Mg shaving

Mg ribbon and fine Mg shavings can be ignited at air temps of about 950°F (Ref 26). Oxides of Be, Cd, Hg, Mo and Zn can react explosively with Mg when heated (Ref 8). Mg reacts with incandescence when heated with the cyanides of Cd, Co, Cu,Pb, Ni or Zn or with Ca carbide (Ref 9). It is spontaneously flam-mable when exposed to moist chlorine (Ref 10), and on contact with chloroform, methyl chloride (or mixts of both), an expl occurs (Ref 4). Mg also reacts violently with chlorinated hydrocarbons, nitrogen tetroxide and A1 chloride (Ref 14). The reduction of heated cupric oxide by admixed Mg is accompanied by incandescence and an expin (Ref 7).Mg exposed to moist fluorine is spontaneously flammable (Ref 11). When a mixt of Mg and Ca carbonate is heated in a current of hydrogen, a violent ex pin occurs (Ref 12). When Mo trioxide is heated with molten Mg, a violent detonation occurs (Ref 1). Liq oxygen (LOX) gives a detonable mixt when... 

NG wax and was of yellow color. The 3rd chge was light-brown in color and consisted of RDX with a desensitizing agent. Mg shavings (1-3 oz per 1 lb of HE) were added to all above demolition chges to increase their incendiary effect... 

The purpose of this operation is not to release ethylene but to etch the Mg shavings. 

Aryl bromides can be converted to aryl Grignard or aryllithium compounds in three ways (Figure 5.41). In the first two methods, the aryl bromide is reacted with Mg shavings or with Li wire, respectively (see Section 17.4.1 for the mechanism). In the third method—which is especially convenient for small-scale preparations—aryl bromides are converted into aryllithium compounds either with 1 equivalent of butyllithium (w-BuLi) or with 2 equivalents of fert-butyllithium (terf-BuLi) by the so-called Br/Li exchange reaction. 

In an elongated flask of a Pyrex apparatus, pre-evacuated to 10" mm., 20 g. of Dg,0 is slowly evaporated. The vapor passes through the reaction tube, set vertically on top of the flask. The tube (I.D. 2.4 cm. and 55 cm. long) contains 130 g. of Mg shavings of various sizes, with coarse particles on the bottom and loose powder on top. The colmnn filling is si iported by a perforated platinum disk which rests on glass lugs inside the tube. The Mg is heated to 480°C by a tubular furnace. 

An identical two-neck flask is used for the preparation of the CgHgMgBr solution. However the second neck carries a dropping funnel for the addition of CgHgBr instead of a gas inlet tube. About 136 g. of CgHgBr is needed for the conversion of 24.5 g. of Mg shavings. 

Type I Mg powder shall consist of shavings, turnings, flakes, plates or any combination of these which meets the granulation requirement. Type II Mg powder shall consist of oblong chip-like particles with rounded edges. Type III Mg powder shall consist of granular or spheroidal particles... 

LD50 values for the dermal route of exposure to methyl parathion have been established in acute studies for rats 67 mg/kg for males and females (Gaines 1960), 110 mg/kg for males, and 120 mg/kg for females (EPA 1978e). The LD50 in male mice exposed by dermal application of methyl parathion to their hind feet (rather than shaved backs) was 1,200 mg/kg (Skinner and Kilgore 1982a). The mice were muzzled to prevent oral exposure from grooming. 

Experiments were conducted in which purified trichloroethylene (1 mg in acetone) was applied to the shaved backs of female ICR/Ha Swiss mice (Van Duuren et al. 1979). In an initiation-promotion study, a single application of trichloroethylene was followed by repeated application of phorbol myristate acetate (PMA) promoter. In a second study, mice were treated with trichloroethylene three times per week without a promoter. No significant tumor incidences were observed in these studies. Doses used in these studies were well below the maximum tolerated dose, which is often not reached in dermal studies. 

Some dermal uptake of diisopropyl methylphosphonate through the skin of rabbits can be inferred based on the death of 3 of 4 animals treated with 2,000 mg/kg neat applied to shaved abraded or unabraded skin for a 24-hour period (Hart 1976). 

