SINGAPORE - Those who may have been exposed to the Covid-19 virus can collect their self-test kits at 100 vending machines across 56 locations in Singapore from Saturday (Sept 18).

The antigen rapid test (ART) kits will be available for collection round the clock from machines placed in various housing estates, including Choa Chu Kang, Toa Payoh, Woodlands and Pasir Ris, said the Ministry of Health (MOH) on Friday.

The full list of collection points and the steps needed to get the test kits are available at this website.

From Saturday, people who receive a health risk warning or a health risk alert via SMS will also be given instructions by the MOH on a testing regime that they must follow.

A health risk warning is issued to those who, based on SafeEntry data, have been in close proximity with a Covid-19 case for an extended period, or are identified as a close contact of a case.

A health risk alert is sent to people whose SafeEntry records from the past 14 days overlap with those of a Covid-19 case. They are considered to be at a lower risk of infection compared with those issued with a health risk warning.

They may scan their NRIC or FIN to collect a pack containing three ART kits at the vending machines, and use them for self-testing to fulfil the requirement for a health risk warning.

Those who receive a health risk warning SMS notification must get a polymerase chain reaction (PCR) test at a Swab and Send Home (Sash) clinic or private practitioner, and self-isolate until they receive a negative result from their first PCR test.

Private practitioners that offer the PCR tests are Fullerton Health Testing Centre, Raffles Hospital or Kingsway Medical Clinic, said MOH. Appointments can be made at this website.

People issued with health risk warnings will also be required to perform self-administered ART tests on the third, fifth and seventh day from the day of last exposure to the Covid-19 case whom they were close contacts with.

They must also do another PCR test on or after the eighth day at a Sash clinic or private practitioner, said MOH.

"If all these are complied with, their HRW (health risk warning) period will end on the 10th day of exposure. All swab costs will be borne by the Government," said MOH.

The ministry said that those who receive a health risk alert SMS notification from Saturday should perform a self-administered ART on the first, third and fifth day from the day of last exposure.

They should also monitor their health until the 10th day of exposure.

"We urge all on HRA (health risk alert) to exercise social responsibility and limit their interactions with other persons during that period," added MOH.

ART kits have been distributed to residential households since Aug 28.

About 90 per cent of households will have received their self-test kits by next Monday, said Health Minister Ong Ye Kung in a virtual press conference by the multi-ministry task force on Covid-19 on Friday.

Schools and companies have also been given the kits, he noted.

"I encourage everyone to do the self-tests... I think using them will be a new habit in this Covid-19 new normal," he said.

The ARTs are not as accurate as PCR tests, but they can help to pick up cases quickly and prevent onward transmission of the virus, he added.