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Beryllium
Description: Pure beryllium (C.A.S. 7440-41-7) is a hard grayish metal, which occurs naturally as a chemical component of certain kinds of rocks. Two mineral rocks, bertrandite and beryl, are mined for the recovery of beryllium. Very pure gem-quality beryl is better known as either aquamarine or emerald. Most of the beryllium ore that is mined is processed into beryllium hydroxide, which is further processed into beryllium metal, alloys, and oxide. Pure beryllium metal is used to make aircraft disc brakes, nuclear weapons and reactors, aircraft-satellite-space vehicle structures and instruments, X-ray transmission windows, missile parts, fuel containers, precision instruments, rocket propellants, navigational systems, heat shields, and mirrors. Beryllium oxide is used to make specialty electrical and high-technology ceramics, electronic heat sinks, electrical insulators, microwave oven components, gyroscopes, military vehicle armor, rocket nozzles, and laser structural components. Beryllium alloys are used in electrical connectors and relays, springs, precision instruments, aircraft engine parts, nonsparking tools, submarine cable housings and pivots, wheels, and pinions. Chemical and physical properties: The beryllium compounds are beryllium chloride _ BeCl2, beryllium fluoride _ BeF2, beryllium oxide _ BeO, beryllium hydroxide _ Be(OH)2, beryllium phosphate _ Be3(PO4)2 3H20, beryllium nitrate _ Be(NO3)2, beryllium sulfate _ BeSO4, and beryllium carbonate Be(CO3)2 Be(OH)2. Beryllium chloride, fluoride, nitrate, phosphate, and sulfate are all soluble in water, while the other compounds are either insoluble or only slightly soluble. Beryllium and its compounds have no odor. Their flash points and flammability limits are unknown. Synonyms: Beryllium powder, berilio, en polvo (DOT SPANISH), beryllium atom, beryllium element, beryllium en poudre (DOT FRENCH), berryllium metal: beryllium, beryllium-9, and glucinium. Identification: Health effects: Inhalation of beryllium and its compounds is considered to have cancer-causing potential. But the effects of beryllium and its compounds are not well understood, and not all forms of beryllium are equally toxic. The lung is the main organ affected by inhalation of beryllium and beryllium compounds, and problems show up as acute pneumonitis or a more chronic form of lung disease, berylliosis (noncancerous growths in the lungs). Short-term exposure to beryllium compounds can lead to inflammation or reddening and swelling of the lungs, a condition known as Acute Beryllium Disease. Long-term exposure to beryllium or beryllium oxide at much lower levels has been reported to cause Chronic Beryllium Disease, with shortness of breath, scarring of the lungs, and berylliosis. Noncancerous growths that can ulcerate can form on the skin if beryllium enters cuts. Exposure Values: Regulation: Beryllium is regulated by OSHA and by EPA, under the Clean Air Act National Emission Standards for Hazardous Air Pollutants program (Section 112). Under Section 313 of the Emergency Planning and Community Right to Know Act of 1986, releases of more than one pound of beryllium into the air, water, and land must be reported annually and entered into the Toxic Release Inventory (TRI). Beryllium and its compounds are listed as toxic chemicals under the Emergency Planning and Community Right-to-Know Act of 1986; estimates of releases of beryllium and its compounds into air, water or land must be reported annually and entered into the national Toxic Release Inventory (TRI). National Overview of 1998 Toxics Release Inventory See EPA's Toxic Release Inventory. Notations: The NIOSH recommended exposure limits (RELs) are time-weighted average (TWA) concentrations for up to a 10-hour workday during a 40-hour workweek. A short-term exposure limit (STEL) is designated by "ST" preceding the value; unless noted otherwise, the STEL is a 15-minute TWA exposure that should not be exceeded at any time during a workday. A ceiling REL is designated by "C" preceding the value. Any substance that NIOSH considers to be a potential occupational carcinogen is designated by the notation "Ca." The OSHA permissible exposure limits (PEL) are found in Tables Z-1, Z-2, and Z-3 of the OSHA General Industry Air Contaminants Standard (29 CFR 1910.1000). Unless noted otherwise, PEL are TWA concentrations that must not be exceeded during any 8-hour workshift of a 40-hour workweek. A STEL is designated by "ST" preceding the value and is measured over a 15-minute period unless noted otherwise. OSHA ceiling concentrations (designated by "C" preceding the value) must not be exceeded during any part of the workday; if instantaneous monitoring is not feasible, the ceiling must be assessed as a 15-minute TWA exposure. In addition, there are a number of substances from Table Z-2 (e.g., beryllium, ethylene dibromide, etc.) that have PEL ceiling values that must not be exceeded except for specified excursions. For example, a "5-minute maximum peak in any 2 hours" means that a 5-minute exposure above the ceiling value, but never above the maximum peak, is allowed in any 2 hours during an 8-hour workday. Information Sources:
Originally published in Environment Writer by the National Safety Council. Reprinted with permission. Environment Writer Metcalf Institute for Marine and Environmental Reporting University of Rhode Island Graduate School of Oceanography Office of Marine Programs Narragansett, RI 02882 Tel: 401-874-6211; Fax: 401-874-6485 Disclaimer * Copyright 2002-2006 * All rights reserved. * University of Rhode Island |