View Full Version : Ricin

02-02-2004, 22:18
Ricin is a toxalbumin extracted from the beans of the castor oil plant. It inhibits protein synthesis causing cell death.

. Accidental poisoning with ricin has occurred following ingestion of castor oil seeds. Although ricin is poorly absorbed following ingestion, one to three beans chewed by a child, or as few as eight seeds chewed by an adult may be fatal.

. Ricin has been considered as a potential chemical warfare agent. Although non-volatile, aerosols may be inhaled.

. Ricin is particularly toxic if injected. The fatal dose by injection is
thought to be around one microgram per kilogram body weight.

Summary of Human Toxicology

. Onset of symptoms may be delayed after absorption via any route. Fever is common. Death may be due to multi-organ failure.

. Ingestion typically causes irritation of the oropharynx and oesophagus, and gastroenteritis.

. Irritation and conjunctivitis may occur. Miosis, mydriasis and optic nerve damage have been reported.

. Bloody diarrhoea, vomiting and abdominal pain.

. Pulmonary oedema, pneumonia and ARDS.

. Seizures and CNS depression.

. Fluid loss may cause tachycardia.

. Allergic responses have been reported following exposure to castor oil beans.

. Abnormal liver function tests, including raised transaminases occur.

. Haematuria, proteinuria and elevated creatinine.

Personnel must not enter a contaminated area without full personal protective equipment including respiratory protection.


. Primary (first look) triage should be carried out using the standard triage sieve. As symptoms may be delayed few additional discriminating factors are likely to be present.

Mass Decontamination

. Patients should be removed from the source of exposure. All the patients' clothing and personal effects should be removed. Skin decontamination should be carried out using a rinse-wipe-rinse regime with dilute detergent (10ml washing up liquid to a 10 litre bucket of water).

. Contaminated clothing should be placed in clear, labelled, sealed bags to prevent further contamination

. Casualties should subsequently don clean clothing e.g. paper suits.

. If eyes are exposed, remove contact lenses and irrigate thoroughly with running water or saline for 15 minutes.

. Casualties exposed only via ingestion do not require whole body


. Treatment is symptomatic and supportive. No antidote is available for the treatment of ricin poisoning.

. Allergic reactions should be treated conventionally.

Hospital Admission Criteria

. Symptomatic patients should be admitted.

. Patients who are thought to have ingested ricin should be admitted for observation.

. Patients who are thought to have ingested ricin and remain asymptomatic after eight hours may be discharged.

. Patients who are thought to have been exposed by aerosol should be admitted for observation, even if asymptomatic.

. Patients who are thought to have been exposed by aerosol and remain asymptomatic after 24 hours should be discharged.

Doc T
02-02-2004, 23:04
thanx NDD...

unfortunately this is fast becoming stuff we all need to know.

doc t.

02-02-2004, 23:17
Originally posted by Doc T
thanx NDD...

unfortunately this is fast becoming stuff we all need to know.

doc t. Add my thanks:

Unfortunately, is the operative word here:


02-07-2004, 08:14
hello there... been out for a few days... thanks for the ricin info. one more piece of info i need.... how long after exposure (ingestion, inhalation) should we look for symptoms?? i got the discharge criteria but how about a bit more specificity for initial onset.

02-07-2004, 09:52
The time from exposure to ricin toxin to onset of symptoms can range from less than 1 hour to 12 hours or greater. Symptoms of poisoning from eating ricin-contaminated food or Castor beans can occur within 2-3 hours. Inhalation of ricin-contaminated particles can cause symptoms within 3 hours.

05-21-2010, 06:05
I apologize for the necro-post here. I was at a talk with a Texas research lab that primarily focuses on Ricin - vaccination and use of the toxin as a therapeutic. Interesting and scary stuff. The village idiot can make this stuff and there are an estimated 50 million tons of it as a byproduct of producing castor oil - this supply is large unaccounted for.

The reports from the lead investigator state the fatal dose is:
3-5 micrograms per kilo if inhaled
5-7 micrograms per kilo if injected
20 micrograms per kilo if ingested, but much smaller doses (5 micrograms per kilo) are fatal if taken on an empty stomach

There are 2 active sites on the compound - the primary, as NDD states above, which inhibits protein synthesis at the ribosomal level. The secondary MOA is by causing vascular leak by a separate binding site which interacts with vascular endothelium. Symptoms in the first 6-12 hours are primarily secondary to vascular leak; the protein synthesis toxicity is seen after. Ricin is typically lethal within 72 hours if a lethal dose is received. The first post in this thread covers a vast majority of the symptoms and intervention.

The investigator has headed up the efforts to produce a Ricin vaccine which has had excellent success in animal models and in passive immunity conveyed to mice from vaccinated humans. It protects against both aerosolized and ingested Ricin; injected has not been tested as it is an unlikely route of administration as a weapon, although it has been theorized that it conveys protection against injection as well. The vaccine is stored as a lyophilized compound that is stable for room temperature for years (2 thus far, ongoing studies continue). The original form was intramuscular but it looks like the intradermal injection may be more efficacious and easier to administer.

Further human studies are underway but getting funding for this project has been difficult since January 2009. Unfortunately, with the change of administration, Obama has made this a low priority and is not looking to produce the vaccine, although they say they may have some produced for the national stockpile.

05-21-2010, 09:44
The castor bean plant grows like a weed in southern California. Any person with a creative mind and a little effort (terrorist) could use the beans to devestating effect. If I am correct, pure Ricin, which is not that hard to produce, is considerably more lethal than Cyanide.

05-21-2010, 10:24
Ricin is lethal and significantly lower doses, but Cyanide kills more quickly.

05-22-2010, 09:17
Ricin was the agent used by the KGB to kill Georgi Markov using an umbrella tip to inject an almost microscopic dose of Ricin into his leg...

05-22-2010, 11:35
Ricin was the agent used by the KGB to kill Georgi Markov using an umbrella tip to inject an almost microscopic dose of Ricin into his leg...

Actually...used by the Bulgarian secret police, Darzhavna Sigurnost (Bulgarian: Държавна сигурност). ;)


05-22-2010, 12:37
...With the aid of the KGB acording to the article I read. 2 other attempts had been made on Markov's life by the Bulgarians. Markov was a Bulgarian defector who made broadcasts into Iron Curtain countries for Radio Free America and the British equivalent. He also was an author, critical of the Commies....Not a nice way to die