Where exposures remain elevated, increasing the air flow rate through openings in the ventilated enclosures from 250 fpm to 400 fpm will offer an additional benefit. Even partially ventilated enclosures with ventilation of 400 fpm routinely reduce exposure levels to 0.2 ug/m[3] or less for workers using a wide range of equipment in various industries (Materion Corp-meeting, 2012).  Other ventilation-related changes are also options for reducing shakeout operator exposures under special circumstances. A foundry visited by NIOSH found that reducing cross-currents caused by man-cooling fans and using a foundry ventilation system as designed reduced the dust exposure levels of shakeout operators by 50 percent. Computer models predicted that a substantial additional reduction (over 75 percent) could be achieved by renovating the existing shakeout area ventilation system in a foundry producing very large castings (NIOSH EPHB 233-133c).
Shakeout Operator -- Conclusion
The exposure profile for shake out operators contains only one sample of 1.3 ug/m[3], which indicates that shakeout operators will require additional controls.  NIOSH reported measuring a maximum concentration of 0.42 ug/m[3] for a group of workers that included a shakeout operator, however, the sample directly associated with the shakeout operator was not identified (NIOSH EPHB 326-16a).  Additionally, the six samples in the IMIS data from two different foundries range from 0.05 ug/m3 to 0.5 ug/m[3], with a mean of 0.22 ug/m[3] and a median of 0.11 ug/m[3].  The result of 0.42 ug/m[3] reported by NIOSH is consistent with the IMIS sample results for shakeout operators, and therefore more likely to be representative for this job category.  Recommendations for control measures provided in the NIOSH report suggest that the exposure level of shakeout operators can be held to a level of 0.42 ug/m[3] or less by rudimentary improvements in the function and maintenance of existing shakeout area ventilation (NIOSH EPHB 326-11a). When comparing this value of 0.42 ug/m[3] obtained by NIOSH in a facility with rudimentary controls to the baseline value of 1.3 ug/m[3], OHSA notes that exposures for shakeout operators can be significantly reduced when compared to the exposure associated with baseline conditions (ERG Silica_GenInd1v.2, 2008).
Irwin (2003) reported that enclosure, significant ventilation system improvements, addition of a media tumbler, and housekeeping measures reduced the respirable dust exposure levels of a shakeout operator by 81 percent. If beryllium contained in the dust is captured to an equal extent, then additional controls to reduce dust levels in the shakeout operation could reduce the beryllium levels for the most highly exposed shakeout operators by as much as 80 percent.  A reduction of 80% to the industry profile value of 1.3 ug/m[3] would result in a value of 0.25 ug/m[3], and the estimate from the supplemental data of 0.42 ug/m[3] would be reduced to 0.08 ug/m[3].
OSHA preliminarily concludes that the proposed PEL of 0.2 ug/m[3] can be achieved for some shakeout operators, but additional information on the range of current exposures and the effectiveness of existing dust controls for shakeout operations is needed to determine whether the proposed PEL can be achieved in most operations most of the time.
Abrasive Blasting Operator
Abrasive Blasting Operator -- Baseline Controls
The exposure profile for abrasive blasting operators is based on five PBZ results for workers abrasively blasting on foundry castings during repair work performed on the castings (at a facility that routinely refurbished the cast shapes). The exposure levels measured range from 0.05 ug/m[3] to 0.15 ug/m[3]. Although the employees associated with the results in the exposure profile used enclosed and ventilated equipment that was only minimally automated (the employees had to transfer abrasive media back into the system hopper manually after use), abrasive blasting operators in foundries typically use enclosed and ventilated blasting units or other surface preparation machines that are partially or fully automated, which could potentially result in lower exposures than those summarized in the exposure profile if the abrasive blasting equipment is well maintained. However, ERG's analysis of crystalline silica in foundries suggested that blasting machines are typically poorly maintained, incompletely sealed, and associated with inefficient ventilation systems (ERG Silica_GenInd1v.2, 2008). And as described above for molders, cross-contamination can be an additional source of exposure. Abrasive blasting operations are often located near the pouring and shakeout areas. Air contaminants in any adjacent areas (whether originating in or migrating through the spaces) can also spread through the abrasive blasting operator work area, contributing to the exposure of workers in this job category.
Abrasive Blasting Operator -- Additional Controls
The somewhat limited exposure profile (five values from one facility with a median of 0.11 ug/m[3]) indicates that abrasive blasting operators are typically exposed to levels below 0.2 ug/m[3].  Additional data from IMIS suggest that sample results exceed 0.1 by a modest amount (e.g., two of three positive IMIS results were 0.101 ug/m[3]). Cross-contamination between foundry areas can contribute to workers' exposure levels. Elimination of cross-contamination (by balancing all supply and exhaust air systems) should also reduce airborne contamination from other foundry areas as a source of beryllium exposure for workers in the abrasive blasting area, allowing these workers to achieve exposure results of 0.1 ug/m[3] or less.
Although they do not appear to be necessary in most foundries that cast beryllium alloys, a number of additional control methods are available for abrasive blasting operators.
Improve Existing Blasting and Surface Preparation Machines
A primary control for abrasive blasting operators involves repairing or improving the machines that they control to seal leaks, and augmenting ventilation systems to achieve 500 fpm air flow through all openings (see VS-80-02 in ACGIH, 2010; Pangborn, 2003).
A wide range of abrasive media are available for use in surface preparation machines. Some media can themselves be a source of additional beryllium exposure (due to their own beryllium content) or can contain other toxic substances (e.g., crystalline silica, other metals) (KTA-Tater-Phase-I, 1998). Employers must evaluate any surface preparation media prior to use and ensure workers are adequately protected from all associated hazards (OSH Act, 1970).
Sealed Blasting and Surface Preparation Machines
To minimize beryllium exposure levels, foundries can select airtight, batch-style blasting and surface preparation machines, with a door that seals closed. The modest leakage that might occur from continuous blasting machines (parts constantly conveyed in and out of the machine though openings in the machine) might prevent abrasive blasting operators from achieving the lowest levels (e.g., exposure levels less than 0.1 ug/m[3]).  However, a well-functioning, completely sealed blasting machine could be expected to reduce exposures to that value or lower. An important feature of a fully enclosed and ventilated blasting or other surface preparation machine (or blast cabinet) is an interlock that prevents the machine door from being opened until the ventilation system has had a chance to remove dusty air from the unit.
To achieve the lowest exposure levels, OSHA believes that it will also be necessary to control dust release during transport of castings to and away from blasting or surface preparation machines. To this end, conveyers, containers, and other equipment used to transport castings to the machines should be enclosed and any openings exhausted with LEV. After blasting with abrasive media, castings and the interior of the machine should be wiped to remove dust from surfaces (similar techniques are used to minimize dust from machining operations; see Section 3 -- Beryllium Production Exposure Profile and Technological Feasibility Analysis and Section 7 --  Precision Turned Products).
Additionally, employers should be aware that beryllium dust can become a source of beryllium exposure for abrasive blasting operators when they use a leaking blasting machine. And in addition to maintaining blasting machines so they function as intended, machines that clean the abrasive media between cycles, and operating procedures that promote the standard practice of replacing all or part of the media on a routine basis, will both help minimize the buildup of beryllium dust in the abrasive blasting media.
In the series of industrial hygiene surveys during which the exposure profile data were obtained, Materion Corporation evaluated abrasive blasting of the castings in glove-box-type ventilated blasting cabinets at a facility where the castings are periodically abrasively blasted with aluminum oxide or steel shot during repair (MC Pkg I-D, 2010). Five full-shift samples for abrasive blasting operators ranged from 0.05 ug/m3 to 0.15 ug/m[3], with no improvement (in the already modest exposure levels) recorded after the blast cabinets were centralized and ducts redesigned.  After this period of system modification, the investigator reported on the characteristics for the abrasive blasting cabinets as follows:
Average inlet area air velocity 482 fpm to 1,194 fpm.
Five to 10 air changes per minute in the cabinet interior.
80 cfm to 131 cfm air flow.
Duct transport velocity 4,000 fpm.
Connected to a centralized dust collection system.
Service and maintain abrasive blasting cabinets on an ongoing basis.
Additional recommendations suggested there was still some room for improvement in the system and work practices. The recommendations noted that:
Dust should not fall from the doors when they are opened.
Gloves of the abrasive blasting cabinets need to be replaced when they get worn, are torn, or have holes in them.
Install interlocks to require at least air changes of the enclosed volume before the operator is permitted to open the cabinet after abrasive blasting tasks.
Use a HEPA filter vacuum on the floor if it becomes dusty.
Evaluate worker exposure with air sampling to confirm that the cabinet is working properly and protecting workers from excessive exposure.
During abrasive blasting, until air monitoring confirms that the abrasive blasting cabinet controls worker exposure to the accepted level, use NIOSH-approved respiratory protection covered by a fully implemented respiratory protection program in accordance with OSHA's Respiratory Protection standard (29 CFR 1910.134).
Numerous models of sealed, ventilated blast cabinets and related surface preparation machines are commercially available. One manufacturer of blast cabinets and related equipment recommends 150 cfm of air suction for a 12-inch (diameter) cylindrical tumble blast cabinet and up to 1,800 cfm air suction for a 48-inch unit (Clemco-tumble, 2007). The same manufacturer provides air suction and filtration equipment for blasting and surface preparation equipment, each fitted with primary filters and optional secondary HEPA filters (Clemco, 2011). For toxic dust applications in facilities that handle beryllium, these units can be fitted with pressure and airflow sensors to confirm continuous effective function, and bag-in-bag-out systems that help protect workers changing the filters (Clemco, 2011).
Isolating Booths
Isolating booths that separate the worker from the casting are a control option for manual abrasive blasting of small and large castings. For small castings, a well-enclosed, ventilated glove-box-style blasting cabinet would serve the purpose. For long castings, available options include linking glove boxes or glove-style pressure blasting cabinets. For example, at least two manufacturers produce ventilated cabinets with internal working compartment dimensions at least 5 feet wide and 40 inches deep (Pauli RAM 31, 2001; Pauli SSPC, 2001; Clemco, 2007). These boxes can be interlocked to prevent operation unless the unit is sealed. In addition, a time delay feature can also prevent operators from opening doors for a pre-set number of seconds, until the vacuum suction has had a chance to remove dust from the cabinet interior (at a ventilation rate of 840 cfm to 900 cfm, depending on the model). Finally, the boxes can be fitted with HEPA dust collectors and completely enclosed, ventilated media reclamation systems. A larger ventilation system is needed when two or more of these double-wide cabinets are linked together to provide a larger internal workspace (Pauli SSPC, 2001).
Castings that are larger in more than one dimension would require a larger, less effective alternative. Abrasive blast booths that include an incompletely sealed partition to separate the operator from the blasting activity, such as roll-up doors with an access slot and window, will provide an additional level of protection if negative pressure is maintained in the blasting enclosure. This type of equipment is commercially available and used by two granite-working facilities in which NIOSH conducted control technology assessments (NIOSH ECTB 233-106c; NIOSH EPHB 233-131c). However, NIOSH reported mixed results in these booths' ability to control silica exposures. Air pressure and turbulence introduced during blasting may limit the reliability of this control option.
Wet Abrasive Blasting and Surface Preparation
Wet abrasive blasting or water-jetting methods (adding water to the blasting solution or blasting with high-pressure water) offer additional control options for both small and large non-ferrous castings. Use of wet methods can significantly reduce airborne dust during surface cleaning (SSPC, 2001). A report prepared for the U.S. Army National Guard (presenting U.S. Naval Yard Study results) compares various wet and dry abrasive blasting methods and the frequency with which heavy metal PELs were exceeded (Industrial Hygiene West, 2000). Air sampling suggested that workers had a 33 to 44 percent risk of exceeding the PELs for lead (50 ug/m[3]) or cadmium (5 ug/m[3]) when using dry blasting methods (open abrasive blasting and blasting inside a blasting enclosure). In contrast, limited sample results for workers using low-volume water slurry blasting (steel shot with water added) and high-pressure water jetting without abrasive added indicated the risk of exceeding the lead or cadmium PEL was between 0 percent and 3 percent.
Reduce Beryllium Oxide on Castings
Reducing beryllium oxide formation on casting surfaces is an additional option for reducing the beryllium exposure of abrasive blasting operators. Foundry efficiency is increased by casting methods that reduce blemishes and imperfections, such as oxides, which must later be removed from castings. Additionally, because most oxide on the casting will be removed during blasting, and because alloy oxide often has greater beryllium content than the base metal, reducing oxide formation might have a notable effect on blasting operator exposure.
