Environmental harms can come from many sources. Not only are temperature and humidity elements that must be controlled, but administrators need to also carefully monitor power, air, and particulates that can harm humans and computers. Not understanding environmental impact and controls can cause great harm.

The following sections look at what you should know of the topics beneath 5.2 as you study for the upcoming exam.

MSDS Documentation for Handling and Disposal
It is important that you know the potential safety hazards that exist when working with computer elements and how to address them. It is imperative that you understand such issues as material safety data sheets (MSDSes) and know how to reference them when needed. Any type of chemical, equipment, or supply that has the potential to harm the environment or people has to have an MSDS associated with it. These are traditionally created by the manufacturer, and you can obtain them from the manufacturer or from the Environmental Protection Agency at www.epa.gov.

These sheets are not intended for consumer use but are aimed at emergency workers and employees who are exposed to the risks of the particular product. Among the information they include are such things as boiling point, melting point, flash point, and potential health risks. They also cover storage and disposal recommendations, and the procedures to follow in the case of a spill or leak.

Temperature, Humidity Level Awareness and Proper Ventilation
Three items closely related to an environmentally friendly computing environment are temperature, humidity, and ventilation. We will look at the most important elements with all three.

Temperature
Heat and computers don't mix well. Many computer systems require both temperature and humidity control for reliable service. The larger servers, communications equipment, and drive arrays generate considerable amounts of heat; this is especially true of mainframe and older minicomputers. An environmental system for this type of equipment is a significant expense beyond the actual computer system costs. Fortunately, newer systems operate in a wider temperature range. Most new systems are designed to operate in an office environment.

If the computer systems you're responsible for require special environmental considerations, you'll need to establish cooling and humidity control. Ideally, systems are located in the middle of the building, and they're ducted separately from the rest of the heating, ventilation, and air conditioning (HVAC) system. It's a common practice for modern buildings to use a zone-based air conditioning environment, which allows the environmental plant to be turned off when the building isn't occupied. A computer room will typically require full-time environmental control.

Humidity Level
Another preventive measure you can take is to maintain the relative humidity at around 50 percent. Be careful not to increase the humidity too far -- to the point where moisture starts to condense on the equipment! It is a balancing act keeping humidity at the right level since low humidity causes ESD and high humidity causes moister condensation. Both extremes are bad, but have completely different effects.

Also, use antistatic spray, which is available commercially, to reduce static buildup on clothing and carpets. In a pinch, a solution of diluted fabric softener sprayed on these items will do the same thing.

At the very least, you can be mindful of the dangers of ESD and take steps to reduce its effects. Beyond that, you should educate yourself about those effects so you know when ESD is becoming a major problem. 

Ventilation
Rounding out temperature and humidity is ventilation. It is important that air -- clean air -- circulate around computer equipment to keep it cool and functioning properly. Server rooms require much more attention to ventilation than office spaces, but are the subject of other exams (Server+, for example) and not test fodder for A+.

What is test fodder is the topic of ventilation within the computer itself - an inadequate flow of internal air within a computer is a common cause of overheating. To prevent this, know that all slot covers should remain in place and be replaced if a card is removed from the system. Know as well that internal fans should be periodically cleaned to ensure proper air flow. A missing slot cover or malfunctioning fan can lead to that inadequate flow of internal air.

Power Surges, Brownouts, Blackouts
There are a number of power-related threats that can harm computers. Among them are the following:

• Blackout: A complete failure of the power supplied.
• Brownout: A drop in voltage lasting more than a few minutes.
• Sag: A very short-term voltage drop.
• Spike: The opposite of a sag, this is a short (typically under 1 second) increase in voltage that can do irreparable damage to equipment.
• Surge: A long spike (sometimes lasting many seconds). Though they are typically a less intense increase in power, they can also damage equipment.

The two solutions to know for the power issues on the exam are battery backups and surge suppressors.

Battery Backup
A battery backup, or uninterruptible power supply (UPS), turns keeps the system up and running when the normal power is removed (blackout, brownout, etc.). Even in installations which use generators to keep the systems running, battery backups are usually still used so they can keep the machines running while the generators come up to speed.

Most UPS units come with software that can be used to configure the actions to take when the battery backup is active. The software, for example, can be configured to shut the connected devices down when the battery begins to get low.

Surge Suppressor
A surge suppressor (also known as surge protectors) keeps a spike from passing through it and on to the equipment that could be damaged. Tripping occurs when the breaker on a device such as a power supply, surge protector, or UPS turns off the device because it received a spike. If the device is a UPS, when the tripping happens, the components plugged in to the UPS should go to battery instead of pulling power through the line. Under most circumstances, the breaker is reset and operations continue as normal.

