4
                                     (27%)
                                       0
                                     (0%)
                                       1
                                     (6%)
                                      15
                                    (100%)
Pickling
                                      40
                                     (85%)
                                       3
                                     (6%)
                                       4
                                     (9%)
                                       0
                                     (0%)
                                       0
                                     (0%)
                                       0
                                     (0%)
                                      47
                                    (100%)
Degreasing
                                      19
                                     (90%)
                                       0
                                     (0%)
                                       2
                                     (10%)
                                       0
                                     (0%)
                                       0
                                     (0%)
                                       0
                                     (0%)
                                      21
                                    (100%)
POWDERING
                                       8
                                     (11%)
                                      13
                                     (18%)
                                      22
                                     (31%)
                                      14
                                     (19%)
                                      11
                                     (15%)
                                       4
                                     (6%)
                                      72
                                    (100%)
Operator/Impact Grinding
                                       5
                                     (19%)
                                       1
                                     (4%)
                                       6
                                     (23%)
                                       6
                                     (23%)
                                       7
                                     (27%)
                                       1
                                     (4%)
                                      26
                                    (100%)
Compact Loading/Sintering
                                       3
                                     (16%)
                                       6
                                     (32%)
                                       5
                                     (26%)
                                       0
                                     (0%)
                                       3
                                     (16%)
                                       2
                                     (10%)
                                      19
                                    (100%)
Near Net Shape (operator & welder)
                                       0
                                     (0%)
                                       6
                                     (22%)
                                      11
                                     (41%)
                                       8
                                     (29%)
                                       1
                                     (4%)
                                       1
                                     (4%)
                                      27
                                    (100%)
CHEMICAL OPERATIONS
                                       1
                                     (5%)
                                       2
                                     (10%)
                                      10
                                     (50%)
                                       4
                                     (20%)
                                       2
                                     (10%)
                                       1
                                     (5%)
                                      20
                                    (100%)
Beryllium Sulfate Salt (GC salt and wet screen operators)
                                       1
                                     (5%)
                                       2
                                     (10%)
                                      10
                                     (50%)
                                       4
                                     (20%)
                                       2
                                     (10%)
                                       1
                                     (5%)
                                      20
                                    (100%)
FURNACE OPERATIONS
                                       8
                                     (5%)
                                      20
                                     (12%)
                                      42
                                     (24%)
                                      46
                                     (27%)
                                      25
                                     (14%)
                                      31
                                     (18%)
                                      172
                                    (100%)
Alloy Induction
                                       5
                                     (5%)
                                      13
                                     (13%)
                                      31
                                     (32%)
                                      26
                                     (27%)
                                      13
                                     (14%)
                                       9
                                     (9%)
                                      97
                                    (100%)
Alloy Arc
                                       0
                                     (0%)
                                       1
                                     (3%)
                                       6
                                     (16%)
                                      14
                                     (37%)
                                       7
                                     (18%)
                                      10
                                     (26%)
                                      38
                                    (100%)
High Beryllium Vacuum Cast
                                       0
                                     (0%)
                                       3
                                     (34%)
                                       2
                                     (22%)
                                       1
                                     (11%)
                                       2
                                     (22%)
                                       1
                                     (11%)
                                       9
                                    (100%)
High Beryllium Atomization
                                       0
                                     (0%)
                                       0
                                     (0%)
                                       0
                                     (0%)
                                       4
                                     (31%)
                                       0
                                     (0%)
                                       9
                                     (69%)
                                      13
                                    (100%)
Beryllium Oxide
                                       3
                                     (20%)
                                       3
                                     (20%)
                                       3
                                     (20%)
                                       1
                                     (7%)
                                       3
                                     (20%)
                                       2
                                     (13%)
                                      15
                                    (100%)
[a]	The beryllium production exposure profile is a summary of the 1999 full-shift PBZ (lapel-type) total beryllium exposure results for workers at the Brush Wellman, Inc., Elmore, Ohio, plant.
[b]	Full-shift sample results are based on the actual sample duration. Full-shift samples have a duration of 360 minutes or longer (in dataset, all samples are at least 400 minutes duration).
[c]	Samples were analyzed by NIOSH Methods 7102 (Beryllium and compounds, as Be) or 7300 (Elements by ICP), and the analytical LOD was reported to be 0.1 ug per filter. In the dataset received by OSHA, a value had been assigned to each sample result that was below the LOD; a sample weight of 0.05 ug (one-half the analytical LOD) was used to calculate the volume-adjusted nondetectable sample concentrations (i.e., every sample was assigned a value). Samples with results below the LOD were not identified.

Source: Brush Wellman, 2004

SECTION 4 -- BERYLLIUM OXIDE CERAMICS AND COMPOSITES
Beryllium oxide ceramics and beryllium oxide-metal matrix composites are used to manufacture materials with unique physical, thermal, and electrical properties for use in electronic equipment in the aerospace and other industries (Parsonage, 2011). The U.S. Geological Survey estimates that beryllium oxide applications accounted for more than 15 percent of the beryllium consumed in the United States in 1996 (Cunningham, 2004). Industry representatives indicate that 90 to 95 percent of beryllium oxide is used for ceramic electronic applications; the remainder is used for metal matrix composite applications (Facility A-1, 2000; Facility B-1, 2000; Facility C-1, 2000; Facility H-1, 2000; Facility I-1, 2000; Facility M-1, 2000; Facility N-1, 2000). This section focuses on the processes used to manufacture beryllium oxide ceramics and beryllium oxide-metal matrix composites.
Beryllium oxide products are prepared, shaped, and then fired by methods similar to those used with other ceramic materials, such as aluminum oxide (clay). To form the precise shapes required, manufacturers typically finish products using precision machining methods. Beryllium oxide product manufacturing involves the following categories of employees: material preparation operators, forming operators, kiln operators, machining operators, metallization workers, production support workers, and administrative staff.
Beryllium oxide-metal matrix composites are mixtures of beryllium metal and beryllium oxide created with different ratios of the two materials to obtain the desired physical, thermal and mechanical properties.  The materials are produced by blending beryllium and beryllium oxide powders into a homogeneous mixture, which is formed into blocks using processes similar to those used for beryllium ceramics.  The blocks are sliced into cards, which are then sawn to specified sizes, lapped and machined to final dimensions. The parts can then be plated with different types of metal as well.  Beryllium oxide-metal matrix composites are used primarily for aircraft and satellite avionic packaging, and represent a relatively small fraction (5-10%) of annual beryllium oxide used in the US. They are produced using similar production processes and exposure control methods as those used for beryllium oxide ceramics (Parsonage, 2011).  OSHA assumes that the control methods used for beryllium oxide ceramics will also reduce exposures when manufacturing and processing beryllium oxide-metal matrix composites.  Accordingly, OSHA's preliminary technological feasibility conclusions apply whether a particular task is performed with beryllium oxide ceramic material or with beryllium oxide-metal matrix composite material.  OSHA requests exposure data specifically associated with beryllium oxide-metal matrix composites.
The initial portion of this section describes the industries that produce beryllium oxide ceramic products, the estimated total number of establishments involved, and their employment numbers. Later portions of this section present the exposure profiles for the various categories of workers described above, as well as a discussion of the technological feasibility of reducing worker exposures in beryllium oxide ceramics and composite production activities.
Industry profile information was obtained through discussions with fabricators and finishers of beryllium oxide products, distributors of beryllium oxide raw materials, professional society board members, ceramic engineers, industrial hygienists, and research scientists. Other information sources included relevant scientific reports and trade literature. The exposure profile and technological feasibility data came from information provided to OSHA by the affected industries, from site visits to two primary beryllium oxide ceramic producers, and from discussions with industry consultants. The following paragraphs provide estimates of the number of affected establishments and the number of workers at these establishments that produce beryllium oxide ceramic and composite products.
Number of Establishments
OSHA identified only two U.S. facilities that process beryllium oxide powder into various forms for further manufacturing. This section discusses these two sites as Site 3 (ERG Beryllium Site 3, 2003) and Site 10 (ERG Beryllium Site 10, 2006: Brush Ceramic Products in Tucson, Arizona, a subsidiary of Materion Brush, Inc., formerly Brush Wellman Incorporated). These facilities are the primary beryllium oxide ceramic producers. They process "green" (unfired) beryllium oxide powder and then fire it. Thus, these facilities perform the powder material handling, pressing/forming, and kiln operations described below. They also ship beryllium oxide ceramic products as unfinished formed shapes to approximately 100 other manufacturing facilities for processing into various ceramic parts. According to reports from a major beryllium manufacturer, beryllium oxide ceramic products were sold to 102 different companies as unfinished shapes (Kolanz, 2001). OSHA estimates that 92 establishments within these 102 companies are working with beryllium oxide today. OSHA has classified these 92 establishments into eight NAICS codes. These establishments are presented in Table IV-16. Please refer to Chapter III, Industrial Profile, of the Preliminary Economic Analysis (PEA) for details on OSHA's methodology in the distribution of affected establishments within these NAICS codes.

The two primary beryllium oxide ceramic producers and the downstream establishments that fabricate porcelain electronic and electrical insulators, molded porcelain parts for electrical devices, beryllium oxide composites, and other supplies are classified in Porcelain Electrical Supply Manufacturing (NAICS code 327113).  Major customers of these facilities include aerospace and military hardware manufacturers. The 2010 County Business Patterns reported a total of 106 establishments in NAICS code 327113. The 2002 Census listed 18 of the 120 firms in this NAICS code (with shipments of $100,000 or more) as manufacturing beryllium oxide, titanate, and other ceramic electrical products and components for electronic applications (U.S. Census Bureau, 2002). These firms also engage in metallizing operations, in which a coating of metal is placed on the beryllium oxide ceramic or composite pieces, and many also perform some machining operations, such as grinding, cutting, or polishing (Pekrul, 2004). Discussions with industry personnel suggest that the actual number of domestic manufacturers of beryllium oxide ceramic products, including the primary beryllium oxide producers is less than 18 firms, possibly as low as one-half this number (Pekrul, 2004). OSHA estimates that there are 2 primary beryllium oxide producers' establishments and 14 downstream establishments in the Porcelain Electrical Supply Manufacturing NAICS code. Refer to PEA Chapter III, Industry Profile, for details on OSHA's methodology used to obtain this estimate.
Beryllium oxide ceramics are also used to produce other specialty products, such as traveling wave tubes used in microwave applications. These manufacturers braze beryllium oxide over a metal helix and assemble the tubes with finished beryllium oxide ceramic parts (Facility D-1, 2000). The 2010 County Business Patterns reports 79 establishments in the relevant NAICS code 334411 (Electron Tube Manufacturing) (U.S. Census Bureau, 2010), but industry contacts indicated that a relatively small number of firms in this industry produce traveling wave tubes using beryllium. One contact estimated that 20 to 30 companies produce these tubes (Facility J-1, 2000). Neither the 2002 nor 2007 Censuses provide disaggregated statistics regarding the number of establishments that manufacture traveling wave tubes, but the 2007 Census reported an overall total of 70 firms in this NAICS code industry (U.S. Census Bureau, 2002; U.S. Census Bureau, 2007). OSHA did not identify any other information that provided profile statistics on this group of firms, and the Agency estimates that 21 firms produce traveling wave tubes with beryllium. Refer to PEA Chapter III, Industry Profile, for details on OSHA's methodology used to obtain this estimate.
From OSHA's estimated total of 92 downstream users, this leaves 55 remaining users to be distributed among relevant industries. Based on Materion's description of customers for beryllium oxide, OSHA believes that the remaining 55 customers use beryllium oxide ceramics in the production of four types of electrical and electronic products: (1) wireless base stations (such as cell towers); (2) various electronics devices  (including resistor cores, heat sinks for satellites, and automotive ignitions); (3) medical laser devices; and (4) lasers used in entertainment devices.
