Mandate Trade Union has written to all major retail employers and the Minister for Health calling for the provision of free antigen tests and high quality masks for workers in the retail and hospitality.
The union said that changes to government guidelines around close contacts and isolation periods have put more workers at risk of contracting the virus.
Jonathan Hogan, Mandate Assistant General Secretary, said that the government and employers have a dual responsibility to protect staff to the greatest extent possible.
"Many retail workers on the frontline have been utilising rapid antigen tests in a proactive manner in an effort to protect themselves, their families, their colleagues and customers from the virus.
"While some employers have taken positive steps and provided their employees with antigen test packs, not all have done so and many workers are left out of pocket for attempting to protect the community from transmission of this virus.
"This is inherently unfair," Mr Hogan said.
Most workers are being provided with medical grade masks, however Mr Hogan said there is mounting evidence that they are not adequate.
"The US Centre for Disease Control and Prevention does not consider medical masks respiratory protection. Therefore we believe all customer facing workers should be given the greatest protections possible such as FFP2/FFP3 or N95 masks and we're calling on employers and the government to ensure this is done immediately."