// Electrical

Electrical Safety - Basic Information

Why is it so important to work safely with or near electricity? The voltage of the electricity and the available electrical current in regular businesses and homes have enough power to cause death by electrocution.

Why is it so important to work safely with or near electricity?

context The voltage of the electricity and the available electrical current in regular businesses and homes have enough power to cause death by electrocution. Even changing a light bulb without unplugging the lamp can be hazardous because coming in contact with the "hot," "energized," or "live" part of the socket could kill a person.

What do I need to know about electricity?

What kinds of injuries result from electrical currents?

People are injured when they become part of the electrical circuit. Humans are more conductive than the earth (the ground we stand on) which means if there is no other easy path, electricity will try to flow through our bodies. There are four main types of injuries: electrocution (fatal), electric shock, burns, and secondary injuries (e.g., from a fall). These injuries can happen in various ways:

context Direct contact with exposed energized conductors or circuit parts. When electrical current travels through our bodies, it can interfere with the normal electrical signals between the brain and our muscles (e.g., the heart may stop beating properly, breathing may stop, or muscles may spasm). It can also cause burns to internal tissues along the path of the electric current while passing through the body. Burns to external tissues at the entry and exit points of the current can also occur.
context When the electricity arcs (jumps, or "arcs") from an exposed energized conductor or circuit part (e.g., overhead power lines) through a gas (such as air) to a person who is grounded (that would provide an alternative route to the ground for the electrical current).
context Thermal burns include burns from heat generated by an electric arc, and flame burns from materials that catch on fire from heating or ignition by electrical currents or an electric arc flash. Contact burns from being shocked can burn internal tissues while leaving only very small injuries on the outside of the skin.
context Thermal burns from the heat radiated from an electric arc flash. Ultraviolet (UV) and infrared (IR) light emitted from the arc flash can also cause damage to the eyes.
context An arc blast can include a potential pressure wave released from an arc flash. This wave can cause physical injuries, collapse your lungs, or create noise that can damage hearing.
context Muscle contractions, or a startle reaction, can cause a person to fall from a ladder, scaffold or aerial bucket. The fall can cause serious injuries.

What should I do if I think I am too close to overhead power lines?

Do not work close to power lines. Recommended distances vary by jurisdiction and/or utility companies. Check with both your jurisdiction and electrical utility company when working, driving, parking, or storing materials closer than 15 m (49 feet) to overhead power lines.

context If you must be close to power lines, you must first call your electrical utility company which will assist you.
context DO NOT get out of your vehicle.
context Call 911 and your local utility service for help.
context Wait for the electrical utility to come and they will tell you when it is safe to get out of your vehicle.
context Never try to rescue another person if you are not trained to do so.
context If you must leave the vehicle (e.g., your vehicle catches on fire), open the car door and prepare to jump by placing your feet on the door frame. Keep your arms close to your body. Jump with your feet together. Never touch the vehicle or equipment and the ground at the same time.
context Move away by shuffling your feet.
context Shuffle at least 10 metres away from your vehicle before you take a normal step.
context If your vehicle comes into contact with a power line:
context Do not enter an electrical power substation or other marked areas.

What are some general safety tips for working with or near electricity?

administrative Inspect portable cord-and-plug connected equipment, extension cords, power bars, charging stations, and electrical fittings for damage or wear before each use. Repair or replace damaged equipment immediately.
requirement Always tape extension cords to walls or floors when necessary. Do not use nails and staples as they can damage the cords and cause fire and shocks.
requirement Use extension cords or equipment that is rated for the level of amperage or wattage that you are using.
requirement Always use the correct size fuse. Replacing a fuse with one of a larger size can cause excessive currents in the wiring and possibly start a fire.
requirement Be aware that unusually warm or hot outlets or cords may be a sign that unsafe wiring conditions exist. Unplug any cords or extension cords from these outlets and do not use them until a qualified electrician has checked the wiring.
requirement Always use ladders made with non-conductive side rails (e.g., fibreglass) when working with or near electricity or power lines.
requirement Place halogen lights away from combustible materials such as cloths or curtains. Halogen lamps can become very hot and may be a fire hazard.
requirement The risk of electric shock is greater in areas that are wet or damp. Install Ground Fault Circuit Interrupters (GFCIs) as they will interrupt the electrical circuit before a current sufficient to cause death or serious injury occurs.
requirement Use a portable in-line Ground Fault Circuit Interrupter (GFCI) if you are not certain that the receptacle you are plugging your extension cord into is GFCI protected.
requirement Make sure that exposed receptacle boxes are made of non-conductive materials.
requirement Know where the panel and circuit breakers are located in case of an emergency.
requirement Label all circuit breakers and fuse boxes clearly. Each switch should be positively identified as to which outlet or appliance it is for.
requirement Do not use outlets or cords that have exposed wiring.
engineering Do not use portable cord-and-plug connected power tools if the guards are removed.
requirement Do not block access to panels and circuit breakers, or fuse boxes.
requirement Do not touch a person or electrical apparatus in the event of an electrical incident. Always disconnect the power source first.
requirement Make sure electrical tools and equipment have a certification marking from an accredited agency accepted by your jurisdiction (e.g., UL, ULC, CSA, ETL). Be careful when purchasing equipment from another country or online, as they may not be approved.
requirement Make sure only qualified individuals work on or perform maintenance on electrical equipment (e.g., electricians).

