Document XO77XqLgzNEzqny4zQLE5261d

ELEMENTS OP INDUSTRIAL TOXICOLOGY Mercury and its compounds are not near ly so widely used as are lead compounds and consequently mercury poisoning is not so well known nor so often seen as is lead poi soning. Mercury metal is a liquid at room tem perature with a vapor pressure high enough to produce poisoning if a considerable area of the metal surface is exposed to air If mercury gets into the cracks of a wood or tile floor or into the pores of a concrete floor, the contamination may become so great as to necessitate replacement or seal ing of the floor before the plant or labora tory can be safely used again Although it cannot be removed, mercury can be sealed into such floors by covering them complete ly with an asphalt mashc, preferably after die vapor pressure of the mercury has been reduced by flooding the whole area with a lime sulfur spray To prevent such inconvenience, metallic mercury should be handled over impervious tables or containers with the surfaces de pressed and arranged to dram to a central point. Spilled mercury can then be collect ed and returned to stock A number of volatile mercury compounds are used m seed disinfection Examples arc ethyl mercury chloride and phosphate and the corresponding phenyl mercury com pounds. These materials are highly toxic When used without adequate enclosure and dust control, they can rapidly produce se vere mercurial intoxication These seedtreating compounds are also strong primary skm irritants and will cause itching, burn ing, and blistering on direct contact Such irritations heal slowly. The type of mercury intoxication com mon to industry is characterized by a tremor of die hands, irritation of the mucous mem branes of the mouth, excessive flow of sa liva, and changes m the personality. Poi soning by one of the volatile compounds may be more rapid so that personality changes are not so likely to be seen Inhalation of mercury vapor, usually in very high concentrations, may produce metal fume fever, which may disappear with no other apparent symptoms, or may be fol lowed by a pneumonitis or other symptoms of mercunalism. The ordinary toxic dust respirator does not protect against intoxication by metallic mercury or by the volatile seed-treating compounds, since they are in the form of vapor rather than dust A gas mask offers some protection, but if enclosure and local exhaust are not possible, the only effective protection is a supplied air respirator. See Industrial Data Sheet 203 and Hy gienic Guide. Mesityl oxide is a high-boiling, unsatu rated ketone which is thought to be some what more toxic than the ketones of lower molecular weights Metal hydrides (primary types) are com pounds of hydrogen and the alkali metals sodium, potassium, lithium, magnesium, cal cium, and strontium Information an the health hazards of metal hydrides is limited Since they react with water to form caustic hydroxides, they are irritating to the eyes, skin, and mucous membranes They also release a large amount of heat on reaction with the moisture of the skm See Industrial Data Sheet 462 and Hy gienic Guide Methanol (methyl alcohol) poisoning is usually produced by swallowing the liquid or inhaling high concentrations of vapor in an enclosed place such as a tank. The signs of poisonmg include headache, nausea, vom iting, violent abdominal pains, aimless and erratic movements, dilated pupils, sometimes delirium, and such eye symptoms as pain, tenderness on pressure, and occasionally blindness Direct action of the liquid or the vapor on the skin and mucous membranes may produce an irritation and inflammation One of the peculiarities of methanol poi sonmg is its exceptionally severe action on the optic nerve About one-half of all the senous cases of methanol poisoning result in some impairment of vision, which is usu ally permanent and may vary from dimness or blind spots scattered through the visual field to total blindness See Industrial Data Sheet 407 and- Hygientc Guide Methoxychlor (2^-di[p-methoxypbenyl]1,1,1-tnchloroetbane) is a synthetic insecti cide which is closely related to DDT m its action It is, however, about 1/8 to 1/10 as toxic as DDT Consequently, the hazard from inhalation of the dust or mist of sprays of this insecticide is remote. Methoxychlor is not absorbed through 40-40