To evolve H2 for measurement of D/H burn 5 mg dry sawdust in 1 atm. 02 in a cupric oxide furnace at 750 °C. Use oxygen purified over silica gel and cupric oxide to ensure that the 02 is hydrogen free. Freeze out H20 and C02 in a liquid oxygen trap. Release C02 at dry ice temperature. React H20 vapor on clean uranium shavings at 950 °C, thus producing H2 quantitatively. 

Raised over wood shavings containing 134 mg PCP/kg for 9 weeks... 

Adult females and weaned juveniles of both sexes held in outdoor flight enclosures roost boxes treated with 69,300 mg PCP/kg and wood shavings contained 65,000 mg/kg FW All dead within 24 h (90% survival in controls after 32 days). Carcasses of dead bats had 13.1 mg PCP/kg FW. Total PCP burden, in pg, ranged from 17-152 in whole body and 29-181 in fur. Maximum tissue concentrations, in pg/kg FW, were 99 in fat, 65 in liver, 25 in kidney, and 30 in remainder (Shore et al. 1991)... 

Hexachloroethane had no effects on intact or abraded skin of rabbits when 500 mg was applied to shaved skin as the pure solid (Weeks et al. 1979). There was only a slight redness at the application site when it was applied as a water paste. All redness disappeared after 72 hours. The NOAEL for dermal effects in rabbits (132 mg/kg) is reported in Table 2-3. 

Median Lethal Dosage, Animals LD50 (monkey, percutaneous) = 9.3 mg/kg (shaved skin) LCt50 (monkey, inhalation) = 187 mg-min/m3 (t = 10)... 

No studies were located regarding reproductive effects in animals after dermal exposure to mirex. The only animal study that referred to reproductive effects following dermal exposure to chlordecone was conducted in rabbits by Allied Chemical. This study was not available for review. A published review of the study (Epstein 1978) indicated that chlordecone applied to shaved skin at dose levels of 5 or 10 mg/kg for 8 hours/day, 5 days/week, for 3 weeks induced testicular atrophy in two of six rabbits at 5 mg/kg and in one of six rabbits at 10 mg/kg. No other toxic effects were noted. This study is limited by the lack of dose response and lack of a NOAEL for the effect observed. 

A dermal absorption rate of 329 mnol/minute/cm ( 60 nmol/minute/cm ) was calculated for the shaved abdominal skin of mice (Tsumta 1975). This is equivalent to a human absorption rate of 29.7 mg/minute, assuming that a pair of hands are immersed in liquid chloroform (Tsumta 1975). However, this calculation was based on the assumptions that the rate of chloroform penetration is uniform for all kinds of skin and that the total surface area of a pair of human hands is 800 cm the former assumption is especially dubious. Islam et al. (1995) investigated the fate of topically applied chloroform in male hairless rats. For exposures under 4 minutes, chloroform-laden water was applied to shaved back skin for exposures of 4-30 minutes, rats were submerged in baths containing chloroform-laden water. Selected skin areas were tape-stripped a various number of times after various delay periods. It appeared that there was an incremental build-up of chloroform in the skin over the first four minutes. When compared to uptake measured by bath concentration differences, approximately 88% of lost chloroform was not accounted for in the stratum comeum and was assumed to be systemically absorbed. 

Acute intoxication of guinea pigs, exposed orally (0.25ml/day), percutaneously (by application to 6 cm of shaved skin), or by inhalation (1.42 mg/1 for 8 hours/day), produced loss of weight, tremors, paralysis of the hindquarters, and difficult respiration. ... 

During the 14 day observation period some rabbits (2-8) died after 8-hour exposure to doses of 775-1,550 mg/kg applied directly to shaved skin (3.2 cm, but no deaths occurred in the 388 mg/kg dose group. The author calculated an LD o of 1,116 mg/kg from these data (Duprat and Gradiski 1978). Central nervous system depression was evident, as manifested by stupor. Some animals were weak and anorexic, while others showed signs of dyspnea and cyanosis. The lungs, liver, and kidneys were congested in animals that died. Death was reportedly due to respiratory or cardiac failure. 

Rabbits exposed to doses of 388-1,550 mg/kg applied to shaved skin exhibited evidence of aneral nervous system depression (stupor) during exposure and in the 1 -2 hour period after exposure (Duprat and Gradiski 1978). 

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