Asbestos-tainted mulch has forced a primary school to close for several weeks as "disappointed" authorities wonder why recycled material was ever laid where children play.
The hazardous material was identified last week in recycled mulch put down at a playground at Liverpool West Public School, a primary school in Sydney's southwest.
It has been linked to the same supplier common to 21 other sites across Sydney found with asbestos-tainted mulch.
While usually laid on topsoil, the mulch at the school was far deeper than usual and required a large operation to replace, Education Minister Prue Car said.
"There is so mulch that needs to be removed that we need a couple of weeks to do that properly," she told reporters on Wednesday.
"It is an extremely disappointing situation."
The 700 students have been taking lessons from home this week and will begin face-to-face learning at the nearby Gulyangarri Public School in the coming week.
The playground was opened on December 8 after a recent school upgrade.
But recycled mulch should never have been used at the site under education department rules for upgrades or new builds, Ms Car said.
"It's part of the reason why this is so upsetting, quite frankly, for parents and for us as government," she said.
"We have to stand up the whole school at another school because recycled mulch was used when it shouldn't have been."
While not immediately dangerous like fibrous asbestos due to being sealed with concrete or resin, bonded asbestos can become powered once it decays.
Greenlife Resource Recovery, the supplier linked to 22 contaminated sites including the Rozelle Parklands in Sydney's inner west, denies its mulch was tainted when supplied.
The company on Tuesday said its testing showed mulch stockpiled at its facility was free of asbestos contamination.
It is challenging an Environment Protection Authority order banning it from further supplying its mulch in NSW.
