### UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON D.C., 20460

PC Code: 0 80805

DP Barcode: 357096, 357099

Date : June 19, 2009



### MEMORANDUM

SUBJECT: Prometryn (CAS Reg. No. 7287

- 19

- 6 ) Tier I D r inking Water Assessm ent

for the Proposed New Uses on Carro ts, Okra, Parsley, Cilantro, Celeriac

,

a nd Leafy Petioles

FROM: Silvia C. Termes, Chemist

Environmental Fate and Effects Division

Environmental Risk Branch III

TO: Barbara Madden

Risk Integration, Minor Use & Emergency Response Branch

Registration Division

THRU: Dana Spatz, Branch Chief

Environmental Fate and Effects Division

Environmental Risk Branch III

The Environmental Fate and Effects Division has completed a Tier I Drinking Water

Assessment for r egistration of proposed new uses on carrots, okra, parsley, cilantro,

celeriac and leafy petioles . These proposed new uses have been included in the existing

labels of two end

- use products containing prometryn as the active ingredient:

Caparol 4L ( 44. 4% prometryn; EPA Reg. No. 100

- 62 0 ; Syngenta )

Prometryn 4L Herbicide (44 .4 % prometryn by weight; EPA Reg. No.66222

- 15 ;

Makhteshim Agan of North America, Inc).

The exposure concentrations in drinking water drawn from surface water were estimated

using the Tier I simulation FIRST (Version 1.1.1 ). Concentrations of prometryn in

ground water were estimated using the Tier I SCI

- GROW (Version 2.3 ) regression

model. This assessment addresses concentrations of parent only; no degradates were

included.

1

### Result s of Tier I Estimates (FIRST and SCI

- GROW)

Table 1 summarize s the Tier 1 estimated concentrations in surface and ground water.

Application information was extracted from the proposed labels.

Table 1

. Estimated Concentrations of Prometryn in Drin king Water Drawn from

Surface Water (FIRST) and from Ground Water (SCI

- GROW)

Crop Application

Information Peak Day (acute)

Concentration, μg/L

Surface water Annual Average

(Chronic) C onc. , μg/L

, Surface water Ground

Water

, μg/L

Carrots 3 Applications @ 2

lb ai/acre, 30 days

apart , ground 377.4 15 7.9 23.2

Okra 1 application @ 1.5

lb ai/acre, ground 96.7 40.5 6.0

Cilantro 1 application @ 1.6

lb ai/acre , ground 103.2 43.2 6.2

Parsley 3 applications at 0.5

lb ai/acre, 30 days

apart , ground 94.3 39.5 5.8

Celeriac 1 application @ 4 lb

ai/acre, ground 257.9 107.9 15.5

Leafy Petioles 1 application @ 2 lb

ai/acre , ground 129.0 54.0 8.0

Cotton 1 application @ 2.8

lb ai/acre, aerial

, 0.20 PCA 42.0 17.8 11.2



### Table 2 summarizes the exposure modeling inp ut parameters.

Table 2. Model Input Parameters

Physical

- chemical Properties and

Environmental Fate Input parameters Available Data Selected Value for

Modeling Source

Molecular Weight , g/mole 241

. 35 241.35 Product chemistry

Solubility in Water, mg/L 3 3 33 Product chemistry

Vapor Pressure (25 deg) 1.6E

- 6 torr 1.6 E

- 6 torr Product chemistry

Henry’s Law Constant, atm

- m3

- mole

- 1 N /A 9.1 E

- 9 (est.) Estimated (EPIWin,

Version 4.0)

Hydrolysis half

- life, days Stable 0 MRID495737

- 04

Photolysis in Water, days Stable 0 MRID495737

- 04

Aerobic Soil Metabolism half

- life. days 270 days (1

- soil) 3x 270

810 days (as per

Input Parameter

Guidance) MRID 48338 01

Anaerobic Aquatic Metabolism half

- life N /A

- N/A

Aerobic Aquatic Metabolism Half

- life N /A 2x 810

1620 days ( as per

Input Parameter

Guidance) N/A

Sorption Coefficients, K

oc Sand : 246

Loamy sand : 1 69

Silt loam : 117

Silty clay loam : 448 244 (as per Input

Parameter Guidance) MRID 00148338



### 2

### Summary of the Environmental Fate of Prometryn

Prometryn is a methylthio

- (symmetric) triazine. The chemical names (CAS and IUPAC)

are presented below together with the CAS Registry Number and chemical structure:

U.S. EPA PC Code: 080805

CA DPR Chemical Code: 502

IUPAC: N 2 

### ,N 4



### - diisopropyl

- 6

- methylthio

- 1,3,5

- triazine

- 2,4

- diam ine

CAS : N 2 

### ,N 4



### - diisopropyl

- 6

- methylthio

- 1,3,5

- triazine

- 2,4

- diamine

CAS Reg. No .: 7287

- 19

- 6

Chemical Formula : C 10 

### H 19 

### N 5 

### S

SMILES: CSc1nc(NC(C)C)nc(NC(C)C)n1

Chemical Structur e:

