict use to a maximum number c 

throughout the season, so it is likely that sc 

Some minor uses also allow an application 

expected to be minor given the conservativ 

the watershed with all users applying on th 

Registrant-submitted data for triforine inch 

The aerobic soil metabolism modeling inp~ 

bound on the mean (61.9 d) and for SCIGP 

partitioning coefficients, both models use E 

non-sand value (36 rnl/&,), and SCIGROP 

no aerobic aquatic metabolism data availal: 

stable to aquatic metabolism with hydrolys 

and the dark corrected photolysis half-life, 

railable at the EPA's water modeling website, 

I) is a regression model used as a screening tool to 

,oundwater used as drinking water. SCIGROW was 

:ctive Ground Water studies against the Relative 

LP is function of aerobic soil metabolism and the 

)f SCIGROW represents the concentrations that 

lifers under sandy soils. 

) is a metamodel of PRZM and EXAMS used as a 

ations found in surface water used as drinking water. 

vent), but can account for spray drift from multiple 

nt the Index Reservoir, a standard water body used 

s drinking water exposure (OPP, 2002). It is based 

inois, that is known to be vulnerable to pesticide 

:s a maximum of 8% of the applied pesticide into the 

o degradation on the field and the effects of binding 

~t Cropped Area (PCA) factor to adjust for the area 

odeled crop. A PCA of unity (the most protective) 

is no PCA for ornamental uses. This assumes that 

ltals treated with triforine, an approach likely to lead 

vleters 

arameter values used in FIRST and SCIGROW. 

:e with EFED's input parameter guidance (EFED, 

te of 0.46 lb a.i./A is used for modeling although, 

; are applied, the traditional agricultural expression 

:presentative of typical use. For this assessment, the 

with an application interval of seven days. Labels 

applications and state that applications can be made 

ie users apply triforine more often than twice a year. 

nterval of two days. These uncertainties are 

initial assumption that triforine is used throughout 

same day. 

ie three measured aerobic soil metabolism half-lives. 

for FIRST is the upper 90th percentile confidence 

)W, the input is the mean (42.9 d). For soil-water 

,c. Of five measured values, FIRST uses the lowest 

uses the median value (99 ml/a,). Because there are 

; and hydrolysis is rapid, triforine is assumed to be 

I as the rate-determining aquatic process (t,,,: 3. I), 

d, is used. 
Application Rate (lb a.i./A) 

Number of Applications I Triforine Use Closure Memo 

(Case No. 2720). 

The label does not specify maximum 

Current labels. number of applications, but two is 

assumed to be protective. Interval between Applications 

(days) 

Percent Cropped Area 

I 

1 

Organic Carbon Partition 

Coefficient (KO,; mL/goc) 

Aerobic Soil Metabolism Half-life 

(days) 

Most protective. 

MRID: 

42304101. 

MRIDs: 

43231903, 

43231904. 

Current labels. 

Product 

Chemistry 

Wetted in? 

Some minor uses allow a 2 day 

application interval. 

--- 

No PCA for ornamentals. 

Lowest non-sand value. 

(36, 88,99, 11 8, 122 mL/goc) 

90" percentile upper confidence 

bound on the mean 

(23.2,49.2,56.4 d) 

Default. 

Triforine Use Closure Memo 

(Case No. 2720) Method of Application Ground 

spray 

Solubility in Water @ 2ooc, 

unbuffered (mg/L or ppm) 

Aerobic Aquatic Metabolism Halflife (days) 

No data are available. Assumed that 

hydrolysis is the rate-determining 

aquatic process. 

Hydrolysis Half-life @ pH 7 

(days) 

MRID: 1 42647703. I Single measured value. 

Aquatic Photolysis Half-life @ 

PH 7 (days) 

Triforine Use Closure Memo Current label. I (Case No. 2720) I 

MRID: 1) 42647701. 

Maximum Application Rate 

(lb a.i./A) 

Number of Applications per Year 

Organic Carbon Partition Coefficient 

(K,; mL/goc) 

Single dark-control corrected value. 

Aerobic Soil Metabolism Half-life 

(days) 

2 

99 

Assumed. 

MRID: 

42304101. 

MRID: 

42.9 1 1 4323 1903, 

43231904. 

No maximum specified on label. 