Casting methods to minimize oxide formation include those that minimize the contact of oxygen in the air with the hot metal surface, such as permanent mold or die casting. Methods such as direct chill casting that cool the casting rapidly to reduce surface temperatures to a level at which oxide does not form as quickly are particularly effective. One casting facility visited by NIOSH, a secondary smelter that also cast copper anodes, sprayed and submerged red-hot castings in water to cool them as quickly as possible (NIOSH HETA 82-024-1428).
The benefit of reducing surface oxide as a method for reducing abrasive blasting operator exposure levels has not been quantified for beryllium; however, reducing the amount of friable contaminant-bearing coatings will reduce the extent to which these materials are dislodged during abrasive blasting. In the case of beryllium alloy castings, the base metal would continue to be a source of exposure for blasting operators; however, the highly friable and higher-beryllium-content oxide would be eliminated as a source of airborne exposure if removed by pre-cleaning.
Abrasive Blasting Operator -- Conclusion
Based on  five sample results ranging from 0.05 ug/m[3] to 0.15 ug/m[3], supported by IMIS results of 0.02 ug/m3 to 0.101 ug/m[3], OSHA finds that exposure levels of 0.2 ug/m[3] have already been achieved for most abrasive blasting operators through use of well-sealed, completely enclosed, ventilated abrasive blasting cabinets. As a result, OSHA preliminarily concludes that the proposed PEL of 0.2 ug/m[3] can be achieved for most abrasive blasting operators most of the time through this control.
Additionally, any excessive beryllium exposure due to cross-contamination or secondary exposure from activities of workers in other job categories will be reduced when the other workers' exposures are reduced to 0.2 ug/m[3], or alternatively, when cross-contamination by air currents is eliminated by balancing all supply and exhaust air systems. Exposures will also be reduced if employers use wet methods, or reduce beryllium oxide on castings.  OSHA estimates that these additional controls will be adequate to further reduce the exposure of most abrasive blasting operators to an alternative PEL of 0.1 ug/m[3].
Grinding/Finishing Operator
Grinding/Finishing Operator -- Baseline Controls
Grinding, sanding, cutting, and polishing of aluminum and copper castings are commonly performed in enclosures as a wet process or with LEV. Enclosures with wet methods or LEV were generally used with the finishing operations at the copper-beryllium casting facilities visited by NIOSH (NIOSH EPHB 326-11a; NIOSH EPHB 326-16a). Housekeeping in and around the grinding/finishing workstation, however, is not always thorough or performed consistently.
Wet methods were used frequently at the foundry that ERG visited (ERG Beryllium Site 7, 2003). The material handler, who worked in all areas of the foundry over the abbreviated work shift, used a band saw briefly to trim larger castings prior to shipment. No corresponding exposure results were collected because no worker was dedicated to this task at that small foundry. Although no use of LEV was reported for this task, ERG noted that the band saw was designed with an option for wet cutting using a lubricant stream and that the investigator recommended that the area around the saw should be covered with absorbent mats. This suggests that the floor was wet and that at least some, if not all, of the cutting that day was performed as a wet process.
At one of the beryllium alloy foundries visited by NIOSH, the employer reportedly conducted all cutting and grinding operations in partially enclosed booths equipped with LEV (NIOSH EPHB 326-16a). However, a photograph of the cutting and grinding shop shows that in addition to the two partially enclosed booths with LEV, the shop also contained two finishing work stations where only LEV is used for control, with no partially enclosed booths around the equipment. Six full-shift PBZ samples were obtained in the cutting and grinding shop with the following results: 0.10 ug/m[3], 0.23 ug/m[3], 0.27 ug/m[3], 0.29 ug/m[3], 0.44 ug/m[3], and 1.07 ug/m[3]. No information was provided describing the circumstances associated with these results. LEV was also available to all employees conducting grinding and finishing operations at the castings refurbishing facility (highest exposure 0.9 ug/m[3]). After initial exposure measurements were made with user-positioned duct/hood combinations, the workstations were redesigned with more reliable benchtop backdraft-downdraft booths (highest exposure 0.06 ug/m[3]) (MC Pkg I-D, 2010).
At the other alloy foundry that NIOSH visited, grinding/finishing operators used a combination of automation, enclosures, and wet methods (NIOSH EPHB 326-11a). There, castings were sent to the machine shop for "machining, grinding, polishing, and buffing." NIOSH reported that workers placed parts into enclosed automated lathes and used cutting fluids to control and contain the release of metal particles.
Grinding/Finishing Operator -- Additional Controls
The exposure profile for grinding/finishing operators is described by a median exposure level of 0.05 ug/m[3]. Based on the profile presented in Tables IV-29 and IV-30, 58.9 percent of grinding/finishing operators currently have exposures less than 0.1 and another 14.3 percent of sample results range from 0.1 ug/m[3] to 0.2 ug/m[3]. The exposure profile indicates that most grinding/finishing operators already experience exposures of 0.2 or less; however, additional controls will be required to reduce the exposures for the remaining 26.8 percent to this level. Additional control options for grinding/finishing operators include LEV, full or partial enclosures, wet methods, and eliminating or minimizing work practices that increase exposure. In some cases, existing ventilated enclosures may need to be more fully enclosed to improve the efficiency of the LEV.
LEV and Enclosures
For manual grinding tasks, regardless of the nature of the industry, Materion Corporation suggests a booth designed with both backdraft and downdraft exhaust ventilation inside the partial enclosure (Materion Information Meeting, 2012). For example, such a booth would include a front opening and rear exhaust as is available for abrasive cut-off saws (Figure VS-80-17 in ACGIH, 2010), and the downdraft table ventilation of a hand-grinding bench (Figure VS-80-18 in ACGIH-Ch13, 2010). An adaptation to provide a rear-slot exhaust (rather than plain rear takeoff) is preferable for hand grinding, which might not occur at a single fixed spot inside the booth. The booth exhaust should provide 250 fpm across the opening and be fitted with a HEPA air filter; special precautions such as respiratory protection must be used when servicing the booth or blower and changing the filter. The booth should also be equipped with alarms to indicate when filter performance falls outside an effective range. According to Materion Corporation, if this booth design does not sufficiently control exposures, the booth can be redesigned to achieve lower exposure levels by increasing the ventilation rate to provide 400 fpm across openings, a strategy that has proven successful for a variety of hood designs at Materion Corporation's plants and those of its customers (Materion Information Meeting, 2012).
Materion Corporation advocates grinding booths of this general backdraft-plus-downdraft design, paired with work practice controls and careful housekeeping methods, as an effective method for reducing exposure levels for workers performing manual grinding (and related tasks using powered or rotary tools, such as polishing and buffing) to concentrations of 0.2 ug/m[3] or less (Materion Information Meeting, 2012). The control measures (i.e., engineering controls, work practice controls, and housekeeping) must be used together to ensure that exposure levels are reliably maintained at or below 0.2 ug/m[3] most of the time for grinding and finishing operations. Materion Corporation's exposure reduction guidelines are generic and applicable to any industry where beryllium-containing particles are generated using powered or rotary hand tools. Thus, these guidelines apply to foundries and machining facilities in the same manner as they apply to other types of facilities.
In addition to improving LEV, employee training should be augmented to ensure that all employees use engineering controls properly and routinely. Housekeeping in facilities that use beryllium alloys should be performed routinely and thoroughly to prevent the accumulation of dust that can be spread to other work areas or become airborne if disturbed. Cleaning should be performed with HEPA vacuums instead of traditional vacuums, and the use of compressed air and dry sweeping should be prohibited.  With this standard group of controls, the grinding bench will control the exposures of grinding/finishing operators while they manually grind beryllium alloy castings, and work practice and administrative controls are necessary to ensure that the bench ventilation is maintained in working order and kept clean, and that beryllium particles are not released when the ventilation system is serviced and the filter is changed.
Although no study demonstrates the effectiveness of these controls in foundries, several studies provide evidence that ventilation systems in combination with work practices that enhance the effectiveness of  the ventilation systems can reduce worker exposure levels substantially in establishments where the grinding/finishing work is substantially similar to work that otherwise could be performed in a foundry. This information was obtained from Materion Corporation's exposure reduction guidelines, and they are generic and applicable to any industry where beryllium-containing particles are generated using powered or rotary hand tools. Thus, these guidelines pertain equally to foundries as they do to other types of facilities.
The value of well-designed ventilation controls and associated work practices is demonstrated particularly well by a series of industrial hygiene surveys conducted by Materion Corporation in plants that work with beryllium alloy objects (including foundry-cast dies designed for casting other products such as plastics) (MC Pkg I-D, 2010; also summarized in Materion PSCS 105, 2011). In the industrial hygiene surveys, the investigator measured full-shift PBZ exposure levels before and after interventions for workers performing grinding at a bench (called "benching") using hand-held pneumatic grinding tools. Although the grinding operations did not take place in foundries, they are typical of grinding activities that are performed in foundries; both activities involve the same beryllium alloy castings, the same grinding tools, and the same objective of removing defects and excess metal as part of a finishing process (MC Pkg I-D, 2010).
As presented in Table IV-32, 17 grinder operators initially experienced exposure levels ranging from 0.01 ug/m[3] to 0.9 ug/m[3] while using downdraft or user-positioned exhaust trunk ventilation. After additional controls were implemented, results from 23 samples indicated that exposures were reduced to a range of 0.01 ug/m[3] to 0.06 ug/m[3], representing a 94 percent reduction in the maximum exposure level compared to exposure levels measured while workers used the less effective ventilation systems originally in place (MC Pkg I-D, 2010). The additional controls used to achieve this reduction included a benchtop booth (enclosing the top, back, and sides of the work area, with an open front through which the worker reached) installed over a downdraft-backdraft table. Other improvements included improved lighting, a work practice "to allow the worker to see well, reducing the need to be in close proximity to the part," duct transport velocities of 4,000 fpm to prevent particles from settling in the ducts, and "a single power switch, turning on lighting, all pneumatic and electric power, and opening the hood blast gate." The tools would not operate if the blast gate was not open . Additionally, due to its variable-drive fan motor, the dust collection system was able to increase air flow when more hoods were in use -- maintaining a more consistent air flow rate for all workstations, regardless of the number of workstations operating at one time. Removable plates made it easier to clean the downdraft plenum and the entire hood tilted to improve access to the part being worked (MC Pkg I-D, 2010). Ventilated bench top grinders could be placed within a similar hood to offer an added level of worker protection.
Table IV-32 -- Summary of Personal Exposure for Grinding/Finishing Operators Working on Beryllium Alloy Under Various Conditions
Job Category
                             Total Number Samples
                                     Range
                                  (μg/m[3])
                                     Mean
                                  (μg/m[3])
                               Median (μg/m[3])
	Grinding/finishing -- user-positioned duct*
                                      17
                                  0.01 to 0.9
                                     0.18
                                     0.05
	Grinding/finishing -- backdraft/downdraft hood*
                                      23
                                 0.01 to 0.06
                                     0.03
                                     0.02
	Grinding/finishing -- Other
                                      16
                                  0.1 to 4.79
                                     0.86
                                     0.27
Grinding/finishing operator -- Total
                                      56
                                 0.01 to 4.79
                                     0.31
                                     0.05
No samples for workers using backdraft/downdraft hoods exceeded 0.2 μg/m[3] and all were also less than 0.1 μg/m[3]. Among the group using user-positioned ducts: 5 of 17 samples (29 percent) exceed 0.2 μg/m[3].  Within the group working under other (undefined) conditions, 10 of 16 samples (63 percent) exceeded 0.2 μg/m[3].

*	Originally, the exposure profile consisted of 16 samples. Materion provided OSHA with these additional samples that have been incorporated into the exposure profile.

Source: CCMA, 2000; NIOSH HHE 75-87-280; NIOSH EPHB 326-11a; NIOSH EPHB 326-16a; *Materion Pkg  - D, 2010.