Metabolites of Prometryn

Name: Prom etryn aerobic soil metabolite (27% after one year incubation)



### CAS Name: 1,3,5

- Triazin

- 2(1H)

- one, 4,6

- bis((1

- methylethyl)amino)

-

IUPAC: 2,4

- bis(isopropylamino)

- 6

- hydroxy

- s

- triazine

CAS Reg No. 7374

- 53

- 0

3

### N

NH

2 

### N H

N N S

H

3 

### C CH

3



### CH

3



### Name: Prometryn aerobic soil metabolite (1.1% aft er one year incubation)

IUPAC: 2

- amino

- 4isopropylamino

- 6

- methylthio

- s

- triazine (GS

- 1154)

The environmental fate properties of prometryn, along with the major and minor

degradates detected in the submitted environmental fate and transport studies are

pre sented in Table 3

.

Table 3. E nvironmental Fate and Transport Behavior of Prometyrn

Study Value Major Degradates

Minor Degradates MRID # Study

Classification

Abiotic

Hydrolysis Stable at pH 5, 7, and 9 None 49573704 Acceptable

Direct Aqueous

Ph otolysis Stable None 49573705 Acceptable

Soil Photolysis Stable None 49573706 Acceptable

Aerobic Soil

Metabolism t 1⁄2 270 days; (One soil)

Sandy Soil 2,4

- bis(isopropylamino)

- 6

- hyd roxy

- s

- triazine (GS

11526, 27% o f the applied

radioactivity after 360 days

2

- amino

- 4isopropyla mino

6

- methylthio

- s

- triazine

(GS

- 1154) ; 1.1% at 30 days 00148338 Acceptable

Anaerobic Soil

Metabolism 

### t 1⁄2 

### 90 days

Stable 41155509 Acceptable

Anaerobic

Aquatic

Metabolism No data submitted No data

- N/A

Aerobic Aquatic

Metabo lism No data submitted No data

- N/A

163

- Mobility in

Soil

, Batch

equilibrium

Adsorption/

Desorption 

### K Freundlich, Adsorpotion 0.86 (agricultural sand) to

3.18 (silty clay loam);

add other soils GS 11 526 mobile to very

mobile ( Freudlich K ad s 7.1

to 0.5)

GS

- 11354 very mobile

( Freudlich K ad s 0.63

- 1.9) 49573713

418759 01

41875902

41875903

41875904

41875905 Acceptable



### 4Study Value Major Degradates

Minor Degradates MRID # Study

Classification

163

- 2 Volatility

from Soil

(Laboratory) Sand soil

Volatility was minimal,

0.99% prometryn

volatilized by 30 days No 41875906 Acceptable

T errestrial Field

Dissipation 

### t 1⁄2 Cotton CA, 105 days



### t 1⁄2 Cotton CA 71 days



### t 1⁄2 Cotton TX 14

- 30

days



### t 1⁄2 Cotton TX 14 days Prometryn was not detected

below 45 cm

CS

- 11354 detected at 120

cm soil depth Acceptable (for

flowable

concentrate)

Aquatic Field

Dissipation No data Not applicable Not

applicable N/A



### According to the submitted physical

- chemical and environmental fate data, the

degradation of prometryn is driven by micro bial (biotic) activity and not by abiotic

processes; however, biotransfor mation is slow. The major biotransformation product is

GS

- 115 26. The low Freundlich adsorption coefficient of prometryn suggests that the

chemical has the potential to run off and/or leach to ground water. Prometryn is stable to

hydrolysis and direct pho tolysis in aqueous media.

Prometryn and its degradates are very mobile to mobile in soil. Potential transport

mechanisms include runoff to surface water

, leaching to ground water, spray drift, and

secondary drift of volatilized or soil

- bound residues lea ding to deposition onto nearby or

more distant ecosystems.

T he US Geological Survey (USGS) has reported data on the presence of pesticides in rain

and wet deposition in four USA agricultural watersheds. Among other pesticides,

prometryn was detected in r ain and wet deposition in California

.

5

### Modeling Outputs

- FIRST

CARROTS

A. 3 applications 30 days apart @ 2 lb ai/acre

RUN No.1330 FOR Prometryn ON Carrots * INPUT VALUES *

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

ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) AREA (IN)

-------------------------------------------------------------------- .000( 5.849) 3 30 244.0 33.0 GROU ND( 6.4) 87.0 .0

FIELD AND RESERVOIR HALFLIFE VALUES (DAYS)

--------------------------------------------------------------------

METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED

(FIELD) RAIN/RUNOFF (RESERVOIR) (RES.

