Leaching Assessments of Hazardous Materials in Cellular Telephones JOHN D. LINCOLN, † OLADELE A. OGUNSEITAN,* ,‡ ANDREW A. SHAPIRO, § AND JEAN-DANIEL M. SAPHORES | Department of Chemical Engineering and Materials Science, Public Health Program, College of Health Sciences, and Program in Industrial Ecology, Department of Environmental Health, Science, and Policy, Department of Electrical Engineering and Computer Science, Department of Civil and Environmental Engineering, Economics Department, and Department of Planning, Policy, and Design, University of California, Irvine, California 92697 Protocols for assessing the risks of discarded electronic products (e-waste) vary across jurisdictions, complicating the tasks of manufacturers and regulators. We compared the Federal Toxicity Characteristic Leaching Procedure (TCLP), California’s Waste Extraction Test (WET), and the Total Threshold Limit Concentration (TTLC) on 34 phones to evaluate the consistency of hazardous waste classification. Our sample exceeded TCLP criteria only for lead (average ) 87.4 mg L -1 ; range ) 38.2-147.0 mg L -1 ; regulatory limit ) 5.0 mg L -1 ), but failed TTLC for five metals: copper (average 203 g kg -1 ; range ) 186-224 g kg -1 ; limit ) 2.50 g kg -1 ), nickel (9.25 g kg -1 ; range ) 6.34-11.20 g kg -1 ; limit ) 2.00 g kg -1 ), lead (10.14 g kg -1 ; range ) 8.22- 11.60 g kg -1 ; limit ) 1.00 g kg -1 ), antimony (1.02 g kg -1 ; range ) 0.86-1.29 g kg -1 ; limit ) 0.50 g kg -1 ), and zinc (11.01 g kg -1 ; range ) 8.82-12.80 g kg -1 ; limit ) 5.00 g kg -1 ). Thresholds were not exceeded for WET. We detected several organic compounds, but at concentrations below standards. Brominated flame retardants were absent. These results improve existing environmental databases for e-waste and highlight the need to review regulatory testing for hazardous waste. Introduction Rapid improvements in consumer electronic devices (CEDs) and their ever wider distribution have sharply increased the quantity of electronic equipment entering the solid waste stream (1). Electronic waste (e-waste) contains a variety of hazardous materials, including toxic metals such as antimony, copper, nickel, lead, and others, and organic compounds such as phthalates and brominated flame retardants (BFRs), that could potentially leach into the environment after disposal and threaten human health (2-6). Unfortunately, CEDs are not recycled at the same rate (less than 10%) as other hazardous consumer products (24-90%), partly be- cause they represent a new and poorly understood category of waste (7). Furthermore, the small size of CEDs increases the likelihood of their disposal in landfills. The U.S. Envi- ronmental Protection Agency reported that 4600 million kg of electronic products was discarded in landfills in the U.S. in 2000. Furthermore, an estimated 130 million cellular phones were retired in the United States in 2005, with a cumulative estimate of more than 700 million phones already discarded or stockpiled prior to disposal (8). As a result of this growing volume of e-waste, it is estimated that ap- proximately 454 million kg of Pb will enter the environment in the next 10 years, although this estimate was derived when cathode ray tubes (CRTs) were likely the largest contributors, but they are slowly being phased out in favor of flat screen panels, which provoke somewhat different concerns regard- ing toxic material constituents (8). To assess the need to regulate the disposal of e-waste items based on their hazardous material content, a variety of testing procedures have been proposed and implemented by different regulatory agencies at the state, national, and international levels. In the United States, these methods include the U.S. EPA Toxicity Characteristics Leaching Procedure (TCLP) (9) and Synthetic Precipitation Leaching Procedure (SPLP) (10), the California Department of Toxic Substance Control (DTSC) Waste Extraction Test (WET) (11), and the California DTSC’s Total Threshold Limit Concentra- tions (TTLC, or “Totals test”) (11). In some cases, these test procedures were designed, with important caveats, to simulate landfill conditions, but they exhibit significant methodological differences that suggest the likelihood of drastically different results. For example, the leaching solution is deionized water in Europe and Japan, whereas in the United States both deionized water and acidic solutions are used, depending on Federal or state-level requirements (12). In California, waste materials that fail the Federal TCLP, California WET (compared to the Soluble Threshold Limit Concentration, STLC), or California TTLC are considered hazardous. If a leachate solution contains toxic materials at concentrations that exceed regulatory limits, the material is determined to have failed the test. TCLP and WET are leaching test procedures that include mechanical preparation of the sample, solution extraction of hazardous materials, and chemical analysis of the extracted solution. The TTLC test requires acid digestion and analysis and is therefore not meant to simulate landfilling scenarios, but instead to provide data on the elemental constituents in products. This infor- mation may be useful for evaluating options for remanu- facturing strategies to reduce the use of toxic chemicals. Several studies have used various leaching procedures to characterize e-waste (13-16), and they demonstrate that Pb is the metal that most frequently exceeds regulatory thresh- olds for hazardous waste at all jurisdictional levels. Therefore, regulatory agencies have focused on replacing Pb in electronic products (2). It is becoming clear that, even after Pb is replaced in electronic products, e-waste may remain classified as “hazardous” because of the presence of other toxic materials that may leach out, depending on the test protocol. However, there has been no clear consensus on the identity or concentrations of the other toxic materials. In this study, we focused on TCLP (U.S. EPA), WET (State of California), and TTLC Totals Test (State of California) because these tests generally represent worst-case scenarios for leaching as procedures for Europe, Japan, and many states utilize less aggressive neutral leachate solution than the low-pH TCLP and WET procedures. Therefore, despite their assumptions, * Corresponding author phone: (949) 824-6350; fax: (949) 824- 2056; e-mail: Oladele.Ogunseitan@uci.edu. † Department of Chemical Engineering and Materials Science. ‡ Public Health Program, College of Health Sciences, and Program in Industrial Ecology, Department of Environmental Health, Science, and Policy. § Department of Electrical Engineering and Computer Science. | Department of Civil and Environmental Engineering, Economics Department, and Department of Planning, Policy, and Design. Environ. Sci. Technol. 2007, 41, 2572-2578 2572 9 ENVIRONMENTAL SCIENCE & TECHNOLOGY / VOL. 41, NO. 7, 2007 10.1021/es0610479 CCC: $37.00  2007 American Chemical Society Published on Web 02/21/2007