E-cigarette advertisements can be easily accessed by teenagers, even though U.S. rules call for tobacco websites to check that the users are legally above the age limit.

Following a 1998 legal settlement to the letter would make cigarette websites factor "age-verification gates", which need users to verify that they are 21 years old or above. 

However, researchers looked at websites for the 19 brands marketed by 12 leading e-cigarette companies. They discovered that just one of them called for detailed registration, said a report published in JAMA Pediatrics.

"Strong age-verification gates on e-cigarette websites would make it harder for the young teenager who has yet to vape to impulsively view e-cigarette websites," said lead study author Samir Soneji of the Dartmouth Institute for Health Policy and Clinical Evaluation and Geisel School of Medicine.

The "gates" can limit exposure to the e-cigarettes and even to the number of flavors put up on the sites to lure the users, Soneji added.

E-cigarettes are being developed by all the bigger corporates, such as Altria Group and Reynolds American. These are battery-powered and have attractive glowing tips, as well as heating elements that transform liquid nicotine, along with flavors, into a vapor cloud that can be inhaled.

The laxity in regulating access to e-cigarette sites is probably because vaping is found to be less risky. The simple composition of the vapor, compared to conventional cigarette smoke, is believed to have made it safer. 

Still, there should be strict limitations, the new study said. "Regardless of government regulation, tobacco companies ought to consistently apply their principles of corporate social responsibility across all products, not just cigarettes," the report concluded.

As the Food and Drug Administration has not been given complete regulatory authority over e-cigarettes, it cannot force the companies to put heavy age gates on their websites. However, critics insist that tobacco producers who are also selling e-cigarette products should not follow double standards while marketing both.

The study found that the age-verification gates tended to vary in strictness across brands. While two websites lacked gates, five sites featured warnings, 10 asked for clicks or checks that would give indications that users were above the age limit, one site made it mandatory to put in a birth date entry, and another called for detailed registration. 

Yet, the study does not validate that checking out websites makes teens vape, nor does it examine how adolescents react to the diverse kinds of marketing. However, last April, the U.S. Centers for Disease Control and Prevention (CDC) reported that teenagers who have tried to smoke electronic cigarettes might be twice as likely to transfer to conventional cigarettes compared to their peers who have not tried them. 

Hence, it is important to limit access to the products, say critics. Some viewpoints on how to prevent the use of teen purchases might be of more help, said Dr. Riccardo Polosa, who is undertaking tobacco research at the University of Catania, Italy, but is not part of the current study. It would be more helpful to pay attention to blocking teen purchases rather than limiting their online viewership. Hence, if the teenagers are asked to pay through credit cards, they might get automatically blocked out, if their ages do not exceed the limit to qualify for credit.

"There is a danger of trying too hard to hide adult society from adolescents - they may be attracted by 'forbidden fruit,'" Polosa added. "Telling a teenager they are too young to have something may simply increase its appeal or make it look more cool."