A major British grocery chain has banned the high-caffeine drinks to minors under the age of 16.

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Caffeine is the most widely consumed recreational drug on the planet—in part because it is considered one of the safest (and some say can even help you live longer). The average adult drinks multiple cups of coffee per day without incident. And as recently as this past April, a systematic review of data on caffeine found that adults were likely safe to drink up to 400 milligrams of caffeine every day. But that’s adults, not minors, and in the United Kingdom, concerns over the effects of caffeine, sugar and other ingredients in energy drinks has led one major supermarket to ban the sale of these drinks to those who are under 16-years-old.

Starting on March 5, Waitrose—a somewhat upmarket British grocery chain a bit akin to Whole Foods—will become the first supermarket in the country to permanently require proof-of-age at all of its locations when purchasing drinks containing more than 150 milligrams of caffeine per liter. Nationwide, these drinks are already required to carry a health warning that reads: “High caffeine content. Not recommended for children or pregnant or breastfeeding women or persons sensitive to caffeine.” According to the Guardian, Morrisons—another U.K. grocer—trialed such a move at a handful of its stores back in 2015, but eventually abandoned the policy.

“As a responsible retailer, we want to sell these products in line with the labelling guidance,” said Simon Moore, Waitrose’s director of technical and corporate social responsibility. “These drinks carry advice stating that they are not recommended for children, so we’re choosing to proactively act on that guidance, particularly given the widespread concerns which have been raised about these drinks when consumed by under-16s.” Just last month, the teachers union NASUWT called for a ban like the one Waitrose just enacted. Other organizations, like the advocacy group Action on Sugar, have also supported such a ban.

Action on Sugar in particular points to the fact that energy drinks aren’t just packed with caffeine; they can also contain lots of sugar and other ingredients with purported energizing effects.

“Energy drinks are completely inappropriate for children to consume, form no part of a healthy balanced diet, and should be banned for under-16s across the board,” Katharine Jenner, campaign director at Action on Sugar, at Queen Mary University of London, was quoted as saying. It drives home a larger point that even if you question whether caffeine has a negative effect on children, energy drinks still aren’t necessarily entirely in the clear.