A federal judge is ordering the Food and Drug Administration to begin reviewing the health effects of e-cigarettes.
The ruling handed down Wednesday says the agency abdicated its legal duty when it postponed reviewing all U.S. vaping products by several years.
The American Academy of Pediatrics, Campaign for Tobacco-Free Kids and other groups filed the federal lawsuit in Maryland last year. The groups say the lack of FDA oversight has led to an explosion in underage vaping by teenagers, threatening to hook a generation of Americans on nicotine.
The FDA gained authority to regulate e-cigarettes in 2016, but it has allowed thousands of products to remain on the market without formal rules or safety standards.
The agency has said government and industry need more time to prepare for regulation.