Ricin is a dangerous poison that occurs naturally in castor beans. Accidental exposure to ricin is unlikely, except through the ingestion of whole castor beans. Ricin poisoning is not contagious.​​

Last updated: 19 September 2016

What is ricin?

Ricin is a poison that occurs naturally in the castor bean plant which is used to make castor oil. Castor oil is produced by pressing ripe seeds that have had their outer covering (hull) removed. Heating during the oil extraction process inactivates ricin.

Ricin works by preventing the body’s cells from making the proteins they need. Without these proteins, cells die and death may occur.

What are the symptoms?

The onset of symptoms and the severity of the illness caused by ricin poisoning depend on the route of exposure and the dose received.

Small doses may take 1-2 days to cause symptoms, while large doses can cause severe symptoms within hours.


When ricin is inhaled, symptoms usually develop within 8 hours and are likely to include respiratory distress (difficulty breathing), fever, cough, nausea, heavy sweating and tightness in the chest.

Severe hypotension (very low blood pressure) and respiratory failure may occur, leading to death.


When ricin is swallowed, symptoms usually develop in less than 6 hours, typically vomiting and diarrhoea which may become bloody.

Severe dehydration and hypotension may result. Other symptoms may include hallucinations, seizures, and blood in the urine.

Skin and eye exposure

Ricin is unlikely to be absorbed through intact skin but contact with ricin powders or products may cause local redness and pain of the skin and the eyes.


There is at least one report of a person being deliberately injected with a ricin pellet, resulting in their death.

How is it spread?

Ricin is a poison that is not spread from person to person. Accidental exposure to ricin is highly unlikely, except through the ingestion of castor beans.

If ricin was prepared for deliberate release it might be produced in the form of a powder, a mist or liquid for spraying, or as a pellet.

Who is at risk?

Everyone is assumed to be at risk if exposed to ricin.

How is it prevented?

Accidental exposure to ricin can be avoided by careful handling of castor bean plants and avoiding ingestion.

There is currently no vaccine or prophylactic antitoxin that protects against ricin.

People who have been exposed to ricin may need to go through a decontamination process.

All response personnel entering a potentially exposed environment or managing exposed patients prior to or during their decontamination need to wear appropriate personal protective equipment (PPE).

Ricin can be inactivated by heating above 80 degrees centigrade.

How is it diagnosed?

In cases of known exposure to ricin, people having respiratory symptoms that started within 12 hours of inhaling ricin should seek medical care.

How is it treated?

There is no specific antidote for ricin poisoning. Treatment is supportive and varies with the route of ingestion. Artificial ventilation and treatment of pulmonary oedema may be required following inhalation. Gastric decontamination may be appropriate following ingestion.

What is the public health response?

NSW Fire and Rescue would coordinate the decontamination of people who have been exposed to ricin.

NSW Police would be responsible for any investigation into the possible deliberate release of ricin.

Public health officials may be asked to assist in the investigation and in the monitoring of individuals potentially exposed to ricin.

Additional resources

Australian Institute for Disaster Resilience - Emergency Management Australia (EMA) Manual Series: Manual 13 - Health Aspects of Chemical, Biological and Radiological Hazards (Ricin: pages 255-256).

For further information please call your local Public Health Unit on 1300 066 055.