To put it into perspective, says Andrew Stolbach, a medical toxicologist for Johns Hopkins Medicine, “asbestos is a rock that’s shaped like a fiber. And it sounds really cool! You know, you spray it onto houses and make them fireproof. But as we know, that went very wrong.” The mineral, which has been used in the United States for hundreds of years in insulation, car parts, cement, and more, was found to be harmful in the early-20th century. It has been banned in 55 countries.

The United States is not one of these countries. In the 1970s, the Environmental Protection Agency introduced regulations on the import and use of asbestos, and while its use has been significantly curtailed, it has only been entirely banned from six product categories. And the rules around the chemical are likely to change under Donald Trump’s administration, which introduced a proposal in June that would overturn a ban on new uses of asbestos and institute something called a “Significant New Use Rule.” This rule would allow the development of new products containing asbestos, after the EPA evaluates the new use for any potential safety concerns. The EPA contends that its proposal would protect consumers by requiring companies to receive approval before manufacturing or importing asbestos-containing products. Advocacy groups and former EPA officials, however, have erupted in opposition to new health hazards.

A 2015 study estimates that about 9.9 million people a year are still killed from asbestos poisoning globally, with the United States leading the charge among countries with good data: At least 2,500 Americans die from the effects of exposure every year.

It may seem odd that crayons would contain asbestos, given that the chemical is typically found in housing-construction materials. But the asbestos isn’t a component of a crayon so much as it is a byproduct of processing talc, a widely available material that’s also found in cosmetics, baby powder, and deodorant. “Talc is mined in places where asbestos is co-occurring,” says Cook-Schultz. “So what you have to do is refine the talc, and then you test it, and then you put the talc in your product, your crayon, your makeup. But some of these companies aren’t doing enough of a process to refine the asbestos out of the products.” A lot of talc mines and refineries are in China, says Cook-Schultz. And while there are refineries that adequately remove traces of asbestos, regulations are not as stringent as they are in the United States.

When asbestos is found in products, it’s often found in trace amounts, which, Stolbach says, isn’t dangerous for most people. In that case, the United States Consumer Product Safety Commission, or CPSC, might issue a voluntary recall to the manufacturers and retailers with the product on its shelves. The U.S. PIRG has requested a recall of the crayons, which the CPSC has not yet issued.