After the incident where a Chinese woman died while charging her iPhone 5, Apple has started warning its Chinese customers to stay away from cheap non-genuine iPhone and iPad chargers. Apple launched a page on its website recommending and demonstrating the official chargers for the their iPhone and iPad models.
This is what the page translate to:
Apple always put the user’s safety first, so all of our products are subject to stringent safety and reliability testing, and designed to meet government safety standards around the world, including for the iPhone and iPad USB power adapter.
This overview will help you identify genuine Apple USB power adapter. When you need to charge the iPhone or iPad, we recommend that you use the random standard USB power adapter and USB cable. These adapters and cables are also available separately from Apple and Apple Authorized Resellers.
So if you want to stay safe, don’t be cheap and buy an official charger for your iOS device.
(Source: Apple China)