Median value 

(36, 88,99, 118, 122 mLIg,). ---- 

Mean value 

(23.2,49.2,56.4 d). 
3. Modeling Results I 

For surface water, the modeled EDWCs and annual average exposure are 85.1 ppb and 

0.84 ppb, respectively. For and average exposure estimates are 0.43 

ppb. Modeling output files in Appendix A. 

Surface water EDWCs are based on FIRST and represent untreated surface water 

concentrations. The one-in-1 0-year peak is used for acute endpoints and the 

one-in- 1 0-year annual average endpoints. Groundwater 

EDWCs are based on that might be 

expected in shallow used for both acute 

and chronic endpoints. 

The estimated concentrations provided in th s assessment are conservative estimates of 

concentrations in drinking water. If dietary 1, 'sks require refinement, higher tiered crop-specific 

and location-specific models and modeling gcenarios can be used. 

D. Monitoring Data 1 

There were no national-scale monitoring found for this assessment. This is based on a 

search of the U.S. Geological Service Water Quality Assessment database (NAWQA, 

2007) and the USGSIEPA Reservoir Program (Blomquist et al., 2001). 

E. Drinking Water Treatment 

IV. CHARACTERIZATION 

There is no available information on water treatment effects on triforine. 

The estimated concentrations were generated from Tier 1 models and 

are conservative estimates of drinking water. Tier 1 

modeling is based on sites and includes 

protective assumptions FIRST, the Tier 1 

surface water model, agricultural fields 

and may not be 

A major uncertainty assumes that the entire watershed has been 

treated with triforine. Given the nature triforine use, this is unlikely and so leads to overly 

protective EDWCs. Another the reported EDWCs are for the parent only and 

do not consider potential The rapid hydrolysis of triforine limits its 

exposure in drinking exposure to the degradates. 
V. REFERENCES I 

I 

.B. Birchfield. 200 1. 

Sacramento, CA. 

Environmental Fate and Effects Division. . Guidance for Selecting Input Parameters in 

U. S. Environmental 

Environmental Fate and Effects Division. 2 05. FIRST (F)IFRA (1)ndex (R)eservoir 

(S)creening (T)ool. Tier 1 Model for Drinki g Water Exposure: User's Manual. 

htt~://www.e~~a.novi~r)~efedl /models/wates ." first users manuaf.htm 

NAWQA. 2007. USGS National Water Quality 

Geological Survey. Available at:,' 

http://infotrek.er.usgs.gov/traverse/r!p=NA7NQA:HOME:37655 

2007. 

Office of Pesticide Programs. 2000. Part A. 

Drinking Water Assessments. 

Assessment Data Warehouse. United States 

1952889201 9. Accessed August, 

Guidance for Use of the Index Reservoir in 

httl~:ii.c7iww.e-~a.aov~o~pfeadl/trac/science/reservoir.~df 
Modeling and Outputs 

FIRST V. 1.1.0; January 1, 200 7 

RUN No. 1 FOR triforine I ON ornamental * INPUT VALUES * 

-------_--_--______------------- ................................... 

RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE %CROPPED INCORP 

ONE (MULT ) INTERVAL Koc (PPM ) (%DRIFT) AREA (IN) ~~~~~~~~~~~~~~~~~~~~------------ ___--_--___-__--------------------- 

.460 ( -885) 2 7 36.0 1 28.0 GROUND( 6.4) 100.0 -0 

METABOLIC DAYS UNTIL HYDROLYSI PHOTOLYSIS METABOLIC COMBINED 

PEAK DAY (ACUTE ) 

CONCENTRATION CONCENTRATION 

85.145 -835 

SCIGRO W v.2.3; July 29, 2003 

Application Number of Total Use Koc Soil Aerobic 

rate (lb/acre) applications ( b/acre/yr) (ml/g) metabolism (days) 

SC IGROW 

groundwater screening cond (ppb) ................................. 

FOR AQUATIC PESTICIDE 

SciGrow version 2.3 

chemica1:triforine 

time is 10/11/2007 15: 4:11 

EXPOSURE 
APPENQIX B: Structures 

N-[piperazine- 1 -yl-(trichloromethy1)methyl ne] 

forrnamide hydrochloride r 

piperazine 

x HCl 
Hydrate of WOS-23 79 1 

1 -(1 -formamido-2,2,2- trich1oro)-ethyl-4-(2, - 

dihydroxy- 1 -oxo-ethyl)-piperazine 2