Nurses have lodged a dispute against Queensland's health department over fears ill-fitting protective gear could see them infected with coronavirus.
The nurses' union is taking Queensland Health to the industrial relations commission demanding assurances that respiratory protection equipment is being properly fit tested and checked.
The commission is due to hear the matter at 2pm on Wednesday.
The union has particular concerns about what's being done to ensure the safe use of P2/N95 respirators, used by nurses and other staff who care for COVID-19 patients.
The Queensland Nurses and Midwives' Union says frontline staff must be given personal protective equipment that's been checked and fitted with a proper seal.
"But we have still don't have assurances that this is consistently being done across the state's public health system," union secretary Beth Mohle said on Wednesday.
"We're now extremely concerned that nurses and other health workers treating COVID-positive and, potentially positive patients, are not being properly fit tested for their PPE - and the consequences of this could be catastrophic."
The union wants reliable, up to date information about the fit testing of respirators from every hospital and health service in the state.
Concerns have been heightened by the recent transmission of COVID-19 to three nurses and a doctor at Brisbane's Princess Alexandra Hospital.
Those infections sparked a three-day lockdown across the greater Brisbane area.
Earlier on Wednesday, authorities revealed traces of coronavirus had been detected at the hospital's infectious diseases unit, despite a deep clean being carried out a week ago.
Ward 5D remains closed after it was shut late last month when it was found to be at the centre of two clusters that ultimately spread to 23 people.
Health Minister Yvette D'Ath is seeking more information on the situation at the hospital.
"It is not unusual for traces to be found that are not contagious," Premier Annastacia Palaszczuk said.
"My understanding is that it's not contagious after a period of time.
"We need to let the health experts look at the issue and report back about that."
