Chemical spill emergencies are exacerbated by a lack of information at the scene with which to quickly assess the situation and determine the appropriate protective action. WRI has concluded that the most successful emergency tools (models) for predicting toxic cloud behavior are those that use field test data as part of their development. After analyzing more than 100 real-world chemical spill accidents and field test releases, WRI has also concluded that information from dense gas/toxic models must be communicated in a fast, simple way to emergency responders or it will not be used. In an effort to address this technology gap, WRI has developed PEAC{trademark} (Palmtop Emergency Action for Chemicals). PEAC is an innovative tool that combines hardware, software, data bases developed by WRI and other organizations, and a unique approach to modeling protective action distances tested with actual field data. PEAC brings modeling data and other reference sources together in a single piece of portable equipment to help emergency responders evaluate a chemical spill incident and quickly determine protective action distances.