The report was greeted by some environmental groups as confirmation of their warnings, while chemical makers latched on to the report's preliminary nature and its authors' warning against drawing overly worrisome conclusions.
The federal National Toxicology Program said Tuesday that experiments on rats found precancerous tumors, urinary tract problems and early puberty when the animals were fed or injected with low doses of the plastics chemical bisphenol A.
While such animal studies provide only "limited evidence" of bisphenol's developmental risks, the group's draft report stresses the possible effects on humans "cannot be dismissed." The group comprises scientists from the U.S. Centers for Disease Control and Prevention, the U.S. Food and Drug Administration and the U.S. Institutes of Health.
More than 90 percent of Americans are exposed to trace amounts of bisphenol, according to the CDC. The chemical leaches out of water bottles, the lining of cans and other items made with it.
The American Chemistry Council, which represents manufacturers, said the report "affirms that there are no serious or high level concerns for adverse effects of bisphenol on human reproduction and development." Among the manufacturers of bisphenol are Dow Chemical Co. and Germany-based BASF Group.
The group said it supports additional research to determine whether adverse effects seen in animals "are of any significance to human health."
Environmentalists, meanwhile, hailed the report as the first step toward reassessing a chemical they believe could contribute to cancer and other health problems.
"We're hoping this decision will force FDA to recognize the toxicity of this chemical and make manufacturers set a safety standard that's protective of the most vulnerable populations," said Dr. Anila Jacob of the Environmental Working Group.
The toxicology group's findings echo those of researchers assembled by the National Institutes of Health, who in August recommended more research on bisphenol in humans.
The FDA said in November there is "no reason at this time to ban or otherwise restrict its use." The agency on Tuesday did not immediately have any comment about the new report.
Growing misgivings about the chemical have pushed many consumers toward glass alternatives, and triggered investigations by state and federal lawmakers.
Democratic Rep. John Dingell urged FDA on Tuesday to reconsider the safety of bisphenol, saying the toxicology report's findings "fly in the face of the FDA's determination."
Dingell, who chairs the Energy and Commerce Committee in the House of Representatives, issued letters this year to seven companies that make baby formulations questioning whether they use bisphenol in the lining of their cans and bottles.
The companies included Hain Celestial Group, Nestle USA and Abbott Laboratories.
A spokeswoman for the International Formula Council, which represents baby food makers, said Tuesday, "The overwhelming scientific evidence supports the safety" of bisphenol, adding that no foreign governments have restricted or banned its use.
The National Toxicology Program will take public comments on its initial report through May. A final version will be issued this summer.
State lawmakers in New Jersey passed a bill this month that would ban the sale of all products containing bisphenol in that state.
Canada's health agency also is examining health risks of bisphenol and is expected to issue its findings in coming days.
However, three of Canada's major retailers said Tuesday they were pulling bottles that contain the controversial chemical, in anticipation of Health Canada labeling it a dangerous substance.
The Forzani Group, Canada's largest sporting goods retailer, and Hudson's Bay Company, which includes Bay and Zellers stores, announced they're removing products containing bisephenol, including water and baby bottles, from their shelves.
Several other Canadian retails had already moved to take the products out of stock or to offer refunds on items already sold.