Are non-Apple lightning cables and power transformers safe to use?

I need to buy an Apple 12W USB Power Adapter for my iPhone 5.

In eBay you can find replicas for one third of the price. Do you know if these can ruin your phone? I am more cautious about a third party adapter than just a simple cable, so if you could address if a third party cable were OK or more safe to use with an Apple Power Adapter.

Don't these accessories come standard with your iPhone 5 when you buy one?

I was travelling across China a few years ago and I bought a dozen of those 'cheap' adapters. They still charge my iPad and iPhone. So they do work and at first sight, they don't cause any harm to my devices.

But bare in mind Apple's adapters are probably the most safe ones to use. It makes sense a 19$ adapter provide more power, safety and guarantees then a 0,19$ adapter from eBay, DealExtreme,... There are even people claiming they will harm your iPhone (or your house).

Ken Shirrif has compared like 12 adapters and his findings are written in his blog.

To give a short answer, I have no bad experience in using "fake" adapters (which is no guarantee or reference at all!), but if you want to play safe, just buy the real stuff :)

Replica Lightning to USB:

This is completely safe yes. Personally I only use replicas at home and have not experienced any problems with it. Usually the price is more than half of what the original lightning adapter is.

Replica cables:

Only CONS with replica cables is the quality of the termination at the ends of the cables. But as a PRO you can buy two-maybe three replicas in the price of one original. Just keep in mind to pull out the cable holding the plastic piece on both ends instead of pulling directly on the cable and you will be fine using those.

Replica Power Adapters (USB):

For the Power adapter itself (USB) have a look at the answer here. Personally i dont recommend those. Mostly for the quality Apple have versus the replicas. Feels safer to use the original in this matter.