Document 31BzX1Gg6qaVY90vYNB7xGdn

ELEMENTS OF INDUSTRIAL TOXICOLOGY enoe of water or moist air, forming hydro chloric acid, phosphorous acid, and pbosphonc acid and thus produce and burns Thor vapors are strongly irritating to the skin, mucous membranes, and respiratory system. Picric add (2,4,6-tnmtrophenol) is a yel low solid which, m the dry state, is highly sensitive to shock. It is therefore shipped with at least 10 per cent water m glass or wood containers It must also be kept out of contact with metals and ammonia to pre vent the formation of picrates more sensi tive to explosion than the picnc acid Containers should be plainly marked EXPLOSIVE-KEEP FIRE AND OPEN FLAMES AWAY, and the same notice should be posted at die doors of all rooms where the material is stored or used. The no smoking rale should be enforced m such areas, electrical installations should be ex plosion-proof m accordance with the regula tions of the National Fire Protection Asso ciation, and other sources of ignition, such as welding, must be controlled. Ficnc acid was once used extensively as a dressing for bums. This use has been large ly discontinued because many cases of skin irritation and systemic poisoning resulted from application of concentrations as low as 1 per cent to large areas of the skin. Picric sad is rapidly absorbed through the unbroken skin and even more rapidly through wounds, leading to headache, shiv ering, fever, and insomnia. Absorbed in larger quantities, it produces jaundice and severe inflammation of the kidneys Expo sure to the dust of picric acid may cause natation of the nose and throat, and espe cially of the eyes, leading to ulceration of the cornea See Industrial Data Sheet 351. Poison oak, poison ivy, and poison sumac are plant species whoso toxic irritant has been identified as tuushioL The dermatitis u the result of hyperaensitiartion to this compound. Individual susceptibility vanes greatly and also changes from time to tone, depending, at least in part, on how kmg it has been since the last exposure. No one is so completely immune, however, that a suf ficiently rigorous exposure will not result in dermatitis. Since reaotion to these plants is a byper- sensihzatfon, it seems logical that individu als could be desensitized by injections of graduated doses of die punfied extract This has been attempted m many instances, and there are a number of extracts on the mar ket for the purpose They seem to give some limited protection to sensitive indi viduals. Statistics from field trials, even from those well satisfied with the protec tion provided, are nut impressive. Limited proteo&on is also given by a number of protective creams containing oxidixmg materials such as sodium perborate The principle of these creams is based on the fact that urushiol can be gradually oxi dized to an inert black product Thor suc cess is limited by the fact that the oxidation is slow at best One of the most effective materials for destroying the poison is feme chkmde, but it is apt to permanently dis color the skm to which it is applied. The poisoning can most effectively be prevented by destruction of the plaids with one or two applications of a herbicide such as one of the 2,4-D formulations. Destroy ing them by grabbing out and burning is both expensive and hazardous for die men doing the work and is no more effective than application of the herbicide See Industrial Data Sheet 304. Potassium chlorate--see Sodium chlorate. Potassium cyanide--see Sodium cyanide. Potassium hydroxide is a white solid ex tremely soluble in water It is most common ly furnished as a concentrated solution in tank-car quantities and as the solid m flakes, pellets, and sticks, or cast solid in glass or m metal drums. The most common mjunes suffered with potassium hydroxide are burns of the skm or eyes, caused by solid particles and splashing of the concentrated solution from attempts to dissolve the solid in hot water The solid alkali generates so much heat on dissolving that there is often local boilmg even when cold water is used To dissolve the material from a drum m which it is cast solid, the drum should be suspended near the top of a tank of luke warm water so that the water can circulate through the drum The high density of the cancentr&ed solution will promote circula tion from the top to the bottom of the tank. This method will provide both faster sole- 4f\ 4*\