Cathode ray tubes (CRTs) widely used in televisions and computer monitors are estimated by the Department to be the largest source of lead in Florida’s MSW (Figure 1).

Prior to 1998, lead acid batteries were the largest source of lead (Figure 2 ).

Figure 3 shows the parts of a disassembled computer monitor. The CRT is the tube that produces the image you see when you look at the monitor. The CRT glass has a negative net value but can be reused as glass cullet to make new CRTs or as a replacement for a silica based fluxing agent used in the lead acid battery recycling process. The circuit board, cone and copper cables have some positive scrap value. The cone is an electromagnet that encircles the electron gun at the rear (narrrow) end of the CRT. The cone directs the electron streams produced by the electron gun to the face plate of the CRT to produce the image that we see. The copper components of the cone’s windings give the cone much of its scrap value. The circuit board processes the incoming signal from the computer to control the operation of the electron gun so that the correct image appears on the monitor screen. The circuit board contains copper and very small amounts of gold and other precious and semiprecious metals that give the circuit board much of its scrap value. The rest of the monitor is plastic that can sometimes be recycled but usually has a negative or zero net value.

Figure 3
What’s in a computer monitor?  
Photo courtesy of Creative Recycling Systems, Brandon, FL

Figure 4 shows where the lead is in the various parts of a typical color CRT used in a TV or computer monitor. The lead in the funnel and face plate glass is bound up in the glass matrix and does not leach very readily. The lead in the frit which joins or welds the face plate glass to the funnel glass is in the form of a lead oxide paste. The lead in the frit does leach quite readily when subjected to the Toxicity Characteristic Leaching Procedure (TCLP) test used to determine whether a discarded material is a hazardous waste or not. Research done at the University of Florida and sponsored by the DEP shows that CRTs usually test to be a hazardous waste when subjected to the TCLP test.

Figure 4
Where’s the lead in a cathode ray tube (CRT)?  
Courtesy of Robin Ingenthron
Massachusetts Department of Environmental Protection

In 1998, the DEP began to focus on the proper management of discarded CRTs from televisions and computer monitors as well as other electronic equipment normally discarded along with CRTs, e.g., computers and computer peripheral equipment like printers and keyboards. One recent study, the National Safety Council’s EPR2 Baseline Report, May 1999, suggests that much of this obsolete equipment is being stored pending the clarification of its regulatory status and the development of recycling or other cost effective waste management options. Available studies and data show that very little recycling of CRTs and computers is going on at the present time. Figures 5 and 6 show estimates of quantities of obsolete and recycled TVs and computer monitors in Florida through 2003.

Figure 5:
Estimates of number of obsolete versus recycled televisions in Florida, 1999-2003. (Data from National Safety Council’s EPR2 Electronics Baseline Report, May, 1999)

Figure 6:
Estimates of number of obsolete versus recycled computer monitors in Florida, 1999-2003. (Data from National Safety Council’s EPR2 Electronics Baseline Report, May, 1999)