Product manufacturers for these electronics products are classified in six different NAICS codes: NAICS 334415: Electronic Resistor Manufacturing; NAICS 334419: Other Electronic Component Manufacturing; NAICS 336322: Other Motor Vehicle Electrical and Electronic Equipment Manufacturing; NAICS 334220: Radio and Television Broadcasting and Wireless Communications Equipment Manufacturing; NAICS 334510: Electromedical and Electrotherapeutic Apparatus Manufacturing; and NAICS 334310: Audio and Video Equipment Manufacturing.
OSHA has preliminarily concluded that the remaining 55 customers purchasing beryllium oxide from Materion will fall within these six industries. These companies were distributed among these six NAICS codes based on Materion customer survey report descriptions and NAICS titles.
In addition, a UK company (Consolidate Beryllium Limited) also sells beryllium oxide products in the U.S. market. The customers contacted generally noted that they purchased products from Materion Corporation as well as its domestic and UK competitors. Thus, the assumption that Materion Corporation's customers represent virtually all customers in these industries should generally hold. Based on the Brush Wellman customer survey report descriptions, the Brush Wellman distribution of customers not already accounted for, and NAICS titles, the affected establishments in all of the 92 downstream users were distributed among several NAICS codes, as shown in Table IV-16. Some of the companies that work with beryllium oxide do so only occasionally (Facility B-1, 2000). Not all these establishments perform significant processing of beryllium oxide parts; some might only be assembling components.
Table IV-16 -- Distribution of Affected Beryllium Oxide Ceramic Industries by NAICS Category
                                     NAICS
                           Number of Establishments
327113	Porcelain electrical supply manufacturing
	(SIC 3264) -- Total beryllium oxide, titanate, and other ceramic electrical products and components for electronic applications, n.e.c.
                                      16
334411	Electron tube manufacturing -- Total beryllium oxide-based traveling wave tubes.
	(SIC 3671)
                                      21
334415	Electronic resistor manufacturing
	(SIC 3676)
                                      12
334419	Other electronic component manufacturing
	(SIC 3679)
                                       9
336322	Other motor vehicle electrical and electronic equipment manufacturing
	(SIC 3694 and 3714)
                                      10
334220	Cellular telephones manufacturing
	(SIC 3663 and 3679)
                                      10
334510	Electromedical equipment manufacturing
	(SIC 3845)
                                       9
334310	Compact disc players manufacturing
	(SIC 3651 and 3679)
                                       5

Total
                                      92
Sources: U.S. Census Bureau, 2002; U.S. Census Bureau, 2010; OSHA Office of Regulatory Affairs

Number of Employees
Although the Brush Wellman customer survey provides fairly current information about the number of employees in beryllium oxide-related manufacturing operations, historical data are limited.  However, the National Institute for Occupational Safety and Health's (NIOSH) 1981-1983 National Occupational Exposure Survey (NOES) offers some information. Based on survey data, NIOSH estimated that 4,305 workers were exposed to beryllium oxide in the workplace (NIOSH NOES, 1989). According to industry representatives, fewer firms are working with beryllium oxide due to its potential toxicity and the reduced availability of beryllium oxide powder, thus the number has mostly like declined since the 1980's (Facility B-1, 2000; Facility C-1, 2000; Facility D-1, 2000; Facility H-1, 2000; Facility J-1, 2000; Facility K-1, 2000; Facility L-1, 2000).
In the absence of more concrete information, OSHA estimates that the total number of affected employees is 5,722 among the 92 affected establishments. This estimate was derived from the average number of employees in an establishment in a particular NAICS code multiplied by the number of affected establishments estimated to be in this same NAICS code. The Agency may be over-counting the number of employees by using the average number of employees per establishment to estimate the total. Refer to PEA Chapter III, Industry Profile, for details on OSHA's methodology used to obtain this estimate.
Table IV-17 -- Distribution of Affected Beryllium Oxide Ceramic Employees by NAICS Category
                                     NAICS
                              Affected Employees
327113	Porcelain electrical supply manufacturing
	(SIC 3264) -- Total
	beryllium oxide, titanate, and other ceramic electrical products and components for electronic applications, n.e.c.
                                      689
334411	Electron tube manufacturing -- Total
 	beryllium oxide-based traveling wave tubes.
	(SIC 3671)
                                     1,298
334415	Electronic resistor manufacturing
	(SIC 3676)
                                      732
334419	Other electronic component manufacturing
	(SIC 3679)
                                      372
336322	Other motor vehicle electrical and electronic equipment manufacturing
	(SIC 3694 and 3714)
                                      605
334220	Cellular telephones manufacturing
	(SIC 3663 and 3679)
                                      984
334510	Electromedical equipment manufacturing
	(SIC 3845)
                                      946
334310	Compact disc players manufacturing
	(SIC 3651 and 3679)
                                      95

Total
                                     5,722
Sources: U.S. Census Bureau, 2002; U.S. Census Bureau, 2010; OSHA Office of Regulatory Affairs

Industry contacts verified that most beryllium oxide handling operations at these producers are small and suggested that the fabrication facilities are among the smaller firms in the customer population. Most establishments employ between five and 20 production workers (Facility B-1, 2000; Facility E-1, 2000; Facility G-1, 2000; Facility H-1, 2000). One firm employs 50 to 60 production workers, but not all of them work on beryllium oxide projects (Facility O-1, 2000).
Process Description
ERG visited the two primary beryllium oxide ceramics production facilities and surveyed a number of operations in which beryllium exposures are possible. For the purposes of this analysis, these facilities are identified as Site 3 (ERG Beryllium Site 3, 2003) and Site 10 (ERG Beryllium Site 10, 2006). At Site 3, ERG also conducted air monitoring. Additional information on the industry was obtained from industry consultants familiar with beryllium oxide operations (Frigon, 2004).
The first step in producing beryllium oxide ceramic products involves material preparation. Pure beryllium oxide arrives at the plant as a crystalline powder in 45-gallon drums. Material preparation operators process the raw beryllium oxide powder into formulated ceramic powders that will be used to make beryllium oxide components that meet product and customer specifications. Material preparation typically involves mixing, screening, milling, spray drying, blending, and otherwise treating the raw beryllium oxide powder and any other ingredients. Forming operators shape the beryllium oxide powder using a variety of forming methods, such as pressing and extrusion. Kiln operators then heat (fire) the formed product in a kiln or furnace at high temperatures to fuse the material into shaped ceramic products.
At subsequent stages of production, machining operators precision-cut, lathe, and grind the ceramic product to refine its shape. Fired ceramics can also be metalized by applying a metal layer that provides a bonding surface for subsequent attachment of metal parts or chips (ASME, 2002).
Some parts are machined before firing because the compacted ceramic is soft and easier to shape with machine tools. This process is termed "green machining" and includes a variety of complex (precision) machining operations, such as lapping (e.g., cylindrical, centerless, and surface grinding), dicing, and drilling, that help the manufacturer meet customers' dimensional specifications (ASME, 2002).
Production support workers perform tasks such as packaging and maintenance. These activities produce little or no beryllium dust; however, production support workers may be exposed to beryllium when they perform occasional special services, when they are co-located with production activities, or when dust is inadvertently transferred to their work areas from the production areas of the plant.
Downstream facilities that purchase beryllium oxide ceramics to manufacture custom parts for various industries do not prepare raw beryllium oxide powder or fire green ceramic materials; only the two primary beryllium oxide ceramics producers process raw beryllium oxide powder. The downstream facilities might, however, process fired ceramic products, which could consist of metallization; a second firing in a tunnel-type kiln or furnace; machining of the ceramics into precise shapes (e.g., lapping and polishing, laser machining, dicing); and other operations (Berakis, 2009).
Affected Occupations
Material Preparation Operators (Primary Beryllium Oxide Ceramics Producers Only)
Material preparation operators mix beryllium oxide powder through a series of dry and wet processing steps to create materials with the properties necessary for subsequent forming/shaping operations. The material preparation operator receives bulk beryllium oxide powder in drums and transfers the material -- either automatically or manually -- into mixing equipment to form an aqueous suspension of beryllium oxide, binder additives, and water. The bulk material is vacuum-conveyed through an isolated piping delivery system to the mixing containers (ERG Beryllium Site 10, 2006). Site 10 previously used a drum tipper to transfer powder to mixing containers, but in 1998, workers began placing the drum inside a partially enclosed local exhaust ventilation (LEV) hood when transferring powder. The operator removes the top of the drum and uses a vacuum lance to extract powder from the drum. The worker remains outside the hood with only his hands (gloved) and arms (covered in protective sleeves) inside the enclosure.
The mixing equipment is used to homogenize the aqueous suspension into a slurry. Some formulations require the operator to mill the ingredients (e.g., in a ball mill or similar equipment) to reduce the particle size as part of the mixing process. Before the beryllium oxide material is shaped using a pressed-powder process, the material preparation operator must generate a specially prepared powder by pumping the slurry to a spray dryer that disperses material under a high-pressure airstream for rapid drying inside an enclosed chamber. Spray drying prepares the beryllium oxide powder by producing a consistent particle size (essential for product quality) and reducing the moisture content so that the powder will consolidate when compressed. Material preparation workers may also screen the spray-dried powder as an added step of quality control to ensure uniform size.
At Site 3, material preparation was performed manually inside a hood, although not all operations (such as spray drying) were performed while ERG investigators were on site (ERG Beryllium Site 3, 2003). The material preparation tasks that ERG observed included powder transfer from a vendor container into intermediate milling containers and the loading of powder into the rotational beryllium oxide powdering mill. Thus, the material preparation operator was potentially exposed during manual loading and unloading of bulk product containers and the rotational mill, when disconnecting product drums from the bottom of the spray dryer, and when servicing and maintaining associated equipment.
Forming Operators (Primary Beryllium Oxide Ceramics Producers Only)
After material preparation, the next step is the forming operation, during which the beryllium oxide materials are shaped into a variety of small specialty ceramic products, ranging in size from a few millimeters to several inches). These forming operations occur at the two primary beryllium oxide ceramics producers' facilities. The forming processes include a variety of techniques common to the ceramics industry. Forming operators typically mold beryllium oxide using one of the following processes:
Dry (powder) pressing: A process in which forming operators use equipment to compress spray-dried, low-moisture beryllium oxide powder material into a die with a ram.
Isostatic pressing: An advanced powder compaction process in which hydrostatic forming equipment applies even pressure on all sides of a liquid-tight rubber die containing beryllium oxide powder to form ceramic parts.
Hot pressing: A process whereby beryllium oxide powder is simultaneously subjected to high temperature and high pressure in heated dies. This process is used for making parts with large diameters (24 inches) and limited complexity.
Extrusion: A conventional mechanical process in which moist, paste-like beryllium oxide material is forced through a shaped orifice or die. This process is used for creating thick-walled ceramic tubes, rods, and other parts with small cross-sections.
During dry pressing, the forming operator starts by connecting the automated pressing equipment to containers filled with spray dried ceramic powder produced by the material preparation operators. At Site 10, visited by ERG in 2006, the beryllium oxide powder is brought into the forming area in 12-gallon plastic bottles. With the bottle upright, the forming operator removes the bottle cap and replaces it with a second cap that includes a feed mechanism. The operator also wraps vinyl tape around the cap to ensure a good seal on the bottle top. The operator then inverts the beryllium oxide powder container (a second worker may assist with the process), allowing powder to flow into a holding bin within the press. A measured amount of powder is positioned in the die, and the hydraulic press compacts the powder to form a firm cake in the shape of the product, which is then removed by the operator or ejected into a holding tray. The forming operator will then inspect, weigh, and vacuum the products before placing them on a tray for firing or other processing (ERG Beryllium Site 10, 2006).
Some presses run automatically so that one operator can tend a number of presses. The operator generally spends most of the shift working in the immediate vicinity of the presses. On certain product lines, the forming operator might also operate a dry, abrasive cut-off saw to remove unwanted material from the shapes formed during the pressing process.
For isostatic press operations, forming operators take the bottle of prepared beryllium oxide powder and place it inside a large LEV hood. Then they remove the cap and use a vacuum wand to empty the powder into a hopper on top of the hood. From the hopper, the powder is dispensed into a liquid-tight rubber mold within the hood. The operators then immerse the mold in a noncompressible fluid (oil or water) contained in a pressure vessel. The operator pressurizes the fluid in the vessel, which causes all surfaces of the mold to receive equal pressure. The result is a molded product shape with uniform density. To release the product shape, the forming operator removes the mold from the pressure vessel and disassembles it under an LEV hood. The operator also cleans the shape by hand.
