Your response was exactly what "attacking a strawman" is. I was talking about how I use American sourced propylene glycol versus Chinese PG as used in the samples where DEG was found. You responded to a statement I never made, that something is "100% natural". You are clearly an intellectually dishonest person so, sure, see yourself out of the conversation.
You can call me biased but you have failed to to make any sort of substantive argument on the science. I have critcisms of the safety on ecigs and some false claims people make too.
The real angle for safety you want to go at, if anything, is the addition of volatile diketones in creamy/buttery flavorings (diacetyl, acetoin, acetyl propionyl, etc.) Some of these small businesses selling liquid claim they use FDA-approved flavorings.
The FDA doesn't approve flavorings. It is sourced out to a group called FEMA (no, not that FEMA): http://www.femaflavor.org/gras
The FDA largely accepts the opinion of FEMA for what is GRAS (generally recognized as safe). Flavorings are only GRAS at varying levels for the intended usage (baking, alcoholic beverages etc., none of which is inhalation).
Diacetyl is not safe to inhale and has been known to cause bronchiolitis obliterans AKA "popcorn lung" both in workers at flavoring plants and even cases like a man who ate multiple bags of microwave popcorn per day.
I'm worried that these smaller eliquid makers haven't taken the warnings on this seriously enough and in a few years the first cases of this will appear. It can be a long process for popcorn lung to develop but the harm is irreversible. It is only this class of flavoring chemicals which raise concern, so I am sure to avoid them.