By Mayo Clinic Staff

If you think you've been exposed to ricin, get into fresh air and call 911 or your local emergency number right away.

Ricin is a poison that can be made from the waste left when castor beans are made into castor oil. The poison can get into cells in the body. It can kill the cells by keeping them from making the proteins they need.

Ricin can be used as a weapon. It can be turned into a mist and inhaled. It also can be consumed in poisoned food or from a water supply that has it. Or it can be given in a shot.

Symptoms of ricin poisoning depend on whether a person breathes in the ricin, eats it or gets it in a shot. When breathed in, ricin causes fever, chest tightness, cough and breathing problems. Ricin can cause a fluid buildup in the lungs, known as pulmonary edema.

If ricin is eaten, it can cause vomiting and diarrhea. It can cause bleeding in the gut and organ damage. The poison can kill a person within three days. Even a small amount of ricin can kill.

There's no good test to confirm exposure to ricin. There's no vaccine for or way to counter ricin poisoning. Treatment might lessen the effects of the poison.

While waiting for emergency medical help, follow these steps from the Centers for Disease Control and Prevention:

• Get away from the area where the ricin is as fast as possible. Get into fresh air.
• Take off clothes that might have ricin on them. Don't pull clothes over the head. Cut them off if needed.
• Use a lot of soap and water to rinse skin exposed to ricin. For burning eyes or blurry vision, rinse the eyes with water for 10 to 15 minutes. Remove contact lenses and put them with any exposed clothing that will be discarded. Wash eyeglasses with soap and water.
• Get rid of exposed clothing by sealing it in a plastic bag. Enclose that bag in another plastic bag and seal it too.

Don't touch the clothes. Use rubber gloves, tongs or other such objects. Tell emergency workers where the bag of clothes is. Don't handle the bag.