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<br /> A dangerous fire ha.. d when exposed to heat "er flame. Explodes on
<br /> contact with diborane, bromine pentafluoride, permanganic acid,
<br /> - peroxomonosulfuric acid, and peroxodisulfuric acid. Forms sensitive,
<br /> explosive mixtures with iodine pentafluoride, silver perchlorate, nitryl
<br /> Perchlorate, nitric acid, liquid oxygen, ozone, arsenic pentafluoride +
<br /> potassium methoxide (explodes above 30°C) . Ignites on contact with
<br /> sodium peroxide + water, dioxygenyl tetrafluoroborate, iodine
<br /> heptafluoride, and dioxygen difluoride. Vigorous or incandescent
<br /> reaction with hydrogen + Raney nickel (above 2100C) , uranium
<br /> hexafluoride, and bromine trifluoride. Can react vigorously with
<br /> oxidizing materials, such as C12, Cr03, 02, NC104, 03, perchlorates,
<br /> (A1C13 + FC104) , (H2SO4 + permanganates) , K202,. (AgC104 + acetic acid) ,
<br /> Na202. Moderate explosion hazard when exposed to heat or flame. Use with
<br /> adequate ventilation. To fight fire, use foam, CO2, dry chemical.
<br /> Poisoning occurs most commonly via inhalation of the vapor, although
<br /> benzene can penetrate the skin and cause poisoning. Locally, benzene has
<br /> a comparatively strong irritating effect, producing erythema and
<br /> burning, and, in more severe cases, edema and even blistering. Exposure
<br /> to high concentrations of the vapor (3000 ppm or higher) may result from
<br /> failure of equipment or spillage. Such exposure, while rare in industry,
<br /> may cause acute poisoning, characterized by the narcotic action of
<br /> benzene on the central nervous system. The anesthetic action of benzene
<br /> is similar to that of other anesthetic gases, consisting of a
<br /> preliminary stage of excitation followed by depression and, if exposure
<br /> is continued, death through respiratory failure. The chronic, rather
<br /> than the acute form, of benzene poisoning is important in industry. It
<br /> is a recognized leukemogen. There is no specific blood picture occurring
<br /> in cases of chronic benzol poisoning. The bone marrow may be
<br /> hypoplastic, normal, or hyperplastic, the changes reflected in the
<br /> peripheral blood. Anemia, leucopenia, macrocytosis, reticulocytosis,
<br /> thrombocytopenia, high color index, and prolonged bleeding time may be
<br /> present. Cases of myeloid leukemia have been reported. For the worker,
<br /> repeated blood examinations are necessary, including hemoglobin
<br /> determinations, white and red cell counts, and differential smears.
<br /> Where a worker shows a progressive drop in either red or white cells, or
<br /> where the white count remains below < 5, 000/mm3 or the red count remains
<br /> below 4 .0 million/mm3, on two successive monthly examinations, the
<br /> worker should be immediately removed from benzene exposure. Elimination
<br /> is chiefly through the lungs, when fresh air is breathed. The portion
<br /> that is absorbed is oxidized, and the oxidation products are combined
<br /> with sulfuric and glycuronic acids and eliminated in the urine. This may
<br /> be used as a diagnostic sign. Benzene has a definite cumulative action,
<br /> and exposure to a relatively high concentration is not serious from the
<br /> point of view of causing damage to the blood-forming system, provided
<br /> the exposure is not repeated. In acute poisoning, the worker becomes
<br /> confused and dizzy, complains of tightening of the leg muscles and of
<br /> pressure over the forehead, then passes into a stage of excitement. If
<br /> allowed to remain exposed, he quickly becomes stupefied and lapses into
<br /> coma. In nonfatal cases, recovery is usually complete with no permanent
<br /> disability. In chronic poisoning the onset is slow, with the symptoms
<br /> vague; fatigue, headache, dizziness, nausea and loss of appetite, loss
<br /> of weight, and weakness are common complaints in early cases. Later,
<br /> pallor, nosebleeds, bleeding gums, menorrhagia, petechiae, and purpura
<br /> may develop. There is great individual variation in the signs and
<br /> symptoms of chronic benzene poisoning.
<br /> 10
<br /> site safety i Health Plan Rev./1.0
<br /> October 20, 1997
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