It can be in the form of a powder, a mist, or a pellet, or it can be dissolved in water or weak acid.
It is a stable substance. For example, it is not affected much by extreme conditions such as very hot or very cold temperatures.
Ricin has some potential medical uses, such as bone marrow transplants and cancer treatment (to kill cancer cells). How you could be exposed to ricin
It would take a deliberate act to make ricin and use it to poison people. Accidental exposure to ricin is highly unlikely.
People can breathe in ricin mist or powder and be poisoned. Ricin can also get into water or food and then be swallowed.
Pellets of ricin, or ricin dissolved in a liquid, can be injected into peoples bodies.
Depending on the route of exposure (such as injection), as little as 500 micrograms of ricin could be enough to kill an adult. A 500-microgram dose of ricin would be about the size of the head of a pin. A much greater amount would be needed to kill people if the ricin were inhaled (breathed in) or swallowed.
In 1978, Georgi Markov, a Bulgarian writer and journalist who was living in London, died after he was attacked by a man with an umbrella. The umbrella had been rigged to inject a poison ricin pellet under Markovs skin.
Some reports have indicated that ricin may have been used in the Iran-Iraq war during the 1980s and that quantities of ricin were found in Al Qaeda caves in Afghanistan. Ricin poisoning is not contagious. It cannot be spread from person to person through casual contact.