The 2010 County Business Patterns reported 96 establishments engaged in copper rolling, drawing, and extruding with a total of 9,849 workers, for an average of 102.6 employees per establishment. Assuming that the 15 affected establishment in NAICS 331421: Copper Rolling, Drawing, and Extruding are typical of other establishments in this industry and have an average of 102.6 employees per establishment, the affected establishments have a total of 1,539 (15 x 102.6) employees.
      The 2010 County Business Patterns shows 114 establishments in NAICS 331422: Copper Wire (Except Mechanical) Drawing, employing 9,847 employees, for an average of 86 workers per establishment. With the same assumption for the 59 affected establishments from NAICS 331422: Copper Wire (Except Mechanical) Drawing, there are a total of 5,096 (59 x 86) employees in the affected establishments.  Table III-6 summarizes the estimates of the number of affected establishments and employees for this application group.  OSHA seeks comment and additional data on these estimates.

7. Fabrication of Beryllium Alloy Products
	Copper-beryllium alloys (less than or equal to 2 percent beryllium) are used to make a variety of products for electrical applications in this application group, which encompasses    four 6-digit NAICS codes:
      NAICS 332612: Light Gauge Springs Manufacturing;
      NAICS 332116: Metal Stamping;
      NAICS 334417: Electronic Connector Manufacturing; and
      NAICS 336322: Other Motor Vehicle Electrical and Electronic Equipment
           Manufacturing.
      Establishments producing electronic connectors or other stamped and formed metal products are classified in three NAICS industries.  Facilities specializing in the production of electronic connectors and components are classified in NAICS 334417: Electronic Connector Manufacturing or NAICS 332116: Metal Stamping (which produces a wider range of parts).    Manufacturers in NAICS 336322: Other Motor Vehicle Electrical and Electronic Equipment Manufacturing might also use copper-beryllium alloys in the assembly or production of electrical or electronic-related automotive parts.
      Manufacturers of stamped metal products (NAICS 332116) use a variety of metals, including copper-beryllium alloys, to produce products for a range of applications.  Based on information from industry representatives, copper-beryllium is used, at least occasionally, by most stampers that supply the electronics industry (see Chapter IV: Section 9 of this PEA).
       Large and medium-size stamping operations are primarily automated.  However, smaller shops may still use manually operated presses, and larger shops may maintain manually operated equipment for smaller jobs. According to industry representatives, connector manufacturers may either stamp copper-beryllium components in-house or purchase these components from a stamper, but virtually no grinding or other machining is performed on parts after stamping.   Connector assembly is also reported to be largely automated. If employees only assemble but do not manufacture copper-beryllium parts, their exposure is only from handling "articles" and should be negligible.  If the employees are not otherwise exposed to beryllium, their employers would not fall within the scope of the proposed standard.
Estimates of the Number of Affected Establishments
      NAICS 332612: Light-Gauge Springs Manufacturing

      Data from the 2010 County Business Patterns show that there are 323 establishments in NAICS 332612: Light Gauge Spring Manufacturing.  Of these establishments, most (93.3 percent) employ fewer than 100 employees.  Industry contacts suggested that, because no special equipment is needed to process copper-beryllium (as opposed to other alloys), almost any light gauge spring manufacturer (NAICS 332612) may use copper-beryllium from time to time.  All coil spring manufacturers contacted by ERG indicated that they use copper-beryllium.  Thus, ERG assumed that all light-gauge spring manufacturers are using beryllium even though they may use it only occasionally and in small amounts  (see Chapter IV: Section 9 of this PEA). ERG's industry contacts and spring manufacturers' websites indicated that most spring manufacturers use copper-beryllium alloys, but that copper-beryllium springs typically account for only a small percentage of sales.  This was reiterated by a representative of the Spring Manufacturers Institute (Wood, 2001).
      NAICS 332116: Metal Stamping
      According to the 2010 County Business Patterns, the metal stamping industry (NAICS 332116) is comprised of 1,484 establishments, with approximately one-half being small establishments having fewer than 20 employees.  Most of these metal stamping establishments do not manufacture products for the electronics industry (the only industry using metal stamping products that contain copper-beryllium alloy), so there would be no beryllium exposure in most of these establishments.  Based on data from the 2007 Economic Census Product Summary, it is possible to identify the subset of companies that are likely to be stamping copper-beryllium parts for the electronics industry. The four product codes listed below are the ones that OSHA has preliminarily determined comprise all copper-beryllium electronics applications in this NAICS industry code:
      NAICS<PHONE_NUMBER>: Radio and Phonographs;
      NAICS<PHONE_NUMBER>: Televisions;
      NAICS<PHONE_NUMBER>: Computers; and
      NAICS<PHONE_NUMBER>: Office Machines.
      The 2007 Economic Census reports a total of 97 companies in these product classes.  However, some companies likely produce in more than one of these product classes, and simply adding together the Census-reported manufacturers producing each product almost certainly overestimates the total number of these producers. Instead, based on the number of companies for these four product classes (97) and the average number of establishments per company for the stamping industry as a whole (1.05) (see Chapter IV: Section 9 of this PEA), ERG estimated that a total of 102 (97 x 1.05) establishments are operated by these companies.  This estimate was brought forward to an estimate for 2010 by multiplying this number by the ratio of total number of establishments in this NAICS in the 2010 CBP (1,484) to same number in the 2007 Economic Census (1,528), giving an estimate of 99 establishments in 2010 (102 X (1484/1528)).
      Based on discussions with industry representatives, OSHA concluded that approximately 75 percent of metal stamping establishments producing parts for the electronics industry work with copper-beryllium alloys.  Table III-7 at the end of this section shows the estimated number of 74 establishments (75 percent of 99 establishments) in the metal stamping industry that use copper-beryllium alloys.  OSHA has preliminarily determined that these estimates account for all establishments in the metal stamping industry where workers are at risk of beryllium exposures.
      NAICS 334417: Electronic Connector Manufacturing
      According to the 2010 County Business Patterns, electronic connector industries (NAICS 334417) comprise 231 establishments, with about one-half of these being small establishments having fewer than 20 employees.
      None of the industry sources ERG contacted could estimate the share of electronic connector manufacturers that use copper-beryllium, but, because of the cost of this alloy, most sources believe that the number of users in this sector is limited.  This assumption is supported by a review of information on connector manufacturers in the Thomas Register and on the Internet (Thomas Register, 2002; Thomas Net, 2006).  Based on these sources, OSHA preliminarily estimates that 20 percent of electronic connector manufacturers use copper-beryllium alloys.  Applying this percentage to the establishment figures from the 2010 County Business Patterns, the Agency estimates in Table III-7 that 46 establishments in this industry (231 x .20) use beryllium alloys.
      NAICS 336322: Other Motor Vehicle Electric and Electronic Equipment Manufacturing
      According to the 2010 County Business Patterns, 636 establishments produce automotive electrical and electronic equipment (NAICS 336322). This industry is dominated by small and mid-sized establishments.
      Data describing the number of automotive parts manufactured using beryllium alloys are not available.  Based on an earlier analysis of data from the 2002 Economic Census and the Materion customer database, ERG estimated that about 25 percent of automotive parts manufacturers perform stamping of beryllium alloys, primarily for electronic applications (see Chapter IV, Section 9).  Applying this percentage to the establishment and employment figures from the 2010 County Business Patterns, the Agency estimates that 159 establishments (636 x .25) in this industry use beryllium alloys.
Estimates of the Number of Affected Employees
      For all sectors, OSHA has assumed that the number of employees per establishment in affected establishments is the same as that for all establishments in their respective six-digit NAICS.   Table III-7 presents the Agency's estimates of the number of employees and affected employees in the stamping, spring, and connector manufacturing application group.  OSHA requests comment and additional data regarding these estimates.

8. Welding
      For the purposes of assessing beryllium exposure, welding operations can be divided into two broad categories: arc and gas welding, and resistance welding.   For both broad categories beryllium exposures are not common, and when observed are low (see Chapter IV: Section 10 of this PEA).
      a.  Arc and gas welding
      Beryllium exposures can occur in arc and gas welding operations when welding on base materials containing beryllium and when using equipment with electrodes that include beryllium (hereafter generally referred to simply as "welding"). Note "gas welding" in this context also uses electrodes; the gas used is to protect the weld from the atmosphere.
       The principal area of welding exposures is among workers welding beryllium or beryllium-alloy products.  The exposure profile in OSHA's technological feasibility analysis indicates that exposures do occur among these workers (see Chapter IV: Section 10 of this PEA).
          ERG used data from a 2001 Materion customer survey to estimate the number of employers engaged in welding beryllium or beryllium-alloy products (ERG, 2005; Kolanz, 2001).  In using these data, ERG assumed that Materion customers comprise essentially all domestic users of beryllium-containing materials.  While there is one other domestic and one international supplier of beryllium-containing materials, these firms have a much smaller presence in the market, and most of their customers also purchase supplies from Materion.
       Materion's customer survey reported that Materion customers employ roughly 2,000 workers who are engaged in welding -- 1,697 in strip customer facilities and 332 in bulk product customer facilities (Kolanz, 2001).  Using ERG's estimate that the average establishment employs 4 welders yields an estimate of 500 establishments that perform these operations.
      To distribute these 500 establishments among the appropriate NAICS industries, ERG used beryllium sampling data from OSHA's IMIS database to identify those SIC-classified industries where beryllium alloy welding is likely to be performed, and then mapped these SIC industry codes to NAICS industry codes (OSHA, 2009).  This procedure gives an estimate of the relevant number of establishments in these industries, but not every establishment in these industries performs such welding operations.
      The 2010 Occupational Employment Survey reported the share of establishments employing arc and gas welders in each industry.  ERG multiplied the corresponding share for welding occupations by the number of establishments in each selected industry (as reported by the 2010 County Business Patterns) to calculate the number of establishments in each industry where welding is estimated to be performed.  This procedure resulted in an estimate of a total of 17,317 welding establishments across all the relevant industries.
      Assuming establishments welding on beryllium alloys are evenly distributed across these industries, ERG multiplied the ratio of 500 beryllium-alloy welding establishments to 17,317 welding establishments overall (500/17,317 = 2.9%), by the number of welding establishments in each industry to generate the industry-specific estimates of the number of beryllium-alloy welding establishments.  These totals were then multiplied by 4 (estimated number of welders per establishment) to estimate the numbers of beryllium alloy welders in each industry.  Table III-8 presents the resulting beryllium-alloy welders and welding establishment estimates.
      a. Resistance welding
      In resistance welding, exposures may occur from beryllium in the base metal or in the electrodes of the welding equipment.   However, as discussed in greater detail in Chapter IV: Section 10 of this PEA, ERG's review of IMIS data found only very low exposures for resistance welders, suggesting most exposures well below the proposed PEL of 0.2. Nevertheless, in limited circumstances exposures above the Action Level of 0.1 may occur.
      Multiple sources indicate that copper-beryllium resistance welding electrodes might be used in any industry where spot, projection, or seam welding occurs; however, these types of electrodes are used primarily in three industries:  (1) the majority are used in NAICS 3363:  Motor Vehicle Parts Manufacturing Industry; with additional uses in (2) NAICS 333415: Air-Conditioning and Warm Air Heating Equipment, and Commercial and Industrial Refrigeration Equipment Manufacturing; and (3) NAICS 3352: Household Appliance Manufacturing (Burnett, 2001; Foley; 2001; Green, 2001; Mitchell, 2001; and Pelkey, 2001). One supplier estimates that these three industries account for approximately 90 percent of the market for copper-beryllium electrodes (Burnett, 2001). According to the American Welding Society, roughly half of welding machine operators might operate various types of resistance welding machines (Mitchell, 2001).  Based on discussions with industry contacts, ERG analysts consider that beryllium-affected industries are more likely to use resistance welding, versus gas or arc welding, and so estimate that 75 percent of welders are resistance welding machine operators in these industries. Data from the 2010 OES (BLS, 2010) show that between 5 and 7 percent of establishments in these industries, or about 400, employ a total of approximately 6,000 resistance welders.  These estimates for resistance welding are summarized in Table III-9.

