As presented in Table IV-84, 81 percent of the 623 short-term samples measured beryllium levels less than or equal to 2.0 ug/m[3], and 75 percent were less than or equal to 1.0 ug/m[3].  In the most recent time period (2000 to 2008), 77 percent of short-term exposure measurements were less than or equal to 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], and therefore has not reached a preliminary conclusion regarding the technological feasibility of an  alternative STEL of 0.5 ug/m[3].  OSHA preliminarily concludes that the proposed STEL of 2.0 ug/m[3] can be achieved for most operations most of the time, but respiratory protection may be required for a small number of operations for which peak exposures cannot be maintained at or below 2.0 ug/m[3].  However, 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].
Where short-term exposures do remain elevated, even after the proposed PEL has been achieved, a number of control measures are available to reduce short-term worker exposures. The appropriate method depends on the exposure source and generally involves more intensive application of the control measures listed in Appendix B of OSHA's proposed rule and already reported in this analysis.
Until such time as effective controls can be installed, short-term exposure levels (along with the corresponding 8-hour TWA exposure levels) might remain elevated during a few activities, such as powder activities related to the beryllium oxide industry (see Beryllium Oxide Ceramics and Composites Section, 4 of this PEA) and dross handling in the foundry industry (see Section 5 --  Nonferrous Foundries of this PEA).
OSHA believes that there may be some instances in which engineering controls may reduce short-term exposures during these few activities to below the proposed STEL of 2.0 ug/m[3], but not necessarily to below an alternative STEL of 1.0 ug/m[3].  Due to limitations in sample descriptions, as well as the higher detection limit for shorter samples, OSHA cannot characterized the specific conditions under which this may occur.
However, OSHA notes that most of the activities in which short-term exposures may be controlled between 1.0 ug/m[3] and 2.0 ug/m[3] are also the same activities that may occasionally produce short-term exposures above 2.0 ug/m[3] and 8-hour TWA exposures above the proposed PEL.  As such, OSHA estimates that firms that require respirators to control short-term exposures to the proposed STEL can also use these respirators to control exposures to an alternative lower STEL.  This means that the additional costs of compliance when comparing the proposed STEL with an alternative STEL of 1.0 ug/m[3] will be minimal.  Refer to Chapter VIII of the PEA for estimated costs of the regulatory alternatives.
Table IV-85 summarizes short-term exposure levels from OSHA's IMIS database and indicates that, except in the beryllium production industry, short-term exposure levels do not exceed 20 ug/m[3] (10 times the proposed STEL of 2.0 ug/m[3]).  Therefore, a respirator with a maximum use concentration (MUC) of 20 ug/m[3] will offer sufficient protection during these short-term activities.  A respirator with an assigned protection factor (APF) of 10 such as a half-facepiece respirator fitted with P-100 filters will provide this level of protection, although other models, such as a powered air purifying respirator with a loose-fitting hood (APF of 25), or any respirator offering a higher level of protection, will also be suitable. In some cases, as in the beryllium production industry, workers involved with furnace melting and casting, according to Table IV-88, may continue to experience short-term exposures that require a higher level of protection--for example, a full facepiece respirator (APF 50, MUC 100 ug/m[3]) or a powered air-purifying respirator with an APF of 1,000 (MUC 2,000 ug/m[3]). OSHA notes that employers must evaluate both the short-term and 8-hour TWA exposure levels and select respiratory protection that will protect workers from the hazards they might encounter during the work shift.
References
Brush Wellman Inc., 2004. Brush Wellman copper-beryllium machining case study exposure results for three machine shops. Individual sample results provided to Eastern Research Group, Inc., Lexington, MA by Brush Wellman Inc., Cleveland, OH. August.
Corbett, M. L., 2005. Personal communications between Marc L. Corbett (consultant) and Eastern Research Group, Inc.
Corbett, M.L., 2006. Personal  communications between Marc L. Corbett (consultant) and Eastern Research Group, Inc.
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 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 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.
FR 40 (202), 1975. Notice of proposed rulemaking: Beryllium. Federal Register pages 48811- 48827. OSHA Beryllium docket exhibit OSHA-H005C-2006-0870-0350. October 17.
Hands, D., M.J. Sheehan, B. Wong, and H.B. Lick, 1996. Comparison of Metalworking Fluid Mist Exposures from Machining with Different Levels of Machine Enclosure. American Industrial Hygiene Association Journal 57(12): 1173 - 1178. December.
Kent, M.S., 2005. Personal communications between Eastern Research Group, Inc. and Michael S. Kent, Director, Environmental, Health and Safety, Brush Wellman Inc., Elmore, Ohio. January and February.
Kent, M., Corbett M., and Glavin M. 2007. Characterization and analysis of airborne metal exposures among workers recycling cellular phones. 2007 IEE International Symposium on Electronics & the Environment, Orlando, FL (May).
Materion Information Meeting, 2012.  Personal communication during meeting between Materion Corporation and the U.S. Occupational Safety and Health Administration. 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.
Materion SF 201, 2011. Safety Practices for Working with Beryllium Products, SF 201 -- Version 2, March 2011. Materion Brush Inc. Mayfield Heights, Ohio. Available online at: http://materion.com/~/media/Files/PDFs/Corporate/BeSafetyFacts/SF201-SafetyPracticesforWorkingwithBeryllium.pdf.
MBC-A. 2012. Analysis of Population of Exposed to Beryllium. Meeting between Materion Corporation and OSHA. Elmore, OH (May 8-9).
MBC-B. 2010. Industrial Hygiene Evaluation. Meeting between Materion Corporation and OSHA. Elmore, OH (May 8-9).
MBC-C. 2001. Industrial Hygiene Memorandum. Meeting between Materion Corporation and OSHA. Elmore, OH (May 8-9).
MBC-D. 2006-07. Industrial Hygiene Chart. Meeting between Materion Corporation and OSHA. Elmore, OH (May 8-9).
MBC-E. 2008. Industrial Hygiene Memorandum. Meeting between Materion Corporation and OSHA. Elmore, OH (May 8-9).
MBC-F. 2005. Typical Airborne Beryllium Exposures (ug/m[3]) Experienced by CuBe Plastic Mold and Tooling Workers. Meeting between Materion Corporation and OSHA. Elmore, OH (May 8-9). [Supplement to MBCA-G]
MBC-G. 2005. Air and Surface Beryllium Survey. Meeting between Materion Corporation and OSHA. Elmore, OH (May 8-9).
MBC-H. 1991. Industrial Hygiene Evaluation. Meeting between Materion Corporation and OSHA. Elmore, OH (May 8-9).
MBC-I. 2010. Memorandum re Copper Beryllium Exposure Assessment -- Water-jet Cutting. Meeting between Meeting between Materion Corporation and OSHA. Elmore, OH (May 8-9).
MBC-J. 2007. Letter re Copper Beryllium Health and Safety Awareness -- Extrusion Processing. Meeting between Materion Brush Beryllium & Composites and OSHA, Elmore, OH (May 8-9, 2012).
MBC-K. 2000. Industrial Hygiene Evaluation. Meeting between Materion Brush Beryllium & Composites and OSHA, Elmore, OH (May 8-9, 2012).
MBC-L. 2007. Be Exposures >= PEL 2.0 ug/m[3] TWA -- Date Range 2000-2007. Meeting between Materion Brush Beryllium & Composites and OSHA, Elmore, OH (May 8-9, 2012).
MBC-M. 1991. Industrial Hygiene Evaluation. Meeting between Materion Brush Beryllium & Composites and OSHA, Elmore, OH (May 8-9, 2012).
MBC-N. 1991. Industrial Hygiene Evaluation. Meeting between Materion Brush Beryllium & Composites and OSHA, Elmore, OH (May 8-9, 2012).
MBC-O. 1998. Industrial Hygiene Evaluation. Meeting between Materion Brush Beryllium & Composites and OSHA, Elmore, OH (May 8-9, 2012).
MBC-P. 2005. Survey report for characterization and analysis of airborne exposures among workers recycling cellular phones. Meeting between Materion Brush Beryllium & Composites and OSHA, Elmore, OH (May 8-9, 2012).
MBC-Q. 1996. Industrial Hygiene Evaluation. Meeting between Materion Brush Beryllium & Composites and OSHA, Elmore, OH (May 8-9, 2012).
MBC-R. 1993. Industrial Hygiene Evaluation. Meeting between Materion Brush Beryllium & Composites and OSHA, Elmore, OH (May 8-9, 2012).
MC Pkg I-A, 2008. Additional Data  - Water Jet-Cutter: Analytical Report; dated 16 May, 2008. Part A of Information Package I received May 29, 2012, from Materion Corporation by OSHA/DSG/OTF.
MC Pkg I-B, 2008. Occupational Health Aspects of Copper Beryllium Alloy Texturing/Engraving; Presentation made to customer location on the topic of laser engraving; by M.S. Kent, Brush Wellman Inc. on May 28, 2008. Part B of Information Package I received May 29, 2012, from Materion Corporation by OSHA/DSG/OTF.
MC Pkg I-C, 2008. Lapel Air Sample Results for Lasers Area/Laser Engraving Process; dated August 06, 2008. Part C of Information Package I received May 29, 2012, from Materion Corporation by OSHA/DSG/OTF.
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.
MC Pkg I-E-1, 1999. Part 1 (dated August 24, 1999) of 6 Industrial Hygiene Service Reports on machining activities; Part E of Information Package I received May 29, 2012, from Materion Corporation by OSHA/DSG/OTF.
MC Pkg I-E-2, 2001. Part 2 (dated February 12, 2001) of 6 Industrial Hygiene Service Reports on machining activities; Part E of Information Package I received May 29, 2012, from Materion Corporation by OSHA/DSG/OTF.
MC Pkg I-E-3, 2000. Part 3 (dated August 7, 2000) of 6 Industrial Hygiene Service Reports on machining activities; Part E of Information Package I received May 29, 2012, from Materion Corporation by OSHA/DSG/OTF.
MC Pkg I-E-4, 2000. Part 4 (dated September 7, 2000) of 6 Industrial Hygiene Service Reports on machining activities; Part E of Information Package I received May 29, 2012, from Materion Corporation by OSHA/DSG/OTF.
MC Pkg I-E-5, 2000. Part 5 (dated November 14, 2000) of 6 Industrial Hygiene Service Reports on machining activities; Part E of Information Package I received May 29, 2012, from Materion Corporation by OSHA/DSG/OTF.
MC Pkg I-E-6, 2000. Part 6 (dated July 6, 2000) of 6 Industrial Hygiene Service Reports on machining activities; Part E of Information Package I received May 29, 2012, from Materion Corporation by OSHA/DSG/OTF.
MC Pkg I-F, 2000. Industrial Hygiene Survey report dated October 8, 2000, on beryllium/copper extruding process. Part F of Information Package I received May 29, 2012, from Materion Corporation by OSHA/DSG/OTF.
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 ECTB 218-12a, 1997. In-Depth Survey Report: Concentration of Metal Working Mists Before and After Installation of a Commercial Air Cleaner, Sauer-Sundstrand Company, Ames, Iowa. Report No. ECTB 218-12a. U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health. (July 25, 1997)
NIOSH EPHB 263-12a.  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, 2004.
NIOSH EPHB 326-12a, 2008a. Control Technology and Exposure Assessment for Electronic Recycling Operations. Elkton Federal Correctional Institution, Elkton, OH. File No.: EPHB 326-12a, August 2008.
NIOSH EPHB 326-15a, 2008. Control Technology and Exposure Assessment for Electronic Recycling Operations. Unicor Marianna Federal Correctional Institution, Marianna, FL. File N0.: EPHB 326-15a, October.
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 EPHB 326-17a, 2009. Control Technology and Exposure Assessment for Electronic Recycling Operations. United States Penitentiary, Lewisburg, PA. File No.: EPHB 326-17a, January.
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]

