Potassium permanganate is a powerful oxidizing agent, and is largely used as a
disinfectant. In the solid form or in strong solution, potassium permanganate is a
powerful corrosive, and in dilute solution it acts as an irritant.
Manganese Dioxide, MnOi..—This is the common black ore of manganese, which is
called pyrolusite. It serves as the source of nearly all the manganese salts, and is largely
used for the manufacture of chlorine.
Acute Poisoning.—Acute poisoning occurs when a large quantity of a salt of manga-
nese, especially potassium permanganate, is taken internally.
Symptoms.—-These are burning pain in the mouth, throat and stomach, spreading
over the whole abdomen, intense thirst, difficulty in swallowing, almost continuous vomit-
ing and difficult breathing. The salt corrodes the tongue and pharynx, and stains the
parts black or dark-brown. Death occurs from paralysis of the heart.
Fatal Dose and Fatal Period.—One and two grains of potassium permanganate have
respectively caused alarming symptoms. Two hundred and twenty-five to three hundred
grains of the crystals of potassium permanganate have caused death. Death has occurred
in thirty-five minutes after a handful of the crystals had been swallowed in a tumbler
of beer. In Lucknow a female child, 2 years old, died from suffocation due to oadema
glottidis in twenty-seven hours after she had taken about half a teaspoonful of potassium
permanganate. A mechanic died four days after he had irrigated his urethra for two days
with 25 grammes of potassium permanganate dissolved in a tea-cupful of water.51
Treatment.—Lavage the stomach carefully with charcoal. Give white of egg and
milk. Administer intravenous injection of calcium bromide and intramuscular injection
of calcium gluconate. Treat the symptoms on general lines.
Post-mortem Appearances.—Signs of corrosion if a strongly concentrated solution
or the solid form of potassium permanganate is taken. The mouth, pharynx and
oesophagus are often corroded and blackened. The mucous membrane of the stomach
is intensely hypersemic and inflamed, and may be corroded at places. The duodenum
shows similar appearances. The parts that escape corrosion are usually congested and
inflamed. (Edema of the glottis and inflammation of the larynx and trachea have been
Chronic Poisoning.—This occurs in workers who constantly inhale the fine dust of
manganese dioxide in. manganese mines or in factories where manganese salts and manga-
nese steel are manufactured.
Symptoms.—These usually appear in workers after they have inhaled manganese
dust for at least three months, and resemble very much the symptoms of Parkinson's
disease. They are muscular weakness with marked tonicity and rigidity, difficulty in
walking with a spastic gait intentional tremors, cramps in the legs with muscular twitch-
ings, increased tendon reflexes, langour, sleepiness, monotonous scanning speech, stolid
mask-like face and emotional disturbances, such as purposeless crying and laughing.
Memory and sexual power are diminished. Progressive bulbar paralysis and amyotrophic
lateral sclerosis are also observed in chronic poisoning.
Treatment—The patient should be removed from the source of danger. Intravenous
injection of 15 grains of sodium thiosulphate in 10 cc. of water should be administered
every alternate day. Milk with calcium lactate or gluconate should be given. Copious
quantities of water and cathartics should be given to aid the elimination of manganese.
Prophylactic measures should be adopted to protect the workers by using exhaust fans
and controlling the dust by wet processes.
Post-mortem Appearances.—Cirrhosis of the liver is often found.52 The lungs are
frequently cedematous or pneumonic. Grave degenerative changes are present in the
brain with atrophy of ganglion cells, especially in the globus pallidus, putamen, and
nucleus claudatus and with degeneration of Forel's bundle.5* The findings are similar
to hepato-lenticular degeneration.
Chemical Tests.—1. A solution, of ammonium chloride, ammonia and ammonium
sulphide gives a salmon-coloured precipitate with a solution of a manganese salt. Caustic
soda or potash, when added to a solution of a salt of manganese, yields a white precipitate,
which becomes brown when shaken. A solution of bleaching powder produces a black
precipitate with a solution of a salt of manganese.
2. When fused with sodium carbonate and potassium nitrate, manganese compounds
yield a green mass of manganese. The green mass dissolves in a small quantity of cold
water, forming a dark green solution. If this solution is poured into a large volume of
water, a purple solution of permanganate and a brown precipitate of hydrated manganese
dioxide are formed.
51. Willimott and Freiman, Brit. Meet. J., Jan. 11, 1936, p. 58.
52. Handovsky, Arch. Exp. Path. Phar., 1926, 110, p. 265; Analyst, 1926, 51, p. 362.
53. Leschke, Clinic. Toxicology, Eng. Transl. by Stewart and Dorrer, 1934, p. 81.