Page 1 of 3 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON D.C., 20460

VIA E

- Mail OFFICE OF CHEMICAL SAFETY

AND POLLUTION PREVENTION

December 6

, 2011

Bruce K. Bernard, Ph.D. Tetrachlorvinphos Task Force SRA International, Inc. 5235 Ragge d Point Road Cambridge, MD 21613

- 3518

Subject: EPA Review and Response to Second T ime E xtension Request for submission of required data from the Tetrachlorvinphos Registration Review Generic Data Call

- In (RR

083702

- 28236)

Dear Dr

. Bernard :

The Enviro nmental Protection Agency (EPA or Agency) received the T etrachlorvinphos

Task Force’s (TCVP TF ) 90

- day response to the TCVP registration review generic data call

- in ( GDCI

- RR

- 083702

- 28236 ) on April 15, 2010

. In its 90

- day response the TCVP TF indicated

tha t data would be generated to satisfy both the immunotoxicity ( GLN 870.7800 ) and UV absorption ( GLN 870.7050 ) GDCI data requirements and that an agreement to share the cost to develop the se data existed between one or more registrants.

Also in the 90

- day response, t he TCVP TF requested data waiver s for the following seven studies : hydrolysis ( GLN 835.2120), vascular aquatic plant ( GLN 850.4400), daphnid chronic toxicity ( GLN 850. 1300 ) , fish early

- life stage toxicity ( GLN 850.1400 )

, seedling emergence ( GLN 850.4100 )

, vegetative vigor ( GLN 850.4150 )

, and algal toxicity ( GLN 850. 5400 )

. The Agency denied the waiver requests for these data in a letter to the TCVP TF dated September 8,

2010.

Subsequent to the Agency’s data waiver request denial s ( September 8, 2010 ), the Agency

received time extension requests o n December 21, 2010 ( the TCVP TF submitted seven separate time extension requests) and February 14, 2011 (the TCVP TF submitted a single time extensionPage 2 of 3 request for nine data requirements

, inclusive of those requested on December 21, 2010), which the Agency granted until November 2, 2011

.

On October 20, 2011, the Agency received a second registration review GDCI time extension request for thirteen studies listed below (in T able 1)

. T he TCVP TF indic ated that it was not in a position to financially commit and authorize l aboratories to start the generic DCI studies until the TCVP tolerances had been reinstated on September 16, 2011 . As a result the

Task Force requested additional time to submit the re quired data and proposed several due dates

.

The Agency has completed its review of the TCVP TF’s (10/20/2011) time

- extension request for thirteen studies and has concluded that the TCVP TF’s rationale and proposed

timeframes for conducting these data are adequate jus tification for a time extension

. Therefore, the Agency will grant a time extension for submission of these thirteen data requirements.

However, due to multiple waiver and time extension requests

, with the latter being

submitted just prior to a previously extended due date , the Agency is requiring that the TCVP TF submit interim progress reports

. Therefore , the TCVP TF is required to submit to the Agency a progress report which includes the name of the laboratory conducting the study, curre nt status of

the study, justification for any further delays and anticipated submission date of the final report for each data requirement as a contingency of the Agency’s approval of this time extension.

During its review of the TCVP TF time extension re quest, t he Agency also identified two errors, where

- in the TCVP TF indicated that the t errestrial field dissipation and aquatic field dissipation independent laboratory validation (ILV) method s were due by December 29, 2012.

These data are in fact due to be submitted to the Agency by December 29, 2011. However, based on the rationale and timeframes provided in the TCVP TF’s time extension request, the Agency has determined that an extension of the due dates for these data would be acceptable. As a result

, the Agency is extending the due date for the ILV methods from December 29, 2011 to May 30

, 2012 and is requesting that the TCVP TF submit a current progress report for these data by February 29, 2012 (T able 1)

.

I n regards to the thirteen data requiremen ts which the TCVP TF submitted a time

- extension request, the Agency has grouped these requirements as indicated below . T he first subset of nine data requirements are due by March 30, 2012 and require the submission of recent progress report by January 31, 2012 . The remaining four data requir ements (also provided below in T able 1) are due by September 15, 2012 and require the submission of a current progress report by April 15, 2012

.

Table 1. Progress Report Schedule and Extended TCVP Reg. Review DCI Du e Dates Progress Report Due January 31, 2012 &

Due Date Extended to March 30, 2012

850.1300

- Aquatic invertebrate life cycle (freshwater)

850.1400

- Fish early

- life stage (freshwater)

850.4100

- Terrestrial plant toxicity, Seedling emergen ce (Tier II)

850.4150

- Terrestrial plant toxicity, vegetative vigor (Tier II)

850.4400

- Aquatic plant growth (aquatic vascular plant toxicity, Tier II)