isn't
vaping 3ml comparable to smoking about one pack of cigs?
I don't think you can really make such a general comparison like that. Kind of like comparing apples to oranges.
Although some cigarettes are longer (100s) and some are shorter (72s), and some are stronger (full flavor) and some are milder (ultra lights, etc)....a pack a day is a pack a day, pretty standard.
It isn't that way with vaporizing, at least I don't believe it is. For example, cartos absorb quite a bit of e-liquid, much of which you don't actually vape off.
Different batteries/top parts produce varying amounts of vapor, and some use u e-liquid more efficiently than others.
So it is really hard to say how much e-liquid equals a pack of cigarettes.
Not to mention, with vaping, you don't absorb even HALF the amount of nicotine as you would from smoking a cigarette. Smoking cigarettes is by far a more efficient delivery mechanism (just terribly, terribly unhealthy).
If I tried to smoke all day, everyday, I would be sicker than I've ever been in my life.
Yet I can vape all day everyday, with no nicotine overload, and no ill-effects whatsoever.
So I don't think you can really compare the 2. They are just two entirely different delivery mechanisms of nicotine.