Rainbow sand from Educational Colours and coloured sand from Creatistics have been recalled because Tremolite - a naturally occurring asbestos - has 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.
"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.
The principal of Kapakapanui School in Waikanae said they had removed containers of the coloured sand from their junior block after receiving notification from the Ministry.
Craig Vidulich said the sand had been used in the school for about a year.
"It's a creative sand product that the kids use in their discovery time - when they play with it in their little sand trays. It's all been removed."
He said the school had acted quickly to close off classrooms and redirect activities.
"As of today we've actually got six classes who are working in our hall and it's a beautiful sunny day in Waikanae today, so they're outside as well, and they're in our library. Our teachers have pivoted and done an amazing different program for today to keep everyone out of the block."
Vidulich said asbestos specialists had taken samples from the school and they were expecting test results early next week.
"At this point we don't know if asbestos is in the product, so it's really a bit of a safety measure at the moment."
Auckland Kindergarten Association chief executive Pauline Winter said two of the association's 112 early learning centres had closed.
"Most of our 112 sites had no coloured sand products, some had it in sealed containers, four had limited product which was cleared by specialists last night, and two kindergartens are closed waiting specialist cleaning.
"We expect to have those open on Monday."
