This document summarizes the properties and effects of cyanide poisoning. It discusses that cyanide is a rapidly acting, highly toxic salt that inhibits cellular respiration. The three main types are potassium cyanide, sodium cyanide, and hydrogen cyanide. Cyanide binds to metal complexes in mitochondria, blocking the electron transport chain and preventing ATP production. This deprives cells, especially in the brain and heart, of oxygen. Symptoms of cyanide poisoning include headache, nausea, confusion and respiratory failure. Cyanide is used in mining for gold and silver, electroplating, and has some medical applications in lowering blood pressure.

1. Cyanide &
Happiness:
The mystery of
its lethal
poisoning …

2. Introduction
• What is Cyanide?
• A salt or ester of hydrocyanic acid, containing the anion
CN− or the group −CN. The salts are generally extremely
toxic.
• It’s most notable characteristic is its rapid effect.
Cyanide’s drastic effects can be prominent only a few
seconds after its inhalation.
• Cyanide is most dangerous when it is present in high
concentrations in closed areas, unventilated
areas, because it has a high diffusion rate, so it won’t
have much effect if it were released in the open.

3. Structure & Types of
Cyanide
1. KCN – Potassium Cyanide
A colourless crystalline compound ,
similar in appearance to sugar ,
highly soluble in water.
Most of KCN is used in gold mining,
organic synthesis, and electroplating.
The toxicity of potassium cyanide when ingested depends on the
acidity of the stomach, because it must react with an acid to
become hydrogen cyanide, the deadly form of cyanide.

4. • NaCN= Sodium Cyanide.
It is a white, water-solube solid
and has a high affinity for metals,
which means it reacts vigorously
with them.
• When it reacts with gas, it forms Hydrogen Cyanide.
• Sodium cyanide is produced by treating hydrogen
cyanide with sodium hydroxide.

5. • HCN = Hydrogen Cyanide or Hydrocyanic acid.
• It is a colorless gaseous inorganic compound, which may
or may not have an odor. Its odor is usually “bitter
almond”. Some people have the inability to taste it. (
Genetic trait ;) )
• It is sometimes called prussic acid.
• It is a linear, weakly acidic, and has a triple bond
between Hydrogen and Nitrogen.
• Its is the most toxic type of all three types of Cyanides.

6. Mechanism of Action
• Cyanide is a lethal compound mainly because it inhibits
cellular respiration through hampering mitochondrial
cytochrome oxidase. It, also, blocks the transport
electron chain, preventing the movement of electrons.
• Cyanide blocks the action of Cytochrome a3 at complex 4
in the mitochondria, and thus preventing the reduction of
water as well as production of ATP.
• This blockage produces many problems, some of which
are:
• 1- High Oxygen concentration in the blood without
consumption.
• 2- No production of ATP, energy, which affects mainly the
brain and heart.
• 3- Lactic Acidosis as a result of using anaerobic metabolism.

10. Effect of Cyanide on
cells/muscles
• As mentioned before, Cyanide promotes metabolic
acidosis and anaerobic respiration, especially in cells that
require oxygen the most. As a result, heart muscles and
brain cells are the first to be affected by Cyanide
intoxication.
• The CNS which is very sensitive to the levels of
Oxygen, is going to malfunction very early in the
intoxication and cause respiratory dysfunction.
• Heart muscles are going to be oxygen-starved for a few
moments and will use anaerobic metabolism, which
cannot last for long before serious harm to the cells
occur.

12. Effect on Complex IV
• Cytochrome c Oxidase is a membrane protein
complex, complex IV, in the mitochondria, which
consists of Cytochrome a and a3 as well as two
copper centres.
• It is the last enzyme in the electron transport chain
of mitochondria. It receives electrons from each four
cytochrome c molecules and transfers them to a
single molecule of Oxygen.
• Cyanide has high affinity for certain sulfur
compounds as well as metallic complexes. The
cyanide ion may very rapidly bind to the (Fe3+)iron
ion in cytochrome a3, which inhibits its effect and
renders the Electron Transport Chain futile.

13. Dose of Death
• A dose of around 250 to 325 mg of potassium or
sodium cyanide is lethal in humans, and a lethal
case would have a blood level of around 1 mg mL1.
A blood level of greater than 0.2 mg mL is toxic.
• Toxicity by cyanide is nominated – Histotoxic
hypoxia-

14. Signs & Symptoms
• The symptoms of poisoning include
headache, salivation
nausea, anxiety, confusion, vertigo, convulsions, par
alysis, unconsciousness coma, cardiac
arrhythmias, hypotension, and respiratory failure.
• Both venous blood and arterial blood remain
oxygenated, and hence the victim may appear pink.

15. Usage and
Processing
• Cyanide is mainly produced during
the mining of gold and silver. It helps dissolve these
metals and their ores.
• Cyanide is also used in electroplating, where it
stabilizes metal ions in the electrolyte solution prior
to their deposition.
• Cyanide has also some medical uses, such as:
• 1- Emergency situations ; to rapidly decrease blood
pressure.
• 2- The cyanide compound sodium nitroprusside is
used mainly to measure urine ketone bodies as a
follow-up to both diabetic & renal failure patients.

16. • Cyanide can be found in many substances, natural and
synthesized:
•
•
•
•
•
1- Cigarettes.
2- Synthesis & combustion of plastic.
3- Flora such as bitter almond, apricot, stone of peach.
4-Cassava tuber
5-Combustion polyurethane foam.

18. Thank You
Prepared by Amjad
Shamsi Basha,
Edited by
Mohammed Khalifa