Poison is a chemical that produce a harmful effect on a living organism. Almost any substance has the potential of being poisonous in humans if a substantial amount gains entry into the body or if the substance enter the body by the way of the wrong route. As a result, a variety of poisons exist in solid, liquid, gaseous or vaporous form. Naturally occurring poison are used by poisonous plants and animals to prevent predation or to capture prey. Synthetic poisons range from certain types of pharmaceuticals (used other than as directed) or household cleaning products to waste product of industrial and nuclear energy plants and chemical deliberately used as weapons. Dosage, route of entry, and poetry (strength) determine if a substance is poisonous. For example, if water is accidentally inhaled into the lungs instead of being swallowed, it becomes an asphyxias poison. Whether a specific dose of a prescription drug way be safe effective for a 45-year-old man who weighs 82 kg (180 lb), the