UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

JAN J 6 2012 

MEMORANDUM 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

SUBJECT: BEAD Chemical Profile for Registration Review: Metribuzin (101101) 

FROM: 

THRU: 

Sunil Ratnayake, Biologist /l !l 

Biological Analysis Branch ( _ IwL N\rJ J;---" 

Rafael 

Science 

Prieto, 

Information 

Environmental 

and Analysis 

Protection 

Branch 

Specialist II L f ~ 

Andrew Lee, Economist 

Economic Analysis Branch 

Biological and Economic Anal 

Arnet Jones, Chief 

Biological Analysis Bran 

Diann Sims, Chief ~.Ji,UA-~'::r""""­

Science Information and Analysis Branch 

" 

Timothy Kiely, Chief ~ \ A A J.. 

Economic Analysis Branch VV'-I'\~ 

Biological and Economic Analy ' Division (7503P) 

TO: Dana Friedman, Chemical Review Manager 

Risk Management and Implementation Branch 2 

Pesticide Re-evaluation Division (7508P) 

p'roduct Review Panel date: January 4, 2012 

INTRODUCTION 

The purpose of this document is to convey usage information and a broad overview of the 

pest management roles of pesticides that are beginning to undergo registration review. The 

anticipated audience consists of the team of EPA staff currently evaluating the registration 

status of Metribuzin, and eventually the general public. This document builds upon the data 

already provided in the "Usage and Label Use Data Packages" that are also provided to 

Registration Review teams by BEAD. The. document is based on information and data 

available to BEAD as of Dec. 21, 2011. 
Metribuzin was fIrst registered in the U.S. in 1973 (USEPA, 1998) and it belongs to the 

herbicide family of triazinones. The herbicides in this family inhibit the photosynthesis of 

susceptible weeds. Metribuzin is widely used for selective control of broadleaf and grassy 

weeds in a wide range of sites including turf grass, vegetables, and fIeld crops. It is applied as 

pre-plant, pre-emergence, post-emergence, and post harvest treatments. Metribuzin can be 

tank mixed with other compatible herbicides to achieve a wider spectrum of weed control. 

USE SITES 

Agricultural Use Sites 

Metribuzin is labeled for use on asparagus, forage and fodder grasses, forage legumes and 

fodder non-grass, fruiting vegetables, grain crops, root and tuber vegetables, seed and pod 

vegetables, and on sugarcane. 

Non-Agricultural Use Sites 

Metribuzin is labeled for use on ornamental lawns and turf, uncultivated non-agricultural 

areas, and other outdoor sites (e.g., airports, athletic fIelds, fencerows, industrial areas, 

lumber yards, military installations, parking areas, rights-of-way, and roadsides). 

COMMON FORMULATIONS AND APPLICATION METHODS 

Metribuzin is formulated as dispersible granules, wettable powder, emulsifIable and flowable 

concentrate. Metribuzin can be applied as pre-plant, pre-emergence, post-emergence, and 

post-harvest treatments. 

USAGE 

Based on private market pesticide usage data, metribuzin's annual agricultural usage 

averaged 1.4 million pounds of active ingredient (A.I.) for 3.8 million acres from 2006-2010. 

From 2006 to 2010, sugarcane (35%), potatoes (25%), soybeans (24%), and alfalfa (9%), 

accounted for the largest percentage of usage in terms of total pounds of active ingredient 

applied. In terms of total acres treated during this same timeframe, soybeans (44%), potatoes 

(23 %), and sugarcane (13 %) accounted for the largest markets. 

From 2006 to 2010, the states with the most agricultural usage in terms of pounds a.i. applied 

were: Louisiana (31 %), Idaho (12%), Washington (8%), and Florida (6%). The states with 

the mos,t total area treated were Louisiana (11 %), Ohio (11 %), Idaho (10%), and Washington 

(9%). 

(Proprietary data, 2006-2010) 

USE TRENDS 

Figure 1 depicts usage trends, in terms of pounds a.i. applied, for metribuzin's top crops. 

Overall, the chart below shows that the use of metribuzin has remained virtually steady from 

1998 through 2010. 

(Proprietary data, 1998-2010) 

2 
Figure 1. Pounds of Metribuzin A lied (1998-2010 on Agricultural Sites. 

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• Soybeans 

• Potatoes 

o Sugarcane 

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II Other 

Other refers to: winter wheat, com, tomatoes, asparagus, dry beans/peas, fallow, fresh/green/sweet 

peas, pasture land, carrots, watermelons, sunflowers, barley, peppers, spring wheat, cabbage, 

snap/bush/ pole/string beans, strawberries, apples, wine grapes, squash, sweet corn, pasture/range, 

and pumpkins. 

Source: Proprietary Data, 1998-2010. 

Figure 2. Total Pounds of Metribuzin Applied (1998-2010). 

2,500,000 ,--------------------------------------------------------------

o = 

= = ..... .... 

o 

..... = 

Source: Proprietary Data, 1998-2010. 

3 

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8 

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00 

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Figure 3. Pounds metribuzin on sugarcane and soybeans. 

1,250,000 

- Soybeans 

- Sugarcane 

- Other 

Of)Cb 0)0)0) ~f;J~ ~~ ..... ~~'), ~~'? ~~ ~~<-, ~do ~&- ~~Cb ~~O) ~ ..... ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 

Year 

Other refers to: potatoes, alfalfa, winter wheat, com, tomatoes, asparagus, dry beans/peas, fallow, 

fresh/green/sweet peas, pasture land, carrots, watermelons, sunflowers, barley, peppers, spring wheat, 

cabbage, snap/bush/ pole/string beans, strawberries, apples, wine grapes, squash, sweet com, 

pasture/range, and pumpkins. . 

Source: Proprietary Data, 1998-2010. 

Table 1. Metribuzin Usage on Non-Agricultural Sites (Pounds A.I.) 

1999 2002 2004 2006 

Golf Courses 1,834 13,042 1,553 3,044 

Institutional Turf 7,700 19 NA 42 

Lawn Care Operators NA 1,329 NA NA 

TOTAL (Ibs. a.i.) 9,534 14,390 1,553 3,086 

NA = not available 

Source: Kline & Co., Inc. 1999,2002,2004, and 2006.