E-cigarettes are hot on the black market, given the rising number of cases the authorities have investigated in recent years.
From April 2014 to March this year, the Health Sciences Authority (HSA) probed about 15,000 vaporiser cases, including cases of people trying to sell them online or smuggle them here for their own use. Vaporisers include e-cigarettes and e-cigars.
This is almost 70 per cent more than theapproximately 9,000 cases probed in the preceding three years. Experts say this is a worrying sign of the growing popularity of e-cigarettes, despite laws prohibiting their sale and import.
Mr Lim Shen Yong, senior social worker at AMKFSC Community Services, said young people believe that e-cigarettes are less harmful than traditional cigarettes, and see it as a way to quit smoking or as a "healthier" option.
He added that "the easy access to e-cigarettes online" may have also added to their popularity.
It is already illegal to import, distribute or sell e-cigarettes, which are battery-powered devices that heat a liquid containing nicotine, producing a vapour that is inhaled.
Those convicted can be fined up to $10,000 or jailed for up to six months, or both, for the first offence, with harsher penalties for repeat offenders.
But it will soon be against the law to use them. Earlier this month, a Bill was introduced in Parliament to make it illegal for people to buy, use or possess imitation tobacco products such as e-cigarettes.
Those caught could be fined up to $2,000. This is one of the proposed changes to the Tobacco (Control of Advertisements and Sale) Act, which also include raising the minimum smoking age from 18 to 21.
An HSA spokesman said the move to ban the use of e-cigarettes "will further protect Singaporeans from the harms of using such products and prevent its use from being entrenched" here.
To many smokers, vaping seems like a cooler alternative. Many buy e-cigarettes online or in Malaysia.
A 20-year-old student who used to vape said: "Many people vape as they feel it's less harmful than cigarettes and it's more fun. It produces a huge cloud of smoke, which you can try to make shapes with. And it comes in all sorts of flavours, from bandung to green apple."
A 27-year-old musician said he started vaping a few years ago in a bid to stop smoking. His parents, who disapprove of smoking, remain unaware of his vaping habit, as e-cigarettes leave no smell.
The HSA has said there is no conclusive scientific evidence that vaporisers can help smokers quit.
Youth workers say the move to make the use of e-cigarettes an offence will hopefully deter people from picking it up for the first time.
Ms Lena Teo, psychotherapist at the Children-At-Risk Empowerment Association (Care Singapore), said: "The ban on e-cigarettes will deter those who have not tried smoking or vaping, but those who really want it will still find ways to get it. So it's also important to educate youth about its harm."