At a beryllium machine shop ERG visited (ERG Beryllium Site 1, 2002), all machining operations are fully enclosed and ventilated. Six full-shift PBZ samples obtained on machinists ranged from 0.02 ug/m3 to 0.11 ug/m[3], with a mean of 0.035 ug/m[3] and median of 0.02 ug/m[3]. At another machine shop ERG visited, some of the enclosures and/or LEV systems were in need of upgrade. During a site visit in 2004 (ERG Beryllium Site 9, 2004), six full-shift PBZ results ranged from 0.1 ug/m3 to 2.3 ug/m[3], with a mean of 0.68 ug/m[3] and a median of 0.25 ug/m[3]. The highest exposure (2.3 ug/m[3]) was associated with surface grinding operations that had partially enclosed LEV systems and used a flood coolant. However, visible airborne coolant contaminated with beryllium particles was generated at high speeds and observed escaping the existing control system. ERG investigators made recommendations for fully enclosing the surface grinder at the time of the visit. The facility subsequently designed and installed fully enclosed LEV systems on the surface grinder operations and reported that operator exposure was reduced from an average of 1.6 ug/m3 to 0.08 ug/m[3], based on the results of their air monitoring program (ERG Beryllium Site 9, 2004). Both of these facilities (ERG Sites 1 and 9) machine pure beryllium and/or high-beryllium alloys; however, the benefits of using ventilated enclosures are evident and would be applicable to any machining operation regardless of the beryllium content of the materials handled.
Wet Methods
In the series of industrial hygiene surveys conducted by Materion Corporation, the investigator measured full-shift PBZ exposure levels before and after interventions for machine shop workers performing semi-automated lapping while refurbishing cast beryllium alloy shapes (MC Pkg I-D, 2010). "Dry [lapping] work practices were observed during baseline sampling that resulted in a 0.51 ug/m[3] exposure to the operator." Plant managers confirmed that the work should have been done wet with flood coolant. Follow-up samples were collected after "work practice controls prohibited dry [lapping]; [14 results] ranged from 0.007 ug/m3 to 0.2 ug/m[3] with an average of 0.062 ug/m[3]" (MC Pkg I-D, 2010).  These sample results demonstrate the value of wet methods in controlling fine particles released by abrasive action of semi-automated surface shaping tasks on material surfaces. .
Work Practice Improvements
Other control methods for grinding/finishing operators include minimizing work practices that increase exposure. For example, at one facility where pure beryllium and high-beryllium alloys are machined, an exposure level of 6.6 ug/m[3] was obtained on a machinist operating a fully enclosed and ventilated double-sided lapper (ERG Beryllium Site 4, 2003). During the machining cycle, investigators noted that the worker opened the machine enclosure four or five times to check on the progress of the parts. It is likely that this work practice increased the operator's exposure to beryllium. This judgment is supported by the findings of a NIOSH study that identified peak metalworking fluid exposures to machine operators in the course of their work (NIOSH ECTB 218-12a). Using video exposure monitoring and an aerosol photometer, NIOSH investigators observed that both full and partial entry into a machining center led to higher operator exposures. One worker had his highest metalworking fluid exposure when he was cleaning inside a machining center.  Another worker experienced his highest exposures at the open door of partially enclosed machining centers, at times with his arm inside the enclosure.
Eliminating or minimizing poor work practices will help reduce exposures for workers machining beryllium-containing materials. Although the double-sided lapper example may not pertain to all foundry finishing operations (e.g., many finishing operations require the operator to manually hold the part or the finishing tool and may not be able to use full enclosures), it illustrates the impact of worker technique on exposures. As mentioned in the subsection on Furnace Operator  - Additional Controls, Enhanced Work Practices, according to the primary beryllium producer's suggested exposure reduction range, work practice improvements might reduce exposures by approximately 35 percent on average.
Other Control Methods
Some of the available methods for reducing the beryllium exposure of grinding/finishing operators are specific to the casting process (e.g., decreasing casting defects). The grinding/finishing operators in foundries typically work on the castings produced by other workers in the same facility. This gives foundries an added opportunity to reduce the exposure of their own grinding/finishing operators by producing the cleanest possible castings. To do this, they can reduce the amount of oxide on the surface of castings as well as the quantity of casting defects that require grinding and/or finishing.
Pre-cleaning Castings
Most castings can be pre-cleaned using enclosed, automated, and ventilated processes, such as vibrating abrasive media, rotary media drums, or enclosed shot blasting (Huston, 1981; South Cast Equipment, 2000; Pangborn, 2000). Pre-cleaning is typically performed after shakeout, but in some cases these pre-cleaning methods can replace the shakeout process entirely (South Cast Equipment, 2000). Pre-cleaning produces cleaner castings and thus reduces labor associated with grinding and other finishing tasks (Huston, 1981; Didion, 2011). This means that grinding/finishing operators would need to spend less time working on beryllium alloy castings and therefore reduce the overall beryllium exposure associated with these tasks.
Reducing Casting Defects
Sand inclusions, surface imperfections, and other defects incorporated into casting surfaces are chipped or ground out by grinding/finishing operators. According to a report in Modern Casting magazine, nine different process-related problems can leave sand tightly adhered to the casting surface (burn-in), and 11 process problems can result in sand embedded as projections into the casting (sand inclusions) (Spada, 2000). Causes include low or high mold moisture, or the wrong sand mixture, and equipment problems. Once identified, each cause can be eliminated by modifying and improving process quality control (Spada, 2000). Use of refractory mold and core coatings can also minimize burn-in (Coelho and Bharati, 1999). Another option is substitution of one granular medium for another that reduces the incidence of burn-in. For example, five gray and ductile iron foundries testing a ceramic alternative to silica sand for casting reported reduction of burn-in/burn-on during green sand, core, shell, and lost foam casting applications (Carbo, 2000). One of these foundries (Number 6) reported an estimated 90 percent reduction in burn-in when it switched to the alternate ceramic media for cores.
Reducing Surface Oxide
Some casting methods reduce formation of surface oxide by preventing the molten metal from contacting oxygen in air. These casting methods include die-casting and other reusable solid molds into which metal is poured. The solid metal walls of the mold stay in contact with the molten metal and exclude air. Methods that cool the metal quickly, such as direct chill casting, reportedly offer an added benefit. These rapid cooling methods reduce the time that high-temperature metal surfaces are in contact with oxygen in the air and thus reduce surface oxide formation (Corbett, 2004). Direct chill casting, involving a chilled water jacket circulating around the mold, is the method used by the copper-beryllium casting facility ERG visited (ERG Beryllium Site 7, 2003). The castings at this site were described as "clean" and generally free of loose surface oxides (Corbett, 2005). Other casting facilities use water baths on molds and water spray on hot castings for the same purpose -- to rapidly cool the casting surface and minimize the opportunity for oxides to form. A smelting facility visited by NIOSH used this technique to cool cast anodes (NIOSH HETA 82-024-1428).
Grinding/Finishing Operator -- Conclusion
Based on the exposure profile presented in Tables IV-29 and IV-30, an exposure level of 0.2 ug/m[3] or less has already been achieved for slightly greater than 73 percent of grinding/finishing operators. Additional controls will be required to reduce the beryllium exposure of the remaining 26.8 percent of grinding/finishing operators to 0.2 ug/m[3] or less. Based on information contained in this section, OSHA preliminarily concludes that by using either tabletop booth enclosures (250 fpm across the booth face) that are associated with downdraft-backdraft workbenches, or wet dust control methods, and by simultaneously implementing Materion Corporation's Worker Protection Model, the exposure for all workers in this job category can be reduced to 0.2 ug/m[3] or less. As previously discussed, Materion Corporation's Worker Protection Model involves specific steps to maintain cleanliness of clothing, skin and work areas; avoid spreading beryllium particles; and prepare workers for safe work with standard operating procedures and appropriate training. After downdraft-backdraft booths and Worker Protection Model controls were implemented in a facility where workers resurfaced foundry-cast beryllium alloy dies using hand-held pneumatic and electric grinding tools, results from 23 full-shift personal samples had a mean of 0.03 ug/m[3] and all results were 0.06 ug/m[3] or less. This maximum value represents a 94 percent reduction compared to the maximum value of 0.9 ug/m[3] associated with the less effective ventilation control originally in use (MC Pkg I-D, 2010). The same series of industrial hygiene studies showed that during wet lapping 14 exposure levels ranged from 0.007 ug/m3 to 0.2 ug/m[3] with a mean of 0.062 ug/m[3] (MC Pkg I-D, 2010). In contrast, a sample result of 0.51 ug/m[3] had been obtained when a worker performed the same lapping task using dry methods.
Based on this information, OSHA preliminarily concludes that an exposure level of 0.2 ug/m[3] or less can be achieved for all grinding/finishing operators. To the extent that grinding equipment such as ventilated bench grinders and lapping machines can be enclosed in booths that draw 250 fpm across the opening (and that are designed to eliminate dead space inside the booth), OSHA preliminarily concludes that most grinding and finishing operator exposure levels can be reduced to an alternative PEL of 0.1 ug/m[3].
Maintenance Operators
Maintenance Operators -- Baseline Controls
Maintenance operators are exposed to beryllium when they disturb beryllium contamination that may present equipment and work surfaces. Based on information from the ERG, NIOSH, and CCMA reports, OSHA believes that maintenance operators most typically work with general dilution ventilation only, unless work is performed on equipment that is fitted with exhaust ventilation (CCMA, 2000; NIOSH HHE 78-17-567; ERG Beryllium Site 7, 2003). When working on ventilated equipment, such as furnaces, the process exhaust ventilation system might offer some degree of exposure control for the maintenance operator, but is unlikely to be designed to provide optimal control of maintenance activities. As an example, furnace ventilation hoods are designed to capture fumes released from the top of the furnace, rather than from the furnace interior where a maintenance operator might chip and patch the refractory lining. Some foundries may have LEV systems available for maintenance activities. Other baseline conditions include dry sweeping and the use of compressed air; however, central or portable HEPA vacuums are available in some nonferrous foundries for cleaning equipment and removing dirt and dust from work surfaces.
Maintenance Operators -- Additional Controls
The exposure profile for maintenance operators shows a range of exposures from 0.05l ug/m[3] to 22.71 ug/m[3], with a median exposure level of 0.21ug/m[3]. Based on the exposure profile presented in Tables IV-29 and IV-30, 50 percent of maintenance operators have exposures that exceed 0.2 ug/m[3] and will require additional controls to reduce exposures to 0.2 ug/m[3] or less. Available control options include process equipment changes, wet methods, HEPA filter vacuums, LEV (including the use of ventilated tools), and work practice improvements.
Process-related engineering controls can reduce exposures. This control option is particularly beneficial if exposure levels routinely exceed the current PEL of 2.0 ug/m[3]. For example, as noted in the subsection on Exposure Profiles for Affected Job Categories in this Aluminum and Copper Foundries section, to reduce maintenance operator exposures when emptying the facility's dust collectors, a beryllium production facility installed automatic valve cut-offs activated by drum level sensors to control the amount of waste released into drums (NIOSH HHE 78-17-567). Using exposure data collected by the facility, OSHA estimated that PBZ exposures were reduced about 93 percent over one year, from 53 ug/m[3] (one result) in the first quarter of 1977 to 3.62 ug/m[3] (average of three results) in the first quarter of 1978. Applying this reduction to the highest exposures (16.51 ug/m[3] and 22.71 ug/m[3]) brings these extremely high levels to values ranging from 1.2 ug/m3 to 1.6 ug/m[3].
Materion Corporation reports that the repair or maintenance of equipment, including process ventilation equipment, can generate airborne beryllium particles (Materion SF 102, 2011; Materion SF 201, 2011). Protecting workers may require specific work practices or procedures involving the combined use of decontamination, wet and vacuum cleaning methods, ventilation, PPE including respiratory protection, and possibly restricted work zones. To implement these controls, foundries will need to develop detailed procedures for safely maintaining process equipment and ventilation systems. These procedures should thoroughly describe the use of wet methods or vacuuming, ventilation, and appropriate PPE to prevent maintenance operator exposure to airborne beryllium. In addition, all maintenance operators need to be trained in the proper procedures before performing any maintenance or service activities. Appropriate combinations of these methods must be used (by the maintenance operator or another worker assigned this part of maintenance operator duties) to pre-clean process equipment to remove residual beryllium before the maintenance operator begins maintenance or repair work.
HEPA Filter Vacuums
Process equipment and associated support systems (e.g., dust collectors) should be cleaned regularly to prevent the accumulation of beryllium-containing materials and before any service or maintenance. HEPA filter vacuuming and wet cleaning are effective methods for cleaning contaminated work surfaces; only these methods should be used to clean beryllium work areas (Materion SF 201, 2011; OSHA-H005C-2006-0870-0155). Dry sweeping and the use of compressed air for cleaning should be prohibited. As noted during the discussion of additional controls for molders, in some cases a worker's primary exposure to beryllium has been due to the use of compressed air.
During the emptying or maintenance of HEPA vacuums, beryllium-containing particles may be released into the workplace. To minimize the potential for exposure, employers will need to develop and implement proper procedures for emptying and maintaining HEPA vacuums. These procedures include all of the following provisions (Materion Interactive Guide, 2012):
Conduct all service and maintenance on HEPA vacuums in accordance with the manufacturer's instructions.
