Document 44jeZaYmmpq1XY6eXgaMa3oNx

ELEMENTS OF INDUSTRIAL TOXICOLOGY changes m the cornea to develop There is in excessive amounts, can produce a fibrobc no evidence of systemic injury associated change in die lungs or silicosis. with these eye injuries Sion untabon and staining may be the result of skm contact. See Hygienic Guide Silica is found m industry in the forms of quartz or sand, quartzite, sandstone, flint, tnpoli, diatomaceous earth, and as an im Radioactive elements and compounds that are tone are discussed m Chapter 42, "Ion izing Radiation " portant constituent in chert, granite, and other kinds of minerals. Whatever the form and maimer of use, exposure to free silica should be kept as low as possible by dust Rotenone is the active constituent of the dems and cube plants, as well as of many other leguminous plants It is highly tone to insects but of relatively small hazard to mammals, and is therefore widely used as an insecticide The powdered plant material is irritating to die skm and causes a derma titis in a large proportion of die workmen handling it, and inhalation of large amounts suppression methods There is no method known for removing fibrobc tissue hum the lungs, consequently, silicosis is incurable For a discussion of the mechanism and symptoms of silicosis, see Chapter 39, "In dustrial Hygiene " Also note the method of calculating threshold limit values for min eral dusts given m Table 40-B in this chapter of rotenone dust will produce a severe pul Also see Industrial Data Sheet 531 and monary irritation Hygienic Guide. These hazards can be readily controlled by enclosure and exhausting of the equip ment in which the material is handled and by careful peisonal hygiene. Sodium chlorate is a solid oxidizing agent which, with reducing agents such as sugar, coal dust, shellac, sawdust, or other organic materials, can form explosive mixtures that Selenium compounds are uniformly highly tone, although toxicity vanes somewhat ac cording to die solubility of the specific com pound The chronic effects of selenium were first noticed m "alkali disease" of cattle feeding on selenium-bearing forage It is may be detonated by friction or shock. Sodium chlorate is generally shipped in boxes or kegs lined with heavy brown pa per. After die materia] is removed from the container, both the lining and the box or keg should be bunted immediately. known that rats on a diet containing 350 |i Chlorate solutions are widely used for the of selenium per kg of body weight show destruction of weeds and other noxious definite symptoms of toxicity after a few plants The clothing of workmen on these weeks. Symptoms are a garlicky odor of die breath, which may persist for a long time after the exposure is terminated, nervous ness, gastrointestinal disturbances, loss of jobs, if saturated with the solution, can be ignited either through friction or through smoking Combustion in such cases is prac tically explosive, and the mjunes are likely to be fatal. weight, and great pallor Walking on chlorate spilled on the floor Although all the selenium compounds are toxic, exposures to hydrogen selemde and to selenium oxychloride are likely to be the most severe Selenium oxychloride produces extremely severe blisters and bums A mmiitw drop off the liquid on the don will produce a thirddegree burn Immediate washing with plen ty of water will reduce die seventy and extent of the bum but will generally not prevent it can also cause serious bums The matenal should be handled over smooth, impervious floors, and spillage should be cleaned up im mediately Impervious clothing should be worn while chlorate solutions are being handled. Clothing should be thoroughly washed at the end of the shift to remove spilled material, and should be nnsed dur ing the shift whenever matenal is spilled onrt. Large quantities of chlorates should be See also Hydrogen selenide and Hygienic Guide SOica is generally recognized as the most hazardous of the dusts which, when inhaled stored in an isolated fire-resistant building, conspicuously marked with the nature and hazards of the contents Such buildings should not be used for any other purpose, no other chemicals should be stored there. 40-51