Consumer's Union put 19 products under the microscope to test for levels of the chemical bisphenol A, or BPA.
What it found was a wide range of results -- little or no BPA in some juice boxes and infant formula packaged in paper, but what Consumer's Union considered high levels in a number of canned goods, including Del Monte green beans and Progresso Vegetable Soup.
"Our studies show that BPA is actually in the food itself," Urvashi Rangan, director of technical policy at Consumer Reports, told "Good Morning America." "We don't think that consumers should be continually exposed to levels and levels that are already causing harm in animals."
Rangan said the study found levels of BPA in nearly all of the canned foods they tested. But the fact that the levels of BPA varied so widely surprised Rangan.
"[It] suggests that consumers really don't know what they're getting when pulling a can off the shelf, potentially exposing themselves to harmful levels," Rangan said on "GMA."
BPA is used in the lining of tin cans and in plastics such as baby bottles.
Some studies have shown it may be linked to reproductive problems, or increased risk of cancer or diabetes.
But the Grocery Manufacturing Association said in a statement, "The public should not be alarmed."
Robert Brackett, the Grocery Manufacturing Association's chief science and regulatory affairs officer, said canned goods are "an affordable source of high-quality nutrition and we would hate for [consumers] to be scared away by one report when the vast majority of the regulatory agencies globally have assured its safety."
The Campbell Soup Co. told ABC News, "While the overwhelming weight of scientific evidence clearly supports the safety of BPA, Campbell is currently researching alternatives. To date, no satisfactory alternative has been identified for a broad range of products."
Nestle USA defended the levels of BPA in its Juicy Juice boxes, saying the levels are 430 times below federal guidelines. In addition, Nestle spokeswoman Pam Krebs said, "The can lining, which has a BPA component, helps protect the nutrient levels in the juice and helps maintain overall product quality."
Consumer concern has convinced top baby bottle manufacturers to dump BPA and this latest report adds to the worry.
"I'm kind of thinking about it, if I should buy these foods for my kid," said Veronica Miranda while shopping in Washington, D.C. "Because, you know, it's our kids were talking about here."
"People are exposed to minute levels, levels that are about a thousand times below safety standards set by government agencies around the world," said Steve Hentges of the American Chemistry Council.
Consumer's Union admits what it considered unsafe is 20,000 times lower than goverment standards, but it said those standards are based on decades old data.
"The FDA itself is reviewing what that safety limit is this month. It has been criticized by its own scientific board for being inadequate," Ragan said. "We don't think the safety limit is protective enough, and based on the hundreds of studies that have been done since the FDA set their safety limit, there is the majority of studies showing that there is harm from low dose esposures to BPA."
"If you can choose fresh food over cans it is better anyway and this is just one more reason to choose fresh," Ragan said.