240 CHEMISTRY AND TECHNOLOGY OF EXPLOSIVESm- Dinitrobenzene also forms an addition product with nitrobenzene which,
according to Lehmstedt [21], contains 1 mol. m- dinitrobenzene and 2 mol. of
nitrobenzene. Its melting point is 25°C.TOXICITY OF DINITROBENZENEDinitrobenzene-the commercial product consists mainly of m- dinitroben-
zene-is one of the most toxic industrial poisons and has been the cause of
a great number of fatal cases. Poisoning may be caused by inhaling the vapours
or by absorption through the skin. Although dinitrobenzene has relatively little
volatility, a concentration as low as 1 mg/m^3 may be sufficient to cause acute
poisoning, so great care should be taken to avoid toxic concentrations.
Dinitrobenzene is a strong poison, affecting the blood and the liver. It causes
the formation of methaemoglobin, which can be seen in the intense blue discol-
ouration-cyanosis-of the lips, mucous membranes and the face of the victim.
Kiese and his colleagues [22] working with dogs, found that subcutaneous
injections of m- dinitrobenzene given in quantities of 0.2-6 mg/kg over a long period
caused anaemia, cramps, paralysis and liver damage. When experimenting on
rats they were able to establish that animals suffering from chronic alcoholic poison-
ing, were more sensitive to m- dinitrobenzene than normal rats. The reverse was
also true-the narcotic action of alcohol was stronger when the rats were victims
of chronic m- dinitrobenzene poisoning.
According to Koelsch [23], chronic industrial poisoning by dinitrobenzene
may appear in two forms. One of them causes degeneration of haemoglobin and
in most cases recovery follows within 1-2 weeks. In exceptionally acute cases the
symptoms appear rapidly and are often followed by death within a few hours.
Another form of dinitrobenzene poisoning is characterized by delayed symptoms
which may appear from 1 to 3 months after exposure. Within 1-3 weeks after thefirst symptoms are manifested, degeneration of the liver takes place. Women are
particularly liable to this form of poisoning. The illness may last for about 2 weeks
in mild cases, while severe but not-fatal ones may last for 2 months. Some of the
dinitrobenzene is excreted unchanged with the urine, while some of it undergoes
a partial reduction in the body to a still more poisonous hydroxylamine deriv-
ative :(5)The medical literature (Staub [24]), dealing with industrial aspects of hygiene,
reports that in the one year 1900 in a German explosives factory, 41% of the work-
ers were poisoned by dinitrobenzene.
During World War I when dinitrobenzene was manufactured and widely