Obama administration officials reject the criticism, saying that the benefits associated with the dozens of major rules adopted between President Obama’s inauguration and the end of 2009 outweigh the costs by an estimated $3.1 billion, a savings they assert is greater than that attributed to new regulations in the first years of the Clinton and Bush administrations.

They arrived at that figure by factoring in upfront costs — like the price of stronger brake systems being mandated in new tractor-trailers — with the estimated long-term savings — like reduced property damage and an estimated 227 fewer highway deaths each year.

“I don’t want to put anyone out of business,” said Inez Tenenbaum, chairwoman of the Consumer Product Safety Commission, who was appointed by Mr. Obama. “But if anything will help the marketplace, it is to make sure that people have confidence in the products that they buy.”

The Environmental Protection Agency is perhaps the most aggressive advocate of the new regulatory philosophy in Washington. It has moved quickly to reverse or strengthen Bush administration policies on power plant pollution, lead paint and toxic chemical discharges.

Last month, along with the Transportation Department, the agency mandated that automakers significantly cut greenhouse-gas emissions while increasing fuel economy standards, an issue the Bush administration had put on hold, citing the industry’s weakened financial condition. The car companies pronounced themselves happy with the result because it eliminated the possibility of even stricter regulation by California and about a dozen other states.

The agency’s administrator, Lisa P. Jackson, has made clear that she would prefer to have Congress tackle climate change through broad legislation in what would be one of the largest regulatory actions in American history. But if Congress fails to pass a law, she has already started the process of mandating standards on her own.

Image Toys from China were inspected in California by Stephen Gardner of the Consumer Product Safety Commission. Credit... Ann Johansson for The New York Times

The shift is also evident at major agencies charged with policing worker safety, health and consumer products. Many of the rules those agencies have adopted or are now pushing to impose — including a requirement that farmers refrigerate eggs and kill rodents to combat salmonella contamination on eggshells, which sickens 79,000 people a year — languished during previous administrations.