Characterization of Lead Leachability from Cathode Ray Tubes Using the Toxicity Characteristic Leaching Procedure.

Stephen E. Musson, Yong-Chul Jang, Townsend T. and Il-Hyun Chung. (2000).

Environmental Science & Technology.34(20):4376-4381.
doi:10.1021/es0009020

Abstract : Cathode ray tubes (CRTs) in television and computer monitors are one of the most common components of discarded electronics in the solid waste stream. CRTs present a disposal problem because of their growing magnitude in municipal solid waste (MSW) and their role as a major source of lead in MSW. Using the EPA Toxicity Characteristic Leaching Procedure (TCLP), lead leachability from CRTs was studied. Lead leached from the CRT samples at an average concentration of 18.5 mg/L. This exceeded the regulatory limit of 5.0 mg/L. Several factors affected the lead concentrations of each CRT sample. These included the sample fraction of the CRTs, the particle size used in the tests, and the CRT type. The most significant quantities of lead were obtained from the funnel portion of the CRTs at an average lead concentration of 75.3 mg/L. The major source of lead in the funnel is the frit seal of color CRTs. Samples containing the frit seal had lead leaching levels nearly 50 times those without. Samples comprised of smaller particle sizes exposed a greater surface area resulting in higher lead leaching levels. While 21 of 30 color CRTs exceeded regulatory lead limits, none of the six monochrome CRTs did. Age of the CRTs was not a significant factor for lead leaching. These results provide useful information to the regulatory and waste management community for developing policies for managing discarded CRTs. 

Keywords : Cathode Ray Tube, TCLP, MSW, EPA.