What Is Ricin?
- Ricin is a potent toxin that has gained attention in recent years because it could be used as an agent of biological warfare or as a weapon of mass destruction (WMD). Ricin is derived from the beans of the castor plant (Ricinus communis), and is part of the waste material called "white mash" that is left over from processing castor beans into castor oil.
- Only a small amount of this poison can be lethal. Exposure arises when it is inhaled, ingested, or injected.
- Ricin is a type of poisoning and an infectious disease, and it's not contagious (spread from person to person). Symptoms of ricin poisoning depend upon the amount of the toxin, and the method of exposure, but may include
- Signs and symptoms of ricin poisoning usually begin within 4-6 hours of being exposed to the toxin. Death can occur between 36 and 72 hours of exposure. The resulting symptoms depend upon the amount of the toxin and the method by which the individual was exposed.
- There are no available treatments, antidotes, or vaccines for ricin poisoning.
What Is Ricin Made From and What Is It Used For?
Ricin is a protein derived from the beans of the castor plant (R communis). Castor beans are used in the production of castor oil, a brake and hydraulic fluid constituent. Ricin makes up 3% to 5% of the "waste mash" that is produced during this process. Separating out this protein is not difficult. It only requires chromatography, a common undergraduate chemistry skill.
Ricin is easily and inexpensively produced, highly toxic, and is stable in aerosolized form. The use of this type of poison for terror attacks has been documented in both the US and other countries.
When Do the Symptoms and Signs of Ricin Poisoning Begin?
Symptoms depend on the route of exposure and the amount of absorption. Possible routes of absorption are respiratory (inhaled aerosol), gastrointestinal (GI [ingested]), and injected (percutaneous).
- If exposed through inhaled aerosol, it will most likely affect numerous individuals simultaneously. In this case, a cluster of people would develop similar symptoms over a brief period, typically within 8 hours following inhalation. Such an occurrence would point to the possibility of an intentional act. People exposed to it may experience fever, nausea, and vomiting, a progressively severe cough, and congestion in the nose and the throat. Other symptoms associated with inhalation of ricin include difficulty breathing and tightness in the chest. With significant exposure to the poison, breathing difficulties occur within 12-24 hours. A chest X-ray may reveal excess fluid in the lungs.
- If exposed by ingesting contaminated foods or beverages, symptoms may initially mimic food poisoning, usually within 6 hours after ingestion. People who ingested it may have abdominal pain, often accompanied by vomiting and diarrhea. Because of this, they may also become dehydrated. Although ingesting ricin is usually less toxic than exposure through inhalation, with significant amounts of the poison, which results in more severe symptoms, and possibly death. Dehydration is common. If the dose was sufficient and the disease has progressed, vomiting blood or passing bloody diarrhea or dark-colored tarry stools may occur.
- People injected with ricin, either in pellet form or with it dissolved in a liquid, may experience pain and swelling at the injection site. They may experience other flu-like signs, such as nausea, vomiting, and body aches. More severe symptoms will occur later and a critical life-threatening syndrome will develop. The skin at the injection site is examined for swelling and redness. The affected area may feel painful. The skin is also examined for the possibility of a retained foreign object. The physical findings on the skin may occur prior to or at the time of other flu-like symptoms.
What Should You Do If You Have Been Exposed to Ricin?
If you think you’ve been exposed to ricin you should seek medical care as soon as possible.
- If in an area where it has been released and people may have been exposed to it, it is necessary to immediately leave that area and move to an area with fresh air.
- If near an area where it has been released, wait for emergency personnel to advise provide instructions about appropriate evacuation procedures.
- In an aerosol attack, use protective masks that are effective in preventing toxicity.
- To avoid possible contamination if exposed, remove and dispose of any clothing, and thoroughly wash the skin with copious amounts of soap and water. If the affected individuals' eyes are irritated, the eyes need to be irrigated with water.
What Procedures and Tests Diagnose Ricin Poisoning?
Diagnosing an aerosolized attack or a food and water contamination of this type of poisoning primarily depends on symptoms and the likelihood of such an exposure. In cases of an isolated ricin injection, diagnosis is extremely difficult. In addition, diagnostic testing is of limited value, because there are no definitive, widely available medical tests that can confirm exposure to the poison. Nonetheless, in the case of possible exposure, the patient will most likely undergo a complete physical examination by a doctor. Sophisticated diagnostic tests (not widely available) can identify ricin in the body up to 24 hours after exposure. Please see the section on signs and symptoms for information about early symptoms.
How Much Ricin Can Kill a Person?
A very small amount of ricin is lethal. In fact, it is more potent than cyanide. An amount as small as a grain of table salt can be sufficient to kill an adult if it is ingested, inhaled, or injected. This poison acts by preventing cells from making proteins; if body cells cannot make protein, they eventually die. The person is killed when cells that compose vital organs cease to function.