What are some tips for working with power tools?

Please also see our OSH Answers fact sheets on powered hand tools - electric tools, and welding - electrical safety.

requirement Switch all tools OFF before connecting them to a power supply.
requirement Disconnect and lockout the power supply before completing any maintenance work tasks or making adjustments.
requirement Ensure tools are properly grounded or double-insulated. The grounded equipment must have an approved 3-wire cord with a 3-prong plug, which should be plugged into a properly grounded 3-prong outlet.
requirement Before use, test all tools for effective grounding with a continuity tester or a Ground Fault Circuit Interrupter (GFCI).
requirement Do not bypass the on/off switch and operate the tools by connecting and disconnecting the power cord.
requirement Do not use electrical equipment in wet conditions or damp locations unless the equipment is connected to a GFCI.
requirement Do not clean tools with flammable or toxic solvents.
requirement Do not operate tools in an area containing explosive vapours or gases, unless they are intrinsically safe and only if you follow the manufacturer's guidelines.
requirement If a power tool is battery-operated, make sure it is charged safely.

What are some tips for working with power cords and extension cords?

requirement Keep power cords and extension cords clear of tools during use.
requirement Confirm that the length and gauge of the extension cord are appropriate for the work, and make sure the cords are straight and not twisted or rolled up before use.
elimination Suspend extension cords temporarily during use over aisles or work areas, or keep them protected and secured down to eliminate tripping hazards.
requirement Replace open front plugs with dead front plugs. Dead front plugs are sealed and present less danger of shock or short circuit.
requirement Do not use light-duty extension cords in a non-residential situation.
requirement Do not carry or lift up electrical equipment by the power cord.
requirement Do not tie cords in tight knots. Knots can cause short circuits and shocks. Loop the cords or use a twist lock plug.
requirement Do not use extension cords as permanent wiring, and make sure they are not overloaded and only used for low-voltage equipment.

What is a Ground Fault Circuit Interrupter (GFCI)?

context A Class A Ground Fault Circuit Interrupter (GFCI) works by detecting any loss of electrical current in a circuit (e.g., it will trip at a maximum of 6mA). When a loss is detected, the GFCI turns the electricity off before severe injuries or electrocution can occur. A painful non-fatal shock may occur during the time that it takes for the GFCI to cut off the electricity so it is important to use the GFCI as an extra protective measure rather than a replacement for safe work practices.
context GFCI wall outlets can be installed in place of standard outlets to protect against electrocution for just that outlet, or a series of outlets in the same branch circuit. A GFCI Circuit Breaker can be installed on some circuit breaker electrical panels to protect an entire branch circuit. Portable in-line plug-in GFCIs can be plugged into wall outlets where appliances will be used.

When and how do I test the Ground Fault Circuit Interrupter (GFCI)?

context It is important that you follow the manufacturer's instructions with respect to the use of a GFCI. Test permanently wired GFCIs monthly, and portable devices before each use. Use a GFCI tester. You may also test by pressing the "test" and "reset" buttons. Plug a "night light" or lamp into the GFCI-protected wall outlet (the light should turn on), then press the "TEST" button on the GFCI. If the GFCI is working properly, the light should go out. If not, have the GFCI repaired or replaced. Press the "RESET" button on the GFCI to restore power.
context Contact a qualified electrician if you are unsure or to correct any wiring errors.

What is a sample checklist for basic electrical safety?

Inspect Cords and Plugs

requirement Check extension cords and plugs daily. Do not use, and discard cords and plugs if they are worn or damaged.
requirement Have any extension cord that feels more than comfortably warm replaced or checked by an electrician.
requirement Have GFCIs installed in areas that may get wet or humid (e.g., washrooms, kitchens, laundry facilities, near hoses or other water sources).

Eliminate Octopus Connections

requirement Do not plug several items or multiple extension cords into one outlet.
requirement Pull the plug, not the cord.
requirement Do not disconnect the power supply by pulling or jerking the cord from the outlet. Pulling the cord causes wear and may cause a shock.

Never Break OFF the Third Prong on a Plug

requirement Replace broken 3-prong plugs and make sure the third prong is properly grounded.

Never Use Extension Cords as Permanent Wiring

requirement Use extension cords only to temporarily supply power to an area that does not have a power outlet.
requirement Keep extension cords away from heat, water and oil. They can damage the insulation and cause a shock.
requirement Do not allow vehicles to pass over unprotected extension cords. Extension cords should be placed in a protective wireway, conduit, pipe, or protected by placing planks alongside them.

What are the laws for electrical safety?

In Canada, each jurisdiction (provincial, territorial, and federal) is responsible for developing and enforcing legislation governing electrical safety, which are made up of codes and standards. The Canadian Electrical Code (CSA C22.1) serves as the standard for the safe installation of electrical wiring and equipment across Canada. All provinces, territories and the federal jurisdiction reference an edition of the Canadian Electrical Code in their legislation with a schedule of changes that amends the code for local conditions. These amendments tend to have both administrative and technical content particular to the region. The Code provides a standard for the safe installation and maintenance of electrical equipment to prevent fire and shock hazards. Fire codes and building codes will also include requirements related to electrical safety. Occupational health and safety legislation may also outline requirements related to electrical safety, including how to control hazardous energy (e.g., lockout/tag out) and what personal protective equipment is needed.