Abstract: This invention is geared at attacking the scourge of explosive fires, burns, environmental pollution, or other such hazards associated with the use, transport, and storage of fuels and other hazardous substances, before they occur, including the explosion hazard present in many automotive rear-end collisions. This is achieved by swiftly reacting a “disabler” or “neutralizer” with the hazardous substance, voluntarily or by automation, on the occurrence of predetermined events that position the hazardous substance to threaten a greater than desired risk of harm. According to one of the preferred embodiments of this invention, the formation of combustion vapors in the ullage of fuel tanks is altogether prevented.