SafeWork SA has been warned of dangers created by overcrowding at Adelaide's Lyell McEwin Hospital (LMH).

The South Australian Salaried Medical Officers Association's (SASMOA) says it was forced to inform the regulator because staff and patients are at risk.

“We saw an over abundance of patients, a lack of medical staff, nursing staff, administrative staff to meet that demand,” SASMOA senior industrial officer Bernadette Mulholland has told the ABC.

“What's at risk is eventually someone will die because the staff can't get to all of these people who come through the door.

“Eventually we'll hit a crisis period, staff become distressed and the patients become distressed, families become distressed and it's just no longer acceptable.”

She alleged that on the day of the union’s visit, there were more than 80 patients waiting to be seen by emergency staff.

Additionally, she claimed that a 12-bay area where critically ill patients were cared for was holding 24 people.

“Throughout the day there had been barouches [hospital beds] with patients left in the corridor,” Ms Mullholland wrote.

SASMOA has called on SafeWork SA to investigate “the health, safety and welfare risk to doctors and patients who attend the LMH ED”.

But Health Minister Jack Snelling claims that the doctors’ union is putting up “roadblocks” to stop improvements of the hospital's busy emergency department.

“They have valid concerns about the busyness of the emergency department at Lyell McEwin Hospital absolutely, but what they don't have is a good track record of partnering with the Government to actually fix the problem,” Mr Snelling said.

“Lyell McEwin Hospital's emergency department is very busy because we have seen significant population growth,” Mr Snelling said.

“It really vindicates the Government's decision 10 years ago to begin turning what was a relatively small community hospital into a tertiary hospital to serve the growing population.”