They also emit nicotine vapour — as do regular cigarettes. The difference is e-cigarettes emit no products of combustion (as there is no combustion involved; while smoking tobacco emits up to 4,000 toxins.
E-cigarettes ingredients include: Propylene Glycol and/or Glycerin, and flavor. All of those ingredients are also vapourized (not burned) — and the FDA has rated them as generally safe for use in food, cosmetics and medicines.
This is just another instance of propaganda, in the service of the totalitarian nanny-staters’ agenda.