SECTION 12 -- Short-Term Exposures, Appendix 1 -- SUPPLEMENTAL ANALYSIS OF NAVY EXPOSURE DATA
Table IV-86 -- Short-Term Beryllium Samples Greater Than 2.0 ug/m[3] and Associated 8-hour TWA Exposure Levels
                                     Year
                                Job Description
                                 Job Category
                                  Short-Term
                                 8-Hour TWA[*]
                                     Note

                                    Minutes
                                    Sampled
                                   ug/m[3]
                                    Minutes
                                    Sampled
                                   ug/m[3]

1988
Casting
Dental appliance, melting/casting
                                      30
                                      3.0
                                      357
                                      3.0
                                       a
1993
Lathing beryllium
Machining
                                      15
                                      3.1
                                      231
                                      0.1
                                     a, b
1995
Grinding Partial [Dental Appliance]
Dental appliance, grinding
                                      15
                                      2.8
                                      375
                                      0.1
                                       b
2000
Grind and polish ticonium [Alloy]
Dental appliance, grinding
                                      15
                                      10
                                      368
                                      1.0

2000
Grind and polish ticonium [alloy]
Dental appliance, grinding
                                      15
                                      2.8
                                      368
                                      1.0

2000
Grinding ticonium [alloy]
Dental appliance, grinding
                                      15
                                      2.8
                                      147
                                     0.07
                                     a, b
2001
Empty grinder dust bag
Equipment repair & maintenance, HVAC
                                      15
                                      4.0
                                      260
                                      0.4
                                       a
[*]	As reported, based on one or more samples. May have been rounded in source document. One 26-minute result of 5.78 ug/m[3] excluded as invalid because the reported 0.17 ug/m[3] 8-hour TWA is not mathematically possible for a shift less than 15 hours.
[a]	Reported 8-hour TWA based on less than 360 minutes total cumulative sample duration.
[b]	The 8-hour TWA is less than the proposed PEL of 0.2 ug/m[3], although the short-term sample result exceeds the proposed STEL of 2.0 ug/m[3].

Source: NEHC, 2003

Table IV-87. Short-Term Beryllium PBZ Exposure Levels Obtained by the U.S. Navy During Various Tasks
                                Job or activity
                                     Total
                                     Count
                                  Nondetected
                                     Count
                                   (Percent)
                    PBZ Beryllium Concentration (ug/m[3])
                           Total Sample Distribution

                                   Total ND
                                      ND
                               > 2.0 ug/m[3]
                                     Mean
                                    Median
                                      Min
                                      Max
                                    <= 2.0
                                   ug/m[3]
                               > 2.0 ug/m[3]
Dental (primarily grinding)
                                      79
                                      70
                                     (87%)
                                       8
                                     (10%)
                                      1.5
                                      1.7
                                      0.1
                                     10.0
                                      66
                                     (84%)
                                      13
                                     (16%)
Equipment repair and maintenance
                                      27
                                      16
                                     (59%)
                                       0
                                     (0%)
                                      0.9
                                      0.3
                                      0.1
                                      5.8
                                      25
                                     (93%)
                                       2
                                     (7%)
Machining
                                      14
                                      13
                                     (93%)
                                       0
                                     (0%)
                                      0.3
                                      0.8
                                      0.2
                                      3.1
                                      13
                                     (93%)
                                       1
                                     (7%)
Aircraft brake work (related to machining)
                                       9
                                       5
                                     (56%)
                                       0
                                     (0%)
                                      1.3
                                      1.4
                                     0.17
                                      3.8
                                       7
                                     (78%)
                                       2
                                     (22%)
Welding/cutting
                                      20
                                      20
                                    (100%)
                                       1
                                     (5%)
                                      1.4
                                      1.0
                                      0.2
                                      3.7
                                      19
                                     (95%)
                                       1
                                     (5%)
Total
                                      149
                                      124
                                     (83%)
                                       9
                                     (6%)
                                      1.3
                                      1.4
                                      0.1
                                     10.0
                                      130
                                     (87%)
                                      19
                                     (13%)
Notes: Beryllium concentrations and distributions presented here are the maximum possible (e.g., the limit of detection value was used for all sample results below the limit of detection); actual values are likely lower because a notable portion of the total short-term sample results are below the limit of detection; however, very few of these exceed 2.0 ug/m[3] and therefore do not unduly influence the results in the range of the proposed STEL.

Source: NEHC, 2003

SECTION 12 -- Short-Term Exposures, Appendix 2 -- IMIS Sample results by industry sectoR AND Job Categories
Table IV-88 -- OSHA IMIS PBZ Total Positive Beryllium Short-Term Air Sampling Results by Industry Sector or SIC Description
                               Application Group
                                 Corresponding
                                  SIC Code(s)
                                   Job Title
                                  No. Samples
                                 No. Positive
                                    Samples
                      Beryllium Concentration (ug/m[3])

                                     Mean
                                    Median
                                      Min
                                      Max
Beryllium Production
                                     3369
Foundry, mold and core preparation
                                       2
                                   2 (100%)
                                     0.75
                                     0.75
                                      0.5
                                      1.0
(Section 3)

Foundry, shakeout
                                       2
                                   2 (100%)
                                      0.4
                                      0.4
                                      0.4
                                      0.4

Furnace, melting and casting
                                      27
                                   27 (100%)
                                     10.4
                                      2.6
                                     0.01
                                      99

Generic, laborer
                                      10
                                   10 (100%)
                                      2.8
                                      0.7
                                      0.3
                                      7.4

Generic, lead man/lead operator
                                      16
                                   16 (100%)
                                      4.7
                                      2.3
                                      0.7
                                      14

Generic, operator
                                      18
                                   18 (100%)
                                     0.49
                                      0.5
                                      0.1
                                      1.1

Generic, other
                                       2
                                   2 (100%)
                                     0.95
                                     0.95
                                      0.7
                                      1.2

Machining, nos
                                       3
                                   3 (100%)
                                     0.43
                                      0.1
                                      0.1
                                      1.1

Pebble plant operator, Be production
                                       6
                                   6 (100%)
                                      1.7
                                      0.7
                                      0.2
                                      4.3

Pelletizing, Be production
                                       2
                                   2 (100%)
                                      0.3
                                      0.3
                                      0.3
                                      0.3

Powdering
                                       2
                                   2 (100%)
                                      2.6
                                      2.6
                                      2.6
                                      2.6

Sheet operator
                                       2
                                   2 (100%)
                                      0.3
                                      0.3
                                      0.3
                                      0.3

Welding and cutting
                                       4
                                   4 (100%)
                                      1.4
                                      1.4
                                      1.2
                                      1.5

TOTAL
                                      96
                                   96 (100%)
                                      4.4
                                      0.7
                                     0.01
                                      99

Beryllium Oxide Ceramics and Composites
                                     3264
No short-term exposure data
                                       0
                                      n/a
                                      n/a
                                      n/a
                                      n/a
                                      n/a
(Section 4)
                                     3651
No short-term exposure data
                                       0
                                      n/a
                                      n/a
                                      n/a
                                      n/a
                                      n/a

                                     3663
No short-term exposure data
                                       0
                                      n/a
                                      n/a
                                      n/a
                                      n/a
                                      n/a

                                     3671
No short-term exposure data
                                       0
                                      n/a
                                      n/a
                                      n/a
                                      n/a
                                      n/a

                                     3674
No short-term exposure data
                                       0
                                      n/a
                                      n/a
                                      n/a
                                      n/a
                                      n/a

                                     3676
No short-term exposure data
                                       0
                                      n/a
                                      n/a
                                      n/a
                                      n/a
                                      n/a

                                     3679
Welding and cutting
                                       3
                                   3 (100%)
                                      0.5
                                      0.4
                                      0.1
                                      1.0

                                     3694
No short-term exposure data
                                       0
                                      n/a
                                      n/a
                                      n/a
                                      n/a
                                      n/a

                                     3714
Racing engine manufacturing
                                       1
                                   1 (100%)
                                     0.26
                                     0.26
                                     0.26
                                     0.26

Welding and cutting
                                       3
                                   3 (100%)
                                      1.0
                                      1.0
                                      0.1
                                      2.0

                                     3845
No short-term exposure data
                                       0
                                      n/a
                                      n/a
                                      n/a
                                      n/a
                                      n/a

TOTAL
                                       7
                                   7 (100%)
                                      0.7
                                      0.4
                                      0.1
                                      2.0

Nonferrous Foundries
                                     3363
Generic, laborer
                                       2
                                   2 (100%)
                                      0.2
                                      0.2
                                      0.2
                                      0.2
(Section 5)
                                     3364
Furnace, melting and casting
                                       6
                                   6 (100%)
                                     0.03
                                     0.02
                                     0.01
                                     0.06

