NSW classrooms are still being assessed for ventilation, with the government yet to order any air filters, as students prepare to return to school from next month.
An audit of classrooms in the state's more than 2200 public schools started two weeks ago, education officials told a parliamentary inquiry into the government's COVID-19 response on Thursday.
Windows and fans have been tested in about half the state's schools, and it's planned to finish the rest before the end of next week.
Work has begun to fix windows that don't open fully or fans that don't work.
Of 9000 fans so far inspected, some 1100 were not working.
A staggered return to face-to-face learning commences on October 25, with further year groups to join in early November.
The NSW strategy to protect kids when they return to school involves masks, vaccinating teachers and ventilation, said Department of Education secretary Georgina Harrison.
The health advice is that fresh air is the best form of ventilation, Ms Harrison said.
The "primary source" of ventilation will be to allow fresh air into classrooms by opening windows and doors, she told the inquiry.
The government has not yet put in an order for air filters, another ventilation measure.
The Victorian government on Wednesday announced a $190 million package to fund 51,000 air purification devices for schools.
Ms Harrison said her department's focus was on safety rather than looking at the amount they were spending.
Though the government is in talks with potential suppliers of air filters in Australia and internationally, it is too early to put in an order, said the CEO of School Infrastructure NSW, Anthony Manning.
The department doesn't yet know what specifications of air filters it might need because it hasn't completed the audit, he said.
"If that audit shows we need additional support for ventilation in our classrooms then we will be looking into providing it, of course we will," said Ms Harrison.
Greens MP David Shoebridge suggested the department had "dropped the ball".
"Victoria is so far ahead," he said. "They've sourced 50,000, even though we're further down the curve (NSW) has not ordered a single one."
Politicians pushed the education bureaucrats to explain what they would do about classrooms where windows did not open further than 10 per cent because of the risk of falling, or on days when the weather or bushfires meant windows could not be open.
Ms Harrison said ventilation was only one part of the response, and masks and vaccinations were important too.
If bushfire smoke made it unsafe to be in a classroom, a school might have to temporarily return to learning from home, she said.
But after months without face-to-face classes for students, avoiding a return to remote learning should be a greater priority for the government.
"We don't want NSW students going back to remote learning because the NSW government wasn't quick enough to make classrooms safe," she said.
Meanwhile, Ms Harrison also the department was looking at the ability to redeploy teachers who refused to be vaccinated away from classrooms.
Teachers must have received two doses of the COVID-19 vaccine by November 8.
"For those who are unwilling to be vaccinated, we will need to look at our ability to continue to support their employment in a school-based setting," she said.
A department survey on September 17 found 79 per cent of teachers who responded - up to 50,000 people - had received at least one dose, with 56 per cent double-vaccinated.
Australian Associated Press