The Nebulized Airborne Biohazard Stage Alert (NABSA) is a method utilizing an optical particle counter in conjunction with a fluorometer as triggers to detect and assess potential biohazard threats infused into surrounding air. In the first stage an optical particle counter is constantly passing sampled air in front of an energy source, in turn scattering light. This scattered light is evaluated to establish if the particles are above one micrometer in concentrations, and thus potentially an aerosolized threat. Such detection triggers the secondary stage in which the sample particles are tested for viability via processing through a dye with fluorescent properties affected when bonded with an entity universally found in all biological substances and a UV light source. The detection of concentrations of oversized, viable particles triggers the third stage to compare a sample of the particles to known biowarfare agents to delineate the specific agent species.