Machining
                                       2
                                   2 (100%)
                                     0.05
                                     0.05
                                     0.05
                                     0.05

                                     3365
Foundry, mold and core preparation
                                       2
                                   2 (100%)
                                      1.3
                                      1.3
                                      0.9
                                      1.7

Foundry, worker
                                      10
                                   10 (100%)
                                      2.5
                                      2.4
                                      0.5
                                      4.3

Furnace, melting and casting
                                       9
                                   9 (100%)
                                      2.6
                                      0.3
                                      0.1
                                      8.8

Machining
                                       4
                                   4 (100%)
                                      0.6
                                      0.6
                                      0.1
                                      1.1

Welding and cutting
                                       1
                                   1 (100%)
                                      0.2
                                      0.2
                                      0.2
                                      0.2

                                     3366
Foundry, shakeout
                                       4
                                   4 (100%)
                                     0.28
                                     0.28
                                     0.05
                                      0.5

Furnace, melting and casting
                                      24
                                   24 (100%)
                                     0.96
                                     0.13
                                     0.03
                                      6.1

Generic, foreman
                                       1
                                   1 (100%)
                                     0.22
                                     0.22
                                     0.22
                                     0.22

Machining
                                       8
                                   8 (100%)
                                     0.16
                                     0.045
                                     0.03
                                      0.5

Metal working, metal chasing
                                       1
                                   1 (100%)
                                      0.2
                                      0.2
                                      0.2
                                      0.2

Unknown tasks, copper foundry
                                       4
                                   4 (100%)
                                     0.22
                                      0.1
                                      0.1
                                      0.6

Welding and cutting
                                       2
                                   2 (100%)
                                      0.1
                                      0.1
                                      0.1
                                      0.1

TOTAL
                                      80
                                   80 (100%)
                                      1.0
                                     0.17
                                     0.01
                                      8.8

Secondary Smelting, Refining, Alloying
                                     3341
Electrical
                                       2
                                   2 (100%)
                                     0.07
                                     0.07
                                     0.07
                                     0.07
(Section 6)

Engineering
                                       1
                                   1 (100%)
                                      0.4
                                      0.4
                                      0.4
                                      0.4

Foundry, foreman
                                       2
                                   2 (100%)
                                     0.02
                                     0.02
                                     0.02
                                     0.02

Foundry, laborer
                                       2
                                   2 (100%)
                                     0.11
                                     0.11
                                     0.11
                                     0.11

Foundry, mold and core preparation
                                       2
                                   2 (100%)
                                      0.6
                                      0.6
                                      0.6
                                      0.6

Foundry, pressing
                                       2
                                   2 (100%)
                                      0.5
                                      0.5
                                      0.5
                                      0.5

Foundry, utility
                                       2
                                   2 (100%)
                                     0.02
                                     0.02
                                     0.02
                                     0.02

Furnace, calcining
                                       1
                                   1 (100%)
                                      3.5
                                      3.5
                                      3.5
                                      3.5

Furnace, charge preparation/charging
                                       9
                                   9 (100%)
                                     0.66
                                      0.7
                                      0.1
                                      1.2

Furnace, incinerator
                                       2
                                   2 (100%)
                                     0.08
                                     0.08
                                     0.08
                                     0.08

Furnace, kiln
                                       2
                                   2 (100%)
                                     0.06
                                     0.06
                                     0.06
                                     0.06

Furnace, melting and casting
                                      67
                                   67 (100%)
                                      3.3
                                      1.8
                                     0.03
                                      18

Furnace, repair and maintenance
                                       4
                                   4 (100%)
                                      1.8
                                      1.8
                                      1.8
                                      1.9

Generic, assistant operator
                                       2
                                   2 (100%)
                                      4.2
                                      4.2
                                      4.2
                                      4.2

Generic, crew leader
                                       2
                                   2 (100%)
                                      1.7
                                      1.7
                                      1.7
                                      1.7

Generic, helper
                                       5
                                   5 (100%)
                                      3.8
                                      1.6
                                      1.3
                                      7.5

Generic, laborer
                                       4
                                   4 (100%)
                                     0.08
                                     0.08
                                     0.06
                                      0.1

Generic, lead operator
                                       2
                                   2 (100%)
                                     0.08
                                     0.08
                                     0.07
                                     0.08

Generic, operator
                                      10
                                   10 (100%)
                                      2.4
                                      3.0
                                     0.07
                                      5.9

Industrial hygiene technician
                                       1
                                   1 (100%)
                                      2.3
                                      2.3
                                      2.3
                                      2.3

Laboratory technician
                                       1
                                   1 (100%)
                                      0.6
                                      0.6
                                      0.6
                                      0.6

                                     3341
Machining
                                       7
                                   7 (100%)
                                      1.0
                                      0.2
                                      0.1
                                      5.1

Maintenance operations
                                       2
                                   2 (100%)
                                      3.1
                                      3.1
                                      0.6
                                      5.5

Material handling
                                       2
                                   2 (100%)
                                     0.11
                                     0.11
                                     0.02
                                      0.2

Mechanical processing
                                      24
                                   24 (100%)
                                     0.64
                                     0.08
                                     0.05
                                      10

Operating equipment, heavy
                                       4
                                   4 (100%)
                                     0.15
                                     0.15
                                      0.1
                                      0.2

Scrap operations
                                       1
                                   1 (100%)
                                      1.7
                                      1.7
                                      1.7
                                      1.7

Shipping/receiving
                                       1
                                   1 (100%)
                                      0.5
                                      0.5
                                      0.5
                                      0.5

Sorting
                                       2
                                   2 (100%)
                                      0.1
                                      0.1
                                      0.1
                                      0.1

Sweeping
                                       1
                                   1 (100%)
                                     14.3
                                     14.3
                                     14.3
                                     14.3

Tool making/grinding
                                       5
                                   5 (100%)
                                     0.34
                                      0.2
                                      0.1
                                      1.0

                                     3399
Coiling
                                       2
                                   2 (100%)
                                      0.1
                                      0.1
                                      0.1
                                      0.1

Furnace, charge preparation/charging
                                       2
                                   2 (100%)
                                      2.3
                                      2.3
                                      2.3
                                      2.3

Furnace, melting and casting
                                       2
                                   2 (100%)
                                      0.7
                                      0.7
                                      0.7
                                      0.7

Generic, lead operator
                                       6
                                   6 (100%)
                                      3.8
                                      4.6
                                      0.6
                                      7.4

Generic, trainee
                                       2
                                   2 (100%)
                                      9.3
                                      9.3
                                      9.3
                                      9.3

Laundry operator
                                       2
                                   2 (100%)
                                      0.1
                                      0.1
                                      0.1
                                      0.1

Machining
                                       2
                                   2 (100%)
                                      2.5
                                      2.5
                                      2.5
                                      2.5

Unknown task, primary metals
                                       2
                                   2 (100%)
                                      0.4
                                      0.4
                                      0.1
                                      0.7

                                     4953
Unknown task, waste processing/disposal
                                       1
                                   1 (100%)
                                      12
                                      12
                                      12
                                      12

TOTAL
                                      194
                                  194 (100%)
                                      2.1
                                      0.6
                                     0.02
                                      18

Precision Turned Products
                                     3451
No short-term exposure data
                                       0
                                      n/a
                                      n/a
                                      n/a
                                      n/a
                                      n/a
(Section 7)
                                     3452
No short-term exposure data
                                       0
                                      n/a
                                      n/a
                                      n/a
                                      n/a
                                      n/a

TOTAL
                                       0
                                      n/a
                                      n/a
                                      n/a
                                      n/a
                                      n/a

Copper Rolling, Drawing, Extruding
                                     3351
Furnace, melting and casting
                                       5
                                   5 (100%)
                                     0.38
                                     0.06
                                     0.01
                                      0.9
(Section 8)

Mechanical processing
                                       2
                                   2 (100%)
                                     0.09
                                     0.09
                                     0.09
                                     0.09

                                     3356
Forging
                                       1
                                   1 (100%)
                                      0.6
                                      0.6
                                      0.6
                                      0.6

Powdering
                                       2
                                   2 (100%)
                                     0.05
                                     0.05
                                     0.05
                                     0.05

                                     3357
No short-term exposure data
                                       0
                                      n/a
                                      n/a
                                      n/a
                                      n/a
                                      n/a

TOTAL
                                      10
                                   10 (100%)
                                     0.28
                                     0.08
                                     0.01
                                      0.9

Fabrication of Beryllium Alloy Products
                                     3469
No short-term exposure data
                                       0
                                      n/a
                                      n/a
                                      n/a
                                      n/a
                                      n/a
(Section 9)
                                     3495
No short-term exposure data
                                       0
                                      n/a
                                      n/a
                                      n/a
                                      n/a
                                      n/a

                                     3678
No short-term exposure data
                                       0
                                      n/a
                                      n/a
                                      n/a
                                      n/a
                                      n/a

TOTAL
                                       0
                                      n/a
                                      n/a
                                      n/a
                                      n/a
                                      n/a

Welding
                                     3089
Welding and cutting
                                       2
                                   2 (100%)
                                     0.01
                                     0.01
                                     0.01
                                     0.01
(Section 10)
                                     3229
Welding and cutting
                                       4
                                   4 (100%)
                                      0.1
                                      0.1
                                      0.1
                                      0.1

                                     3312
Welding and cutting
                                       6
                                   6 (100%)
                                     0.04
                                     0.05
                                     0.005
                                     0.06

                                     3325
Welding and cutting
                                       5
                                   5 (100%)
                                     0.28
                                      0.1
                                      0.1
                                      1.0

                                     3365
Welding and cutting
                                       1
                                   1 (100%)
                                      0.2
                                      0.2
                                      0.2
                                      0.2

                                     3366
Welding and cutting
                                       2
                                   2 (100%)
                                      0.1
                                      0.1
                                      0.1
                                      0.1

                                     3369
Welding and cutting
                                       4
                                   4 (100%)
                                      1.4
                                      1.4
                                      1.2
                                      1.5

                                     3433
Welding and cutting
                                       2
                                   2 (100%)
                                      0.6
                                      0.6
                                      0.6
                                      0.6