- EFF) (RE SER.) (RESER.)

--------------------------------------------------------------------

810.00 2 N/A .00

- .00 ****** 1620.00

UNTREATED WATER CONC (MICROGRAMS/LITER (PPB)) Ver 1.1.0 JAN 1, 2007

------------------------------- ------------------------------------- PEAK DAY (ACUTE) ANNUAL AVERAGE (CHRONIC)

CONCENTRATION CONCENTRATION

--------------------------------------------------------------------

377.368 157.873

B. One application @ 2 lb ai/acre

RUN No. 12 FOR Prometryn ON Carrot * INPUT VALUES *

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

ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) AREA (IN)

-------------------------------------------------------------------- 2.000( 2.000) 1 1 244.0 33.0 GROUND( 6.4) 87.0 .0

FIELD AND RESERVOIR HALFLIFE VALUES (DAYS)

------------------ --------------------------------------------------

METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED

(FIELD) RAIN/RUNOFF (RESERVOIR) (RES.

- EFF) (RESER.) (RESER.)

---------------------------------------------------------------- ----

810.00 2 N/A .00

- .00 ****** 1620.00

UNTREATED WATER CONC (MICROGRAMS/LITER (PPB)) Ver 1.1.0 JAN 1, 2007

-------------------------------------------------------------------- PEAK DAY (ACUTE) ANNUAL AVER AGE (CHRONIC)

CONCENTRATION CONCENTRATION

--------------------------------------------------------------------

128.977 53.952



### 6C. Two applications@ 2 lb/acre, 30 days apart

RUN No. 122 FOR Prometryn ON Carrots * INPUT VALUES *

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

ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) AREA (IN)

--------------------------------------------- ----------------------- 2.000( 3.949) 2 30 244.0 33.0 GROUND( 6.4) 87.0 .0

FIELD AND RESERVOIR HALFLIFE VALUES (DAYS)

--------------------------------------------------------------------

METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED

(FIELD) RAIN/RUNOFF (RESERVOIR) (RES.

- EFF) (RESER.) (RESER.)

--------------------------------------------------------------------

810.00 2 N/A .00

- .00 ****** 1620.00

UNTREATED WATER CONC (M ICROGRAMS/LITER (PPB)) Ver 1.1.0 JAN 1, 2007

-------------------------------------------------------------------- PEAK DAY (ACUTE) ANNUAL AVERAGE (CHRONIC)

CONCENTRATION CONCENTRATION

------------------------------------- -------------------------------

254.740 106.565

OKRA

A. One application at 1 .5 lb ai/acre

RUN No. 21 FOR Prometryn ON Okra * INPUT VALUES *

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

ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) AREA (IN)

-------------------------------------------------------------------- .500( 1.500) 1 1 244.0 33.0 GROUND( 6.4) 87.0 .0

FIELD AND RE SERVOIR HALFLIFE VALUES (DAYS)

--------------------------------------------------------------------

METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED

(FIELD) RAIN/RUNOFF (RESERVOIR) (RES.

- EFF) (RESER.) (RESER.)

------------------ --------------------------------------------------

810.00 2 N/A .00

- .00 ****** 1620.00

UNTREATED WATER CONC (MICROGRAMS/LITER (PPB)) Ver 1.1.0 JAN 1, 2007

------------------------------------------------------------------ -- PEAK DAY (ACUTE) ANNUAL AVERAGE (CHRONIC)

CONCENTRATION CONCENTRATION

--------------------------------------------------------------------

96.733 40.464



### 7b. Two applications @ 0.75 lb ai 30 days apart

RUN No. 22 FOR Prometryn ON Okra * INPUT VALUES *

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

ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) AREA (IN)

------- ------------------------------------------------------------- .750( 1.481) 2 30 244.0 33.0 GROUND( 6.4) 87.0 .0

FIELD AND RESERVOIR HALFLIFE VALUES (DAYS)

--------------------------------------------------------------------

METABOLIC DAY S UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED

(FIELD) RAIN/RUNOFF (RESERVOIR) (RES.

- EFF) (RESER.) (RESER.)

--------------------------------------------------------------------

810.00 2 N/A .00

- .00 ****** 162 0.00

UNTREATED WATER CONC (MICROGRAMS/LITER (PPB)) Ver 1.1.0 JAN 1, 2007

-------------------------------------------------------------------- PEAK DAY (ACUTE) ANNUAL AVERAGE (CHRONIC)

CONCENTRATION CONCENTRATION

----------- ---------------------------------------------------------

95.527 39.962

CILANTRO

Single application @ 1.6 lb ai/acre

RUN No. 31 FOR Prometryn ON Cilantro * INPU

---------------------------------------------------------- RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE %CROP

ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) ARE

---------------------------------------------------------- .600( 1.600) 1 1 244.0 33.0 GROUND( 6.4) 87.

