In another example of how Walmart can use its bulk to force widespread changes, the world's largest retailer has banned the use of a class of flame retardants in the products it stocks.

The company quietly banned polybrominated diphenyl ethers, or PBDEs, from some products a few years ago and recently notified suppliers it would begin testing products starting June 1 to ensure the chemical isn't being used, The Washington Post reported.

The ban affects hundreds of products on Walmart's shelves since PDBEs have been used in furniture, electronics, sporting goods, toys and more. Connected to brain development issues, reproductive problems and other ailments, PBDEs leach out of products and have been found in people in increasing levels in the last two decades, the Post reported.

Spokesman Lorenzo Lopez said Wal-Mart was motivated to act after a handful of states began banning PBDEs....

About a dozen states have banned two of the three types of PBDEs used in consumer goods, known as "octa" and "penta." Four states have also banned the third form, known as "deca," which is the most prevalent.

In addition to Walmart's ban, companies in the U.S. that make PBDEs have stopped or plan to stop making them by 2012.

The case of PBDEs has many similarities to what has been happening with bisphenol A (BPA), another chemical found in numerous products that has been connected to myriad health problems. Just as with PBDEs, some companies are removing BPA from products, and some states are passing partial or full bans on the chemical, although the federal government has not yet made any such move.

Chemicals policy in the United States puts a high burden of proof on the government to show that a chemical is dangerous enough to be restricted. Case in point: Asbestos is still legal here, while being banned in in about 60 countries, including Japan and all of the European Union. While some will continue to push forth bills that attempt to overhaul the federal chemicals system, more companies are likely to be taking closer looks at the materials they buy, use and move around, and even more will be affected by those that set new rules for themselves.

"This will have both direct and indirect ripple effects," Richard Denison, senior scientist at the Environmental Defense Fund, told the Post. "The companies producing for Wal-Mart are not going to make a special line for them and another line with those chemicals for everyone else. And this is going to make it easier for other retailers to follow suit."

_{Walmart store - CC license by oswaldo (Flickr)}