Wearing a mask is not the most important thing to do to keep the coronavirus at bay, said Associate Professor Kenneth Mak, the director of medical services.
He was responding to questions on the advice circulated by four doctors that everyone should wear a mask when leaving home, regularly wash hands and reduce unnecessary mingling with others - challenging official advice which is to wear masks only if sick.
The doctors argued: "If one faces a person and both parties are masked, it is considerably safer, constituting a two-barrier protection."
Prof Mak noted there has been a lot of well-intentioned advice on social media, including from doctors. He said while some advice is very relevant, such as reminders to wash one's hands, people must remember the virus is spread via droplets with no evidence that it is airborne.
"Be aware of things you commonly touch. The thing most commonly touched is your phone, so wearing a mask is not the most important thing," he added.
Government leaders have said that only those who are unwell need to wear a mask, while those who are well need not do so. As the virus is spread by droplets, keeping hands clean, and away from the face, are more important ways to avoid catching the bug.
One of the four doctors, Dr Colleen Thomas, an internal medicine specialist in private practice, told The Straits Times they felt obliged to send out the warning as "the burden of not doing so is too great to bear".
Their letter shared on chat groups said: "The infected are not always traceable and containable within hospital isolation rooms. As this virus is said to be milder, infected people with no symptoms could transmit the virus to others silently."
Dr Thomas said: "As a doctor, how can I not speak out when I know that there is danger to people?"