Document nVnXMvk6L57EaxxL641KdE48

38--Industrial Toxicology employees exposed to vanadium pentoxide over a period of nine years were observed About 20 of the exposed group were employed continuously for more than eight years One employee exposed to the dust showed convul sive cough with occasional spitting of blood, shortness of breath, palpitation on exertion, chest pains, bronchitis and bronchospasm, em physematous chest, elevated blood pressure, and a rebculated pattern on the chest X ray The pallor which commonly accompanies vanadium pentoxide exposure was attributed to its action in constricting the capillaries in the skin rather than to anemia Blood counts showed no anemia Vinyl acetate is considered a chemical of low toxicity, based not only on the findings in relatively limited animal experimentation, but also on years of use experience No systemic effects have been reported, and no chrome effects or sensitization have been noted As usually handled, no health hazard is present, either from inhalation of the vapor or con tact of liquid with the skin or eyes There are no indications for other than usual preemployment or periodic physical ex aminations for those who will handle vinyl acetate, nor would there seem to be any spe cial physical conditions making exposure a particular hazard The primary hazard m handling vinyl ace tate is due to its flammability rather than its effect on health Vinyl chloride (chloroethylene) is a gaseous chlonnated hydrocarbon used as a refrigerant but primarily as a raw material in the plastics industry It is an anesthetic in high concen trations. Vinyl propionate is an unsaturated ester which appears to have an astonishingly high toxicity for a class of compounds known for their low toxicity Rats exposed to 4 ppm showed stimulation and then depression of respiration, and died if not removed from the exposure Daily exposure did not seem to result in accumulation Vinylidene chloride (1,1-dichloroethylene) is a chlonnated hydrocarbon of about the same vapor toxicity as ethylene dichlonde 1176 The mam hazard of vinylidene chlonde is the ease with which it forms peroxides on ex posure to air or oxygen The peroxide is ab sorbed on the surface of the polymer which precipitates An attempt to filter off or to dry the polymer usually results m a violent ex plosion Usually, the whole mixture quickly becomes explosive if the polymer is left in the suspension This compound should be stored in a closed system with oxygen or air excluded, prefer ably, it should be kept under a positive pres sure of an inert gas. X Xylene is a solvent mixture of the ortho, meta, and para isomers It resembles benzene in many physical and chemical properties, but does not produce the chronic blood diseases characteristic of benzene absorption Xylene's severe narcotic action is usually noted when concentrations exceed 200 ppm Repeated skm contact may produce a derma titis Z Zinc and Zinc oxide. Inhalation of a con siderable quantity of freshly formed fume, usually from welding on zinc coated metal, will produce "metal fume fever," which is highly disabling but usually the individual re covers completely within 24 hr Zirconium is principally used in massive forms and as powder by the Atomic Energy Commission It is an extreme fire and ex plosion hazard in the dust or powdered form Its health hazard for both acute and chronic exposures is low Animal experiments on in halation and ingestion and evaluation of the skin effects of zirconium ointments all support the fact that no cases of industrial systemic poisonings have been reported. Sources of Help Many associations are concerned with indus trial toxicology problems Some are prepared to provide consultation service to nonmem bers, all have a wealth of available technical information Organizations having a high degree of in terest in industrial toxicology include the fol-