Nuisance tripping is the phrase used if tripping occurs often and isn't a result of a serious condition. If this continues, you should isolate the cause and correct it, even if it means replacing the device that continues to trip.

Surge suppressors, either stand-alone or built into the UPS, can help reduce the number of nuisance trips. If your UPS doesn't have a surge protector, you should add one to the outlet before the UPS in order to keep the UPS from being damaged if it receives a strong surge.

All units are rated by Underwriters Laboratories (UL) for performance. One thing you should never do is plug a UPS or computer equipment into a ground fault circuit interrupter (GFCI) receptacle. These receptacles are intended for use in wet areas, and they trip very easily. Warning: Don't confuse a GFCI receptacle with an isolated ground receptacle. Isolated ground receptacles are identifiable by orange outlets and should be used for computer equipment to avoid their picking up a surge passed to the ground by any other device.

Protection from Airborne Particles
Computers don't do well with airborne particles. To protect them from such, you can use enclosures for your sensitive equipment and air filters to condition the air.

Enclosures
Enclosures can be considered the first line of defense against particulates. Enclosures are available that can filter the air, keep air out, etc. Make certain that the enclosure you turn to for a solution still offers the necessary ventilation needed to prevent overheating.

Air Filters
Most enclosures incorporate an air filter to clean the air before allowing it to enter. An analogy to think of is the air filter on a car which keeps dirt, dust, bugs, and other things from the intake. When working with air filters, make certain they are kept clean and changed per the manufacturer's requirements.

Dust and Debris
One of the most harmful atmospheric hazards to a computer is dust. Dust, dirt, hair, and other airborne contaminants can get pulled into computers and build up inside. Because computer fans work by pulling air through the computer (usually sucking it in through the case and then pushing it out the power supply), it's easy for these items to enter and then become stuck. Every item in the computer builds up heat, and these particles are no exception. As they build up, they hinder the fan's ability to perform its function, and the components get hotter than they would otherwise.

The heat that builds up can lead to chip creep and other conditions. Heating the pins too much causes expansion and keeps them seated tighter, but heating them too far and then cooling them repeatedly (at shutdown) causes the chips to gradually creep out of the sockets.

Compressed Air
You can remove dust and debris from inside computers with compressed air blown in short bursts. The short bursts are useful in preventing the dust from flying too far out and entering another machine, as well as in preventing the can from releasing the air in liquid form. Compressed air cans should be held 2–3 inches from the system and always used upright so the content is released as a gas. If the can becomes cold to the touch, discontinue using it until it heats back to room temperature. Note: It's possible to use an air compressor instead of compressed-air cans when you need a lot of air. If you take this approach, make sure you keep the pounds per square inch (PSI) at or below 40, and include measures on the air compressor to remove moisture.

Vacuums
Dust can build up not just within the computer but also in crevices on the outside. These ports need to be blown out with compressed air, or cleaned with an electronic vacuum, before being used, or else degradation with the device connected to them could occur.

Handling and Protecting Components
When handling components, take appropriate measures to make certain you do not inflict harm by so doing. Commonsense is usually a good rule of thumb.

Antistatic Bags
Antistatic bags protect sensitive electronic devices from stray static charges. The bags are designed so that static charges collect on the outside of the bags rather than on the electronic components. You can obtain these bags from several sources. The most direct way to acquire antistatic bags is to go to an electronics supply store and purchase them in bulk. Most supply stores have several sizes available. Perhaps the easiest way to obtain them, however, is to hold onto the ones that come your way. That is, when you purchase any new component, it usually comes in an antistatic bag. Once you have installed the component, keep the bag. It may take you a while to gather a sizable collection of bags if you take this approach, but eventually you will have a fairly large assortment. Note: Always put the component in an antistatic bag and not on the bag. The outside of the bag is a common location for ESD to collect.

Complying with Regulations
As careful as you try to be, there is always the possibility for accidents to occur. Accidents can be environment-related (for example, a flash flood no one could predict suddenly overtakes the server room and shorts out the wiring), or caused by humans (someone mixes the wrong cleaning chemicals together to try and make their own concoction). Regardless of the cause or circumstances, one thing is written in stone: you must fully and truthfully document the problem.

While that documentation must be seen by internal parties (managers, human resources, etc.), it may also need to be seen by external parties. The latter depends on the type of industry that you are in and the type of incident that occurred. For example, if a large amount of battery acid is spilled in the ground, you should contact the Environmental Protection Agency (see reporting procedures at www.epa.gov).