Document b55Xag4b7By2omDwLgx3mp4KZ

ELEMENTS OF INDUSTRIAL TOXICOLOGY Magnesium is one of the light metals used possible to a dust separator which will re as a construction material In the early move the magnesium powder and trap it days of its industrial use, there were nu under water without permitting it to get merous laboratory reports that fine particles of magnesium, and particularly of magnesi um alloys, left in wounds would react with die tissue fluid to produce bubbles of hydro gen gas that would cause severe tissue in jury. It was stated that when the hydrogen was produced, magnesium hydroxide was also produced and acted as a moderately strong alkali to damage the tissue. This reaction is theoretically possible and has been produced m experimental animals by imbedding magnesium powder beneath the skin. It was also seen occasionally a number of years ago when metallic mag nesium dips were tned as substitutes for sutures m experimental surgery into the main exhaust system. The wet powder from these dust collectors and turn ing-chips that are wet with coolant should be removed from the plant as soon as they are taken from the collecting equipment Workers m magnesium-grinding opera, turns should be provided with and required to wear flame-resistant clothmg. Massive pieces of magnesium m the form of castings or machined work are not a se vere fire hazard because they are hard to ignite When once Ignited, however, the metal m the massive forms will burn vigor ously. See Industrial Data Sheet 426 and Hy gienic Guide Nevertheless, there are no published re ports of such tissue injuries from the in dustrial use of magnesium. The reason is not known, it may be that such injuries fail to develop or that the hazard is recognized and special care is taken to eliminate parti cles of the metal and its alloys from indus trial injuries The magnesium ion is a normal constitu ent of a number of tissues, and a certain amount of magnesium m die diet is essen tial to life. Excessive amounts are known to be toxic, and injuries and deaths due to medical use of magnesium salts have been reported. There have been no reports of in dustrial intoxication from inhalation of magnesium metal powder or magnesium oxide Inhalation of freshly produced magnesium oxide fumes has caused metal fume fever, cwntinr to the better known "zinc chills** or "zinc shakes'* caused by inhalation of fresh ly formed zinc oxide fumes. Heavy exposure to magnesium oxide is irritating to the eyes and nose and throat, but the material is not a severe primary irritant Finely powdered magnesium is a fire haz ard, and severe mjunes and deaths have occurred from lgmbon of powdered mag nesium m the dotting of workers who have done band grinding on magnesium alloys Also, fires and dust explosions have oc curred in exhaust systems carrying pow dered magnesium from grinding operations. Exhaust systems should go as directly as Malathion (O.O-rkmethyl dithiophosphata of diethyl mercaptosuccmate) is one of the organic phosphate insecticides. Like the oth ers of its class, its principal toxic action on warm-blooded animals is its inhibition of acetylcholinesterase. It seems to be one of toe least toxic of this type of insecticide Inhalation of S ppm (56 mg per cu m) by dogs and guinea pigs produced no effects except tears and a slight decrease in the Manganese is found m a wide variety of minerals. The dioxide is its most common inorganic compound and is used as a chemi cal intermediate, enamel additive, and drier. The probability of contracting manganese poisoning is low, but toe effects are severe --total disablement may result from a few months' exposure to high concentrations This effect, however, is more likely to oc cur after prolonged and repeated exposures above 30 mg per cu m The main hazard is usually horn the in halation of manganese dioxide, which, may produce neurological lesions The symp toms are many and are similar to Parkin son's syndrome. Symptoms include- weak ness, instability, difficulty in walking, im mobility of facial expression, monotonous and intermittent speech, spasmodic laughter, and other grotesque signs. Exposures to finely divided dusts of manganese dioxide may produce pneumonitis See Industrial Data Sheet 306 and Hy gienic Guide 40-39