DuPont Co. hid studies showing the risks of a Teflon-related chemical used to line candy wrappers, pizza boxes, microwave popcorn bags and hundreds of other food containers, according to internal company documents and a former employee.

The chemical Zonyl can rub off the liner and get into food. Once in a person's body, it can break down into perfluorooctanoic acid and its salts, known as PFOA, a related chemical used in the making of Teflon-coated cookware.

The Environmental Protection Agency has been trying to decide whether to classify PFOA as a "likely" human carcinogen. The Food and Drug Administration, in a letter released Wednesday evening by DuPont, said it was continuing to monitor the safety of PFOA chemicals in food.

The DuPont documents were made public Wednesday by the Environmental Working Group, a research and advocacy organization.

At the same time, a former DuPont chemical engineer, Glenn Evers, told reporters at a news conference at EWG's office that the company long suppressed its studies on the chemical.

"They are toxic," Evers said of the PFOA chemicals. "They get into human blood. And they are also in every one of you. Your loved ones, your fellow citizens."

From 1981 to 2002, Evers helped DuPont develop new products. He lost his job in 2002 in what DuPont described as a company restructuring.

Evers had a different view: "It is my belief DuPont pushed me out of the company" because he started raising concerns about the chemicals' safety.

Evers said he decided to talk publicly about the PFOA problem after filing a civil suit against DuPont this month in a Delaware court. Evers' aim is mainly to "set the record straight" about the chemical and his own career, said Herb Feuerhake, Evers' lawyer.

But Evers said he also hoped to influence the outcome of an EPA hearing later this month on whether DuPont had withheld from EPA the study on PFOA and possible birth defects. The company could be fined millions of dollars.

After EWG tracked down Evers — who had provided expert, unpaid testimony in two lawsuits against DuPont — the 47-year-old Delaware resident said he talked it over with his priest, who told him, "`You can't dance with the devil.'"

DuPont denied allegations that PFOA posed a health risk, saying the Food and Drug Administration had approved the products for consumers.

"These products are safe for consumer use," the company said in a statement. "FDA has approved these materials for consumer use since the late 1960s, and DuPont has always complied with all FDA regulations and standards regarding these products."

The company said Evers "had little if any direct involvement in PFOA issues while employed at DuPont. ... Evers expressed a wide range of personal opinions that are inaccurate, counter to FDA's findings, and which DuPont strongly disputes."

The environmental group on Wednesday gave the FDA and the EPA copies of DuPont-sponsored internal studies indicating higher dangers from Zonyl than the government knew, including its ability to migrate into the food.

One of the documents, a 1987 memo, cites laboratory tests showing the chemical came off paper coating and leached into foods at levels three times higher than the FDA limit set in 1967. Another document, a 1973 Dupont study in which rats and dogs were fed Zonyl for 90 days, said both types of animals had anemia and damage to their kidneys and livers; the dogs had higher cholesterol levels.

"What makes this worse is that DuPont knew at that time that Zonyl breakdown-products, such as PFOA, in food were very persistent in the environment and were contaminating human blood, including the fetal cord blood of babies born to DuPont female employees," EWG Senior Vice President Richard Wiles wrote to FDA and EPA officials.

Wiles asked the agencies to determine whether DuPont should be penalized for withholding the studies. Last year, based on another DuPont document that the environmental group obtained, EPA alleged the company had repeatedly failed over a 20-year period to submit required data about PFOA. The document referred to a study that suggested possible links between PFOA and birth defects in infants.

EPA spokeswoman Eryn Witcher said Wednesday the agency "has an extensive effort under way to determine the sources of PFOA, how the public is being exposed, and whether these exposures pose a potential health risk."

Evers' decision to go public with his concerns may have already had an impact.

In August, he told a Mississippi court that all three of DuPont's U.S. plants were releasing "massive amounts" of dioxin — a class of organic chemicals that EPA studies have shown pose a possible cancer risk in humans. In that case, an oyster fisherman who claimed dioxin from a DuPont plant caused his rare blood cancer was awarded $14 million in actual damages and his wife received $1.5 million.

He also testified last year in a West Virginia case in which DuPont agreed to a $107.6 million settlement of a class-action suit. Residents around a plant near Parkersburg, W.Va., had said that PFOA contaminated their drinking water supplies. DuPont also remains the target of another class-action suit over PFOA seeking $5 billion.