However, EWG cautioned consumers against waiting for President Donald Trump's Environmental Protection Agency (EPA) to take any action in light of the startling study.
Oats are the basis of many favorite children's snacks, including Cheerios and other baby finger-food cereals.
The World Health Organization has classified glyphosate as a "probable human carcinogen", though the product's harm to humans is still being debated.
In a groundbreaking decision, a terminally ill California man won a $289 million settlement on Friday from the controversial chemical manufacturer Monsanto after a judge agreed that the company's weed killer, Roundup, caused the man's cancer. Then, using a strict standard the group developed, it found elevated levels of glyphosate in 31 of them.
Husband detained in case of missing pregnant woman and 2 daughters
An Endangered Missing Alert has been issued for Shannan Watts (age 34), and her two daughters, Celeste and Bella Watts (ages 3&4). A judge has ordered a Colorado man accused of killing his pregnant wife and two young daughters held in jail without bail.
The amounts of glyphosate found in the products typically measured in the hundreds of parts per billion, or less than 0.000001 per cent. According to the U.S. Geological Survey, more than 200 million pounds of glyphosate are sprayed on crops each year.
Thirty-one of the breakfast foods were found to contain levels of glyphosate that were higher than the level that EWG deems safe for children. Some of the products with the highest concentrations of the herbicide include Quaker Old Fashioned Oats, Cheerios Toasted Whole Grain Cereal and Back to Nature Classic Granola. "We're saying a pesticide like this which has the ability to increase the risk of cancer has no place in food an particularly not foods that are marketed to children", said Walker. One sample of Quaker Oats had 1,300 parts per billion. Farmers will spray the weed-killing chemical on crops, such as wheat, oats and lentils, before harvest.
"The challenge here is that the story seems pretty clear: Glyphosate is bad, and it is in a lot of food products", says Tim Calkins, clinical professor of marketing at Northwestern University's Kellogg School of Management.
In a statement to FOX Business, a Home Depot spokesperson said the company follows all regulatory guidelines regarding the sale of Roundup, and that they plan to continue to sell these products going forward. The nonprofit wants the EPA to make its standard more stringent: "Our general stance is pesticides and herbicides really don't belong in children's food", says Alexis Temkin, a toxicologist at EWG. "Any levels of glyphosate that may remain are significantly below any limits and well within compliance of the safety standards set by the Environmental Protection Agency (EPA) and the European Commission as safe for human consumption".
Bayer shares registered yet another sharp decrease on Thursday (16 August), dropping as much as 6.5% in Frankfurt to hover near the 76 euros level as investors fear the German chemicals and pharmaceuticals giant may face numerous litigations in the United States after its controversial merger with Monsanto.