Document edVM3OaKXr44D7qY1jmXn1DE

G Gasoline vanes in composition, but is com monly a petroleum fraction containing hex anes, heptanes, and octanes with varying amounts of unsaturated, cyclic, and aromatic compounds A cracked gasoline may contain 50 percent or more compounds other than the saturated aliphatic hydrocarbons If the gasoline consists of saturated and un saturated aliphatic compounds and cyclic com pounds, it will be a narcotic and an irritant to the mucous membranes The mam toxic action will be depression of the central nerv ous system with symptoms of giddiness, dizzi ness, hilarity, and headache not unlike an alco holic intoxication Mild symptoms of this sort are apt to be produced by relabvely short ex posures to concentrations of 500 to 750 ppm of this land of gasoline In addition, mild blood changes, neuritis, and neurasthenias have been reported If the gasoline is made from a crude oil containing 40 percent or more of aromatics or is ennched in aromatics by the refining proc ess, the toxicity may be substantially higher The tetraethyl lead content of gasoline is low enough to make any lead exposures from ordinary handling and dispensing of gasoline m garages and filling stations negligible Tetraethyl lead can, however, present a toxic hazard by inhalation and absorption through the skm when entry is made mto tanks and other confined spaces that have contained leaded gasoline See Lead. Germanium, one of the less common metals which have some industrial uses, is employed particularly in the electronics industry for diodes and transistors It appears to be a rela bvely inert metal and has not been reported as the cause of any occupabonal diseases in man In animal experiments, the LDU for rats by mtrapentoneal injection was about 750 mg/kg of body weight when germanium oxide was buffered to near the neutral point Food con taining 1000 ppm or water containing 100 ppm was fatal to half of the young rats Re peated sublethal doses produced some tol erance to a subsequent lethal dose, but the tolerance dechned substanbally m six weeks Graphite has been repeatedly reported to produce a pneumoconiosis in workers in mines, mills, and electrode plants Several mvesbgators have done autopsies on men who died from graphite pneumoconiosis and found their lungs to contain fibrous masses with central necrosis, m addition to emphysema and gen eral fibrosis around the blood vessels and lymph channels The typical X-ray patterns start with a miliary "snow-storm" effect and progress to a pattern of sharply defined masses of various sizes in each lobe. H Halogenated hydrocarbons--see also the in dividual compounds--as used in industry are potent anesthebcs and more or less toxic On exposure to high concentrations the most com mon symptoms are nausea, vomiting, diarrhea, headache, and unconsciousness If unconsciousness occurs, it may be fol lowed by sudden death due to fibrillahon of the heart or respiratory failure, as has fre quently been observed in the medical use of these compounds After exposure to amounts which are large but not sufficient to produce sudden death, there may be severe kidney and liver damage eventually leading to death The most common halogenated hydrocar bons, arranged in the order of increasingly acute toxicity, are vinyl chloride, methyl chloride, ethyl chloride, ethylene dichlonde, ethyl bromide, carbon tetrachloride, dichloromethane, methyl chloroform, trichloroethylene, methyl bromide, tetrachloroethylene, pentachloroethane, and tetrachloroethane Tetrachloroethane is about 40 bmes as strong a nar cotic as vinvl chloride It should be noted that this is the increasing order of their ability to produce narcosis, which is not the same as the order of their chronic toxicity, the more common problem in industry An acute exposure to the more narcotic of these compounds may result m unconsciousness for surprisingly long penods, with eventual recovery Unconsciousness for eight weeks has been reported in a case of methyl bromide poisoning. Tetrachloroethane, the most toxic of the common chlonnated hydrocarbons, has no par ticular warning signs or symptoms and can produce extremely severe poisonings from continuous exposure to fairly low concentra tions Carbon tetrachloride, methyl chloride. 1147