UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON. D.C. 20460 

APR 1 7 2014 

MEMORANDUM 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

SUBJECT: BEAD Responses to Public Comments Concerning the Registration Review of 

Dithiopyr from EPA Docket ID No. EPA-HQ-OPP-2013-0750, DP# 418541 

FROM: Cynthia Doucoure, Environmental Protection Specialist (! . ~~ 

Science Information and Analysis Branch 

Biological and Economic Analysis Division (7503P) 

THRU: Diann 

Science 

Sims, 

Information 

Chief ~ 

and Analysis Branch 

TO: Veronica Dutch, Chemical Review Manager 

Risk Management and Implementation Branch V 

Pesticide Re-evaluation Division (7508P) 

Product Review Panel Date: 

Through this memo, BEAD is responding to Dow AgroSciences (DAS) Comments on the U.S. 

EPA's Dithiopyr Registration Review Docket EPA-HQ-OPP-2013-0750. Comments about the 

label data report and general usage data are listed below, followed by BEAD's responses. 

DAS Comments on Dithiopyr BEAD Chemical Profile: 

1. Reference: General Reference to BEAD Chemical Profile Document. 

The Registration Review docket contains the Agency's Biological and Economic 

Analysis Division (BEAD) Chemical Profile, intended to provide pesticide use-related 

information and economic analyses in support of pesticide regulatory activities. As the 

economic, social, and environmental costs and benefits of the use of any pesticide are 

considered in the review process, DAS is providing a benefits document as an Appendix 

to further substantiate value, benefits, and economic impact of dithiopyr. Stakeholder 

input will further help the Agency to understand and validate the importance of dithiopyr 

to the turf care industry, ornamental nurseries, golf courses, and the real estate market. 

A successful Registration Review process for dithiopyr will ensure that this tool for the 

US. turf and ornamental community remains viable and beneficial. 

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BEAD Response: BEAD appreciates the "Dithiopyr Benefits Assessment Review," which 

further clarifies the benefits of dithiopyr in the U.S. 

2. Reference: Common Formulations and Application Methods: Page 2. Paragraph 

1. Document states: Dithiopyr is formulated as emulsifiable, suspension, and 

soluble concentrates, water soluble pouches, granules, and liquids ready-to-use. 

Comment: Primary DAS end use products containing dithiopyr are EW (emulsion in 

water) and granular formulations. These two formulations comprise the majority of 

product sales associated with DAS dithiopyr registrations. EC, SC and WPIWSP 

formulations are also associated with DAS dithiopyr registrations. 

BEAD Response: BEAD appreciates the clarification of the various dithiopyr product 

formulations. 

3. Reference: Use Sites: Page 2. Paragraph 1. Document states: Dithiopyr is labeled for use 

on landscape,fteld and container grown ornamentals located in ornamental gardens, parks, golf 

courses, and residential areas; on nonbearingfruit and nut trees (nonfood producing trees); on 

turf sites (residential and institutional lawns, athletic fields, commercial sod farms, and golf 

course fairways, and roughs); and uncultivated nonagricultural areas including roadsides, 

utility right-of-ways, railways, and industrial areas. 

Comment: Suggested clarifications to " ... container grown ornamentals located in 

nurseries, ornamental gardens ... " and " ... golf C(JIJ]"se tees, greens, fairways, and 

roughs ... ". 

BEAD Response: BEAD appreciates the clarification on the container grown ornamental use 

site of dithiopyr. 

4. Reference: Information That May be Useful for BEAD's Future Work on Dithiopyr: 

Page 5. Paragraph 1. Document states: Obtaining additional information on the 

current use of dithiopyr in uncultivated non-agricultural and industrial sites would 

improve future BEAD assessments and may be required as part of the registration 

review of this pesticide. Information needed regarding the current use of dithiopyr on 

all sites includes the annual pounds of a.i. applied in the U.S., the number of acre 

treatments, typical application rates (single and yearly), and the number of applications 

per year. 

Comment: DAS would cite California Department of Pesticide Regulation use 

reporting data as supportive to this request. Dithiopyr, as an effective pre-emergence 

herbicide, can be a key part of fire risk mitigation on roadsides and rights of way. This 

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herbicide, can be a key part of fire risk mitigation on roadsides and rights of way. This 

is evidenced by the use of dithiopyr in the state of California. CA DPR has 

reported increasing usage of dithiopyr in rights of way growing from 7785 lbs in 2009 

to 11, 732lbs in 2011 [14-16}. 

BEAD Response: BEAD appreciates the CA DPR usage data on use of dithiopyr on rights~ofway. 

DAS Comment on Dithiopyr EFED Label Data and HED Master Label Reports: 

1. Reference: Spreadsheet, Columns I & N 

Comment: A single maximum application rate of0.5 lb a. i./acre exists for all DAS 

registrations containing dithiopyr. Several rows in this document suggest otherwise. 

For example, Row 67 indicates that the maximum application rate for Dimension® Ultra 

SC as 0. 5115 lb/a, while the actual maximum single application rate 0. 2 gallons per 

acre, equivalent to 0.5 lb a. i./acre [17]. DAS respectfully requests that risk assessments 

for DAS registrations are performed using the maximum application rate of0.5 lb 

ail acre. 

References 

Dimension Ultra SC Product Label. EPA Reg. No. 62719-467 

http://www. epa.gov/pesticides/chem search/ppls/062 719-00467-2002050 l .pdf 

BEAD Response: The maximum application rate for the Dimension Ultra SC Product label 

(62719-467) was calculated in BEAD using a density of9.3 lb per gal. BEAD acknowledges that 

the DAS method of calculation for this label has resulted in a slightly different maximum 

application rate. 

This concludes the comments that BEAD received from DAS on the Dithiopyr Registration 

Review Docket. BEAD appreciates the feedback from DAS on the label data report and general 

usage data in the docket. 

Sources: 

C. Doucoure, S. Ratnayake, D. Berwald. 2013. BEAD Chemical Profile for Registration 

Review: Dithiopyr (128994). Office of Pesticide Programs, U.S. Environmental Protection 

Agency 

EFED Label Data Report: Dithiopyr (128994). Office of Pesticide Programs, U.S. 

Environmental Protection Agency 

HED Master Label Report: Dithiopyr (128994). Office of Pesticide Programs, U.S. 

Environmental Protection Agency 

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