Operational Procedures · Topic 4 of 9
Safety and Environmental Controls
Use ESD protection, safe power handling, lifting, fire safety, safety data sheets, power protection and air quality controls when working on computers.
- 4 min
- Use an ESD strap, mat and antistatic bags, and ground equipment.
- Disconnect power before opening a computer.
- Do not open a PSU.
What it is
Technicians work around electricity, heavy equipment, chemicals and sensitive parts. Safety procedures protect people, and environmental controls protect the equipment and the surroundings. This page covers both, because they share the same habits: prepare the workspace, handle parts with care and dispose of waste correctly.
How it works
Electrostatic discharge (ESD)
ESD is a sudden flow of static electricity that can damage components even when you do not feel it. Prevent it with these items.
- ESD strap (wrist strap). Connects you to a ground so static drains away.
- ESD mat. Gives a grounded surface for parts.
- Antistatic bags. Store and carry parts when they are not installed.
- Equipment grounding. Plug equipment into a grounded outlet and connect to the chassis.
Low humidity makes static more likely, and very high humidity can cause condensation and corrosion.
Safe power handling
Disconnect power before opening a computer, and for a laptop remove the battery where possible. Do not open a power supply unit (PSU) or a monitor, because stored charge can remain after unplugging. Use a power supply with the right rating and never remove its earth pin.
Personal safety
| Hazard | Precaution |
|---|---|
| Lifting heavy equipment | Bend the knees, keep the back straight, lift with the legs, or ask for help |
| Sharp edges and dust | Wear gloves, safety goggles and an air filter mask where needed |
| Cables across the floor | Tidy or cover them to prevent tripping |
| Hot parts | Let them cool before handling |
| Electrical fire | Cut the power if safe, then use an extinguisher rated for electrical fires, never water |
Remove loose jewellery and tie back long hair when working inside equipment. Know where the nearest fire extinguisher and exit are.
The United States class letters on an extinguisher say which fires it suits.
| Class | Fire type |
|---|---|
| A | Ordinary combustibles such as paper, wood and cloth |
| B | Flammable liquids such as petrol and oil |
| C | Energized electrical equipment |
| D | Combustible metals |
| K | Cooking oils and fats |
Many extinguishers are multi class, for example an ABC dry chemical unit, and carbon dioxide units are common near electronics.
Toxic and hazardous waste
Batteries, toner cartridges, old displays and some components contain materials that should not go in ordinary trash. Take them to a recycling or hazardous waste service. Follow the regulations in your area.
A Safety Data Sheet (SDS), formerly called a Material Safety Data Sheet (MSDS), is a document from the manufacturer that explains the hazards of a substance, how to handle and store it, first aid and how to dispose of it.
Power protection
| Device or event | Meaning |
|---|---|
| Surge or spike | Short burst of high voltage |
| Sag or brownout | Drop in voltage |
| Blackout | Total loss of power |
| Surge protector (suppressor) | Absorbs spikes before they reach equipment, but does not keep power on |
| UPS (uninterruptible power supply) | Battery that keeps equipment running for a while and allows a safe shutdown |
A UPS also helps smooth out sags. For key computers and servers, a UPS is better than a surge protector alone.
Temperature, humidity and ventilation
Heat damages electronics and shortens their life. Keep equipment in a ventilated room with free airflow and do not block vents.
Keep humidity in a moderate range, as described above for ESD. Server rooms and wiring closets often need dedicated cooling.
Dust, debris and air quality
Dust blocks fans and traps heat. Clean it with compressed air held at a distance with the fan stopped, or a vacuum designed for electronics, and wear a mask in dusty areas. Enclosures and air filters protect equipment in dirty places such as workshops.
Compliance
Follow local rules for waste, workplace safety and electrical work. When unsure, check the company policy and the relevant regulation.
Never open a PSU or a cathode ray tube (CRT) monitor. Capacitors can hold a dangerous charge even when the device is unplugged.
What to remember for the exam
- Use an ESD strap, mat and antistatic bags, and ground equipment.
- Disconnect power before opening a computer.
- Do not open a PSU.
- Lift with the legs and ask for help with heavy items.
- Class C extinguishers are for electrical fires (A is ordinary combustibles, B is flammable liquids, D is metals, K is cooking oils), and water is not used on electrical fires.
- Recycle batteries, toner and old displays as hazardous waste.
- An SDS explains hazards, handling and disposal of a substance.
- A surge protector handles spikes. A UPS handles outages and sags.
- Keep equipment cool, ventilated and free of dust.
Common mistakes
Using a vacuum cleaner without care. Normal vacuums can create static or damage parts.
Assuming a surge protector keeps the computer on. It does not. Only a UPS does.
Throwing batteries in the trash. They are hazardous waste.
Working with the power still connected. Always unplug first, because standby power can still flow.
Check yourself
What does an ESD strap do?
It grounds the technician so static electricity drains away instead of damaging components.
Which device keeps a computer running during a power cut?
A UPS (uninterruptible power supply).
Where do you find handling and disposal advice for a chemical?
In its Safety Data Sheet (SDS).
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