The fire scene can generate a wide array of chemical contaminants which may have either acute or chronic toxic effects.
Contaminants are present during the active fire and some remain as residuals subsequent to the fire.
Building re-occupancy decisions should only be made by persons with knowledge of the potential presence of toxic residuals in the structure. Fire investigations can be facilitated by use of soot characterization analysis to delineate the zones affected by smoke intrusion. Some of the specialized topics of NCC's fire investigations follow.