Just like Play Doh way back when, toy slime can keep your kids occupied for hours on end. They will splat in on the table - maybe even the carpet if you're unlucky - let it sludge through their hands and just generally get it everywhere.
But it keeps them entertained so they can keep it, right? Wrong, apparently.
According to the MailOnline, consumer watchdog Which? found that some slime products contain potentially unsafe levels of the chemical, boron, which in excessive levels causes short-term diarrhoea, vomiting and cramps.
Boron is found in the compound borax - the stuff that is used to give the slime a thick and sticky consistency.
The gooey phenomenon has blown up over the past year with kids all over playing with it but now 11 different versions that are on sale via Amazon, Smyths and The Works have been tested.
Serious concerns were raised as eight out of the 11 products, showed unsafe levels of the chemical.
Slime Toy also failed the test. Credit: iBase Boy/Amazon
The eight products that were flagged up exceeded the EU safe limit of 300mg/kg and the worst offender was Toysmith Jupiter Juice which had four times the permitted level of boron at 1,400mg/kg.
Next up was CCINEE Pink Fluffy Slime, which contains 1000mg/kg, followed by Cosoro Dodolu Crystal Slime Magic Clay, which contains 980mg/kg.
All the slime toys that failed the tests could be purchased on Amazon, who told The Sun that they have since removed all of them from sale.
Only one of the products purchased from Amazon met the standard whereas The Works and Smyths both sell safe slime which is within the required limit.
Jupiter Juice in pink, from Toysmith, was found to be the worst offender. Credit: Toyco
Nikki Stopford, Director of Research and Publishing at Which?, said: "If you have school-age kids you're probably very well aware of the latest slime craze sweeping the playgrounds. Kids love it.
"Parents buying slime for their children should have peace of mind that these toys are safe, so they will be shocked to find that the health of their children could be put at risk by these slimes.
"There must be fundamental changes to the product safety system.
"Manufacturers must stop making unsafe products and the Government and retailers simply have to do a far better job of getting anything identified as a risk off the shelves and out of people's homes."
Following these alarming results, Which? is advising parents to approach all slime with caution, as many have minimal safety labeling or information on the ingredients.
Goopy Slime, on sale at The Works, was also found to contain safe levels of the chemical. Credit: The Works
It has been reported that some of the slimes self-certified the packaging with a CE mark, suggesting the product is safe, despite the fact that boron levels were too high.
Which? has now passed its findings to the Office for Product Safety and Standards (OPSS), asking for 'fundamental changes' to the product safety.
Featured Image Credit: PA