Document 6621VxOma7e2X5eBDEjnLveg

I and eliminate small amounts without harm. When intake rales exceed the normal excretion level, build-up oc curs in the body. There is a safe level of absorption, and if the con centration* of load dust in the air of work areas is kept below the threshold limit, there should be no ' difficulty. 89. The importance of maintain ing the concentration of air-borne lead at a very low value stems from lead's high toxicity and its tendency, in small amounts, to accumulate in tlie human system. When lead ab sorption in the body reaches a suf ficient degree, symptoms of poison ing or intoxication appear. Beryllium intoxication .90. Beryllium intoxication is a severe systemic disease that can re sult from the inhalation of massive doses of dust of metallic beryllium, beryllium oxide, and some soluble beryllium compounds. There are two forms of the disease'. One is an acute form of chemical pneumonitis with cough, pain, difficulty in breathing, cyanosis, and loss of weight. In the chronic type, known as berylliosis. there may be loss of appetite and weight, weakness, cough, extreme difficulty in breathing, cyanosis, and cardiac failure. Mortality is high in chronic beryllium intoxication, and many who survive suffer from pul monary distress. --* 91. Individual susceptibility ap parently is an important factor in the development of the disease.' In many instances, one employee has devel oped the severe symptoms while oth er employees doing the same work have show n no signs of disability. 92; Beryllium intoxication' has never been demonstrated in individ uals mining or handling ore only. There is no evidence of intoxication from the ingestion of bcrylliurii oxide, beryllium metal. or any of the beryl lium alloys. Only the inhalation of beryllium dust produces systemic, di-ease. j '93. Because of the severe nature of the disease and because there is no way of predicting who will de velop it. extreme care must be taken to control the dust and fume that arise in the handling of beryllium, itvdloys. and its compounds. Beryl lium is toxic in such small quantity as to be considered tlie most toxic of all elements yet investigated. Substance TABLE III. SELECTED TOXIC DUSTS AND FUMES Description ond Effect* Threshold Limit In MHUgroms per Cubic Meter of Air' Antimony Arsenic Borium (soluble compound*) Beryllium Chromic odd . ond Chromates Cyanide (01 CN) Oinitrobenzeno ( Fluoride* Hydroquinone Iron oxide fum* t,od leod arsenate Mogneslum oxide fume Gray metal often ouocloted with lead and arsenic. Ha-ordout from inhala tion ond ingestion. Soluble tolls may cause dermatitis. ..0.5 Silvery brittle crytlolline metal. Haz ardous from inhotalron ond Ingestion. t/*watly encountered . et aaenfc ,frf> oxide. J1 0.5 Soluble barium chloride and tulfide ere toxic when token by mouth. 0J Light weight, gray metal. The metal, low-fired oxides, soluble softs, ond some alloys era toxic by inhalation. 0.003 Red, brown, or block crystals. Caustic oction en mucous membranes or skin. Nonvolatile cyanides ere ingestion ho ards- Cyanides inhibit tissue' oxidetion upon inhalation and cause death. 0.1 5.0 (skin**) Yellowish crystal. Hazardous from skin absorption, inholotion, and Ingestion. 1.0 (skin**) Inorganic fluorides are highly Irritant ond toxle. 24 - Colorless heiogonol crystals. Contact with the skin may cause sensitization and Irrllollon. Excessive exposure to dutl may cause corneal Injury. 3.0 Major sources are cutting ond welding. 15.0 leod fumes ond lead compounds cauto poisoning after prolonged exposure. Most important meant of entry into body h Inhalation. Skin absorption is of significance only from such organic compounds os lead tetraethyl. 0.2 White crystals--highly toxic. White powder. Inholotion of freshly generated fume may couse metol fume fever. 0.15 15.0 These threshold limit values were adopted by the American Conference of Govern mental Industrial Hygienists in 1962. 94. When the soluble salts of beryllium, especially beryllium fluo ride. come 19 contact with cbts or abrasions on the.skin, deep qlccrs ..may be formed that heal very slowly. Complete surgical excision of the ul cer is sometimes required in order to effect healing. Metal fume fever 95. Metal fume fever is an acute condition of short duration caused by a brief High exposure to, the freshly generated, fumes of mcfals such as zinfc or magnesium or their oxides. Symptoms appear from four to twelve hours after exposure and consist of fever and shakihg chills. There is complete, recovery usually within one day. and ordinarily the employee can return to the same job without recurrence. However, after a period in which there has been no contact with the fume, for example, 98 National Safety Newi, June 1963 TABLE III. SELECTED TOXIC DUSTS AND .FUMES (Ccninued) ribte individuals. Examples of such' Substance Manganese Description end Effects . Threshold limit In' Milligrams per Cubic Meter of Air*' Silvery gray metd. Hazardous from. 5JO inhalation of fumes or dust. agents are certain animal products. . foods, drugs, and chemicals. The bodily systems usually involved, in allergic reactions, which jnay be quite severe, are'the skin, respiratory sys tem. and gastrointestinal system. Oc casionally, two or more systems are * Pentochloraphenol Dork-colored flakes. Harmful dust. Emits toxic fumes when heated. 