How To Make Your Own Non-Toxic Slime

A study in the UK has identified 11 slime brands that contain unsafe levels of Boron. The Tot Green Living Expert, Aida Garcia-Toldeo discusses the findings and shares her recipe for Boron-free slime.


Slime is having a moment. Kids all around the world are obsessing over slime. Slime-making parties are all the rage, entrepreneurial kids are selling slime, and parents are trying to keep up by buying huge amounts of slime and slime-making ingredients.


The chemicals behind all the slimy fun

It’s hard to find a kid who doesn’t like or isn’t fascinated with it. Slime is one of those rare ‘toys’ that can entertain children of all ages for hours. It’s the perfect toy. Or so you’d think. Unbeknownst to many parents and kids, some slime is actually exposing our children to harmful chemicals that, in some cases, have resulted in serious health effects.  

Which?, a U.K.-based organization, this week published the results after testing 11 popular slime products. They found eight that contained unsafe levels of boron. All of the tested slime products were purchased online on Amazon.

According to Which?, the permitted level for boron in all children’s toys is 300mg/kg. Of those tested, the worst was Toysmith’s Jupiter Juice, which contains 1,400mg/kg, or four times the safety limit of boron. CCINEE Pink Fluffy Slime and Cosoro Dodolu Crystal Slime Magic Clay followed, with unsafe levels of boron. 

One slime product, Mini Bucket Putty, was found to have more than the allowed legal limits of boron for slime. However, the company claimed that “its product should officially be declared a putty, not a slime, and was therefore within the safety limits for boron.” 

While the slime products that were found by Which? to contain high levels of boron are not longer being sold on Amazon, the reality is that many other slime products that have not been tested for safety are still being sold online and in stores everywhere.

What exactly is boron?

Boron is a mineral found, in food and the environment. It can be found in items containing boric acid and boron oxide. Boron is what gives slime products its stickiness.  

If used properly, diluted boron can be safe, but not as a toy ingredient for children. Exposure to excessive levels of boron can cause symptoms such as irritation to the skin, diarrhea, vomiting and stomach cramps. According to the EU, contact with very high levels of boron could impair fertility and harm fetuses in pregnant women.


Is store-bought slime safe?   

Yes, it can be perfectly safe (the Which? investigation identified three brands with safe levels of boron), but it can be a challenge to identify safe, non-toxic slime. Most products have minimal safety labeling and information about ingredients. Some products carried the CE safety mark, despite carrying higher than recommended boron levels. 


What about homemade slime?

If your child loves slime, you might be tempted to look online and find a homemade slime recipe, thinking that if you are making it at home with familiar ingredients, it must be safe. Unfortunately, there have been various cases of kids getting third degree burns after mixing homemade slime using Borax (which contains boron) as the main ingredient.

However, fear not, there are child-friendly recipes for boron-free slime!  

Just remember that you want to avoid recipes that contain the following ingredients, since they all contain boron:

  • Borax
  • saline solutions
  • contact lens solution
  • liquid starch
  • eye drops

We tried a couple recipes at home and had success with this easy to make at home Boron-free slime. And the best part is that you probably already have all of the ingredients in your kitchen!