Wear appropriate PPE (such as disposable coveralls, gloves, and respirators) during the entire process, including cleanup.
Use a designated, contained area for servicing HEPA vacuums.
Place plastic sheeting or another suitable material on the floor to contain any material that may be released and to facilitate cleanup afterwards.
Use ventilation or other engineering controls, where feasible, to control the release of airborne particles.
Place the material removed from the vacuum (dust, debris, prefilters, etc.) in a heavy-duty plastic bag and seal the bag with tape or by some other means. Then place this bag inside a second bag and seal, label, and dispose of appropriately.
Use another HEPA vacuum or wet cleaning methods to clean the area (after completing the maintenance), including the vacuum that was serviced.
Local Exhaust Ventilation
For most maintenance operators, the primary control might include portable LEV systems or stationary systems that can be adapted to benefit the maintenance operator. As was previously noted, maintenance operators' work positions may limit the benefit of process ventilation systems on the equipment they service. For example, tundish repair can occur on the pouring line floor near exhaust ventilation intended for the hot molds. A slotted hood or duct trunk at the pouring station might provide some exposure control when the tundish is between the worker and the hood; however the control is not typically constant. Eventually as work progresses around the tundish, the worker's back will be to the ventilation hood and contaminated air from the tundish cleaning might be pulled past the worker's breathing zone.
This challenge can be resolved by an enclosure or booth placed around the work (or work placed inside an enclosure that the operator reaches into). Materion Corporation has installed a large ventilated booth in which movable refractory equipment is placed for refractory replacement or repair work (Materion Meeting, 2012). For stationary equipment with refractory lining, a company that provides refractory overhaul services developed a method for installing temporary LEV. This method is used for complete lining removal, but is also applicable to smaller (patching) jobs in gas-fired furnaces. It involves company-built exhaust fans fitted with air filters (three filters of increasing efficiency in series) (Refractory Services Provider A, 2003). The fans create an air flow pattern in the furnace that pulls fresh air from outside the furnace past the worker's face and removes dusty air from near the chipping point. Workers stretch plastic sheeting as necessary to ensure that the fresh air enters the furnace only from the most advantageous point (for the purpose of providing clean air to the worker), while they set one or more fan/filter boxes into the opposite and lower end of the furnace to exhaust contaminated air. Existing openings, such as access hatches and gas vents, are used as needed to maintain favorable circulation (Refractory Services Provider A, 2003). The sheeting and boxes might need to be moved to other sections of the furnace as the work progresses. Although the fan/filter boxes are specially built for this purpose, they are made of materials readily available at hardware stores and cost relatively little to construct (Refractory Services Provider A, 2003).
Providing exhaust ventilation throughout a process, from start to finish, will help maximize control of metal dust and fumes (CCMA, 2000). The ventilation system will be equally effective for particles with similar aerodynamic properties, regardless of whether the airborne dust or fumes are cadmium, lead, or beryllium (see Section 2 -- Methodology for additional information on the behavior of particles in air). Maintenance operators who repair refractory linings benefit from enclosed, exhausted waste receptacles to hold debris generated during the repair process. Beryllium-contaminated waste (such as spent refractory materials) generated during maintenance activities should be transferred under LEV from the furnace or tundish to the receptacle.
Downdraft/backdraft enclosures at workbenches have also proven effective for work with hand tools in facilities working on beryllium alloy castings. As described in detail in the section discussing additional controls for the molder job category (elsewhere in this chapter on copper and beryllium foundries), three grinder operators initially experienced exposure levels ranging from 0.012 ug/m[3] to 0.900 ug/m[3] while using downdraft or exhaust trunk ventilation. After additional controls were implemented, results from 28 samples indicated that exposures were reduced to a range of 0.0084 ug/m[3] to 0.0577 ug/m[3], representing a 94 percent reduction in the maximum exposure level compared to exposure levels measured while workers used the less effective ventilation systems originally in place (MC Pkg I-D, 2010). The additional controls used to achieve this reduction included a benchtop booth (enclosing the top, back, and sides of the work area, with an open front through which the worker reached) installed over a downdraft-backdraft table.
Ventilated Hand Tools
The benefits of tool-mounted exhaust systems for controlling beryllium have been demonstrated in the control of hazardous dusts (such as crystalline silica) in other industries, including construction and ready-mix concrete. For example, the chipping of refractory materials is similar to chipping concrete, another silica-containing material. To evaluate chipping equipment, NIOSH tested two tool-mounted LEV shrouds for hand-held pneumatic chipping equipment (impact drills): one custom built, the other a commercially available model. Comparing multiple short-term samples, NIOSH found that the shrouds reduced PBZ respirable dust by 48 percent to 60 percent (NIOSH EPHB 282-11a).
Independently, Shepherd et al. (2009) studied hand-held drills and found that, compared with uncontrolled hole drilling, using dust collection cowls connected to portable vacuums reduced respirable dust exposure by 83 to 88 percent and inhalable dust 80 to 94 percent. This study shows that a well-designed dust capture device can be similarly effective for respirable and total (inhalable) dust. Although dust extraction devices such as these are sometimes only evaluated for ability to capture one specific type of dust (e.g., respirable dust), many will perform similarly well for capturing all airborne dust, including total dust containing beryllium. An increasing number of ventilated (i.e., fitted with vacuum suction for dust extraction) power hand tools and after-market shrouds for power hand tools are available from commercial sources (Bosch Tools, 2013; Dustless Tools-Shrouds, 2012; Milwaukee Tools, 2013).
Work Practices
Maintenance operators can reduce their beryllium exposures by cleaning production equipment and associated support systems (such as dust collectors) prior to service or maintenance to remove as much beryllium contamination as possible. HEPA filter vacuums should be used to remove gross surface contamination followed by wet wiping. To control airborne dust generated by their activities, maintenance operators should also use portable ventilation units with HEPA filtration. Because the operator controls and adjusts these tools, operator work practices could be a factor in the higher exposures reported for some maintenance operators. Workers not only need to use these controls consistently and diligently, they also need to use them correctly, such as properly positioning portable LEV units for maximum effect and using appropriate procedures for emptying and maintaining HEPA vacuums as described above.
Foundries can also reduce maintenance operators' beryllium exposure by using administrative controls such as scheduling routine maintenance to avoid times when an incompletely controlled process is being conducted in the area. Work practices such as limiting the number or location of operators working in a furnace at one time could reduce maintenance operator exposures during chipping activities. During an evaluation of respirable crystalline silica, OSHA obtained a notably higher result for a worker reportedly using a jackhammer in the "lower part of a [furnace]" than was reported for the second operator who also used a jackhammer during the same evaluation (OSHA SEP Inspection Report 116201997). Sweeney and Gilgrist (1998) also reported a higher respirable silica exposure level for an operator working in a lower position within a 1,100-pound holding furnace for molten aluminum:
Of the two workers involved in performing this project, the higher exposure occurred to employee 1, who did less of the jackhammering but more of the grabbing and tossing of the pieces and chunks of old refractory material. This apparently was because his head was down closer to the jackhammer's point of operation and dust generated than the head of operator 2, who was standing up and operated the jackhammer. However, both employees were overexposed to the respirable dust containing crystalline silica (Sweeney and Gilgrist (1998)).
Reducing Dross and Oxide Production
Any success in reducing dross formation at the surface of the molten metal (as discussed for the furnace operator job category) is also likely to reduce deposition of dross onto furnace walls. However, because of the limited experience with these controls and problematic results in applications, the benefit of this control has not been quantified. Even if a method such as inert gas layering were to be successfully implemented at the furnace, some oxide is likely to occur at the ladle and tundish, although the quantity might be limited because metal poured from the furnace would be cleaner.
Maintenance Operators -- Conclusion
As indicated in the exposure profile (Tables IV-29 and IV-30), a median exposure level of 0.21 ug/m[3] (and a range of 0.05 ug/m[3] to 22.71 ug/m[3]) describes the best available exposure data for maintenance workers. Based on these data, OSHA preliminarily concludes that foundries have achieved exposure levels of 0.2 or less for half of all maintenance operators, primarily by providing work areas with little active beryllium emission and low dust contamination. However, it is also the case that 50 percent of the workers in this job category have exposures greater than 0.2 ug/m[3] and require additional controls to further reduce exposures to 0.2 ug/m[3] or less. These controls primarily include a combination of LEV, HEPA filter vacuums, wet methods (e.g., for cleaning and dust suppression during manual demolition) and enhanced work practices (e.g., consistently and diligently decontaminating work surfaces and equipment prior to service or maintenance, and correctly and consistently using LEV). In some cases, process modifications might be necessary. Beryllium exposure reductions specific to these additional controls, either individually or in combination, are not available for maintenance operators in nonferrous foundries. However, Materion Corporation has stated that HEPA filter vacuuming and wet cleaning are effective methods for cleaning contaminated work surfaces and only these methods should be used in beryllium work areas (Materion Info Meeting, 2012; Materion SF 201, 2011; OSHA-H005C-2006-0870-0155). Materion Corporation strives for exposure levels below 0.2 ug/m[3] and typically achieves this level for most workers most of the time, including maintenance operators.
Based on the information described in this section, OSHA preliminarily concludes that the proposed PEL of 0.2 ug/m[3] can be achieved for most maintenance workers most of the time. Based on available information, OSHA believes that achieving an alternative PEL of 0.1 ug/m[3] for this job category most of the time with the use of engineering and work practice controls is challenging. Therefore, the Agency requests additional information (including exposure data and effectiveness of controls) to make a determination about the feasibility of an alternative PEL of 0.1 ug/m[3].
In some circumstances, however, engineering controls will not be feasible due to the nature or infrequency of the job (e.g., during upset conditions). In other cases, maintenance operators may require supplemental protection while performing pre-cleaning to reduce exposure levels during the maintenance or repair task. In both of these cases, supplemental use of respiratory protection may be necessary. The level of protection will vary with the circumstances, but in all cases the respirator must have an assigned protection factor (APF) that offers a MUC of at least the anticipated exposure level. For example, a tight-fitting powered air-purifying respirator will provide an APF of 1,000. For the proposed PEL of 0.2 ug/m[3], this will permit the maintenance operators to work in environments containing airborne beryllium concentrations up to 200 ug/m[3]. With an APF of 50, a tight-fitting air-purifying respirator (non-powered) will be suitable for use up to a beryllium concentration of 10 ug/m[3]. Although the most elevated exposure levels in the exposure profile for this job category exceed 10 ug/m[3], process equipment modifications are likely to reduce even the highest exposure level to the point where an APF of 50 would be suitable; for example, process equipment modifications reduced extremely elevated maintenance operator exposures by 95 percent (from 53 ug/m3 to 3.62 ug/m[3]) (NIOSH HHE 78-17-567). However, in a few foundries, as indicated by maintenance operators that currently experience results exceeding 20 ug/m[3], a respirator with an APF of 1,000 (e.g., full-facepiece powered air purifying respirator) might be necessary until process changes can be made.
Summary of the Technological Feasibility for Aluminum and Copper Foundries
OSHA identified eight job groups in aluminum and copper foundries with routine beryllium exposure: molding, material handling, furnace operation, pouring, shakeout operation, abrasive blasting, grinding/finishing, and maintenance.  The Agency developed exposure profiles based on an industrial hygiene evaluation conducted by NIOSH in 2007 and a Health Hazard Evaluation (HHE) conducted in 1975, an ERG site visit in 2003, a site visit report from 1999 by the California Cast Metals Association (CCMA); and data air sampling surveys conducted in 1999 and from 2007 to 2009, obtained from Materion in 2004 and 2010, respectively.
The exposure profile indicates that in foundries processing beryllium alloys, six of the eight job groups identified have median exposures that exceed the proposed PEL of 0.2 μg/m[3] with baseline working conditions.  One exception is grinding/finishing operations, where the median value is 0.12 μg/m[3] and 73% of exposure samples are below 0.2 μg/m[3].  The profile for abrasive blasting, which was conducted using an enclosed cabinet, also showed low beryllium exposures (i.e., 5 samples below 0.2 μg/m[3]).  Exposures for other job groups ranged from just below to well above the proposed PEL, including molder (all samples above 0.2 μg/m[3]), material handler (1 sample, above 0.2 μg/m[3]), furnace operator (81.8% of samples above 0.2 μg/m[3]), pouring operator (60% of samples above 0.2 μg/m[3]), shakeout operator (1 sample, above 0.2 μg/m[3]), and maintenance worker (50% of samples above 0.2 μg/m[3]).
