1. Botulinum toxin. Scientists differ about the relative toxicities of substances, but they seem to agree that botulinum toxin, produced by anaerobic bacteria, is the most toxic substance known. Its LD50 is tiny – at most 1 nanogram per kilogram can kill a human.
Pål Stenmark regards botulinum toxin – the world's most dangerous poison – as a set of building blocks he can redesign and give new functions. One aim is to produce new and more effective pharmaceuticals, including pain treatments.
Castor Bean (Ricinus communis)
It only takes one or two seeds to kill a child and up to eight to kill an adult. Ricin works by inhibiting the synthesis of proteins within cells and can cause severe vomiting, diarrhea, seizures, and even death.
Cyanide is one of the most rapidly lethal poisons known to man. Cyanide can lead to death in a few minutes to a few hours; therefore, rapid treatment is needed in these patients.
Arsenic is known to be the most potent poison that has killed many lives. It has been used since ancient time and has a long and diverse history of use. Its lack of colou r, smell, and taste made it one of the most preferred poisons.
Thallium is tasteless and odorless and has been used by murderers as a difficult to detect poison. It is found in trace amounts in the earth's crust.
Arsenic has been called the “King of Poisons”, because it had been used to poison royalty and thus alter who would ascend to the throne. The development of the Marsh test, by James Marsh in 1830s, a simple analytical method to detect arsenic, may be a reason why intentional arsenic poisonings decreased.
Carbon monoxide (CO) is a gas that can kill you quickly. It is called the “silent killer” because it is colorless, odorless, tasteless and non- irritating. If the early signs of CO poisoning are ignored, a person may lose consciousness and be unable to escape the danger.
Death from ricin poisoning can take place within 36 to 72 hours of exposure, depending on the route of exposure (inhalation, ingestion, or injection) and the dose received.
Polonium: Polonium is a radioactive poison, a slow killer with no cure.
Blue death is extremely poisonous and can be fatal to humans. If you have not experience any effects then I doubt if you will start now.
Exposure to a large amount of cyanide by any route (breathing, absorbing through skin, eating, or drinking), may cause other health effects as well: Coma. Death. High or low blood pressure.
Botulinum neurotoxins (BoNTs) are the most poisonous substances known to humans, with a median lethal dose (LD50) of approximately 1 ng per kg of body weight [1] and are the cause of the life-threatening neuroparalytic disease botulism [2].
Both are highly toxic/poisonous substances. Arsenic rivals cyanide in both lethality and infamy.
The US has not manufactured thallium since 1984. It has been called the "poisoner's poison" since it is colorless, odorless and tasteless; its slow-acting, painful and wide-ranging symptoms are often suggestive of a host of other illnesses and conditions.
Cyanides can be produced by certain bacteria, fungi and algae. Cyanides are also found in cigarette smoke, in vehicle exhaust, and in foods such as spinach, bamboo shoots, almonds, lima beans, fruit pits and tapioca.
Slow poison is a type of poisoning that occurs over an extended period of time and may take days, weeks, or even months for the symptoms to manifest. Types of slow poisons include heavy metals such as lead and arsenic, certain plant chemicals such as nicotine and caffeine, and chemical compounds made in laboratories.
Injection: Injection of a lethal amount of ricin first causes the muscles and lymph nodes near the injection site to fail. Eventually, the liver, kidneys and spleen stop working and there is massive bleeding from the stomach and intestines, resulting in death from multiple organ failure.
The heart-stopping mechanism of digoxin
Irregular heart rhythm and eventually heart-attack is what makes digoxin poisoning so dangerous. When digoxin enters the body, it binds a transport protein called the sodium-potassium pump situated on heart cells.
Extreme exposure usually leads to unconsciousness, convulsions, cardiorespiratory failure, coma, and eventually death. Too often, death from CO poisoning results with the victim simply falling asleep and never regaining consciousness.
Aconitine: Queen of Poisons.
Strychnine poisoning can be fatal to humans and other animals and can occur by inhalation, swallowing or absorption through eyes or mouth. It produces some of the most dramatic and painful symptoms of any known toxic reaction, making it quite noticeable and a common choice for assassinations and poison attacks.
Prominent examples include cinnabar (a mercury compound), aconite (a highly poisonous herb), bezoar (ox gallstones), and cannabis. Poisons were thus an integral part of healing in ancient China.