(Meredith) -- Some crayons sold at a popular discount store may contain toxic chemicals, according to a new report released by a consumer advocacy group.
The U.S. Public Interest Research Group (U.S. PIRG) said in its annual report on the safety of school supplies that Playskool crayons tested positive for trace amounts of asbestos -- a substance that can cause cancer and mesothelioma if inhaled or ingested.
The group tested 36 packs of the crayons purchased at a Dollar Tree in Chicago, but noted they are also being sold at Amazon, eBay and DollarDays.com.
"It’s completely unnecessary for crayons to contain asbestos," Kara Cook-Schultz, U.S. PIRG education fund toxics director, told ABC News. "We know how to produce crayons without asbestos and most crayons are free of asbestos."
Dollar Tree released a statement disputing the findings:
The safety of our customers and associates is our top priority. Our company utilizes a very stringent and independent testing program to ensure our supplier products meet or exceed all safety and legal standards. We are aware of the report and have since re-verified that each of the listed products successfully passed inspection and testing.
Hasbro, Playskool's parent company, said it's investigating the report's claims.
"Product and children’s safety are top priorities for Hasbro," the company said. "We are conducting a thorough investigation into these claims, including working with Leap Year, the licensee of the product."
In 2015, the Environmental Working Group Action Fund found that four brands of crayons manufactured in China contained asbestos. As a result, retailers like Amazon, Toys R Us, Party City, and Dollar Tree stopped selling the products.
According to U.S. PIRG, there are no current federal laws regulating the amount of asbestos allowed in children’s products.
Aside from the Playskool brand, the group tested five other crayon brands which were found to be asbestos-free. Those brands include Crayola, RoseArt, Up & Up by Target, Cra-Z-Art, Roadster Racers and Disney Junior Mickey.
“Based on our testing, we know that most manufacturers make safe school supplies. We’re calling on the makers of unsafe products to get rid of toxic chemicals and protect American schoolchildren,” said Danny Katz, with U.S. PIRG.
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