UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WAS HINGTON. D.C. 20460

JAN 20 2011

OFFICEOF CHEMICAL SAFETY

AND POLL UTION PREVENTION

MEMORANDUM

SUBJECT: BEAD Chemical Profile for Registration Review: DCPA (07870I)

FROM:

THRU:

Sunil Ratnayake, Botanist /\ ()

Biological Analysis Branch \. t ¥\..\

Katherine Stebbins, Biologist . '(1.:f:f-l iu.-5Iztt;,,,j)

Science Information and Analysis Branch

Michelle Ranville, Economist Li1 ~) Economic Analysis Branch -

Biological and Economic Analysis Division (7503P)

Arnet Jones, Chief

Biological Analysis Branc

Diann Sims, Chief

Science Information and Analysis Branch

Timothy Kiely, Chief . \AA )

Economic Analysis Branch (

Biological and Economic AnSJ:ision (7503P)

TO: Jill Bloom, Chemical Review Manager

Risk Management and Implementation Division Branch 2

Pesticide Re-Evaluation Division (7508P)

Peer Review Panel da te: December 1, 2010

INTRODUCTI ON

The purpose ofthis document is to convey usage Information and a broad overview ofthe pest

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

anticipated audience consists ofthe team of EPA staff currently evaluating the registration status
of DCPA (Dimethyl tetrachloroterephthalate) 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 December 1,2010.

DCPA belongs to the chemical family of chlorinated benzoic acids. The mode of action ofthis

herbicide appears to be inhibition of the normal cell division of root tips of a wide spectrum of

plants (EPA, 1988). Trade names for products containing DCPA include DAC 893, Dacthal, and

Dacthalor. DCPA controls many annual grasses and broadleafweeds in agronomic crops,

ornamental plantings, onions, cole crops, other vegetable crops, ornamental turf and lawns.

COMMON FORMULATIONS AND APPLICATION METHODS

DCPA is formulated as a flowable concentrate, wettable powder, or granular formulation.

DCPA may be applied via broadcast (aerial or ground) spray, chemigation, band treatment, and

soil injection treatment. Various types of equipment may be used including broadcast spray

equipment, spreader, shaker-can, sprinkler irrigation, and soil injection equipment. It is applied

as pre-emergence, post-plant, post-transplant or as a layby treatment (EPA, 1988).

USAGE (Agriculture)

Based on private market survey data from 1998-2008, agricultural usage averaged approximately

500,000 pounds for 100,000 acres (Of!( Kynetec, 1998-2008). In general, DCPA is typically

applied at a rate of 4-6 pounds A.1. per acre (OIK Kynetec, 1998-2008).

From 1998-2008, the largest markets in terms of total pounds of active ingredient applied were:

broccoli, onions, cauliflower, cabbage, and tomatoes (Figure 1). These crops also ranked

similarly in terms of the total area treated.

Figure 1. Major Agricultural Markets for DCPA (percent of pounds A.1. applied)

Cabbage

5"1" Cauliflower

9%

Tomatoes

2%

Oth er crops

5%

• BroccoliC Ontonstr Cauliflowertl Cabbage- Tometoesu Other crop

Source: GfK Kynetec. 1998-2008

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The states with the most agricultural usage in terms of pound s AI applied are: California,

Washington, Arizona, Texas and Oregon (Figure 2). These states also ranked similarly in terms

of the total area treated.

Figure 2. States with Highest DCPA Use- Percent of Total Lbs AI Applied

WA

TX OR

AZ 3% 3%

All others

6%

Source: GIK Kynetcc, [998-2008

USE TRENDS

I _ CA _ WA 0 AZ 0 TX _ OR iii AUothers I

The historical usage data provided in this section is provided for preliminary scoping purposes

only, to convey a broad overview ofDCPA at the beginning of the registration review proce ss.

Non-Ag Usage

In 2000, approximately I million pounds ofDCPA was used by consumers using lawn herbicide

products and an additional 1.8 million pound s was from combination herbicide/fertilizer products

(Kline and Co. Inc., 2001). Usage was not reported in the more current reports from 2003 and

2005, however, usage may have been occurring below the reporting thresholds of about 400,000

pounds for the herbicide/fertili zer combination products and 200,000 pounds for the herbicides.

Use ofDCPA in nurseries is low with only 700 pounds reported in 2003 and 2,600 pounds in

2006 (USDA NASS, 2001-2007).

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Agricultural Usage

DCPA usage has been variable over the 1998-2008 time period (Figure 3).

Figure 3. Pounds A.!. Applied (1998-2008)

800.000 ,-- - - - - - - - - - - - - - - - - - - - - - -

o

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008

I_Broccoli . Onions 0 Cauliflower 0 Cabbage . OtherI

Source: GfK K ynetec. 1998-2008

BIOLOGICAL ASPECTS RELEVANT TO DCPA

According to a publication by the University of Guelph, as of December 2009, no weeds were

reported to be resistant to Dacthal herbicide (Univ. ofGuelph, 2009). However, 13 bio-types of

rigid ryegrass (Latium rigidum) have shown some level ofresistance to DCPA (McAlister et aI.,

2009 ).

HISTORY OF BEAD ASSESSMENTS FOR DCPA

BEAD has not conducted any benefits assessments or Section 18 analyses for this chemical.

DATA NEEDS RELEVANT TO BEAD'S FUTURE WORK ON DCPA

Current usage data for non.ag. DCPA uses (lawn herbicides/fertilizers).

REFERE NCES

Dacthal Flowable Herbicide. AMVAC. 4100 E. Washington Blvd. Los Angeles, CA 90023.

USA. http://www.amvacchemica1.comlmedialpdf/products/specimcn labelsJdacthal flowable.pdf. Accessed on Nov . 15,

20 10.

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DCPA (Decthal) Herbicide Profile. 1988. EPA Pesticide Fact Sheet.

http://pmcp.cce.comell.eduJprofileslherb-gromhrcg/dalapon-ethephon/dcpafherb-prof-dcpa.html

Accessed on Nov. 15, 2010

GfK Kynetec. (1998-2008). EPA Proprietary Data.

EPA Section 18 Database. Available at http://cfpub l.epa.gov/oppref/sectionI8/search.cfm

Kline and Co. Inc. (2001). Consumer Markets for Pesticide s and Fertilizers.

McAlister, F. M., J. A. M. Holtum, and S. B. Powles. 1995. Dinitroaniline herbicide resistance in

rigid ryegrass (Lolium rigidum). Weed Sci ence. 43: 55-62.

USDA NASS (2001-2007). Agricultural Chemical Usage-Nursery and Floriculture Summary.

http://usda.mannlib.comeII.eduJusdainassJAgriChernUsNursF10//2000s/2004/AgriChernUsNursF

lo-09-15-2004.pdf. Accessed on Dec. 3, 2010

Univ.ofGuelph. 2009. Weeds Resistant to Herbicides. http://\V\..w.uoguelph.calplant/resistantweeds/assets/resistant weeds herbic ides 2009.pdf. Accessed on Nov. 15, 2010

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