Californiaβs Scary Product Warning Labels Might Be Working, Study Says NYT > Science By:Hiroko Tabuchi 13 February 2025 at 09:52 Products must state if they contain chemicals tied to cancer or other risks. As a result, manufacturers have pulled back from using the chemicals, researchers found. Β© Robert K. Chin/AlamyCaliforniaβs right-to-know law requires companies to warn of certain chemicals in their products.