I hear you mostlyclassics, it seems like it should be safer but if the film builds up there what is it doing in my lungs, or worse, someone else's? Please understand I am excited about vaping, I haven't had an analog in 7 months an I can breathe much better than in many years. That said I do not want to live with blinders on and in denial.
It's probably not doing anything, but long-term tests haven't been done, since vaping has only been around since 2006, when it was invented in China.
Let's review what's in our e-liquids:
With regard to PG, if you were born in a hospital, the first breaths you drew on this earth were well laced with PG -- it's been in use in hospital ventilating systems for many decades. PG is a germicide. Because of the PG scum problem, it's mostly been replaced with micropore filters. Also, many surgeons and OR nurses have spent 12 hours per day, five or six days per week in operating theaters for their whole careers, and operating theaters used to get really heavy doses of PG via the ventilation systems. And an awful lot of stuff we breathe, put in our mouths or eat are well laced with PG. The FDA has called it "generally recognized as safe."
With regard to VG, you find it in an awful lot of foods, both natural and processed. For instance, nearly all wines have an appreciable amount of natural VG. All told, you've probably ingested gallons of the stuff over your lifetime. The FDA has also called VG "generally recognized as safe."
Nicotine, well you'll have to draw your own conclusions, but from what I've read, it's not a carcinogen, just a mild stimulant which has other beneficial properties for certain people. It's probably not good for you if you have an advanced case of congestive heart failure or blood pressure high enough to pop your eyeballs out of their sockets, but otherwise it's a "so what?" on the order of caffeine.
Flavorings are the only real wild card: there's just not enough experience with inhaling these over a long period of time. But they're all safe to eat.
The heat to which we subject e-liquids is not enough to cause any of these ingredients to form new, noxious compounds.
And, remember, your lungs are
not garbage cans! Something you inhale just doesn't sit there until the day you assume room temperature. Since you've quit cigarettes, all the little ciliae in your lungs and bronchial passages have become unparalyzed, so they constantly shove anything your lung tissue doesn't like up your windpipe to the point where you either cough up the offending goop or swallow it.