During the material preparation activities observed at Site 3, the worker performed the manual operations (including product shape-washing) inside a long, laboratory-style exhaust hood equipped with running water and both back- and downdraft exhaust air flow. After washing, the product was placed in a covered container for transfer outside the hood (ERG Beryllium Site 3, 2003). Industry information indicates that isostatic pressing is used for both ceramic and beryllium oxide-metal matrix blends (Materion, 2011).
Pressing methods might also include hot pressing. At one of the primary beryllium oxide ceramics producers' facility, beryllium oxide powder is hot pressed by simultaneously subjecting it to high temperature and pressure in heated graphite dies (ABI, 2006). Hot pressing is used only for special ceramic combination requirements.
As an alternative to pressing, the forming operator can extrude beryllium oxide material that is of a paste-like consistency. The paste is forced through a die (i.e., extruded) to form the dimensions of the product. The operator manually cuts and removes the product pieces from the die as they are being extruded and places the pieces on a product transfer cart for subsequent firing or other processing.
Overall, forming operators might be exposed to beryllium during several tasks, although the extent of potential exposure varies with the specific forming operation. The potential exposure points are when: 1) loading and connecting beryllium oxide powder material feed containers to the press, 2) loading the die with beryllium oxide powder, 3) pressing the part, 4) removing parts from the press, 5) removing excess material from the parts with a saw; and 6) unloading and disconnecting empty beryllium oxide powder product-feed containers. Additional potential exposure occurs during cleaning, service, and maintenance of the press and extrusion equipment.
Kiln Operators (Primary Beryllium Oxide Ceramics Producers and Downstream Users)
The kiln operator ensures that the kiln is working properly and that material is fired properly. Kiln operators place formed shapes inside the firing containers (called saggers). The saggers are manually placed on carts that are then rolled inside the kilns. The kiln is sealed, and formed products are fired/sintered at temperatures of 1,300°C to 1,400°C. After the firing cycle is complete (e.g., during the next shift or the next day), the kiln operator opens the kiln and wheels the cart partially out of the kiln. The cart may then be left just outside the kiln until it cools sufficiently. Kiln operators enter and leave the kiln room throughout the work shift and might also leave the area and perform other tasks while waiting for fired parts to cool.
In some cases, the flash (excess ceramic material that forms along the edge of the part at the seam where molding materials meet) must be removed from the sintered parts. Kiln operators place the parts in a large drum with water and tumble them to remove the excess material. Then the parts must be finished (by machining operators) to achieve the dimensional requirements specified for the product (Facility B-1, 2000; Facility I-1, 2000).
One firm uses beryllium oxide chips as the raw material to make traveling wave tubes. These chips can be made by machining beryllium oxide ceramic blocks or other shapes made by forming operators. In this process, kiln operators pour beryllium oxide chips into a jigged furnace with other brazing materials and then raise the temperature. The beryllium oxide brazes onto the outside wall of copper helixes, which are then suspended in airtight tubes (Facility D-1, 2000).
Machining Operators (Primary Beryllium Oxide Ceramics Producers and Downstream Users)
Machining of beryllium oxide ceramics and composites involves both large- and small-scale machining processes. Exposures occur when beryllium-containing particles become airborne as a result of the mechanical energy used to manipulate the formed shapes. In some cases, both for large- and small-scale operations, machining operators receive sintered beryllium oxide shapes in the form of blocks that must be shaped to precise sizes. For larger scale machining jobs, machining operators might oversee automated electrostatic discharge machines. These enclosed machines use jigs that operate under water to convert large ceramic blocks received from kiln operations into finished shapes. In other cases, machining operators receive the ceramics in "near-net-shapes" that require only small-scale machining to meet final product specifications. Such small-scale machining processes include grinding, lapping, drilling, laser cutting/scribing, trimming, diamond dicing, water cutting, sanding, abrasive cutting, polishing, and chemical etching.
Machining operations may also be conducted with slurry-cutting machines. Once the product is machined, operators can then mill the emerging shapes with a diamond cutter and, when necessary, use a hole-burning machine.
Machining operators typically use wet methods and ventilation for machining fired ceramics (in contrast, green machining is typically performed dry). The operator manually loads the beryllium oxide products into the machining centers. Finished parts are manually removed from the machining centers, cleaned, and placed in holding containers. Some beryllium oxide operations use lasers for scribing onto beryllia plates that would be formed by a press. Although scribing is no longer performed at Site 10, at one time this facility used enclosed carbon dioxide lasers for scribing. The laser chamber had interlocking doors and was under LEV. The laser head moved down into the enclosure to operate, and the beryllium oxide piece was on a movable platform; once in position, the laser head was fixed and the part was moved (ERG Beryllium Site 10, 2006).
At Site 3, investigators observed precision grinding operations on beryllium oxide ceramic material parts. The precision grinding machining operator was running a surface grinder, which was fully enclosed and under LEV. The operator performed the cutting action as a wet process, under a flood of coolant. The worker positioned the part in the grinder enclosure, cycled the machine to cut the part (cycle time was approximately 3 minutes), and removed the part when the cycle was complete. Then, the machining operator rinsed the part in a tray of water, wiped it off with a sponge, and placed it in a parts tray. Both manual and automatic grinding techniques are used to achieve precise physical dimensions. Another available method in the shop includes cylindrical grinding. This grinding method used diamond wheels to machine a solid or hollow cylinder and is capable of removing material from any surface are of the cylinder. This technique can be performed dry (green machining) or wet through the application of metalworking fluid.
Additional discussions of precision machining (for beryllium and beryllium alloy products) are provided in Section 7 -- Precision Turned Products. In general, the machining of beryllium oxide ceramics is similar to machining of other beryllium materials (e.g., alloys). OSHA has no evidence that allows a comparison of the relative hazards of machining on beryllium oxide ceramics or metallic beryllium materials, although the hazards are thought to be similar. Beryllium oxide ceramic materials might generate more particulate during machining because the ceramics are more easily reduced to dust than solid beryllium metal, but this has not been confirmed in the technical literature. In general, the same control measures are applied to machining beryllium oxide, metallic beryllium, and beryllium alloy materials.
Metallization Workers (Primary Beryllium Oxide Ceramics Producers and Downstream Users)
Some beryllium oxide ceramics and composites are metallized, which involves plating or brazing with metal to permit the joining of the ceramic part to other pieces of equipment. Because the beryllium oxide ceramics are being coated but not cut or degraded in this step, there is generally no beryllium exposure during this process.
The manufacture of laser bores exemplifies metallization work. During the manufacture of laser bores, workers first place the part in an enclosed metallizing machine and then take the part to a small kiln to bake on the metallization. Thus, these workers rotate among metallizing and kiln operations. They also transfer the parts to the lapping department as needed.
Production Support Workers (Primary Beryllium Oxide Ceramics Producers and Downstream Users)
This category includes packaging and maintenance jobs. Packaging workers receive finished parts from the production area, perform visual/dimensional inspections, and then package the products for shipment. Maintenance involves all types of repair tasks on production equipment and facilities, as well as janitorial work.
Administrative Staff (Primary Beryllium Oxide Ceramics Producers and Downstream Users)
This category includes front office, engineering, and research and development staff. These workers typically do not handle beryllium products directly during the manufacturing process, nor do they perform tasks that might generate beryllium dust. Some facilities allow administrative staff to pass through production areas or perform activities co-located near production areas, but others do not (ERG Beryllium Site 3, 2003; ERG Beryllium Site 10, 2006). Beryllium dust might also unwittingly be transported from production areas to administrative workspaces on paper, clothing, and other items, although facilities have taken measures to prevent transfer to nonproduction areas, as discussed below.
Number of Workers by Job Category
Table IV-18 presents the distribution of beryllium oxide ceramic workers by job category. This distribution is based on information obtained during ERG's site visit to a primary beryllium oxide ceramics producer facility (Site 3 and Site 10) and from discussions with project consultants and other industry contacts (ERG Beryllium Site 10, 2006; ERG Beryllium Site 3, 2003; Frigon, 2004, 2005; Kolanz, 2001).
Table IV-18 -- Number of At-Risk Beryllium Oxide Workers by Job Category
Job Category
                               Number of Workers
                                    Percent
Material Preparation Operators
                                       8
                                     0.6%
Forming Operators
                                      63
                                     4.9%
Kiln Operators
                                      22
                                     1.7%
Machining Operators
                                      433
                                     33.6%
Metallization Workers
                                      66
                                     5.1%
Production Support
                                      208
                                     16.1%
Packaging Operator
                                      14
                                     1.1%
Maintenance
                                      169
                                     13.1%
Janitor
                                      25
                                     1.9%
Administrative Staff
                                      489
                                     38.0%
Total
                                     1,289
                                    100.0%
Sources: ERG Beryllium Site 3, 2003; ERG Beryllium Site 10, 2006; Frigon, 2004, 2005; Kolanz, 2001

Exposure Profile
Data Sources
Four sources of exposure measurement data were used to determine the exposure profile for the beryllium oxide ceramic industry:
1.          Personal breathing zone (PBZ) (lapel-type) air-sampling results taken between 1994 and 2003 at Site 10, a large beryllium oxide ceramics facility (OSHA-H005C-2006-0870-0094). The docket submittal was made by Brush Wellman in 2003 and is presumed to represent exposure data from the facility termed Site 10 in this technological feasibility analysis.
         A published report that provides information on beryllium oxide ceramics product manufacturing for a slightly earlier time period at Site 10 (Kreiss et al., 1996).
         PBZ and hand/surface contamination results obtained during a site visit to a primary beryllium oxide ceramics producer (Site 3).
         PBZ exposure data from OSHA's Integrated Management Information System (IMIS) (OSHA, 2009).
No exposure information was obtained specifically for beryllium oxide metal composites, however, OSHA assumes that the potential for exposure is similar for both ceramics and composites.
The majority of the full-shift PBZ air-sampling results are from data associated with beryllium oxide operations at Site 10. Additional PBZ air-sampling results were collected during the visit to Site 3. OSHA acknowledges that the exposure profile for this sector might not represent the entire industry because it is primarily based on the results of one facility (Site 10); however, it represents the best available data. It is possible that the exposure profile might overestimate current exposures for some job categories at Site 10 because the facility has reportedly made enhancements to engineering, work practice, and migration controls since the samples were taken. It is also possible that the exposure profile underestimates potential exposures at other firms in this sector that might not have the level of controls employed at Site 10 or Site 3. However, no downstream users handle beryllium oxide powder or fire green materials, two processes that have high exposure potential.
The sampling results are organized into the seven major job categories described in the Process Description sub-section (i.e., material preparation operators, forming operators, kiln operators, machining operators, metallization workers, production support workers, and administrative staff).
ERG Beryllium Site 10 (1994 - 2003)
Exposure data includes 1,214 full-shift PBZ beryllium sample results obtained from 1994 through 2003 for workers at Site 10. These exposure data for Site 10 are included in unpublished data provided to ERG (Brush Wellman Tucson, 2004). Although the sample results were obtained over a 10-year period, nearly 50 percent of the samples were collected in 2001, when production levels peaked. All results were obtained while workers produced beryllium oxide ceramic products, so all results are associated with essentially 100 percent beryllium oxide.
Air samples were analyzed by NIOSH Method 7102 (Beryllium and compounds, as Be) or 7300 (Elements by ICP). The analytical limit of detection (LOD) was reported to be 0.1 micrograms (ug) beryllium per filter, which corresponds to an airborne concentration of approximately 0.1 ug/m[3] for an 8-hour sample. For sample results below the LOD, a sample weight of 0.05 ug (one-half the analytical LOD) was used to calculate the volume-adjusted, nondetectable sample concentration. (For further information on the handling of nondetectable samples, see the discussion in Section 2 -- Methodology.) All samples are full shift and represent a minimum sampling duration of at least 400 minutes. Sample concentrations are based on the actual sampling durations rather than 8-hour time-weighted averages (TWAs).
