If you're buying back-to-school supplies, stay away from crayons made by Playskool. Dollar Tree stocks the brand, and recent testing showed they contain trace amounts of the cancer-causing substance asbestos.

Dangers of Asbestos Exposure

Asbestos is a naturally-occurring substance that has a number of commercial and industrial uses. In the past it has been added to roofing material, paints, plastics and other products. In the 1970's the Consumer Product Safety Commission banned its use in products like hair dryers and drywall because when asbestos is broken, tiny asbestos fibers can be inhaled. The fibers accumulate in the lungs and can cause inflammation, breathing problems and cancer. The Environmental Protection Agency has linked asbestos exposure to mesothelioma.

Asbestos has been completely banned in 60 countries, but it's only restricted in the United States. Even though it has been linked to significant health risks, it's not illegal.

Why Is Asbestos in Crayons?

The U.S. Public Interest Research Group conducts annual tests of toys and school supplies. They found trace amounts of asbestos in Playskool crayons. The testing agency said it wasn't clear whether the asbestos in the crayons was enough to be dangerous, but pointed out that children often eat crayons.

Not The First Time

When the same research group tested crayons in 2015, several other brands contained asbestos fibers. Disney Mickey Mouse Clubhouse Crayons and Nickelodeon Teenage Mutant Ninja Turtles Crayons also contained the substance.

A Dollar Tree spokesman says they have independent testing for all of their school supplies and other children's products, and that their certified lab testing did not reveal a detectable amount of asbestos.

PIRG is recommending Hasbro-owned Playskool issue a recall for the crayons. They found other brands to be asbestos-free, so there are plenty of non-toxic options available. If you're concerned about other school supplies, see the PIRG report here.