                                     3441
Welding and cutting
                                       6
                                   6 (100%)
                                     0.25
                                     0.18
                                     0.06
                                      0.7

                                     3443
Welding and cutting
                                      23
                                   23 (100%)
                                     0.11
                                      0.1
                                     0.01
                                     0.28

                                     3444
Welding and cutting
                                      24
                                   24 (100%)
                                     0.03
                                     0.01
                                     0.01
                                      0.2

                                     3446
Welding and cutting
                                       5
                                   5 (100%)
                                     0.05
                                     0.01
                                     0.01
                                      0.1

                                     3448
Welding and cutting
                                       3
                                   3 (100%)
                                     0.01
                                     0.01
                                     0.01
                                     0.01

                                     3449
Welding and cutting
                                       4
                                   4 (100%)
                                     0.01
                                     0.01
                                     0.01
                                     0.01

                                     3465
Welding and cutting
                                       4
                                   4 (100%)
                                     0.01
                                     0.01
                                     0.01
                                     0.01

                                     3483
Welding and cutting
                                       2
                                   2 (100%)
                                      0.1
                                      0.1
                                      0.1
                                      0.1

                                     3499
Welding and cutting
                                       4
                                   4 (100%)
                                     0.26
                                     0.26
                                     0.05
                                     0.47

                                     3511
Welding and cutting
                                       4
                                   4 (100%)
                                     0.06
                                     0.06
                                     0.03
                                      0.1

                                     3523
Welding and cutting
                                       6
                                   6 (100%)
                                     0.06
                                     0.05
                                     0.04
                                      0.1

                                     3535
Welding and cutting
                                       2
                                   2 (100%)
                                     0.01
                                     0.01
                                     0.01
                                     0.01

                                     3536
Welding and cutting
                                       2
                                   2 (100%)
                                      0.1
                                      0.1
                                      0.1
                                      0.1

                                     3541
Welding and cutting
                                       2
                                   2 (100%)
                                      0.2
                                      0.2
                                      0.2
                                      0.2

                                     3544
Welding and cutting
                                       4
                                   4 (100%)
                                      0.2
                                      0.2
                                      0.2
                                      0.2

                                     3552
Welding and cutting
                                       2
                                   2 (100%)
                                     0.02
                                     0.02
                                     0.02
                                     0.02

                                     3559
Welding and cutting
                                       4
                                   4 (100%)
                                     0.05
                                     0.05
                                     0.05
                                     0.05

                                     3561
Welding and cutting
                                       2
                                   2 (100%)
                                     0.02
                                     0.02
                                     0.02
                                     0.02

                                     3564
Welding and cutting
                                       4
                                   4 (100%)
                                     0.03
                                     0.03
                                     0.02
                                     0.04

                                     3569
Welding and cutting
                                       6
                                   6 (100%)
                                     0.31
                                     0.08
                                     0.05
                                      0.8

                                     3585
Welding and cutting
                                       2
                                   2 (100%)
                                     0.08
                                     0.08
                                     0.08
                                     0.08

                                     3679
Welding and cutting
                                       3
                                   3 (100%)
                                      0.5
                                      0.4
                                      0.1
                                      1.0

                                     3713
Welding and cutting
                                       3
                                   3 (100%)
                                      0.2
                                     0.05
                                     0.05
                                      0.5

                                     3714
Welding and cutting
                                       3
                                   3 (100%)
                                      1.0
                                      1.0
                                      0.1
                                      2.0

                                     3724
Welding and cutting
                                       2
                                   2 (100%)
                                     0.04
                                     0.04
                                     0.04
                                     0.04

                                     3731
Welding and cutting
                                      16
                                   16 (100%)
                                     0.15
                                     0.15
                                     0.06
                                      0.3

                                     3743
Welding and cutting
                                       5
                                   5 (100%)
                                     0.14
                                      0.1
                                      0.1
                                      0.2

                                     3799
Welding and cutting
                                       6
                                   6 (100%)
                                     0.09
                                      0.1
                                     0.07
                                      0.1

                                     3823
Welding and cutting
                                       2
                                   2 (100%)
                                     0.04
                                     0.04
                                     0.04
                                     0.04

                                     3942
Welding and cutting
                                       2
                                   2 (100%)
                                     0.11
                                     0.11
                                     0.11
                                     0.11

                                     3993
Welding and cutting
                                       2
                                   2 (100%)
                                      0.1
                                      0.1
                                      0.1
                                      0.1

                                     5051
Welding and cutting
                                       2
                                   2 (100%)
                                      7.1
                                      7.1
                                      7.1
                                      7.1

                                     5093
Welding and cutting
                                       4
                                   4 (100%)
                                     0.08
                                     0.08
                                     0.08
                                     0.09

                                     7312
Welding and cutting
                                       2
                                   2 (100%)
                                     0.01
                                     0.01
                                     0.01
                                     0.01

                                     7538
Welding and cutting
                                       2
                                   2 (100%)
                                     0.01
                                     0.01
                                     0.01
                                     0.01

                                     7692
Welding and cutting
                                       2
                                   2 (100%)
                                      0.1
                                      0.1
                                      0.1
                                      0.1

                                     7699
Welding and cutting
                                       8
                                   8 (100%)
                                     0.05
                                     0.05
                                     0.02
                                      0.1

TOTAL
                                      209
                                  209 (100%)
                                     0.21
                                     0.07
                                     0.005
                                      7.1

Dental Laboratories
                                     8071
No short-term exposure data
                                       0
                                      n/a
                                      n/a
                                      n/a
                                      n/a
                                      n/a
(Section 11)
                                     8072
Dental, laboratories
                                      10
                                   10 (100%)
                                     0.11
                                      0.1
                                      0.1
                                      0.2

TOTAL
                                      10
                                   10 (100%)
                                     0.11
                                      0.1
                                      0.1
                                      0.2
OVERALL TOTAL FOR ALL INDUSTRIES LISTED

                                      606
                                  606 (100%)

                                       0
                                      99
Notes:
Job categories preceded by the word "unknown" mean there is no job/task description for the sample result or the available information is indiscernible.
There are no SIC codes specific to welding and abrasive blasting; welding and abrasive blasting operations are common throughout the construction and general industry sectors.
Welding exposure data consists of 196 welding sample results that represent welders from general industry SIC that would not otherwise be included in this analysis, plus 13 welding sample results that represent welders from SIC that are in one of the industries addressed in Sections 3 through 11, Beryllium Production through Dental Laboratories, of this PEA (196+13=209). For completeness, those 13 welding samples also appear in this table under the SIC in which those welders actually work. OSHA recognizes that presenting these 13 welding sample under both the welding heading and the individual SIC heading means that the 13 results appear twice in Table IV-88 (the repeat welder samples appear under the headings for SIC 3369, 3679, 3714, and 3366). OSHA believes that the benefit of showing welders in both contexts out ways any minor inconvenience the repetition might cause. The number of individual data points represented in Table IV-88 is 593. Repeating the 13 welder results brings the total number of beryllium exposure results presented in this table to 606.

SIC: Standard Industrial Classification
Be: beryllium
n/a: not applicable
Al/Cu: aluminum/copper
cont: continued
nos: not otherwise specified

Source: OSHA Integrated Management Information System (IMIS) Database, June 1978 through September 2008 (OSHA, 2009). Positive short-term samples (designated as personal breathing zone air samples; STEL, ceiling, or peak)

