On Thursday, as the news broke and the government faced off with the opposition over its decision to keep the school open, parent Alonso Chiok Diaz was picking up his eight-year-old daughter Cielo Chiok-Medrano from the Harrison School in Gungahlin.

She was playing with a friend in a garden bed that wasn't yet fenced off, he said. Later, his wife called to tell him a small amount of asbestos had been found in a number of other garden beds at the school.

All such sites, including the spot where Cielo was playing, have since been fenced off for testing.

"It's scary, I don't know if I should take [my daughter] to the doctor," Mr Chiok Diaz said.

"No one has told me anything, I've only seen things on social media."

An ACT education directorate spokeswoman said a licensed asbestos consultant found the cement sheet debris, containing non-friable asbestos - that is, unable to be pulverised, crumbled or reduced to power by hand - randomly scattered throughout some of the tested garden beds in a low concentration.

"The licensed asbestos assessor confirmed the material discovered in the school’s garden beds was non-friable asbestos, and exposure to airborne asbestos is unlikely unless the material is further broken," she said.

"To eliminate the chance of this material being disturbed, all school garden beds have been declared out-of-bounds and fenced off."

Once the source of the material was confirmed, a decision about testing other schools or sites would be made, she said.

A WorkSafe spokeswoman said the investigation into how and when the garden bed fill was placed at the school was ongoing, but the risk to health was considered low.

"It is understood the material is small fragments of non-friable asbestos," she said.

"Once full test results are received, licenced asbestos assessors and removalists will determine the approach to remediate the site."

While principal Jason Holmes has since committed to providing daily updates on the situation to parents, those who spoke to The Canberra Times said they had been largely left in the dark by government investigators as details remained unclear.

Students appeared to be receiving even less information and a number were scared to be at school, which is now encircled by fences, they said.

"It looks like a jail, we aren't being told anything," one parent said.

The asbestos was discovered at the school after a parent raised concerns last Monday, but Mr Holmes said the chance of finding the dangerous substance was initially thought to be minimal, given the relatively recent construction of the school in 2008.

As of Friday, when more garden beds were fenced off, representatives from parents' groups said the Harrison School appeared to be taking a cautious approach.

"Until we know what the material is, and tests are confirmed and we know where it came from, we can work out a plan for what to do next," Harrison School's Parents & Community Association president Jackie Floro said.

Shadow minister for education Elizabeth Lee called for the ACT government to provide an update to the community as soon as possible.

With Sally Pryor