The Rest of the Story
If the Kentucky Center for Smoke-free Policy is correct, then the use of nicotine inhalers such as Pfizer's Nicotrol poses a grave danger to the public, as the nicotine exhaled by users may "react with a normal substance in the air to form cancer-causing agents that off-gas into the indoor air" and put people at risk of cancer.
After all, users of Nicotrol are also inhaling an aerosol mist that contains nicotine. If they, like vapers, are exhaling large amounts of nicotine that may react with ambient nitrous oxide to form carcinogens, then anyone who lives with a Nicotrol user or is exposed to Nicotrol use in a public place may be exposed to carcinogens.
Before all of you Nicotrol users out there start to panic, you ought to know the rest of the story. First of all, there is no credible evidence that even with thirdhand smoke, the deposition of nicotine on surfaces and its reaction with ambient nitrous oxide results in levels of, and exposure to carcinogens that are substantial enough to pose a risk to humans. So even if nicotine was present in appreciable amounts in "secondhand vapor," there is no documentation that it would pose any risk.
Second, and most importantly, there is no evidence, and little reason to believe, that there is any substantial release of nicotine into the air as a result of vaping. Unlike cigarette smoking, where nicotine is present in the sidestream smoke, there is no sidestream vapor produced by an electronic cigarette. Instead, the vapor is directly inhaled and so the only "secondhand" exposure is that resulting from the exhaled vapor from the user.
It is important to now recognize that nicotine is readily absorbed in the lungs. In fact, nearly 90% of inhaled nicotine is absorbed by the smoker and therefore, the levels of nicotine in exhaled smoke are quite low. The same phenomenon would also be true with vaping.
The vaper is going to absorb the overwhelming majority of nicotine so there will be very little nicotine in the exhaled vapor. This is why any carcinogenic risks resulting from exhaled nicotine are likely to be negligible. And this is in fact why the FDA
is not concerned about any potential carcinogenic risks resulting from the widespread use of Nicotrol inhalers.