9. Dental Laboratories
      Dental technicians and other dental workers may be exposed to beryllium, primarily while performing induction casting and finishing the metal framework for dental prosthetic devices -- specifically crowns, bridges, and cast partial dentures -- made from beryllium-containing metal alloys.  Beryllium is added to some dental alloys (typically in quantities of 0.5 to 2.0 percent) to improve strength, corrosion resistance, and elasticity; it is considered to be a less expensive alternative to silver and gold.  Crowns and bridges are typically made of metal, ceramic, or a blend of metal and ceramic materials. Metals used to make crowns and bridges are often divided into precious (gold, etc.) and non-precious alloys. Beryllium occurs only in dental prosthetics made with non-precious Nickel-Chromium-Beryllium (Ni-Cr-Be) alloys.
      These beryllium exposures occur in dental laboratories located in two types of establishments:  onsite laboratories that are part of a dental office, which are included in NAICS 621210: Offices of Dentists, and separate laboratories included in NAICS 339116: Dental Laboratories.
Estimates of the Number of Affected Dental Offices
      According to the 2010 County Business Patterns, there are 129,830 establishments in NAICS 621210: Offices of Dentists, which employ a total of 846,092 persons.  Beryllium exposure for these offices occurs in captive dental laboratories where technicians might be making dental appliances containing beryllium alloys.  OSHA is not aware of any published data regarding the number of dentists' offices that include captive dental laboratories, but a representative of the National Association of Dental Laboratories estimates that 950 dental practices include such laboratories (see Chapter IV: Section 11 of this PEA).
Estimated Number of Affected Dental Laboratories
      According to the 2010 County Business Patterns, there are 6,995 establishments in NAICS 339116: Dental Laboratories.  These establishments employ a total of 44,030 persons.  Most of the establishments are small: over 94 percent of them have fewer than 20 employees.
      While there appears to be some continuing use of beryllium in dental labs for dental implements in the United States, recently there seems to have been a significant shift away from the use of beryllium alloys and towards beryllium-free alternatives.  Paul Cascone -- Senior Vice President of Technology, Argen, Inc. (San Diego, California), and an expert on the market for suppliers of dental laboratory materials -- has reported on the market share of Ni-Cr-Be alloys over a period of ten years.  In 2004, he indicated that non-precious metals accounted for 50 percent of the market for dental materials used to make crowns and bridges, of which 90 percent contained beryllium.  In 2011 he reported that the non-precious metal share of the market had declined to 40 percent, where again 90 percent contained beryllium.  In 2012 and 2013, he noted that due to a continuing increase in the market share of ceramics, non-precious metals' market share had fallen to 30 percent, where the same 90 percent of that non-precious metals continued to be beryllium-containing alloys. In short, the share of dental implements using beryllium declined from 45 percent to roughly 25 percent over the nine-year period from 2004 to 2013.  Much of the shift to ceramics was driven by what is perceived as their superior aesthetics and that within the metal-based part of that market, numerous beryllium-free alternatives are increasingly used (ERG, 2013).  Based on ERG discussions with Mr. Cascone (Cascone, 2012 and 2013) and with other industry sources, OSHA estimates that 25 percent of the 6,995 dental laboratories (1,749) currently use beryllium alloy to some extent.  (Because current data and future trends are uncertain, OSHA will examine the effects of alternative levels of beryllium use in dental labs in its sensitivity analysis presented in Chapter VII of this PEA.)
      Due to the declining market-share for non-precious alloys, the increasing popularity of dental prosthetics made with ceramic materials, and the availability of beryllium-free alternatives, the Agency estimates that, after the promulgation of the proposed beryllium standard, 75 percent of the 1,749 (0.75 X 1,749 = 1,312) dental laboratories currently using a beryllium alloy will substitute a non-beryllium alloy due to the increased regulatory costs of working with beryllium, leaving 437 laboratories (1,749 - 1,312) with employees potentially exposed to beryllium in NAICS 339116: Dental Laboratories.
      Given the dynamic nature of this market, the Agency invites comment on the extent of beryllium use in the dental laboratories materials market and possible future trends in usage.  As well, the Agency solicits comment on possible changes to exposure levels for dental lab employees due to these movements (see also Section IX of the preamble.)   The Agency discusses specific details of the dental market in greater detail in Chapter V of this PEA.   Table III-8 shows the estimated number of dental labs and labs in dentists' offices.  OSHA invites comment on these estimates.
Estimates of the Number of Affected Employees
      Occupational employment data indicate that most employees in dental laboratories (NAICS 339116) are dental laboratory technicians (2010 OES).  According to the 2010 County Business Patterns, there are 6,995 establishments in NAICS  339116, Dental Laboratories (U.S. Census Bureau, 2010). These establishments employ a total of 44,030 workers. Occasionally, a dentist office (NAICS 621200, Offices of Dentists) may contain a captive dental laboratory that performs the activities of dental laboratories in NAICS 339116.  The 2010 County Business Patterns reports 129,830 establishments and 846,092 employees in NAICS 621200. While no data exist on the number of dentist offices that contain captive dental laboratories, a representative of the National Association of Dental Laboratories estimates that 950 dental practices include a captive dental laboratory (Napier, 2004). Assuming that these 950 dental practices employ the average number of workers per establishment in NAICS 621200, there are a total of 6,191 (846,092/129,830 x 950) employees in dental laboratories contained in dentist offices. Based on discussions with industry sources, OSHA estimates that approximately 25 percent of dental laboratories use beryllium alloys (Cascone, 2013; ADA, 2011). Thus, OSHA estimates 1,749 (0.25 x 6,995) affected establishments in NAICS 339116 and 238 (0.25 x 950) affected establishments in NAICS 621200 for a total of 1,986 affected establishments. Assuming that these establishments employ the average number of workers for their respective industries, OSHA estimates 11,008 (44,030/6,995 x 1,749) affected employees in NAICS 339116 and 1,548 (846,092/129,830 x 238) affected employees in NAICS 621200. Thus a total of 1,986 affected dental laboratories employ 12,555 (11,008 + 1,548) workers.  Table III-10 contains OSHA's estimate of the number of employees in dental labs, and those employed in dentist offices, who are estimated to currently work with beryllium alloys.  OSHA invites comments on these estimates.

      10. Other Industries
      There is anecdotal evidence that beryllium materials may be used in other industries and products, and hence there may be employers and employees affected by the proposed rule in those industries.  Beryllium use has been reported in jewelry, golf clubs, and bicycles, but OSHA has not been able to confirm that beryllium is currently used in the production of these items.  U.S. laboratory workers may have exposure to beryllium salts where Beryllium Lymphocyte Proliferation Tests (BeLPT) are processed (NJMRC, 2003). Employees in the private aerospace industry may have exposure to beryllium, but OSHA has not been able to confirm a report that non-military personnel perform work on aircraft using beryllium parts. The Agency has preliminarily concluded that it has captured elsewhere in this industry profile the machining and production of beryllium-containing airplane parts in NAICS 332721: Precision Turned Products Manufacturing.
      The Agency is aware that commercial laundries that wash uniforms of beryllium-exposed workers may have potential exposure.  OSHA has preliminarily judged that this does not present a likely health risk so long as such clothing is handled by commercial laundries experienced in working with clothing contaminated with hazardous materials.  In practice, these types of commercial laundries are almost exclusively providers of such services. OSHA currently has no evidence of exposures to workers in these types of establishments and no evidence of any improper handling.  The proposed rule would require "laundering, cleaning, ... at an appropriate location or facility away from the workplace," meaning that the laundering service must already be equipped to handle hazardous materials without exposing their employees (see Section (h)(2)(iv) of the proposed rule).
      The Agency seeks comment on these and any other affected industries. The Agency expects that any newly identified industries are likely to have incidental or very low exposures relative to the proposed PEL.  Thus, OSHA anticipates that any additional industries would have costs and economic impacts similar to low-exposure industries described above, such as metal stampers, where there are only some costs for ancillary provisions (and no costs for engineering controls).
Summary of Affected Establishments and Employers
      As shown in Table III-11, OSHA estimates that a total of 35,051 workers in 4,088 establishments will be affected by the proposed beryllium standard.  Also shown are the estimated annual revenues for these entities.  Table III-12 presents similar information for small entities, as defined by the Small Business Administration (SBA), estimated to be affected by the proposal.   Table III-13 presents the same information for the subset of small entities with fewer than 20 employees.
Beryllium Exposure Profile Of At-Risk Workers
      The technological feasibility analyses presented in Chapter IV of this PEA contain data and discussion of worker exposures to beryllium throughout industry, and the exposure profiles presented here were taken directly from that chapter.   Exposure profiles, by job category, were developed from individual exposure measurements that were judged to be substantive and to contain sufficient accompanying description to allow interpretation of the circumstance of each measurement.  The resulting exposure profiles show the job categories with current overexposures to beryllium and, thus, the workers for whom beryllium controls would be implemented under the proposed rule.
      Table III-14 summarizes, from the exposure profiles, the number of workers at risk from beryllium exposure and the distribution of 8-hour TWA respirable beryllium exposures by affected job category and sector.  Exposures are grouped into the following ranges:  less than 0.1 μg/m[3]; >= 0.1 μg/m[3] and <= 0.2 μg/m[3]; > 0.2 μg/m[3] and <= 0.5 μg/m[3]; > 0.5 μg/m[3] and <= 1.0 μg/m[3]; > 1.0 μg/m[3] and <= 2.0 μg/m[3]; and greater than 2.0 μg/m[3].  These frequencies represent the percentages of production employees in each job category and sector currently exposed at levels within the indicated range.
      Table III-15 presents data by NAICS code on the estimated number of workers currently at risk from beryllium exposure, as well as the estimated number of workers at risk of beryllium exposure above 0 μg/m[3], at or above 0.1 μg/m[3], at or above 0.2 μg/m[3], at or above 0.5 μg/m[3], at or above 1.0 μg/m[3], and at or above 2.0 μg/m[3].  As shown, an estimated 12,105 workers currently have beryllium exposures at or above the proposed action level of 0.1 μg/m[3]; and an estimated 8,095 workers currently have beryllium exposures above the proposed PEL of 0.2 μg/m[3].

REFERENCES

ADA, 2011. Personal communication between Bennett Napier, Co-Executive Director, The National Association of Dental Laboratories, Tallahassee, Florida, and  Eastern Research Group, Inc., Lexington, Massachusetts. October 4.

Barbetti, K., 2002.  Telephone conversation between Kerry Barbetti, Safety Director, Progress Casting Group and John L. Bennett, consultant to Eastern Research Group, Inc.  February 13, 2002.

BLS, 2010. Occupational Employment Statistics Survey, U.S. Bureau of Labor Statistics. 2010.

Brush Wellman, 2004.  Individual full-shift personal breathing zone (lapel-type) exposure
	levels collected by Brush Wellman in 1999 at their Elmore, Ohio facility were
	provided to ERG in August 2004.  Brush Wellman, Inc., Cleveland, Ohio.

Burnett, W., 2001.  Telephone conversation between Wade Burnett, Sales Manager, NSRW, Inc. and John L. Bennett, consultant to Eastern Research Group, Inc., December 10, 2001.

Cascone, P., 2012. Personal communication between Paul Cascone, Senior Vice President Technology, Argen, Inc., San Diego, California, and Eastern Research Group, Inc., Lexington, Massachusetts. October 19, 2012.

Cascone, 2013. Personal communication between Paul Cascone, Senior Vice President Technology, Argen, Inc., San Diego, California, and Eastern Research Group, Inc., Lexington, Massachusetts. January 10.

CDA, 2002. Copper-Beryllium Suppliers. Based on a list from the Copper Development Association Inc., New York, New York. Copper Development Association website. Available at www.copper.org/resources/suppliers/homepage.html. Original access date unavailable.

Diroccho, S., 2002.  Telephone conversation between Steve Diroccho, Sales Representative, KB Alloys and John L. Bennett, consultant to Eastern Research Group, Inc., January 16, 2002.

ERG, 2003. Beryllium Site 2. Site visit to a precious and base metals recovery facility, January 13 - 15, 2003. Eastern Research Group, Inc., Lexington, Massachusetts. Recorded as a supporting document at www.regulations.gov, OSHA Docket OSHA-H005C-2006-0870, Exhibit 0341.

ERG, 2005.  Cost Sections by Industry Sectors. Version March, 2005. Eastern Research Group, Inc. Draft report submitted to OSHA. OSHA Docket OSHA-H005C-2006-0870, Exhibit 0345.

ERG, 2013. Memorandum: Dental Laboratory Guide.  Eastern Research Group, Inc., May 21, 2013.

Foley, S., 2001.  Telephone conversation between Shane Foley, Sales Representative, EMC Welding Supply and John L. Bennett, consultant to Eastern Research Group, Inc., December 13, 2001.

Green, D., 2001.  Telephone conversation between Dan Green, Sales Representative, Retek, Inc. and John L. Bennett, consultant to Eastern Research Group, Inc., December 13, 2001.

Greskevitch, M., 2000.  Personal e-mail communication between Mark Greskevitch of the U.S. National Institute for Occupational Safety and Health (NIOSH) and Eastern Research Group, Inc., February 17, 2000.

KB, 2002.  Products -- Specialty Alloys.  KB Alloys Website.  Accessed January 16, 2002. (website no longer available).

Kolanz, M., 2001.  Brush Wellman Customer Data Summary.  OSHA Presentation, July 2, 2001. Washington, DC.

Kosto, T., 2002.  Telephone conversations between Tim Kosto, Millward Alloys, Inc. and John L. Bennett, consultant to Eastern Research Group, Inc.  February 6 and 13, 2002.

Lefgren, J., 2002.  Telephone conversation between John Lefgren, President, Emron Metal and John L. Bennett, consultant to Eastern Research Group, Inc., January 31, 2002.

Materion 2002. Docket H005C, Ex. 6-9-5-3. OSHA Docket H005C-2006-0870, Exhibit 0092.

Meeker, J.D., P. Susi, and A. Pellegrino, 2006.  Case Study: Comparison of Occupational Exposures Among Painters Using Three Alternative Blasting Abrasives.  Journal of Occupational and Environmental Hygiene 3(9): D80-D84.

Mitchell, E., 2001.  Telephone conversation between Ed Mitchell, Technical Services, American Welding Society and John L. Bennett, consultant to Eastern Research Group, Inc., December 7, 2001.

Mulcahy, 2002.  Telephone conversation between Rob Mulcahy, KB Alloys and John L.
	Bennett, consultant to Eastern Research Group, Inc., February 1, 2002.

NJMRC, 2003.  National Jewish Medical and Research Center, 2003. Occupational Exposure to Beryllium: Request for Information.  OSHA Docket OSHA-H005C-2006-0870, Exhibit 0155. February 20, 2003.

OSHA, 2009. Integrated Management Information System (IMIS). Beryllium exposure data, updated April 21, 2009. Data provided to Eastern Research Group, Inc. by the U.S. Department of Labor, Occupational Safety and Health Administration, Washington, D.C. [Unpublished, electronic files].