In some of the foundries where the air samples included in the exposure profile were collected, there are indications that the ventilation systems were not properly used or maintained, and dry sweeping/brushing and compressed air systems may have contributed to high dust levels. OSHA preliminarily concludes that beryllium exposures in foundries can be substantially reduced by improving and properly using and maintaining the ventilation systems; switching from dry brushing, sweeping and compressed air to wet methods and HEPA-filtered vacuums for cleaning molds and work areas; enclosing processes; automation of high-exposure tasks; and modification of processes (e.g., switching from sand-based to alternative casting methods), and improved work practices.  Therefore, OSHA preliminarily concludes that additional engineering controls and modified work practices can be implemented to achieve the proposed PEL most of the time for molding, material handling, maintenance, abrasive blasting, grinding/finishing, and pouring operations at foundries that produce aluminum and copper beryllium alloys.
The Agency is less confident that exposure can be reliably reduced to the proposed PEL for furnace and shakeout operators.  Beryllium concentrations in the proximity of the furnaces are typically higher than in other areas due to the fumes generated and the difficulty of controlling emissions during furnace operations.  The exposure profile for furnace operations shows a median beryllium exposure level of 1.14 μg/m[3].  OSHA preliminarily concludes that furnace operators' exposures can be reduced using local exhaust ventilation and other controls to reduce overall beryllium levels in foundries, but it is not clear that they can be reduced to the proposed PEL with currently available technology.  In foundries that use sand molds, the shakeout operation typically involves removing the freshly cast parts from the sand mold using a vibrating grate that shakes the sand from castings.  The shakeout equipment generates substantial amounts of airborne dust that can be difficult to contain, and therefore shakeout operators are typically exposed to high dust levels.  When casting beryllium alloys, the dust may contain beryllium and beryllium oxide residues dislodged from the casting during the shakeout process.  The exposure profile for the shakeout operations contains only one result, of 1.3 μg/m[3].  This suggests that a substantial reduction would be necessary to achieve compliance with a proposed PEL of 0.2 μg/m[3].  OSHA requests additional information on employee exposure levels and the effectiveness of dust controls for shakeout operations for copper and aluminum alloy foundries.
Additionally, OSHA preliminarily concludes that an alternative PEL of  0.1 μg/m[3] would be feasible for molders, material handlers, abrasive blasting operators, and grinding and finishing operators. For the other four job categories, OSHA believes that achieving levels at or below an alternative PEL of 0.1 μg/m[3] would be challenging with the engineering and work practice controls identified in this analysis. OSHA is requesting additional information that the Agency can consider to make its final feasibility findings.
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ERG Silica_GenInd1v.2, 2008. Technological Feasibility Study of Regulatory Alternatives for a Proposed Crystalline Silica Standard for General Industry, Volume 1. August 2008 draft (version 2). Draft report submitted to OSHA by Eastern Research Group, Inc. Lexington, Massachusetts.
Estill, C.F., 2004. Personal communication between a representative of Eastern Research Group, Inc., Lexington, Massachusetts, and Cheryl F. Estill, Industrial Hygiene Supervisor, National Institute for Occupational Safety and Health, Division of Surveillance, Hazard Evaluations and Field Studies. April 6.
Fedvendor.com, 2004-2005. Company profile for Peregrine Falcon Corporation, Pleasanton, California. Fedvendor.com website http://www.fedvendor.com/contractor/CRR00000000000144162/profile.htm. Accessed June 14, 2013.
Hall, R.M., W.A. Heitbrink, and L.D. Reed, 2002. Evaluation of a Tractor Cab Using Real-Time Aerosol Counting Instrumentation. Applied Occupational and Environmental Hygiene 17(1): 47 - 54. January.
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Hartle, R.W., 2004. Personal communications between Richard W. Hartle, Assistant Chief, Hazard Evaluation and Technical Assistance Branch, National Institute for Occupational Safety and Health, and a representative of Eastern Research Group, Inc. Lexington, Massachusetts. April 1 - 12.
Heinonen K., I. Kulmala, and A. Säämänen, 1996. Local Ventilation for Powder Handling -- Combination of Local Supply and Exhaust Air. American Industrial Hygiene Association Journal 57:356 - 364. April.
Houska, C., 1988. Beryllium in Aluminum and Magnesium Alloys. Metals and Materials Magazine. February. Available online at: http://materion.com/~/media/Files/PDFs/Alloy/Technical%20Papers/AP0012%20-%20Beryllium%20in%20Aluminum%20and%20Magnesium%20Alloys.pdf. Accessed March 13, 2012.
Huang, R., G. Liu, S. Lin, Y. Chen, S. Wang, C. Peng, W. Yeh, C. Chen, and C. Chang, 2004. Development and Characterization of a Wake-Controlled Exterior Hood. Journal of Occupational and Environmental Hygiene 1:769 - 778. December.
Huston, R.N., 1981. Abstract Number 820130. Cast Cleaning Methods -- Vibratory Finishing. Cleaning Room Technology -- An Update for the 80s. Proceedings of AFS/CMI Conference, Rosemont, Illinois. Pages 89-102. October 14 - 15. Available online at: http://www.castmetals.com. Accessed December 21, 2000.
Industrial Hygiene West, 2000. Evaluation of Occupational Hazards Using High Pressure Water Jetting. Prepared by Industrial Hygiene West for the U.S. Army National Guard. September.
Irwin. 2003. Overexposure to Crystalline Silica in a Foundry Operation, OSHA Compliance Issues column, R.E. Fairfax, Column Editor. Applied Occupational and Environmental Hygiene 18(1):18-21. January.
Johnson, B., 2002. Telephone conversation between Buck Johnson, Ceramet and John L. Bennett, consultant to Eastern Research Group, Inc. February 18.
Kent, M.S., T.G. Robins, and A.K. Madl, 2001. Is Total Mass or Mass of Alveolar-Deposited Airborne Particles of Beryllium a Better Predictor of the Prevalence of Disease? A Preliminary Study of a Beryllium Processing Facility. Applied Occupational and Environmental Hygiene 16(5): 539 - 558.
Kent, M.S., 2005. Personal communications between Eastern Research Group, Inc. and Michael S. Kent, CIH, CSP, Director Environmental, Health and Safety, Brush Wellman Inc. Elmore, Ohio. January and February.
Kinergy Corporation, 2000. Telephone conversation between a representative of Kinergy Corporation, Louisville, KY, and Eastern Research Group, Inc. November 30.
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Kramer. 2012. Abrasive Blasting Media. Kramer Industries, Inc. Piscataway, New Jersey. Available online at: http://www.kramerindustriesonline.com/blasting-media.htm. Accessed June 6.
Kriebel, D., N.L. Sprince, E.A. Eisen, and I.A. Greaves, 1988. Pulmonary Function in Beryllium Workers: Assessment of Exposure. British Journal of Industrial Medicine 45: 83 - 92.
KTA-Tator-Phase-1, 1998. Evaluation of Substitute Materials for Silica Sand in Abrasive Blasting. KTA-Tator, Inc. Prepared for U.S. Department of Health and Human Services. Public Health Service. Centers for Disease Control and Prevention. National Institute for Occupational Safety and Health. Contract No. 200-95-2946. September.
Martyny, J.W., M.D. Hoover, M.M. Mroz, K. Ellis, L.A. Maier, K.L. Sheff, and L.S. Newman, 2000. Aerosols Generated During Beryllium Machining. Journal of Occupational and Environmental Medicine 42(1): 8 - 18.
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Materion Information Meeting. 2012. Personal communication during meeting between Materion Corporation and OSHA. Elmore, Ohio. May 8-9.
Materion PSCS 105, 2011. Benching (Grinding and Polishing) Copper-Beryllium Alloys. Process Specific Control Summary (PSCS) 105. Materion Brush Inc. Mayfield Heights, Ohio. July 18.
Materion SF 102, 2011. Safety Practices for Sanding, Grinding, Buffing, Lapping and Polishing Copper-Beryllium Alloys. Safety Facts (SF) 102, Version 2. Materion Brush Inc. Mayfield Heights, Ohio. March.
Materion SF 201, 2011. Safety Practices for Working with Beryllium Products, SF 201 -- Version 2, March 2011. Materion Brush Inc. Mayfield Heights, Ohio. Available online at: http://materion.com/~/media/Files/PDFs/Corporate/BeSafetyFacts/SF201-SafetyPracticesforWorkingwithBeryllium.pdf.
MC Pkg I-D, 2010. Industrial Hygiene Survey of June 2007 through April 2009 -- Final Report: Plastic blow molding fabrication operations using copper beryllium (CuBe) Alloy 25 inserts; report dated 14 January, 2010. Part D of Information Package I received May 29, 2012, from Materion Corporation by OSHA/DSG/OTF.
MDA, 2011. Technology Profile #403. Castable Beryllium-Aluminum Alloys. (Starmet Corporation, Concord, Massachusetts.) Missile Defense Agency, Technology Applications Program. Available online at: http://www.mdatechnology.net/techprofile.aspx?id=403. Accessed November 09, 2011.
Mento, C., G. Williams, B. Prince, and R. Ryan, no date. Surrogate Powder and ASHRAE-110 Testing of a Multi-purpose Enclosure for Weighing/Sieving/Fluid Bed Dryer Applications. Flow Sciences, Inc. Leland, North Carolina.
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NFFS, 2002. Telephone conversation between a representative of the Non-Ferrous Founders' Society and John L. Bennett, consultant to Eastern Research Group, Inc. February 12.
NIOSH 79-114. An Evaluation of Occupational Health Hazard Control Technology for the Foundry Industry. U.S. Department of Health, Education, and Welfare, Public Health Service, Center for Disease Control, National Institute for Occupational Safety and Health, Division of Physical Sciences and Engineering. Cincinnati, Ohio. DHEW/NIOSH Publication No. 79-114. (NTIS publication number PB297-560.) October 1978. Recorded as a supporting document at www.regulations.gov, under Document ID number OSHA-2010-0034-1382.
NIOSH 85-116. Recommendations for Control of Occupational Safety and Health Hazards: Foundries. National Institute for Occupational Safety and Health. Cincinnati, Ohio. DHHS (NIOSH) Publication No. 85-116. September 1985. Available online at: http://www.cdc.gov/niosh/85-116.html. Accessed November 10, 2011.
NIOSH-CAL/OSHA-ltr, 2007. Letter from NIOSH, Engineering and physical Hazards Branch, addressed to Cal/OSHA Consultation Services. March 23.
NIOSH ECTB 202-15b. In-Depth Survey Report: Control Technology for Metal Reclamation Industries at East Penn Manufacturing Company, Inc. Lyon Station, Pennsylvania. Report No. ECTB 202-15b. U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Division of Physical Sciences and Engineering. Cincinnati, Ohio. June 3, 1996.
NIOSH ECTB 218-12a. In-Depth Survey Report: Concentration of Metalworking Mists Before and After Installation of a Commercial Air Cleaner at Sauer-Sundstrand Company, Ames, Iowa. Report No. ECTB 218-12a. U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Division of Physical Sciences and Engineering, Engineering Control Technology Branch. Cincinnati, Ohio. July 25, 1997.
NIOSH ECTB 233-106c. Control Technology and Exposure Assessment for Occupational Exposure to Crystalline Silica: Case 06 -- Monument Manufacturing. Report No. ECTB 233-106c. U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Division of Physical Sciences and Engineering. Cincinnati, Ohio. August 5, 1999.
NIOSH ECTB 233-107c. Control Technology and Exposure Assessment for Occupational Exposure to Crystalline Silica: Case 07 -- A Gray Iron Foundry Operation. Report No. ECTB 233-107c. U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Division of Physical Sciences and Engineering. Cincinnati, Ohio. April 2000.
NIOSH EPHB 233-131c. Control Technology and Exposure Assessment for Occupational Exposure to Crystalline Silica: Case 31 -- A Granite Shed. Report No. EPHB 233-131c. U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Division of Physical Sciences and Engineering. Cincinnati, Ohio. August 2000.
 NIOSH EPHB 233-133c. Control Technology and Exposure Assessment for Occupational Exposure to Crystalline Silica: Case 33 -- A Gray Iron Foundry with Computational Fluid Dynamics Used to Analyze an Existing Control and Model Proposed Modifications Report No. EPHB 233-133c. U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Division of Physical Sciences and Engineering. Cincinnati, Ohio. January 2002.
NIOSH EPHB 282-11a. In-Depth Survey Report: Control of Respirable Dust and Crystalline Silica from Breaking Concrete with a Jackhammer at Bishop Sanzari Companies, North Bergen, New Jersey. Report No. EPHB 282-11a. U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Division of Applied Research and Technology, Engineering and Physical Hazards Branch. Cincinnati, Ohio. February 2003.
