Control technology and exposure assessment for electronic recycling operations, Elkton Federal Correctional Institution, Elkton, Ohio, report no. EPHB-326-12a.
Researchers from the National Institute for Occupational Safety and Health (NIOSH) conducted a study of the recycling of electronic components at the Federal Prison Industries facilities (aka, Unicor) in Elkton, Ohio, to assess workers' exposures to metals and other occupational hazards, including noise, associated with these operations. An in-depth evaluation was conducted from February 26 to March 2, 2007, and a follow-up survey was conducted from December 11 to 13, 2007, to evaluate changes made in selected activities as a result of initial recommendations. The electronics recycling operations at Elkton can be organized into four production processes: a) receiving and sorting, b) disassembly, c) glass breaking operations, and d) packaging and shipping. A fifth operation, cleaning and maintenance, was also addressed but is not considered a production process per se. It is known that lead (Pb), cadmium (Cd), and other metals are used in the manufacturing of electronic components and pose a risk to workers involved in recycling of electronic components if the processes are not adequately controlled or the workers are not properly trained and provided appropriate personal protective clothing and equipment. Methods used to assess worker exposures to metals during this evaluation included: personal breathing zone and area sampling for airborne metals; particle size sampling; surface wipe sampling to assess surface contamination; and bulk material samples to determine the composition of settled dust. Samples were analyzed for up to 31 metals with five selected elements (barium, beryllium, cadmium, lead and nickel) given emphasis. Noise exposures were determined using personal dosimeters. The results of air sampling conducted during the February / March visit indicated that the highest exposures occurred to workers during the filter change-out maintenance operation. Airborne concentrations of Cd and Pb measured during filter change-out showed an 8-hour time weighted average of about 150 times the OSHA Permissible Exposure Limit (PEL) for Cd and 15 times the OSHA PEL for Pb for one of the two workers. Air samples collected on a second worker showed airborne concentrations of 30 times the PEL for Cd and 4 times the PEL for Pb. In both cases the results showed that the Cd concentrations exceeded the assigned protection factor for the powered air-purifying respirator being used by the workers. An overexposure to Cd was also found during the weekly clean-up operation. Although beryllium is used in consumer electronics and computer components, such as disk drive arms (beryllium-aluminum), electrical contacts, switches, and connector plugs (copper-beryllium) and printed wiring boards [Willis and Florig 2002, Schmidt 2002], most beryllium "in consumer products is used in ways that are not likely to create beryllium exposures during use and maintenance" [Willis and Florig 2002]. This may account for the fact that beryllium in this study was measured in only two samples at levels above the detection limit of the analytical method. The removal and sorting of components seen here is typical of a maintenance activity (components are removed from the cases and sorted, rather than removed and replaced). Other e-recycling activities that include further processing, such as shredding of the components, may produce higher exposures to beryllium but these processes are not done at this facility. Samples collected during routine daily glass breaking operations were less than 20% of the OSHA PELs for both Cd and Pb. Samples collected on disassembly workers in the general factory area of all three buildings ranged from non-detectable to 10% of the OSHA PEL for Cd and ranged from non-detectable to 5% of the OSHA PEL for Pb. Unless specified, results of samples presented are for duration of sample and not calculated on an 8 hour time weighted average basis. Lead, cadmium and other heavy metals were detected in the surface wipe and bulk dust samples. There are few established standards available for wipe samples with which to compare these data. Most of the surfaces tested for lead indicated levels exceeding the most stringent criteria. The wipe sample results can not be used to determine when the contamination occurred. They only represent the surface contamination present at the time the sample was collected. Measurement of noise levels indicated several samples exceeding the REL and TLV of 85 dBA. One sample exceeded the PEL of 90 dBA and 3 other samples exceeded 50% of the allowable dose requiring that those employees be placed in a hearing conservation program. As a result of the February/March 2007 survey, it was recommended that the filter change operation be modified and that improved dust suppression methods be used to reduce airborne concentrations. Specific recommendations (implemented prior to the second evaluation) include: 1) the use of water spray to suppress dust during the filter change-out operation; 2) the immediate bagging and disposal of used filters rather than attempting to clean and re-use them; and 3) the use of HEPA vacuums and wet mopping to remove dust from the floor and work surfaces. Measurements made during the follow-up survey in December 2007 indicated significant reductions in the levels of airborne contaminants during this modified operation although respiratory protection during the filter change operation continues to be necessary and other improvements are needed. These improvements are described in detail later in this report. Recommendations resulting from this study include: 1. The respiratory protection program for this facility should be evaluated for this operation in order to ensure that it complies with OSHA regulations. 2. Attention should be focused on practices to prevent accidental ingestion of lead. 3. Management should evaluate the feasibility of providing and laundering work clothing for all workers in the recycling facility. 4. Change rooms should be equipped with separate storage facilities for work clothing and for street clothes to prevent cross-contamination. 5. A hearing conservation program must be implemented for workers in the glass breaking operation. 6. All Unicor operations should be evaluated from the perspective of health, safety and the environment in the near future. 7. A comprehensive program is needed within the Bureau to assure both staff and inmates a safe and healthy workplace.
Control-technology; Engineering-controls; Prison-workers; Correctional-facilities; Heavy-metals; Analytical-methods; Sampling; Barium-compounds; Beryllium-compounds; Cadmium-compounds; Lead-compounds; Nickel-compounds; Dust-exposure; Dusts; Heat-stress; Region-5; Environmental-contamination; Exposure-assessment; Exposure-levels; Exposure-limits; Occupational-health-programs; Occupational-safety-programs; Clothing; Electronic-components; Electronic-devices
National Institute for Occupational Safety and Health, Division of Applied Research and Technology, Mail Stop R-5, 4676 Columbia Parkway,Cincinnati, OH 45226