Evaluating Your Risk
After you recognize a hazard, your next step is to evaluate your risk
from the hazard. The closer you work to the "danger zone," the more likely you'll be exposed to the electrical hazard. For instance, exposed wires should be recognized as
a hazard. If the exposed wires are 15 feet off the ground, you're not close to the danger zone so the risk
is low. However, if you are going to be working on a roof near those
same wires, your risk is high. The risk of shock is greater if you
will be carrying metal conduit that could touch the exposed wires.
It's important that as you work throughout the day, you must constantly evaluate your risk.
Another factor increasing your risk of injury is working around combinations of hazards. Improper
grounding and a damaged tool greatly increase your risk. Wet conditions
combined with other hazards also increase your risk. You will need
to make decisions about the nature of hazards in order to evaluate
your risk and do the right thing to remain safe.
There may be important clues that electrical hazards
exist. For example, if a GFCI keeps tripping while you are using a
power tool, that's a clue that there is a problem. Don't keep resetting the GFCI and
continue to work. You must evaluate the "clue" and decide
what action should be taken to control the hazard.
Any of these conditions,
or "clues," tells you something important: there is
a risk of fire and electrical shock. The equipment or tools
involved must be avoided. You will frequently be caught in situations
where you need to decide if these clues are present. A maintenance
electrician, supervisor, or instructor needs to be called if
there are signs of overload and you are not sure of the degree
of risk. Ask for help whenever you are not sure what to do.
By asking for help, you will protect yourself and others.
An 18-year-old male worker had just completed mopping the floor 10 minutes earlier and was plugging a toaster into a floor outlet when he received a shock. The restaurant manager and another employee heard the victim scream and investigated. The victim was found with one hand on the plug and the other hand grasping the metal receptacle box. His face was pressed against the top of the outlet.
By the time the circuit was turned off, the victim had been exposed to the current for 3 to 8 minutes. The manager and the employee left the victim to unlock the front door and call for help. Another employee found that the victim no longer had a pulse. The employee began administering CPR, which was continued by the rescue squad for 90 minutes, but unfortunately the victim was dead on arrival at a local hospital.
The investigation showed that the victim's hand slipped forward when he was plugging in the toaster. His index finger made contact with an energized prong in the plug. His other hand was on the metal receptacle box, which was grounded. Current entered his body through his index finger, flowed across his chest, and exited through the other hand, which was in contact with the grounded receptacle.
To prevent death or injury, you must recognize hazards and take the right action.
- If the circuit had been equipped with a GFCI, the current would have been shut off before injury occurred.
- The recent mopping increased the risk of electrocution. Never work in damp or wet areas!
- Know the location of circuit breakers for your work area.
Conditions that Point to Electrical Hazards
There are a number of other conditions that indicate an electrical hazard.
- Tripped circuit breakers and blown fuses show that
too much current is flowing in a circuit. This condition could be
due to several factors, such as malfunctioning equipment or a short
between conductors. You need to determine the cause in order to
control the hazard.
- An electrical tool, appliance, wire, or connection
that feels warm may indicate too much current in the circuit or
equipment. You need to evaluate the situation and determine your
- An extension cord that feels warm may indicate too
much current for the wire size of the cord. You must decide when
action needs to be taken.
- A cable, fuse box, or junction box that feels warm
may indicate too much current in the circuits.
- A burning odor may indicate overheated insulation.
- Worn, frayed, or damaged insulation around any wire
or other conductor is an electrical hazard because the conductors
could be exposed. Contact with an exposed wire could cause a shock.
Damaged insulation could cause a short, leading to arcing or a fire.
Inspect all insulation for scrapes and breaks. You need to evaluate
the seriousness of any damage you find and decide how to deal with
- A GFCI that trips indicates there is current leakage
from the circuit. First, you must decide the probable cause of the
leakage by recognizing any contributing hazards. Then, you must
decide what action needs to be taken.
A 20-year-old male laborer was carrying a 20-foot piece of iron from a welding shop to an outside storage rack. As he was turning a corner near a bank of electrical transformers, the top end of the piece of iron struck an uninsulated supply wire at the top of a transformer. Although the transformers were surrounded by a 6-foot fence, they were about 3 feet taller than the fence enclosure. Each transformer carried 4,160 volts.
When the iron hit the supply wire, the laborer was electrocuted. A forklift operator heard the iron drop to the ground at about 8:46 a.m. and found the victim 5 minutes later. He was pronounced dead on arrival at a local hospital.
According to OSHA, this fatality would not have occurred if:
- The enclosure around the fence was too low. The fence should have been at least 8 feet tall.
- The company in this case did not offer any formal safety training to its workers. All employers should develop safety and health training programs so their employees know how to recognize and avoid life-threatening hazards.