Chemical reference numbers (CAS) of common forms: Cyanide
57-12-5, Zinc Cyanide 557-21-1,
Sodium Cyanide 143-33-9, Potassium Cyanide 151-50-8,
Hydrogen Cyanide 74-90-8
What is cyanide?
Cyanide is very poisonous. Cyanide can exist as a gas, liquid or white crystal powder.
Cyanide is used in the electroplating industry, in metal cleaning operations, and as an
industrial bug killer. Breathing the gas, eating the liquid or solid forms can make people
suddenly lose consciousness or cause death.
There are no common uses of cyanide in the home. Most cyanide in the environment
results from industrial processes and from improper waste disposal.
How are people exposed to cyanide?
Breathing: Cyanide gas can be found in industrial emissions and car
exhaust, cigarette smoke and certain papers and plastics as they burn. It is also possible
to breathe or eat cyanide dust when working with cyanide powder. If people use a
contaminated water supply, they can breathe cyanide when they cook or shower with the
Drinking/Eating: Cyanide is sometimes found in contaminated drinking
water. People can be exposed when they drink contaminated water. People who handle
contaminated soil may be exposed when they eat or touch their mouths with dirty hands.
Touching: Cyanide can enter the body through skin when people handle
the chemical, contaminated soil or contaminated water. People can be exposed to cyanide if
they wash or bathe with contaminated water.
Do standards exist for regulating cyanide?
Water: The federal drinking water standard for cyanide is set at 200
parts per billion (ppb). We suggest you stop drinking water containing more than 200 ppb
Air: No standards exist for the amount of cyanide allowed in the air
of homes. We use a formula to convert workplace limits to suggested home limits. Based on
the formula, we recommend cyanide levels be no higher than 90 ppb. Most people cant
smell cyanide until levels reach 600 ppb. Cyanide compounds smell like bitter almonds to
some people, while others cannot smell them at all. If you can smell the chemical, the
level is too high to be safe.
The Wisconsin Department of Natural Resources regulates the amount of cyanide that can
be released by industries.
Will exposure to cyanide result in harmful health effects?
The following health effects are described in cases of suicide or accidental exposure
to high levels of cyanide compounds. These effects are not expected following low-dose
- Irritation of skin and mucous membranes (causing redness or flushing of skin)
- Headaches, dizziness and loss of coordination
- Nausea and vomiting
- Rapid, deep breathing or gasping
- Rapid pulse rate and increased blood pressure
- Muscle spasms and convulsions
- Loss of consciousness and death.
The following health effects can occur after several years of exposure to low levels of
No studies show a relationship
between exposure to cyanide and the development of cancer.
Reproductive Effects: Studies of laboratory animals show exposure to
cyanide resulted in birth defects.
Organ Systems: Cyanide can cause nerve damage affecting hearing,
vision, and muscle coordination. Damage to the thyroid gland is also possible, resulting
in changes of metabolism in adults and slowing growth or development in children.
In general, chemicals affect the same organ systems in all people who are exposed. A
person's reaction depends on several things, including individual health, heredity,
previous exposure to chemicals including medicines, and personal habits such as smoking or
Its also important to consider the length of exposure to the chemical; the amount
of chemical exposure; and whether the chemical was inhaled, touched, or eaten.
Can a medical test determine exposure to cyanide?
Doctors can test urine for "thiocyanate" shortly after exposure to cyanide.
Blood levels of cyanide can indicate recent exposure. Cigarette smokers generally have
higher levels of cyanide-related compounds in their bodies than non-smokers.
Seek medical advice if you have any symptoms that you think may be related to chemical
(P-44594 Revised 12/2010)
This fact sheet summarizes information about this chemical and is not a complete
listing of all possible effects. It does not refer to work exposure or emergency
Back to Toxic Chemical Fact Sheet