If you don’t have children, you may well be unaware that slime is a thing. A huge thing, and many kids love to spend hours making slime using a plethora of internet recipes. But concerns have been raised that it can contain potentially toxic levels of chemicals. Should parents be worried about their children playing with it?

A report by consumer group Which? has found that some slimes bought online in the UK contain up to four times the permitted concentration of an element called boron, in the form of …