The 5 most deadliest poisons in the world | Everyday Science
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The 5 deadliest poisons in the world


What are the Deadliest poisons? A poison is defined as a liquid, solid or gaseous substance that when in contact with a living being causes a disease, an injury, or an alteration of functions that can cause death.

The most potent poison in the world is botulinum toxin, also known as botox. A dose of 100 nanograms can kill a person weighing 70 kilos.

How is the potency of poison calculated?

All substances are potentially toxic at high doses, including water, but the term poison is often used to refer to harmful substances at relatively low doses.

The level of toxicity of poison is measured through the lethal dose 50% LD50, defined as the dose causing death in half of the population.

The 5 deadliest poisons in the world

The LD50 is usually expressed in the amount of poison per kilogram of body weight. The higher the LD50, the more poison it takes to cause death. Therefore, the higher the LD50, the lower the potency of the poison.

The route of exposure is very important to determine the LD50. For example, tetrodotoxin or TTX, the neurotoxin of pufferfish, has an LD50 of 300 µg per kg of weight if ingested and only 10 µg intravenously.

The different routes of exposure, the wide variability of response from one person to another, and the inability to do controlled studies, for obvious safety reasons, makes determining the LD50 a difficult task, so it is not possible to make an exact list of the deadliest poisons in the world.


The 5 deadliest poisons in the world

Cyanide is one of the most common poisons in history and the most popularly known, but its potency is rather low because of its oral LD50 of 6 mg per kg.

Here is a selection of the five deadliest poisons in the world, all of them were several hundred times more venous than cyanide:

  • Botulinum toxin        
  • Maitotoxin
  • Batracotoxin
  • VX
  • Ricin

1. Botulinum toxin

The botulinum toxin, Botox is a neurotoxin produced by the anaerobic bacterium Clostridium botulinum. Botulinum toxin produces the disease known as botulism that can kill by respiratory paralysis.

Botox is widely considered the most deadly poison in the world. Its LD50 is only one nanogram per kilogram of body weight. 100 ng (0.0000001 g) are enough to kill a 70 kg person.

This toxin was discovered in the 18th century in Germany as food contamination. It produces progressive paralysis by blocking the release of the neurotransmitter acetylcholine, a mediator in muscle contraction Death occurs by asphyxiation as a consequence of diaphragm paralysis.

Fact: Botox, at the lowest estimates, costs around: $1,500,000,000/gram. So 100 grams of Botox would be equal to the cost of the ISS. It would also be enough toxin, if administered individually, to kill 1/4 of the world’s population. (source: theguradian)

2. Maitotoxin

Maitotoxin is produced by the unicellular organism alga r Gambierdiscus toxicus, a kind of marine dinoflagellate. Poisoning by fish contaminated with this species of algae produces the disease known as ciguatera, endemic to tropical and subtropical areas, especially in coral reef areas.

Maitotoxin has an LD50 of 50 ng/kg and is probably among the most potent marine poisons.

It produces an increase in the flow of Ca 2+ ions in the heart muscle that can cause its collapse and thereby death. Ciguatera is also produced by toxins from other algae, including ciguatoxin-1, scaritoxin, palytoxin, and okadaic acid.

3. Batracotoxin         

Batracotoxin is an alkaloid produced by several species of frogs of the genera Phyllobates and Dendrobates, and by several species of birds of the genus Pitohui, Ifrita kowaldi and Colluricincla megarhynchos. The frog Phyllobates terribilis produces the most potent batrachotoxin poison.

The LD50 dose of batrachotoxin is 2 µg / kg. The weight of a pair of fine table salt grains can kill a person. Batracotoxin acts by preventing the closure of sodium channels in nerve cells and muscle cells. Death usually comes from cardiac arrest.

4. VX – Nerve Agent

VX (O-ethyl S-2 diisopropylaminoethyl methylphosphonothiolate) is a highly toxic substance of synthetic origin discovered in the 1950s while being investigated with insecticides. It has an LD50 of 3 µg / kg and acts by blocking the action of acetylcholinesterase in neuromuscular synapses. Death is usually due to respiratory paralysis.

VX is considered a chemical weapon classified as a nerve agent. Its manufacture was banned by the Chemical Weapons Convention, signed in 1993 and put into effect in 1997, although NATO and the signatory countries of the Warsaw Pact maintain reservations, at least declared. In 2017, the VX became popular in the media for its involvement in the death of Kim Jong-Nam, brother of North Korean leader Kim Jong-un.

5. Ricin

Ricin is a toxin present in the seeds of castor ( Ricinus communis ). It has a very variable oral LD50, between 1 and 20 mg/kg. The intake of a few seeds is enough to kill a person. By inhalation or intravenously, the LD50 is much lower, around 500 µg / kg.

Ricin belongs to the group of Ribosome Inactivating Proteins. It works by binding to ribosomes and blocking protein synthesis.


Facts About Ricin. Centers for Disease Control and Prevention (United States).

Batrachotoxin by Stephen Wallace. Chemistry World



Handle with care – the world’s five deadliest poisons. The Conversation

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