More than 20 primary schools and pre-schools have been closed after traces of asbestos were found in brightly coloured sand designed for children’s play and craft activities.

Supplier Educational Colours issued a recall notice on Wednesday for the sand products, which are imported from China and sold by retailers including Officeworks, Educating Kids, Modern Teaching Aids and Zart Art.

The Australian Competition & Consumer Commission said there was concern they may contain tremolite asbestos – which it described as “a naturally occurring asbestos” – after it was detected in some samples during laboratory testing.

“We have engaged with Officeworks, who is a major supplier of these products, and they advised that the products have been removed from sale,” ACCC deputy chair Catriona Lowe said.

“We expect they will take all the necessary steps to alert their customers.”

The products are labelled as Kadink Sand (1.3kg), Educational Colours – Rainbow Sand (1.3kg) and Creatistics – Coloured Sand (1kg). They were sold in Australia between 2020 and 2025.

WorkSafe ACT issued its own contamination notice on Thursday, saying laboratory testing had confirmed that Kadink Decorative Sand contained traces of a different type of asbestos called chrysotile.

On Friday, the ACT Government said the recall had prompted the closure of a number of public schools where the sand was used for sensory play, arts and crafts.

“While WorkSafe ACT has identified the risk of exposure to traces of chrysotile is low, the safety of our schools is our highest priority,” it said in a statement.

The Government said the closures would enable testing and “remediation” to occur as soon as possible.

It described the situation as evolving, and updated the list of closed schools on early Friday afternoon to include 16 primary schools and six pre-schools, with a further eight pre-schools partially closed.

Health risks to children are said to be low after initial air tests at eight ACT schools came back negative for asbestos, but results of other forms of testing are not yet known.

At least one school in Brisbane, Mancel College, was also closed on Friday.

“We have some of the product on site at Mancel College and it has been used in some of the Junior School and we have now found some in the Senior School,” it said in a social media post.

“While the advice is low risk and there are only minor traces, we are acting with an abundance of caution.”

A safety alert has been issued to all NSW public schools to remove recalled sand products.

A Victorian Department of Education spokesperson said it received advice the risk to health was low and had no indication of a need to close schools or early childhood services.

ACT authorities want all schools to re-open on Monday and parents will be notified of a decision on Sunday afternoon or evening, ACT Education Minister Yvette Berry said.

“Our first priority is the safety of our schools and students, and it is a workplace as well, so we need to make sure that all school staff are safe and protected,” she told reporters in Canberra.

Lowe said the ACCC expected the suppliers to provide appropriate support to consumers, including advice about arranging a refund.

“We urge customers who own any of the products to stop using them immediately and place the sand in a heavy-duty plastic bag and double tape it securely and keep it out of reach of children,” she said.

“When doing so, in an abundance of caution, customers should take precautions such as a wearing disposable gloves and a mask.”

Asbestos can’t be thrown out in general waste, but the Asbestos and Silica Safety and Eradication Agency website provides a list of special disposal facilities across the country.

Asbestos-contaminated mulch prompted the closure of schools, hospitals and parks in Sydney in 2024, while historic dumping and legacy contamination was blamed for traces found at parks in Melbourne’s west.

–with AAP