For first responders who arrive at the scene of a terrorist attack or hazardous material spill, fast identification of dangerous chemicals is crucial in order to neutralize the threat, save lives, and protect the environment. To arm first responders with knowledge, a software tool was recently introduced by the Georgia Institute of Technology, based in Atlanta. Called Chemical Companion, the software operates on Widows CE-based Personal Digital Assistants (PDAs). By using the tool, first responders can enter details about a suspected substances appearance to learn if a hazardous chemical is present. The PDAs screen then outlines the chemicals risks, as well as protective equipment and medical assistance required to combat the hazard. The software currently offers data about 130 common chemicals associated with Hazmat incidents, and information can be added as needed. Development of Chemical Companion was sponsored by the federal governments Technical Support Work Group. The software will be offered at no cost to the military, law-enforcement officers, and firefighters.