Europe this month rolled out new restrictions on makers of chemicals linked to cancer and other health problems, changes that are forcing U.S. industries to find new ways to produce a wide range of everyday products. The new laws in the European Union require companies to demonstrate that a chemical is safe before it enters commerce -- the opposite of policies in the United States, where regulators must prove that a chemical is harmful before it can be restricted or removed from the market. The changes come at a time when consumers are increasingly worried about the long-term consequences of chemical exposure and are agitating for more aggressive regulation. The European Union's tough stance on chemical regulation is the latest area in which the Europeans are reshaping business practices with demands that American companies either comply or lose access to a market of 27 countries and nearly 500 million people. From its crackdown on antitrust practices in the computer industry to its rigorous protection of consumer privacy, the European Union has adopted a regulatory philosophy that emphasizes the consumer. There's a strong sense in Europe and the world at large that America is letting the market have a free ride," said Sheila Jasanoff, professor of science and technology studies at Harvard University's John F. Kennedy School of Government. "The Europeans believe . . . that being a good global citizen in an era of sustainability means you don't just charge ahead and destroy the planet without concern for what you're doing."