Toys R Us and Amazon were among the retailers that pulled asbestos-containing crayons from their shelves in 2015. (iStock)

A popular brand of crayons contains toxic levels of asbestos, according to a consumer advocacy group that is calling on retailers such as Dollar Tree and Amazon.com to pull the items from their shelves.

The U.S. Public Interest Research Group (U.S. PIRG) Education Fund says Playskool crayons tested positive for asbestos, which can lead to lung cancer and mesothelioma if inhaled or ingested. The group tested 36-packs of crayons purchased at a Dollar Tree store in Chicago but noted that they are also being sold online at Amazon, eBay and DollarDays.com. (Jeffrey P. Bezos, the founder and chief executive of Amazon, owns The Washington Post.)

"There is no reason to be exposing kids to a known carcinogen, especially in crayons,” said Kara Cook-Schultz, toxics director for U.S. PIRG.

A spokeswoman for Playskool’s parent company, Hasbro, said it is conducting a “thorough investigation” into the claims. Leap Year Publishing, the Massachusetts-based manufacturer of the crayons, said it is also reviewing its lab tests.

Dollar Tree executives, meanwhile, said independent tests have indicated that its crayons do not contain asbestos.

“The safety of our customers and associates is our top priority,” Randy Guiler, vice president of investor relations, wrote in an email. “We are aware of the report and have since re-verified that each of the listed products successfully passed inspection and testing.”

Amazon, eBay and DollarDays.com did not immediately respond to requests for comment.

The findings come three years after a report from the Environmental Working Group Action Fund found that four brands of crayons manufactured in China contained toxic asbestos fibers. Amazon, Toys R Us, Party City and Dollar Tree stopped selling the crayons as a result. (The affected brands were Saban’s Power Rangers Super Megaforce Crayons; Disney Mickey Mouse Clubhouse Crayons; Nickelodeon’s Teenage Mutant Ninja Turtles Crayons; and Amscan Crayons.)

Although federal laws regulate the amount of asbestos in drinking water, schools and some consumer products, there are no regulations on the amount of asbestos allowed in children’s products, according to Cook-Schultz.

The group also tested five other crayon brands — Crayola; Target’s Up & Up; Cra-Z-Art; Disney Junior Mickey and the Roadster Racers; and Roseart — that were found to be asbestos-free.

U.S. PIRG publishes an annual report on toy safety, which has led to more than 150 product recalls and regulatory actions over the past 30 years. In November, Target pulled two types of fidget spinners from its shelves after the group found that they contained as much as 330 times the federal legal limit for lead in children’s products.

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