PARENTS should be wary that some children's slime products may contain higher than recommended levels of a chemical, a consumer watchdog has said.
Which? said that parents should be able to buy toys without being fearful that they could cause their children harm.
The consumer body called for "fundamental changes" to the product safety system after it found that some products had higher than recommended levels of boron.
Slime and slime products have become increasingly popular among youngsters.
Compounds of boron can be used in eye drops, mild antiseptics, washing powders.
Which? said boron is found in borax, a common ingredient in slime that helps to create its "stickiness".
A European Union safety directive sets out how liquid or sticky toys should contain no more than 300mg/kg of boron.
The consumer champion set out to investigate whether some children's slime products contained the recommended safe levels. It found that eight out of 11 toy slime products tested exceeded limits.
Which? said that Toysmith Jupiter Juice had more than four times the permitted level of boron with 1400mg/kg.
This was followed by CCINEE Pink Fluffy Slime, which was found to contain 1000mg/kg, and Cosoro Dodolu Crystal Slime Magic Clay, which was found to 980mg/kg, Which? added.
It said that all eight products that failed were purchased on Amazon.
One product purchased on the online marketplace, Hulk Green Halloween Slime, met the standard.
The products which did not meet the standard have been removed from Amazon's website.
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."
