Viral squishy toy microwave stunts driven by social media are resulting in children suffering severe burns.
One manufacturer has asked Australian Border Force to stop counterfeits from entering the country.
Experts say most of the toys are safe if they are used as intended.
They are soft, often sparkly, a sensory delight and the current must-have for children around the world.
But what the viral squishy toys are made of is often not disclosed and a social media trend has put dozens of Australian children in hospital with serious burns.
Squishies are soft, squeezable toys usually made from a thermoplastic rubber outer shell and filled with polyvinyl alcohol (PVA), maltose — a sugar-like substance — gels, beads and other materials.
They come in a range of shapes and sizes, from cubes to capybaras, and can be purchased anywhere from large department stores to small pop-up shops and online.
Demand for the toys has driven a rise in counterfeits that often do not disclose their contents, leading one manufacturer to ask the Australian Border Force (ABF) to stop them from entering the country.
But even when the toys disclose their makeup and undergo safety testing, they are not risk-free.
A viral online trend has children microwaving the squishy toys, resulting in serious injuries.
A Sydney Children's Hospitals Network spokesperson said between January and September this year, 11 children were referred to the Burns and Plastics Treatment Centre at the children's hospital at Westmead for burns caused by squishy toys.
"Children were aged between 6 and 12 years old with burns ranging from mid to deep burns on the face, neck, chest, arms and hands," the spokesperson said.
"Some children sustained burns that required skin grafts and longer-term scar treatment."
Queensland Children's Hospital paediatric emergency physician Veevek Thankey said that, since April, he was aware of at least 13 burn cases linked to squishy toys being heated.
"The biggest issue that we've seen is actually the burns themselves as opposed to the actual reactions to the content that's present within these toys," he said.
He said most of the issues have been with burns to the hands or face, which require "intensive management".
Dr Thankey added that because the gel liquid becomes sticky, burns can occur fast.
If an incident occurs, he said the most effective first aid was to remove any of the gel from the skin and place the affected burn area under cool running water for 20 minutes.
A Tasmanian Department of Health spokesperson confirmed its burns unit was aware of a small number of injuries caused by these toys.
Other health jurisdictions were unable to confirm if there were any reports of injuries related to the toys.
The sudden popularity of the toys has led to a boom in counterfeits.
It is something Schylling, the manufacturer behind NeeDoh, has taken seriously, asking the ABF to seize counterfeit products entering the country.
William Valentine, the distributor of NeeDoh in Australia, confirmed it had taken steps to combat counterfeit products, including registering its intellectual property with the ABF Notice of Objection scheme.
"Counterfeit products don't just infringe on our intellectual property — they bypass the rigorous design, manufacturing, quality control and independent safety testing that authentic NeeDoh products undergo before reaching consumers," managing director Benjamin Halls said.
"That's why we take the growing issue of counterfeit toys so seriously."
He said they were also working with local counsel to identify sellers of counterfeit products and take appropriate legal action.
Consumer watchdog the Australian Competition and Consumer Commission (ACCC) confirmed it has been liaising with several domestic and international regulators in relation to squishy toys, along with online marketplaces and businesses.
It said there were mandatory standards regarding the levels of lead and other chemicals contained in products, and warned of consequences if businesses fail to comply.
In the UK, the Office for Product Safety and Standards issued a recall for Samsons Cash and Carry Squeezy Dumplings after they were found to contain an excess concentration of benzene — a chemical linked to leukaemia.
Thousands of toys, including squishy toys, were seized in shops across North East Lincolnshire. Another 81 were seized from a retailer on the Isle of Man.
In the US, the Consumer Product Safety Commission (CPSC) has also issued a warning about counterfeit squishy toys, with 55 shipments of noncompliant squishy toys stopped at US ports, preventing more than 355,00 units from entering the country.
A professor of analytical chemistry at RMIT, Oliver Jones, said that while the unknown chemical makeup of squishy toys can be concerning, they were most likely made from the same materials.
"It's just that the manufacturing quality and the amounts [of chemicals] that might be left over in the final product could be worse if you've got one of these counterfeit ones that have been made at short notice without proper oversight and brought onto the market here," he said.
He said other qualities like the thickness of the material on the outside of the squishy toy and its robustness were also concerns for knock offs.
The ACCC recommends consumers avoid toys with strong chemical smells, weak seams, loose beads and leaking parts and to look for safety information including ingredient or material information.
However, Dr Jones said most of these toys were made at a quality standard.
"If you bought it from a reputable shop … and it doesn't smell and it's got listing of what's in it and so forth, I wouldn't be particularly worried as long as it's used in the way it's intended," he said.
"Even if it's like the best quality made toy in the world, if you put it in the microwave, that's an extra risk.
"And to be a bit careful about leaving them in hot cars just to be on the safe side.
"We just have to be careful that when something does go wrong, then we learn from it. And if we can improve safety with better data on what's in the toy and how it's been manufactured, that can't be a bad thing."