Originally Posted by
torquemax777 
I just wondered how much I have cut back on nicotine only vaping half of 1.6ml of e juice?
Like others have said too, it's very very hard to compare. The people who are involved in advocacy for e-cigs are also very much against these comparisons, as it's mostly marketing hoopla. ("this cigalike will replace 2 packets of cigarettes"... no it won't)
You have cut back 100% on benzene, carbon monoxide, arsenic, and 4000 ish (depends on the source, 3500 to 4000, of which 600 to 800 are added by the manufacturers) other chemicals of which at least 30 known carcinogens. A wild guesstimate would be that (are you using 18mg juice?) you now use about 6 to 12 mg where you used to consume at least 25 to 50...
The focus on nicotine is a weird one, and also controversial, but again most people - even the most committed anti e-cig folks - will confirm that nicotine is not a carcinogen.
PG and VG are sugar alcohols and pretty harmless (toxicity is in the dose, like with everything), and considered as GRAS. They are sugar alcohols (so forget about lipid pneumonia and all that misinformation, you need to inhale a lipid for that), anti-bacterial, and used in thousands of products. Sure, not all of them inhaled, although PG is added to some asthma inhalers for its antibacterial properties. But inhaling too much can be an irritant to the throat (completely reversible by stopping vaping for a while, or by switching to a higher VG content e-liquid).
The risks as defined now are mostly in flavors oddly enough. Sure, they are food grade flavors, but designed to ingest, not inhale. There have been some chemicals already identified as potentially harmful (like diacetyl and other diketones), but a) those are in cigarettes as well in higher doses and b) the industry is starting to clean up its act too when it comes to those.
Anyway, I could write for days about this, but the simple truth is: not vaping is healthier than vaping. But compared to smoking combustible tobacco, vaping is probably 20 to 100 times less damaging from a toxicological point of view.
Many forums will not want it discussed because of the addiction part; they see it as a new way to get addicted. Some of these people are genuinely concerned, others are protecting vested interests.