The nationwide recall of coloured play sands has widened again, after testing found asbestos in multiple Kmart Magic Sand products, prompting warnings that parents, schools and early learning centres should "stop using them immediately".

The Ministry of Business, Innovation and Employment (MBIE) said four products sold by Kmart New Zealand - including three Magic Sand colour sets and a sandcastle-building kit - tested positive for tremolite, a form of asbestos associated with higher cancer risks at low exposure levels.

The findings expand an already significant recall that began last week, when rainbow sand products used widely in schools and childcare centres were found to be contaminated.

MBIE product safety spokesperson Ian Caplin said he understood how alarming the discovery would be for families.

"We appreciate that the presence of asbestos in products that are used by children will be concerning to parents and caregivers," Caplin said. "Stop using them immediately, secure them safely, and contact your local council for advice on where and how to dispose of the contaminated material safely."

The contaminated Kmart products include:

• 14-piece Sandcastle Building Set
• Blue Magic Sand
• Green Magic Sand
• Pink Magic Sand

The newly identified products are in addition to the previously recalled sands from Educational Colours and Creatistics:

• EC Rainbow Sand (1.3kg)
• Creatistics Coloured Sand (1kg)

Educational Colours Rainbow Sand has been recalled. Photo: Supplied / Product Safety NZ

Thousands of children potentially exposed as schools continue to close

The Ministry of Education had been fielding a rapidly growing number of calls from schools and early childhood services, with more than 120 facilities now reporting they have used one of the recalled sand products.

At least seven centres have closed classrooms so licensed asbestos specialists can assess potential contamination, with more likely as checks continue.

Head of operations and integration Sean Teddy said schools had been told not to vacuum, sweep or attempt to clean up any coloured sand themselves.

Creatistics Coloured Sand is sold in various colours. Photo: Supplied / Product Safety NZ

"If the sand is loose or in use, leave the area immediately and block it off," he said. "We know this will be unsettling for parents, and we're encouraging them to contact Healthline if they have concerns."

Some schools used the products indoors for sensory play, raising the risk of sand becoming airborne. Kapakapanui School in Waikanae relocated six classes to the hall and library while specialists carried out testing. Two Auckland Kindergartens remain closed.

WorkSafe earlier confirmed tremolite is part of the amphibole family of asbestos - a type known for its straight, needle-like fibres and stronger association with cancer and autoimmune illness.

More Kmart products could test positive

Caplin said Kmart had "acted with urgency" in issuing its recall, but warned that more products across the market may yet be implicated.

"Proactive testing of similar products is underway," he said. "We cannot say for certain whether these are the only contaminated items."

Similar sand products in Australia have also tested positive for asbestos, raising concerns about shared international supply chains.

What households should do

MBIE has issued instructions for consumers:

• Stop using the product immediately and keep children away.
• Place the sand in an airtight container, then double-bag it in thick plastic and label it "Asbestos-Contaminated Material."
• Do not put it in household rubbish, and do not vacuum or sweep any loose sand.
• Contact your local council for safe disposal.
• Once the product is secured, contact the retailer for a refund under the Consumer Guarantees Act.

People who have already handled the sand do not need urgent medical attention, MBIE said, but should call Healthline or speak with a GP if concerned.

Workplaces and schools urged to treat contamination seriously

Workplaces using coloured sands - including after-school programmes, arts centres and classrooms - have been told to immediately stop all use, evacuate any area where the sand is loose, and contact a licensed asbestos assessor.

Staff who were handling the product should remove themselves to a well-ventilated, sand-free area, and clothing worn during exposure must be disposed of as asbestos waste, MBIE said.

Education facilities must also notify the Ministry of Education if the sand has been used on-site.

This story was originally published by RNZ