If your child's obsessed with making slime, there's an ingredient you need to be careful of.

Smart phones and tablets come and go, but there’s one kids’ toy that has stood the test of time.

The novelty of slime – better known by some parents as the sticky sh*t your kids won’t put down – never wears thin. Give a child a pot of the green stuff and they’ll be occupied for hours, exploring just how many places around the house it can go.

While garden variety slime products can be bought from most toy stores, many families are choosing to make their own. You know, the whole killing two birds with one stone thing of saving money and keeping the kids entertained.

But when it comes to doing it yourself, there’s one ingredient you need to be careful of.

Google ‘how to make slime’ and you’ll see the ingredient ‘borax’ pop up. As well as being used by some to make slime, it’s also used in other domestic products you’d really rather not involve your children with. Like pesticides, flame retardants, laundry detergent and teeth bleaching products, to name a few.

In small quantities, borax is not acutely toxic, but ingesting large amounts can cause nausea, vomiting, and diarrhoea. Considering children have a tendency to put things in their mouths, this isn’t ideal.

Before you panic about how many weeks of pocket money will be spent on store bought slime, there are ways to make it at home that won’t put your child’s safety at risk.

Image: Supplied.

One popular method involves using cornstarch. Put a bunch of cornstarch into a bowl, and slowly mix through water until the mixture reaches the desired consistency. Then, simply add green food colouring for the full effect. Here's a video tutorial to see how it's done.

You can also try making slime with fibre, specifically, powdered psyllium. Yes, the same stuff you sprinkle on your porridge to keep things... regular. You can pick this up from any health store, just make sure it's psyllium hydrophilic mucilloid.

This method works by microwaving the powered psyllium and water (with food colouring) and then cooling it continually until it reaches the desired consistency. Here's the full tutorial.

The best thing about either of these alternative recipes is, technically, it can be eaten (* please note: in small quantities) - it can even taste good if you add some flavoured drink crystals, which will officially will make you the coolest parent ever. Of course, that's only until something cooler comes along, but we'll take what we can get.

LISTEN: For more imperfect parenting advice, get This Glorious Mess in your ears. It's brilliant...