What now for bisphenol A?

On Friday, the U.S. Food and Drug Administration denied a petition asking it to ban the controversial chemical, bisphenol A, from food and food packaging.

But it said its studies of the chemical, also known as BPA, are not complete. So, in other words, stay tuned.

How this ultimately plays out is anyone's guess.

In a story in Friday morning's paper, I explained the issue.  It's a complicated legal history, but in its simplest form, an environmental group, the Natural Resources Defense Council, filed a petition askiong the FDA to ban the sbustance.  It's view was that while the science was still sorting things out, there was enough evidence to warrant the ban. What's important here, as a legal expert for the group pointed out, is that the FDA has to prove that the chemical is safe before it can allow its use. If the FDA doesn't know or isn't sure, it can't allow the chemical's use.

BPA is a substance that hardens plastics.  It was used in plastic baby bottles, which seemed a good substitute for glass because they didn't break. But after scientists realized it could leach into the contents of the bottle, consumers pressured manufacturers to remove it. Many did.

It also is widely used as a protective lining in food cans.  Now that some studies have shown that BPA leaches into the food, consumer pressure is once again forcing companies to responts. As Friday's story pointed out, Campbell's Soup in Camden has engaged in a multi-year effort to phase out the chemical.  The company maintains that BPA is safe, but that consumer trust is paramount.

BPA is an endocrine disruptor, and various studies have pointed to health effects, including disruption of the hormone system and cancer.

The FDA was facing a March 31 court-ordered deadline to respond to the petition, and later on Friday the agency announced a decision: denied.

This story by Matthew Perrone of the Associated Press explains the FDA's reasoning. Officials said the NRDC did not present compelling evidence to justify a ban.

That sounds like the opposite of what the NRDC legal expert said was necessary. The chemical chouldn't be allowed until officials are sure, the NRDC said.

Either way, the agency said its research into the chemical continues. Indeed, $30 million in government-funded studies are under way.

Sarah Janssen, senior scientist in the public health program at the NRDC, responded that "BPA is a toxic chemical that has no place in our food supply. We believe FDA made the wrong call.

"The agency has failed to protect our health and safety ­ - in the face of scientific studies that continue to raise disturbing questions about the long-term effects of BPA exposures, especially in fetuses, babies and young children," she said. "The FDA is out-of-step with scientific and medical research. This illustrates the need for a major overhaul of how the government protects us against dangerous chemicals."

Today, Tom Philpott at Mother Jones looks further into why the agency reached the decision it did. He cites a Bloomberg News story that says the BPA worldwide market is valued at $8 billion. Although Philadelphia-based Sunoco makes BPA at an Ohio plant, one of the two biggest players worldwide is US-based Dow.

Philpott goes into more detail about the studies, and makes what is often a grueling recitation readable. He includes plenty of links, so you can delve to your heart's content.

He concludes: "The FDA's scientists may truly believe that it's prudent public health policy to preserve a status quo in which Americans, including children and pregnant women, continue consuming BPA in everyday foods. Then again, it's an election year, and as this blockbuster New York Times story demonstrates, the Obama White House has not been shy about pushing the agency around for political purposes. And the companies that make BPA, as well as the major food and can-making companies that have come to rely on it, are no political lightweights."