Beth Knoll 7:02 p.m. CDT September 9, 2014

When it comes to the widely used chemical bisphenol A, the question is not whether it is harmful. The debate focuses on how much of the chemical is safe for human consumption.

Caroline Cox, research director for the Center for Environmental Health in Oakland, Calif., said most scientists believe BPA is a toxic chemical, used in a variety of plastics as well as in the coating inside food cans. According to some studies, the chemical has been shown to disrupt hormone levels in the body, which could contribute to health problems such as cancer.

“The big picture is that hormones are so central to how our bodies work, that when you mess with them, you can have long-lasting effects,” said Cox, who noted that most people have BPA inside their bodies due to its common usage. “I think the research has shown a wide array of health effects that are associated to exposure with BPA.”

Despite the “incredible” amount of research that Cox said scientists have conducted on BPA in the past decade, Mike Hayes, professor of chemistry at Union University, said researchers have little agreement over the results concerning the safety of the chemical.

According to Hayes, BPA has been determined to be relatively safe. While some companies have removed the chemical from certain products for babies or young children, he noted that marketers abandoned the chemical due to public opinion rather than any danger the chemical posed.

“Like almost anything … it can be harmful if you get too much of it,” Hayes said. “The question is, how much is too much?”

Organizations such as the Food and Drug Administration continue to support the use of BPA in food packaging products, with FDA press officer Lauren Sucher stating that the FDA’s “rigorous” review of scientific evidence supports the use of the chemical in food containers and packaging.

Sucher noted the FDA requires that food packaging must be deemed as safe before being marketed, as part of the food additive provisions of the Federal Food, Drug and Cosmetic Act.

“Under U.S. law, manufacturers are responsible for assuring the safety of their food packaging,” Sucher reported from FDA technical experts. “FDA’s current perspective is that BPA is safe when used consistent with our regulations. Based on FDA’s ongoing safety review of scientific evidence, the available information continues to support the safety of BPA for the currently approved uses in food containers and packaging.”

When it comes to safe levels of BPA, the FDA website referred to a study in which pregnant rats were fed BPA in amounts 100 to 1,000 times the normal amount consumed by humans. The rat fetuses shown to remain untouched by the BPA within eight hours of the study.

Other studies provide opposing results, Cox said, particularly more recent studies that show BPA is harmful even in minute amounts when given to pregnant monkeys.

Cox added that some items advertised as BPA-free, such as color-changing baby bottles or sippy cups, contain BPA substitutes that the Center for Environmental Health has found to release levels of synthetic hormones that some scientists believe could be harmful to humans.

“In fact, some of (the sippy cups) had more estrogenic activity than actually a cup made of BPA,” Cox said. “It’s worrisome, and it also really shows the problems with not knowing much about the health effects of the chemicals in the products that we use.”

While Sucher said that food manufacturers must report the substances in food packaging, Cox said that companies rarely tell consumers which chemicals or substances — such as BPA or similar chemicals — are used in their products.

Even if companies are up front about the chemicals used in food packaging, Cox added that little information exists on the potential health problems from the new chemicals used to replace BPA.

“It’s a muddled mess at the moment,” Hayes said. “‘No one really knows’ is the bottom-line answer.”

Hayes said that new chemical substitutions are being considered to replace BPA, including a substance made out of wood. But introducing new chemicals on the market can be difficult, he said, making BPA the safer option at the moment.

But for Cox, it’s better to be safe than filled with chemicals with a questionable safety record.

“Here at the Center for Environmental Health, we like to take a precautionary approach,” said Cox, who suggested that people use items such as glass or stainless steel water bottles, rather than their plastic counterparts. “A lot of times, it takes time for science to figure out what the problems are.”