Advertisers and retailers who sell tobacco products to under 18s face prison and fines of up to Dh1 million, UAE prosecutors said.
They reminded people of the tough penalties in a social media campaign.
According to UAE law, it is illegal to sell or promote cigarettes and tobacco products to teenagers.
Smoking in a vehicle when a child under 12 is present is also prohibited.
Advertisers who flout the rules could face fines of up to Dh1m, while those breaking the underage smoking rule risk a fine of between Dh500 and Dh10,000.
Yaqoob Al Hammadi, academic adviser at Sheikh Sultan bin Saqer School in Sharjah, said he had seen many pupils become addicted to vaping in recent years.
“It should be made more difficult for teenagers to get their hands on all tobacco products, especially vapes, because since these products have become popular, I caught many pupils them in their bags,” he told The National.
It is worrying because vapes are not as easy as cigarettes to detect, he said.
Tighter controls on shops selling vapes and other tobacco products to those under the age of 18 would help to reduce the number of pupils picking up the habit.
“It seems to be very easy for them to buy vapes if not from an actual shop, they get it online," Mr Al Hammadi said.
He urged parents to pay more attention to which products their children buy and use.
“Parents of the many pupils I caught smoking cigarettes, medwakh or vapes had no idea their children were smoking.”
As The National reported last week, a study found close to a quarter of university students smoke a vape on a regular basis - far higher than the number that smoke traditional cigarettes.