Teenagers are easily able to purchase e-cigarettes online, according to a recent study.

Researchers at University of North Carolina at Chapel Hill found that minors are easily able to buy electronic cigarettes online because both Internet vendors and shipping companies failed to verifying ages in a study that assessed compliance with North Carolina's 2013 e-cigarette age-verification law.

While analysts have forecasted e-cigarette sales could hit $10 billion by 2017, the Centers for Disease Control and Prevention has reported increasing e-cigarette use by teenagers. While 41 states currently ban e-cigarette sales to minors, compliance with these state laws has not been assessed.

Researcher Rebecca S. Williams and her colleagues enlisted 11 nonsmoking minors between the ages of 14 and 17 to make supervised e-cigarette purchases from 98 Internet e-cigarette vendors.

The minors successfully placed 75 orders. Of 23 unsuccessful orders, only five were rejected for age verification, which means 93.7 percent of e-cigarette vendors failed to properly verify their customers' ages, according to the study results.

The delivered packages of e-cigarettes also came from shipping companies that, according to company policy or federal regulation, do not ship cigarettes to consumers. None of the vendors complied with North Carolina's e-cigarette age-verification law.

"In the absence of federal regulation, youth e-cigarette use has increased and e-cigarette sellers online operate in a regulatory vacuum, using few, if any, efforts to prevent sales to minors. Even in the face of state laws like North Carolina's requiring age verification, most vendors continue to fail to even attempt to verify age in accordance with the law, underscoring the need for careful enforcement," the study concludes.

The findings are detailed in the JAMA Pediatrics.