PRINCIPLES OF TOXICOLOGY

404 PROPERTIES AND EFFECTS OF ORGANIC SOLVENTS
Figure 16.32 Nitrobenzene.
Figure 16.33 Dinitrophenol.
confusion, vertigo, nausea, loss of cognition, hyperalgesia, paresthesia, and polyneuritis have been
reported as well as spleen and liver damage. Both the cyanogenic and anemiagenic potential of
nitrobenzene were listed as considerably greater than those of aniline, and the overall potential for
producing the blood effects was second only to that of dinitrobenzene. There is some risk of
reproductive toxicity shown by a decrease in rat fertility following exposure. No genetic toxicity has
been noted. Industrially important exposure to nitrobenzene may be evaluated by measurements of
p-nitrophenol, expressed in conjunction with urinary creatinine.
Among the six isomers of dinitrophenol (DNP) (see Figure 16.33), the one most commonly used
for industrial purposes is 2,4-dinitrophenol. The isomers often are kept as a mixture and are involved
in the synthesis of dyestuffs, picric acid, picramic acid, as herbicides, and in the manufacture of the
photographic developers.
Local application of DNP causes yellow staining of skin and may cause dermatitis due to either
primary irritation or to allergic sensitivity. In general, DNP disrupts oxidative phosphorylation,
resulting in increased metabolism, oxygen consumption, and heat production. Acute poisoning is
characterized by the onset of fatigue, sudden thirst, sweating, and oppression of the chest. There may
be rapid respiration, tachycardia, and a rise in body temperature. In cases of less severe poisoning, the
symptoms may include nausea, vomiting, anorexia, weakness, dizziness, vertigo, headache, and
sweating. The onset of effects is rapid, and death or recovery may occur within 1 or 2 days following
massive exposure. Chronic exposure may result in kidney and liver damage and in cataract formation.
While no federal standards have been set for dinitrophenol, an exposure limit of 0.2 mg/m 3 has been
suggested on the basis of data for dinitro cresol.
16.16 TOXIC PROPERTIES OF REPRESENTATIVE NITRILES (ALKYL CYANIDES)
The nitriles (e.g., acrylonitrile, acetonitrile) are organic cyanide compounds (see structures in Figure
16.34). They are nonpolar and are readily absorbed by all routes. Because some of these compounds
dissociate to produce free cyanide, the adverse effects they produce are comparable to those of cyanide