You won't find it on the list of ingredients, but many cans of Campbell's soup come with a bit of bisphenol-A, which helps keep can linings from leaking. The widespread use of chemical, also known as BPA, has raised concerns from parent groups, cancer groups and the Food and Drug Administration. This week, the Campbell Soup Co. said it will stop using BPA in its cans.

BPA-free advocates hailed the news as a big step for the canned-foods industry. The world's largest soup maker had been a holdout on this issue: Brands such as Eden Foods, Muir Glen, Trader Joe's, Heinz and ConAgra already have committed to phasing out the chemical.

But it could take some time to dispense with BPA  for good. While BPA-free liners are available, they cost more and don't work well for some foods, like tomatoes, that have higher acidity levels. Campbell's didn't say when it plans to stop using BPA. "We have already started using packaging lined with a BPA alternative in some of our soups, and we are working to phase out the use of BPA in can linings in the rest of our canned products," the company says in its updated corporate sustainability report.

While the food and chemical industries – and, until 2010, the FDA – maintain that BPA is safe for humans, some studies have linked it to a variety of health ailments, such as cancer, obesity, heart disease and diabetes, in animals. The chemical mimics the hormone estrogen.

The FDA is expected to make a decision about whether to ban or regulate the chemical at the end of this month. Meanwhile, France in February upheld a ban on BPA in packaged foods, and California last year banned the use of BPA (above 0.1 part per billion) in baby bottles and infant cups.

The move comes less than a week after the Campbell Soup Co. won one of the Environmental Protection Agency's inaugural Climate Leadership Awards.

You can read more about Campbell's moves toward sustainability in these GreenBiz interviews:

• Campbell's former CEO, Doug Conant, and current CEO, Denise Morrison, share their thoughts on sustainability with GreenBiz columnist Heather King.  
• Dave Stangis, the company's vice president of corporate social responsibility, discusses "the evolution of sustainability" with "Nature of Business" radio host Crissy Coughlin.
• Stangis talks about tips for making sustainability everyone's job at the State of Green Business Forum.

Aside from criticism over BPA, Campbell      's also has taken fire for using genetically modified ingredients.

Photo courtesy of profzucker via a Flickr Creative Commons license.