Wal-Mart Stores Inc. on Thursday announced a new ban on some chemicals found in cosmetics, household cleaners and beauty products, marking one of the most significant victories yet for advocacy groups that have led the national battle for safer cosmetics for more than a decade.

With its new policy, unveiled at the company's annual Global Sustainability Milestone Meeting, Wal-Mart becomes the first major retailer to begin phasing out some harmful ingredients found in everyday beauty and personal care products such as lipstick and shampoo.

The policy targets about 10 potentially hazardous chemicals for reduction or elimination from consumable products sold in Wal-Mart. Beginning in January, Wal-Mart will begin monitoring these products for levels of risky chemicals, and by January 2015, Wal-Mart will require that suppliers post online a list of ingredients for items they sell at the company's stores. By 2016, Wal-Mart will begin to report publicly on suppliers' progress in meeting these new chemical requirements. Suppliers that don't remove or reduce potentially harmful chemicals from their products will be required to label packages with a warning.

The retailer did not say which chemicals would be targeted but said the policy, which has been in the works for more than a year, would continue to evolve. Wal-Mart is collaborating with the U.S. Environmental Protection Agency and the Environmental Defense Fund, a national nonprofit advocacy group with offices in San Francisco and Sacramento.

"It's been a decadelong process. It's been step by step," said Stacy Malkan, co-founder of the Campaign for Safe Cosmetics, the leading advocacy coalition for eliminating potentially cancer-causing chemicals from cosmetics.