Abstract: A system and method for determining hazard levels of chemical, biological, and nuclear agent in an environment processes chemical vapor concentration measurements and generates hazard levels of the chemical vapor. The system and method provide an estimate of hazard level values by using an exponentially weighted moving integration of the vapor concentrations. When the estimated hazard level values match or exceed empirically predetermined hazard accumulated dosage values for a particular chemical, biological, or nuclear agent, an indication of the level of hazard is generated.