SINGAPORE - About 40,000 migrant workers who stayed in dormitories have been cleared of Covid-19 infection and may return to work, pending approval from the authorities.

Of these, 12,000 are essential workers who had already been moved out of dorms into other short-term accommodations, said Manpower Minister Josephine Teo at a virtual press conference on Monday (June 1).

More than 20,000 workers have recovered from the coronavirus and been rehoused at various temporary sites.

A further 8,000 are dorm residents who have either tested negative for Covid-19 or tested positive but have since fully recovered, been discharged and are now living with their fellow workers.

She added that a first batch of 60 dormitories - including three purpose-built dorms as well as 57 factory converted dormitories and construction temporary quarters - will be given cleared status from Tuesday - the first day after the circuit breaker period ends.

"What does it mean to say a dorm has been cleared?" Mrs Teo said. "It means every block in a dorm has been cleared and every resident in those blocks has been cleared of Covid-19 infection."

The inter-agency task force handling the situation in the dormitories has improved medical support for migrant workers to enable them to return to work safely, she noted.

This includes a programme of systematic and regular testing, as well as enhanced health surveillance to enable early detection of any infection - and in the case of the cleared workers, re-infections.

One new measure rolled out by the task force is an access code feature on the SG Workpass app, which Mrs Teo said almost all migrant workers have downloaded.

This will give workers, their employers and dorm operators clarity about who can exit the dorms to work, she said.

Workers will need to have a "green status" on the app to indicate that their employer has been granted approval to resume operations, and that the dorm they stay in has also been cleared.

Asked how re-infection can be prevented, Mrs Teo said that greater discipline will have to be instilled in the workers' day-to-day living. "The simple idea is that you cannot go back to the practices of the past," she said.

Workers have to be split into cohorts who work and stay together, she said. Safe distancing measures must be implemented in the dorms, like erecting barriers between blocks so that residents of different blocks do not mix.

Rest days need to be staggered and workers should only use communal facilities like toilets that they are designated to, she added.

"But we still have to be mindful that in spite of all these measures, the risk of reinfections for the workers individually and the risk of clusters forming remains," she said.

"We cannot assume that with these measures, there will be no reinfections. The risk of infection remains there. What we therefore need to layer on is a rigorous system to test the workers, and that is what we are working on."

This article has been edited for clarity.