On February 2, 2004, a white powder
was found in the mail room area of the Dirksen building
where the Senate Majority Leader is located.Analyses of
the material identified it as ricin, a lethal plant
protein. No one became ill, but three Senate office
buildings were closed.
Let us take a look at this lethal
In the PEAC tool, Ricin falls under
the general heading of “Bio Toxins” using the menu
selection, “Lookup By:” The following information is
displayed under ricin:
Substances - Toxic and/or Corrosive (Combustible)
powder, a very toxic lectin and hemaglutinin isolated
from the castor bean. When weaponized, exposure likely
through inhalation of a toxin aerosol.
Ricin is a
cytotoxin (causes cellular destruction). LD(50) approx.
3 micrograms/kg. Routes are inhalation, ingestion, and
injection. Has been used as an assassination
refers to the 2000 Emergency Response Guidebook. The
PEAC user can pull up further instructions on health
hazards, public safety, protective clothing, evacuation,
first aid, and fires pertaining to this guide
approximately 3 micrograms/kg” means that the lethal
dose (50% chance of death) is approximately 3 micrograms
per kilogram of body weight. A 210 microgram dose can
kill a 70 kg (155 lb) man. A 210 microgram dose is very
small, a little smaller than the size of a pinhead. The
U.S. Center for Disease Control says 500 micrograms of
ricin can kill an adult, but the amount required to kill
depends upon whether ricin is injected, inhaled, or
TEEL2, and TEEL3” are acronyms for “Temporary Emergency
Exposure Limit”, levels 1, 2, and 3.
The units are
“milligrams per cubic meter” and represent
concentrations in the air. They were developed by the
U.S. Dept. of Energy to serve as temporary numbers until
the peer-reviewed Emergency Response Planning Guidelines
(ERPG) are published. Details on TEELs may be found at
The CAS NO
is a unique number assigned by the American Chemical
Society for ricin. CAS is an acronym for Chemical
Abstract Services; it is used as an index number to aid
researchers in locating information about specific
“has been used as an assassination weapon” refer to a
1978 incident. George Markov, a Bulgarian journalist
living in London, died after he was attacked by a man
with an umbrella which was rigged to inject a ricin
pellet under Markov’s skin.
Characteristics of Ricin
Ricin is a
poison made from castor beans. Castor beans are grown
worldwide and are readily available. Castor beans are
normally used to make castor oil. Ricin is part of the
waste mash produced after extraction of castor oil. If
purified and dried, ricin is an odorless, white powder.
Ricin can also be in the form of pellets or dissolved in
water or weak acids such as vinegar or dilute phosphoric
acid or dilute alcohol. Ricin can be stored for years
and is unaffected by very hot or cold temperatures.
Crude ricin may be buff or otherwise colored. It can be
weaponized and dispersed as a mist.
Can People Be Exposed to Ricin
It takes a deliberate act to make
ricin and use it to poison people. Accidental exposure
to ricin is unlikely. Ricin poisoning is not contagious;
it cannot be spread from person to person through casual
contact. Skin contact is harmless if there are no cuts
in the skin. Ricin may have some potential medical uses
such as in bone marrow transplants and treatment of
cancer, according to the Center for Disease Control
(under the U.S. Dept of Health and Human Services).
Exposure routes are inhalation,
injection, or ingestion. People can inhale ricin powder
or mist. Ricin can be put into the food or water supply.
An amount greater than 200 or 500 micrograms is required
to kill a person if swallowed compared with direct
injection or inhalation. Ricin is not very well absorbed
through the gastrointestinal tract. People have also
been poisoned from eating castor beans. Most of what we
know on inhalation is from animal studies.
There is no antidote for ricin
poisoning. The most important factor is to avoid
exposure in the first place.
Symptoms of Ricin
Ricin works by preventing the
person’s body cells from making protein. Symptoms depend
upon whether ricin is inhaled or ingested. A person
displaying these symptoms does not necessarily mean that
the person has been exposed to ricin.
Inhalation: Respiratory distress
(difficulty breathing) symptoms appear within about 12
hours (within a few hours after inhaling significant
amounts of ricin). Other symptoms are fever, cough,
nausea, fatigue, and tightness in the chest. Heavy
sweating may follow as well as pulmonary edema (fluid
buildup in the lungs). Fluid buildup in the lungs makes
breathing even more difficult, and the skin may turn
bluish. Finally, low blood pressure and respiratory
failure may occur.
If significant amount of ricin is ingested, symptoms are
vomiting and diarrhea (diarrhea may be bloody). Severe
dehydration may result followed by low blood pressure.