Pekrul, Elissa, 2004.  Telephone conversation between Eastern Research Group, Inc. and Elissa Pekrul, contractor to Communications and Power Industries.  December 2, 2004.

Pelkey, P., 2001.  Telephone conversation between Mark Pelkey, Copper Products, Inc. and John L. Bennett, consultant to Eastern Research Group, Inc., January 2, 2001.

SBAR, 2008. SBAR Panel Final Report, OSHA Docket OSHA-H005C-2006-0870,  Exhibit 0345.

Thomas Register, 2002. Companies Manufacturing Beryllium Copper Connectors. Thomas Register of American Manufacturers website. Available online at: http://www.thomasregister.com. Accessed February 13 and 21.

Thomas Net, 2006. Companies Manufacturing Beryllium Copper Electronic Connectors. Thomas Net website. Available online at: http://www.thomasnet.com. Accessed December 6, 2006.

U.S. Census Bureau, 2004.  2002 Economic Census. Available at http://www.census.gov/econ/census02/.

U.S. Census Bureau, 2007a. 2007 Economic Census. Available at http://www.census.gov/econ/census07/.

U.S. Census Bureau, 2007b. 2007 County Business Patterns. Available  at http://www.census.gov/econ/cbp/index.html.

U.S. Census Bureau, 2010. County Business Patterns: 2010. Available  at http://www.census.gov/econ/cbp/index.html.