Chapter IV Appendix A: Primary Aluminum Production
Introduction
Exposure to beryllium can occur during primary aluminum production due to the beryllium content of the crude aluminum ore (bauxite).  Beryllium is found as a naturally occurring impurity in bauxite in varying amounts depending on the source (Taiwo et al., 2008). The average beryllium concentration of bauxite is estimated to be 5 parts per billion (or 0.0000007 percent by weight) (Taylor et al., 2003). During the refining of bauxite into smelting grade alumina, the beryllium contained in bauxite is concentrated in the alumina.  Sources of bauxite with higher levels of beryllium may result in alumina with 1 to 6 parts per million (or 0.0001 percent by weight) of beryllium (Lindsay and Dobbs, 2007).
Process Description
Primary aluminum production begins with the mining of bauxite ore, a heterogeneous material consisting of aluminum hydroxide minerals, aluminosilicates, iron oxide, silica, titanium dioxide and other materials in trace amounts (USGS, 2004). The crude bauxite ore is refined into alumina (aluminum oxide) and then shipped to primary aluminum production establishments for processing into aluminum.
Primary aluminum is produced by the electrolytic reduction of alumina to metallic aluminum (Atkins, 1985). Alumina is added to an electrolytic bath composed of natural or synthetic cryolite and fluoride compounds. The bath is contained in aluminum reduction pots that are 3 to 4 meters (10 to 13 feet) wide and 10 to 12 meters (33 to 40 feet) long and connected in electrical series to form a bank of pots called a potline (Atkins, 1985).
The reduction pots are shallow rectangular steel shells lined with a carbon material. The carbon lining serves as the cathode and consumable carbon electrodes extending into the pot bath serve as the anodes. Electricity is passed from the consumable carbon anodes through the bath causing the alumina to break down or dissociate into aluminum metal and free oxygen (Atkins, 1985). The oxygen reacts with carbon from the anodes to form carbon monoxide and carbon dioxide. Aluminum is deposited at the cathode and remains below the surface of the cryolite bath as molten metal. The temperatures generated by the electric current passing through the pot keeps the bath and precipitated aluminum molten (Karsten, 1982). Additional alumina and bath ingredients are added as needed and molten aluminum is periodically withdrawn (siphoned off) from the pots into tapping crucibles. The molten aluminum is transferred to the casting department where it is cast into aluminum products (alloyed and unalloyed). Some metal may be transported to customers in molten form.
Primary aluminum operations are classified into two types of processes known as prebake and Soderberg. These processes are distinguished by the type of carbon anode used, the method used to introduce the anode into the cell, and the manner in which the pot is worked. In prebake plants, the pots use multiple anodes that are formed and baked in a separate operation prior to consumption in the pots.  Soderberg plants use a single, continuous anode that is shaped and baked in place directly in the pot.  Most of the primary aluminum produced in United States is made using the prebake process.  The prebake process is preferred over the Soderberg process because it generally results in lower ambient emissions (McCawley, 2009).
Affected Job Categories
Beryllium exposure in primary aluminum production is principally associated with pot emissions and potroom support activities (Alcan, 2002, 2003, 2004; Alcoa, 2003; Dion et al., 2005; Labreche et al., 2005; McCawley, 2009; McSherry and Demers, 2004; Noranda, 2004; Thomassen et al., 2005).
The job categories with potential exposures to beryllium include:
Pot tending: During this activity, workers check and adjust the pots to ensure they are running properly. These workers sample the bath and check alumina additions, bath temperatures, electrolyte levels, and anode effects which may cause pot emissions to increase several fold (Atkins, 1985; Sim and Benke, 2003; NIOSH, 1983). These workers are responsible for maintaining optimal conditions in all the pots on the line.  Pots are typically serviced on a daily basis (Atkins, 1985).
Tapping: To tap the pots, workers remove pure aluminum or electrolytic bath from the pots. Tapping is typically conducted at the pot by breaking the crust on top of the bath and vacuum siphoning the molten metal or liquid bath into large crucibles. These crucibles are transported between pots either by crane or specialty vehicles. Typically, every pot is tapped about every 24 hours (Slaugenhaupt and Bruggeman, 2006).
Anode Changing/Setting: Workers break the crust that forms on top of the molten bath, remove spent anodes from the potlines and replace them with new anodes, and adjust the anode bus bar to compensate for the effects of tapping (Sim and Benke, 2003; NIOSH, 1995). Anodes are replaced about once every three weeks (NIOSH, 1983).
Equipment and Material Transport: Typically, workers transport equipment and material by operating overhead cranes. These workers move heavy objects such as crucibles, spent and new anodes, jacking frames, and ore buckets (NIOSH, 1995; Seixas et al., 2000). The removal of spent anodes from pots and the replacement of new anodes is a continually ongoing effort each shift (McCawley, 2009). Other workers operate mobile equipment, such as forklifts and vacuum sweepers, on the potroom floor (McCawley, 2009).
Pot Repair/Lining: Another activity that may expose workers to beryllium is the repair and lining of pots. During the production of aluminum, the pots are filled with a bath of alumina and molten salts.  Over the three to seven year life span of the pot bath, salts migrate into the carbon pot liner, resulting in the deterioration and eventual failure of the utility of the pot as a cathode (e.g., electricity does not flow well enough to maintain necessary production temperatures) (Barnett and Mezner, 1999). When a pot is taken out of service for pot relining, the pot superstructure (steel shell) is dismantled, the solidified pot contents and spent pot liner are broken up to facilitate subsequent handling and disposal, and the pot lining and superstructure are rebuilt (Karsten, 1982; Sim and Benke, 2003).  Pots may be relined in place, or by removing the superstructure and relining the pot outside the potroom (NIOSH, 1983).
Production/Facility Maintenance: Workers also perform regular maintenance on the systems that deliver alumina to the pots, and mechanical and electrical systems (Sim and Benke, 2003).  Other jobs and/or work tasks identified with potential beryllium exposure include sweeping or shoveling loose or spilled bath material near or beneath the pots; removal of solidified electrolyte from used/spent anodes with jack hammers and crow bars (butt cleaning); recycling activities associated with spent pot liner material; and air pollution equipment maintenance (Alcoa, 2003; Dion et al., 2005; McCawley, 2009; McSherry and Demers, 2004).
Exposure Data
Air monitoring to assess exposure to beryllium was conducted at four primary aluminum smelters (one in the U.S., two in Canada, and one in Italy) between 2000 and 2005 (Taiwo et al., 2008).  The results of the air samples are presented in Table IV.A-1.  The geometric mean exposure at the four smelters ranged from 0.03 to 0.10 ug/m[3], indicating that the majority of exposures are below 0.1 ug/m[3].   For all four smelters combined, 75% of the measurements were less than 0.16 ug/m[3].
Table IV.A-1 -- Distribution of Beryllium Exposures at Four Aluminum Smelters

                         Exposure Summary  (ug/m[3])
             Distribution of Be Exposure by Percentile (ug/m[3])
                                    Smelter
                                       N
                                      AM
                                      SD
                                      GM
                                      GSD
                                      25%
                                      50%
                                      75%
                                      95%
                                   Max-imum
US Smelter
                                      346
                                     0.26
                                     0.85
                                     0.04
                                     5.66
                                     0.02
                                     0.03
                                     0.09
                                     1.50
                                     12.00
Canadian Smelter 1
                                      246
                                     0.09
                                     0.21
                                     0.03
                                     3.62
                                     0.01
                                     0.03
                                     0.07
                                     0.33
                                     2.02
Canadian Smelter 2
                                      329
                                     0.29
                                     0.82
                                     0.08
                                     5.87
                                     0.05
                                     0.11
                                     0.26
                                     1.70
                                     13.00
Italian Smelter
                                      44
                                     0.14
                                     0.10
                                     0.10
                                     2.55
                                     0.06
                                     0.12
                                     0.19
                                     0.31
                                     0.44
All 4 combined
                                      965
                                     0.22
                                     0.71
                                     0.05
                                     4.67
                                     0.02
                                     0.05
                                     0.16
                                     1.20
                                     13.00
Source: Taiwo et al., 2008

The results of air monitoring conducted to assess exposures to beryllium at six Norwegian aluminum smelters were reported by Skaugset et al (2012).  Table IV.A-2 provides the results of sampling conducted in 2003 and 2004.  The geometric mean of the air samples taken to assess exposure to respirable beryllium was very low (0.005 ug/m[3]); however, the maximum values exceeded 0.2 ug/m[3]. At one of the smelters, air sampling was conducted both before and after installation of an "enforced cell ventilation system" in the potroom.  The sampling results indicate that the geometric mean exposure to inhalable beryllium in the potroom was reduced following installation of the ventilation system from 0.112 ug/m[3] to 0.041 ug/m[3], a reduction of 63%.
Table IV.A-2 -- Beryllium Air Sampling Results at Six Norwegian Smelters
                                No. of Samples
                           Geometric Mean (ug/m[3])
                               Range (ug/m[3])
                                      247
                                     0.005
                                <0.005-0.236
Source: Skaugset et al., 2012

Based on the sampling data presented in Table IV.A-1, which represents the largest data pool for exposures in US primary aluminum smelters, OSHA estimates that less than 30 percent of the potroom workers in primary aluminum production may be exposed to beryllium levels at or above 0.1 ug/m[3], and that less than 20% of potroom workers may be exposed to levels above the proposed PEL of 0.2 ug/m[3]. OSHA notes that the maximum values reported exceeded the proposed PEL.
OSHA obtained unpublished data from McCawley, 2009. with individual PBZ air sampling results for prebake and Soderberg operations at an Alcoa Canadian smelter. This is the only information available to OSHA regarding exposure results associated with specific job tasks at aluminum smelters. Table IV.A-3 indicates that workers in potrooms and those engaged in maintenance activities could be exposed to beryllium exposures above the proposed PEL.  To the extent that exposures exceed the proposed PEL, OSHA has identified engineering controls that can minimize exposures to these workers.
Table IV.A-3 -- Full-Shift PBZ Total Beryllium Air Sampling Results at a Canadian Smelter
                                    Process
                                      Job
                                     Task
                            Total Be Concentration
                                  (ug/m[3])
Prebake
Crane Operator
Anode changing
                                     0.19
Prebake
Line Attendant
Operating mobile equipment on potroom floor
                                     0.28
Prebake
Butt cleaner
Cleaning spent anodes
                                      ND
Prebake
Pot Tender (process control)
Sampling metal, bath, and temperature
                                     0.37
Prebake
Bagger
Bagging powder (ground spent bath material)
                                      ND
Soderberg
Tapper
Cleaning tapping equipment
                                     0.17
Soderberg
Tapper
Tapping metal on potroom floor
                                     0.20
Soderberg
Line Attendant
Operating mobile equipment on potroom floor
                                      ND
Soderberg
Pot Tender (process control)
Pulverizing a sample
                                      ND
Soderberg
Services Operator (near pots)
Sweeping/shoveling loose/spilled bath material
                                     0.10
Soderberg
Services Operator (beneath pots)
Cleaning the basement
                                     0.39
ND: non-detectable.  Beryllium less than the limit of quantitation (0.1 micrograms of beryllium per filter).

