The impending ban on imitation tobacco products such as e-cigarettes, e-pipes and e-cigars was questioned by some MPs, even as they supported the changes made to the Tobacco (Control of Advertisements and Sale) Act.
They argued that these imitation tobacco products might be useful in helping smokers stub out.
Mr Louis Ng (Nee Soon GRC) noted that Britain, New Zealand and the United States have done extensive studies and endorsed policies that allow such products.
He wondered if Singapore "might be missing out on a chance to benefit" from a policy that allows the controlled use of these products to help smokers give up cigarettes.
Non-Constituency MP Leon Perera suggested letting smokers have "a controlled quantity of e-cigarettes'', but they must register with the Health Promotion Board for a smoking cessation programme.
"It is not easy for smokers to quit,'' he said. "Surely, the humane thing to do is to allow smokers - both those seeking to quit and reduce consumption - an avenue to use a less harmful product?"
Criminalising e-cigarette users, regardless of their age, sends the signal that imitation tobacco products are as harmful, if not more so, than regular cigarettes, he added.
Responding, Parliamentary Secretary for Health Amrin Amin said the number of studies showing imitation tobacco products are a gateway to regular cigarettes outnumbers studies that claim otherwise. These studies are also more authoritative.
He said: "We are aiming for a high and precautionary level of public health protection." He also said nicotine in imitation tobacco products produces toxic substances that "increase the risk of cancer of the throat, stomach and bladder".
Later in the sitting, Senior Minister of State for Health Chee Hong Tat asked Mr Perera if he was supportive of e-cigarettes because his business consultancy, Spire Group, had a client that supplies glue used for cigarette sticks.
Mr Perera said it was a small client from the past, adding that he strongly objected to any insinuation that he was motivated by financial or commercial gain.
Some MPs also asked why the minimum smoking age was being raised in phases to 21 instead of being done at one go.
Ms Joan Pereira (Tanjong Pagar GRC) was worried it would cause confusion and provide youth with a "so-called unique chance to be among the last batch of those who get to smoke legally below the age of 21".
Mr Amrin Amin said an immediate change to age 21 would affect about 12,000 young people aged between 19 and 21.
Smokers need some time to kick the habit, he pointed out, so the "phased implementation provides a realistic timeframe".
He also noted that "raising the minimum age alone will not eliminate smoking". Hence, the Health Ministry will "continue to send a strong message to young people to stay away from cigarettes".