Wood, 2001. Telephone conversation between Jim Wood, Regulatory Compliance Officer, Spring Manufacturers Association and Eastern Research Group, Inc. November 13
CHAPTER IV: Technological Feasibility Analysis
EXECUTIVE SUMMARY
This section summarizes the technological feasibility analysis presented in Chapter IV of the PEA (OSHA, 2014).  The technological feasibility analysis includes information on current exposures, descriptions of engineering controls and other measures to reduce exposures, and a preliminary assessment of the technological feasibility of compliance with the proposed standard, including a reduction in OSHA's  permissible exposure limits (PELs) in nine affected application groups.  The current PELs for beryllium are 2.0 μg/m[3] as an 8-hour time weighted average (TWA), and 5.0 μg/m[3] as an acceptable ceiling concentration.  OSHA is proposing a PEL of 0.2 μg/m[3] as an 8-hour TWA and is additionally considering alternative TWA PELs of 0.1 and 0.5 μg/m[3].  OSHA is also proposing a 15-minute short-term exposure limit (STEL) of 2.0  μg/m[3], and is considering alternative STELs of 0.5, 1.0 and 2.5 μg/m[3].
The technological feasibility analysis includes nine application groups that correspond to specific industries or production processes that OSHA has preliminarily determined fall within the scope of the proposed standard.  Within each of these application groups, exposure profiles have been developed that characterize the distribution of the available exposure measurements by job title or group of jobs.  Descriptions of existing engineering controls for operations that create sources of beryllium exposure, and of additional engineering and work practice controls that can be used to reduce exposure are also provided.  For each application group, a preliminary determination is made regarding the feasibility of achieving the proposed permissible exposure limits.  For application groups in which the median exposures for some jobs exceed the proposed TWA PEL, a more detailed analysis is presented by job or group of jobs within the application group.  The analysis is based on the best information currently available to the Agency, including a comprehensive review of the industrial hygiene literature, National Institute for Occupational Safety and Health (NIOSH) Health Hazard Evaluations and case studies of beryllium exposure, site visits conducted by an OSHA contractor (Eastern Research Group (ERG)), submissions to OSHA's rulemaking docket, and inspection data from OSHA's Integrated Management Information System (IMIS).  OSHA also obtained information on production processes, worker exposures, and producer in the United States, Materion Corporation, and from interviews with industry experts.
The nine application groups included in this analysis were identified based on information obtained during preliminary rulemaking activities that included a SBRFA panel, a comprehensive review of the published literature, stakeholder input, and an analysis of IMIS data collected during OSHA workplace inspections where detectable airborne beryllium was found.  The nine application groups and their corresponding section numbers in Chapter IV of the PEA are:
Section 3 -- Beryllium Production,
Section 4 -- Beryllium Oxide Ceramics and Composites,
Section 5 -- Nonferrous Foundries,
Section 6 -- Secondary Smelting, Refining, and Alloying,
Section 7 -- Precision Turned Products,
Section 8 -- Copper Rolling, Drawing, and Extruding,
Section 9 -- Fabrication of Beryllium Alloy Products,
Section 10 -- Welding, and
Section 11 -- Dental Laboratories.
OSHA developed exposure profiles by job or group of jobs using exposure data at the application, operation or task level to the extent that such data were available.  In those instances where there were insufficient exposure data to create a profile, OSHA used analogous operations to characterize the operations.  The exposure profiles represent baseline conditions with existing controls for each operation with potential exposure.  For job groups where exposures were above the proposed TWA PEL of 0.2 μg/m[3], OSHA identified additional controls that could be implemented to reduce employee exposures to beryllium.  These included engineering controls, such as process containment, local exhaust ventilation and wet methods for dust suppression, and work practices, such as improved housekeeping and the prohibition of compressed air for cleaning beryllium-contaminated surfaces.
For the purposes of this technological feasibility assessment, these nine application groups can be divided into three general categories based on current exposure levels:
application groups in which current exposures for most jobs are already below the proposed PEL of 0.2 μg/m[3];
application groups in which exposures for most jobs are below the current PEL, but exceed the proposed PEL of 0.2 μg/m[3], and therefore additional controls would be required; and
application groups in which exposures in one or more jobs routinely exceed the current PEL, and therefore substantial reductions in exposure would be required to achieve the proposed PEL.
The majority of exposure measurements taken in the application groups in the first category are already at or below the proposed PEL of 0.2 μg/m[3], and most of the jobs with exposure to beryllium in these four application groups have median exposures below the alternative PEL of 0.1 μg/m[3] (See Table IV-1 located at the end of this summary). These four application groups include rolling, drawing, and extruding; fabrication of beryllium alloy products; welding; and dental laboratories.
The two application groups in the second category include: precision turned products and secondary smelting.  For these two groups, the median exposures in most jobs are below the current PEL, but the median exposure levels for some job groups currently exceed the proposed PEL.  Additional exposure controls and work practices could be implemented that the Agency has preliminarily concluded would reduce exposures to or below the proposed PEL for most jobs most of the time.  One exception is furnace operations in secondary smelting, in which the median exposure exceeds the current PEL.  Furnace operations involve high temperatures that produce significant amounts of fumes and particulate that can be difficult to contain.  Therefore, the proposed PEL may not be feasible for most furnace operations involved with secondary smelting, and in some cases, respiratory protection would be required to adequately protect furnace workers when exposures exceed 0.2 ug/m[3] despite the implementation of all feasible controls.
Exposures in the third category of application groups routinely exceed the current PEL for several jobs.  The three application groups in this category include: beryllium production, beryllium oxide ceramics production, and aluminum and copper foundries.  The individual job groups for which exposures exceed the current PEL are discussed in the application group specific sections later in this summary, and described in greater detail in the PEA.  For the jobs that routinely exceed the current PEL, OSHA identified additional exposure controls and work practices that the Agency preliminarily concludes would reduce exposures to or below the proposed PEL most of the time, with three exceptions: furnace operations in primary beryllium production and aluminum and copper foundries, and shakeout operations at aluminum and copper foundries.  For these jobs, OSHA recognizes that even after installation of feasible controls, respiratory protection may be needed to adequately protect workers.
In conclusion, the preliminary technological feasibility analysis shows that for the majority of the job groups evaluated, exposures are either already at or below the proposed PEL, or can be adequately controlled with additional engineering and work practice controls.  Therefore, OSHA preliminarily concludes that the proposed PEL of 0.2 μg/m[3] is feasible for most operations most of the time.  The preliminary feasibility determination for the proposed PEL is also supported by Materion Corporation, the sole primary beryllium production company in the U.S., and by the United Steelworkers, who jointly submitted a draft proposed standard that specified an exposure limit of 0.2 μg/m[3] to OSHA (Materion and Steelworkers, 2012).  The technological feasibility analysis conducted for each application group is briefly summarized below, and a more detailed discussion is presented in Sections 3 -- Beryllium Production through 11 -- Dental Laboratories of Chapter IV of the PEA (OSHA, 2014).
Based on the currently available evidence, it is more difficult to determine whether an alternative PEL of 0.1 μg/m[3] would also be feasible in most operations.  For some application groups, such as fabrication of beryllium alloy products, a PEL of 0.1 μg/m[3] would almost certainly be feasible.  In other application groups, such as precision turned products, a PEL of 0.1 μg/m[3] appears feasible, except for establishments working with high beryllium content alloys.  For application groups with the highest exposure, the exposure monitoring data necessary to more fully evaluate the effectiveness of exposure controls adopted after 2000 are not currently available to OSHA, which makes it difficult to determine the feasibility of achieving exposure levels at or below 0.1 μg/m[3].
OSHA also evaluated the feasibility of a STEL of 2.0 μg/m[3], and alternative STELs of 0.5 and 1.0 μg/m[3].  An analysis of the available short-term exposure measurements presented in Chapter IV, Section 12 -- Short-Term Exposures of the PEA, indicates that elevated exposures can occur during short-term tasks such as those associated with the operation and maintenance of furnaces at primary beryllium production facilities, at aluminum and copper foundries, and at secondary smelting operations.  Peak exposure can also occur during the transfer and handling of beryllium oxide powders.  (OSHA, 2009; NEHC, 2003) OSHA believes that in many cases, reducing short-term exposures will be necessary to reduce workers' TWA exposures to or below the proposed PEL.  The majority of the available short-term measurements are below 2.0 μg/m[3], therefore OSHA preliminarily concludes that the proposed STEL of 2.0 μg/m[3] can be achieved for most operations most of the time.  OSHA recognizes that for a small number of tasks, short-term exposures may exceed the proposed STEL, even after feasible control measures to reduce TWA exposure to below the proposed PEL have been implemented, and therefore assumes that the use of respiratory protection will continue to be required for some short-term tasks.  It is more difficult based on the currently available evidence to determine whether the alternative STEL of 1.0 μg/m[3] would also be feasible in most operations based on lack of detail in the activities of the workers presented in the data.  OSHA expects additional use of respiratory protection would be required for tasks in which peak exposures can be reduced to less than 2.0 ug/m[3], but not less than 1.0 ug/m[3].  Due to limitations in the available sampling data and the higher detection limits for short term measurements, OSHA could not determine the percentage of the STEL measurements that are less than or equal to 0.5 ug/m[3].  A detailed discussion of the STELs being considered by OSHA is presented in Section 12 -- Short-Term Exposures of Chapter IV of the PEA (OSHA, 2014).
OSHA requests available exposure monitoring data and comments regarding the effectiveness of currently implemented control measures and the feasibility of the PELs under consideration, particularly the proposed TWA PEL of 0.2 μg/m[3], the alternative TWA PEL of 0.1 μg/m[3], the proposed STEL of 2.0 ug/m[3], and the alternative STEL of 1.0 ug/m[3] to inform the Agency's final feasibility determinations.
APPLICATION GROUP SUMMARIES
This section summarizes the technological feasibility analysis for each of the nine application groups affected by the proposed standard.  Chapter IV of the PEA, Technological Feasibility Analysis, identifies specific jobs or job groups with potential exposure to beryllium, and presents exposure profiles for each of these job groups (OSHA, 2014).  Control measures and work practices that OSHA believes can reduce exposures are described along with preliminary conclusions regarding the feasibility of the proposed PEL.  Table IV-1, located at the end of this summary, presents summary statistics for the personal breathing zone samples taken to measure full-shift exposures to beryllium in each application group.  For the five application groups in which the median exposure level for at least one job group exceeds the proposed PEL, the sampling results are presented by job group.  Table IV-1 displays the number of measurements; the range, the mean and the median of the measurement results; and the percentage of measurements less than 0.1 μg/m[3], less than or equal to the proposed PEL of 0.2 μg/m[3], and less than or equal to the current PEL of 2.0 μg/m[3].  A more detailed discussion of exposure levels by job or job group for each application group is provided in Chapter IV of the PEA, Sections 3 -- Beryllium Production through 11 -- Dental Laboratories, along with a description of the available exposure measurement data, existing controls, and additional controls that would be required to achieve the proposed PEL.
Beryllium Production
Only one primary beryllium production facility is currently in operation in the United States, a plant owned and operated by Materion Corporation, located in Elmore, Ohio.  OSHA identified eight job groups at this facility in which workers are exposed to beryllium.  These include: chemical operations, powdering operations, production support, cold work, hot work, site support, furnace operations, and administrative work.
The Agency developed an exposure profile for each of these eight job groups to analyze the distribution of exposure levels associated with primary beryllium production. The job exposure profiles are based primarily on full-shift personal breathing zone (PBZ) (lapel-type) sample results from air monitoring conducted by Brush Wellman's primary production facility in 1999 (Brush Wellman Elmore, 2004).  Starting in 2000, the company developed the Materion Worker Protection Program (MWPP), a multi-faceted beryllium exposure control program designed to reduce airborne exposures for the vast majority of workers to less than an internally established exposure limit of 0.2 μg/m[3].  According to information provided by Materion, a combination of engineering controls, work practices, and housekeeping were used together to  reduce average exposure levels to below 0.2 ug/m[3] for the majority of workers (Materion Information Meeting, 2012).  Also, two operations with historically high exposures, the wet plant and pebble plants, were decommissioned in 2000, thereby reducing average exposure levels.  Therefore, the samples taken prior to 2000 may overestimate current exposures.
Additional exposure samples were taken by NIOSH at the Elmore facility from 2007 through 2008 (NIOSH Elmore database, 2011). This dataset, which was made available to OSHA by Materion, contains fewer samples than the 1999 survey. OSHA did not incorporate these samples into the exposure profile due to the limited documentation associated with the sampling data. The lack of detailed information for individual samples has made it difficult for OSHA to correlate job classifications and identify the working conditions associated with the samples. Also, OSHA does not know if a sampling strategy was used by NIOSH and Materion to identify the most problematic exposure areas, or if some other sampling strategy was employed.  In a meeting in May 2012 held between OSHA and Materion Corporation at the Elmore facility, the Agency was able to obtain some general information on the exposure control modifications that Materion Corporation made between 1999 and 2007, but has been unable to determine what specific controls were in place at the time NIOSH conducted sampling (Materion Information Meeting, 2012).
In five of the primary production job groups (i.e., hot work, cold work, production support, site support, and administrative work), the baseline exposure profile indicates that exposures are already lower than the proposed PEL of 0.2 μg/m[3].  Median exposure values for these job groups range from nondetectable to 0.08 μg/m[3].
For three of the job groups involved with primary beryllium production, (i.e., chemical operations, powdering, and furnace operations), the median exposure level exceeds the proposed PEL of 0.2 μg/m[3].  Median exposure values for these job groups are 0.47, 0.37, and 0.68 μg/m[3] respectively, and only 17% to 29% of the available measurements are less than or equal to 0.2 μg/m[3] (Brush Wellman Elmore, 2004).  Therefore, additional control measures for these job groups would be required to achieve compliance with the proposed PEL.  OSHA has identified several engineering controls that the Agency preliminarily concludes can reduce exposures in chemical processes and powdering operations to less than or equal to 0.2 ug/m[3].  In chemical processes, these include fail-safe drum-handling systems, full enclosure of drum-handling systems, ventilated enclosures around existing drum positions, automated systems to prevent drum overflow, and automated systems for container cleaning and disposal such as those designed for hazardous powders in the pharmaceutical industry.  Similar engineering controls would reduce exposures in powdering operations.  In addition, installing remote viewing equipment (or other equally effective engineering controls) to eliminate the need for workers to enter the die-loading hood during die filling will reduce exposures associated with this powdering task and reduce powder spills.  Based on the availability of control methods to reduce exposures for each of the major sources of exposure in chemical operations, OSHA preliminarily concludes that exposures at or below the proposed 0.2 g/m[3] PEL can be achieved in most chemical and powdering operations most of the time.  OSHA believes furnace operators' exposures can be reduced using appropriate ventilation, including fume capture hoods, and other controls to reduce overall beryllium levels in foundries, but is not certain whether the exposures of furnace operators can be reduced to the proposed PEL with currently available technology.  OSHA requests additional information on current exposure levels and the effectiveness of potential control measures for primary beryllium production operations to further refine this analysis.
Beryllium Oxide Ceramics Production
OSHA identified seven job groups involved with beryllium oxide ceramics production.  These include: material preparation operator, forming operator, machining operator, kiln operator, production support, metallization, and administrative work.  Four of these jobs (material preparation, forming operator, machining operator and kiln operator) work directly with beryllium oxides, and therefore these jobs have a high potential for exposure.  The other three job groups (production support work, metallization, and administrative work) have primarily indirect exposure that occurs only when workers in these jobs groups enter production areas and are exposed to the same sources to which the 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 workers performing these tasks may at times be directly exposed to beryllium.
The Agency developed exposure profiles for these jobs based on air sampling data from four sources:  1) samples taken between 1994 and 2003 at a large beryllium oxide ceramics facility (OSHA-H005C-2006-0870-0094), 2) air sampling data obtained during a site visit to a primary beryllium oxide ceramics producer (ERG Beryllium Site 3, 2003), 3) a published report that provides information on beryllium oxide ceramics product manufacturing for a slightly earlier time period (Kreiss et al., 1996), and 4) exposure data from OSHA's Integrated Management Information System (OSHA, 2009).  The exposure profile indicates that the three job groups with mostly indirect exposure (production support work, metallization, and administrative work) already achieve the proposed PEL of 0.2 μg/m[3].  Median exposure sample values for these job groups did not exceed 0.06 μg/m[3].
The four job groups with direct exposure had higher exposures.  In forming operations and machining operations, the median exposure levels of 0.18 and 0.15 ug/m[3], respectively, are below the proposed PEL, while the median exposure levels for material preparation and kiln operations of 0.41 μg/m[3] and 0.25 μg/m[3], respectively, exceed the proposed PEL.
The profile for the directly exposed jobs may overestimate exposures due to the preponderance of data from the mid-1990s, a time period prior to the implementation of a variety of exposure control measures introduced after 2000.  In forming operations, 44% of sample values in the exposure profile exceeded 0.2 ug/m[3].  However, the median exposure levels for some tasks, such as small-press and large-press operation, based on sampling conducted in 2003 were below 0.1 ug/m[3].  The exposure profile for kiln operation was based on three samples taken from a single facility in 1995, and are all above 0.2 ug/m[3].  Since then, exposures at the facility have declined due to changes in operations that reduced the amount of time kiln operators spend in the immediate vicinity of the kilns, as well as the discontinuation of a nearby high-exposure process.  More recent information communicated to OSHA suggests that current exposures for kiln operators at the facility are currently below 0.1 ug/m[3].  Exposures in machining operations, most of which were already below 0.2 ug/m3 during the 1990s, may have been further reduced since then through improved work practices and exposure controls (PEA Chapter IV, Section 7 -- Precision Turned Products). For forming, kiln, and machining operations, OSHA preliminarily concludes that the installation of additional controls such as machine interlocks (for forming) and improved enclosures and ventilation will reduce exposures to or below the proposed PEL most of the time.  OSHA requests information on recent exposure levels and controls in beryllium oxide forming and kiln operations to help the Agency evaluate the effectiveness of available exposure controls for this application group.
In the exposure profile for material preparation, 73% of sample values exceeded 0.2 ug/m[3].  As with other parts of the exposure profile, exposure values from the mid-1990s may overestimate airborne beryllium levels for current operations.  During most material preparation tasks, such as material loading, transfer, and spray drying, OSHA preliminarily concludes that exposures can be reduced to or below 0.2 ug/m[3] with process enclosures, ventilation hoods, and improved housekeeping procedures.  However, OSHA acknowledges that peak exposures from some short-term tasks such as servicing of the spray chamber might continue to drive the TWA exposures above 0.2 ug/m[3] on days when these material preparation tasks are performed.  Respirators may be needed to protect workers from exposures above the proposed TWA PEL during these tasks.  OSHA notes that material preparation for production of beryllium oxide ceramics currently takes place at only two facilities in the United States.
Nonferrous Foundries
OSHA identified eight job groups in aluminum and copper foundries with beryllium exposure: molding, material handling, furnace operation, pouring, shakeout operation, abrasive blasting, grinding/finishing, and maintenance.  The Agency developed exposure profiles based on an air monitoring survey conducted by NIOSH in 2007, a Health Hazard Evaluation (HHE) conducted by NIOSH in 1975, a site visit by ERG in 2003, a site visit report from 1999 by the California Cast Metals Association (CCMA), and two sets of data from air monitoring surveys obtained from Materion in 2004 and 2010 (NIOSH EPHB 326-11a; NIOSH EPHB 326-16a ; NIOSH HHE 75-087-280;  ERG Beryllium Site 7, 2003; CCMA, 2000; MC Pkg I-D, 2010).
The exposure profile indicates that in foundries processing beryllium alloys, six of the eight job groups have median exposures that exceed the proposed PEL of 0.2 μg/m[3] with baseline working conditions.  One exception is grinding/finishing operations, where the median value is 0.12 μg/m[3] and 73% of exposure samples are below 0.2 μg/m[3].  The other exception is abrasive blasting. The samples for abrasive blasting used in the exposure profile were obtained during blasting operations using enclosed cabinets, and all 5 samples were below 0.2 μg/m[3].  Exposures for other job groups ranged from just below to well above the proposed PEL, including molder (all samples above 0.2 μg/m[3]), material handler (1 sample total , above 0.2 μg/m[3]), furnace operator (81.8% of samples above 0.2 μg/m[3]), pouring operator (60% of samples above 0.2 μg/m[3]), shakeout operator (1 sample total, above 0.2 μg/m[3]), and maintenance worker (50% of samples above 0.2 μg/m[3]).
In some of the foundries at which the air samples included in the exposure profile were collected, there are indications that the ventilation systems were not properly used or maintained, and dry sweeping or brushing and the use of compressed air systems for cleaning may have contributed to high dust levels. OSHA believes that exposures in foundries can be substantially reduced by improving and properly using and maintaining the ventilation systems; switching from dry brushing, sweeping and compressed air to wet methods and use of HEPA-filtered vacuums for cleaning molds and work areas; enclosing processes; automation of high-exposure tasks; and modification of processes (e.g., switching from sand-based to alternative casting methods).  OSHA preliminarily concludes that these additional engineering controls and modified work practices can be implemented to achieve the proposed PEL most of the time for molding, material handling, maintenance, abrasive blasting, grinding/finishing, and pouring operations at foundries that produce aluminum and copper beryllium alloys.
The Agency is less confident that exposure can be reliably reduced to the proposed PEL for furnace and shakeout operators.  Beryllium concentrations in the proximity of the furnaces are typically higher than in other areas due to the fumes generated and the difficulty of controlling emissions during furnace operations.  The exposure profile for furnace operations shows a median beryllium exposure level of 1.14 μg/m[3].  OSHA believes that furnace operators' exposures can be reduced using local exhaust ventilation and other controls to reduce overall beryllium levels in foundries, but it is not clear that they can be reduced to the proposed PEL with currently available technology.   In foundries that use sand molds, the shakeout operation typically involves removing the freshly cast parts from the sand mold using a vibrating grate that shakes the sand from castings.  The shakeout equipment generates substantial amounts of airborne dust that can be difficult to contain, and therefore shakeout operators are typically exposed to high dust levels.  During casting of beryllium alloys, the dust may contain beryllium and beryllium oxide residues dislodged from the casting during the shakeout process.  The exposure profile for the shakeout operations contains only one result of 1.3 μg/m[3].  This suggests that a substantial reduction would be necessary to achieve compliance with a proposed PEL of 0.2 μg/m[3].  OSHA requests additional information on recent employee exposure levels and the effectiveness of dust controls for shakeout operations for copper and aluminum alloy foundries.
Secondary Smelting, Refining, and Alloying
OSHA identified two job groups in this application group with exposure to beryllium: mechanical process operators and furnace operations workers.  Mechanical operators handle and treat source material, and furnace operators run heating processes for refining, melting, and casting metal alloy.  OSHA developed exposure profiles for these jobs based on exposure data from ERG site visits to a precious/base metals recovery facility and a facility that melts and casts beryllium-containing alloys, both conducted in 2003 (ERG Beryllium Site 2, 2003; ERG Beryllium Site 7, 2003).  The available exposure data for this application group are limited, and therefore, the exposure profile is supplemented in part by summary data presented in secondary sources of information on beryllium exposures in this application group.
The exposure profile for mechanical processing operators indicates low exposures (3 samples less than 0.2 μg/m[3]), even though these samples were collected at a facility where the ventilation system was allowing visible emissions to escape exhaust hoods.  Summary data from studies and reports published in 2005-2009 showed that mechanical processing operator exposures averaged between 0.01 and 0.04 μg/m[3] at facilities where mixed or electronic waste including beryllium alloy parts were refined.  Based on these results, OSHA preliminarily concludes that the proposed PEL is already achieved for most mechanical processing operations most of the time, and exposures could be further reduced through improved ventilation system design and other measures, such as process enclosures.
As with furnace operations examined in other application groups, the exposure profile indicates higher worker exposures for furnace operators in the secondary smelting, refining, and alloying application group (six samples with a median of 2.15 μg/m[3], and 83.3% above 0.2 μg/m[3]).  The two lowest samples in this job's exposure profile (0.03 and 0.5 μg/m[3]) were collected at a facility engaged in recycling and recovery of precious metals where work with beryllium-containing material is incidental.  At this facility, the furnace is enclosed and fumes are ducted into a filtration system.  The four higher samples, ranging from 1.92 to 14.08 μg/m[3], were collected at a facility engaged primarily in beryllium alloying operations, where beryllium content is significantly higher than in recycling and precious metal recovery activities, the furnace is not enclosed, and workers are positioned directly in the path of the exhaust ventilation over the furnace.  OSHA believes these exposures could be reduced by enclosing the furnace and repositioning the worker, but is not certain whether the reduction achieved would be enough to bring exposures down to the proposed PEL.  Based on the limited number of samples in the exposure profile and surrogate data from furnace operations, the proposed PEL may not be feasible for furnace work in beryllium recovery and alloying, and respirators may be necessary to protect employees performing these tasks.
Precision Turned Products
OSHA's preliminary feasibility analysis for precision turned products focuses on machinists who work with beryllium-containing alloys.  The Agency also examined the available exposure data for non-machinists and has preliminarily concluded that, in most cases, controlling the sources of exposures for machinists will also reduce exposures for other job groups with indirect exposure when working in the vicinity of machining operations.
OSHA developed exposure profiles based on exposure data from four NIOSH surveys conducted between 1976 and 2008; ERG site visits to precision machining facilities in 2002, 2003, and 2004; case study reports from six facilities machining copper-beryllium alloys; and exposure data collected between 1987 and 2001 by the U.S. Navy Environmental Health Center (NEHC) (NIOSH HHE 76-103-349, 1976; NIOSH HETA 84-510-1691, 1986; NIOSH EPHB 326-14a, 2008; NIOSH EPHB 326-16a, 2008; NEHC, 2000; NEHC, 2003; ERG Beryllium Site 1, 2002; ERG Beryllium Site 4, 2003; ERG Beryllium Site 9, 2004; Brush Wellman Machining, 2004; OSHA-H005C-2006-0870-0097; Materion PSCS 102, 2011; Materion PSCS 103, 2011; and Materion PSCS 104, 2011).  Analysis of the exposure data showed a substantial difference between the median exposure level for workers machining pure beryllium and/or high-beryllium alloys compared to workers machining low-beryllium alloys.  Most establishments in the precision turned products application group work only with low-beryllium alloys, such as copper-beryllium.  A relatively small number of establishments (estimated at 15) specialize in precision machining of pure beryllium and/or high-beryllium alloys.
The exposure profile indicates that machinists working with low-beryllium alloys have mostly low exposure to airborne beryllium.  Approximately 85 percent of the 80 exposure results are less than or equal to 0.2 ug/m[3], and 74 percent are less than or equal to 0.1 ug/m[3].  Some of the results below 0.1 ug/m[3] were collected at a facility where machining operations were enclosed, and metal cutting fluids were used to control the release of airborne contaminants.  Higher results (0.1 ug/m[3] - 1.07 ug/m[3]) were found at a facility where cutting and grinding operations were conducted in partially enclosed booths equipped with LEV, but some LEV was not functioning properly.  A few very high results (0.77 ug/m[3] - 24 ug/m[3]) were collected at a facility where exposure controls were reportedly inadequate and poor work practices were observed (e.g., improper use of downdraft tables, use of compressed air for cleaning).  Based on these results, OSHA preliminarily concludes that exposures below 0.2 ug/m[3] can be achieved most of the time for most machinists at facilities dealing primarily with low-beryllium alloys.  OSHA recognizes that higher exposures may sometimes occur during some tasks where exposures are difficult to control with engineering methods, such as cleaning, and that respiratory protection may be needed at these times.
Machinists working with high-beryllium alloys have higher exposure than those working with low-beryllium alloys.  This difference is reflected in the exposure profile for this job, where the median of exposure is 0.31 ug/m[3] and 75 percent of samples exceed the proposed PEL of 0.2 ug/m[3].  The exposure profile was based on two machining facilities at which LEV was used and machining operations were performed under a liquid coolant flood.  Like most facilities where pure beryllium and high-beryllium alloys are machined, these facilities also used some combination of full or partial enclosures, as well as work practices to minimize exposure such as prohibiting the use of compressed air and dry sweeping and implementing dust migration control practices to prevent the spread of beryllium contamination outside production areas. At one facility machining high-beryllium alloys, where all machining operations were fully enclosed and ventilated, exposures were mostly below 0.1 ug/m[3] (median 0.035 ug/m[3], range 0.02 - 0.11  ug/m[3]).  Exposures were initially higher at the second facility, where some machining operations were not enclosed, existing LEV system were in need of upgrades, and some exhaust systems were improperly positioned.  Samples collected there in 2003 and 2004 were mostly below the proposed PEL in 2003 (median 0.1 ug/m[3]) but higher in 2004 (median 0.25 ug/m[3]), and high exposure means in both years (1.65 and 0.68 ug/m[3] respectively) show the presence of high exposure spikes in the facility.  However, the facility reported that measures to reduce exposure brought almost all machining exposures below 0.2 ug/m[3] in 2006. With the use of fully enclosed machines and LEV and work practices that minimize worker exposures, OSHA preliminarily concludes that the proposed PEL is feasible for the vast majority of machinists working with pure beryllium and high-beryllium alloys.  OSHA recognizes that higher exposures may sometimes occur during some tasks where exposures are difficult to control with engineering methods, such as machine cleaning and maintenance, and that respiratory protection may be needed at these times.
Copper Rolling, Drawing, and Extruding
OSHA's exposure profile for copper rolling, drawing, and extruding includes four job groups with beryllium exposure: strip metal production, rod and wire production, production support, and administrative work.  Exposure profiles for these jobs are based on personal breathing zone lapel sampling conducted at the Brush Wellman Reading, Pennsylvania, rolling and drawing facility from 1977 to 2000 (Brush Wellman Reading, 2004).
Prior to 2000, the Reading facility had limited engineering controls in place. Equipment in use included LEV in some operations, HEPA vacuums for general housekeeping, and wet methods to control loose dust in some rod and wire production operations.  The exposure profile shows very low exposures for all four job groups.  All had median exposure values below 0.1 ug/m[3], and in strip metal production, production support, and administrative work, over 90 percent of samples were below 0.1 ug/m[3].  In rod and wire production, 70 percent of samples were below 0.1 ug/m[3].
To characterize exposures in extrusion, OSHA examined the results of an industrial hygiene survey of a copper-beryllium extruding process conducted in 2000 at another facility.  The survey reported eight PBZ samples, which were not included in the exposure profile because of their short duration (2 hours).  Samples for three of the four jobs involved with the extrusion process (press operator, material handler, and billet assembler) were below the limit of detection (LOD) (level not reported).  The two samples for the press operator assistant, taken when the assistant was buffing, sanding, and cleaning extrusion tools, were very high (1.6 and 1.9 ug/m[3]).  Investigators recommended a ventilated workstation to reduce exposure during these activities.
In summary, exposures at or below 0.2 ug/m[3] have already been achieved for most jobs in rolling, drawing, and extruding operations, and OSHA preliminarily concludes that the proposed PEL of 0.2 ug/m[3] is feasible for this application group.  For jobs or tasks with higher exposures, such as tool refinishing, use of exposure controls such as local exhaust ventilation can help reduce workers' exposures.  The Agency recognizes the limitations of the available data, which were drawn from two facilities and did not include full-shift PBZ samples for extrusion.  OSHA requests additional exposure data from other facilities in this application group, especially data from facilities where extrusion is performed.
Fabrication of Beryllium Alloy Products
This application group includes the fabrication of beryllium alloy springs, stampings, and connectors for use in electronics.  The exposure profile is based on a study conducted at four precision stamping companies; a NIOSH report on a spring and stamping company; an ERG site visit to a precision stamping, forming, and plating establishment; and exposure monitoring results from a stamping facility presented at the American Industrial Hygiene Conference and Exposition in 2007 (Brush Wellman Stamping, 2004; Corbett, 2007; ERG Beryllium Site 6, 2003; Miller, 2007; NIOSH EPHB 263-12a, 2004).  The exposure profiles for this application group include three jobs: chemical processing operators, deburring operators, and assembly operators.  Other jobs for which all samples results were below 0.1 ug/m[3] are not shown in the profile.
For the three jobs in the profile, the majority of exposure samples were below 0.1 ug/m[3] (deburring operators, 79 percent; chemical processing operators, 81 percent; assembly operators, 93 percent).  Based on these results, OSHA preliminarily concludes that the proposed PEL is feasible for this application group.  The Agency notes that a few exposures above the proposed PEL were recorded for the chemical processing operator (in plating and bright cleaning) and for deburring (during corn cob deburring in an open tumbling mill).  OSHA believes the use of LEV, improved housekeeping, and work practice modifications would reduce the frequency of excursions above the proposed PEL.
Welding
Most of the samples in OSHA's exposure profile for welders in general industry were collected between 1994 and 2001 at two of Brush Wellman's alloy strip distribution centers, and in 1999 at Brush Wellman's Elmore facility (Brush Wellman Stamping, 2004).  At these facilities, tungsten inert gas (TIG) welding was conducted on beryllium alloy strip.  Seven samples in the exposure profile came from a case study conducted at a precision stamping facility, where airborne beryllium levels were very low (see previous summary, Fabrication of Beryllium Alloy Products).  At this facility, resistance welding was performed on copper-beryllium parts, and welding processes were automated and enclosed.
Most of the sample results in the welding exposure profile were below 0.2 ug/m[3].  Of the 44 welding samples in the profile, 75 percent were below 0.2 ug/m[3] and 64 percent were below 0.1 ug/m[3], with most values between 0.01 and 0.05 ug/m[3].  All but one of the 16 exposure samples above 0.1 ug/m[3] were collected in Brush Wellman's Elmore facility in 1999.  According to company representatives, these higher exposure levels may have been due to beryllium oxide that can form on the surface of the material as a result of hot rolling.  All seven samples from the precision stamping facility were below the limit of detection.  Based on these results, OSHA preliminarily concludes that the proposed PEL of 0.2 ug/m[3] is feasible for most welding operations in general industry.
Dental Laboratories
OSHA's exposure profile for dental technicians includes sampling results from a site visit conducted by ERG in 2003 (ERG Beryllium Site 5, 2003); a study of six dental laboratories published by Rom, et al. in (1984); a data set of exposure samples collected between 1987 and 2001, on dental technicians working for the U.S. Navy (NEHC, 2003); and a docket submission from CMP Industries including two samples from a large commercial dental laboratory using nickel-beryllium alloy (OSHA-H005C-2006-0870-0346).  Information on exposure controls in these facilities suggests that controls in some cases may have been absent or improperly used.
The exposure profile indicates that 52 percent of samples are less than or equal to 0.2 ug/m[3].  However, the treatment of nondetectable samples in the feasibility analysis may overestimate many of the sample values in the exposure profile. Twelve of the samples in the profile are nondetectable for beryllium.  In the exposure profile, these were assigned the highest possible value, the limit of detection (LOD). For eight of the nondetectable samples, the LOD was reported as 0.2 ug/m[3].  For the other four nondetectable samples, the LOD was between 0.23 and 0.71 ug/m[3].  If the true values for these four nondetectable samples are actually less than or equal to the assigned value of 0.2 ug/m[3], then the true percentage of profile sample values less than or equal to 0.2 ug/m[3] is between 52 and 70 percent.  Of the sample results with detectable beryllium above 0.2 ug/m[3], some were collected in 1984 at facilities studied by Rom et al., who reported that they occurred during grinding with LEV that was improperly used or, in one case, not used at all.  Others were collected at facilities where little contextual information was available to determine what control equipment or work practices might have reduced exposures.
Based on this information, OSHA preliminarily concludes that beryllium exposures for most dental technicians are already below 0.2 ug/m[3] most of the time.  OSHA furthermore believes that exposure levels can be reduced to or below 0.1 ug/m[3] most of the time via material substitution, engineering controls, and work practices.  Beryllium-free alternatives for casting dental appliances are readily available from commercial so
urces, and some alloy suppliers have stopped carrying alloys that contain beryllium.  For those dental laboratories that continue to use beryllium alloys, exposure control options include properly designed, installed, and maintained LEV systems (equipped with HEPA filters) and enclosures; work practices that optimize LEV system effectiveness; and housekeeping methods that minimize beryllium contamination in the workplace.  In summary, OSHA preliminarily concludes that the proposed PEL is feasible for dental laboratories.