NIOSH EPHB 326-11a. Control Technology and Exposure Assessment for Occupational Exposure to Beryllium: Beryllium Facility #1 -- Copper/Beryllium Foundry. Report No. EPHB 326-11a. U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Division of Applied Research and Technology. Cincinnati, Ohio. July 2008.
NIOSH EPHB 326-16a. Control Technology and Exposure Assessment for Occupational Exposure to Beryllium: Beryllium Facility #3 -- Aluminum/Beryllium Foundry, and Copper/Beryllium Foundry and Machine Shop. Report No. EPHB 326-16a. U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Division of Applied Research and Technology. Cincinnati, Ohio. November 2008.
NIOSH HHE 75-87-280. Health Hazard Evaluation Determination Report No. 75-87-280, Kawecki Berylco Industries, Inc., Reading, Pennsylvania (NTIS document number PB89-161251). National Institute for Occupational Safety and Health. Cincinnati, Ohio. April 1976.
NIOSH HHE 78-17-567. Health Hazard Evaluation Determination Report No. 78-17-567, Kawecki Berylco Industries, Inc., Reading, Pennsylvania (NTIS document number PB81-143703. U.S. Department of Health, Education, and Welfare, Center for Disease Control, National Institute for Occupational Safety and Health, Health Hazard and Technical Assistance Branch. Cincinnati, Ohio. March 1979.
NIOSH HETA 82-024-1428. Health Hazard Evaluation Report No. HETA 82-024-1428, Chemetco, Incorporated, Alton, Illinois. National Institute for Occupational Safety and Health. Cincinnati, Ohio. March 1984.
NIOSH HETA 83-015-1809. Health Hazard Evaluation Report No. HETA 83-015-1809. Wellman Dynamics Corporation, Creston, Iowa. National Institute for Occupational Safety and Health. Cincinnati, Ohio. July 1987.
NIOSH HETA 85-482-1730 / 86-116-1730. Health Hazard Evaluation Report No. HETA 85-482-1730 / 86-116-1730. Winters Industry Foundry, Canton, Ohio. National Institute for Occupational Safety and Health. Cincinnati, Ohio. September 1986.
NIOSH HETA 86-038-1807. Health Hazard Evaluation Report No. HETA 86-038-1807. Morris Bean and Company, Yellow Springs, Ohio. National Institute for Occupational Safety and Health. Cincinnati, Ohio. July 1987.
NIOSH HETA 86-284-1914. Health Hazard Evaluation Report No. HETA 86-284-1914. H.B. Smith Company, Inc., Westfield, Massachusetts. National Institute for Occupational Safety and Health. Cincinnati, Ohio. July 1988.
NIOSH HETA 88-244-1951. Health Hazard Evaluation Report No. HETA 88-244-1961. Orrville Bronze and Aluminum Company, Orrville, Ohio. National Institute for Occupational Safety and Health. Cincinnati, Ohio. March 1989.
NIOSH HETA 90-0249-2381. Health Hazard Evaluation Report No. HETA 90-0249-2381. Blaw Knox Rolls, Inc., Wheeling, West Virginia. National Institute for Occupational Safety and Health. Cincinnati, Ohio. January. 1994.
NIOSH HETA 91-0092-2190. Health Hazard Evaluation Report No. HETA 91-0092-2190. William Powell Company, Cincinnati, Ohio. National Institute for Occupational Safety and Health. Cincinnati, Ohio. March 1992.
NIOSH HETA 91-0093-2126. Health Hazard Evaluation Report No. HETA 91-0093-2126. Seville Centrifugal Bronze, Inc., Seville, Ohio. National Institute for Occupational Safety and Health. Cincinnati, Ohio. July 1991.
NIOSH HETA 92-044-2265. Health Hazard Evaluation Report. General Castings Company, Liberty Road Facility, Delaware, Ohio. Report No. HETA 92-044-2265. National Institute for Occupational Safety and Health. Cincinnati, Ohio. October 1992.
NIOSH HETA 92-090-2296. Health Hazard Evaluation Report. General Castings Company, Toledo Street Facility, Delaware, Ohio. Report No. HETA 92-090-2296. National Institute for Occupational Safety and Health. Cincinnati, Ohio. March 1993.
NIOSH HETA 92-092-2333. Health Hazard Evaluation Report. General Castings Company, Power Street Facility, Cincinnati, Ohio. Report No. HETA 92-092-2333. National Institute for Occupational Safety and Health. Cincinnati, Ohio. July 1993.
NIOSH HETA 92-157-2304. Health Hazard Evaluation Report No. HETA 92-157-2304. General Castings Company, Domestic Division, Shippensburg, Pennsylvania. National Institute for Occupational Safety and Health. Cincinnati, Ohio. April 1993.
NIOSH IWS-37-13. Results of Air Sampling of Kawecki Berylco Plant, at Kawecki Berylco Industries Hazelton, Pennsylvania. NIOSH Report No. IWS-37-13 (NTIS document number PB83-133397). U.S. National Institute for Occupational Safety and Health, Division of Surveillance, Hazard Evaluations, and Field Studies, Hazard Evaluation and Technical Assistance Branch. Cincinnati, Ohio. November 21, 1971.
O'Brien, D., 2000. Personal communication between Dennis O'Brien, National Institute for Occupational Safety and Health and Eastern Research Group, Inc. October 27.
OSHA, 2009.  Integrated Management Information System (IMIS).  Beryllium exposure data, updated April 21, 2009, covering the period 1978 through September 2008.  Data provided to Eastern Research Group, Inc. by the U.S. Department of Labor, Occupational Safety and Health Administration, Washington, DC.  [Unpublished, electronic files]
OSHA-H005C-2006-0870-0155  U.S. Department of Labor, Occupational Safety and Health Administration. OSHA Beryllium Docket No. OSHA-H005C-2006-0870. Document ID No. OSHA-H005C-2006-0870-0155. Document title: Public comments received from National Jewish Medical and Research Center in response to Federal Register of November 26, 2002. Dated February 20, 2003. OSHA-H054A-2006-0064-0965. U.S. Department of Labor, Occupational Safety and Health Administration. OSHA Hexavalent Chromium Docket No. OSHA-H054A-2006-0064. Docket ID No. OSHA-H054A-2006-0064-0965. Document Title: Site Visit Report. Company F (Iron and Steel Foundry). January 30, 1997.
OSHA HIB, 1999. Preventing Adverse Health Effects from Exposure to Beryllium on the Job. Hazard Information Bulletin. U.S. Department of Labor, Occupational Safety and Health Administration, Directorate of Science, Technology and Medicine, Office of Science and Technology Assessment. September 2. Available online at: http://www.osha.gov/dts/hib/hib_data/hib19990902.html.
OSHA SEP Inspection Report 100494079. OSHA Special Emphasis Program (SEP) Inspection Report 100494079. Recorded as a supporting document at www.regulations.gov, under Document ID number OSHA-2010-0034-0132
OSHA SEP Inspection Report 116201997. OSHA Special Emphasis Program (SEP) Inspection Report 116201997. Recorded as a supporting document at www.regulations.gov, under Document ID number OSHA-2010-0034-0080.
OSHA SEP Inspection Report 122122534. OSHA Special Emphasis Program (SEP) Inspection Report 122122534.
OSHA SEP Inspection Report 300530029. OSHA Special Emphasis Program (SEP) Inspection Report 300530029. Recorded as a supporting document at www.regulations.gov, under Document ID number OSHA-2010-0034-0182.
OSHA SEP Inspection Report 303207518. OSHA Special Emphasis Program (SEP) Inspection Report 303207518. Recorded as a supporting document at www.regulations.gov, under Document ID number OSHA-2010-0034-0511.
Pangborn, 2000. Surface Preparation Equipment and Product Information on Rotoblast Barrels. Pangborn Corporation. Hagerstown, Maryland. Available online at: http://www.pangborn.com/products1b.html. Accessed December 27.
Pangborn, 2003. Equipment Rebuilds and Retrofits. Pangborn Corporation. Hagerstown, Maryland. Available online at: http://www.pangborn.com/products2.html. Accessed November 9.
Pauli RAM 31, 2001. Product information for RAM 31 Dry Stripping Cabinet. Pauli Systems Inc. Fairfield, California.
Pauli SSPC, 2001. Personal communication between representatives of Pauli Systems Inc., Fairfield, California, and Eastern Research Group, Inc., at the SSPC (Society for Protective Coatings) 2001 Conference and Exhibition. Atlanta, Georgia. November 13.
Pillar Induction Company, 2005. Personal communication between Pillar Induction Company and Eastern Research Group, Inc. January 13.
Refractory Services Provider A, 2003. Personal communications between Refractory Services Provider A and Eastern Research Group, Inc. October 6 and 7.
Robinson, S., 2001. Telephone conversation between Steve Robinson, technical specialist, American Foundry Society and Eastern Research Group, Inc. November 30 and December 3.
Schleg, F. and D.P. Kanicki, 2000. Guide to Casting and Molding Processes. Engineered Casting Solutions, Summer. Pages 18 - 27.
Scholz, R.C and J.C. Liello, 2000. A Foundry Ventilation Approach Whose Time has Come. Submitted to American Foundrymen's Society for presentation at the 2000 Casting Congress. RMT, Inc. Brookfield, Wisconsin.
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South Cast Equipment, 2000. Personal communication between Ron Brown of South Cast Equipment (distributor of Didion rotary drums) and Eastern Research Group, Inc. October 27.
Spada, A.T (Ed.), 2000. Identifying Molding Problems - A Modern Casting Staff Report. Modern Casting 90(9): 38 - 39. September.
Specialloy, 2002. Telephone conversation between a representative of Specialloy, Inc. and John L. Bennett, consultant to Eastern Research Group, Inc. February 12.
SSPC, 2001. Introduction to Water-Jetting Systems and Surface Preparation Quality Assurance (Manual for SSPC Workshop, SP-W-1). Presented at the SSPC (Society for Protective Coatings) 2001 Conference and Exhibition. Atlanta, Georgia. November 11.
Susi, P. and J. Meeker, 2008. Implementation of the OSHA Hexavalent Chromium Standard in Construction.  Presentation at the 2008 American Industrial Hygiene Conference and Exposition, Minneapolis, Minnesota, May 31 - June 5, 2008. Slides 35 through 38 on the impact of ventilation and training on hexavalent chromium exposure among construction welders.
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TAPS Grant U54 OH008307-05 Year3, 2007. Tools and Programs for Improving Occupational Health Conditions in Construction (TAPS) Project Year Three Report (July 06 - June 07). Consortium led by The Center for Construction Research and Training. Silver Spring, Maryland. August 24.
Taylor, 2001. Telephone conversation between a representative of Taylor Precision Casting, Division of American Industrial Casting, Inc., and Eastern Research Group, Inc. November.
Tricast, 2001. Telephone conversation between a representative of Tricast Corporation and Eastern Research Group, Inc. November.
U.S. Census Bureau -Copper Foundries, 2002.  2002 Economic Census for Copper Foundries (Except Die-Casting), Manufacturing Industry Series, Document Number EC02-31I-331525 (RV). Available on the U.S. Census Bureau website at https://www.census.gov/prod/ec02/ec0231i331525.pdf.
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Worldcast, 2001. Telephone conversation between representative, Worldcast Networks, Inc. and Eastern Research Group, Inc. November 2001.

SECTION 6 -- SECONDARY SMELTING, REFINING, AND ALLOYING, INCLUDING HANDLING OF SCRAP AND RECYCLED MATERIALS
Industry Profile
Workers employed in establishments performing secondary smelting, refining, and alloying of copper, aluminum, and other nonferrous materials may be exposed to beryllium. Secondary refining, smelting, and alloying establishments produce metals from scrap. These scrap materials include machine shop turnings, punchings, and borings, as well as defective or surplus metal goods (EPA 310-R-95-010). Firms also recover metals from lower grades of nonferrous scrap, including slags, ashes, residues, and mixed scrap comprised of electronic scrap, printed circuit boards and other clad materials, and metal-laden liquors.  Beryllium can be present in these types of scrap material.
Exposures to beryllium can occur both during the processing of scrap and during the smelting and alloying process. Direct handling and processing of beryllium-alloy scrap and processing of unalloyed nonferrous metals that contain trace amounts of beryllium can result in beryllium exposures (NIOSH HETA 83-162-1746, 1986). Based on the information presented in this section, OSHA has reached the preliminary conclusion that the primary potential exposure source for workers in these facilities is processing of beryllium-alloy scrap derived from electronics and computer parts and from metals recycled from defense, aerospace, and other similar applications. For the purposes of this analysis, the processing of beryllium-alloy scrap is characterized by two operations: mechanical processing and furnace operations.
