Three Tasmanian nurses have been assaulted in one night in the overcrowded emergency department of Launceston General Hospital (LGH).

The state secretary of Australian Nursing and Midwifery Federation (ANMF) Emily Shepherd said there were nine 'code black' calls on Wednesday night over threats of violence or aggression.

"Unfortunately, through those incidents three staff have been assaulted," she said.

Ms Shepherd said one nurse was punched to the face and suffered "significant bruising", while another two nurses were bitten on their bodies and required stitches.

"Our members should be assured of safety at any time they're at work," Ms Shepherd said.

"Any assaults on our members or any nursing or midwifery staff in the LGH should be taken incredibly seriously."

The union said two patients were involved in the assaults.

The ANMF believes Health Minister Michael Ferguson and the Tasmanian Health Service Executive (THS) need to look at the nurses' injuries in the context of the overcrowding issues.

"To date, the Minister has done absolutely nothing to address members' concerns," Ms Shepherd said.

"And now, not only are our members dealing with increased challenges to accessing patient beds, but they're also facing challenges in regard to their own personal safety."

Patients ramped

The union said on Thursday morning there were 44 patients in the ED including 19 awaiting inpatient admission, while several more were ramped on trolleys.

"So they're actually admitted patients waiting to be moved out into a bed on a ward or unit within the rest of the hospital," Ms Shepherd said.

"Staffing levels need to be reviewed, particularly given that there isn't any increase proposed for inpatient capacity at the LGH."

Nurses say patients are being admitted to the LGH but left waiting in emergency for a bed. ( ABC News: Damian Mcintyre )

The union has been holding vigils outside the LGH, aimed at urging the THS executive and the Minister to implement its "proposed strategies to ensure patient safety".

The ANMF will be meeting in coming days to discuss whether it undertakes more industrial action.

"We'll be ramping that up in the next week or two," Ms Shepherd said.

Emergency medicine training accreditation was stripped off the LGH in March following the departure of all but two ED doctors.

The Health Department said in a statement it would review the incidents.

"The Tasmanian Health Service has a zero tolerance regarding violence toward staff," department secretary Michael Pervan said.

"While hospital emergency departments can be challenging places, it is never acceptable for staff to be attacked verbally or physically."

The department said all three staff had returned to work with the appropriate support.

The state's Acting Health Minister Elise Archer echoed the THS comments.

"Any threat or injury to staff is completely unacceptable and will not be tolerated," Ms Archer said.

"We thank our hardworking staff for the incredible work they do, including their unwavering professionalism in providing care for their patients."