Table IV-1 -- Beryllium Full-Shift PBZ Samples by Application / Job Group  (μg/m[3])
                            Application / Job Group
                                       N
                                     Range
                                     Mean
                                    Median
                                   %<0.1
                                   %<= 0.2
                                   %<= 2.0
Beryllium Production Operations (Section 3)
   Furnace Operations
172
0.05 to 254
3.80
0.68
5%
17%
82%
   Chemical Operations
20
0.05 to 9.6
1.02
0.47
5%
15%
95%
   Powdering Operations
72
0.06 to 11.5
0.82
0.37
11%
29%
94%
   Production Support
861
0.02 to 22.7
0.51
0.08
56%
71%
94%
   Cold Work
555
0.04 to 24.9
0.31
0.08
61%
80%
98%
   Hot Work
297
0.01 to 2.21
0.12
0.06
69%
88%
99%
   Site Support
879
0.05 to 4.22
0.11
0.05
81%
92%
99%
   Administrative
981
0.05 to 4.54
0.10
0.05
85%
94%
99%
Beryllium Oxide Ceramics (Section 4)
   Material Preparation Operator
77
0.02 to 10.6
1.01
0.41
13%
27%
90%
   Forming Operator
408
0.02 to 53.2
0.48
0.18
27%
56%
99%
   Machining Operator
355
0.01 to 5.0
0.32
0.15
37%
63%
98%
   Kiln Operator
3
0.22 to 0.36
0.28
0.25
0%
0%
100%
   Production Support Worker
119
0.02 to 7.7
0.21
0.05
68%
88%
98%
   Metallization Worker
36
0.02 to 0.62
0.15
0.06
55%
69%
100%
   Administrative
185
0.02 to 1.2
0.06
0.05
93%
98%
100%
Nonferrous Foundries (Section 5)
   Furnace Operator
11
0.2 to 19.76
4.41
1.14
0%
18%
64%
   Pouring Operator
5
0.2 to 2.2
1.21
1.40
0%
40%
60%
   Shakeout Operator
1
1.3
1.30
1.30
0%
0%
100%
   Material Handler
1
0.93
0.93
0.93
0%
0%
100%
   Molder
8
0.24 to 2.29
0.67
0.45
0%
0%
88%
   Maintenance
78
0.05 to 22.71
0.87
0.21
15%
50%
96%
   Abrasive Blasting Operator
5
0.05 to 0.15
0.11
0.12
40%
100%
100%
   Grinding/finishing Operator
56
0.01 to 4.79
0.31
0.05
59%
73%
95%
Secondary Smelting (Section 6)
    Furnace operations worker
6
0.03 to 14.1
3.85
2.15
17%
17%
50%
    Mechanical processing operator
3
0.03 to 0.2
0.14
0.20
33%
100%
100%
Precision Turned Products (Section 7)
    High Be Content Alloys
80
0.02 to 7.2
0.72
0.31
14%
25%
92%
    Low Be Content Alloys
59
0.005 to 24
0.45
0.01
74%
85%
96%
Rolling, Drawing, and Extruding
(Section 8)
650
0.006 to 7.8
0.11
0.024
86%
93%
99%
Alloy Fabrication (Section 9)
71
0.004 to 0.42
0.056
0.025
83%
94%
100%
Welding: Beryllium Alloy (Section 10)
44
0.005 to 2.21
0.19
0.02
64%
75%
98%
Dental Laboratories (Section 11)
23
0.02 to 4.4
0.74
0.2
13%
52%
87%

