Beryllium safety

Beryllium is added to copper to produce an alloy with greatly increased wear resistance it is used for current-carrying springs and non-sparking safety tools. It is also used as a neutron moderator and reflector in nuclear reactors. Much magnesium is used to prepare light nieial allo>s. other uses include the extraction of titanium (p. 370) and in the removal of oxygen and sulphur from steels calcium finds a similar use. 

Inhalation of certain fine dusts may constitute a health hazard. Eor example, exposure to siUca, asbestos, and beryllium oxide dusts over a period of time results ki the potential risk of lung disease. OSHA regulations specify the allowable levels of exposure to kigestible and respkable materials. Material Safety Data Sheets, OSHA form 20, available from manufacturers, provide information about hazards, precautions, and storage pertinent to specific refractory products. 

Table 12.1 shows that spring steel, the cheapest material listed, is adequate for this purpose, but has a worryingly small safety factor to allow for wear of the linings. Only the expensive beryllium-copper alloy, of all the metals shown, would give a significant safety factor (ctj,/ = 11.5 X 10 ). 

The combination of toxic hazard and high price (itself in part due to the extra measures needed in production processes to ensure the workers safety) has been an effective brake on commercial development of beryllium chemistry. Where possible substitute, albeit less effective, materials are often used titanium as an alternate lightweight metal or carbon fiber composites, phosphor-bronzes in place of beryllium alloys, aluminum nitride in place of BeO (1). 

The literature relating to the aqueous solution chemistry of beryllium has been covered to the end of 1998. Previous reviews and relevant compilations of data are listed in Table I. The scope of this review will be to consider all the published data, with a particular emphasis on quantitative aspects, with the aim of facilitating a general discussion. A brief section relating to health and safety issues will be found at the end. 

Although health and safety (317) and biochemical aspects (17) of beryllium are beyond the scope of this review, some reference must be made to toxicity hazards. Above all, inhalation of any beryllium-... 

National Institute for Occupational Safety and Health, US Department of Health, Education and Welfare Criteria for a Recommended Standard... Occupational Exposure to Beryllium, (NIOSH) Pub No 72-10268. 

The Occupational Safety and Health Administration several years later issued a proposed new occupational standard for beryllium air-counts. This proposal was highly controversial. 

The chemical and physical properties of each of these window materials vary widely. For example, polyimide is flexible, semitransparent, and chemically inert, but it has an upper working temperature of 673 K (for information about the properties of Kapton see http //www2.dupont. com/Kapton/en US / assets / downloads / pdf/ summaryofprop.pdf). Beryllium is stiff, has a low density, high thermal conductivity, and a moderate coefficient of thermal expansion it can be machined and is very stable mechanically and thermally. It also retains useful properties at both elevated and cryogenic temperatures. However, it does require a few safety-related handling requirements that are well documented (for detailed environmental safety and health information about beryllium see http //www.brushwellman.com). Nonetheless, as is stated in the Brush Wellman literature (for detailed environmental safety and health information about beryllium see http //www.brushwellman.com), "handling beryllium in solid form poses no special health risk."... 

The analysis has shown that the SRP s with beryllium reflector flooded with lead-bismuth alloy are the most dangerous from the point of view of nuclear safety. The main reasons that can cause Kgfr variation due to a positive reactivity are air voids (porosity) being present in the SRP s cores and the possibility for these voids to be filled with water, as water reactivity worth in the SRP s core is -0.7 Peff / L. Thus it means that about 30 Liters of water have to be accumulated for K ff to be - 1 in the core. 

SAFETY PROFILE Confirmed carcinogen. See also BERYLLIUM and BERYLLIUM COMPOUNDS. When heated to decomposition it emits very toxic fumes of BeO. 

SAFETY PROFILE Confirmed carcinogen with experimental carcinogenic, neoplastigenic, and tumorigenic data. A deadly poison by intravenous route. Human systemic effects by inhalation lung fibrosis, dyspnea, and weight loss. Human mutation data reported. See also BERYLLIUM COMPOUNDS. A moderate fire hazard in the form of dust or powder, or when exposed to flame or by spontaneous chemical reaction. Slight explosion hazard in the form of powder or dust. Incompatible with halocarbons. Reacts incandescently with fluorine or chlorine. Mixtures of the powder with CCU or trichloroethylene will flash or spark on impact. When heated to decomposition in air it emits very toxic fumes of BeO. Reacts with Li and P. 

SAFETY PROFILE Confirmed carcinogen with experimental mmorigenic data. Poison by ingestion and intraperitoneal routes. An experimental teratogen. Other experimental reproductive effects. Mutation data reported. When heated to decomposition it emits very toxic fumes of BeO and Cl". See also BERYLLIUM COMPOUNDS and CHLORIDES. 

SAFETY PROFILE Confirmed carcinogen. A dangerous fire hazard. When heated to 220°C it liberates explosive hydrogen gas. Reacts violently with methanol, water, and dilute acids. When heated to decomposition it emits toxic fumes of BeO. See BERYLLIUM COMPOUNDS and HYDRIDES. 

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