A threat to Homeland Security is the distribution or release of toxic materials (e.g., toxic industrial chemicals) as a means to disrupt society and affect the general health of the population. If additionally these toxic materials have a low vapor pressure, they are hard to detect with traditional chemical point detectors. To thwart this threat, the chemicals are being classified into threat categories, scientific data collected on chemical signatures, technologies suitable as detector technologies identified, and recommendations made for future research and development