0J (skin**)'. A involved. Some of the. allergic reac tions are dermatitis, hay fever, asth Phosphorus (yellow) Picric acid __ Poisonous motrAf by iflhcfotJon. Sever* bum hazard from skin contact. Yellow crystals or liquid. Explosive-- particularly metallic solts. Emits toxic fumes-on decomposition. O.l' 0.1 (skin**) ma, and hives. 99. Usually, the victim ts'subject ed to a series of exposures without any reactions during which sensiti- zation is built up. These exposures may occur continuously for yean. Selenium compounds m Sodium hydroxide Tellurium Toxicity varies somewhat according to the solubility of ihe specific ` com pound, Often comes contact dermatitis. .White, deliquescent pieces or lumps. . .Has severe oction upon aB body thsue. 0.1 2.0 Similar to selenium chemlcolly and In physiologtcol effects. - 0.1 i Titanium dioxide Whire to black powder. Considered in 15.0 . the nuisance category. Trinitrotoluene Colorless to yellow monoclinic crystals. Emits toxic fumes of oxides of nitrogen when heated to decomposition. Highly Ulskin**) Then, at the end'of the "incubation . period" which varies according to the individual, a reaction is pro duced. 100. For a true allergic rcaction.two factors are.required: . a! A history of prior exposure toi the material involved (sometimes not known by affected employees), b. A "challenge dose" of the mate rial. which provokes the allergic te- ' action. 101. Continuous exposutes may act as "desensitizing doses." and poisonous explosive. under these conditions an! allergic Uranium Highly toxic and -0 'radiation hazard that requires special, consideration. 0.05 (soluble com pounds) 1 0.25 (insoluble eom pounds) individual may work without incident for long periods of time only to find that re-exposure after removal'from the sensitizing material (such as after a vacation) causes an .allergic re Vanadium pentoxide ' Yellow to red crystojs. Acts chiefly ai ' en irritant to the conjunctiva and re spiratory tract. 0-S (dust! 0.1 (fume) sponse to recur. 102. Medical and engineering rec ommendations to prevent allergic '. J. Zinc oxide fume ' Zirconium compounds Amorphous white or yellow powder. The powder is essentially nontoxic but freshly generated fume may cause metal fume fever. '5.0 Most `compounds era insoluble end have low toxicity. sV reactions are based on prevention of exposure by means of persona] pro tective equipment, ventilation meth ods, or removal of sensitized individ uals from the, exposure. Infections Infection ond pneumoconiosis * i; I These threshold limit values were adopted by the American Conference of Govern mental Industrial Hygienists In 1962. *?The word "skin'' in this table indicates that the substance can penetrate the slua to contribute to the exposure. after a layoff, resumption of exposure is jikety to bring on an attack. , 96. To cause, metaJ 'fume fever,-heavy concentrations of fumes an? required. Zioc oxide, fume is the most common ' source, but cases caused by the inhalation of fumes froiri.magnesium oxide, copper oxide, and other metallic oxides have also ibeen reported. The condition- does . not occur from the handling of these it results only from the inhalation of extremely fine particles freshly formed as fume (nascemfume). 97. Nickel, mercury^ and other metals may also produce a* fever fol lowed by the toxic effects of the element. Allergic Reactions 98. When in the form of dust, a large number of materials may cause 103. The presence of pulmonary disease. that significantly interferes with the natural defenses ' against . foreign panicles may increase sus ceptibility to pneumoconiosis. Con- . versely, a pneumoconiotic lung is rppre prone to infection. For exam ple,. tuberculosis occurs more fre quently among jilicotics than among normal persons. Severe disability or death of a silicotic, when caused by pulmonary conditions* usually results ' from complicating tuberculosis either alone or combined with other infec tions. Bacteria and fungi - J. oxides in powder form. Apparently, various allergic reactions in suscep- - 104. The possibility of lung in- National Safety Newt, June 1963 99 t f- :\ .i ' i :1