Extension cords are convenient ways to provide power to portable equipment' However, they are often

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Fact SheetDeveloped by Safety Office, SCARNG,
Columbia, SC
Electrical Extension Cords

• Extension cords are convenient ways to provide
  power to portable equipment.  However, they are
  often misused, resulting in injuries and
  expensive OSHA fines. 
• Extension cords are intended only for temporary
  use with portable equipment.  Extension cords may
  only be used for temporary uses such as floor
  fans, computer or projector hook-up in a
  conference room for single use, or for holiday
  needs. 
• OSHA regulations prohibit the following uses of
  extension cords
• as a substitute for fixed wiring (i.e. permanent)
• when run through holes in walls, ceilings, or
  floors
• when run through doorways or windows
• when attached to building surfaces
• when concealed by walls, ceiling, or floors
• For more information, consult 29 CFR 1910.305

Although it is tempting to use an extension cord
to power an office computer, such use is not
approved except for temporary use of a computer
such as in a conference room for a presentation.