Because there are operational differences in exposure risks between beryllium metal and beryllium-containing alloys, the industry has categorized operations into low inhalation concern and operations having a likely inhalation hazard. The following table provides a summary of the processes used in beryllium metal processing (beryllium-containing alloys are treated later in this section), and groups them according to the inhalation hazard. It should be noted that most of the processes are only conducted outside the European Economic Area under strictly controlled conditions applying risk management measures as described in the table thereafter, and are given here to develop a comprehensive picture on operations performed in the beryllium industry.
The following exposure control measures must be considered for particle producing operations involving beryllium metal:
Machining Copper Beryllium Alloys
Drilling, Boring, Milling, Turning, Tapping, Reaming, Sawing, etc.
Copper beryllium is a ductile metal that machines easily, generally producing large chips and turnings. Processes that generate large particles are usually performed in an open shop environment with no special ventilation or housekeeping practices required. Machining processes that do generate small particles must be controlled with appropriate work practices and engineering controls. Best has prepared a Safety Bulletin “Safety Practices for Machining Copper Beryllium Alloys“. Additionally, a more detailed guide for machining copper beryllium alloys for use by end users is offered in “Guide to Machining Copper Beryllium“.
Sanding, grinding, buffing, lapping and polishing
These machining processes are capable of generating small particles. These processes must be controlled with appropriate work practices and engineering controls. BeST has prepared a Safety Bulletin “Safety Practices for Sanding, Grinding, Buffing, Lapping and Polishing Copper Beryllium Alloys” for use by end users. BeST has also prepared a case study report on benching operations (see “Case Study Benching CuBe Alloys“).
Stamping Copper Beryllium Alloys
Copper beryllium alloys are stamped into a variety of shapes, sizes and designs for use in electrical and electronic equipment. The manufacturing operations commonly associated with precision stamping can safely process copper beryllium alloys. The latest scientific evidence indicates that airborne beryllium exposure levels experienced at precision stamping operations are not sufficient to adversely affect health. Special controls are not required during the precision stamping, die repair, and inert atmosphere heat treating of copper beryllium alloys. Best has prepared a Safety Bulletin “Safety Practices for Precision Stamping Copper Beryllium Alloys” for use by end users. BeST also has developed a case study report on stamping (see “Case Study Precision Stamping CuBe Alloys“).
Welding (A Special Case)
Welding or cutting (with a gas flame or electric arc) indoors, outdoors, or in confined spaces, involving beryllium-containing base or filler metals must be done using local exhaust ventilation and airline respirators unless atmospheric tests under the most adverse conditions have established that the workers’ exposure is within the acceptable concentrations. In all cases, workers in the immediate vicinity of the welding or cutting operations shall be protected as necessary by local exhaust ventilation or airline respirators. BeST has prepared a Beryllium Safety Bulletin for safety practices for welding on copper beryllium alloys (see “Safety Practices for Welding Copper Beryllium“).
Casting and Alloying
Safe foundry practices must be employed when working with beryllium alloys. Furnace ventilation is required to capture fume and particulate generated during melting operations. The configuration and extent of ventilation must be designed for the specific application. One type of melting furnace, for example, may by its very design create little air contamination, while another may require more sophisticated engineering controls. Implicit in all foundry operations are the difficulties of handling molten metal and drosses plus the cutoff and finishing operations that are usually involved. BeST developed an overview of safety practices for copper beryllium foundry operations.
The importance of controlling airborne beryllium contaminant from drosses in an alloy foundry cannot be overlooked. Chemical analysis has shown that drosses frequently carry higher concentrations of beryllium than the alloys originally melted. Dross, moreover, is easily airborne, a characteristic which intensifies the need for appropriate management and control.
Ram Electrical Discharge Machining (EDM)
Ram EDM uses spark erosion to remove metal. When sufficient voltage is applied, the dielectric oil ionizes and controlled sparks melt and vaporize the work piece. As the metal melts and vaporizes, metal fumes are emitted. To control visible fuming and potential exposures, a properly designed ventilation system is recommended when conducting EDM on beryllium-containing alloys. BeST has developed a case study report on an EDM operation.
Computer Numerically Controlled (CNC) Lathe on Copper Beryllium Alloys
A CNC Lathe involves digitally automated machining of a rotating part mounted onto a chuck. CNC Lathe operations are generally performed in enclosed machining centers with a flooding of machining fluids. These machining centers allow for a variety of complex machining operations such as boring, turning, cutting, drilling and routing. The water soluble machining fluids are used to lubricate and cool the cut and to flush away the resulting swarf. This containment and flooding of swarf in the enclosed machining centers minimizes the release of particulate. BeST has developed a case study report on a CNC operation (see “Case Study CNC Lathe on CuBe Alloys“).
Enclosure doors should be interlocked to the machine controls. If the doors are opened, the machine should stop automatically. Ventilation systems should be interlocked to the machines in a manner which requires the ventilation to be operating before or concurrent to the start-up of the machines.
Workplace Exposure Characterization
Protective Clothing and Personal Hygiene
Within the European Economic Area, copper beryllium and nickel beryllium alloysare mostly stamped into a variety of shapes, sizes and designs for use in electrical and electronic equipment. The manufacturing operations commonly associated with precision stamping can safely process beryllium-containing alloys. The latest scientific evidence indicates that airborne beryllium exposure levels experienced at precision stamping operations are not sufficient to adversely affect health. Special controls are not required during the precision stamping, die repair and inert atmosphere heat treating of copper beryllium alloys. The following two tables provide a summary of those for copper beryllium and nickel beryllium alloy processes: