Saturday Apr 27, 2019 at 2:00 AM "The effect of regularly inhaling vaporized glycerin and propylene glycol is not yet known." Q: My grandson is always carrying around a little device that he smokes like a cigarette. It puffs smoke just like one, too. I'm a former smoker, and my lungs aren't in great shape, so I'm worried. What is he using? Is it safe? A: Your grandson is vaping, which means he's inhaling an aerosol produced by the device you've seen him use. It's that aerosol, or vapor, that gives the practice its name. As for the specific type of device he's using, it's difficult to say without a clearer description. It's definitely not an e-cigarette; those look just like tobacco cigarette... [Read more]