The next time you are shopping at your local supermarket, pause for a moment in the canned-food aisle.

What you might not know is that inside a can of green beans or cream of mushroom soup, there is one ingredient not listed on the label - a dangerous chemical called bispehnol-A, or BPA.

BPA is a chemical used to harden plastics and to line tin cans to extend the shelf life of canned foods.

But in addition to ensuring that canned foods can sit on the supermarket shelf or in your pantry for long periods of time, BPA can also leach from the lining of the can and be absorbed into food and beverages.

In other words, every time you open up a can, you are most likely ingesting the chemical BPA.

A new study from the Food and Drug Administration found BPA had leached into more than 90 percent of canned foods tested. The study found that the chemical is so pervasive in canned foods that it is in more than 93 percent of Americans.

The powerful chemical industry will try to assure you that BPA is harmless.

It's not.

There are more than 200 scientific studies linking BPA to serious health problems, including brain and behavioral disorders, cancer, diabetes, heart disease, obesity, and early puberty. BPA is a known endocrine disruptor, which means it interferes with the way hormones work in the body by blocking their normal function.

I've introduced legislation to ban BPA from children's feeding

products, because children are the most vulnerable to the potentially harmful health effects of BPA. A simple first step is to take action to protect babies and children by taking this chemical out of baby bottles, sippy cups, infant formula cans, and baby food containers.

In light of this information, I've also stopped buying canned foods. I look for soups in glass jars or tomatoes in Tetra paks - the paper carton packaging that resembles oversized juice boxes. I try to look for dried or fresh fruit or buy what's local and seasonal.

Not every consumer has these options, which is why it is even more critical that we get this chemical out of cans.

For many Americans, canned food is the least expensive, most nutritious option for meals. And for many Americans right now, there is no option to buy BPA-free food.

Among canned foods, vegetables (especially green beans) have the highest levels of BPA. Ravioli, pasta with meatballs, and other canned meals also have high levels of BPA due to higher fat and sodium content, which encourages chemical leaching.

Some companies have started to use safety-tested, BPA-free alternatives in their products. Eden Foods sells BPA-free canned beans. Last year General Mills announced it would introduce a BPA-free metal can for their Muir Glen tomatoes. Heinz, Hain Celestial and ConAgra already use BPA-free can linings for certain products. Trader Joe's offers BPA-free cans for a number of its products.

This month, the Breast Cancer Fund is asking consumers who can make a choice or who do have alternative sources of nutrition to join them in their campaign to "kick the can" and stop eating canned foods for the month of July.

This effort will send a big message to canned food industry that we want BPA-free food and safer packaging to replace it.

The can manufacturers need to know that you are concerned for your health, and that you are taking action.

Until we know more about BPA, I firmly believe that we need to err on the side of caution and remove this potentially harmful substance from food products.

To join the Breast Cancer Fund or to learn more about "Kicking the Can" I hope you will consider taking a better look at the canned food aisle this July.

Dianne Feinstein represents California in the United States Senate.