Once one craze disappears into obscurity, up pops another one. This time, the latest craze gripping the nation's children is slime.

Okay, so this is nothing new I hear you cry, slime has been a kid's favourite since the 1970s.

However, thanks to the wonderful world of You Tube, video tutorials showing how to make the substance have taken over the internet in the past year.

The fun material can be made at home offers a fun, arty activity for young children and teenagers alike.

Slime is the latest craze sweeping the nation

However parents should know that making it isn't without risks due to the inclusion of potentially dangerous chemicals in some guides, reports the Chronicle

So what exactly is slime? And how can you make sure your kids are staying safe?

Here's everything you need to know.

What is slime?

Slime is gooey substance that kids can make at home using a variety of household items, a bit like play-doh.

Its popularity has been fuelled by You Tube tutorials, some of which have been viewed tens of millions of times.

Slime comes in a 101 different varieties: glitter slime, smelly slime, stretchy slime, colourful slime.

There are lots of different methods to make it but most use PVA glue, water and food colouring.

Children are loving this sticky craze

What is Borax?

Some online recipes for slime suggest using a substance called Borax.

Borax is a chemical that is usually found in laundry and cleaning items in a powder form.

It is also called sodium borate, sodium tetraborate or disodium tetraborat.

Why should parents be worried about Borax?

The European Chemicals Agency (ECHA) has classified it as a serious health hazard, saying "this substance may damage fertility or the unborn child and cause serious eye irritation".

A 10-year-old from Prestwich suffered "serious chemical burns" to her hands after making the substance with the help on an online tutorial last year.

Deejay Jemmett suffered gruesome blisters and peeling after using fabric detergent as part of the mix, the Manchester Evening News reported.

Can you make slime safely without Borax?

Yes you can, there are plenty of safer versions which don't use caustic chemicals.

YouTuber Jelly Rainbow's safe version looks like this: PVA glue; Food colouring; Glitter; Water; Salt.