The Ministry of Education says nearly 60 schools and early childhood centres have contacted them over possible asbestos contamination from recalled coloured play sands.
Rainbow sand from Educational Colours and coloured sand from Creatistics were recalled because Tremolite — a naturally occurring asbestos — had been found in samples during lab testing.
Head of operations and integration Sean Teddy said schools were told not to attempt to clean it up, but leave the area and close off access to affected spaces.
"We've been contacted by around 30 schools and 30 early childhood services from around the country, and we are working with them to validate if the product they have on site is the product that is being recalled, as well as if the product they have is in active use or not.
"We will have a better understanding of the number of schools and early learning services affected by the recall, and how they are responding, by the end of the day Friday."
Asbestos contamination had been found in similar products in Australia.
Earlier in the week the Ministry of Business Innovation and Employment (MBIE) said people needed to stop using the products immediately.
"We urge anyone who has bought these products, either for personal use or potential use in a school or other setting to act immediately," said Ian Caplin, MBIE product safety spokesperson.
"Stop using the sand, contain it, secure it in a safe place and arrange for safe disposal through licensed professionals, a list of these is available on the WorkSafe website."
Caplin said people should avoid trying to clean any loose particles themselves
"It's not a question of hoovering it up and chucking it in a waste bin, call an expert."
The sand was sold at Paper Plus, Hobby Land, NZ School Shop, Office Products Depot, Discount Office, Acquire, and Qizzle, Modern Teaching Aids, Creative Classrooms Ltd and ACME Supplies.
MBIE said it may have also been sold online.
RNZ had been in touch with a number of asbestos removal firms who said they had been notified of the product by WorkSafe, and were awaiting further information before formulating plans to address potential contamination.
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