Report: Asbestos, chemicals found in Playskool crayons, school supplies sold at Dollar Tree, Amazon

Testing on the crayons by the U.S. Public Interest Research Group, or PIRG, found trace amounts of asbestos, a cancer-causing carcinogen, in the product. The testing also found that blue three-ring binders, made by Jot and also sold at Dollar Tree stores, tested positive for phthalates, a group of hazardous chemicals used in plastics manufacturing that have been linked to asthma, childhood obesity, and lower IQ scores.

In all, U.S. PIRG sent 27 school supplies to an independent laboratory to test for dangerous chemicals.

The test results also found BTEX chemicals, like benzene and toluene, more dangerous carcinogens, in dry-erase marker made by Expo and The Board Dudes.

The group also tested two children's water bottles, which tested negative for lead. The lead tests follow a recall by the Consumer Product Safety Commission on two other brands of children's water bottles, Reduce Hydro Pro Furry Friends water bottle, which was sold at Amazon, Costco and GSI Outdoors, and children's water bottles sold at L.L. Bean.

Officials with U.S. PIRG are recommending a voluntary recall of the supplies found to contain harmful chemicals and toxins.

The group's Back-to-School guide also lists supplies that are chemical-free.