It may seem peculiar for a city that's home to an innovative manufacturer to ban retail sales of that company's product. But that's San Francisco.

It's likewise peculiar for a company that presents its product as a solution to the dangers of cigarette use to target the still-addictive creation to adolescents by coating it in whimsical flavors and colors, but that's Juul Labs, the most popular e-cigarette producer in the country.

So it is that the San Francisco Board of Supervisors — the equivalent of a city council and county board rolled into one, because the city and county there are — has voted to prohibit sales of e-cigarettes within the municipality's 47 square miles. The devices still will be available just down the peninsula or across the bay, and traditional cigarettes and marijuana products still will be legal in San Francisco. It's a bit of a go-figure situation, yes.

You probably know the basics — e-cigarettes are juicy with nicotine but lighter on some of the other toxins found in conventional cigarettes. This is said to make them safer, although no one really knows the long-term health effects of vaping or juuling (the jaunty terms for how an e-cigarette's effluvia are consumed).

The ban, enforcement of which would begin in seven months, is likely to be challenged. Juul is trying to collect enough signatures to put the matter to voters in a ballot initiative.

San Francisco's goal is to curb vaping by teenagers, a trend that has been compounding, and to prod the federal Food and Drug Administration to conduct a full-scale assessment of e-cigarettes.

The Star Tribune Editorial Board is sympathetic to the supervisors' motives — and has supported federal regulation of e-cigarettes — but the first-in-the-nation action does make matters murky. The problem is not so different from one we've seen in Minnesota, where several dozen localities have raised the age limit for tobacco purchases to 21. We support individual increases to the age limit but think it best for the state or even Congress to take it from here. It's ineffective to have a patchwork of laws addressing a universal threat.

But everything starts somewhere, and often on the coasts.