In my years as a safety professional, I have performed many accident investigations involving electricity. Luckily, all of them have been minor, usually involving an exposed wire zapping someone. I always used these types of incidents as opportunities to stress electrical safety.

Electrocution is one of the leading causes of fatalities in the construction industry. 134 electrocution fatalities were reported in the United States in 2015. If electricity is widely recognized as dangerous, why are the electrocution rates so high? More importantly, what can we do to reduce this rate?

Perhaps electricity is so common that we don't give it the respect and attention it deserves. But when any hazard is recognized in the workplace, control measures must be established to keep workers safe.

(Learn about The Hierarchy of Hazard Controls.)

The following are the five main causes of injuries from electricity and some advice on how to avoid these injuries.

1. Contact with Power Lines

Overhead and buried power lines can carry extremely high voltage, with some lines carrying over 700,000 volts!

Although fatal electrocution is the main hazard, severe burns and falling from elevated levels can also be concerns.

What typically happens is that a piece of equipment the worker is using, such as a crane or ladder, comes into contact with the power line, which delivers a shock to the worker.

How to Avoid This Hazard

  • When working outside, observe and keep in mind the placement of power lines.
  • Stay at least ten feet away from overhead power lines at all times. Observe this same distance with equipment.
  • Use non-conductive wood or fiberglass ladders when working near power lines.
  • Ensure that no digging is undertaken without first checking for underground power lines. Look for posts and signs designating underground lines. Always confirm it is safe to dig by contacting your utility company.
  • If work must be done near a power line, contact the utility company first. It may be possible to de-energize the line or come up with a guard to increase worker safety.

2. No Ground-Fault Protection

This type of electrical hazard is often created due to excessive wear on power tools and equipment. This can cause breaks in insulation and exposed wire.

Without ground-fault protection, contact can send electricity through a worker's body.

How to Avoid This Hazard

  • Always inspect equipment and power tools prior to each use. Make this part of your standard work routine.
  • Place a warning tag on any equipment that is unsafe and take it out of use until fixed.
  • Only use power tools according to their manufacturers intended use and instructions.
  • Use GFCIs (ground-fault circuit interrupters) on all 120-volt, single-phase, 15- and 20-ampere receptacles.

3. Pass to Ground is Missing or Discontinuous

This occurs when the power supply for electrical equipment is not properly grounded, or the path has been broken. This can even happen with good equipment, either due to extreme work conditions or rough treatment of the equipment.

Electrical grounding is where a point in a circuit is at zero voltage. A broken electrical cord or damaged power tool can cause a lack of proper grounding.

How to Avoid This Hazard

  • Be sure to ground all power supply systems, electrical circuits, and electrical equipment.
  • Frequently inspect electrical systems to ensure that the path to ground is continuous. Electrical systems can be as simple as batteries powering a flashlight to as complex as those in a jet airliner. With more complex systems, you may need to get a certified professional to inspect the system.
  • Never remove ground prongs from power cords or extension cords. Use double-insulated tools and equipment.
  • Ground all exposed metal parts of equipment. Ground metal parts of non-electrical equipment, as specified by the OSHA or your governing regulatory agency.

4. Equipment Not Used in Manner Prescribed

Let’s face it, any time we use a tool or equipment for purposes it wasn't meant for, we are quite possibly voiding all of its safety features. We may inadvertently damage equipment and endanger other workers or ourselves.

How to Avoid This Hazard

  • Use only equipment approved by regulatory safety agencies, including OSHA.
  • Always use equipment in accordance with the manufacturer’s instructions and never modify cords or the equipment in any way.
  • If equipment or cords have been fabricated in your shop, ensure that they meet all regulatory safety standards.

5. Improper Use of Extension or Flexible Cords

It is easy to have wear and tear on all types of electrical cords with normal use. This can expose and loosen wires, which may create a shock hazard. Cords that have been modified increase the chance of shock unless they meet all safety agency standards.

According to the Consumer Product Safety Commission, each year electric extension cords account for 4,600 residential fires killing and injuring about 300 people. The most frequent causes of these fires are short circuits in the cord, overloading, damage or misuse.

How to Avoid This Hazard

  • Only use factory-assembled cord sets.
  • Only use three-wire type extension cords.
  • Only use the proper extension cord for the designated use. Cords are rated in many different ways. OSHA requires three-wire cords designed for hard or extra-hard usage. Hard-service cords are marked with letters including S, SE, SO, ST.
  • Remove cords from receptacles by pulling on the plugs, not the cords.
  • Regularly audit all extension and flexible cords for damage. Make this a proactive, scheduled activity. Damaged cords and those not properly rated must be taken out of service immediately.

(Learn more about Power and Extension Cords.)

Promote Electrical Safety

We use electricity daily and complacency is to be expected, but this must be countered by safe work habits that are intentionally designed to prevent electrical hazards. Ensure that your standard work instructions include electrical safety as it pertains to your work environment.

(Find out How to Use Standard Work Instructions to Improve Workplace Safety.)

When in doubt, consult a certified electrician. Remember, there is almost one electrical fatality every day. I urge you to take a proactive approach to electrical safety as part of your safety management system.