They fear children may have been exposed to asbestos for months or even years at a Queensland school.

A teacher reported seeing dust falling from a ceiling at Rochedale State School, south of Brisbane, on March 8, leading to the evacuation of two classroom blocks housing year one, two and three students.

The Education Department took 89 samples and four days later parents received confirmation 14 had tested positive for the banned building material.

Children were moved into libraries or unaffected classrooms while further testing and reports were done.

But parents allege students are returning to asbestos-impacted classrooms with only sealant applied to the ceilings.

The Education Department says asbestos removal from the classrooms has been scheduled for the Christmas holidays.

Concerned parents expressed their fears for their children outside Queensland parliament on Tuesday, with some mothers breaking down as they spoke to reporters.

"(The school) told us they can't give us 100 per cent reassurance that exposure won't occur from the same source," parent Adam Littlefield said.

Some mothers, who did not wish to be identified, sobbed while sharing concerns their children may have long-term health impacts from exposure to asbestos which can cause lethal disease.

Mr Littlefield said he was afraid all three of his children who go to the school have been impacted.

"I can't put my son back in that classroom because the risk is too high," he said.

Parents have called for demountable classrooms to be provided while the asbestos is removed but claim their request is being ignored.

"It's very frustrating. We are shocked at the way this has been handled," Mr Littlefield said.

The Education Department said it was confident every measure had been taken to ensure the classrooms were safe to reoccupy.

"Ongoing air monitoring in these classrooms and physical inspections of the ceilings will continue until the scheduled removal occurs in the Christmas holiday period in order to provide an additional level of assurance to the school community," it said in a statement.

Premier Steven Miles was pressed on the issue during state parliament's question time on Tuesday.

Mr Miles said the health and wellbeing of the Rochedale students was a priority and testing was being done.

"Advice from experts is that all the classrooms are safe for staff and students to return," he said in response to a question from LNP member Christian Rowan.

"I'm advised there have been three separate clearance certificates issued by independent occupational hygienists with the most recent certificate issued last week."

Dr Rowan said the government could not give complete certainty to parents that there were no ongoing risks and exposure.

"I'm calling upon the government to be open and transparent in relation to this incident, to provide assurances to these parents and to communicate and work with the parent cohort to ensure that their children are safe," he said.

Australian Associated Press