New chemicals must prove they are safe before they can be sold

US environmental regulators just issued new rules for certain chemicals. Companies must now get approval before they can make or import these chemicals for new uses.

For decades, many chemicals could be sold without much review, and regulators could only act after problems appeared. This change means companies must now show a chemical is safe for its intended use before it hits the market. This shifts the burden of proof from the public to the manufacturer.