Sorry you got bushwacked by your inlaw.
There's a guy at work, a vaper, that insists that vaping is carcinogenic. I try to get him to stop with that. That if it is it is on the order of the carcinogens in nicotine patches, etc.; that there do need to be more studies; that there is the possibility of formaldehyde being present in some juices at high temps, but again at levels far below that of cigarettes, but he just will not knock it off.
Not all the stupid is on the other side. I freely admit that I am not in possession of all the currently known facts regarding vaping. But then: who is? Not enough is known at this point.
Here's a blog covering some of the recent "facts" trundled out to go after e-liquid and some of the recommendations that have been coming out of the EU from researchers who are taking the time to try and ascertain the actual dangers involved in handling or ingesting eliquid.
http://blog.rursus.de/2013/12/attempting-to-commit-suicide-with-e-liquids-witless/
BTW, The suicide in this country? Someone correct me if I'm wrong, but I thought that it was pure nicotine, not eliquid, involved in that one. Anyone know for sure?