Amazon will no longer allow the sale of USB cords that could potentially fry your gadgets.

In its list of banned items, updated this week, Amazon now includes "any USB-C cable or adapter product that is not compliant with standard specifications."

The new USB Type-C power cord standard is small, multipurpose, universal and reversible. They're capable of supplying way more power to a gadget than the old micro-USB cords, which for years have been the standard cords for smartphones.

If you charge your smartphone by plugging your USB-C cord into your laptop, a faulty cord could drain far more power from your laptop than your computer is designed to supply, destroying it -- and your smartphone -- in an instant.

Cheap power cords are nothing new. You can get cords that meet the old micro-USB standard for smartphones for a couple bucks on Amazon (AMZN). But cheap, poorly made USB-C cords are potentially dangerous.

The USB-C standards-setting group, the USB Implementers Forum, has been issuing a seal of approval for safe USB-C cords since they first appeared on the market last year. But Amazon had allowed non-certified cords on its website. Many physical stores, such as Staples (SPLS) and Best Buy (BBY), committed to selling only certified USB-C cords last year.

USB-C cords are supposed to recognize what kind of device they're drawing power from. If it senses it's plugged into a wall socket, it should crank up the juice. If it's plugged into a laptop, it should sip power.

That's not what happened to Google (GOOGL)engineer Benson Leung. While testing Surjtech's 3M USB-C cord, his $1,500 laptop turned into a very expensive piece of toast. The cord had been wired incorrectly,

Leung took it upon himself to review USB-C cords on Amazon to help prevent faulty cords from ruining someone else's day.

He praised Amazon's decision in a Google+ post this week.

"Really great news, but we all have to continue to be vigilant and call out any bad products we find on Amazon and other stores (both online and brick and mortar) as we find them," Leung said.

If you're an iPhone owner, you're safe for now. Lightning cords are certified by Apple (AAPL) (that's why they're so expensive), and Apple hasn't yet adopted the USB-C standard for its iPhones.