References
Brush Wellman Elmore, 2004.  Brush Wellman's 1999 baseline full-shift personal breathing zone (lapel-type) exposure results for its Elmore, Ohio, primary beryllium production facility.  Data provided to Eastern Research Group, Inc., Lexington, Massachusetts, on August 23, 2004.  [Unpublished]
Brush Wellman Machining, 2004.  Brush Wellman copper-beryllium machining case study exposure results for three machine shops.  Data provided to Eastern Research Group, Inc., Lexington, Massachusetts, on August 23, 2004. [Unpublished]
Brush Wellman Reading, 2004.  Process specific information and individual full-shift personal breathing zone (lapel-type) sample results for the Brush Wellman Reading, Pennsylvania, rolling and drawing facility.  Data provided to Eastern Research Group, Inc., Lexington, Massachusetts, August 23 through December 2004.   [Unpublished]
Brush Wellman Stamping, 2004.  Brush Wellman Copper-Beryllium Stamping Industry Case Study: Consolidated Exposure Assessment Data at Four Precision Stamping Companies. Individual Full-Shift Personal Breathing Zone (Lapel-Type) Sample Results for Four Precision Stamping Companies. Data provided to Eastern Research Group, Inc. Lexington, Massachusetts. August 23. [Unpublished]
CCMA, 2000.  Ventilation Control of Airborne Metals and Silica in Foundries. California Cast Metals Association (CCMA). El Dorado Hills, California.  April.
Corbett, M.L., 2007.  Beryllium Aerosol Exposure Characterization During Chemical Processing of Copper-Beryllium Alloys. Paper presented at the American Industrial Hygiene Conference and Exposition. Podium Session 106. Philadelphia, Pennsylvania. June 2 - 7.
ERG Beryllium Site 1, 2002.  Site visit to an aluminum-beryllium alloy fabrication facility, December 2 - 3, 2002. Eastern Research Group, Inc., Lexington, Massachusetts. Recorded as a supporting document at www.regulations.gov, under Document ID number OSHA-H005C-2006-0870-0341.
ERG Beryllium Site 2, 2003.  Site visit to a precious and base metals recovery facility, January 13 - 15, 2003. Eastern Research Group, Inc., Lexington, Massachusetts. Recorded as a supporting document at www.regulations.gov, under Document ID number OSHA-H005C-2006-0870-0341.
ERG Beryllium Site 3, 2003.  Site visit to a beryllium oxide fabrication facility. Eastern Research Group, Inc., Lexington, Massachusetts. Recorded as a supporting document at www.regulations.gov, under Document ID number OSHA-H005C-2006-0870-0341. January 16 - 17.
ERG Beryllium Site 4, 2003.  Site visit to a beryllium and aluminum-beryllium alloy machining and fabrication facility, January 21 - 23, 2003. Eastern Research Group, Inc., Lexington, Massachusetts. Recorded as a supporting document at www.regulations.gov, under Document ID number OSHA-H005C-2006-0870-0341.
ERG Beryllium Site 5, 2003.  Site visit to a dental laboratory. Eastern Research Group, Inc., Lexington, Massachusetts. January 28 - 29. Recorded as a supporting document at www.regulations.gov, under Document ID number OSHA-H005C-2006-0870-0341.
ERG Beryllium Site 6, 2003.  Site visit to an establishment that specializes in precision stamping, forming, and plating of copper-beryllium parts. Eastern Research Group, Inc. Lexington, Massachusetts. August 26 - 28. Recorded as a supporting document at www.regulations.gov, under Document ID number OSHA-H005C-2006-0870-0341.
ERG Beryllium Site 7, 2003.  Site visit to a copper-beryllium casting facility. Eastern Research Group, Inc. Lexington, Massachusetts. September 16 - 17. Recorded as a supporting document at www.regulations.gov, under Document ID number OSHA-H005C-2006-0870-0341.
ERG Beryllium Site 9, 2004.  Site re-visit to a beryllium and aluminum-beryllium alloy machining and fabrication facility (i.e., ERG Beryllium Site 4), February 3 - 5, 2004. Eastern Research Group, Inc., Lexington, Massachusetts. Recorded as a supporting document at www.regulations.gov, under Document ID number OSHA-H005C-2006-0870-0341.
Kreiss, K., M.M. Mroz, L.S. Newman, J. Martyny, and B. Zhen, 1996.  Machining Risk of Beryllium Disease and Sensitization with Median Exposures Below 2 ug/m[3].  American Journal of Industrial Medicine 30:16 - 25.
Materion and Steelworkers, 2012.  Industry and Labor Joint Submission to OSHA of a Recommended Standard for Beryllium.  February, 2012.
Materion Information Meeting, 2012. Personal communication during meeting between Materion Corporation and OSHA. Elmore, Ohio. May 8-9.
Materion PSCS 102, 2011.  Ram Electrical Discharge Machining (EDM) on Copper Beryllium Alloys. Process Specific Control Summary (PSCS) 102, October 26, 2011. Materion Brush Inc., Mayfield Heights, Ohio. Available online at http://materion.com/~/media/Files/PDFs/Corporate/PSCS/PSCS102EDMonCuBeAlloys.pdf. Accessed May 20, 2012.
Materion PSCS 103, 2011.  Computer Numerically Controlled (CNC) Lathe on Copper Beryllium Alloys. Process Specific Control Summary (PSCS) 103, October 26, 2011. Materion Brush Inc., Mayfield Heights, Ohio. Available online at http://materion.com/~/media/Files/PDFs/Corporate/PSCS/PSCS103CNCLatheonCuBeAlloys.pdf. Accessed May 20, 2012.
Materion PSCS 104, 2011.  Computer Numerically Controlled (CNC) Milling on Copper Beryllium Alloys. Process Specific Control Summary (PSCS) 104, October 26, 2011. Materion Brush Inc., Mayfield Heights, Ohio. Available online at http://materion.com/~/media/Files/PDFs/Corporate/PSCS/PSCS104CNCMillingonCuBe.pdf. Accessed May 20, 2012.
MC Pkg I-D, 2010.  Industrial Hygiene Survey of June 2007 through April 2009 -- Final Report: Plastic blow molding fabrication operations using copper beryllium (CuBe) Alloy 25 inserts; report dated 14 January, 2010. Part D of Information Package I received May 29, 2012, from Materion Corporation by OSHA/DSG/OTF.
Miller, J.R., 2007.  Beryllium Aerosol Exposure Characterization during Precision Stamping of Copper Beryllium Alloy. Paper presented at the American Industrial Hygiene Conference and Exposition. Podium Session 106. Philadelphia, Pennsylvania, June 2-7.
NEHC, 2000.  Navy Occupational Exposure Database. Query for personal breathing zone, eight-hour time-weighted exposure samples for beryllium, August 24, 2000. U.S. Navy Environmental Health Center, Norfolk, Virginia. [Unpublished]
NEHC, 2003.  (1) Navy Response to Occupational Safety and Health Administration's Occupational Exposure to Beryllium; Request for Information. Document ID: OSHA-H005C-2006-0870-0144. (2) Attachment 1. Navy Occupational Exposure Database (NOED) Query Report Personal Breathing Zone Air Sampling Results for Beryllium. Document ID: OSHA-H005C-2006-0870-0145. OSHA Beryllium Docket ID: OSHA-H005C-2006-0870. Navy Environmental Health Center, Portsmouth, VA.  February.
NIOSH Elmore database, 2011. Spreadsheet containing beryllium exposure values collected by NIOSH at the Materion Elmore facility in 2007 and 2008; provided by Materion Corporation to OSHA-Directorate of Standards and Guidance.  Fall 2011.
NIOSH EPHB 263-12a, 2004. Control Technology and Exposure Assessment for Occupational Exposure to Beryllium: Michigan Spring and Stamping, Muskegon, Michigan. Report No. EPHB 263-12a. U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Division of Applied Research and Technology Cincinnati, Ohio. February 5.
NIOSH EPHB 326-11a.  Control Technology and Exposure Assessment for Occupational Exposure to Beryllium: Beryllium Facility #1 -- Copper/Beryllium Foundry. Report No. EPHB 326-11a. U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Division of Applied Research and Technology. Cincinnati, Ohio. July 2008.
NIOSH EPHB 326-14a, 2008.  Control Technology and Exposure Assessment for Occupational Exposure to Beryllium: Beryllium Facility #2 -- Copper/Beryllium Machine Shop. Report No. EPHB 326-14a. U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Division of Applied Research and Technology, Cincinnati, Ohio. (October 2008)
NIOSH EPHB 326-16a.  Control Technology and Exposure Assessment for Occupational Exposure to Beryllium: Beryllium Facility #3 -- Aluminum/Beryllium Foundry, and Copper/Beryllium Foundry and Machine Shop. Report No. EPHB 326-16a. U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Division of Applied Research and Technology. Cincinnati, Ohio. November 2008.
NIOSH HETA 84-510-1691, 1986.  Health Hazard Evaluation Report No. HETA 84-510-1691, Rockwell International, Rocky Flats Plant, Golden, Colorado. U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health. (May 1986)
NIOSH HHE 75-87-280.  Health Hazard Evaluation Determination Report No. 75-87-280, Kawecki Berylco Industries, Inc., Reading, Pennsylvania (NTIS document number PB89-161251). National Institute for Occupational Safety and Health. Cincinnati, Ohio. April 1976.
NIOSH HHE 76-103-349, 1976.  Health Hazard Evaluation Determination Report No. 76-103-349, Hardric Laboratories, Waltham, Massachusetts. U.S. Department of Health, Education, and Welfare, Center for Disease Control, National Institute for Occupational Safety and Health. (December 1976)
OSHA, 2009.  Integrated Management Information System (IMIS).  Beryllium exposure data, updated April 21, 2009, covering the period 1978 through September 2008.  Data provided to Eastern Research Group, Inc. by the U.S. Department of Labor, Occupational Safety and Health Administration, Washington, DC.  [Unpublished, electronic files]
OSHA-H005C-2006-0870-0094.  Document Title: Attachment 2.4.  Beryllium Oxide Ceramic Production and Processing Facility.  Comments submitted by Brush Wellman, Inc. in repsonse to Federal Register of November 26, 2002.  Dated February 21, 2003.
OSHA-H005C-2006-0870-0097.  U.S. Department of Labor, Occupational Safety and Health Administration. OSHA Beryllium Docket No. OSHA-H005C-2006-0870. Document ID No. OSHA-H005C-2006-0870-0097. Attachment 2.7. Facilities Machining Copper Beryllium. Comments received from Brush Wellman Inc. in response to the Federal Register notice of November 26, 2002. Dated February 21, 2003.
OSHA-H005C-2006-0870-0346.  U.S. Department of Labor, Occupational Safety and Health Administration. OSHA Beryllium Docket No. OSHA-H005C-2006-0870. Document ID No. OSHA-H005C-2006-0870-0346. Document title: Appendix C. Beryllium Small Business Advocacy Review (SBAR) Panel Report.
Rom, W.N., J.E. Lockey, J.S. Lee, A.C. Kimball, K.M. Bang, H. Leaman, R.E. Johns, D. Perrota, and H.L. Gibbons, 1984.  Pneumoconiosis and Exposures of Dental Laboratory Technicians. American Journal of Public Health 74(11): 1252 - 1257. November.

Section 1 -- INTRODUCTION
This report presents OSHA's analysis of the technological feasibility of achieving lower levels of beryllium exposure in general industry through the implementation of engineering, administrative, and work practice controls. This analysis and the resultant conclusions are based on a comprehensive review of the available industrial hygiene literature; exposure data and information from a primary beryllium producer; National Institute for Occupational Safety and Health (NIOSH) industry-specific case studies of the sources of beryllium exposure; findings from Eastern Research Group (ERG) and NIOSH site visits; interviews with industry experts; peer-reviewed journal articles; and data from OSHA's Integrated Management Information System (IMIS).
The following sections discuss the methodology and data sources used in this analysis and evaluate the technological feasibility of the proposed permissible exposure limit (PEL) for each of the affected application groups and corresponding industries:
Section 2 -- Methodology
Section 3 -- Beryllium Production
Section 4 -- Beryllium Oxide Ceramics and Composites
Section 5 -- Nonferrous Foundries
Section 6 -- Secondary Smelting, Refining, and Alloying, Including Handling of Scrap and Recycled Materials
Section 7 -- Precision Turned Products
Section 8 -- Copper Rolling, Drawing, and Extruding
Section 9 -- Fabrication of Beryllium Alloy Products
Section 10 -- Welding
Section 11 -- Dental Laboratories
A final section, Section 12 -- Short-Term Exposures, addresses those situations within the affected industries where short-term (15-minute) tasks can generate peak exposures.

