Seems like a big problem with vaping is that it is - in a certain way - a "medical device", in the sense that it is distributing a chemical by way of an electrical device.
The electrical device, the composition of the chemical and I guess even the quality of the chamber holding the chemical are all factors with a lot of potential variability, as opposed to a cigarette, which is much more simple in its design, and thus easier in terms of guranteeing a certain quality (there are roll-ups, sure, but most people wouldn't trust a "packaged-from-a-store box of roll ups").
So to solve this you basically have three ways of going about it:
* Heavily regulate the private sector creating them, ensuring standardization of quality similar to how there are millions of plastic-products, but you can generally trust it if it's labeled as "food grade" (to take one, admittedly odd example; it's just been on my mind)
* Doing the same, but nationalizing it, allowing an even higher level of quality assurance because of governmental transparency. This one is a little bonkers from an american perspective, and probably not a super-great idea in general, but alcohol-sale is essentially nationalized in Sweden, so it's not unheard of. If marijuana ever becomes a legal thing in Sweden, it would most likely be through a similarly nationalized outfit (I hope).
* Ban all of it, because figuring out standardization that essentially ensures medical-grade excellence within a new field like vaping is probably both very expensive and hard.
I don't vape, but also don't really care if other people want to. But if they want to, I feel like society has to ensure that they do it as safe as possible.
But for the reasons I've layed out (sorta flimsily, I guess), to make that happen you basically need very strict regulation of every aspect of both the device and the chemical components (which further need to be in tamper-proof/tamper-resistant cartridge that makes it easier for consumers to tell if what they are buying is legitimate).
Because of how vaping works, it really becomes a new class of device, that most closely resembles a medical device. Not only does this mean a need for better documentation and long-term research, but it absolutely requires stringent quality control of each part of the device (with tampering/black-market replacement-attempts in mind, too).
At least if we're going to be all "we live in a society" about it, and not throw away human health-concerns just because it's a new gadget.