The law passed by the US Congress in 1996 allowing it to overthrow expensive government regulations was supposed to ensure that any such rules were underpinned by “sound science”.

But last week Congress was being accused of ignoring such science, when both houses used the law to throw out rules governing ergonomics in the workplace. Developed by the Occupational Safety and Health Administration (OSHA), the rules were aimed at reducing repetitive-motion injuries by requiring employers to apply the latest ergonomics research.

Supporters of the OSHA regulations claimed that in repealing the rules, Congress was brazenly disregarding the scientific consensus reached in a report on ergonomics, which was published in January by the National Academy of Sciences (NAS).

House minority leader Richard Gephardt (Democrat, Missouri) thinks that the message in the NAS report is clear. “This is a critical issue affecting hundreds of thousands of workers every year,” he told the Congress, “and government needs to act in the name of their safety.”

The OSHA rules had been under development for a decade before they became effective on 16 January this year. They called for workers to be educated about the dangers of repetitive-motion tasks such as heavy lifting, operating vibrating equipment and typing. Under certain conditions, they also required employers to alter job specifications so that the tasks fell within established guidelines for injury prevention.

Many businesses and Republicans protested against the rules, saying that they could cost over $100 billion to implement. The OSHA estimated costs at $4.5 billion, but claimed that the rules would save companies over $9 billion through increased productivity.

The Congressionally mandated NAS study, “Musculoskeletal Disorders and the Workplace: Low Back and Upper Extremities”, did not explicitly assess the OSHA rules. But it concluded that repetitive-motion tasks significantly increase risks for certain injuries, and that proper intervention can reduce such risks.

“The whole action of repealing really shows a disregard for the science,” says Jonathan Stivers, a spokesman for Representative Nancy Pelosi (Democrat, California), a supporter of the rules. The NAS report “clearly justifies the need” for the new rules, he adds.

Republicans and the handful of Democrats who defeated the rules say that they agree ergonomic problems should be dealt with, but that the rules were poorly designed. “They were just too far-reaching, and were going to be a huge burden on business and industry and cause a lot more problems than they would correct,” says Dan Lara, a spokesman for the House Committee on Education and the Workforce.

“My sense of what's happening at the moment is that the [NAS] report is being largely put aside and other agendas are being pursued,” says Jeremiah Barondess, president of the New York Academy of Medicine and chair of the panel that produced the NAS report. “The science is there. The science is clear. You can like it or you can not like it, but that's what it is.”