The Mandate trade union wants health officials to reveal more details about the increase of coronavirus clusters in the workplace.
It is after the Acting Chief Medical Officer said there have been outbreaks in supermarkets and fast food outlets.
There are concerns that complacency could creep into the workplace as coronavirus restrictions ease.
The Acting Chief Medical Officer said they are seeing outbreaks in work settings like building sites, supermarkets and fast food outlets.
Dr Ronan Glynn says these places are the new frontline and is asking employers to ensure workers are protected.
Speaking last night, Dr Glynn said: "We are now seeing outbreaks of the virus in a range of work settings, including in construction, in fast food outlets and in supermarkets.
"We can’t underestimate how quickly clusters develop. We have come so far together, but we need to stay vigilant to prevent a resurgence across the whole country in the coming weeks.
“Many workplaces have introduced the new regimes and safety measures necessary to reopen their businesses.
“I would remind all employers that the workplace and most particularly, shops, services and supermarkets, are the new front line, we are asking you to do everything you can to put the safety of your staff and customers first.
“With the increase in outbreaks in our communities, I would urge everyone to wear face coverings in healthcare settings and when shopping, including in the supermarket and other indoor retail services.”
Gerry Light, from the Mandate Trade Union, says they want more information about where exactly he is talking about.
“We’ve been unhappy for a while now that in the categorisation of the different workgroups that retail workers haven’t been detailed in a manner that we would be satisfied with," he said.
“So obviously we need to get more details in respect of the extent of the increases and the nature and the type of retail employments that they’re happening in.”
For its part, Retail Ireland, which represents employers, says the number of Covid-19 cases linked to shops has been very limited over recent months and they will continue to follow best workplace practices.
Mandate is also appealing to customers to think about retail workers and their families and to wear a face mask.