The new rules, set to go into effect over the span of a few years, will require manufacturers to eliminate roughly 10 “high-priority” chemicals from their beauty products and to disclose all chemicals used in synthetic fragrances, which often contain dozens of potentially harmful chemicals that are protected under federal law as “trade secrets” and thus aren’t legally required to be listed on product labels. More from Prevention: Phthalates Increase Diabetes Risk 30%  Also part of the announcement was a requirement that all household cleaners sold under the retailer’s Great Value private label meet the Environmental Protection Agency’s (EPA’s) Design for the Environment program standards. “The objective of this policy is to help ensure that household cleaning, personal care, beauty, and cosmetic products sold by Walmart will minimize hazards to people or the environment,” the company said in a statement. The Good & The Bad While the company’s announcement was long on ambition, it was short on details. Walmart isn’t releasing the list of chemicals being targeted, says its Senior Vice President of Sustainability, Andrea Thomas, in order to prevent “undue concern” among suppliers and customers. But she says that the list was developed with input from suppliers, academics, nonprofits, and the EPA. The chemicals were chosen based on known health hazards associated with them and their prevalence as an ingredient in products, says Katie Ware, a spokesperson for the Environmental Defense Fund (EDF), a nonprofit that helped Walmart develop its policy. More from Prevention: Your Sofa Is Messing With Your Hormones  Furthermore, this process could take a few years before shoppers start to see the benefits. Though companies are being asked to remove these chemicals—and the company will begin “monitoring progress” in 2014—it seems that companies won’t have to fully comply with the new policy until 2018. At that point, products that contain any of the designated 10 chemicals will have to disclose those on package labels. Still, public health advocates lauded the decision. “They’re very much recognizing that consumer demand for safer products has grown significantly,” says Stacy Malkan, cofounder of the Campaign for Safe Cosmetics and author of Not Just a Pretty Face: The Ugly Side of the Beauty Industry. She also called it a “loud-and-clear signal to companies that people don’t want to buy products made with toxic chemicals.” And because of the company’s enormous buying clout, its suppliers will likely change formulations for their products, regardless of where they’re sold. Few manufacturers will want to make one set of products specifically for Walmart and another for everyone else. Safer Chemicals on the Horizon It also appears that Walmart’s suppliers knew the shift was coming. Days before the announcement, Proctor & Gamble announced that it would be removing phthalates and triclosan from all its products; phthalates are hormone-disrupting chemicals linked to lower IQs, reproductive problems, and even asthma that are frequently used in synthetic fragrances, and triclosan is an antibacterial chemical linked to reproductive problems and suspected of contributing to the problem of antibiotic resistance. More from Prevention: How To Avoid Triclosan  Similarly, in 2012, SC Johnson, maker of Johnson’s Baby Shampoo, among other popular family products, became the first major company to remove those same chemicals, along with parabens, which are hormone-disrupting preservatives, and dioxane and formaldehyde, two carcinogenic contaminants in many personal care products. To avoid an approach resembling chemical-safety “whack-a-mole,” in which companies simply replace one toxic chemical with another, Walmart is requiring its suppliers to use a tool called GreenWERCS, developed by EDF, Clean Production Action, and other public health groups, to ensure that the replacements comply with established “green chemistry” requirements. “The fact that Walmart is using this tool is a critical first step toward safer products,” says Sarah Vogel, director of the EDF’s Environmental Health program. “This is better than anyone else out there.” More from Prevention: The Health Risks Of Popular Beauty Treatments