Free face masks should be provided on Adelaide public transport to promote better compliance with COVID-19 rules and reduce community infection rates, the South Australian opposition says.

While masks remain mandatory on public buses, trains and trams, as well as in taxis and ride-share transport, the level of use has dropped in recent months.

Opposition health spokeswoman Ashton Hurn said the proposal for free masks had the support of health officials and should be adopted as a commonsense move by the government.

"As our hospitals endure extreme pressure during this third wave, providing free masks to support compliance on public transport is one action which could help ease the pressure on our health system," she said.

"This initiative aims to keep passengers protected on our trains, trams and buses and would mean South Australians are more likely to get on board with wearing masks and are more likely to continue patronising public transport."

The idea is expected to be a topic of discussion at Tuesday's meeting of the state's Emergency Management Council, which sets COVID-19 rules.

Free masks are currently provided in schools and in other high-risk facilities including hospitals and aged care centres.

South Australia's COVID-19 daily infection rate has fallen in recent days with the state reporting 2389 new cases on Monday, down from more than 5000 less than two weeks ago.

But hospital admissions remain high with 350 people in hospital with the virus.