Vista Engineering Technologies will develop, demonstrate, and commercialize a novel tracer technology to rapidly detect and quantify the concentration of active and inactive CWA/BWA in a building following an attack. One or more interactive and conservative tracers are introduced into a room or the ductwork in a building, and the relative concentration of the sampled interactive and conservative tracers are used to detect and quantify agents present in the rooms, hallways, stairwells, and ductwork of the building. The technology will be faster and more accurate than the current state-of-the art approaches. First, the tracer gases will attain better and more complete coverage. The technology has the potential for interrogating the entire building, an entire floor, or an entire room from a single location, including the furniture, shelving/cabinets, and difficult-to-access areas. Second, the technology has an SNR advantage over other technologies (perhaps, 30 dB), because the noise is controlled, and the interactive tracer, not the threat agent itself, needs to be detected. The technology can be implemented as a contact sensor, a point sensor, and a remote sensor with standoff distances of the dimensions of a room, a floor, or the entire building