• Parts or components begin to fail more frequently because the machine is too old and uneconomical to keep. 
• The computer becomes obsolete for the application that it was originally intended. 
• Newer machines, often with improved features, arise to replace earlier models.

Eventually, the question arises: What to do with the old computers or parts? Can they simply be placed in the garbage bin so that they are hauled to the landfill and buried?

Computers and peripherals contain some environmentally unfriendly materials. Most computer components are either hazardous or contain some level of hazardous substances. Waste materials are listed as hazardous because they are known to be harmful to human health and the environment when not managed properly. Also known as toxic waste, hazardous materials typically contain high concentrations of heavy metals, such as cadmium, lead, or mercury. Computer printed circuit boards consist of plastics, precious metals, fiberglass, arsenic, silicon, gallium, and lead. CRTs (monitors) contain glass, metal, plastics, lead, barium, and rare earth metals. Batteries from portable systems can contain lead, cadmium, lithium, alkaline manganese, and mercury.

In addition to the computer parts that contain hazardous materials, many of the cleaning substances used on computer equipment can be classified as hazardous materials. Although these materials can be classified as hazardous materials, there are so far no widespread regulations when it comes to placing them in the landfill in the United States, for example. A similar situation prevails in most other parts of the world. The rest of this section is focused on those items that require special disposal procedures that comply with environmental guidelines. This will include such examples as batteries, cathode ray tubes (CRTs) or monitors, chemical solvents or cans and toner kits or cartridges (printers). Finally, the Material Safety Data Sheet (MSDS) is discussed.

Proper Disposal of Batteries
Batteries often contain rare earth metals that can be harmful to the environment. Typically, batteries from portable computer systems can contain lead, cadmium, lithium, alkaline manganese, and mercury. These metals do not decay and will persist in the environment for many years if not carefully disposed of. Mercury, being one of the elements commonly used in the manufacturing of batteries, is extremely toxic (harmful) to humans. Lead and the other metals, although not as harmful as mercury, can still cause problems to the environment.

Because of these metals, depleted batteries are classified as hazardous materials. The disposal of batteries is, therefore, tightly controlled both at the national and state or local levels. In addition to the federal guidelines on disposal of batteries and other potentially harmful materials into the environment, most states and local communities in the United States have enacted laws designed to control where and how batteries can be disposed.

The desired method for the proper disposal of batteries is recycling, if possible. Additionally, note that all batteries, including lithium-ion, nickel-cadmium, nickel-metal hydride, and lead-acid are subject to the special disposal procedures that satisfy required compliance with existing environmental guidelines. However, because the regulations may vary from state to state and from country to country, it is recommended to contact the people who handle trash removal for the company or local community for more information. They can either arrange for special disposal facilities or provide a supplier that can remove batteries safely.

Proper Disposal of CRTs

• Safety Concerns with CRTs – The preventive maintenance work related to the computer monitor is basic and mostly limited to using lint-free linen to clean the screen and dusting the air ducts in the back. However, the safety concerns that are directly related to the computer monitor, otherwise called the cathode ray tube (CRT), cannot be over emphasized. One way to appreciate the potential hazard associated with monitors is to understand how they work. Monitors work by directing electrons at the screen under the guide of a powerful magnet. Note that the electrons are in essence pure electric energy. When electrons hit the front of the screen, they are really striking a coating that is applied to the inside of the monitor. The coating is known as phosphor. The phosphor is an element that glows for a short period of time when it is struck by flying electrons. A tight grouping of added primary colors including red, green, and blue provides the different colors that a user can display on a monitor, simply put. By striking the appropriate phosphors with a controlled amount of electrons, any color can be achieved.

  All of these electrons flying around and the huge magnets needed to deflect them cause a computer monitor to build up high voltages, sometimes up to 25000 volts. Unfortunately, a CRT monitor can continue to maintain a high voltage for a long time, even after power is removed. Therefore, as with power supplies mentioned previously, never ever open a monitor, even to retrieve something dropped in it. The risks of electrocution always remain high.

• Safe disposal of CRTs – CRTs that have come to an end-of-life must always be handled with care due to the potentially lethal voltage that is maintained even after being disconnected from power. Additionally, CRTs contain glass, metal, plastics, lead, barium, and rare earth metals. According to the U.S. Environmental Protection Agency (EPA) CRT monitors contain four pounds of lead on average (the exact amount depends on size and make). Lead and many of the other metals, as mentioned in the previous section, have been cited as toxic. Therefore, they are harmful to the environment and humans. Like the case of batteries, all or most of the components of end-of-life CRT monitors can be salvaged or recycled. Monitors must be disposed of in compliance with environmental regulations. Consult the local waste collection agent or recycling company for information on how best to deal with end-of-life CRTs.

Proper Disposal of Toner Kits, Cartridges, and Developers
Used toner kits, cartridges, and developers (from printers) can be destructive to the environment. Their sheer volume necessitates caution in the way they are handled and disposed.

Laser printer toner cartridges can be refilled and recycled. Ink cartridges from ink-jet printers can also be refilled and reused. Most of the time, when a new toner cartridge is purchased, the old cartridge can be exchanged for a small credit from the supplier. At the very least, the vendor will accept the old cartridges for processing. This is the preferred method for disposing of cartridges. The cartridges are eventually returned to the manufacturer to be recycled and reloaded with toner and developer so that they can be resold.

Proper Disposal of Chemical Solvents and Aerosol Cans
The chemicals and solvents that are used to clean computers are another source of environmental problems. When leached (drained or evaporated) into the environment, these chemicals can cause significant damage. Therefore, when it comes to the chemical solvents used to clean computers, as well as the containers they come in, it will normally be necessary to clear these items with the local waste management agencies before disposing of them. As with batteries, contact the sanitation provider to find out how and where to dispose of these chemicals. Never dump them down the sink or dispose of them in any drain that connects to the public sewers (the underground pipeline that collects municipal liquid waste from households or industry).

Free liquids are those substances that can pass through a standard paint filter. Many dump sites will not handle free liquids, and they cannot be disposed of in the landfill. Therefore, solvents and other liquid cleaning materials must be properly categorized and disposed of at an appropriate type of disposal center.

Additionally, any cans or bottles that the solvents and other cleaning supplies came in must also be specially treated. Make sure that they are identified and treated as special hazardous waste. Some aerosol cans whose contents are not completely used up can explode when exposed to heat.

Using Material Safety and Data Sheets (MSDS)
To determine if a material used in PC repairs or preventive maintenance is classified as hazardous, consult the Material Safety Data Sheet (MSDS). In addition to the solvents and chemicals already identified, the Occupational Safety and Health Administration (OSHA) has developed a series of data sheets on hazardous materials indicating hazards and their handling. All hazardous materials are required to have Material Safety Data Sheets (MSDS) that accompany them when they change hands. This means that some of the products purchased for computer repairs or maintenance come with relevant MSDS information in the manual.

OSHA requires that organizations working directly with these materials post the data sheets in prominent areas. MSDS are a valuable source of information and typically contain the following information:

• The name of the material
• Its physical properties
• Any hazardous ingredients it contains
• Reactivity data, including fire and explosion data
• Spill or leak procedures
• Any special precaution information
• Health hazard information
• Any special protection information

MSDS is used to inform workers and management about hazards associated with the products and how to handle them safely. It is extremely valuable in helping to determine how best to dispose of any potentially hazardous materials. Generally, local regulations concerning acceptable disposal methods for computer-related components should always be checked before disposing of any electronic equipment.
 

Worksheet  (PDF, 7 KB)   Environmental Considerations