Earlier Information on Site 10 (Prior to 1994)
Kreiss et al. (1996) provide additional information and commentary on airborne exposures at the Site 10 facility. As noted, the publication does not name the facility under study, but NIOSH's beryllium research newsletters identify it as the facility termed Site 10 in this technological feasibility analysis (NIOSH Beryllium Research, 2005). Kreiss et al. addressed a time period earlier than that represented by the exposure profile data (i.e., prior to 1994). The purpose of the earlier study was to examine the risk of beryllium disease and sensitization among workers with median exposures below 2.0 ug/m[3]. The researchers noted that the occasional exposures over 2.0 ug/m[3] occurred primarily in machining operations. The Kreiss et al. (1996) investigation did not find the same level of exposures (e.g., > 1.0 ug/m[3]) for material preparation workers as the exposure data used here. The authors stated that their study of general area and PBZ samples for this beryllium oxide ceramics facility indicated that exposures had been decreasing over the 12 years of plant operation prior to the time of the study (Kreiss, 1996). OSHA did not incorporate these exposure results because the study reported their findings as summary rather than individual data. Additionally, modifications have been made to this facility since this study, so these samples would not be representative of current conditions. More recent information is used in the exposure profile instead.
ERG Beryllium Site 3
Four full-shift PBZ total beryllium air samples were collected during a visit to Site 3 (2003). OSHA's Salt Lake City Laboratory performed the laboratory analyses. Beryllium mass was determined using OSHA Method No. ID-125G, inductively coupled argon plasma - atomic emission spectroscopy. Field and media blanks made up 10 percent and 5 percent of the samples analyzed, respectively. The analytical reporting limit for air samples was 0.02 ug beryllium per filter. The four full-shift samples are included in the exposure profile.
During this site visit, an attempt was made to survey as many of the potential beryllium-handling activities as possible. Due to weak product demand at the time of the visit, however, the facility was operating at only 10 percent of capacity. Sample results were obtained from the four workers participating in the beryllium oxide operations at the time of the ERG visit (i.e., all workers potentially exposed to beryllium oxide were sampled; the workers were engaged in material preparation, forming, and machining). All four of the air-sampling results were 0.1 ug/m[3] or less. ERG's investigators noted that these results were due to well-practiced work procedures for keeping beryllium oxide dust within the process enclosures and ventilation hoods, diligent housekeeping, and process enclosures designed to promote effective cleaning (e.g., stainless steel framed/Plexiglas construction; hoods with running water, drains, and both back- and downdraft airflow designs; minimization of horizontal surfaces inside hoods). Based on the results of the air-sampling data, these efforts appeared to be successful at containing airborne particulates.
In addition to taking full-shift samples, ERG investigators measured short-term worker exposures during two tasks, each of which has relatively high potential for beryllium exposure. The task-specific samples represent a more focused examination of exposures that occur during individual tasks primarily associated with the job category. One measurement was taken for a material preparation operator and another for an isopress forming operator. These short-term samples provide further evidence that the operations sampled were well controlled: both of these results are below the analytical LOD (in this case 0.01 ug/m[3] for the material preparation operator and  0.004 ug/m[3] for the forming operator). The two task samples were not used in the personal exposure profile because they are not full-shift samples and were not collected using a validated sampling method. In an attempt to meet the minimum air volume required to detect the presence of beryllium, the task samples were collected at a high flow rate of 25 liters per minute (lpm) (ERG Beryllium Site 3, 2003). In contrast, the flow rates specified for validated OSHA and NIOSH sampling methods range from 1 lpm to 4 lpm.
The beryllium concentrations were low for both personal full-shift and task samples obtained during this survey. The dust collected in these samples generally contained less than 1 percent beryllium, indicating that the beryllium oxide handled at the plant was controlled sufficiently enough to severely limit beryllium dust during material transfer in material preparation, and during pressing operations to form beryllium oxide shapes.
OSHA IMIS Database
Only 14 results of a total of 317 PBZ samples in the IMIS database had detectable beryllium (OSHA, 2009). These data are characterized by a median of 0.18 ug/m[3], a mean of 0.54 ug/m[3], and a range of 0.05 ug/m[3] to 2.0 ug/m[3]. The sampling results in which beryllium was detected are associated with racing engine manufacturing (one sample, 0.26 ug/m[3]); soldering (five samples ranging from 0.1 ug/m[3] to 1.0 ug/m[3]); welding (seven samples ranging from 0.05 ug/m[3] to 2.0 ug/m[3]); and maintenance (one sample, 0.2 ug/m[3]). Nearly all the positive IMIS results are older (i.e., from 1981 to 1991) than the other exposure data available (i.e., prior to 1994, 1994 to 2003, 2003). Only one sample is relatively recent and was obtained in 2006 (reported in IMIS as racing engine manufacturing sample). Interpretation of the IMIS results is limited because the data do not report the sample durations, the exact circumstances of the sampling, or the analytical LOD. Because of these limitations, the IMIS data provide supporting data but are not included in the exposure profile.
Personal Exposure Profile for Beryllium Oxide
Tables IV-19 and IV-20 represent the exposure profile for beryllium oxide ceramics industry workers. Table IV-19 presents the number, range, mean, and median of the samples by job category. Table IV-20 presents the distribution of the results by job category in relation to the proposed permissible exposure limit (PEL) options of 0.1 μg/m[3], 0.2 μg/m[3], 0.5 μg/m[3], and 1.0 μg/m[3].
Table IV-19 -- Details of Personal Exposure in the Beryllium Oxide Ceramics Industry (1994 - 2003)
                               Job Category and
                                  Work Group
                             No. of Full-Shift PBZ
                                  Samples[a]
                                     Range
                                  (μg/m[3])
                                     Mean
                                  (μg/m[3])
                                    Median
                                  (μg/m[3])
Material Preparation Operator
                                      77
                                 0.02 to 10.6
                                     1.01
                                     0.41
Forming Operator[b]
                                      408
                                 0.02 to 53.2
                                     0.48
                                     0.18
Kiln Operator
                                       3
                                 0.22 to 0.36
                                     0.28
                                     0.25
Machining Operator
                                      355
                                  0.01 to 5.0
                                     0.32
                                     0.15
Metallization Worker
                                      36
                                 0.02 to 0.62
                                     0.15
                                     0.06
Production Support Worker
                                      119
                                  0.02 to 7.7
                                     0.21
                                     0.05
Packaging Operator
                                      37
                                 0.020 to 0.50
                                     0.09
                                     0.05
Maintenance
                                      81
                                 0.02 to 7.70
                                     0.26
                                     0.05
Janitor
                                       1
                                     0.80
                                     0.80
                                     0.80
Administrative Staff
                                      185
                                  0.02 to 1.2
                                     0.06
                                     0.05
Total
                                     1,218
                                 0.01 to 53.2
                                     0.36
                                     0.11
[a]	The exposure profile is based on full-shift PBZ (lapel) total beryllium sample results. Full-shift sample results represent a sampling duration of 360 minutes or longer and have not been time-weighted for 8 hours (i.e., full-shift sample results are based on the actual sampling duration). Most samples (1,214 samples) were analyzed by NIOSH Method 7102 (Beryllium and compounds, as Be) or 7300 (Elements by ICP), and the analytical LOD was reported to be 0.1 ug beryllium per filter. For sample results below the analytical LOD, a sample weight of 0.05 ug (one-half the analytical LOD) was used to calculate the volume-adjusted nondetectable sample concentration. Four samples were analyzed using OSHA Method 125G, with a reporting limit of 0.02 ug per filter. Results reported as less than 0.02 ug are incorporated into the exposure profile as volume-adjusted reporting limit concentrations.
[b]	Twenty-eight samples (7 percent of all forming operator samples) associated with tape casting are included, although tape casting is not currently performed.

Sources: Brush Wellman Tucson, 2004 (presenting data for ERG Beryllium Site 10); ERG Beryllium Site 3, 2003.

Table IV-20 -- Distribution of Full-Shift PBZ Exposure Results for Total
Beryllium in the Beryllium Oxide Ceramics Industry (1994 - 2003)
                               Job Category and
                                  Work Group
             Number of Full-Shift PBZ Sample Results in Range [a]
                                  (μg/m[3])
                                     Total
                                    No. of
                                    Samples

                                   < 0.1
                                  <= 0.1 to
                                    <= 0.2
                                  > 0.2 to
                                    <= 0.5
                                  > 0.5 to
                                    <= 1.0
                                  > 1.0 to
                                    <= 2.0
                                   > 2.0

Material Preparation Operator
                                      10
                                     (13%)
                                      12
                                     (14%)
                                      24
                                     (33%)
                                      15
                                     (20%)
                                       8
                                     (10%)
                                       8
                                     (10%)
                                      77
                                    (100%)
Forming Operator [b]
                                      110
                                     (27%)
                                      118
                                     (29%)
                                      115
                                     (28%)
                                      43
                                     (11%)
                                      15
                                     (4%)
                                       6
                                     (1%)
                                      408
                                    (100%)
Kiln Operator
                                       0
                                     (0%)
                                       0
                                     (0%)
                                       3
                                    (100%)
                                       0
                                     (0%)
                                       0
                                     (0%)
                                       0
                                     (0%)
                                       3
                                    (100%)
Machining Operator
                                      142
                                     (37%)
                                      102
                                     (26%)
                                      87
                                     (22%)
                                      40
                                     (10%)
                                      11
                                     (3%)
                                       8
                                     (2%)
                                      390
                                    (100%)
Metallization Operator
                                      20
                                     (55%)
                                       5
                                     (14%)
                                      10
                                     (28%)
                                       1
                                     (3%)
                                       0
                                     (0%)
                                       0
                                     (0%)
                                      36
                                    (100%)
Production Support Worker
                                      81
                                     (68%)
                                      24
                                     (20%)
                                       8
                                     (7%)
                                       3
                                     (2%)
                                       1
                                     (1%)
                                       2
                                     (2%)
                                      119
                                    (100%)
Packaging Operator
                                      27
                                     (73%)
                                       8
                                     (22%)
                                       2
                                     (5%)
                                       0
                                     (0%)
                                       0
                                     (0%)
                                       0
                                     (0%)
                                      37
                                    (100%)
Maintenance
                                      54
                                     (67%)
                                      16
                                     (20%)
                                       6
                                     (8%)
                                       2
                                     (2%)
                                       1
                                     (1%)
                                       2
                                     (2%)
                                      81
                                    (100%)
Janitor
                                       0
                                     (0%)
                                       0
                                     (0%)
                                       0
                                     (0%)
                                       1
                                    (100%)
                                       0
                                     (0%)
                                       0
                                     (0%)
                                       1
                                    (100%)
Administrative Staff
                                      172
                                     (93%)
                                       9
                                     (5%)
                                       2
                                     (1%)
                                       1
                                    (0.5%)
                                       1
                                    (0.5%)
                                       0
                                     (0%)
                                      185
                                    (100%)
Total
                                      535
                                     (44%)
                                      270
                                     (22%)
                                      249
                                     (20%)
                                      103
                                     (9%)
                                      36
                                     (3%)
                                      25
                                     (2%)
                                     1,218
                                    (100%)
[a] 	The exposure profile is based on full-shift PBZ (lapel) total beryllium sample results. Full-shift sample results represent a sampling duration of 360 minutes or longer and have not been time-weighted for 8 hours (i.e., full-shift sample results are based on the actual sampling duration). Most samples (1,214 samples) were analyzed by NIOSH Method 7102 (Beryllium and compounds, as Be) or 7300 (Elements by ICP), and the analytical LOD was reported to be 0.1 ug beryllium per filter. For sample results below the analytical LOD, a sample weight of 0.05 ug (one-half the analytical LOD) was used to calculate the volume-adjusted nondetectable sample concentration. Four samples were analyzed using OSHA Method 125G, with a reporting limit of 0.02 ug per filter. Results reported as less than 0.02 ug are incorporated into the exposure profile as volume-adjusted reporting limit concentrations.
