In my years as a safety professional, I have performed 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.
According to OSHA, electrocution is the second leading cause of death in the construction industry. Approximately 350 electrical-related fatalities occur each year in the U.S. alone. Electricity is widely recognized as dangerous, so why are the electrocution rates so high? More importantly, what can we do to reduce this rate?
Perhaps electricity is so common to us that it does not receive the respect and attention that it deserves. When any hazard is recognized in the workplace, control measures must be established to keep workers safe. Following are the five main causes of injuries from electricity and how to avoid these injuries.
According to the U. S. Department of Labor, the following hazards are the most frequent cause of electrical injuries:
- Contact with power lines
- Lack of ground-fault protection
- Path to ground missing or discontinuous
- Equipment not used in manner prescribed
- Improper use of extension or flexible cords
1: Contact with Powerlines
Overhead and buried powerlines can be hazardous, as they can carry extremely high voltage. Some lines carry over 700,000 volts! Although fatal electrocution is the main hazard, severe burns and falling from elevated levels can also be concerns.
Over 100 work related fatalities occur each year due to contact with overhead powerlines. What typically happens is a piece of equipment the worker is using, such as a crane or ladder, comes into contact with the powerline, which results in a shock being delivered to the worker.
In July 2005, four adult scout leaders were killed when a tent pole they were setting up came into contact with an overhead powerline.
How to Avoid this Hazard:
This is one subject where complacency can get you killed. When work is taking place anywhere outside, the placement of powerlines needs to be examined.
Stay at least ten feet away from overhead powerlines at all times, this distance includes equipment. Be sure to use non-conductive wood or fiberglass ladders when working near powerlines.
Ensure that no digging is completed without first checking for underground powerlines. Look for posts and signs designating underground lines. Additionally, always confirm it is safe to dig by first contacting your utility company. If work must be done near a powerline, contact the utility company first. It may be possible to de-energize the line or come up with a guard in an effort to increase worker safety.
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2: Lack of 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 workers' body.
How to Avoid This Hazard:
Always inspect equipment and power tools prior to each use. Ensure this becomes part of your standard work routine. Place a warning tag on any equipment that is unsafe and take it out of use until fixed. For more information on lockout / tagout procedures, check out Understanding Lockout / Tagout Safety.
Only use power tools according to their manufacturers intended use and instructions. Use CFCIs (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 expose the worker to electrical shock. Even with good equipment, this can occur due to extreme work conditions or rough treatment of 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. If the case is the latter, have a certified professional inspect the system as required.
Inspect all electrical equipment before use, and be sure to remove defective equipment. 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.
As with any type of equipment, only use equipment in the manner prescribed by the manufacturer.
4: Equipment Not Used in Manner Prescribed
Let’s face it, any time we use a tool or equipment for purposes it was not meant for, we are quite possibly voiding all safety features. We may inadvertently damage equipment and endanger other workers or ourselves.
How to Avoid the Hazard:
Use only equipment that is approved by your regulatory safety agency 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, the Occupational Safety & Health Administration (OSHA) and the National Fire Protection Association, each year electric extension cords account for 3,300 residential fires killing and injuring over 300 people. The most frequent causes of these fires are short circuits in the cord, overloading, damage or misuse. 4,000 cord related injuries are treated in hospital emergency rooms each year. About half of these injuries are from people tripping over the cord.
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
- Ensure the cord is not a trip hazard
Promote Electrical Safety
By promoting electrical safety at work, you will also be helping keep employees safe at home. As a safety trainer, I love those topics that have home benefits as well as an at-work application.
A proactive approach to electrical safety is important to all. 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.
When in doubt, consult a certified electrician. Remember, there is almost one electrical fatality per day. I urge you to take a proactive approach to electrical safety as part of your safety management system.