Document JvxOvq7vrLRy2vQX7dwRY0n12

Odw Chemicals TaskForce 2001 L Street, NW, Suita 506A, Washington, D.C. 20036 202-775-0232; fax 202-833-0381 September 18,1996 To: Jim Barter, PPG Jean Domoradzki, Dow David Goldsmith, Georgia Gulf Bill Hayes, Dow Jim Kniaak, Oxychem James Lewis, Geon Mike Machovech, Oxychem Phil Ostrowski, Oxychem Dave Penny, Vista Mark Swanson, Vulcan John Wilkinson, Vulcan cc: C. Norman, Patton Boggs.LLP D. Kracov, Patton Boggs,LLP From: Peter Voytek Re: Status Report on the 1,1,2.2-Tetrachloroethane 14 Day Gavaqe Study As you already know the 14 day gavage study has been completed and sent to EPA many months ago. However, in August I was contacted by Bruce Mintz and Kris Khana (two of the toxicologists in the Water Office responsible for reviewing the study for the Agency) to address some questions concerning the raw data and interpretations of the results. I met with them for about 3 hours and discussed the study in great detail. The meeting went very well. I was able to answer their questions and they were satisfied that they could use the study to establish a short-term advisory value. I was able to obtain some pharmacokinetic constants for 1,1,2,2tetrachloroethane from Mike Gargas in order to derive a PBPK model. I spoke with Jim Bruckner, the senior investigator of the study, who has additional metabolic parameters that can be used to refine the model. W both agreed that the study results combined with the PBPK model is worthy of publication in a peer reviewed journal. For example, preliminary simulations with the crude mod I show that peak brain concentrations of DO CONF TDFNTTAt 1,1,2,2-tetrachloroethane are about 10 fold higher via gavage versus the same dose given in drinking water over a twenty-four hour period. This indicates that the gavage route is likely to overestimate the neurotoxicity of tetrachloroethane. Both Bruce and Kris are very interested in exploring the use of PBPK modeling to better estimate potential hazards of drinking water contaminants. I will be meeting with them in the future to show them the tetra- simulations. In summation, the ODW Chemicals Task Force has met its goals and in doing so established a good working relationship with the EPA Drinking Water Office. Attached is a final statement that shows the balance of the collected funds. I asked Jim Barter to request the Task Force for one last expenditure of 5 thousand dollars to cover the preparation of the manuscript and publication costs. Thanks for your participation. If you have any questions please give me a call. DO T ?S?bb CONFTDFNT TAl