SECTION 2 -- METHODOLOGY
Forms of Beryllium
The element beryllium occurs as a metal (beryllium) and as an oxide of the metal (beryllium oxide). Both forms of beryllium have desirable functional characteristics, such as being heat-conducting, electrical-insulating, nonmagnetic, and extremely strong yet lightweight. Metallic beryllium in small amounts improves the properties of metal alloys; it is combined with copper and aluminum to form specialty alloys of these metals. Beryllium oxide forms readily on the untreated surfaces of pure beryllium metal and beryllium-containing alloys. Beryllium oxide is also manufactured and shaped as a ceramic, or ceramic-metal matrix, to produce other specialty products.
This analysis applies to the element beryllium regardless of whether it is present as pure metal, a component of an alloy, or as beryllium oxide.
Sources of Beryllium in Workplace Air Samples
Airborne beryllium occurs where operations generate dusts of beryllium metal or its alloys, either through mechanical action on the beryllium metal or alloy (e.g., grinding, cutting, machining, polishing) or by heating beryllium above its vaporization point (e.g., in a foundry furnace), causing beryllium fumes to be released.
Additionally, airborne beryllium also occurs where beryllium oxide is formed and released:
While melting and pouring beryllium metal and its alloys, during which beryllium oxides are emitted as fume and also accumulate as part of the dross (impurities) that foundry workers skim off the molten metal (deYoung and Peace, 2009).
During casting or heat-treating of metals containing beryllium, on which surface oxides form (Kent, 2012).
Where the oxide is released from surfaces during any manipulation of materials on which the oxide has formed, adhered, collected (e.g., processing beryllium alloy strip, cleaning molds used to cast molten beryllium alloy, servicing industrial ventilation equipment). This can include beryllium particles contained in mist emitted from beryllium alloy surface-treatment tanks in which beryllium has accumulated (Kent, 2012).
During handling of the manufactured beryllium oxide ceramic powder (beryllia) or finishing ceramic products formed from that oxide (Kolanz, 2001).
Beryllium oxide forms readily when metal is heated. Evidence suggests that in molten alloys, beryllium is concentrated as an oxide in dross, even when the alloys contain low concentrations of beryllium. Investigators analyzed beryllium concentrations in dross produced from aluminum alloys of varying concentrations of beryllium (deYoung and Peace, 2009). Under both experimental (one site) and industrial (two sites) conditions, the investigators found that beryllium was more concentrated in the oxide portion of the dross compared to the parent alloy. These findings demonstrate the importance of dross (and beryllium oxide) as a notable source of worker beryllium exposure in operations where dross occurs (i.e., foundries, smelters).
Contractor Report
For this technological feasibility analysis, OSHA relied primarily on reports developed by its contractor Eastern Research Group, Inc. (ERG). ERG initially acquired beryllium exposure data and related information between 2001 and 2004 using literature search and retrieval processes; records provided by OSHA; findings from site visits conducted by ERG and NIOSH; and communications with representatives of NIOSH, identified industries, and other groups.
ERG analyzed the available data using the methods described below, building on the analysis included in a 2005 ERG report to OSHA. A panel convened under the Small Business Regulatory Enforcement Fairness Act (SBREFA) reviewed the report in 2007, after which it was entered in the associated beryllium rulemaking docket. Since then, OSHA has worked with ERG to update the materials, and ERG presented OSHA with additional interim reports through 2011. In general, OSHA finds the logic and methodology of these studies to be sound, the data complete to the extent available, and the analysis compelling. Unless otherwise noted, OSHA concurs with ERG's findings.
OSHA has based this technological feasibility analysis on the best information available from these reports and internal supplemental information that has been created since 2011. The result is the current draft, available as Chapter IV (Technological Feasibility) of the Preliminary Economic Analysis (PEA). Chapter IV reflects all the current data available to OSHA.
Sources of Data
This technological feasibility analysis relies on information from a wide variety of sources available to OSHA. This information is found in ERG's report (ERG, 2005) or in subsequent interim reports, as well as from recent supplemental information. The sources of information include:
Peer-reviewed published literature.
Beryllium records from OSHA's Integrated Management Information System (IMIS).
NIOSH reports, including health hazard evaluations (HHE), control technology (CT) assessments, in-depth surveys, recommendations for exposure control, and engineering control feasibility studies.
ERG site visits.
Brush Wellman, Incorporated (known as Materion Corporation since 2010), the sole primary beryllium producer in the United States.
Unpublished information (e.g., unpublished data and research obtained through personal communications, meetings, presentations, and submissions to OSHA's public docket [OSHA-H005C-2006-0870]).
Information available from other federal agencies, industry organizations, and other groups.
ERG also obtained OSHA IMIS data from 1978 through mid-2008, which primarily were used to identify industries initially considered for inclusion in this technological feasibility analysis.
As noted above, OSHA has mainly relied on the contractor reports (ERG, 2005); however, OSHA has considered and referenced additional material where available.
Notes on Data Sources and Characteristics
OSHA's Integrated Management Information System
For purposes of this analysis, the documentation for individual results in OSHA's IMIS data (1978 through mid-2008) is incomplete. The IMIS record reports the Standard Industrial Classification (SIC) but not the product produced, action performed, or materials used. Furthermore, IMIS does not include information on the sample duration; thus, it was not possible to confirm whether samples were obtained over 60 minutes or 360 minutes or 480 minutes of the worker's shift (or any other time period). The IMIS record reports the worker's job title (a free text field subject to infinite variability, and therefore difficult to sort into job categories), but it does not report the worker's actual activities during the sampling period or the presence of exposure controls.
As intended, IMIS is useful as a management tool for observing trends and identifying industries in which exposures occur. For the detailed industry-by-industry technological feasibility analyses, however, OSHA used more completely documented data sources. OSHA also based application group exposure profiles on other sources, if available.
Limits of Detection for Beryllium Data
Investigators performing data analysis usually follow the common practice of assigning a value to samples with concentrations reported as "nondetectable"(sometimes designated as "ND"). The assigned value is typically related to the reported limit of detection (LOD) and permits the investigator to account for these sample results in quantitative analysis, such as when calculating the mean and median.
The LOD indicates the smallest quantity of beryllium that can be detected. This practical limitation of the laboratory analysis (procedures and analytical equipment) is typically a fixed value for each analytical method. The beryllium LOD can be presented in two formats: as the analytical method LOD, which refers to the smallest mass of beryllium (in micrograms [μg]) that can be detected on the filter, or as the concentration LOD, which refers to a calculated value representing the smallest airborne concentration (in μg/cubic meter [m[3]]) of air that can be detected.
Results below the limit of quantitation (LOQ) are those in which beryllium was detected, but not in sufficient quantity to offer an accurate analytical result (this range is sometimes reported nonquantitatively as "trace"). Like the LOD, the LOQ is a function of the laboratory analytical method. OSHA handled results reported as below the LOQ in the same manner as LOD values (e.g., by assigning the reported value of the LOQ to results reported as the LOQ).
The beryllium analytical method LOD is presented as the number of micrograms of beryllium that can be detected on an individual filter used to collect an air sample. For example, since 2002, OSHA's beryllium analytical method (OSHA ID-125G) has a reported LOD value of 0.013 μg. If particulate matter on a filter contains less than 0.013 μg of beryllium, the analytical process will not be able to measure it. The laboratory technician cannot tell whether the filter holds no beryllium at all or some small amount between 0 μg and the LOD of 0.013 μg. The only certainty is that the amount of beryllium on the filter is less than the LOD. Although historically other LODs have been published for other beryllium analytical methods, commonly cited laboratory methods currently offer an LOD of 0.013 μg or lower for beryllium samples (Ashley, 2007). When a laboratory finds that the mass of beryllium on a filter is not detectable, the laboratory report will generally indicate that the mass is "less than 0.013 μg" (<0.013 μg).
When a laboratory reports that the gravimetric result is not detectable because there is not enough beryllium on the sample filter, the analytical LOD is used to represent the beryllium mass in the concentration calculation. The concentration LOD is calculated by dividing the analytical LOD by the volume of air sampled (measured in cubic meters). For example, if the analytical LOD is 0.013 μg and the air volume sampled is 720 liters (0.720 m[3]), the concentration LOD would be calculated as 0.013 μg/0.720 m[3], or about 0.018 μg/ m[3].
Practical examples of the concentration LOD for beryllium results analyzed using a method with an analytical LOD of 0.013 μg appear in Table IV-2.
Table IV-2 -- Practical Examples of Concentration LODs for Beryllium Results Obtained
Using a Method With an Analytical LOD of 0.013 μg
Sample Duration*
Air Volume Sampled
Calculated Concentration LOD
480 minutes (8 hours)
                            960 Liters (0.960 m[3])
                                0.014 μg/m[3]
360 minutes (6 hours)
                            720 Liters (0.720 m[3])
                                0.018 μg/m[3]
180 minutes (3 hours)
                            360 Liters (0.360 m[3])
                                0.036 μg/m[3]
15 minutes (1/4 hour)
                            30 Liters (0.030 m[3])
                                 0.43 μg/m[3]
*	Also assumes that the air sample was obtained at 2.0 liters/minute, the recommended rate for OSHA's method ID-125G.

