A disaster is a serious disruption of the functioning of a community. Secondary disasters often occur following the destructive disasters, such as flood, fire, explosion and diffuse of poison gas, etc. Harmful substances enter the body via respire, contamination, food chain.  Toxicology studies the harmful effects of chemical, biological and physical agents in biological systems that establishes the extent of damage in living organisms. Smoke inhalation is the primary cause of death according to fire statistics.  Combustion product may contain unburnt products such as carbon monoxide, hydrogen and even carbon. Carbon monoxide is colorless, odorless, and tasteless, but highly toxic. Carbon monoxide binds to hemoglobin at the same sites as oxygen, but approximately 200 times more tightly. This leads to environmental pollution, disases and deaths.