The Industry Profile subsection provides an overview of the types of establishments included in this application group, while the subsections on Producers of Copper-Beryllium and Aluminum-Beryllium Alloys and Precious Metal Recovery provide, respectively, estimates of the number of establishments that produce beryllium alloys or are engaged in precious metal recovery where beryllium exposures might occur.
Industry Overview
Table IV-33 presents the 2010 County Business Patterns data on establishments in three six-digit NAICS industries: Secondary Smelting, Refining, and Alloying of Copper (331423); Secondary Smelting and Alloying of Aluminum (331314); and Secondary Smelting, Refining, and Alloying of Nonferrous Metal, Except Copper and Aluminum (331492). In 2010, 394 establishments in the United States performed secondary smelting, refining, and alloying of copper, aluminum, and other nonferrous metals. These establishments employed 15,331 workers. Nevertheless, relatively few of these firms actually handle beryllium-alloy scrap materials.
Three types of establishments in these industries -- smelters, refiners, and alloyers -- use copper, aluminum, and other scrap to produce nonferrous metal products. Low-grade copper and other nonferrous scrap require a smelting process to produce higher grades of refined metal. In smelting, the scrap is melted in a blast or rotary furnace, resulting in slag and impure copper. In the next step, refining (also known as fire refining), additional impurities are removed and the metal is cast into billets or anodes. Better grades of nonferrous metal scrap, such as copper and aluminum,  can be refined through fire refining alone, without smelting. Alloy ingot makers re-melt high-grade copper or aluminum scrap in a melting furnace along with other materials (such as metals or minerals) to produce a variety of copper and aluminum alloys.
Table IV-33 -- Secondary Smelting, Refining, and Alloying of Copper, Aluminum, and Nonferrous Metal -- 2010

         331423, Secondary Smelting, Refining, and Alloying of Copper
              331314, Secondary Smelting and Alloying of Aluminum
331492, Secondary Smelting, Refining, and Alloying of Nonferrous Metal (Except Copper and Aluminum)
                331421, Copper Rolling, Drawing, and Extruding
No. of Establishments
                                      24
                                      122
                                      248
                                      96
Total Employees
                                      789
                                     4,846
                                     9,696
                                     9,849
Source: U.S. Census Bureau, 2010; U.S. Census Bureau, 2007.

Due to environmental issues and adverse copper market conditions, many secondary copper smelters and refiners ceased operations in the early 1990s. According to published industry information, the companies currently operating in NAICS 331423 (Secondary Smelting, Refining, and Alloying of Copper) include no secondary smelters, six fire refiners (mostly tube or wire mills), and 23 copper alloyers (CDA, 2003).  While both the refiners and alloyers utilize copper scrap, only the alloyers actively seek out copper-beryllium scrap and produce copper-beryllium alloys. All three copper refiners that ERG contacted stated that they do not handle copper-beryllium scrap (Warrenton Copper, 2001; Cerro Copper, 2001; Southwire, 2001). These refiners may, however, receive and process copper scrap with trace amounts of beryllium contamination, which may be identified when the scrap is sampled.  Thus, the only companies in NAICS 331423 that deliberately handle copper-beryllium scrap materials are the alloyers.
Establishments producing aluminum-beryllium alloys from aluminum alloy scrap do generate beryllium exposures. ERG's industry contacts indicate that, among establishments in NAICS 331314 (Secondary Smelting and Alloying of Aluminum), only a few secondary aluminum smelters and alloyers handle aluminum-beryllium scrap alloys and produce aluminum-beryllium alloys. Such aluminum alloyers produce master aluminum-beryllium alloys, primarily for use as stabilizers (deoxidizers), hardeners, and grain refiners in the production of aluminum and aluminum alloys. American producers offer aluminum-beryllium master alloys that are 1.0 percent, 2.5 percent, or 5.0 percent beryllium (Diroccho; 2002; Milward, 2011).
Establishments that recover precious metals, classified in the 331492 NAICS code, may also generate beryllium exposures. However, OSHA has no exposure data to characterize the nature of beryllium exposures in this industry. Since precious metals are rarely found with beryllium, OSHA does not believe exposures in this industry may be as common as in the recovery of copper (and aluminum to a smaller extent) as copper-beryllium alloys are widely used. It is possible that some precious metal scrap may contain beryllium, such as nickel, since nickel-beryllium alloys have some industrial applications. In case exposures exist in this industry, engineering controls described in this section will be equally applicable to this industry as well as the other two industries. This is because the recovery of precious metals requires the same operations as the recovery of copper or aluminum, i.e., smelting, refining, and alloying (ingot making).
Producers of Copper-Beryllium and Aluminum-Beryllium Alloys
Based on industry contacts, a review of The Thomas Register, and Internet searches, OSHA identified six companies that currently produce copper-beryllium or aluminum-beryllium alloys.
One of these is Materion Corporation (classified in NAICS 331419, Primary Smelting and Refining of Nonferrous Metals), and another is NGK Metals (classified in NAICS 331421, Copper Rolling, Drawing, and Extruding), with a single establishment in Sweetwater, Tennessee. All of the activities performed by Materion Corporation are covered in Sections 3, Beryllium Production, and 4, Beryllium Oxide Ceramics and Composites, of Chapter IV, Technological Feasibility, of the Preliminary Economic Analysis (PEA), and are therefore not included in this section. NGK Metals also produces rolled and extruded copper-beryllium products. The activities performed by NGK Metals are covered in Section 8 -- Copper Rolling, Drawing, and Extruding, of Chapter IV of the PEA.
Three additional companies are classified in NAICS 331423, Secondary Smelting, Refining, and Alloying of Copper. One of these companies processes beryllium scrap and produces copper-beryllium alloys for specialty applications. This company has one location and 90 employees (Belmont Metals, 2001). Another company specializes in beryllium alloys and produces nickel-beryllium and aluminum-beryllium in addition to copper-beryllium (Freedom Alloys, 2005). Details about the size of this single-establishment firm were not available. The third company produces copper-beryllium alloys in the form of billets and slabs, using both scrap and purchased master ingots (90 percent copper, 10 percent beryllium) as inputs, and reports that the alloying process requires three workers on each of three daily shifts (Specialloy, 2000). The remaining company specializes in aluminum alloys and is classified in NAICS 331314, Secondary Smelting and Alloying of Aluminum. This firm reports that 10 to 15 percent of its employees are occasionally involved in aluminum-beryllium master alloy production (Mulcahy, 2002).
Although detailed employment data are not available for the four establishments specializing in beryllium alloy production (i.e., excluding Materion Corporation and NGK), Census-based industry statistics for NAICS 331423 and 331314 show an average of 40.2 and 50.4 employees per establishment, respectively (U.S. Census Bureau, 2010). NGK's employment is not known, but the average employment for NAICS 331421 (Copper Rolling, Drawing, and Extruding), where it is classified, is 103 workers. Table IV-34 summarizes employment estimates for these establishments, based on industry averages.
Precious Metal Recovery
Establishments engaged in precious metal recovery from scrap are classified in NAICS 331492, Secondary Smelting, Refining, and Alloying of Nonferrous Metal (Except Copper and Aluminum). These establishments recover precious metals from copper scrap extracted from electronics equipment and other wastes. Recovery establishments may also perform recycling and demanufacturing, and thus, may also undertake sorting, testing, and shredding processes. Recovery establishments use several methods to separate the precious metals from the copper scrap, including chemical and electrolytic separation, thermal reduction and burning, melting and pyro-metallurgic separation, and milling. The 2007 Economic Census reports 29 firms in NAICS 331492 with sales greater than $100,000 that produce "secondary precious metals and precious metal alloys." Although the exact number is unknown, OSHA estimates that about 30 establishments nationwide recover precious metals from electronic scrap and therefore, could encounter copper-beryllium alloys . Based on the average employment per establishment in this industry, OSHA estimates that these 30 establishments employ 1,173 total workers. These estimates are also shown in Table IV-34.
Table IV-34 -- Refiners and Alloyers Producing Beryllium Alloys and
Precious Metals and Alloys
                                NAICS Industry
                            Affected Establishments
                              Affected Employees
331421, (Copper Rolling, Drawing, and Extruding): Producers of Cu-Be alloys
                                       1
                                      103
331314, Secondary Smelting and Alloying of Aluminum: Producers of Al-Be alloys
                                       1
                                      40
331423, Secondary Smelting, Refining, and Alloying of Copper
                                       3
                                      99
331492, Secondary Smelting, Refining, and Alloying of Nonferrous Metal (Except Copper and Aluminum): Producers of secondary metals and precious metal recovery
                                      30
                                     1173
Total
                                      35
                                     1,414
Sources: U.S. Census Bureau, 2007; U.S. Census Bureau, 2010; OSHA estimates. See text.
Note: Excludes Materion Corporation's Elmore, Ohio, plant, and NGK Metals.

While beryllium could be encountered in other types of secondary metal recovery, OSHA found no evidence of such exposures outside of those handling copper scrap and other beryllium-containing alloys or recovering precious metals (CDA, 2003; OSHA, 2009; U.S. Census Bureau, 2007; U.S. Census Bureau, 2010). A review of beryllium samples contained in OSHA's Integrated Management Information System (IMIS) database, covering the period 1994 through 2002, shows few detectible samples for establishments not engaged in secondary copper smelting (all of which are now closed), copper refining and alloying, or precious metal recovery (OSHA, 2009). In OSHA's judgment, the establishments shown in Table IV-34 represent those in this application group affected by OSHA's proposed beryllium standard. Among the NAICS associated with this application group, the vast majority of affected establishments (and workers) are engaged in precious metal recovery (NAICS 331492 -- Secondary Smelting, Refining, and Alloying of Nonferrous Metal (Except Copper and Aluminum)).
Process Description
Secondary metal processing and recovery is the processing of metal-containing materials to recover and reuse the metal(s). The workers who process and recover metals may be broadly grouped into two major categories: mechanical process operators who handle and treat source material (i.e., break down scrap materials) and furnace operations workers who run the various heating processes for refining, melting, and casting refined metal alloy. Both groups of workers are responsible for performing housekeeping in their work areas and are also called upon to sample the scrap and intermediary materials to determine recoverable metal content. The scale of the operation and the specifics of the recovery process vary depending on the industry as well as the facility, and not all metal processing industries or facilities have the same mix of worker activities. For example, some facilities engaged primarily in alloying may not utilize recovered, recycled, or purchased scrap in their operations (i.e., these alloy ingot makers use only purchased raw materials). Table IV-35 summarizes key operations associated with secondary metal processing.
Table IV-35 -- Summary of Secondary Metal Processing Operations*
Job Category
Key Operations
Mechanical process operators
Mechanical separation
Solvent, hydrometallurgical, and other cleaning
Collecting samples of starting and intermediary materials to determine recoverable metals
Cleaning work areas
Furnace operations workers
Furnace charging; melting/smelting, reducing, and oxidizing processed scrap material (including pyrometallurgical cleaning)
Alloying and refining
Pouring/casting and finishing metal alloys (e.g., as ingots)
Collecting samples of intermediary and finished materials to determine metals content
Cleaning work area
*	Not all industries or facilities use all of the processes or operations.

Sources: Kent et al., 2007; ERG Site Visit, 2005; NIOSH EPHB 326-12a, 2008; ERG Beryllium Site 2, 2003; ERG Beryllium Site 7, 2003; EPA EIIP, 2001.
Mechanical Processing Operators
Mechanical process operators prepare scrap for melting by sorting and processing the scrap to separate the metal of interest from other metals (potentially also of interest) and from unwanted materials such as plastics, paint, oil, and dirt. The most commonly used techniques include mechanical separation using crushing and grinding machinery, centrifugation, pyrometallurgical cleaning (burning by furnace operations workers), solvent and hydrometallurgical cleaning, and heavy media separation. One or more of these techniques are used by all secondary metal processing facilities (EPA EIIP, 2001).
Mechanical separation includes sorting, shredding, crushing, pulverizing, and other mechanical methods to reduce the scrap to smaller pieces. Reducing the scrap to smaller pieces helps remove unwanted materials and concentrate the metal for additional processing. Methods used to concentrate metals include screening, magnetic removal, eddy currents, and pneumatic classification (EPA EIIP, 2001). Sometimes feed scrap is briquetted in a hydraulic press (EPA 310-R-95-010). Metal dusts, including beryllium dust, might be generated during mechanical processes.
