Arhgh theres actually two types of ceramic in use, these types of ceramic - The kind used by Vaporesso and a couple of other companies are the porous wick through type - I've never been keen on them, power hungry and not terribly well made.
The other type are the "CVU" heating chip used by the Guo Vapes Altus, they are of a much higher grade and use a Tungsten trace embedded in a non porous ceramic It doesnt wick the juice - it merely works as a long life coil that heats a wick wrapped around it. As far as I know they are safe - and are used for laborotary grade equipment - It's just a shame Guo Vapes are a bunch of Knob jockeys - Who when asked to sell me a replacement CVU chip for the one I damaged, were perfectly willing to send one - until they found out I was not in the US, at which point they couldn't even be bothered to reply to my Emails...