It's not a case of ethernet not being very safe, it's a case of it not being Intrinsically Safe. This is a technical term, and describes the failsafe protections built into the hardware layer.

To achieve Intrinsic Safety, an engineer needs to consider things like maximum voltage and current (power) and things like current and voltage clamping in short and open circuit situations, EMF fields, things like the physical separation between cabling, restraining methods, all sorts of other things.

It has been a while since I worked in this area so I don't remember what the specifics are, but it's still quite simple: Ethernet is not intrinsically safe. Operating it near petroleum vapours is operating it in an explosive environment. (IIRC, "Class One Zone One"- to get any more dangerous, you're designing for things that are immersed in the stuff).

Installing ethernet near your filler cap may not be enough to immediately cause an explosion. However, it may be enough to be a contributing factor. And you don't know, because you don't know what the specs are. Just think what might happen if you've got ethernet installed, it's a hot day, you've got half a tank of gas, you are connecting the cable and then your mobile phone on your hip rings. Think about it now, because you won't be doing much more thinking if bits of you are sailing through the air in different directions...

Perhaps I'm just funny this way. But I'm not willing to take the chance.

Cheers
Jon

PS If anyone *does* decide to do this, can they please remove their empeg first and bequeath it to me in their will? You'll never know you're missing it ;-)