Disposal of Waste Materials

Before you start

Objectives: learn which computer components represent the greatest concern in caring for the environment.

Prerequisites: no prerequisites.

Key terms: protection, batteries, CRT monitor, PC system, cartridges, solutions, solvents, environment


There are some general rules that we should consider. For example, the batteries that we find in most notebook PC systems are an issue. Those batteries are some kind of Ni-Cad, NIMH or LIH battery that provide power if a power outlet isn’t available. The problem is that a lot of times they don’t last more than two to maybe three years. The question is what do we do with the old batteries? In most countries it’s against the law to throw these batteries in the common trash because they’re loaded with toxic chemicals. We should dispose them in the manner dictated by local law. We should check and see if there is a recycling facility available in the near.

CRT Monitors

Another issue are old Cathode Ray Tube monitors. CRT monitor is loaded with bad substances. In addition to nasty substance they can also keep a charge. There’s a capacitor inside a CRT monitor that retains a very strong AC charge, up to 20,000 volts. We should not throw old monitors in the garbage. It’s also probably illegal so we should check and see if there is any place where we can take old monitors.

PC Systems

As we all know, computer that worth $2000 or $3000 few years ago, today might be worth $50 or even less. We’re probably going to find ourselves throwing away whole PC systems. Again, it’s probably illegal to throw the PC system in the common trash. In a PC system there’s actually a lot of precious metals inside. There are some companies that recycle these systems to extract the gold and the silver and other precious metals that are inside the PC. Most PC systems have about five to $20 worth of precious metals.

Printer Cartridges

Printer cartridges run out of toner all the time. Again, we shouldn’t throw them in the trash. Most manufacturers will accept the empty cartridges back from us, they will refill them and then resell them again. This reduces waste and it provides less expensive printer cartridges in the end. A recycled printer cartridge costs about the half of the price of a new one.

Solutions and Solvents

Sometimes we use cleaning solutions or solvents to clean our computer components and cases. Often it is against the law to pour this down the drain. Every cleaning solution that we work with should have a Material Safety Data Sheet (MSDS) associated with it. This sheet will tell us the dangers associated with using it, how it should be used, and it should tell us how it should be disposed of.


In most parts of the world there are laws that tell us what kind of materials can be put in the common trash and which types of materials have to be disposed of in some other manner. Waste materials include batteries, CRT monitors, whole PC systems, printer cartridges, solutions and solvents.