Let's 'translate' (though we shouldn't...) what we can get in as to vapor (the 2 to 3 ml. even though most of that is blown out again, but lets take that number anyway - spread out over a full day, in comparison to a kg of our flesh) to a kg of those rats. 2 ml is somewhere near 2 mg; 1000 mg is a gram; so that makes the minimum 7.7 gram (7700 mg) needed in that test a (roughly) factor 3800 times the amount we are getting in. While a factor 100 is usualy taken as 'safety-factor' to discern what will be called a 'safe' margin for us, as I understand it (mind you I'm not a scientist but that's what I am seeing when I read test-results and their translation). Which would then leave us still another 3700 factor as extra margin.
Or put another way: to compare, the rat should be getting not 7.7 gram per
kilo, but 0.002 gram/
kilo instead, to 'translate' to what we are getting correctly. Big difference...
Now of course it's each person's own call to decide whether something is acceptable to him/her or not. I know it is (more then) for me; but each must make their own decision of course. E-smoking does not come with guarantees... it's new, and each must decide for themselves what is or isn't acceptable.
Also, just as a side-note (and reason why the above 'sum' shouldn't really be made): I think it would be better to not mix different ways of getting things in. This was about vapor and not ingestion for instance - don't forget, what can be handled one way is not neccessarily without danger in another way. We don't eat what we put on our skin, we don't inhale what we eat, we don't eat what we inhale (at least... one being okay doesn't mean the other ways are just as okay). So better not compare two different ways to each other, just to be safe, would be my choice at least.
As to lactid acid - no-one is saying that it is 'good' to have it in your body: it isn't and too much can cause harm (too is néver good, of anything...). But our body can handle it, get rid of it, because it does occur in overdoing sports for instance also - and we do get over that, be it with a bit of pain sometimes (and of course: this is about a moderate quantity - anything can kill you or cause harm in too big quantity - try gulping down a few gallons of clear water within a short time: lethal water-poisoning can occur... and that's just plain clear 'healthy' water... again, 'too' is never good).
