I agree with the British Royal College of Physicians findings that vaping is 95% safer than smoking. We know what happens long term with smokers who are susceptible to the chemicals in cigarette smoke. But then, there are smokers who live a long life and don't develop smoking related illnesses. Obviously, there's something in our DNA differences that governs that.
After smoking for 40 years, I was used to having something to do with my hands and I enjoyed the relaxing act of inhaling and blowing out smoke. If it hadn't been for ecigs I might have never quit, or at least I'd be as miserable as the time I quit cold turkey for two years.

That wasn't fun at all.
I don't think anyone can say it's totally safe, but it's a huge improvement over burning tobacco and inhaling it. Even the air we breathe isn't completely safe. It's full of foreign compounds introduced by industry and fossil fuel exhaust.
Royal College of Physicians Says Vaping Saves Lives