so can your phone, especially the ones with large batteries. its a known safety issue with lithium based rechargeable batteries. Also, less strict quality control with a ****ton of the cheap chinese drivel thats put out is definitely a risk. but on the other hand, i leave mine charging overnight and dont give a crap...
i've been using them for more than 2 years now and was prompted by horrid prices of cigs in Ireland, 9€/pack, coming from a country where tobacco taxes arent insane yet and a pack was something like 3€, it was "do i get an ecig kit for 30€ + 2-3€/week or do i pay 9€/day for the next 3 months" so yeah.
i've used ****tons of different products over the years and settled on stuff that some people might find "excessively large", which is basically 2 2600mah batteries with vaporizers with tanks of 5ml capacity. also, a ****ton of DIY stuff involved so yeah.
i personally go through roughly 75-80ml of e-liquid a week and i consider myself a heavy user of these. i never looked at it as a "something to help me quit".
i never intended to quit, nor do i have any wish to do so. this is just cheaper and stinks a ****ton less.
one thing i did get over was to go from 20mg cigs to 6mg/ml e-liquid and going to sweeter, non-tobacco flavors. for me, it was always about the smoke and the act of smoking. if what goes into me is less filled with crap and i dont have to cough up stinky phlegm every morning, yay.
also, one thing i know i've saved is tons and tons of money.
after two years of vaping and using and buying all sorts of crap, i spent roughly 800€ total on e-cigs and liquids. i was a 2 packs a day smoker. if i was smoking cigs, i would've spent roughly 4380€. probably more because i think cig prices went up to 4€/pack or so here.
Also, the content of the e-liquids is Propylen Glycol + Vegetable Glycerin + whatever the hell the flavours are made of and suspended in.
whatever sugar in there is part of the flavouring + whatever weird and wonderful chemical reactions happen with various flavourings and the PG & VG & nicotine that are used in there.
And yes, it absolutely does caramelize and build up on the coils. Basically, whatever does not turn to vapor when you take a whiff, tends to either go back to the liquid or stick to the coil, which over time builds up and you can then either burn off the residue or toss the coil and get/make a new one together with the wick. if anyone cares, there's a ****ton of info out there about all this crap, as well as a ****ton of lies, bull****, wishful thinking etc.
No, we arent sure if they are safe. Its not a verified well published fact that they are generally safer than normal cigarettes (AFAIK!). Logic would presume that the lack of the whole "burnt carbonized leaves + additives being inhaled" means they are safer than normal cigs. I personally neither know nor care much. What i do know is A) they dont stink up the place/clothes for ages B) my significant other doesnt mind them at all C) THEY HAS SWEET TASTES! D) cheaper. by like a lot.