Your Health

The Hidden Risk in Store-Bought Slime

Avoid this hazardous ingredient with our own DIY slime recipe

Slime seems to be the hottest new toy for kids. They love that it’s a tactile toy they can squeeze and smash. But before you rush out to buy a new tub of gooey slime on your next shopping trip, have you ever wondered what’s actually in it? Turns out, there’s a not-so-kid-friendly ingredient lurking in many slime products sold in stores, as well as in some DIY kits and recipes.

What’s So Bad About Boron?

Boron is a chemical commonly used in many brands of slime, DIY kits, and some DIY recipes to give it that rubbery texture. While it may feel fun, it’s actually not great for our health. Boron is an acute eye, respiratory tract, and nasal irritant and is harmful if swallowed (1). If ingested, it can also cause nausea and vomiting (2). Long-term exposure to boron can also cause negative reproductive health effects (3, 4). The problems with boron don’t stop once you throw slime away either. It turns out that boron lasts a long time in the environment and has hazardous effects on aquatic life (5).

To make matters worse, there’s a lot more boron in slime than there should be. The U.S. Public Interest Research Group (PIRG) recently tested different brands of slime and found concentrations as high as 4700 parts per million (ppm) of boron, (6) which is more than fifteen times the allowable level for toys sold in the European Union (300 ppm for sticky/liquid toys) (6). Canada, Jordan, and the United Arab Emirates have even instituted policies limiting or banning boron in children’s toys (6).

Safe Slime

Luckily, it’s easy to make your own boron-free slime. We like this recipe for full-proof slime that substitutes boron/borax (a boron compound that’s found in a lot of other slime recipes) with cornstarch and school glue. We guarantee your kids will still have hours of fun with this non-toxic slime!

Fluffy Volcano Slime

  1. Pour 1/4 cup white school glue and a 1/2 cup of cornstarch in a bowl
  2. Add 3 drops of food coloring (optional)
  3. Mix well
  4. Knead it with your hands for 10 minutes
  5. Heat it in the microwave for 20 seconds
  6. Let it cool, then knead it for another 10 minutes (7)

References

2. https://www.epa.gov/sites/production/files/2014-09/documents/health_effects_support_document_for_boron.pdf

3. https://toxnet.nlm.nih.gov/cgi-bin/sis/search/a?dbs+hsdb:@term+@DOCNO+328

4. https://www.epa.gov/sites/production/files/2014-09/documents/health_effects_support_document_for_boron.pdf

5. https://pubchem.ncbi.nlm.nih.gov/compound/Boron

6. https://uspirg.org/sites/pirg/files/reports/WEB_USP_Toyland-Report_Nov18_2-1.pdf

7. https://www.cnet.com/how-to/make-slime-without-borax/