Source: McCawley, 2009

DESCRIPTION of Engineering Controls
Baseline Controls
All primary aluminum production facilities in the United States capture and control process emissions at the source (EPA, 1996). While these controls are not specific to the control of beryllium exposures, they are relevant because they are applied at the same sources of beryllium exposure. Potroom buildings are typically ventilated by general dilution. Pot emissions are controlled by totally enclosing, sealing, and exhausting the pot to a central emission collection and treatment system. Periodically, the pots are opened to add raw materials, replace anodes, correct anode effects, and to remove molten aluminum. These tasks require personnel to remove some of the hooding (anode covers) and be in close proximity to the pot emissions.
OSHA believes that some of the cranes and forklifts used for material and equipment transport are equipped with air-conditioned and air-filtered cabs.  NIOSH (1983) reported that operators of manned equipment sit in enclosed, conditioned, and filtered-air cabs that can provide significant protection from process-related emissions.
Additionally, establishments may use automated processes to make aluminum.  OSHA believes that some establishments may use computer-controlled equipment and systems that automatically perform crust breaking and ore additions, and eliminate anode effects.
Some of the primary aluminum producers in the United States may employ personal protective equipment (PPE).  Information from smelters in Canada and Norway state that workers at those plants use PPE such as work uniforms, respirators, and head, eye and foot protection (AIHABC, 2004; Dion et al., 2005; Labreche, 2005; McSherry and Demers, 2004; McSherry, 2005; Noranda, 2000; Thomassen et al., 2005).  Other U.S. aluminum producing establishments may not use PPE (Labreche, 2005).
Other Engineering Controls
High short-term exposures to pot emissions may be a hazard for workers when the pot hooding (individual removable shields or doors that comprise the pot local exhaust ventilation (LEV) system) is periodically removed to add raw materials, replace anodes, correct anode effects and remove molten aluminum (Sim and Benke, 2003).  Opening the pot hooding reduces the velocity of the exhaust ventilation allowing beryllium and other air contaminants to escape into the workplace.
Local Exhaust Ventilation
OSHA estimates that all potrooms employ LEV at individual production pots. Available information suggests that LEV can be improved to reduce process emissions (EPA, 1996).  Enhanced ventilation designed for production pots will reduce exposures during pot tending and tapping, and during anode changing and setting.
The ventilated enclosure for pots consists of a structure with side shields and end doors.  Many plants can increase the exhaust rate on a pot when one or more of the side shields are removed; thus reducing the amount of process emissions escaping into the workplace.  Typical exhaust rates for larger pots are reported to range from 3,000 to 4,900 cubic feet per minute (cfm) per pot.  When needed, most plants with larger pots can increase the exhaust rate up to 50 percent over the normal rate.  The exhaust rates for smaller and older pots range from 2,000 to 2,250 cfm per pot and there might be very limited ability to increase this rate, perhaps only by as much as 15 percent maximum when feasible (EPA, 1996).
Regardless of how well the pots are enclosed and sealed, workers may need to open and/or remove side shields or end doors to work the pots, replace anodes, correct anode effects, make inspections, measure the depth of aluminum, and tap metal.  To control process emissions and potential worker exposure, potline hooding must be carefully designed, constructed, and maintained; and potroom operators must not open or remove shields more frequently than is absolutely necessary.  The number of hoods or shields that are open, the extent to which they are open, and the duration affect the efficiency of the hooding and the release of process emissions into the workplace.  To control the escape of process emissions, many plants limit the number of side shields and end doors that can be open at any one time. Other potline exposure control measures practiced at some plants include increasing the exhaust rate on open pots and exhausting tapping emissions back into the primary hooding (EPA, 1996).
LEV may also be used during pot repair and demolition.  These activities are typically conducted with the use of jackhammers, which can be equipped with LEV to reduce the concentration of airborne particles.  To illustrate the capacity of LEV to reduce exposures, OSHA notes that NIOSH tested two tool-mounted LEV shrouds: one custom built, the other a commercially available model during work with chipping hammers (intended for chipping vertical concrete surfaces).  Comparing multiple short - term samples, NIOSH found that the shrouds reduced respirable dust by 48 to 60 percent (Echt et al., 2003; NIOSH EPHB 282-11a, 2003).  In a separate evaluation, NIOSH evaluated short-term activities in which workers used 25- or 30-pound jackhammers to chip concrete from inside concrete mixer truck drums. During 90- to 120-minute periods of active chipping, mean silica levels decreased 69 percent when the workers used a tool-mounted LEV shroud in these enclosed spaces (NIOSH EPHB 247-19, 2001).  Based on these studies, OSHA believes that similar reductions can be achieved during pot demolition as the LEV would control total dust generated, which would include beryllium dust.
Process Automation
Automating (mechanization and computer control) crust breaking and pot feeding results in lower pot temperatures, fewer and shorter anode effects, and reduced pot emissions when compared to manual operation because pot operators have more time to closely monitor the pots and maintain temperature within narrow ranges.  Automation of the process also reduces the need to open hooding components (e.g., to add chemicals, correct overfeeding problems or anode effects) which reduces the amount of emissions that escape into the workplace and potential worker exposure to beryllium and other air contaminants in these emissions.  Automation in the potroom will reduce overall exposures, especially during pot tending and tapping, and anode changing and setting (EPA, 1996).
When a potline is completely automated, the operating parameters of each pot are monitored on a regular basis and any variation from the normal set operating parameters is automatically corrected. Additionally, with complete automation, all pots in a potline can be operated at the lowest possible temperature, with fewer process upsets, and essentially none of the variability associated with operator work practices (EPA, 1996).
Some examples of process automation in the potroom include the use of specially designed equipment (e.g., cranes and pot tending machines) for changing anodes and tapping metal.  Manned cranes can be equipped with a pneumatically operated punch for breaking the crust around the anode to be removed, an arm for anode removal and placement, a dual-wrench for anode-to-bus connections, and a feed spout and storage bin for the alumina used to cover a newly placed anode.  Other cranes are computer controlled and automatically make ore additions, do crust breaking, and eliminate anode effects (EPA, 1996).
Enclosed Cabs for Material and Equipment Transport
Enclosed operator cabs on forklifts and cranes can help reduce beryllium exposure for material handlers. As mentioned in Chapter IV, Technological Feasibility, of the Preliminary Economic Flexibility Analysis (PEA), enclosed cabs can substantially reduce exposures to beryllium dust and fumes. OSHA estimates that enclosed cabs can achieve a 90 percent reduction in beryllium exposures. See Chapter IV.5 of the PEA (Nonferrous Foundries) for details on some of the studies that discuss beryllium particle sizes in smelting environments and the reductions achieved with enclosed cabs.
Since workers engaged in material and equipment transport do not work directly at the main source of exposure (i.e., pots), OSHA believes that enclosed cabs will maintain exposures to these workers below the proposed PEL during transport.  To the extent that these workers are not working on transport, LEV at the pots will also help maintain their exposures at a minimum.
Wet methods
During pot repair and demolition, OSHA believes that jackhammers equipped with water delivery systems would effectively suppress dust generated and thus control exposures to beryllium.
NIOSH completed several studies evaluating water spray devices to suppress dust created while workers use chipping and breaking equipment (NIOSH EPHB 282-11a, 2003). NIOSH investigated water spray dust control used by workers breaking concrete with 60- and 90-pound jackhammers. Using both a direct reading instrument and a high-flow cyclone and filter, NIOSH collected 10-minute respirable dust readings with and without the spray activated. Compared with concentrations during uncontrolled pavement breaking, respirable dust results were between 72 and 90 percent lower when the water spray was used. A follow-up NIOSH study reported a similar 77 percent reduction in silica concentration during 60-minute trials (NIOSH EPHB 282-11c-2, 2004).
OSHA believes that wet methods may also be used during removal of solidified electrolyte from used/spent anodes. OSHA expects that the grinders used for this task, when equipped with water delivery systems, can achieve significant dust reductions as mentioned by the NIOSH studies above.  Additionally, shoveling loose or spilled bath material around pots should be conducted with a dust suppression method such as water to minimize the amount of dust that may become airborne.
The available information about the aluminum production process indicates that peak exposures can occur during short term tasks.  When LEV or wet methods are not sufficient to control exposures during pot repair and dismantling, respirators would further protect workers. Respirators may also be necessary to protect workers during tapping and anode changing and setting. Employers should be especially cautious about minimizing anode effects as these increase process emissions and exposures to beryllium.  Also, as workers tend the pots, LEV hooding is lifted, and the exhaust system loses capture efficiency.  Respirators would also further protect workers during maintenance activities such as regular maintenance on the systems that deliver alumina to the pots, and mechanical and electrical systems, and during recycling activities associated with spent pot liner material and air pollution equipment maintenance.
References
Alcan, 2002.  Beryllium and Health.  Alcan in Quebec.  2002 Social Responsibility: A Balance Sheet Report.  Committed people taking sustainable action.  Alcan Incorporated, Montreal, Quebec, Canada.
Alcan, 2003.  Beryllium and Health.  Alcan in Quebec.  2003 Social Responsibility -- A Balance Sheet Report.  Moving Towards a Sustainable Future.  Alcan Incorporated, Montreal, Quebec, Canada.
Alcan, 2004.  The risk of beryllium.  Alcan in Quebec.  2004 Social Responsibility -- A Balance Sheet Report.  Working Hard To Achieve Sustainability.  Alcan Incorporated, Montreal, Quebec, Canada.
Alcoa, 2003.  Beryllium Expertise and Action.  Life Magazine -- Alcoa Canada Primary Metals 2003.  Alcoa Canada Primary Metals, Montreal, Quebec.
Atkins, P.R., 1985.  Primary Aluminum Smelting.  Industrial Hygiene Aspects of Plant Operations: Volume 3, Engineering Considerations in Equipment Selection, Layout, and Building Design.  Edited by Lester V. Cralley, Lewis J. Cralley, and Knowlton J. Caplan.  New York: Macmillan Publishing Company.
Barnett, R.J. and M.B. Mezner, 1999.  Method of Treating Spent Potliner Material from Aluminum Reduction Cells, United States Patent 5955042.
Dion, C., A. Dufresne, Y. Cloutier, G. Perrault, and S. Viau, 2005.  Exploring Determinant Factors for Beryllium Exposure Assessment in Occupational Setting.  Paper presented at the 2005 International Beryllium Research Conference, Montreal, Quebec, Canada. March 8 - 11.
Echt, A., K. Seiber, E. Jones, D. Schill, D. Lefkowitz, J. Sugar, and K. Hoffner, 2003. Control of respirable dust and crystalline silica from breaking concrete with a jackhammer. Applied Occupational and Environmental Hygiene 18:491-495.
EPA, 1996.  Primary Aluminum Industry: Technical Support Document for Proposed MACT Standards.  U.S. Environmental Protection Agency.  Office of Air Quality Planning and Standards.  Emission Standards Division.  July.
Karsten, K.P., 1982.  Aluminum.  Industrial Hygiene Aspects of Plant Operations, Volume 1, Process Flows.  Edited by Lester V. Cralley and Lewis J. Cralley.  New York: Macmillan Publishing Company.
Labreche, F., J. Forest, and C. Lafortune, 2005.  Identification of Beryllium Exposures in Primary Metal Industries and Aeronautics Plant Operating a Foundry: The Quebec Experience.  Paper presented at the 2005 International Beryllium Research Conference, Montreal, Canada, March 8 - 11.
Lindsay, S.J. and C.L. Dobbs, 2007.  Beryllium in Pot Room Bath.  Paper presented at the Third International Conference on Beryllium Disease, Philadelphia, Pennsylvania.  October 16 - 19.
McCawley, 2009 (Unpublished Article).  Regarding attachment:
McCawley, M., C.L. Dobbs, and H.M. Cole. Beryllium Exposure Characterization in Soderberg and Prebake Aluminum Potrooms. [Draft manuscript].
McSherry, A. and P. Demers, 2004.  Assessment of Beryllium and Total Particulate Exposure at Alcan Kitimat Works Aluminum Smelter.  Graduate Student Poster Session Abstract. Poster Session 405, Abstract 23.  2004 American Industrial Hygiene Conference and Exposition (AIHCE).  Georgia World Congress Center, Atlanta, Georgia.  May 8 - 13.
NIOSH, 1983.  Occupational Health Control Technology For The Primary Aluminum Industry. U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control, National Institute for Occupational Safety and Health, Division of Physical Sciences and Engineering, Cincinnati, Ohio.  DHHS (NIOSH) Publication No. 83-115.  June.
NIOSH, 1995.  Health Hazard Evaluation Report.  Kaiser Aluminum, Mead, Washington.  U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control, National Institute for Occupational Safety and Health.  HETA 95-0092-2545. December.
NIOSH EPHB 282-11a. National Institute for Occupational Safety and Health, 2003. In-depth survey report of control of respirable dust and crystalline silica from breaking concrete with a jackhammer at Bishop Sanzari companies, North Bergen, New Jersey.
NIOSH EPHB 282-11c-2. National Institute for Occupational Safety and Health, 2004. In-depth survey report of a water spray device for suppressing respirable and crystalline silica dust from jackhammers.
NIOSH EPHB 247-19. National Institute for Occupational Safety and Health, 2001. Control technology for ready-mix truck drum cleaning.
Noranda, 2000.  Sustainable Development Report 2000.  Fulfilling Our Commitments.  Noranda, Inc., Toronto, Ontario, Canada.
Noranda, 2004.  Noranda, Inc./Falconbridge Limited 2004 Sustainable Development Report. Meeting the Challenge.  Noranda, Inc., Toronto, Ontario, Canada.
Seixas, N.S., M. Cohen, B. Zevenbergen, M. Cotey, S. Carter, and J. Kaufman, 2000.  Urinary Fluoride as an Exposure Index in Aluminum Smelting.  American Industrial Hygiene Association Journal 61: 89-94.  January/February.
Sim, M. and G. Benke, 2003.  World at Work: Hazards and Controls in Aluminum Potrooms.  Occupational and Environmental Medicine 60 (12): 989-992.
Skaugset, N.L., Ellingsen, D.G., Dahl, K., Martinsen, I., Jordbekken, L., Drables, P.A., and Thomassen, Y., 2012.  Occupational exposure to beryllium in primary aluminium production.  Journal of Environmental Monitoring 14:  353-359.
Slaugenhaupt, M.L. and J.N. Bruggeman, 2006.  Measuring Duct Offgas Temperatures to Improve Electrolytic Cell Energy Efficiency.  United States Patent 7112269.
Taiwo, O.A., M.D. Slade, L.F. Cantley, M.G. Fiellin, J.C. Wesdock, F.J. Bayer, and M.R. Cullen, 2008.  Beryllium Sensitization in Aluminum Smelter Workers.  Journal of Occupational and Environmental Medicine 50 (2): 157-162.
Taylor, T.P, M. Ding, D.S. Ehler, T.M. Foreman, J.P.Kaszuba, and N.N. Sauer, 2003.  Beryllium in the Environment: A Review.  Journal of Environmental Science and Health, Part A -- Toxic/Hazardous Substances and Environmental Engineering A38 (2): 439-469.  Cited by Hormann, P.K.: Beryllium.  In Handbook of Geochemistry, Wedepohl, K.H., Editor. New York: Springer-Verlag, 1969, II/1, 4D1-4O7.
Thomassen, Y., D.G. Ellingsen, K. Dahl, I. Martinsen, N.P. Skaugset, and P.A. Drablos, 2005. Occupational Beryllium Exposure in Primary Aluminum Production.  Paper presented at the 2005 International Beryllium Research Conference, Montreal, Quebec, Canada.  March 8 - 11.
USGS, 2004.  Bauxite and Alumina.  Minerals Yearbook.  2004.  Volume I: Metals and Minerals.  U.S. Department of the Interior.  U.S. Geological Survey.

