If Health Canada has its way, this year vaping will be dealt three knockout blows that will see, not just the end of the business as we know it, but an increase in smoking-related deaths nation-wide. Ottawa is recalibrating the delicate equilibrium between harm reduction and youth use of nicotine. It plans to introduce a mandatory limit on nicotine concentration in e-cigarettes and to ban most flavours. Maximum permissible content is currently at 66 milligrams per millilitre; the new limit will be 20. Eventually, we will see strike three: excise taxes.