The first thing to understand is that any TV or computer monitor that is based on a cathode ray tube (CRT) contains a lot of glass (see How TVs Work for a description of CRTs). If you have ever tried picking up a 21-inch (53-cm) monitor or a 25-inch (or larger) TV, you know that all the glass in a large CRT can easily weigh more than 50 pounds (23 kg).
It turns out that the glass in a CRT contains a lot of lead. A big CRT can contain up to 5 pounds (2.2 kilograms) of lead. It is mixed into the glass for two reasons:
- It improves the optical quality of the glass. Adding a small amount of lead to glass is very common when creating glass for lenses, and you may have also heard of leaded crystal. Optical quality is especially important at the front of the CRT.
- It acts as a shield against radiation generated by the electron gun and electron beam.
The problem with lead is that very small amounts of it cause lead poisoning, so there is a large effort to keep lead out oflandfills and incinerators. Communities in the United States have programs to recycle CRTs and television sets.
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FAQs
Harmful radiation is generated when an image is created on a CRT screen. In order to shield viewers from this radiation, a substantial amount of lead is incorporated into the glass used to manufacture the various glass components of a CRT (approximately 4 pounds of lead per CRT).
Where is the lead in a CRT TV? ›
Due to the presence of lead located in the funnel glass, CRTs marked for disposal are considered hazardous waste under the Resource Conservation and Recovery Act (RCRA).
What do CRT monitors contain? ›
A cathode-ray tube (CRT) is a vacuum tube containing one or more electron guns, which emit electron beams that are manipulated to display images on a phosphorescent screen.
Is there lead in computer monitors? ›
Electronic waste or E-waste such as televisions, computers and monitors contain toxic components. A typical computer processor and monitor contain five to eight pounds of lead and heavy metals such as cadmium, mercury and arsenic.
Why are CRT monitors so good? ›
Still, CRTs have their perks. Most have a better contrast ratio and higher refresh rates than modern LCD monitors, so content looks richer and deeper. There's a sub-culture of first-person shooter fans who swear FPS games always look best on a high-end CRT monitor. A CRT is also a window into an entire era of media.
Why is lead used in CRT? ›
Harmful radiation is generated when an image is created on a CRT screen. In order to shield viewers from this radiation, a substantial amount of lead is incorporated into the glass used to manufacture the various glass components of a CRT (approximately 4 pounds of lead per CRT).
Do CRT TVs have lead? ›
Recycled CRTs are disassembled so recoverable components can be routed into streams of commodities that can be reused or converted into raw materials again. CRT monitors and televisions contain lead, which is located in the funnel glass. Lead is just one of the hazardous waste components in CRT displays.
Are CRT monitors safe? ›
CRT tubes emit radiation.
CRTs emit x-rays due to the electron beams bombarding the shadow mask or aperture grille and phosphors. Because of this, CRT monitors are bad for your eyes if you are exposed over a long period of time. The best way to avoid these dangers is to replace your CRT with a LCD screen.
Are old CRTs safe? ›
Unless you are messing with the picture tube, and the TV is turned off and unplugged, there is not much danger. If it is plugged in and/or turned on, keep your hands out. There are deadly voltages located in several accessible areas within. In addition, the inside of the CRT tube is a high vacuum.
Are CRTs hazardous? ›
CRTs contain lead in the funnel glass, so they are considered hazardous waste as per the Resource Conservation and Recovery Act (RCRA). There are other hazardous substances within CRTs, but lead is the biggest Hazardous constituent.
We offer a wide range of different cables to connect up your monitors. We have HDMI, Mini HDMI, DisplayPort, Mini DisplayPort and DVI to name a few.
How much lead is in a computer? ›
Lead: Lead makes up about 6% of the total weight of a computer and is used in the CRT of monitors and to solder (a method of connecting) components on printed circuit boards.
Do all electronics contain lead? ›
Almost all electronic devices contain lead, with old cathode ray tube (CRT) monitors and televisions weighing in at an average 4-5 lbs of lead each, and with smaller devices containing traces of lead from soldering.
Who still uses CRT? ›
CRT technology is common in the vacuum tube industry as a whole, which continues to serve many applications across a wide variety of industries. These include: Lighting: incandescent, fluorescent, & high-power arc lamps. Communications: microwave, traveling wave, & high-power amplifier tubes.
Is CRT still better? ›
The CRT monitors are superior to plasma and LED monitors but not to OLED. The latter are as fast, have much better static contrast, color reproduction. No flicker at high brightness. Bigger screen size.
How long will a CRT monitor last? ›
In this study, the median lifespans for the CRT and flat-screen monitors were found to be 8 and 12 years, respectively (Fig.
How many leads are in a CRT device? ›
Unlike other pacemakers that have one or two wires or leads, a CRT, or biventricular pacemaker, has three. One lead goes to each of your ventricles. The third goes to your right atrium, one of your heart's upper chambers. (Your heart has two ventricles and two atria.)
How much lead is in old TVs? ›
The glass cathode ray tubes and circuit boards in older TVs contain an average of 4 to 8 pounds of lead – a potent neurotoxin that can cause brain damage in children. TV screens and tubes also contain other toxic substances such as barium and cadmium.
Do all TVs contain lead? ›
Because even though flat screen TVs don't contain all of the toxic substances found in older TVs, including lead, mercury, arsenic, cadmium, chromium, and barium, they still contain some of them.
What is the lead content of CRT glass? ›
CRT glass types
The front panel has very low lead content, though it contains a phosphor coating that must be cleaned off before the glass can be safely reused in most situations. The funnel and neck portions of a CRT have a higher lead content by weight, ranging from 15 to 34%.