Chapter IV -- Appendix B: Coal-Fired Electric Power Generation
Introduction
The potential for exposure to beryllium at coal-fired electric power plants is associated with the naturally occurring beryllium content of coal and fly ash.  In a 1987 public health assessment document for beryllium, the average beryllium concentration in coal was reported to vary between 1.8 and 2.2 micrograms per gram of coal (ug/g) (EPA, 1987).  Clarke and Sloss (1992) report that the typical beryllium concentration of coal is 2 ug/g and ranges from 0.1 to 15 ug/g.  The West Virginia Geological and Economic Survey reports that beryllium concentrations in West Virginia coal based on 851 analyses range from 0.007 ppm to 24.72 ppm with an average of 2.57 ppm (WVGES, 2002).  In a review of beryllium in the environment, Taylor et al. (2003) report that the beryllium concentration in U.S. coal typically ranges from 1.46 to 1.52 ppm.  Beryllium concentrations in the coals of 28 U.S. states range from 0.18 to 3.17 ppm.
Fly ash is fine particulate formed by the combustion of coal.  The composition of coal fly ash varies depending on the type of coal, preparation techniques (such as cleaning and crushing) prior to burning, and boiler operating conditions.  Fly ash is primarily comprised of silicon, aluminum, iron, and calcium oxides with magnesium, potassium, sodium, titanium, and a wide range of trace elements (including beryllium).  One source reports that in the United States fly ash contains on average 46 milligrams of beryllium per kilogram of ash (Stadnichenko et al., 1961).  More recent investigations at coal-fired power plants report beryllium concentrations in fly ash and settled dust ranging from 0.4 ppm to 10 ppm depending on sample location (NIOSH, 1996, 1997).  Bulk samples of fly ash, bottom ash, and lignite coal collected during a National Institute for Occupational Safety and Health (NIOSH) health hazard evaluation (HHE) at one large coal-fired power plant contained 4 ppm, 2 ppm, and nondetectable levels of beryllium, respectively (NIOSH, 1996a).[,]
Fly ash also consists of other heavy metals which are regulated by OSHA.  Most notably arsenic (29 CFR 1910.1018) in which arsenic is often in concentrations 10 to 1000 times greater than beryllium.  OSHA currently regulates exposures to arsenic in power plants due to the fact that arsenic is contained in fly ash (see OSHA-H054A-2006-0064-1972).

Process Description
The electric power generation industry includes facilities that use coal, petroleum, gas or other fossil fuels (as opposed to solar, thermal, hydro, or nuclear energy) to generate electricity.  Approximately 80 percent of the coal produced annually in United States is used to generate electric power and nearly half of the nation's electricity comes from coal (Kim and Kazonich, 1999; EEI, 2010).
Coal-fired steam turbine generation includes 1) a heating system, 2) a boiler and steam delivery system, 3) a steam turbine, and 4) a condenser for condensation of used steam.  Pulverized or crushed coal (fuel) is pumped into the boiler's furnace and combusted.  Heat from the combustion process generates steam.  High temperature, high pressure steam from the boiler enters the steam turbine, drives the turbine blades, and powers the electric generator.  Low-pressure steam exits the turbine, enters the condenser where it is cooled to condensate, and then is transported (by the boiler feedwater system) back to the boiler where it is reused.
Coal is transported to the plants by rail, truck, or barge and is unloaded to live storage, dead storage, or directly to the hopper or stoker.  Coal unloading techniques vary depending on the type and size of plant.  Live storage refers to an enclosed bunker or silo that is adjacent to conveyors leading to the pulverizer.  Dead storage is the backup supply of coal and is stored outdoors in the open.  From the coal bunker or silo, coal is transported to pulverizers, cyclones, or stokers to crush, grind, and dry the coal.
To control the dust associated with coal handling (e.g., unloading, storage, and processing), dust suppression may be required, especially in dry climates and during warmer weather.  Water, oil, and calcium chloride (CaCl2) are typically used for dust suppression.  During the winter months, antifreeze chemicals are applied to coal.  Coal may also be cleaned to reduce dust emissions and coal impurities such as metals, ash, silica, and sulfur.  Coal cleaning is typically performed at the mine using a variety of methods.  Some utility plants purchase pre-cleaned coal that significantly reduces the amount of dust generated during coal unloading.  After the coal is ground and dried, it is transported to the boiler for combustion.
Waste from the combustion process includes fly ash (fine airborne particles that result from the burning of coal), bottom ash, boiler slag, and exhaust gases.  Fly ash and exhaust gases typically pass through air cleaning devices before exiting the exhaust stack.  Bottom ash consists of large agglomerated ash particles that adhere to the boiler walls or fall through open grates to an ash hopper at the bottom of the boiler.  Boiler slag is molten ash that is quenched with water and breaks into black, angular particles with a smooth, glassy appearance.  Boiler slag is collected at the base of slag tap and cyclone boilers.  The main components of coal fly ash are oxides of silicon, aluminum, iron, and calcium, with lesser amounts of magnesium, sulfur, sodium, and potassium.  Other metals can be found in trace quantities: arsenic, cadmium, beryllium, thallium, nickel, lead, manganese, chromium, selenium, zinc, and other metals.
Affected Job Categories
Workers in coal-fired electric power plants with potential exposure to airborne contaminants may be broadly categorized as operations workers and maintenance workers (including baghouse cleaners and coal handling personnel) (NIOSH, 1981).  Table IV.B-1 summarizes the tasks and/or job titles associated with these work categories.

