The emergence of new consumer tobacco and nicotine products, notably electronic cigarettes and heated tobacco products, has produced controversy and confusion. This is partly because the two products are often conflated, not least by Philip Morris International, the world’s largest tobacco company. With global sales of cigarettes inexorably declining, the company’s future now depends on IQOS, its flagship heated tobacco product.

Yet e-cigarettes and heated tobacco products are quite different. E-cigarettes contain no tobacco but heat nicotine-containing liquids to produce an inhalable aerosol. [...]