In one of the boldest moves toward eliminating toxins from products consumers use everyday, Wal-Mart Stores on Thursday notified its suppliers they will have to reformulate soaps, makeup and household cleaners as the world's largest retailer begins to shed harmful chemicals from store shelves.

Wal-Mart's new policy, announced in September but outlined in detail for the first time Thursday, signals the start of a pivot in the personal care products industry as the retailer demands higher standards of safety -- oversight that the federal government doesn't have.

Health and environmental advocates expect possibly tens of thousands of products will be reformulated to remove harmful ingredients and meet Wal-Mart's new standards. And with Wal-Mart as their biggest customer, most manufacturers will choose to make their products safer rather than get kicked out of the big-box stores, advocates say.

"When big retailers like Wal-Mart choose to offer safer products, that is a really fast way to effect change," said Arlene Blum, executive director of the Green Science Policy Institute and a chemistry expert at UC Berkeley. "This will help shift the marketplace is the right direction and potentially have a huge impact on our health."

The initiative is one of the most sweeping efforts to reduce consumers' exposure to toxins, and other retailers are expected to follow Wal-Mart's lead. Target already announced a similar policy last October that encourages manufacturers to remove dangerous chemicals from products.

"In several years we may be able to see a decline in the usage of these high priority chemicals," said Sarah Vogel, director of health programs at the Environmental Defense Fund, a nonprofit that has worked with Wal-Mart on the new policy.

Wal-Mart has identified certain chemicals considered dangerous -- because they cause cancer, reproductive damage or other health or environmental harm -- and wants them removed from beauty products, baby and household supplies and pet products. Manufacturers must disclose the ingredients they use by January 2015, and either reduce or eliminate harmful ingredients in their products within a couple years to comply with the new standards.

"This is going to change the standard nationwide," said Margie Kelly, spokeswoman for the Campaign for Safe Cosmetics, a San Francisco-based nonprofit that advocates for safer cosmetics. "We are fairly certain that Procter & Gamble is not going to make one set of products for Wal-Mart and one set for everyone else."

Wal-Mart is working with suppliers to find safe substitute ingredients, and says it will track its suppliers' progress and update customers by January 2016.

"This is a big step in the right direction," said Harold Zeliger, a chemist and nationally recognized expert on toxins in cosmetics. The chemicals Wal-Mart has identified "are indeed among the most toxic that consumers are regularly exposed to."

Wal-Mart used guidelines from the EPA, European Union, U.S. National Toxicology Program, California Proposition 65 and other state regulations to create a list of chemicals it wants suppliers to stop using. But Wal-Mart is starting with a list of 10 chemicals pegged for elimination -- only it won't release that list to the public. Some advocates panned the retailer for concealing the chemicals from consumers buying the very products that contain them.

"This is being driven by consumers' need to know. Ultimately, there has to be more transparency for consumers to understand what chemicals are dangerous," Kelly said.

The retailer declined to answer questions about why the public could not know which chemicals it was working to eliminate, saying only: "We're excited to offer a road map that will help suppliers of consumables products to transparently disclose product ingredients and transition to greener substitutes for priority chemicals."

The American Chemistry Council, the industry trade group for U.S. chemical companies, is working with Wal-Mart to advise the retailer why beauty and household products need certain chemicals to last longer in a medicine cabinet or retain a fragrance.

"We already know a great deal about specific chemicals and how they interact with the body," the council said in a written statement. "Efforts to assess a product's safety should include considerations of product use, actual consumer exposure to the chemical, and how and why the chemical is used in the product."

Contact Heather Somerville at 510-208-6413. Follow her at Twitter.com/heathersomervil.

new Wal-Mart chemicals policy
What chemicals: 10 "high-priority" chemicals to be removed or reduced in products, and dozens more "priority" chemicals.
What products: Health and beauty, pet supplies, baby care, household cleaners, cosmetics, skin care, laundry, paper goods, bags and home care
What stores: All U.S. Walmart and Sam's Club locations
Timeline: By January 2015, suppliers must disclose product ingredients in a private online database managed by a third party. By January 2016, Wal-Mart will update the public on supplier compliance. By 2018, chemicals will be disclosed on product packaging. Last month, Wal-Mart began adding labels to cleaning products that meet standards set by the federal EPA's Design for the Environment program