[b] 	Twenty-eight samples (7 percent of all forming operator samples) associated with tape casting are included, although tape casting is not currently performed.

Sources: Brush Wellman Tucson, 2004 (presenting data for ERG Beryllium Site 10); ERG Beryllium Site 3, 2003.

OSHA has reviewed data for each of the major process steps at beryllium oxide ceramic operations for both a large industrial setting and a small facility setting. Site 10 is the only fairly large operation in this sector, so the findings may have limited applicability to other facilities. The operations observed at Site 3 are judged to be reflective of well-designed operations at a small job facility. Accordingly, the Site 3 observations are assumed to be applicable to other beryllium-oxide-using customers of these facilities. The low level of operations observed at Site 3, however, might underestimate the exposures for the broader population of beryllium oxide machining and other operations. Thus, average exposures for typical beryllium oxide machining and other operations might be higher than those at Site 3.
As shown in Table IV-19, the median values are below the mean for all job categories, reflecting the occasional high measurements obtained for some job categories. Table IV-20 also shows that exposures exceeding 1.0 ug/m[3] have occurred in most job categories (with the exception of kiln operators and metallization). However, other than material preparation operators and kiln operators, the median values for each job category fall within the range of 0.05 ug/m[3] to 0.2 ug/m[3].
A limited number of facilities are involved in beryllium oxide ceramic production. The two facilities (Site 3 and Site 10) for which exposure observations were obtained represent the primary commercial activity involving beryllium oxide ceramic powder preparation and firing of "green" materials. Thus, the exposure profile is the best estimate of baseline exposure levels for those jobs unique to the primary beryllium oxide ceramic producers, such as material preparation and forming operators (i.e., employees working with unfired beryllium oxide ceramic powder). These plants and the customers of these primary beryllium oxide ceramics producers might perform additional firing and processing of the ceramic material, such as metallization, lapping and polishing, and laser machining and dicing.
Technological Feasibility
This section presents the general and operation-specific exposure controls used in beryllium oxide ceramic and composite facilities and possible additional controls that could further reduce worker exposures.
Material Preparation Operators
Material Preparation Operators--Baseline Controls
Material preparation operators convert pure beryllium oxide powder into a paste or powder having the necessary consistency and chemistry to be formed into various shapes to meet product specifications. Potential exposures occur while unloading bulk product containers; disconnecting product drums from the spray dryer or material transfer equipment; and cleaning, servicing, and maintaining associated equipment.
Engineering controls for material preparation operations include installing partially enclosed LEV hoods at material transfer points (e.g., unloading beryllium oxide powder from containers or drums, connecting/disconnecting collection containers at the base of the spray dryer) and using fully enclosed and ventilated material transfer systems to convey material from one process step to another (e.g., material screening, milling, storage). Other controls include careful work practices, wet cleaning methods (for housekeeping and equipment cleaning), and frequent housekeeping.
The two facilities that include primary beryllium oxide production processes utilize substantial LEV and operating enclosures. At Site 10, the material preparation operation is located in an isolated room and is separated from the rest of the plant by an airlock. To transfer material from product-feed drums to the holding bins, the material preparation operator reaches into a partially enclosed transfer hood to open product feed drums and vacuum-convey (through the use of a vacuum wand) beryllium powder through an enclosed system into the holding bin. Workers remain outside the hood; only their arms, which are covered with protective sleeves, enter open drums to manipulate the vacuum wand during transfer of the powder (ERG Beryllium Site 10, 2006).
Similarly, all powder-transfer tasks are performed in a partially enclosed LEV hood or containerized in a seal-tight enclosure. ERG observed highly disciplined work practices. The material preparation operator cleans all potentially contaminated surfaces (e.g., containers, bags, gloves, hands, skin) with running water and sponges before removing them from the exhaust hood. Hoods are engineered for easy cleaning (e.g., stainless steel and Plexiglas construction, minimization of horizontal surfaces), with clean running water and drainage capability to facilitate cleaning before anything is removed from the hood. The material preparation operator also performs general housekeeping tasks.
Site 10 has made changes to specific equipment and processing techniques over time to reduce exposures (ERG Beryllium Site 10, 2006). First, facility personnel reorganized production so that similar ceramic mixes are processed in sequence, reducing the frequency of worker cleanouts of the spray-drying equipment. Currently, during routine production, the spray dryer is reportedly cleaned two to three times per week. The amount of time spent cleaning typically ranges from 15 to 30 minutes (ERG Beryllium Site 10, 2006). Much of the operator exposure associated with this task occurs when the worker leans over and/or into the dryer hatch for cleaning. The spray-dryer operating action was modified to reduce the amount of material left in the equipment after a production cycle. The facility reported that the reconfiguration had reduced the amount of material left in the spray dryer by a factor of 6 or 7. Further, the facility changed the spray-dryer cleaning method from hand scraping to wet cleaning with a pressure washer. The facility reported that the combination of changes decreased cleaning frequency overall and reduced exposures during cleaning (ERG Beryllium Site 10, 2006); however, no data were available to estimate the extent of the reduction.
Additionally, spray drying occurs in a segregated portion of this particular plant. Specially designed valves and LEV control the release of beryllium oxide ceramic particles when the operator disconnects the drums of prepared material from the bottom of the spray dryer. As an added precaution, operators use impermeable gloves and disposable sleeves and coveralls when breaking the plane of exhaust-hood enclosures. Impervious body aprons are worn when workers are likely to contact solutions containing beryllium oxide ceramic material.
Housekeeping is a critical part of overall exposure control. Housekeeping practices have been enhanced in recent years. At Site 3, the facility has a documented housekeeping schedule (daily, weekly, monthly, and quarterly), and activities are tracked to ensure that housekeeping requirements are completed. The site employs one full-time maintenance worker who is dedicated to and responsible for completing the housekeeping schedule. All operators are responsible for keeping their work surfaces and themselves clean throughout the shift, and they are to use the last 15 minutes of the shift to perform a thorough cleaning of their work areas. One central vacuum system and four portable HEPA filter vacuums are available to facilitate housekeeping efforts (ERG Beryllium Site 3; ERG Beryllium Site 9). Since 2000, Site 10 has also made housekeeping improvements in accordance with the Materion Worker Protection Model discussed in this PEA at Chapter IV, Methodology Appendix 1.  Site 10 housekeeping procedures now include daily housekeeping requirements by all shifts in addition to more in-depth cleaning of production areas on a monthly basis.  Cleaning must be conducted with either HEPA-filtered vacuums or wet methods (wet mop stations or automated floor cleaning machines).  Wet mop stations are designed so that floor mops can be rinsed with clean water every time.
Material Preparation Operators--Additional Controls
As shown in Table IV-19, the median exposure level (exposure profile) for material preparation operators is 0.41 ug/m[3] and the mean is 1.01 ug/m[3]. Table IV-20 indicates that 13 percent (10 of the 77 total) sample results for material preparation operators are less than 0.1 ug/m[3] and 73 percent are greater than 0.2 ug/m[3]. Therefore, additional controls will be required to achieve lower levels of exposure.
OSHA notes that the exposure profile for material preparation operators is primarily based on 10 years of exposure data (1994 to 2003). Information pertaining to worker activities is not available for these data, and there are inconsistencies in the number of samples obtained each year. For example, for both 1994 and 1995, only one sample result is available. For 2002 and 2003, four and five sample results, respectively, were obtained (compared to over 30 results obtained in 2001). Furthermore, in most cases OSHA is not able to match exposure data with the information on engineering controls obtained from Site 10, which is the most robust data source for this industry (ERG Beryllium Site 10, 2006). Thus, for most samples in the exposure profile, the Agency does not have the information necessary to correlate exposure results with tasks performed and controls in place at the time of sampling from 1994 through 2003. An exception, however, does exist as described in the following paragraphs.
OSHA does have one sample (obtained at Site 3) for which the Agency has obtained detailed information on the tasks performed and specific engineering controls in place at the time of sampling. This result was reported as < 0.02 ug/m[3]. As discussed previously, this facility was operating at 10 percent of capacity, and the material preparation operator sample did not perform all the tasks associated with the job description. Specifically, this worker did not perform spray drying or maintenance of the spray chamber.
Despite this limitation of the available sample data, based on information about the tasks performed and engineering controls in place at the time of sampling, OSHA is able to infer the extent to which engineering controls are efficient for managing exposures during the specific tasks performed when this sample was taken. At the time of sampling, the Site 3 worker transferred beryllium oxide powder from vendor containers to intermediate milling containers and then to a powdering mill. ERG investigators noted that this sample result was associated with process enclosures, ventilation hoods, and diligent housekeeping (ERG Beryllium Site 3, 2003). These findings are consistent with the information provided by the Site 10 personnel regarding exposure controls at the Site 10 facility (ERG Beryllium Site 10, 2006).
The correlation between controls used at Site 3 and Site 10 is significant because key sources of worker exposure at both sites occur during material transfer and container-filling operations. The information from Site 3 offers evidence that activities involving material transfer points that require workers to handle and manipulate beryllium oxide powders and to fill containers can be well controlled by the control methods in place at Site 3 (i.e. process enclosures, ventilation hoods, and diligent work practices, including housekeeping). OSHA has evidence that facilities performing these tasks in this manner can achieve exposure levels below 0.1 ug/m[3] (ERG Beryllium Site 3, 2003). OSHA notes that other controls are also available for these processes, and recommends that the enclosed transfer hood where drums are emptied be equipped with a solid door with a viewing port and gloves. Workers typically must stand immediately outside the hood while reaching into the hood to remove the lid, operate the vacuum wand, and clean the container and the inside of the hood. A solid door with viewing ports extending into the hood would provide a physical barrier separating the operator from the source of contamination. For small-scale operations where smaller containers are emptied, ventilated glove boxes, such as those shown to reduce exposures to pharmaceutical chemicals to 0.1 ug/m[3], would likely be an effective control measure (Hosokawa Micron Group, 2005).
As noted above, documentation indicates that controls similar to those in place at Site 3 (process enclosures, ventilation hoods, and diligent housekeeping) were also in use at Site 10. The information from Site 3 does not, however, offer information on exposures that occur during spray drying or maintenance of the spray drier, tasks that OSHA infers were routinely conducted at Site 10 during the periods sampled.
Although OSHA does not have exposure data specific to spray drying, spray drying operations can be conducted in an enclosure (ERG Beryllium Site 10, 2006).  Therefore, to the extent this isolation method works effectively, OSHA anticipates that exposures during spray drying operations can be maintained below 0.1 ug/m[3].
OSHA does not have evidence that exposure levels below 0.2 ug/m3 can be achieved on shifts when workers perform maintenance of the spray chamber. Despite information from the Site 10 facility regarding improvements during maintenance of the spray chamber, no exposure data demonstrate the effect of these modifications on worker exposures. Based on the information presented here, OSHA acknowledges that maintenance of the spray chamber is potentially the greatest source of exposure for material preparation operators. The exposure profile suggests that this task contributes significantly to exposures and was performed routinely during sampling at Site 10. Despite having only limited information about the tasks performed, OSHA did obtain a description of the process indicating that, during normal operations, maintenance of the spray chamber was typically performed for approximately 30 minutes three days per week (e.g., after each production run) because the material tends to clump in the bottom of the spray drier and must be removed regularly (ERG Beryllium Site 10, 2006). Additionally, as described in the process description for this industry, spray drying is an essential step in producing beryllium oxide powder, therefore the frequency of spray drying (and related equipment servicing and maintenance) must increase as beryllium oxide powder production increases. Furthermore, OSHA knows, from site personnel and reported sampling dates, that nearly 50 percent of the Site 10 samples were collected in the year 2001, a period when production levels were near peak (i.e., a time when spray drying was by necessity commonplace due to high production demand). From this information, OSHA finds it reasonable to infer that spray dryer maintenance was regularly included in activities sampled in 2000 and 2001.
