2020 Update

Although nearly a year old, all of the information in this article is still relevant. It is important to know if your extension cords are a potential fire hazard; scroll down to find out more. 

Extension cords are so convenient that that they’re easy to misuse, something that can turn a handy piece of household equipment into a major safety hazard. This article will help inform you whether you have a power extension cord fire hazard or not.

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    Extension Cord Fire Hazard

    “Extension cords are for temporary use, but a lot of people plug them in various places and they stay there,” says John Drengenberg, consumer safety director at UL, which tests and rates electrical cords and other products. “We know you might have to run a cord under your couch to connect to a lamp on an end table. It’s when the cord gets covered by a carpet or a rug that the problems begin.”

    It’s just a matter of time, Drengenberg says, until that cord becomes a fire hazard.

    Cords under rugs can overheat, especially when the wires inside begin to break down because people are trampling on them. This reduces the ability of the cord to transmit current, causing it to get hot. When are such cords most likely to catch on fire? “Statistics show it usually happens in the middle of the night,” Drengenberg says.

    Why do people snake cords under rugs and through doorways, anyway? Cost and convenience are the usual reasons. “It’s expensive to have an electrician come into your house and create more wall outlets,” Drengenberg says. “Older houses might have just one outlet in a bedroom. Today people have televisions in their bedroom, and they’re charging mobile devices and sitting in bed with their laptops plugged in. So that easy solution is to plug in an extension cord.”

    However, it’s not a long-term solution. “If you’re using a lot of power extension cords in your home, it’s time to call an electrician and get more outlets put in,” says Drengenberg.

    Even when extension cords are put to their proper use, such as for temporary holiday lighting, people often forget basic safety precautions.

    “Some homes don’t have outdoor receptacles, so people run the extension cords for their decorating lights through a door or out the window,” Drengenberg says. “In certain parts of the country when it’s very cold that time of year, people close windows and doors as tight as they can, which squashes the cord and starts breaking the wires inside. Fewer wires, more heat,” which translates into a fire hazard.

    Bright pink extension cords that are wrapped around each other to form a circle.

    Here are a few basic safety precautions, courtesy of Drengenberg, home insurance experts and the Electrical Safety Foundation International:

    • Never run a power extension cord under a rug, through a wall, over a beam or through a doorway or window.
    • Avoid using coiled extension cords.
    • Don’t tack extension cords to the wall with nails or staples.  Besides creating another potential fire hazard, “you might give yourself a good jolt of electricity,” Drengenberg says.
    • Plug all kitchen appliances, such as microwaves, coffee machines and toasters, into wall sockets rather than an extension cord, advise home and rental insurance experts.
    • If you have to use a temporary extension cord, plug in only one appliance per cord, advises the Electrical Safety Foundation International.
    • If an extension cord feels unusually warm to the touch, unplug it from the wall outlet and buy a new one.
    • When buying a cord, make sure it’s UL-certified and the right cord for the job. “Folks at the hardware store will know how much power a cord will draw for a particular use, and they can guide you to the right cord to buy,” says Drengenberg.
    • Only use a cord designed for outdoor use for your outdoor power tools and equipment. To save money, you can buy extension cords rated for outdoor use for your home, since these can be used safely indoors. Do NOT use indoor cords outside, though, because they’re not designed to repel moisture — nor are they typically rated for the higher power requirements of outdoor equipment.
    • Always protect extension cords used outdoors or in a wet location with a ground fault circuit protector even if it is an outdoor extension cord.
    • If you do damage your extension cord, don’t try to slice, tape or otherwise repair it. Instead, get a new one.
    • Whatever device you plug an power extension cord into, the cord should be long enough to reach a wall outlet. Don’t daisy-chain two or more cords together, Drengenberg says, because they’re more likely to snag on something, overheat, or be exposed to dampness and water at the connection point between two cords.

    A white extension cord connected to a lamp hangs from a bedside table that's next to a bed with a bright white bedspread.

    Finally, know when to toss out your old extension cords. Here’s when to throw them away:

    • No certification or rating label appears on the cord
    • A two- or three-conductor cord lacks the minimum conductor size of 16 AWG (American Wire Gauge) wire, information that you can find on the cord’s label
    • The cord doesn’t have a three-prong plug and connector for modern wall receptacles
    • The cord’s plug has same-size blades instead of modern polarized plugs that insert into an outlet one way only
    • The wires have cracked insulation or exposed wiring
    • The cord and plug have a loose connection

    Steve Evans, MA, is an award-winning journalist with more than 20 years’ experience in daily news and business journalism. Among other jobs, he has served as managing editor of the Central Virginia Newspaper Group, as a staff writer for the Richmond Times-Dispatch and as a senior writer for SNL Financial and a roving reporter for MoneyGeek.com. He has written widely about consumer finance topics, including comics and other collectibles.