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A+ Study Guide: Domain 7.0: Safety and Environmental Issues

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Electrostatic Discharge
Protecting Data

There are 2 things you need to remember about computers. First, they are electical machines made up of many points of failure. Second, they contain a number of components that are not friendly to the environment. In this section, you will learn how to identify potential hazards, how to deal with them, and how to be an eco-friendly technician.

Accidents can be avoided by identifying hazards in advance. One of the best ways to do this is to always read MSDS information when available. Hazardous materials come with Material Safety Data Sheets (MSDS) that provide a variety of information for handling the material. This can include: physical data, toxicity, health effects, first aid, reactivity, storage, disposal, protective equipment, and spill/leak procedures. It is important to read this information before using hazardous products. It is also a good idea to keep these documents and make them easily accessible in case of an accident.

Electrostatic Discharge:
Electrostatic Discharge (ESD) can be harmful to electronic components and cause them to fail. Low humidity, walking across carpet, and appliance motors are some of the common generators of ESD. Metal oxide semiconductor devices are particularly sensitive to ESD and special care should be taken around them. Below are some of the prevention methods employed to prevent damage:
  • Use grounding straps when working on the inside of a computer. Grounding straps are connected to a technicians wrist and you can ground the wrist strap to the earth pin on a wall socket.
  • Remove all metallic jewelery.
  • Use anti-static mats.
  • Before working on the inside of a computer, touching the chassis of the computer while plugged into a grounded outlet can prevent ESD.
  • Anti-static sprays can be applied to floors, computers and work surfaces.
  • A humidifier can be used to keep the humidity above 50%.
An ESD wriststrap should never be worn when working with high voltage equipment such as monitors.

When transporting or storing them, computer components should be placed in an anti-static foam or an anti-static bag.

A computer needs a "clean" electricity source in order to work properly. By "clean" we mean a source that is not plagued with spikes or dips in current. Spikes are of particular concern because they can not only destroy your computer, they can kill you in some situations.

Electrical spikes (measured in nanoseconds) or surges (measured in milliseconds) can cause damage to system components or even data loss. Surge suppressors (often called "surge protectors") can prevent minor variances in power and provide a stable stream of electricity to the unit, however, they may not always work against larger surges. For this reason, computer equipment should be unplugged from the wall during electrical storms to prevent equipment damage and injury. Also keep in mind that not all power strips are surge suppressors even though they look the same.

Uninterruptable Power Supplies (UPS) provide power to the devices connected to it for a period of time in the event of power loss or sag for long enough to gracefully shutdown the computer and avoid data loss. Unnecessary peripherals such as scanners and printers should not be connected to a UPS as they can overload it.

Monitors and power supplies (including printers) should not be opened unless you are qualified to work on them. Deadly voltage (up to 30,000 volts) can be stored inside their capacitors for periods long after you turn them off. Leave monitor repair to the professionals or simply replace a bad monitor/power supply. It is not worth your life to try to fix one of these.

In the event that you suffer an electrical fire, you must only use a class C or class ABC fire extinguisher. You should keep one of these handy around computer equipment.

A number of computer components listed below contain toxic chemicals and should be recycled. If the computer isn't too old and is still working, donating it to an organization provides a good alternative. Here are a few of the most important items to recycle.

Laptop batteries are highly toxic and should always be recycled - do not let old batteries just sit around. If the battery is ruptured or broken do not handle it as the chemicals are dangerous. Computer monitors also contain highly toxic chemicals and they should be recycled as well.

Toner and ink jet cartridges don't contain any harmful chemicals, but they are not biodegradable and are piling up in landfills. Most printer manufacturers have some sort of cartridge recycling program and some of them will even save you money on your new cartridges. Check with your printer manufacturer for more information. NOTE: Make sure that when you open a laser printer you avoid the fuser until it has had time to cool down as it can result in severe burns.

If you need to recycle components, there are many companies that specialize in this type of disposal and recycling. Sometimes even your local garbage service is equipped to take these items off your hands. Call them and find out.

Protecting Data:
If you are not backing up your data and a hard drive fails, the data is not necessarily lost. Not if you have up to $25,000 to pay a recovery service that may or may not be able to get your data back. This is why it is so important to set up regularly scheduled backups for important data. In the old days this was difficult because Windows NT, for example, could only backup data to an expensive tape drive and scheduling was a complicated command line procedure. Newer operating systems such as Windows 2003, XP, and Vista can backup data to external drives, network drives, and other locations and scheduling is done through the GUI. Your backups should be stored in a fire-proof safe or at a separate location for protection against fire and theft.

Hard drives are vacuum sealed and their covers should never be opened except by professionals in a "clean room". You will likely ruin the drive and lose your data if you do this.

Because floppy disks are magnetic media, they should not be exposed to magnetic fields that can be produced by TVs, monitors, speakers, power supplies and appliances with motors.

All accidents involving injury or damage should be immediately reported to a supervisor or manager. Furthermore, the incedent should be well-documented. This is important, not only for establishing safety history and trends, but may be an important piece of documentation from a legal standpoint (i.e. workman's compensation).