In summary, sampling data indicate that exposure from transferring and filling operations can be minimized with adequate controls because an exposure measurement taken when only these tasks were performed (i.e., when no spray drying or spray dryer maintenance were conducted) was below 0.1 ug/m[3]. OSHA also believes exposures during spray drying can be maintained at or below 0.1 ug/m[3] because spray drying occurs in a ventilated enclosure. However, despite these controls for transferring, filling, and spray drying operations, the exposure profile shows that 73 percent of exposures remained elevated (above 0.2 ug/m[3]). Therefore, OSHA preliminarily concludes that primary source of exposures above 0.1 ug/m[3] for material-handling operations is maintenance of the spray chamber. This task is performed for approximately 30 minutes three days per week, which means that this task causes elevated peak exposures to the point that the proposed PEL of 0.2 ug/m[3] is exceeded. In Section 12 -- Short-Term Exposures of Chapter IV of the Preliminary Economic Analysis of the Beryllium Proposed Standard, OSHA explains that having an exposure of 2.1 ug/m[3] for 30 minutes (note that the proposed short-term exposure limit [STEL] is 2.0 ug/m[3]) -- assuming no exposure for the remainder of the work shift -- results in an 8-hour TWA exposure of 0.13 ug/m[3]. In light of this information, OSHA believes that the exposure profile for material preparation, although limited, reveals that  peak exposures during maintenance of the spray chamber are driving the 8-hr TWA to levels at or above the proposed PEL.
Recent modifications to the maintenance process may result in lower exposures; however, OSHA does not have the information needed to quantify the extent of the reduction. As such, respiratory protection may be necessary for servicing and maintenance of the spray chamber.
Material Preparation Operators--Conclusion
Based on the information presented in the additional controls section, OSHA preliminarily concludes that exposures resulting from material transfer, loading, and spray drying can be reduced to below 0.1 ug/m[3] with process enclosures, ventilation hoods, and diligent housekeeping.  Accordingly, OSHA also preliminarily concludes that the proposed PEL of 0.2 ug/m[3] can be achieved most of the time for the majority of material preparation operators performing these tasks.
For maintenance of the spray chamber, however, OSHA's evidence indicates that peak exposures during these tasks result in 8-hour TWA exposures greater than 0.2 ug/m[3] most of the time. The Site 10 facility has reportedly modified this process to reduce worker exposures, but OSHA has no data to quantify this reduction. OSHA is requesting additional information that demonstrates the extent of the exposure reduction associated with modifications made to the spray-drying process.
Accordingly, OSHA is less certain that the proposed PEL of 0.2 ug/m[3] (or an alternative PEL of 0.1 ug/m[3]) can be achieved on shifts when all of material preparation activities are performed, i.e., material transfer, loading, spray drying, and maintenance of the spray chamber. On shifts when TWA exposures exceed 0.2 ug/m[3] despite the implementation of all feasible engineering controls, employees will need to wear respiratory protection during high exposure tasks, such as maintenance of the spray chamber.  For workers whose exposures are below the current PEL of 2.0 ug/m[3], a respirator with an assigned protection factor (APF) of 10 will be sufficient. These respirators (e.g., half-facepiece respirators) offer protection up to an exposure level of 2.0 ug/m[3]. For more elevated exposures, above 2.0 ug/m[3], a respirator that offers a minimum APF of 50 is necessary. Such respirators (e.g., full-facepiece respirators) provide protection against airborne beryllium concentrations of up to10 ug/m[3].
Forming Operators
This job category includes the forming operators who control pressing (dry and isopressing) and extrusion workstations. The initial paragraphs address forming operators who perform dry pressing. For the technological feasibility analysis on forming operators who work with extrusion equipment, refer to subsequent paragraphs on forming operators grouped as extrusion operators, also within this subsection on forming operators.
Forming Operators--Press Operators (Dry Pressing)--Baseline Controls
Workers can be exposed when they load and connect beryllium oxide ceramic powder containers to the press, load the die with ceramic powder, press the parts, remove the parts from the press, and unload and disconnect empty powder product-feed containers. Exposures can also occur during cleaning, servicing, and maintenance tasks on associated equipment. The sources of exposure are similar for the various kinds of press operations discussed below.
At Site 10, small presses have been enclosed with Plexiglas and ventilated since the late 1990s. To achieve low exposures in its dry-pressing operations, the facility employs low-volume high-velocity (LVHV) LEV pickups at the die press point of operation (vacuum hood is within inches of the die press), and it has fully enclosed and ventilated the small-press operations. Since 1999, the facility also has had full enclosures with LEV at the beryllium oxide powder-feed connections to presses. The powder transfer from the feed container to the press die is isolated within the machine-piping system and enclosures. Further, the facility has two LEV systems around the small presses: one capturing air through the operating envelope (this includes the die/ram press area, the area to which the parts are ejected, and the area of the hood into which the operator reaches to retrieve parts) and an LVHV central vacuum system for close capture of beryllium oxide particles from the newly pressed parts before the parts are removed from the ventilated enclosure. The small-press enclosures are custom-designed by outside vendors to accommodate press wiring and the mode of operation.
The two large presses at Site 10 are not enclosed but do have an LVHV vacuum pickup attached to the ram and positioned within inches of the die. This system provides close capture of powder that is released when the ram comes down into the die. The large presses also have ventilated devices called de-dusters that operators use to remove loose particles from pressed parts. A de-duster is a small, rectangular box under negative pressure with a series of holes on the top through which exhaust air is pulled. Workers manually swipe their parts over the top of the de-duster to remove loose particles after pressing. The exhaust ventilation is provided through a small, flexible exhaust duct connected to the side of the de-duster. Workers periodically disconnect the exhaust duct from the de-duster and use it to vacuum up loose material on the press.
The isopress operation is located in a separate room. The powder-filling station for this operation is partially enclosed with Plexiglas and ventilated. The operator works with his hands inside the enclosure and uses an open-face exhaust duct for cleaning. Some powder leakage occurs within the enclosure when molds are filled.
The facility has also attempted to optimize work procedures for exposure control. For example, when press operators must clean out the die area to prevent accumulations of powder, operators use wet methods to rehydrate materials and limit exposures during cleanup. Additionally, as an alternative to vacuuming, parts are sometimes wet-cleaned (e.g., with water and sponges) after each potentially dusty processing step (including pressing).
At Site 3, dry pressing is conducted inside a partial enclosure (open in the front) under LEV. In addition to performing dry pressing, the dry-press operator operates a dry abrasive cut-off saw for a separate line of parts. The saw is positioned inside a separate, partially enclosed and ventilated hood with an LEV pickup (plain opening exhaust duct) positioned close to the point of operation. Parts are removed from a holding tray and placed in position to be cut. The operator then cycles the semi-automated machine to perform the cutting action and loads the parts onto another storage tray in preparation for firing. The operator frequently uses a wet sponge to clean potentially contaminated surfaces, hands, and skin before removing anything from the enclosure. During the site visit, ERG investigators observed the dry-press operator wash his hands at least 16 times during the shift.
The isopress operator at Site 3 places prepared ceramic powder in a liquid-tight rubber mold inside a partially enclosed LEV hood (open in the front). The laboratory-type hood is about 10 feet long and has running water and both back- and downdraft exhaust flow. Molds that are removed from the isopress are positioned back inside the hood and disassembled, and then the parts are cleaned and stored in a covered container. The operator was observed using meticulous work practices to carefully clean all potentially contaminated surfaces with running water, a sponge, and a small bristled brush prior to removal from the hood. The worker traversed the entire length of the hood and was careful not to remove her contaminated hands prior to cleaning them.
Forming Operators--Press Operators (Dry Pressing)--Additional Controls
Table IV-19 shows that press operators have a median exposure level of 0.18 ug/m[3] and a mean of 0.48 ug/m[3]. As shown in Table IV-21 of Beryllium Oxide Ceramics and Composites Appendix 1, the median exposure levels for small-press and large-press operators are 0.18 ug/m[3] and 0.2 ug/m[3], respectively. The exposure profile also includes three full-shift PBZ sample results for "press setup" that are characterized by a median of 0.2 ug/m[3]. The isopress median exposure level is significantly higher at 0.83 ug/m[3]. Six of the seven isopress sample results were taken at Site 10 in 1995, however, and it is likely that exposures are lower now due to process, work practice, and migration control enhancements. The remaining isopress sample was collected on the isopress operator at Site 3 in 2003 and was nondetectable (below 0.06 g/m[3]) with the exposure controls in place at that facility (described above in the discussion of Baseline Controls).
The exposure profiles for small- and large-press operators are based primarily on 305 full-shift PBZ samples obtained over 10 years (1994 to 2003) at Site 10. This facility has reportedly made engineering, work practice, and beryllium migration control improvements over time. More recent efforts have been focused on refining work practices. In 2003, the median exposure levels for small-press (0.082 ug/m[3]) and large-press operators (0.04 ug/m[3]) were both less than 0.1 ug/m[3], although the number of sample results for large-press operators is limited (i.e., three sample results in 2003). Additionally, plant personnel report that exposures for small- and large-press operators in 2004 have generally been below 0.1 ug/m[3], although one recent observation was 0.24 ug/m[3] (Frigon, 2004). Based on this information, it seems likely that the exposure profile overestimates the current baseline exposure level for small- and large-press operators, and that 0.1 ug/m[3] may be a better estimate of the baseline exposure level for these workers. If indeed the current baseline exposure level is 0.1 ug/m[3], no additional controls would be required.
However, if the exposure profile accurately reflects current exposures, additional exposure reductions might be possible with improved work practices and machine interlocks to prevent workers from opening enclosures too soon or too rapidly after the operating cycle ends. For example, Brush Wellman personnel have noted that to avoid excessive turbulence, forming operators should be instructed not to open enclosures too soon after the operating cycle ends or too rapidly. If the enclosure is opened quickly, the vacuum created can overcome the ventilation inside the containment and release particles toward the worker (Frigon, 2004). Machine interlocks to prevent premature opening of the forming press enclosures would also help limit worker exposures. In a general sense, one industry expert suggests that combined engineering (e.g., machine interlocks) and work-practice improvements (e.g., opening enclosures carefully) typically reduce worker exposures by two to three times at beryllium oxide facilities (Kent, 2005).
Forming Operators--Press Operators--Conclusion
Table IV-22 of Beryllium Oxide Ceramics and Composites Appendix 1 shows that most exposures in small-press (57 percent), large-press (52 percent), and press setup (67 percent) operations are already less than or equal to the proposed 0.2 ug/m[3] PEL. In 2003 and 2004, one beryllium powder-forming facility reported that exposures for small- and large-press operators were generally below 0.1 ug/m[3]. For those few exposures that exceed the proposed 0.2 ug/m[3] PEL, interlocks on enclosure doors and improved work practices could help to reduce exposures. The isopress operation sample results are higher at Site 10, with 72 percent of exposures greater than the proposed 0.2 ug/m[3] PEL. The primary control method at this plant was a ventilated Plexiglas enclosure at the powder-filling station. Installing a more complete enclosure for the entire isopress operation, as was implemented at Site 3, would reduce exposures substantially, in that the ventilated enclosure used at Site 3 resulted in exposures below 0.06 ug/m[3] (ERG Beryllium Site 3, 2003). Based on these results, OSHA preliminarily concludes that exposures less than or equal to the proposed 0.2 ug/m[3] PEL and an alternative PEL of 0.1 ug/m[3] can be achieved in most press operations most of the time.
Forming Operators -- Extrusion Operators -- Baseline Controls
Opportunities for exposure tend to be lower when forming beryllium oxide ceramics using an extrusion process rather than pressing. During the extrusion process, beryllium oxide powder is mixed with binders to produce a paste. Water is added to the paste, which is then extruded to form the dimensions of the product. At Site 10, the operator manually removes the still-damp flexible product from the press as it is being extruded, lays it on a table, breaks off the excess by hand, and drops the excess into a bucket (ERG Beryllium Site 10, 2006). Extruded parts are then transferred to other workstations for subsequent processing. The paste has moisture content that helps reduce the potential for airborne particulate generation during this operation.
