Uniformed services personnel run toward situations that others flee. In a world that is increasingly dependent on man-made chemicals, they also face the danger of toxic exposures, whether at an inner-city fire, an illicit drug lab, a battlefield or a freeway chemical spill.

The essence of any emergency is that it is both dangerous and unexpected. Often, first responders do not know in advance what toxic substances they will encounter, or what steps they should take to protect themselves.

Once they are on the scene, their duty is the first priority. Only afterward — sometimes immediately, or sometimes after years of exposures—do they experience the consequences of the toxic assault they have endured.