The Department of Homeland Security’s Science and Technology (S&T) Directorate, Chemical Security Analysis Center, has reposted a Request for Information seeking sources to execute a gap analysis for atmospheric transport and dispersion modeling of large-scale toxic chemical releases. There is concern and evidence that current modeling and consequence assessment approaches are inadequate at addressing large-scale releases of some toxic chemicals. The gap analysis will involve a comprehensive evaluation of the current state of knowledge surrounding the release and computer modeling of toxic inhalation hazard materials from large transportation containers. Sol. No. Repost-RFI-ST-TD-09- 01. Respond by Jan. 7. Contact: Timothy Davis, contracting officer, 202-254-5676, [email protected].