Because of the binders incorporated into the material, however, workers may encounter dried clumps of beryllium oxide ceramic material when cleaning out the extruders. To help prevent dust generation during cleanout, workers rehydrate materials by spraying them with water and use wet methods for cleanup. LEV is installed on top of the extrusion machine where the powder flows into the machine.
Forming Operators -- Extrusion Operators -- Additional Controls
As shown in Table IV-21 of Beryllium Oxide Ceramics and Composites Appendix 1, the median exposure level (exposure profile) for extrusion operators is 0.17 ug/m[3]. Table IV-22 of Beryllium Oxide Ceramics and Composites Appendix 1 indicates that 26 percent of the full-shift PBZ total beryllium sample results for extrusion operators are less than 0.1 ug/m[3] and 62 percent of exposures are less than or equal to the proposed 0.2 ug/m[3] PEL. These results are based on exposure data obtained from1996 to 2003 for extrusion operators.
Exposures during the extrusion operation are likely to occur during three processes: mixing of beryllium oxide powder with water and binders, the extrusion tooling operation, and machine cleaning. Control measures are available for each of these processes, although no data are available on the relative contribution of these processes to the overall worker exposure level. Additional ventilation of and enclosures for the powder-mixing operations would reduce fugitive emissions that contribute to exposures. For example, enhancing the existing ventilation or adding an additional exhaust hood at the tooling point of operation would serve to reduce exposures. Exposures might also be reduced through more frequent machine cleaning, more consistent wetting of dried ceramic residue, and/or the use of HEPA filter vacuums.
Forming Operators -- Extrusion Operators--Conclusion
The exposure profile for the extrusion operations indicates that 62 percent of exposures are less than or equal to the proposed 0.2 ug/m[3] PEL. In addition, control measures for the most significant sources of exposure are available. Thus, OSHA concludes that exposures less than or equal to the proposed 0.2 ug/m[3] PEL can be achieved for the majority of extrusion operations most of the time. Whether these controls will reduce exposures to or below 0.1ug/m[3] is less certain, and the agency requests additional information that demonstrates that exposures can be reduced to that level most of the time.
Kiln Operators
Kiln Operators--Baseline Controls
Kiln operations occur at the two production facilities that fire "green" beryllium oxide powder and at downstream facilities that metallize ceramic materials and subsequently perform a second firing of the parts. As noted in the Brush Ceramic Products' Material Safety Data Sheet for beryllia ceramics, volatile beryllium hydroxide can be formed when solid beryllium oxide parts are fired at temperatures exceeding 900°C in a moist atmosphere, such as in a hydrogen atmosphere sintering furnace (Brush Ceramic Products, 2006). This process results in beryllium oxide exposure in kiln operations.
Site 10 sinters green ceramic parts in air atmosphere tunnel kilns or in batch kilns. In the press room, smaller batch kilns and a tunnel kiln are used to evaluate samples for product specifications. Tunnel kilns are also used to clean parts before shipping and to fire parts that have been metallized. Green parts are fired in air (i.e., the composition of kiln air is the same as work environment air), whereas metallized parts are typically fired in an inert or reducing atmosphere (e.g., hydrogen and nitrogen). Kilns are vented to the external environment (outside the workplace) without any special HEPA filtration. Batch kilns used for production operations have tapered slot hoods suspended above the length of the kiln doors to capture heat and odors associated with the firing process (ERG Beryllium Site 10, 2006).
Central and portable HEPA filter vacuums are available for housekeeping purposes. Portable HEPA filter vacuums may be common in downstream facilities. Other specialized cleaning practices may not be as widely used among downstream users of beryllium oxide ceramics. Managers at Site 10 describe using additional controls, such as central vacuums, wet-cleaning stations designed to reduce the redistribution of contaminated water, and a disciplined approach to cleaning work areas (e.g., twice per shift shutdown of operations for cleaning). Workplace contamination in the kiln areas can occur when ceramic parts break and/or saggers are not kept clean (ERG Beryllium Site 10, 2006).
Kiln Operators--Additional Controls
Table IV-19 (exposure profile) shows that the median exposure level for kiln operators is 0.25 ug/m[3]. These results are based on three full-shift PBZ samples obtained in 1995 for kiln operators at Site 10. As shown in Table IV-20, all three sample results exceed 0.2 ug/m[3]. In addition, the OSHA beryllium docket contains summary statistics for six full-shift PBZ sample results for kiln operators at a beryllium oxide ceramic production and processing facility (OSHA-H005C-2006-0870-0094). These data are characterized by a mean of 0.31 ug/m[3] and range from 0.22 ug/m[3] to 0.57 ug/m[3]. The median was not provided and cannot be determined because individual values were not reported.
More recent information suggests that current exposures for kiln operators are generally below 0.1 ug/m[3] (0.04 ug/m[3], 0.04 ug/m[3], 0.04 ug/m[3], 0.08 ug/m[3] [median = 0.04 ug/m[3]; mean = 0.05 ug/m[3]]) (Frigon, 2005). This improvement might be attributable to changes in operations that reduced the amount of time kiln operators spend in the immediate vicinity of the kilns and/or the discontinuation of a nearby dust-generating operation (tape casting) (Frigon, 2004, 2005). These data suggest that the median exposure level in the exposure profile for kiln operators might overestimate the baseline exposure level for this job category. Thus, the baseline exposure level for kiln operators is estimated to be below 0.25 ug/m[3].
Re-engineering the furnace operations to reduce beryllium emissions would be impeded to some degree by the lack of knowledge about the exact source or cause of beryllium emissions in these areas. While the moisture content of the materials fired apparently contributes to emissions, the exact chemical form of the emissions has not been documented, and there is some uncertainty as to what steps might be effective. Also, exposures might occur when the furnace doors are opened to remove products or during the firing process. If exposure occurs when the furnace doors are opened, LEV improvements to the area in front of the kiln might be effective. If beryllium particles become airborne during kiln firing, additional ventilation controls might be needed at the furnace leakage points. The kiln modifications will require an engineering study to avoid problematic impacts on the airflow around the kiln. Given the median (baseline) exposure level of 0.25 ug/m[3], any reduction greater than 20 percent would be sufficient to meet the proposed 0.2 ug/m3 PEL. Improvements to the LEV could reduce exposures by approximately 20 to 50 percent (Kent, 2005).
In addition, contaminated saggers may be a source of exposure, and providing a HEPA-filtered vacuum to clean them would reduce exposures from this source.
Kiln Operators--Conclusion
The exposure profile for kiln operators is based on the results of three full-shift PBZ sample results obtained in 1995. The baseline exposure level for this job category is estimated to be less than the median exposure level of 0.25 ug/m[3]. More recent data from Site 10 suggest that kiln operator exposures have already been controlled to levels below 0.1 ug/m[3] (ERG Beryllium Site 10, 2006). If necessary, operator exposures could be reduced through enhanced LEV systems for the kilns and HEPA-filtered vacuums for cleaning contaminated saggers. Based on these data, OSHA concludes that exposures less than or equal to the proposed 0.2 ug/m3 can be achieved in the majority of kiln operations most of the time. Based on the more recent data from Frigon (Frigon, 2005), OSHA concludes that exposures below 0.1 ug/m[3] can also be achieved.
Machining Operators
Machining Operators--Baseline Controls
The engineering controls for machining operations at Site 3 and Site 10 are summarized below. These establishments have similar approaches to controlling exposures and OSHA found these controls to be associated with baseline practices: information from other establishments suggests that similar types of LEV (e.g., LVHV) and/or ventilated enclosures are widely employed (Facility B-1, 2000; Facility L-1, 2000; ERG Beryllium Site 3, 2003; ERG Beryllium Site 10, 2006). In addition to enclosures and ventilation systems, both beryllium oxide ceramic manufacturing facilities have established housekeeping programs to minimize and control workplace contamination (ERG Beryllium Site 3, 2003; ERG Beryllium Site 10, 2006).
Site 10 performs both wet and dry machining. Wet machining can be performed on hardened products that have already been fired in the kiln. Dry machining must be performed on non-fired (green) ceramic materials because wet machining would allow the material to absorb too much moisture. Dry machining is generally performed by positioning LVHV ducts as close to the point of operation as possible. Some hoods are close-fitting, custom-made hoods; others are plain-opening hoods. Control is achieved by positioning the hood and exhausting the air directly from the point of operation (where dust is generated). Capture velocities are very high, and small-diameter (e.g., 1 to 1.5 inches) flexible exhaust tubing must be positioned as close as possible (e.g., within 1 inch) to the point of operation. LVHV hoods are generally designed to have greater than 10,000 feet per minute (fpm) face velocities and configured such that they can be positioned within 1 inch of the source of generation. Capture velocity drops off dramatically with increased distance from the source. This means workers must carefully position LVHV hoods, because improperly locating a hood by just a small distance (e.g., by a few centimeters) can have a profound effect on the capture efficiency of the exhaust system (ERG Beryllium Site 10, 2006).
Wet machining is performed on fired ceramic materials and is typically performed inside exhausted enclosures equipped with sliding doors. Machining fluids/coolants are cleaned by one centralized filtration system to reduce the accumulation of beryllium oxide particulate, and the fluid/coolant reservoirs are also enclosed and under LEV.
Lapping and plate polishing are among the more difficult exposure control challenges for machining operators.  Site 10 performs lapping and polishing wet with no LEV or enclosures (ERG Beryllium Site 10, 2006). Operators wear gloves, rubber boots, full-body disposable coveralls (Saranex(TM)), and disposable Tyvek(R) sleeves. Impervious aprons are also worn when the potential for contact with machining solution exists.
Lapping is a wet and inherently sloppy operation and was originally performed with a water-based lapping fluid (i.e., grinding media mixed with a water-based carrying fluid). Polishing can also be performed with a fluid. To help lower airborne exposures associated with workplace contamination, Site 10 currently uses an oil-based lapping fluid. The oil-based fluid provides a "wet method" for reducing emissions from the machine but creates substantial housekeeping concerns. Oil- or water-based lapping fluids can be used, but both become infused with beryllium particles that are then sprayed around the machine as a result of the mechanical energy from grinding. Additionally, the water-based fluid can evaporate and leave a beryllium-containing dust that can become airborne. The oil system dries more slowly, decreasing the rate at which beryllium particulate might dry and become airborne. Although Site 10 currently uses oil-based fluids, (Frigon, 2005) noted that other facilities often still use water-based lubricating systems (Frigon, 2005).
Due to the potential for workplace contamination, Site 10 isolated lapping and polishing activities in a dedicated work suite, thereby lowering exposures in nearby operations (e.g., extruding) (ERG Beryllium Site 10, 2006). Although some establishments have isolated lapping operations, others have kept these operations out on the production floor. For example, at one production machine shop ERG visited (Site 9), the lapping machine sat amidst other machining operations. The lapping machine was observed to be enclosed and ventilated, however. This facility was a general metallic beryllium machining operation, not one specific to beryllium oxide machining (ERG Beryllium Site 9, 2004).
Specific work practices also vary with wet or dry machining. The machining operator running the dry-machining center vacuums finished parts before placing them in the storage container. After machining parts using wet methods, the operator wiped them dry before placing them in the storage container.
Site 3 makes extensive use of full-machine enclosures. There are approximately 60 beryllium oxide machining centers at Site 3, and each is fitted with LEV and fully enclosed with a stainless steel frame and Plexiglas enclosure. At the time of the site visit, the machining operator was observed running a surface grinder under a flood of coolant (in a fully enclosed and ventilated machining center). After completing the machining cycle (approximately three minutes), the worker removed the part, rinsed it in a tray of water, wiped it off with a sponge, and placed it in a part tray (ERG Beryllium Site 3, 2003).
Machining enclosures and LEV hoods throughout the facility are served by 12 LVHV exhaust ventilation systems connected to HEPA filter dust collection units. Eight are rated at 3,000 cubic feet per minute (cfm) and four are rated at 2,000 cfm. There is also one LVHV HEPA filter collection system dedicated to the machining department. Machine controls are reportedly linked to the operation of the ventilation system, and critical alarms are installed to indicate system malfunction. Differential pressure gauges across the filters are installed, checked, and routinely recorded. Internal personnel service and maintain the ventilation system on an annual basis (ERG Beryllium Site 3, 2003).