Table IV.B-1 -- Workers in Coal-Fired Power Plants with Potential Exposure to
Airborne Contaminants (NAICS 221112)
Job Category
Description
Operations
Operations workers operate, control, and monitor the routine production of electric power.  Work tasks may include operating, testing, and inspecting equipment and processes, observing and recording equipment operation parameters, and others.  Most of the work shift may be spent inside an air-conditioned control room under positive pressure.  Several times a shift these workers conduct walk-through surveys of the entire facility to monitor the operation.  Job titles include control and auxiliary (equipment) operator, boiler and assistant boiler turbine operator, fireman, tender, helper and auxiliary helper, and others.
Maintenance
Maintenance workers are responsible for the routine upkeep of the facility as well as emergency repairs.  Examples of routine maintenance include regular inspection and maintenance of pulverizers, soot blowers, fans, and meters/gauges.  Examples of scheduled outage (shut downs) maintenance include boiler inspection and repair and hopper maintenance.  Job titles include maintenance mechanic, maintenance worker, mechanic, apprentice mechanic, instrument technician, instrument and control repair worker, electrician, apprentice electrician, electric technician, welder, custodian, janitor, and others.
Baghouse/ESP cleaners
Baghouse/ESP cleaners service and maintain air cleaning devices during scheduled outages (e.g., baghouse changeout or high efficiency cleaning; ESP inspection, cleanout, and wash; shoveling fly ash dust from ESP shelves).  Some power plants hire traveling contract work crews to perform baghouse/ESP service and maintenance.
Coal Handlers
Coal handlers are involved with coal handling activities in the coal yard as well as inside the power plant.  Job titles include coal handler, coal equipment operator, switchman/sampler, unloader, train or locomotive operator, tractor operator, car runner, conveyor man, tripper deck operator, and others.
ESP: Electrostatic precipitator

Source: NIOSH, 1981, 1988; Bird et al., 2004; Beaulieu et al., 2006

Coal-fired electric power plants might operate under routine conditions about 60 to 70 percent of the time (Bird et al., 2004).  The remaining time is associated with scheduled and unscheduled (e.g., unforeseen equipment failures) shut downs or outages.  Scheduled outages typically involve some form of preventive maintenance and include disassembly, inspection, repair/rebuilding, and reassembly of plant equipment such as boilers and steam turbines.  Baghouse maintenance has been associated with high levels of exposure to fly ash.
Exposure Data
Beryllium exposure to workers at coal-fired electric power plant was monitored during three NIOSH HHEs  (NIOSH 1988, 1996, 1997).
NIOSH -- City of Ames Municipal Power Plant (NIOSH, 1988)
On July 21 - 23, 1986 and January 12 - 14, 1987, a NIOSH health hazard evaluation was conducted at the City of Ames, Iowa, municipally-owned coal and refuse derived fuel (RDF) power plant during what are described as routine, non-outage work activities.  NIOSH investigators conducted an initial walkthrough survey of the process on July 21 - 23 and collected bulk samples of settled dust and insulation at various locations throughout the plant to use in developing a follow-up monitoring protocol.  The bulk samples were analyzed for trace or minute amounts (e.g., 0.1 percent or less) of metals using NIOSH Method 7300 (ICP/AES) and the sample limit of detection (LOD) for beryllium was reported to be 1.0 microgram per gram of sample (0.0001 percent).  NIOSH investigators reported that beryllium and other toxic metals were present in 50 percent or more of the bulk settled dust samples.
During the follow-up survey on January 12 - 14, personal breathing zone (PBZ) monitoring was conducted for various air contaminants including trace metals identified in the bulk samples of settled dust.  A total of 15 PBZ samples for trace metals were collected on operations and maintenance workers during presumed routine, non-outage work activities.  All samples were full-shift except for one shorter duration sample (collected on a maintenance worker present for a partial shift).  The samples were analyzed using NIOSH Method 7300 with a limit of quantitation (LOQ) for beryllium of 1.0 ug/sample. Worker exposures to all metals including beryllium were nondetectable.  Based on the reported LOQ, these samples indicate that beryllium exposures were below 1.0 ug/m[3].  However, the beryllium content of the dust at this facility was less than 0.01%, and respirable dust samples collected on operations workers at this facility ranged from 0.3 to 3.6 mg/m[3].  When multiplied by the detection limit of 0.01%, OSHA estimates that beryllium exposures were most likely less than 0.03 to 0.36 ug/m[3].
NIOSH -- Bruce Mansfield Power Station
On January 10 and 11, 1995, NIOSH investigators collected bulk, hand wipe, and PBZ samples from 27 plumbers and steam fitters for metals, respirable dust, and silica during the scheduled rebuilding of coal-fired boiler unit #2 at the Bruce Mansfield Power Station in Shippingport, Pennsylvania (NIOSH, 1996).  Forty-five full-shift PBZ samples for metals were collected on plumbers and steamfitters who removed boiler drains and retractable soot blowers on the exterior of the boiler.  The samples were analyzed using NIOSH Method 7300 and the beryllium analytical limits of detection and quantitation were reported as 0.02 ug/sample and 0.12 ug/sample, respectively.  The PBZ total beryllium sample results ranged from nondetectable to 0.39 ug/m[3].  Thirty-two (74 percent) of the samples were nondetectable for beryllium (less than 0.02 ug/m[3]); eight samples (19 percent) had a trace amount of beryllium present; and three samples were positive with results of 0.11 ug/m[3], 0.14 ug/m[3] and 0.39 ug/m[3].  Approximately 42 percent (18 of 43) of the full-shift PBZ metal samples contained arsenic concentrations above the detection limit of  0.3 ug/m[3].  The arsenic concentrations ranged from trace levels to 31 ug/m[3], and three of the air samples measured arsenic exposures above the OSHA PEL.  NIOSH associated the higher results with poor housekeeping and work practices.
NIOSH -- Clinch River Power Plant
On September 25 - 28, 1995, NIOSH investigators collected bulk fly ash samples, hand wipe samples, and PBZ samples for metals, respirable dust, and silica during the scheduled rebuilding of a coal-fired boiler at the Clinch River Power Plant near Cleveland, Virginia (NIOSH, 1997).  A total of 12 bulk fly ash samples were collected inside and outside the boiler.  Bulk samples were analyzed for selected metals using NIOSH Method 7300 and the analytical limits of detection and quantitation for beryllium were reported as 0.08 ug/g and 0.26 ug/g, respectively.  Five bulk samples collected inside the boiler had beryllium levels that ranged from 0.4 ug/g to 10 ug/g.  Three of these samples were boiler scale/slag that was obtained by scraping material from boiler elements; the other two interior samples were obtained near refractory brick removal areas.  Seven bulk samples of settled dust collected outside the boiler had beryllium levels that ranged from 3 ug/g to 6 ug/g.  These samples were collected from various locations including on or near access portholes, on a nearby I-beam, on the exterior wall of the boiler, and on a soot blower.
A total of 42 PBZ samples for metals were collected on boilermakers and laborers. Samples were analyzed for 28 elements using NIOSH Method 7300.  The beryllium analytical limits of detection and quantitation were reported as 0.02 ug/sample and 0.06 ug/sample, respectively.  All PBZ samples were six hours or greater in duration except two; the shorter duration samples were collected on boilermakers moving elements on the outside of the boiler and had sampling durations of 121 minutes and 280 minutes.  Seven of the PBZ samples were collected on boilermakers working inside the boiler; 31 samples were collected on boilermakers working outside the boiler; and four PBZ samples were collected on laborers maintaining walkways and work areas by dry sweeping and vacuuming.
The results for boilermakers working inside the boiler ranged from nondetectable to a trace amount (five nondetectable sample results and two trace concentration results).  For boilermakers working outside the boiler, total beryllium results ranged from nondetectable to 0.37 ug/m[3].  The worker associated with the highest sample result of 0.37 g/m[3] was also exposed to arsenic above the OSHA PEL.  All other samples were reported as trace or non-detectable.  Beryllium sample results for the laborers ranged from nondetectable to a trace amount (two nondetectable sample results and two trace concentration results).  Samples with a trace of beryllium had a quantity between 0.02 to 0.06 ug/sample.
OSHA IMIS Data
OSHA also reviewed exposure data from OSHA's Integrated Management Information System (IMIS) for beryllium (OSHA, 2009).  The IMIS data includes information on industry and job descriptions, but does not include information on worker activities, workplace conditions, engineering controls, use of personal protective equipment, nondetectable concentrations, and sampling durations.  In addition, it is not possible to determine whether beryllium was included in the sample analysis request because there is known potential workplace exposure to beryllium, or because it was part of a routine metal screening.  For this application group, there are two corresponding SIC classifications: 4911 (Electric Services) and 4931 (Electric and Other Services Combined) with beryllium exposures in the IMIS database.
For the time period June 1978 to September 2003, the IMIS database includes 10 PBZ sample entries for beryllium in SIC classification 4911.  SIC classification 4911 includes hydroelectric, fossil fuel, nuclear electric, and other electric power generation; electric power transmission and control; and electric power distribution.  Thus, the PBZ entries in the IMIS database for SIC code 4911 might represent establishments other than coal-fired electric power generation plants.  Four of the sample entries are reported as nondetectable and six sample entries have positive beryllium results ranging from 0.01 ug/m[3] to 8.6 ug/m[3].  The nondetectable results are reported for workers with job descriptions of mechanic welder (two samples, March 1994), operator (one sample, August 1986), and technician (one sample, April 2006).  Three positive sample results of 0.01 ug/m[3] (February 1996) are reported for workers with a job description of fuel handler.  Two sample results of 0.05 ug/m[3] (March 2002) are reported for workers with a job description of pipe fitter; the highest sample result (8.6 ug/m[3], May 1987) is reported for a worker with a job description of electrician.
For SIC code 4911, the IMIS database also includes one area sample (March 1994), one screening sample with no job description (April 1991), one wipe sample (March 1994) for a job description of mechanic, and one bulk sample (March 1989) for a job description of fly ash loader.  OSHA assumes all of these samples were nondetectable because the result for each is listed as zero.
Table IV.B-2 summarizes the available PBZ beryllium exposure data discussed above. Results reported as less than the LOD or LOQ are incorporated into the exposure profile as volume-adjusted LOD or LOQ concentrations.
Table IV.B-2 -- Exposure to Beryllium in the Coal-Fired Electric Power Generation Industry (NAICS 221112)
                                 Job Category
                                No. of Samples
                               Range
(ug/m[3])
                                Mean
(μg/m[3])
                               Median
(μg/m[3])
Operations
                                       4
                                    <1.0
                                    <1.0
                                    <1.0
Maintenance
                                      96
                                 0.01 to 0.39
                                     0.05
                                     0.02
Routine Maintenance
                                      10
                                   0.17-0.17
                                     0.17
                                     0.17
Scheduled Outage Maintenance
                                      83
                                 0.02 to 0.39
                                     0.04
                                     0.02
Coal Handling
                                       3
                                     0.01
                                     0.01
                                     0.01
TOTAL
                                      100
                                 0.01 to 0.39
                                     0.06
                                     0.02
Source:  NIOSH, 1988, 1996, 1997; OSHA, 2004, 2009