S AFETY ALERT | OCTOBER 2014
Extension Cords and
Power Strip Safety
Extension cords and power strips are a convenient
way to get electricity to where it is needed when
no electrical outlet is nearby. However, improper
use of extension cords and power strips can cause
fires, electrical shocks or burns and equipment
damage. According to the U.S. Consumer Product
Safety Commission (CPSC), electricity causes
more than 40,000 fires every year in the United
States, killing more than 750 people and causing
more than one billion dollars in property damage.
Power strips and extension cords have been
identified as a leading cause of electrical fires in
the home. Every six minutes there is an extension
cord-related electrical fire in the United States.
Extension cords and power strips can also create a
tripping hazard. Every year, an estimated 2,000
people trip over extension cords and suffer injuries
that are serious enough to require a visit to a
hospital emergency room. Injuries include such
things as lacerations, contusions, sprains and
fractures.
Extension cords are for temporary use only,
and yet the majority of homes and offices have at
least one extension cord plugged in and left in
place. Continual use can cause the insulation to
rapidly deteriorate, creating a dangerous shock
and fire hazard. In addition to the same safety tips
that apply to power cords, keep the following
principles in mind when using extension cords.
Ÿ Extension cords should only be used on a
temporary basis; they are not intended as
permanent wiring.
Ÿ Make sure extension cords are properly rated
for their intended use, indoor or outdoor, and
meet or exceed the power needs of the
appliance or tool being plugged into it.
Power strips give us the ability to plug more
products into the same outlet, which can be a help
but also a hindrance to safety if used
inappropriately. Power strips and surge
suppressors don't provide more power to a
location, just more access to the same limited
capacity of the circuit into which it is connected.
The circuit likely also still serves a variety of other
outlets and fixtures in addition to the multiple
electrical items you might be serving with the
power strip. In addition to the tips above, keep
these safety principles in mind when using power
strips and surge suppressors.
Ÿ Be sure you are not overloading the circuit.
Know the capacity of the circuit and the power
requirements of all the electrical items plugged
into the power strip and into all the other
outlets on the circuit, as well as the light
fixtures on the circuit.
Ÿ Understand that a surge suppressor only
protects the items plugged into it, not back
along the circuit into which it is connected.
Ÿ Surge suppressors can manage the small
surges and spikes sometimes generated by the
turning on and off of appliances. They may
even protect against a large surge generated
from outside sources like lightning or problems
FOR ADDITIONAL INFORMATION, PLEASE CONTACT:
tandmassociates.com
MARK WORTHINGTON, CHMM
GROUP MANAGER, ENVIRONMENTAL HYGIENE
732.676.1700 | MWORTHINGTON@TANDMASSOCIATES.COM
T&M SAFETY ALERT
PAGE | 2
along the power lines to the office or house. In
the event of a large surge or spike, the surge
suppressor is a one-time-use protector and will
likely have to be replaced.
Ÿ Consider purchasing surge suppressors with
cable and phone jacks to provide the same
protection to your phone, fax, computer
modem, and television.
Ÿ Not all power strips are surge suppressors and
not all surge suppressors can handle the same
load and events. Be sure the equipment you
buy matches your needs.
Determining Power Strip Capacity
Extension cords and power strips are not intended
for high power loads, such as microwave ovens,
refrigerators or space heaters, according to the
Occupational Safety and Health Administration
(OSHA). Power strips are for use with low-powered
loads such as computers, peripherals and audio or
visual equipment.
All appliances indicate how much wattage is
consumed when operated. That rating can be
found on the appliance itself and often within the
use and care booklet that accompanies the
product. Other appliances will indicate power
usage in amps, rather than watts.
Quick Tip
If your appliance indicates that it uses 5 amps at
125 volts, then its wattage rating is 625 watts (5
amps X 125 watts).
If you are going to use extension cords, power
strips or surge protectors with two or more items,
you must add together the wattage rating for all
items used on the cord. The total of those wattage
ratings will help you determine which gauge size
you will need.
Some common electric devices in watts:
Hair Dryer = 1,600
Portable Heater = 1,500
Portable Fan = 150
Television = 150
Computer = 150
Microwave = 700-1000
Toaster Oven = 1000-1500
Do the Math
Determine all the electrical items plugged into the
extension cord, power strip or surge protector.
Determine the power requirements for each item,
either in amps or watts, and add up all the power
requirements. Now locate the capacity of the
extension cord, power strip, or surge protector you
are using. The total you calculated should not
exceed 80 percent of the rated capacity of the
extension cord, power strip, or surge protector.
Do not daisy chain power strips with extension
cords. In other words, do not hook several
extension cords together to energize a power strip
located far away from an electrical outlet.
Electrical resistance increases with cord length
and can cause overheating, leading to a fire or
equipment failure. In addition, hooking several
power strips together can result in an overload,
which can also cause a fire, trip a circuit breaker
or cause a loss of power to the electrical
equipment plugged into the power strips.
A heavy reliance on extension cords and power
strips may be an indication that you have too few
outlets to address your needs. When there are not
enough outlets to supply occupants' needs, one
solution is to request the installation of additional
outlets.
In summary, extension cords are for temporary use
only and really have no place in an office area.
Power strips allow multiple devices to be
powered; however, they should be used sparingly
and temporarily with small appliances and
electronics, rather than as a substitute for a
permanent wall receptacles.
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