Colorado Gov. John Hickenlooper has signed an executive order intending to crack down on e-cigarette use by teenagers.

The Denver Post reports the Democratic governor’s order Friday directs regulators to increase checks of retailers to make sure they are not selling to underage customers.

The order also recommends for state legislators to raise the minimum age of purchase from 18 to 21 for tobacco and vaping products, and to consider banning the sale of flavored tobacco and e-cigarette items.

The governor has instructed the state health department to issue a health advisory on e-cigarettes and to investigate the relationship between vaping and other “risky behavior.”

The order also bans vaping in state buildings and on state grounds.

According to the state, about 27 percent of high school students use e-cigarettes.