# t;')t/;J ENVIRONMENTAL PROTE C T I ON AGENCY

WASHINGTO N

, D.C. 20460

OFFICE OF

P R E V EN T I ON, P ES TICI D E S A D

T

O

X

C I S U BSTANCES

August 31,2010



### MEMORANDUM

SUBJECT: Environmental Fate Assessment of Terbutryn for Use in Indoor and

Outdoor Materi a l s Preservatives



### Cas No.: 88 6

- 50

- 0 

### DP Barcode(s): Q.371449



### FROM:

PEER REVIEW:

TO: James Breithaupt, Agronomist

Risk Assessment and Science Supp Branc h ( RASSB )

Antimi c r o b i a l s Division (7 5 1 OP)



### Siroos Mostag h i mi, Ph.D.

- 

# Af,_JJ/

-- ' 1 L

·

R i sk Assessment and Science Support Branch ( RASSB )

Antimicrobial Div i si o n (75 1 OP)



### Nader E l kassabany, C h i ef 

# ¢

R i s k Assessment and Science Su pport Branch ( RASSB )

Antimicrobials Div i s ion (75 1 OP)



### Mark Hartman, Chief

Regulatory Management Branch II

Antimi c r obials Divisi o n (7 5 1 O P )



### Chemical Name

2

- ( tert

- butylamin o )

- 4

- ( ethylamino )

- 6

- ( methylthi o )

- s

- triazine 

### PC C o de

080813 

### CAS#

886

- 50

- 0 

### Common Name

N o ne



### EXECUTIVE SUMMARY

This memorandum contains the environmental fate assessment for the proposed use of

terbutryn ( Troy s a n ® Terbutec) in interior and exterior materials coatings at 0.02

- 0.5% b y

weight. These uses inclu d e joint cements, masonry coatings, paint, roof coatings, sealants,

stuccos, pl a s tics ( v i ny l

, PJB )

, and wood protective stains. No studies were reviewed in this

memorandum because all data were previously reviewed and accepted i n various d o c uments in

t he 198 0 's.2 Test Guideline Result D egradates Comments/Reference

Hydrolysis (1 6 1

- 1,

835.2120) Essentially stable at pH

5, 7, and 9 Not applicable MRIDs 00147480,

00162356

Review dated 12/ I 0/86

Photo d e g rada t io n in

water (161

- 2, 8 3 5.2240) Half

- life of 3 days

Half

- lives of 7.5 hours

(non

- sensitized) and 6.1

-

7.8 hours ( sensitized ) Major degrada t e s :

Deethylated terbutryn

Hydrated terbutryn

(minus thiomethyl )

Hydro x ylated terbutryn

(minus thiomethyl )

Major degrates:

Hydrated terbutryn

(minus thiomethyl )

Deethylated terbutryn MRIDs 00142912,

00162357

Review dated 12/1 0 / 86

P h otodegradation on

soil (161

- 3, 83 5

. 2410) 9 6

- 128 hours Not available MRID 00062358

Review dated 1 2 / I 0/86

Aerobic soil metabolism

( 1 62

- 1

, 835.4100) Half

- l i fe of 67days Major aerobic

degradates:

Deethylated terbutryn

Terbutryn m inus tertiary

butyl MRIDs 00162359

40160301

Reviews dated 1 2 / 1 0 / 86

and II / 23/87

Anaerobic soil

metab o l ism ( 162

- 2,

835.4200) Half

- l ives of 114

- 169

days No major degradates

formed MRIDs 00162359

40160301

R

eviews dated 12/1 0 / 86

and I I /23/87

Aerobic aquatic

metabolism (162

- 4, 835.

4300) Half

- Jives of62 and 35

days for Rhine and Pond

systems, respectively No major degradates

formed

Almost all residues in

water initially, but they

partitioned to sediment. MRID 00161360,

Review dated 1 2 / I 0 / 86

Leaching

- adsorption

desorption ( 163

- 1,

835.1230) Texture Kads Koc

Sand 42 2,380

Lm. Sd. 2.6 1,490 Not applicable MRIDs 0 0 1 42913,

00147483,00147483,

0014785,00162361 ENVIRONMENTAL FATE

Terbutryn is a triazine compound t hat was previously used in row crops. It is essentially sta b l e

t o hydr o l ysis (minimal degradation in 30 days), essen t i a l l y stable to soil and aquatic metabolism

(half

- lives of 3 5

- 169 days), but can degrade rapidly in the presence of light without sha d i ng and

suspended sediment (half

- life of about three days). A ll reported metab o l i tes and degradates

contained an intact triazine ring w i t hout various constituents on the ring. Mobility of terbutryn i n

s o i l was m i nimal with Kacts v a l ues of2.6

- 195 and Koc values of 1,490

- 12,442 ml/g. As expected,

sorption was related to clay and orga n i c matter content because of the lack of po s i t i ve or nega t i ve

e l ectric charges. In the field, the hal f

- lives were 17 days i n Texas and 358 days in Nebraska.

Some movement of parent compound and hydroxylated terb u t ryn occurred to the 12

-

18 inch soil depth. 

### In fish ponds, the half

- lives for parent terbutryn were 7

- 14 days in water and

18

- 64 days for sediment. Table 1 below contains the tabulated study results.

Table 1. Results of Environmental Fate Data for Terbutryn3 S i .L m

. 13 1,513

Clay 195 12,442 Review dated 1 2 / 10/86

Ter r estrial field

dissipation ( 16 4

- 1,

835.6100) Half

- lives of 17 and 358

days in TX and NE,

respectively Some movement of

parent and hydroxylated

terbutryn ( minus

thiomethyl group) into

6

- 18 inch depth in NE MRID 00147486

Review dated 1 2 / 1 0/86

Aquatic field dissipation

(164

- 2, 835.6200) Concentrations of parent

in wat e r were l / 251h of

nominal by 14 days.

Half

- life of7

- I4 days

for water and 18

- 64

days for sediment Terbulethylazine

degradate was lll 6 1 of h

nominal in water by 14

days.

Half

- lives of7

- 14 days

for wat e r and 18

- 56

days for

terbulethylenazine MRID 00038292

Review 8 / 1 0 / 89 On e

l iner database

If there are any questions, p l ease co n t act Jim Breithaupt at 703

- 305

- 5925 or at

br e i thaupt. j ames@ep a

. gov.