Workers also use other methods to separate scrap from recoverable metals; however these processes are primarily wet processes. Examples include solvent cleaning used to remove oils and grease from scrap; hydrometallurgical cleaning (leaching) -- a washing step to remove water-soluble contaminants from crushed scrap; and centrifugation (rare), also to remove oils and grease from scrap. In some cases, workers use heavy-media separators containing a viscous water medium to separate high-density metal from low-density metal. No evidence exists that workers are exposed to beryllium while performing these wet processes.
Mechanical process operators are also responsible for housekeeping in their work areas and for sampling process materials before or after processing (NIOSH 326-12a, 2008; ERG Beryllium Site 2, 2003; Kent et al., 2007). The samples are analyzed to quantify the recoverable metals at key stages in the process; the preparation of such samples can involve mechanical processing activities (e.g., a sample may be taken after material is ground in a ball mill). Samples can be collected indoors or outdoors, and manually or with the use of material handling equipment, such as a fork lift truck (Corbett, 2005). In the past, sampling tasks were sometimes performed by dedicated workers (NIOSH HETA 83-162-1746).
Furnace Operations Workers
Melting separates the metals of interest from their metallic compounds and removes contaminants remaining after mechanical processing. Melting is used to make alloys and allows castings to be made from the liquid metal. Furnaces or heated crucibles are used for melting, and heat sources include fuels or electricity (EPA EIIP, 2001).
Furnace operations workers charge (load) furnaces with a mixture of pretreated scrap, flux materials, fuels, and other materials as required. The flux materials used depend on the type of metal being processed and can chemically break metallic oxide bonds to produce pure metal (chemical reduction). Flux materials may also further purify the metal by oxidizing impurities in the scrap (EPA EIIP, 2001).
Furnace operations workers can use a series of furnaces for these processes. For example, pyrometallurgical cleaning and separating is performed in furnaces intended for sweating (taking advantage of differences in melting temperature to melt specific metals out of mixed scrap) or roasting (burning other wastes out of scrap metal). As another example, copper recovery facilities use two different furnaces to produce high-purity copper.  As a third example, the zinc industry may use distillation furnaces to recover zinc and other metals.
After the metal is refined, furnace operations workers pour the molten metal from the furnace into molds that form bars, ingots, or a final product. The workers allow the metal shape to cool and then remove it from the mold. If the formed metal is a final product, the furnace operator may perform some type of finishing work, such as abrasive blasting, to remove mold sand or scale, or grinding or sanding to smooth rough edges (EPA EIIP, 2001). In some facilities, bars and ingots are sent to another facility for further alloying or to make a final product. Furnace operations workers are responsible for housekeeping duties in their work areas (Kent et al., 2007). Depending on the size of the establishment, one worker might perform all these furnace-related operations, or some of the tasks might be assigned to specialized workers.
Exposure Profile
To determine the exposure profile of secondary smelting, refining, and alloying workers, OSHA reviewed exposure data from two ERG site visits; one to a precious/base metals recovery facility and one to a facility that melts and casts beryllium-containing alloys (ERG Beryllium Site 2, 2003; ERG Beryllium Site 7, 2003). ERG also visited an electronic scrap recycling facility, although no exposure monitoring was performed (ERG Site Visit, 2005). Additionally, OSHA considered a robust dataset from a 1983 NIOSH Health Hazard Evaluation (HHE) at a precious metals refinery but determined that, due to changes in exposure controls within this industry, exposures at facilities currently engaged in precious metals recovery are not well represented by the sample results from that study (NIOSH HETA 83-162-1746). Each of these reports is summarized briefly below. Finally ERG reviewed results from three NIOSH visits to electronic recycling operations (disassembly/deconstruction facilities) conducted at federal penal institutions in 2007 and 2008, and a study of industries that handle beryllium-containing materials in France, but determined that these reports did not represent the potentially exposed populations in the United States; therefore, sample results from these sources are not included in the exposure profile (ERG Site Visit, 2005; NIOSH EPHB 326-12a; EPHB 326-15a; EPHB 326-17a; Vincent et al., 2009).
Exposure data from secondary smelters were not incorporated into the exposure profile because currently no secondary copper smelters are operating in the United States, and OSHA has no exposure data for workers at aluminum smelters or other nonferrous metal smelters. The markedly smaller share of aluminum-beryllium alloys produced in comparison to copper beryllium alloys suggests that the beryllium scrap from aluminum-beryllium alloys in the likely input stream of all smelters would be minimal. However, OSHA is not able to verify this due to the lack of exposure data from aluminum smelters.
Data Sources
ERG Beryllium Site 2 -- Precious and Base Metals Recovery Facility
ERG Beryllium Site 2 is a precious and base metals recovery facility, and is classified under NAICS code 331492. ERG investigators visited this facility in 2003 to characterize worker exposure to airborne and surface levels of beryllium (ERG Beryllium Site 2, 2003). ERG Beryllium Site 2 buys scrap materials containing precious metals (e.g., silver, gold, platinum, palladium, iridium, rhodium, ruthenium) from electronic, automotive, jewelry, metal-coating, and fabrication industries; processes the materials; and then sells the recovered metals. Lower grade materials containing precious metals are assayed (sampled and analyzed) and then shipped to an offsite smelter. ERG Beryllium Site 2 has no direct knowledge about the beryllium content of the scrap metals it processes and does not impose any beryllium limits on incoming materials. The facility process operations include material receipt and handling, mechanical preparation, granulation/shredding, thermal reduction, ball milling, screening, blending, melting, drying/grinding, and electrowinning (ERG Beryllium Site 2, 2003).
Generally, ERG Beryllium Site 2 operates one 8-hour shift per day, five days per week, 50 weeks per year. However, the thermal reduction process runs 24 hours per day (3 shifts), 5 days per week. The work force at the site consists of 75 employees (110 companywide), including approximately 18 full-time workers with potential beryllium exposure. The facility processes approximately 15 million pounds (lbs) of electronic scrap per year and was reportedly at 50 percent capacity at the time of the visit. ERG investigators reported four operations at the site with potential beryllium exposure, including shredding, thermal reduction, milling/blending, and melting. ERG conducted personal air monitoring of workers in these processes. Although some of the samples were not full-shift (4 hours rather than at least 6 hours), OSHA has nonetheless included them in the exposure profile because these samples represent part of the best available information to OSHA.
The following descriptions indicate the activities performed by workers at this site. OSHA has grouped the shredding mill and mill blend operators into the mechanical processing job category, and the thermal reduction and melting operators into the furnace operations job category.
The shredding mill operator receives cardboard containers of scrap electronic components, including printed circuit boards, crucibles, electronic modules, and telephones. Scrap material is loaded onto a shaker table with a forklift, pulled from the shaker table onto a conveyor, and passed through a hammer mill/shaker screen and ring mill/shaker screen combination that reduces the scrap to (5/8)-inch pieces. A collection box at the end of the process fills in approximately 7 to 10 minutes, is moved to storage, and then the process is repeated. Samples are collected during shredding by an automated sampling feature integrated within the process. Shredded samples undergo additional processing to determine the precious metals value of the scrap lot. Miscellaneous tasks completed by the shredding mill operator during the shift include changing the shaker screen drum, changing the baghouse drum (filtration system), housekeeping, and administrative duties (ERG Beryllium Site 2, 2003).
The thermal reduction operator loads dry components and precious metal-containing scrap, both of which may contain organic materials, into gas-fired convection furnaces that operate at 1,400F. The furnaces drive off the organics into an emissions collection system, leaving behind the precious metals for recovery. The work tasks associated with this process include loading and unloading the furnace, material transport and handling, housekeeping, and administrative duties. The process operates for three 8-hour shifts, five days per week (ERG Beryllium Site 2, 2003).
The mill/blend operator receives prepared metallic, precious metal-containing scrap in 55-gallon drums. The prepared scrap input material is received from shredding, thermal reduction, or grinding (the grinding department was not operating during the ERG visit). Scrap and intermediate powder-like products are poured, vacuum-conveyed, or at times, manually transferred from input drums or intermediate product containers through a series of processes that include ball milling, blending, and screening. After screening, two samples (about 30 to 40 ounces each) are collected from each batch of processed scrap for laboratory analysis. ERG investigators identified the screening task as a good candidate for task-specific sampling because the operator leans into the drum, and fine powder was observed escaping the local exhaust ventilation (LEV) system (ERG Beryllium Site 2, 2003).
The melting operator processes precious-metal-bearing scrap in one of three induction furnaces (250 lb, 500 lb, or 750 lb). The scrap input material is predominately metallic and relatively free of organic contaminants. The work tasks associated with this process include furnace charging, melting, sampling, mold preparation, pouring, rubbing slag from the furnace lining, ingot removal from molds, mold quenching, and mold slag removal with a compressed air needle gun. ERG investigators identified the pouring task as a good candidate for task specific sampling because metal fumes were observed escaping the LEV system (ERG Beryllium Site 2, 2003).
Controls in Place
During the site visit, ERG investigators noted the use of the following exposure controls (Corbett, 2005; ERG Beryllium Site 2, 2003), as discussed herein. Workers are required to change into company-provided work clothes/shoes and don respiratory protection before entry into restricted areas. Respiratory protection includes half-mask air-purifying respirators with HEPA filters (for all workers not in the melt shop) and loose-fitting, powered air-purifying respirators with HEPA filters (for melt shop workers, including the melting operators). Gloves (cotton/leather) are worn as necessary for abrasion/cut protection. Showers are required at the end of the work shift. Worker clean/dirty change rooms, lunch/break rooms, hygiene facilities, and personal protective equipment storage are provided by the employer. Work uniforms are laundered off site by an outside vendor. Written housekeeping procedures have been established for each department, and a central vacuum system is provided in the mill/blend department to assist with housekeeping.
LEV systems are provided to control aerosols generated by the processes. In the shredding department, LEV is provided through either partial or full enclosures on the hammer mill, ring mill, transfer conveyors, and screening stations. The thermal reduction unit is an enclosed furnace that is ducted to an afterburner and baghouse filtration system. The mill/blend processes are operated under negative pressure, with isolated product transfer and milling ducted to the central vacuum and baghouse filtration systems. The melt shop has canopy hoods installed over the furnaces to capture metal fumes during melting and pouring.
Although LEV is provided, ERG investigators observed visible emissions escaping the hoods (especially in the melting shop and milling/blending departments) and recommended that a ventilation engineering firm be used to redesign the current layout of the system (ERG Beryllium Site 2, 2003). The LEV was deemed to be less than optimal due to inappropriate hood design and lack of adequate capture. Investigators also observed open handling and transfer of powder-like materials to and from 55-gallon drums and suggested a need for work practice controls and improved particulate capture via ventilated process hoods and enclosures (Corbett, 2005).
ERG Beryllium Site 7 -- Melting and Casting Beryllium-Containing Alloys
ERG investigators visited this alloyer in 2003 to characterize worker exposure to airborne and surface levels of beryllium (ERG Beryllium Site 7, 2003). ERG Beryllium Site 7, classified under NAICS code 331421, manufacturers over 1 million lbs. of beryllium-containing casting and master alloys annually. The company manufactures copper-beryllium, aluminum-beryllium, and nickel-beryllium alloy products with beryllium content ranging from 0.35 percent to 10.5 percent. All beryllium alloys are manufactured using high-purity metallic beryllium or certified master alloys.
Casting at ERG Beryllium Site 7 is done by three workers during the night shift, with only one casting done on an average night. One or more induction furnaces are loaded with pure metal ingots and beryllium master alloy ingots (primarily by hand) from crates hoisted into place above the melting pot. All three workers are involved in removing ingots from the crates and filling up the furnace. Once the furnace is loaded, heat is applied and the melt begins. Inert gas cover and degassing technology, along with automatic furnace controls and ingot mold conveyors, are utilized for melting and casting operations. During melting, dross (metal oxides in or on the surface of molten metal) is skimmed off the surface, and the melt is sparged to ensure complete mixing (i.e., gas is introduced into the furnace to stir the melt). The majority of the shift, however, is spent in the office waiting for the melting to be completed (ERG Beryllium Site 7, 2003).
When the melt is complete, the pour begins. The furnace is tilted in place to pour the molten metal into molds. The type of mold selected depends on customer specifications and can change from pour to pour. The cast materials are allowed to cool and then are placed either by hand or with a lift truck into containers for shipment. Larger molds may be trimmed using a band saw with lubricant stream before being shipped (ERG Beryllium Site 7, 2003).