Machining Operators--Additional Controls
As shown in Table IV-21 of Beryllium Oxide Ceramics and Composites Appendix 1, the exposure profile for machining operators includes sample data for a variety of machining tasks and is characterized by an overall range of 0.01 ug/m3 to 5.0 ug/m[3], a mean of 0.32 ug/m[3], and a median of 0.15 ug/m[3]. Seven of nine machining operations have low exposures:
Ignition module machining (71 percent of exposures are less than or equal to 0.2 ug/m[3])
Surface grinding (100 percent of exposures are less than or equal to 0.2 ug/m[3])
Laser scribing (81 percent of exposures are less than or equal to 0.2 ug/m[3])
Complex (precision) machining (76 percent of exposures are less than or equal to 0.2 ug/m[3])
Drilling (100 percent of exposures are less than or equal to 0.2 ug/m[3])
Machining resister cores (67 percent of exposures are less than or equal to 0.2 ug/m[3])
Dry (green) machining (69 percent of exposures are less than or equal to 0.2 ug/m[3])
Drilling, machining resistor cores, and dicing all have median exposure levels that exceed 0.1 ug/m[3]. The number of full-shift PBZ sample results for each of these machining activities is quite limited (i.e., one to three samples each), and in all cases, these data represent samples obtained more than 10 years ago. Note that both lapping and plate polishing and dry (green) machining also have median exposures above 0.1 ug/m[3]; however, many more samples are available for these operations (60 and 180 samples, respectively).
Given the reported improvements in exposure control at this facility over time, the baseline exposure levels for drilling, machining resistor cores, and dicing would likely be lower than the exposure profile indicates. In those circumstances where exposures in the above-listed operations exceed the proposed 0.2 ug/m3 PEL, additional controls would include ensuring that existing control measures are working properly and that proper procedures are being followed.
Green machining (primarily laser bores) and lapping and plate polishing comprise the bulk of the machining sample results for which additional controls are required. The exposure profiles for these operations are based on 240 full-shift PBZ samples obtained over a 10-year period (1994 to 2003) at Site 10. The median exposure levels (exposure profile) for green machining and lapping and polishing are 0.16 ug/m[3] and 0.29 ug/m[3], respectively. Site 10 has reported improvements in exposure controls over time. Exposure control improvements include isolating lapping and polishing from the rest of production in two separate, enclosed areas; switching to an oil-based lapping abrasive; revising personal protective equipment (PPE) requirements; adding additional air-conditioning capacity to lapping areas to address PPE heat stress issues; covering machine coolant containers; filtering machining fluid and lapping abrasives to remove beryllium particulate; and addressing work practice issues (Frigon, 2005). Data showing to what extent exposures have been reduced are not available. Nonetheless, since the median exposures for green machining are already below the proposed 0.2 ug/m3 PEL, and the median exposures for lapping and polishing are only slightly above the proposed 0.2 ug/m3 PEL, only modest reductions were needed. It seems likely that the controls that have been implemented are sufficient to reduce exposures in these operations most of the time.
Where machining operator exposures continue to exceed 0.2 ug/m[3], additional controls will be needed. Physical enclosures around lapping equipment might be helpful for further limiting the migration of lapping fluid. The barriers would help prevent lapping fluid from escaping from the equipment and splashing onto worker clothing, equipment, and work surfaces in close proximity. This additional control also would limit the amount of workplace and worker contamination and reduce exposures associated with the contamination. As noted in the section on Machining Operators -- Baseline Controls, during a visit to a beryllium machine shop (Site 9), investigators observed that a double-sided lapper used for production machining was enclosed and ventilated. Exposures associated with lapping and other wet-machining operations might also be reduced by adding enclosures and/or LEV at points of fluid agitation or effervescing that are not already contained and ventilated.
Machining Operators--Conclusion
In general, exposure during machining operations is low. Overall, 63 percent of exposures in these operations are less than or equal to the proposed 0.2 ug/m3 PEL. For most operations, ensuring that existing controls are working properly and that appropriate procedures are followed consistently will address the few exposures that exceed the proposed 0.2 ug/m3 PEL. Additional controls for the lapping and polishing operations have been installed at Site 10 and are believed to be effective in reducing exposures. In addition, enclosing the lapping operations to reduce the migration of contaminated fluids will reduce the level of beryllium contamination and thus, reduce worker exposures. Because only modest reductions are needed to achieve exposures at or below the proposed 0.2 ug/m3 PEL, OSHA preliminarily concludes that exposures at or below the proposed 0.2 ug/m3 PEL can be achieved in the majority of machining operations most of the time. Sixty-three percent of the exposures in machining operations are greater than or equal to 0.1 ug/m[3]. 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 practices would be challenging. Therefore, the Agency requests additional information, including exposure data and effectiveness of controls, to make a determination on the feasibility of an alternative PEL of 0.1 ug/m[3].
Metallization Workers
Metallization Workers -- Baseline Controls
Metallization workers operate the metallizing equipment and then transfer parts to a kiln for firing (or re-firing). While metallizing operations do not generate beryllium dust, the firing process can generate beryllium-containing emissions.
Metallizing typically occurs within an enclosed chamber and involves coating all or part of the ceramic with a molybdenum-manganese material by roll-coating, spraying, or screen printing. Thus, dust generation is not normally an issue. After metallization, parts are nickel-plated and fired (sintered) at high temperatures in a furnace with a reducing atmosphere. Worker exposure can occur if the furnace lacks sufficient ventilation.
Metallization Workers -- Additional Controls and Conclusion
As shown in Table IV-19, the median exposure level for metallization workers is 0.06 ug/m[3]. Table IV-20 shows that 69 percent of exposures during metallizing activities are less than or equal to the proposed 0.2 ug/m3 PEL, and 55 percent of exposures are less than 0.1 ug/m[3], based on 36 full-shift PBZ sample results obtained at Site 10 from 1996 to 2003. In those infrequent instances when exposures exceed these levels, OSHA believes that ensuring that existing controls are working as intended, that proper work procedures are followed, and that housekeeping is maintained will reduce exposures. Based on these data, OSHA preliminarily concludes that exposures less than or equal to the proposed 0.2 ug/m3 PEL can be achieved in the majority of metallizing operations most of the time, and that exposures less than 0.1 ug/m[3] can also be achieved most of the time.
Production Support Workers
Production Support Workers--Baseline Controls
This job category primarily includes packaging and maintenance workers. At Site 10, packaging is conducted in one room in a nonproduction area of the facility. Packaging operators receive cleaned and finished parts from the production area through a "pass-through" airlock. They perform visual/dimensional inspections and packaging of parts under laboratory-type LEV hoods.
Maintenance work includes building and grounds maintenance as well as production maintenance. At Site 10, workers conduct maintenance work on uncontaminated equipment and parts in a central maintenance shop. For production-related work, two smaller satellite maintenance shops are available in production areas of the plant (wastewater treatment and material preparation). Maintenance workers must follow facility policies and procedures when working in production (regulated) areas. These procedures include using PPE (e.g., work clothing, disposable coveralls, gloves, shoes and socks, shoe covers, loose-fitting powered air-purifying respirators) and following personal hygiene requirements (e.g., strict handwashing, taking showers after exiting production areas). Maintenance workers and other production support workers, such as janitors, have wet-cleaning methods and HEPA-filter vacuums (central and portable) available for housekeeping and equipment decontamination.
Production Support Workers--Additional Controls and Conclusion
As shown in Table IV-19, the median exposure level for production support workers is 0.05 ug/m[3]. Table IV-20 shows that 88 percent of production support workers' exposures are less than or equal to the proposed 0.2 ug/m3 PEL, and 68 percent of exposures are less than 0.1 ug/m[3], based on 119 full-shift PBZ sample results obtained at Site 10 from 1996 to 2003. OSHA believes that the infrequent exposures above 0.2 ug/m[3] are a result of maintenance activities that occur in the production areas, and that production support workers' exposures will be reduced as the general level of contamination decreases in the course of lowering other workers' exposures. Thus, no additional controls will be needed specifically for production support workers. Based on these data, OSHA preliminarily concludes that exposures less than or equal to the proposed 0.2 ug/m3 PEL can be achieved in the majority of production support operations most of the time, and that exposures below 0.1 ug/m[3] also can be achieved in these operations most of the time.
For some unusual maintenance activities, the varied work requirements make finding an effective control problematic. For these tasks, maintenance workers will need to continue using appropriate PPE, including respiratory protection. For workers whose exposures are below the current PEL of 2.0 ug/m[3], a respirator with an assigned protection factor (APF) of 10 will be sufficient. These respirators (e.g., half-facepiece respirators) offer protection up to an exposure level of 2 ug/m[3]. For situations that can create more elevated exposures (e.g., upset conditions, such as a spill of beryllium oxide-containing material), a respirator that offers a minimum APF of 50 is necessary. Such respirators (e.g., full-facepiece respirators) provide protection against airborne beryllium concentrations of up to 10 ug/m[3]. Thus, for example, if the PEL is set at the proposed level of 0.2 ug/m[3], a production support worker with an exposure of 7.70 ug/m[3] (the highest exposure level in OSHA's exposure profile for this job category) would require a respirator with an APF of 50. A tight-fitting powered air purifying respirator (PAPR) (with an APF of 1,000) would also be acceptable.
Administrative Staff--Technological Feasibility
Administrative Staff--Baseline Controls
At Site 10, administrative workers are no longer allowed to freely enter production areas. Access to production work areas requires compliance with facility policies and procedures, including using PPE (clothing and loose-fitting powered air-purifying respirators) and personal hygiene practices (handwashing and showers). Site 10 has designated zones of control: administrative zone, production zones, and interplant lab/office/break area zones. Transition zones separate production zones from interplant office/break zones. The transition zones are equipped with sticky floor mats, HEPA-filtered air showers, and facilities for donning/doffing a second set of gloves and shoe covers. Where appropriate, material/product/ paper "pass-throughs" and inter-zone intercoms were installed to minimize worker traffic between production and interplant lab/office/break areas (ERG Beryllium Site 10, 2006).
For other establishments in the industry, migration control measures may not be as consistent. Site visit data for other sectors (e.g., beryllium production) also suggest that production and administrative areas might not be well separated. For example, at Site 3, the employer does relatively little to separate administrative workers from production areas. Administrative personnel enter the production areas of the facility in street clothes and shoes without any special precautions. Production workers are permitted in the office environment but enter only infrequently.
Administrative Staff--Additional Controls and Conclusion
As shown in Table IV-19, the median exposure level (exposure profile) for administrative workers is 0.05 ug/m[3]. Table IV-20 shows that 98 percent of administrative staff exposures are less than or equal to the proposed 0.2 ug/m3 PEL and 93 percent are less than 0.1 ug/m[3]. This finding is based on 185 full-shift PBZ sample results obtained for office, engineering, and R&D personnel from 1995 to 2003 at Site 10. The low exposures achieved in this plant are the result of reasonable approaches to limit access to potentially hazardous areas and to minimize the migration of contamination from the production areas of the plant. Other facilities should be able to achieve the same results with the same or similar measures. Therefore, OSHA preliminarily concludes that administrative staff exposures less than or equal to the proposed 0.2 ug/m3 PEL can be achieved in the majority of administrative operations most of the time, and that exposures less than 0.1 ug/m[3] can also be achieved most of the time.
Summary
OSHA identified seven beryllium oxide ceramics production job groups with beryllium exposure: material preparation operator, forming operator, machining operator, kiln operator, production support, metallization, and administrative work.  Four of these jobs (i.e. material preparation, forming operator, machining operator and kiln operator) work directly with beryllium oxides, and therefore these jobs have a higher potential for exposure.  The other three job groups (i.e. production support work, metallization, and administrative work) have primarily indirect exposure that occurs only when production support, metallization, and administrative workers enter production areas and are exposed to the same sources to which material preparation, forming, machining and kiln operators are directly exposed. However, some production support and metallization activities do require workers to handle beryllium directly, and these workers may therefore at times be directly exposed to beryllium.