FIELD AND RESERVOIR HALFLIFE VALUES (DAYS)

----------------------------------------------------------

METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC

(FIELD) RAIN/RUNOFF (RESERVOIR) (RES.

- EFF) (RESER.)

----------------------------------------------------------

810.00 2 N/A .00

- .00 ******

UNTREATED WATER CONC (MICROGRAMS/LITER (PPB)) Ver 1.1.0 J

---------------------------------------------------------- PEAK DAY (ACUTE) ANNUAL AVERAGE (CHRONIC)

CONCENTRATION CONCENTRATION

----------------------------------------------------------

103.182 43.161



### 8PARSLEY

A. Single application @ 0.5 lb ai/acre

RUN No. 41 FOR Prometryn ON Parsley * INPUT VALUES *

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

ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) AREA (IN)

-------------------------------------------------------------------- .500( .500) 1 1 244.0 33.0 GROUND( 6.4) 87.0 .0

FIELD AND RESERVOIR HALFLIFE VALUES (DAYS)

--------------------------------------------------------------------

METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED

(FIELD) RAIN/RUNOFF (RESERVOIR) (RES.

- EFF) (RESER. ) (RESER.)

--------------------------------------------------------------------

810.00 2 N/A .00

- .00 ****** 1620.00

UNTREATED WATER CONC (MICROGRAMS/LITER (PPB)) Ver 1.1.0 JAN 1, 2007

----------------------------------- --------------------------------- PEAK DAY (ACUTE) ANNUAL AVERAGE (CHRONIC)

CONCENTRATION CONCENTRATION

--------------------------------------------------------------------

32.244 13.488

B. Two appications @0.5 lb ai/acre, 30 days apart

RUN No. 42 FOR Prometryn ON Parsley * INPUT VALUES *

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

ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) AREA (IN)

-------------------------------------------------------------------- .500( .987) 2 30 244.0 33.0 GROUND( 6.4) 87.0 .0

FIELD AND RESERVOIR HALFLIFE VALUES (DAYS)

------------------------------------------------ --------------------

METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED

(FIELD) RAIN/RUNOFF (RESERVOIR) (RES.

- EFF) (RESER.) (RESER.)

--------------------------------------------------------------------

810.00 2 N/ A .00

- .00 ****** 1620.00

UNTREATED WATER CONC (MICROGRAMS/LITER (PPB)) Ver 1.1.0 JAN 1, 2007

-------------------------------------------------------------------- PEAK DAY (ACUTE) ANNUAL AVERAGE (CHRONIC)

CONCENTRATION CONCENTRATION

--------------------------------------------------------------------

63.685 26.641



### 9C. Three applications @ 0.5 lb ai/acre, 30 days apart

RUN No. 43 FOR Prometryn ON Parsley * INPUT VALUES *

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

ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) AREA (IN)

-------------------------------------------------------------------- .500( 1. 462) 3 30 244.0 33.0 GROUND( 6.4) 87.0 .0

FIELD AND RESERVOIR HALFLIFE VALUES (DAYS)

--------------------------------------------------------------------

METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED

(FIELD) RAIN/R UNOFF (RESERVOIR) (RES.

- EFF) (RESER.) (RESER.)

--------------------------------------------------------------------

810.00 2 N/A .00

- .00 ****** 1620.00

UNTREATED WATER CONC (MICROGRAMS/LITER (PPB)) Ver 1.1.0 JAN 1, 2007

-------------------------------------------------------------------- PEAK DAY (ACUTE) ANNUAL AVERAGE (CHRONIC)

CONCENTRATION CONCENTRATION

--------------------------------------------------------------------

94.342 39.468

C ELERIAC

Single application @ 4 lb ai/acre

RUN No. 51 FOR Prometryn ON Celeriac * INPUT VALUES *

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

ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) AREA (IN)

-------------------------------------------------------------------- 4.000( 4.000) 1 1 244.0 33.0 GROUND( 6.4) 87.0 .0

FIELD AND RESERVOIR HALFLIFE VALUES (DAYS)

----- ---------------------------------------------------------------

METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED

(FIELD) RAIN/RUNOFF (RESERVOIR) (RES.

- EFF) (RESER.) (RESER.)

--------------------------------------------------- -----------------

810.00 2 N/A .00

- .00 ****** 1620.00

UNTREATED WATER CONC (MICROGRAMS/LITER (PPB)) Ver 1.1.0 JAN 1, 2007

-------------------------------------------------------------------- PEAK DAY (ACUTE) ANNUAL AVERAGE (CHRONIC)

CONCENTRATION CONCENTRATION

--------------------------------------------------------------------

257.954 107.903



### 10