The Ambulance Employees Association has launched industrial action it says will cost the South Australian Government more than $1 million per week.

The Association says it is disgusted by the practice of ramping at Flinders Medical Centre in Adelaide, where patients are left in ambulances outside the Emergency Department or on stretchers in hospital corridors.

Paramedics have decided to not fill out patient information on case cards, which means patients will not be charged.

Union official Phil Palmer says paramedics are being put under too much pressure and lives are being put at risk when the facilities are full.

Mr Palmer says the practice has been happening for eight months and, despite talks with management, it happened again on Wednesday night.

"We had a critical patient who was a suspected heart attack on a stretcher for an hour-and-a-half inside Flinders waiting for medical attention," he said.

SA Health Minister John Hill says industrial action will not help.

"Not charging patients might make them feel good but it doesn't actually help the problem. We're trying to genuinely fix the problem," he said.