Slime is the latest annoying trend with kids, they make it, sell it and play with it with their friends, but could it be toxic?

Consumer watchdog Which? Has found that some of the ingredients used to make slime could be very harmful to your child's health.

Some slime products have very high levels of the chemical boron, which in excessive levels causes short-term bouts of diarrhoea, vomiting and cramps.

Boron is used in the process of making slime because it makes it thick and sticky.

The European Chemicals Agency has now warned that boron may damage fertility and cause serious eye irritation and could cause harm to unborn children if pregnant women come into contact with it.

Nikki Stopford, director of research and publishing at Which?, said: ‘Parents buying slime for their children ... will be shocked to find that the health of their children could be put at risk.’

Home-made slimes have previously raised concerns over borax, with reports that children have suffered injuries after trying to copy slime recipes found online.

But Which? is now calling for ‘fundamental changes’ to the product safety system after its tests.

The worst slime tested was pink Toysmith Jupiter Juice, which had more than four times the permitted level of boron at 1,400mg/kg.

This was followed by CCINEE Pink Fluffy Slime, with 1,000mg/kg, and pink Cosoro Dodolu Crystal Slime Magic Clay, which contained 980mg/kg. All of the slimes exceeding the limit were available on Amazon.

These batches have been removed from Amazon, but Which? is advising parents to think before they buy as they could be putting their children in danger.