Employers have been warned they should limit gatherings of staff or meetings in a room to no more than two hours to minimise the risk of workers having to stay at home if one of them tests positive for the coronavirus.
It may mean colleagues who were in the same room as the person who tests positive will have to remain out of work for two weeks as a precaution.
The advice was clarified yesterday by Dr Ronan Glynn, deputy chief medical officer, who said this will become more relevant as more people return to work.
The rule applies to workers in a "closed space" like an office who are together for more than two hours if one of them is found to be diagnosed with the virus.
"Public health doctors will carry out a risk assessment and take issues into account such as size of the room, ventilation and distance from the confirmed case," he said.
Anyone who is deemed to be a "close contact" may have to stay at home for two weeks.
"It's not the same as saying every business cannot have people in the room for more than two hours but if there is a confirmed case as least some of them may be asked to stay at home."
He said it re-emphasised the need for employers to have as many workers as possible continuing to work from home as business resumes.
They should also limit the number of people attending meetings, he added.
Dr Glynn was speaking at the daily coronavirus briefing yesterday evening in the absence of chief medical officer Dr Tony Holohan, who was scheduled to take charge of the session as usual.
Asked about Dr Holohan's absence, he said he will be back working in the department today but did not elaborate any further.
There were 11 deaths from the virus reported yesterday, bringing the toll to 1,571.
A further 64 newly diagnosed cases of the virus were confirmed, bringing total infections to 24,315.
Figures show 87.1pc of people who caught the virus here have recovered - 19,224 in the community and 1,036 who were admitted to hospital.
But despite the downward trend, Dr Glynn said people were still falling ill and 16 patients were admitted to hospital with complications of the infection in the previous 24 hours.
Asked about plans by four in 10 pubs in Dublin to open as restaurants next month, he said it would have to be done in a safe manner.
Pubs serving alcohol cannot open next month and, according to the exit roadmap, they should not reopen until August.
He indicated that the scheduled roadmap is likely to be followed with no decisions made to fast forward any of the planned reopenings.
However, he did indicate that the National Public Health Emergency Team will discuss activities for children tomorrow, although schools will not reopen until September.
He did not elaborate on what areas of activities relating to children would be discussed, but it has been speculated it would revolve around summer camps, play and sport.
Asked about resumption of school classes before the end of this term, he said experts here were learning from other countries where schools have reopened.
He said 16 staff who worked in meat plants have been hospitalised so far with the virus and four infected members of the Roma community have died.
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