California congressman vapes during Congressional hearing

[valerief]

3. Breathe in that nicotine and propylene glycol.

“It is a common misunderstanding that the exhaled vapor is ‘just water vapor,’ ” Tobias wrote me in an e-mail. A recent study he conducted found that nicotine and propylene glycol — a compound used in fog machines — can be found in e-cigarette exhalations. He did not find formaldehyde, which is common in real cigarettes.

But Tobias pointed out that some people are sensitive to propylene glycol.

So, e-cigs are better than real cigs, but possibly not as good as no cigs at all. Or, as a study by the German Cancer Research Center concluded: “Adverse health effects for third parties exposed cannot be excluded because the use of electronic cigarettes leads to emission of fine and ultrafine inhalable liquid particles, nicotine and cancer-causing substances into indoor air.”

https://www.washingtonpost.com/local/when-e-smokers-breathe-out-what-do-we-breathe-in/2013/05/28/ccce833e-c79c-11e2-9245-773c0123c027_story.html

You may already recognize this chemical for its more everyday use — as the key component in newer automotive antifreeze.
However, propylene glycol is considerably safer (less toxic) than its far more dangerous cousin — ethylene glycol.
Yet because of its proven ability to cause a serious type of blood disease in some animals — Heinz body anemia — propylene glycol has been banned by the FDA for use in cat food.
But unfortunately, it can still be used to make dog food.

http://www.dogfoodadvisor.com/red-flag-ingredients/propylene-glycol-dog-food-aid-or-automotive-anti-freeze/