How Long Does It Take to for a Person to Die from Ricin Poisoning?
A person can die from ricin poisoning by injection in about 36 to 72 hours after exposure. The type of exposure also determines the speed, severity, and type of symptoms that will develop.
Is There an Antidote to Cure Ricin Poisoning?
There is no available antidote or vaccine. Regardless of the route of exposure, treatment remains mainly supportive. If you think that you may have ricin poisoning call 911 or go to the nearest Emergency Department immediately.
If a person has inhaled ricin they may need assistance with breathing. If ricin poisoning is severe, the person who was exposed may require intubation and use of a ventilator. If the person has ingested it, the stomach may need to be pumped (called gastric decontamination). Super-activated charcoal may also be given to help soak up the poison. To treat dehydration, intravenous fluids may be given.
What Drugs Help Ricin Poisoning Symptoms?
Antibiotics serve no role in the treatment of ricin poisoning, as this is not an infectious condition. Medications may be given to treat seizures and low blood pressure that are sometimes associated with exposure to the poison. In the case of ricin exposure by injection, antibiotics may serve to prevent a secondary infection. A tetanus immunization may also be given as a precautionary measure.
Can You Protect Yourself from Being Poisoned by Ricin?
The only effective prevention against a biological attack with ricin is avoidance. Unfortunately, no antidote or vaccine exists. Currently, investigations are ongoing for possible vaccines and ricin inhibitors. Protective masks have been shown to be effective in preventing toxicity during an aerosol attack.
Although ricin is not the ideal biological warfare agent, it remains a threat, primarily as a food and water contaminant. This poison is widely available and easily produced. With the increasing number of biological threats, hoaxes, and "how to" Internet resources available, this threat has the potential to become reality. Therefore, being familiar with its characteristics is important.
What Are the Phone Numbers for Ricin Poisoning?
Local or regional poison control centers may be able to provide more information about ricin. The American Association of Poison Control Centers' telephone number is 1-800-222-1222.
The US Centers for Disease Control and Prevention (CDC) and the Agency for Toxic Substances and Disease Registry (ATSDR) are additional resources for informational material about ricin and its toxic effects.
Has Ricin been Used for Bioterrorism?
Although a large amount of ricin would be necessary to produce many casualties, it would be highly effective within a closed environment. It can be disseminated as an aerosol, by injection, or as a food and water contaminant. Its use as a food and water contaminant is a major concern. If it were used in that fashion, resultant deaths could overwhelm local health-care resources. The classic incident of ricin bioterrorism use (London, 1978) is when an assassin silenced (killed) a dissident Bulgarian writer Geogi Markov by stabbing a ricin-containing substance into his foot with an umbrella tip.
Even use without casualties can be disruptive.
- Three US Senate office buildings closed on February 3, 2004, after ricin was found in the mailroom that serves Senate Majority Leader Bill Frist's office. No injuries were reported.
- On February 4, 2004, as part of the ongoing investigation as to the source of this attack, the Secret Service acknowledged that it had also been found at a White House mail-processing center in early November 2003.
- A vial containing ricin was also found at a post office in Greenville, South Carolina, in October 2003. The envelope, addressed to the US Department of Transportation, was labeled "caution RICIN POISON." The letter, protesting a proposed federal limit on the number of truckers' hours behind the wheel to go into effect in January 2004, was signed "Fallen Angel."
From 1991-1997, three cases involving ricin were reported in the United States.
- In Minnesota, four members of the Patriots Council, an extremist group that held antigovernment and antitax ideals and advocated the overthrow of the US government, were arrested in 1991 for plotting to kill a US marshal with it. The poison was produced in a home laboratory. They planned to mix it with the solvent dimethyl sulfoxide (DMSO), and then smear it on the door handles of the marshal's vehicle. The plan was discovered, and the men were convicted.
- In 1995, a man entered Canada from Alaska on his way to North Carolina. Canadian custom officials stopped the man and found him in possession of several guns, $98,000, and a container of white powder, which was identified as ricin.
- In 1997, a man shot his stepson in the face. Investigators discovered a makeshift laboratory in his basement and found agents such as ricin and nicotine sulfate.
The use of this poison is not limited to the United States.
- In December 2002, six terrorist suspects were arrested in Manchester, England. Their apartment was serving as a "ricin laboratory." Among them was a 27-year-old chemist who was producing the toxin.
- On January 5, 2003, British police raided two residences around London and found traces of the poison, which led to an investigation of a possible Chechen separatist plan to attack the Russian embassy with the toxin. Several arrests were made.
Reviewed on 3/17/2020
United States Centers for Disease Control and Prevention. "Facts about Ricin." 2013.
WILX 10 News. "Ricin: What Makes It So Deadly?"