There may be hallucinations, seizures, muscle pain, and
blood in the urine. Within several days, the person’s
liver, kidneys, and other vital organs may stop working
and the person dies.
Eye Contact: Ricin in powder or mist form can cause
redness and pain especially to the eyes.
has not occurred within 5 days, the person usually
Exposure to certain other toxic
chemical or biological agents can produce similar
symptoms. These include but are not necessarily limited
enterotoxin B; exposure to pyrolysis byproducts of
organofluorines such as Teflon or Kevlar; oxides of
nitrogen, and phosgene.
Enteric pathogens, poisonous mushrooms, caustics, iron,
another very toxic bio toxin derived from seeds of a
different plant which produces similar symptoms.
Treatment for Ricin Poisoning
No antidote exists for ricin
poisoning. According to the Center for Disease Control,
there is no definitive test to determine whether a
person has been poisoned by ricin. Medical treatment is:
(1) supportive and (2) getting the ricin off or out of
the body as quickly as possible. Getting the ricin off
or out of the body means: (1) removing contaminated
clothing, washing the skin, and flushing the eyes with
water if contacted with dust or mist, or (2) flushing
the stomach with activated charcoal if ricin was very
recently ingested. Supportive treatment include measures
to help patients breath, giving intravenous fluids, and
giving medications to treat conditions such as seizures
or low blood pressure.
and First Aid
The U.S. Department of Health and
Human Services, Centers for Disease Control and
Prevention, recommends the following in a Feb. 5, 2004
First, get fresh air by leaving the area
where the ricin was released. Moving to an area with
fresh air is a good way to reduce the possibility of
death from exposure to ricin.
If the ricin release was outside, move
away from the area where the ricin was released.
If the ricin release was indoors, get out
of the building.
If you are near a release of ricin,
emergency coordinators may tell you to either evacuate
the area or to “shelter in place” inside a building to
avoid being exposed to the chemical. For more
information on evacuation during a chemical emergency,
About Evacuation. For more information on sheltering
in place during a chemical emergency, see Facts
About Sheltering in Place
think you may have been exposed to ricin, you should
remove your clothing, rapidly wash your entire body with
soap and water, and get medical care as quickly as
Removing your clothing:
Quickly take off clothing that may have
ricin on it. Any clothing that has to be pulled over the
head should be cut off the body instead of pulled over
If you are helping other people remove
their clothing, try to avoid touching any contaminated
areas, and remove the clothing as quickly as possible.
As quickly as possible, wash any ricin
from your skin with large amounts of soap and water.
Washing with soap and water will help protect people
from any chemicals on their bodies.
If your eyes are burning or your vision is
blurred, rinse your eyes with plain water for 10 to 15
minutes. If you wear contacts, remove them and put them
with the contaminated clothing. Do not put the contacts
back in your eyes (even if they are not disposable
contacts). If you wear eyeglasses, wash them with soap
and water. You can put your eyeglasses back on after you
Disposing of your clothes:
After you have washed yourself, place your
clothing inside a plastic bag. Avoid touching
contaminated areas of the clothing. If you can't avoid
touching contaminated areas, or you aren't sure where
the contaminated areas are, wear rubber gloves, turn the
bag inside out and use it to pick up the clothing, or
put the clothing in the bag using tongs, tool handles,
sticks, or similar objects. Anything that touches the
contaminated clothing should also be placed in the bag.
If you wear contacts, put them in the plastic bag, too.
Seal the bag, and then seal that bag
inside another plastic bag. Disposing of your clothing
in this way will help protect you and other people from
any chemicals that might be on your clothes.
When the local or state health department
or emergency personnel arrive, tell them what you did
with your clothes. The health department or emergency
personnel will arrange for further disposal. Do not
handle the plastic bags yourself.
For more information about cleaning your
body and disposing of your clothes after a chemical
release, see Chemical
Agents: Facts About Personal Cleaning and Disposal of
Contaminated Clothing, .
If someone has ingested ricin, do not
induce vomiting or give fluids to drink.
Seek medical attention right away.
Identification of Ricin
identification of ricin is possible if specialized tools
are available and people are trained to use them. These
include a handheld chromatographic antibody-based assay
plates (an enzyme-linked immunosorbent assay, or ELISA) to get
preliminary readings. The plates are sensitive and
generally do not produce false readings. Laboratories
generally use a more exacting ELISA procedure. The
Maryland Public Health Laboratory used an ELISA
procedure using time-resolved fluorescence immunoassay
to test 65 samples taken from the postal facility
serving Capitol Hill for ricin [from Chemical and
Engineering News, Feb 9, 2004, page 11].
information on laboratory testing can be found at the