THE interests of cigarette-makers and regulators rarely align. To date, most rules have been bad news for Big Tobacco. Change came on May 5th, when America’s Food and Drug Administration (FDA) announced new requirements for electronic cigarettes.

The vapour industry is small—less than 0.1% of the tobacco market—but expanding fast. Global sales grew 11 times over in the five years to 2014, according to Euromonitor, a data firm. In America sales soared even more rapidly. To some, that raises an exciting prospect. E-cigarettes might help smokers inhale nicotine without the deadly stuff that comes from burning tobacco. On April 28th Britain’s Royal College of Physicians argued that e-cigarettes could help prevent death and disease.

Yet e-cigarettes are not totally harmless. Nicotine seems to meddle with the development of adolescent brains, for example. Some vapour devices deliver dangerous chemicals, including formaldehyde. The evidence for e-cigarettes’ broad effects is still slight. Smokers may give up traditional cigarettes for electronic ones, but teenagers may do the opposite.

This month regulations in America and Europe were settled, after years of debate. To be effective, the rules should serve three goals: promote a basic standard of quality, nudge tobacco-smokers to try the electronic kind and discourage non-smokers, particularly children, from taking up e-cigarettes. The new rules, however, do something rather different.

On May 4th the European Court of Justice upheld a broad set of tobacco regulations. E-cigarette-makers must, among other things, notify regulators before they introduce a new product; cap nicotine levels; and warn users of nicotine addiction. John Britton of the Royal College of Physicians supports quality control, but says limiting nicotine may make e-cigarettes less appealing to tobacco-smokers.