Extension cords should only be used when necessary and only for temporary use. If you have more than a few extension cords powering equipment in your lab, it is probably time to call an electrician to install additional strategically placed outlets or rearrange equipment.

Likewise, if you have any cords running through walls, up through the ceiling and down somewhere else, an electrician is definitely required.

According to the Consumer Product Safety Commission, electrical cords and plugs were involved in about 7,100 fires resulting in 120 deaths in 1996. In 1997 more than 12,000 people were treated for electrical shocks and burns. About 2500 of them were treated for injuries stemming from extension cords. With a little care and some precautions these conveyors of power can be used safely.

From: Power through the People - A Shocking Tale by The Safety Guys