Teenagers in North Carolina who try to buy electronic cigarettes online are likely to succeed even though selling the devices to minors is illegal in the state, researchers reported on Monday. 

A 2013 North Carolina law required that online e-cigarette sellers verify customers' ages with a government database at the point of order. But more than 90 percent of vendors do not comply, researchers led by Rebecca Williams of the University of North Carolina at Chapel Hill found.

"It is likely easier for many teens to buy e-cigarettes online than in a corner store, where they might be faced with a request for ID," Williams said.

The situation is likely similar in other states, she added.

While 41 states ban e-cigarette sales to minors, "they tend to focus on face-to-face sales," imposing fewer or no restrictions for online sales, said Camille Gourdet, a health policy researcher at the University of Illinois at Chicago who was not involved in the study.

North Carolina is one of the few states that address remote sales, she said, and vendors shipping to minors there could be charged with a class 2 misdemeanor.

For the study, published online in JAMA Pediatrics, researchers supervised 11 teens ages 14 to 17 as they attempted to buy e-cigarettes online 98 times. They succeeded 75 times; 18 failures had to do with broken websites or payment processing.

Only five failures resulted from age verification measures such as requesting a social security number and date of birth, meaning 94 percent of the vendors failed to vet ages properly.

Other sites had some form of age verification, though they were ineffective, such as check boxes. None required drivers license numbers at the time of purchase.

"Without strictly enforced federal regulations, online e-cigarette vendors have little motivation to decrease profits by spending the time and money it takes to properly verify customers' age and reject underage buyers," Williams said via e-mail.

The packages were delivered by the U.S. Postal Service, United Parcel Service Inc, DHL Worldwide Express, or FedEx Corp, which do not ship traditional cigarettes to consumers under their own policies or federal regulation. None attempted to verify consumer age, and almost all left the packages at the door.

No federal law restricts e-cigarette shipping.