ABSTRACT
Carbon monoxide (CO) is a by-product of incomplete oxidation or combustion of carbonaceous materials. Poisoning from CO can occur due to accidental or intentional causes. Due to high affinity of this poison to heme, it produces many hypoxic and non-hypoxic effects. Cherry red hypostasis is a characteristic feature. Carbon dioxide is another asphyxiant which is also a normal constituent of air. It has direct toxicological effect that causes asphyxiation and at high concentration produces narcosis. Diagnosis in postmortem is possible only after circumstantial consideration and ruling out other causes of death. Hydrogen cyanide is potentially a deadly and rapidly acting chemical asphyxiant causing painless and quick death. It has peculiar bitter almond odor and is a cytotoxic poison. Acute intoxication can present with manifestations affect central nervous system, cardiovascular system, respiratory system, cutaneous and gastrointestinal system. Chronic poisoning is encountered in some occupational exposures. Cyanide pills also referred as suicide pills and are used to avoid torture on getting arrested. Sewer gas is a complex mixture of many toxic gases produced from decaying of industrial or domestic waste. Hydrogen sulfide is one of them which is also called as knock down gas and causes histotoxic hypoxemia.