The resulting concentration LOD indicates the minimum concentration of airborne beryllium that could have been detected. Because beryllium was not detected, the true airborne concentration is less than the concentration LOD. These LODs vary depending on the volume of air sampled. For a given air sampling rate, a shorter sampling period will always result in a smaller volume of air sampled. Thus, all other factors being equal, a sample collected over a short period will result in a higher LOD than a sample collected over a longer period of time. Two results obtained on the same date at the same location, but involving different volumes of sampled air, will have different LODs.
Several different approaches are available for assigning a value to sample results below the LOD (e.g., assigning a value of one-half the LOD concentration, assigning the unmodified LOD concentration value) (Hornung and Reed, 1990; NIOSH ECTB 233-101c, 1999; Succop et al., 2004). For the purposes of this analysis, OSHA elected to use the unmodified concentration LOD value to be as protective as possible. This probably resulted in a slight overestimation of exposure levels; the true concentration is some unknown level between zero and the LOD.
The full-shift sample results that OSHA analyzed for the exposure profiles included nondetectable results (i.e., samples with concentrations reported as nondetectable or, providing sufficient information was available, OSHA estimated the concentration LOD). When discussing individual airborne concentration results for worker breathing zone samples in which beryllium was not detected, OSHA typically includes a note (e.g., "LOD") indicating that the reported value (e.g., 0.018 μg/ m[3]) is based on a calculated concentration LOD.
By using full-shift results (defined for purposes of this analysis as having a duration of 360 minutes or greater) for general industry, OSHA minimizes the number of results that are less than the LOD. Specifically, when the sample LOD is 0.013 μg, the concentration LOD is 0.018 μg/m[3] or less for sample results included in the exposure profiles that were collected using the sampling pump air flow rate of 2.0 lpm. Even when samples are obtained at a lower sampling rate (e.g., 1.0 lpm), the LOD will be somewhat higher (0.036 μg/ m[3]) but still below 0.1 μg/ m[3] (and therefore in the lowest range of the exposure profile).
Two data sources, Brush Wellman and the U.S. Navy, adjusted all their nondetectable results using other approaches currently practiced for dealing with such values (Hornung and Reed, 1990). For sample results below the LOD, Brush Wellman uses a sample mass one-half the LOD to calculate the nondetectable sample concentration. The U.S. Navy adjusts results that are below the analytical LOD by dividing by the square root of 2 prior to calculating the 8-hour time-weighted average (TWA) ( OSHA-H005C-2006-0870-0145). NIOSH tested a variety of methods for handling the LOD during different studies. For some exposure assessments, NIOSH investigators adjusted results below the LOD in the same manner as the Navy and used the LOD divided by the square root of 2 (LOD/√2) to calculate the LOD concentration (e.g., see NIOSH EPHB 263-13a). In other cases, NIOSH investigators treated nondetectable values using the LOD/2 approximation method, as noted for Brush Wellman (e.g., see NIOSH HETA 83-162-1746). In many cases, the nondetectable sample results, once adjusted, no longer carry the "less than" qualifier in the source document. The Navy and NIOSH data do indicate which sample results are below the analytical LOD; however, this information was not available for the PBZ sampling results for Brush Wellman's operations.
Whenever nondetectable results were adjusted by the data source (e.g., Brush Wellman, NIOSH), ERG analyzed the results as reported by the data sources (e.g., if NIOSH indicated that a concentration was less than the LOD and reported a value of LOD/√2, then ERG used the adjusted value as it was reported by NIOSH).
Methods to Assess Technological Feasibility
Feasibility
OSHA based this analysis on published literature; documents from sources such as NIOSH and other government agencies; trade and industry organizations; IMIS data for beryllium from 1978 through mid-2008; information from industry representatives on typical workplace processes, job categories, available controls, and exposure data; and site visits conducted by ERG.
OSHA evaluated the IMIS data to identify industries in which beryllium had frequently been sampled during OSHA inspections, and in which analytical results frequently showed detectable airborne beryllium in the workplace. Based on these results and information from the available literature, OSHA developed a preliminary list of industries to be included in the technological feasibility analysis. The list was adjusted as information warranted, and a list of affected job categories with notable exposure to beryllium was developed for each industry.
Beryllium exposure data for each job category in each industry were identified in the retrieved literature and other information sources. These results formed the basis for the initial exposure profiles, which were presented along with process descriptions and methods of exposure control in the contractor report, available in the beryllium docket as OSHA-H005C-2006-0870-0340 under the title Technological Feasibility Materials.
For this technological feasibility analysis, OSHA relied on the contractor report (ERG, 2005) and included the same industries and job categories addressed in those documents, with some modifications. OSHA also received more recent materials through June 2012. Where additional information was available, OSHA incorporated it into the current analysis, so that all the current data are reflected in Chapter IV of this PEA. Industries included in this analysis are those identified as having the potential for worker beryllium exposure above 0.1 ug/m[3].
OSHA recognizes that the available data unequally represent facilities at which more samples were collected, and it seeks additional information to further define the distribution of worker exposure in these industries.
Sector Analysis
The technological feasibility analyses are presented by application groups that correspond to specific industrial sectors or processes as follows:
Section 3 -- Beryllium Production
Section 4 -- Beryllium Oxide Ceramics and Composites
Section 5 -- Nonferrous Foundries
Section 6 -- Secondary Smelting, Refining, and Alloying, Including Handling of Scrap and Recycled Materials
Section 7 -- Precision Turned Products
Section 8 -- Copper Rolling, Drawing, and Extruding
Section 9 -- Fabrication of Beryllium Alloy Products
Section 10 -- Welding
Section 11 -- Dental Laboratories
Additionally, OSHA collected information on three other industries, Primary Aluminum Production, Abrasive Blasting, and Coal-Fired Electric Power Generation. The Agency is considering the inclusion of these industries in the scope of the rule as more information is obtained, and the best available information regarding work practices, exposures and control methods are presented as regulatory alternatives in Appendices A through C of Chapter IV of the PEA.
Within each application group, data are further divided into general job categories representing groups of workers with common trends in materials, work processes, equipment, and available exposure control methods. OSHA notes that these job categories are intended to represent job functions; actual job titles and responsibilities might differ depending on the facility. OSHA recognizes that many other job categories exist in these industries, but those job categories are not associated with substantial direct beryllium exposure and are not included in the analyses.
OSHA seeks additional information that will help identify other job categories that should be addressed in the final rule.
Data Handling
All sample results in the exposure profiles are 8-hour TWA PBZ samples, each collected over a period of at least 360 minutes (defined for this analysis as "full-shift"). To determine an 8-hour TWA, the exposure level for the period sampled is assumed to have continued over any unsampled portion of the shift. OSHA has preliminarily determined that this sample criterion is valid because workers in general industry are likely to work at the same general task or same repeating set of tasks over most of their shift; thus, unsampled periods generally are likely to be similar to the sampled periods.
By setting a minimum sampling period criterion of 6 hours, OSHA ensured that every sample included in the analysis encompasses at least three-quarters of a typical 8-hour shift and probably captures most activities at which the worker spends a substantial amount of time (NIOSH-77-173, 1977). If activities differ during the initial and final portions of the shift, the activities are more likely to involve processes required for initial setup and shutdown, which
generally contribute less to workers' beryllium exposure. OSHA believes the 6-hour (360-minute) minimum sampling requirement limits the extent of uncertainty about workers' true exposure, as no more than 25 percent of an 8-hour shift would be unsampled.
The minimum sampling period also eliminates the ambiguity associated with the LOD for low-air-volume samples. As noted previously in the discussion of LODs, using a common sampling method for beryllium (i.e., sample LOD of 0.013 μg per sample and air sample collected at the recommended rate of 2.0 lpm), an LOD less than 0.018 μg/ m[3] will always be achieved if the sample was obtained for at least 360 minutes. This permits results that are reported in the original data source as below the LOD to be included without contributing substantial uncertainty regarding their relationship to the proposed PEL.
At beryllium concentrations found in many industrial work sites, the smaller air volume obtained using typical methods during a shorter sample period did not collect sufficient beryllium to result in a reading above the LOD. At the same time, the LODs for these shorter duration samples would be higher than they are for 6-hour samples. Using an extreme example, a result of nondetectable for a 15-minute sample (obtained at 2.0 lpm) would have an LOD of 0.43 μg/m[3]. The assigned LOD-based value for that sample would indicate only that the true value was somewhere between 0 and 0.43 μg/m[3], a range too large to be meaningful to OSHA's analysis concerning a proposed PEL of 0.2 μg/m[3]. By relying on 6-hour samples for the exposure profile, OSHA eliminates this ambiguity. OSHA notes that the same 15-minute sample is, however, appropriate for evaluating short-term exposures, and that these provide meaningful information for an analysis of a proposed STEL of 2 μg/m[3].
Particulate Properties and Use in Evaluating Control Options
Ventilation Controls for Airborne Beryllium
Beryllium is a particularly light metal with unique toxicity, strength, and insulating properties. For the purposes of dust management and exposure control, however, airborne beryllium (and its alloys and oxides) behave predictably, like other airborne particles generated and released in a similar manner. Once airborne, the aerodynamic particle size (rather than the particle diameter or its substance) is the fundamental factor that most influences the behavior and choice of control options for particles, including beryllium.
The World Health Organization published an overview of aerodynamic particle size as a fundamental concept in controlling airborne particles of all types, ranging from metals (including beryllium) to minerals (e.g., crystalline silica), bulk chemicals, and biological particles (WHO, 1999):
...In referring to particle size of airborne dust, the term "particle diameter" alone is an over simplification, since the geometric size of a particle does not fully explain how it behaves in its airborne state. Therefore, the most appropriate measure of particle size, for most occupational hygiene situations, is particle aerodynamic diameter, defined as "the diameter of a hypothetical sphere of density 1 g/cm[3] [gram per centimeter] having the same terminal settling velocity in calm air as the particle in question, regardless of its geometric size, shape and true density." The aerodynamic diameter expressed in this way is appropriate because it relates closely to the ability of the particle to penetrate and deposit at different sites of the respiratory tract, as well as to particle transport in aerosol sampling and filtration devices. There are other definitions of particle size, relating, for example, to the behaviour of particles as they move by diffusion or under the influence of electrical forces. But these are generally of secondary importance as far as airborne dust in the workplace is concerned.
      In aerosol science, it is generally accepted that particles with aerodynamic diameter >50 μm do not usually remain airborne very long: they have a terminal velocity >7cm/sec [greater than 7 centimeters per second]. However, depending on the conditions, particles even >100 μm may become (but hardly remain) airborne. Furthermore, dust particles are frequently found with dimensions considerably <1 μm [less than 1 micron] and, for these, settling due to gravity is negligible for all practical purposes. The terminal velocity of a 1-μm particle is about 0.03 mm/sec [millimeters per second], so movement with the air is more important than sedimentation through it. Therefore, summarizing in the present context, it is considered that dusts are solid particles, ranging in size from below 1 μm up to at least 100 μm, which may be or become airborne, depending on their origin, physical characteristics and ambient conditions.
Examples of the types of dust found in the work environment include:
            Mineral dusts, such as those containing free crystalline silica (e.g., as quartz), coal and cement dusts;
            metallic dusts, such as lead, cadmium, nickel, and beryllium dusts;
            other chemical dusts, e.g., many bulk chemicals and pesticides;
            organic and vegetable dusts, such as flour, wood, cotton and tea dusts, pollens;
            biohazards, such as viable particles, moulds and spores.
      Dusts are generated not only by work processes, but may also occur naturally, e.g., pollens, volcanic ashes, and sandstorms. ...The aerodynamic behavior of airborne particles is very important in all areas of measurement and control of dust exposure (WHO, 1999).
In summary, beryllium particles, like other particles, settle out of air at rates related to their aerodynamic diameter. Particles in the range of 100 μm can become airborne when high energy is exerted on them (e.g., when they are "launched" into the air by the energy of a grinding wheel or a broom), but they fall to the ground immediately. Particles between 50 and 100 μm aerodynamic diameter settle more slowly, but still within a few seconds in stationary air. In contrast, smaller particles can stay airborne for hours or days. The behavior of all particles in air is more closely related to the particle aerodynamic diameter than to its other properties. The smaller the particles' aerodynamic diameter, the more easily they are influenced by air motion (i.e., a lower air velocity is required to capture them and carry them away).
Beryllium is a light metal; it has a lower density (mass per volume) than most other metals. A beryllium particle will have a smaller effective aerodynamic diameter compared to otherwise identical particles of a higher density material (e.g., lead, quartz). This means that the lower density beryllium particle will behave consistently with its smaller aerodynamic diameter; in air it will act like a smaller particle than the identical lead or quartz particles. This means that larger beryllium particles may respond more like the smaller respirable dust particles than would identical particles of more dense materials, such as lead. The relationship between density and aerodynamic diameter is demonstrated in Table IV-3.
Table IV-3 -- Aerodynamic Diameters of Particles With Different Densities
                          Particle Stokes Diameter *
                               Relative Density
                           Density of the Particle**
                             Aerodynamic Diameter

                                                                          2 μm
                             Low-density particle
                                   1 g/cm[3]
                                    2.0 μm

                                                                          2 μm
                            Medium-density particle
                                   2 g/cm[3]
                                    2.8 μm

                                                                          2 μm
                             High-density particle
                                   3 g/cm[3]
                                    3.5 μm
*	Stokes diameter takes into consideration the drag force of the particle's surface (rough or smooth) and its shape. In this example, the Stokes diameter is the same, 2 μm, for all three particles; only the density changes.
**	For comparison, the density of beryllium metal is 1.85 g/cm[3]and beryllium oxide is 3.0 g/cm[3]
(see Table IV-4).
Source: USEPA, 2010.

Table IV-4 compares the relative densities of beryllium metal, beryllium oxide, and several other substances. Note that the difference in density between beryllium metal and beryllium oxide is quite modest, and that a mineral (quartz) and another metal (aluminum) fall between the two, suggesting that information on the behavior of beryllium metal and oxide particles could be anticipated by the behavior of quartz and aluminum (in ventilation systems, for example). Similarly, copper and iron are suitable examples for copper-beryllium alloy particle control measures. Even lead is only slightly higher.
Table IV-4 -- Densities of Materials
                                   Material
                                    Density
                                   Reference
Water
                                  1.0 g/cm[3]
                               NIST[a], no date
Beryllium metal, pure
                                  1.8 g/cm[3]
                                 NIST, no date
Quartz, pure (crystalline silica)
                                  2.7 g/cm[3]
                          WI Geological Survey, 2010
Aluminum, pure
                                  2.7 g/cm[3]
NIST, no date
Beryllium oxide
                                  3.0 g/cm[3]
Stefaniak et al., 2007;
Mishima et al., 2006
Chromium (IV) compoundsb
                                2.52-6.12 g/cm3
NIEHSb, 2011
Iron, pure
                                  7.9 g/cm[3]
NIST, no date
Copper-beryllium alloy (Example: 1.9% beryllium; 0.4% nickel + cobalt)
                                  8.3 g/cm[3]
Alloy Wire, no date
Copper, pure
                                  9.0 g/cm[3]
NIST, no date
Lead, pure
                                 10.1 g/cm[3]
NIST, no date
[a]	National Institute of Standards and Technology
[b]	National Institute of Environmental Health Sciences. The range of densities for chromium (IV) compounds represents those most commonly found in industry (i.e., calcium chromate, chromium trioxide, lead chromate, potassium chromate and dichromate, sodium chromate, strontium chromate, and zinc chromate).

In reality, many characteristics influence a particle's aerodynamic diameter and its behavior in a given environment (identical particles only exist in theory); however, density remains one of the most important factors. Other important factors -- particle size and shape -- are results of the action that generated the particle.
The resulting particle size and shape are influenced by both the tool and the amount of energy the tool exerts on the material. Low-speed machining actions often produce material turnings (i.e., shavings) that are too large to remain airborne, while high-speed machining releases very fine particles that do remain airborne. Grinding and crushing (e.g., pulverizing) actions produce particles in a range of sizes, depending on the force, speed, and aggressiveness of the tool action. The finest particles emitted from crushing and grinding equipment may stay airborne. In contrast, the larger particles and chips from these processes, which normally would fall to the ground, can be ejected at high velocity; therefore, the equipment requires special ventilation hoods to capture these larger particles as they are ejected, to avoid dispersing them through the work area. Where metals are heated (e.g., welding and furnace operations), the condensed vapors form small particles that are carried by the rising current of hot air.
Various organizations and investigators group similar particles according to their shape and source. For the purpose of designing suitable ventilation controls, ACGIH places great importance on the nature (in this case related to aerodynamic diameter) of the air contaminant and the action that generates it (ACGIH, 2010). Groupings listed by ACGIH are presented here with examples relevant to beryllium industries:
Fumes and metal smoke: Condensed particles from welding and foundry activities.
Very fine light dusts: Fine particles from beryllium metal and oxide production.
Average industrial dust: Grinding dust, dust from pulverizing and abrasive cutting, general foundry dusts.
Heavy dusts: Metal turnings, foundry tumbling barrels and shakeout, sandblast dust, dust of high-density metals (e.g., lead, copper alloys).
Heavy or moist dusts: Metal dusts with small chips, moist cement (ceramic) dust.
Considering particle sizes and the methods that generate the particles provides OSHA great confidence in using studies of control methods involving other materials and other industries to estimate the effectiveness of control methods for beryllium particles. Several studies have evaluated the size of beryllium particles generated during workplace activities and found that a notable portion of the sample is in the form of respirable particles (particles of aerodynamic diameter 2 μm to 10 μm, centered at 3.5 μm). Examples include the following studies in a beryllium production facility, a copper-beryllium foundry and machining area, machine shops, and an electronics recycling plant.
Kent et al. (2001) reported on mass mean aerodynamic diameter (MMAD) for particles in 55 air samples collected in five different furnace areas at a beryllium manufacturing facility. Overall, three-quarters of the beryllium mass in the samples was associated with particles of MMAD 18 μm or less. Particles of MMAD 10 μm or less (respirable size) contributed more than half (57 percent) of the total beryllium in these samples.