Congress is in favor of protecting employees from dangerous working conditions, right? Yet a new draft rule to protect employees from hazardous substances by requiring more rigorous scientific analysis by the Labor Department is facing opposition from leaders of the two congressional committees with jurisdiction.

Senate Health, Education, Labor, and Pensions Chairman Edward Kennedy of Massachusetts and House Education and Labor Chairman George Miller of California asked the Labor Department to withdraw a so-called “secret regulation” even before the two Democrats had seen its contents.

According to their July 23 letter to Labor Secretary Elaine Chao, “We are deeply disappointed that the Department of Labor is working to slip through a rule that may have a profound negative impact on the health and safety of American employees. It is equally disturbing, according to today’s Washington Post, that the Department is moving this proposal over the objections of career staff in the relevant health and safety agencies. “

An examination of the alleged draft proposal published by the Washington Post shows that the letter from Mr. Kennedy and Mr. Miller was premature and incorrect. The draft rule would set higher standards for assessing dangers to employees of substances in the workplace, increasing their protection.

The Labor Department would get more public feedback and use peer reviewed studies; provide more information and calculations in reports; and make industry-specific calculations. This would be more precise than current Labor Department procedures.

For instance, the Labor Department is in the process of regulating two substances, beryllium and silica. If the new rule were in place, workers would have access to all the scientific studies on these compounds, different industries would have sent in information on worker exposure, and the public would be able to see detailed comments from unions and businesses.

Instead, in June 2007, the federal District Court for New Jersey had to order the Department’s Occupational Safety and Health Administration to provide documents on toxic exposures of its own workplace inspectors, because it refused to do so. This followed a suit by University of Medicine and Dentistry of New Jersey Professor Adam Finkel, a former chief regulator and regional administrator at OSHA.

Although I served as chief economist of the Labor Department between 2003 and 2005, I did not work on this proposed rule. Between September 2007 and January 2008, however, the Hudson Institute, where I work now, was part of a team of outside economists under contract to the Labor Department to evaluate risk assessment procedures in federal agencies. So, I know a lot about the problem.

The new rule would follow the pattern of transparency in regulation adopted by Ms. Chao with union financial disclosure regulations. It would give the public and Congress more input into future decisions about how to regulate harmful substances.

Government officials would have to demonstrate, using peer-reviewed scientific studies, that substances were harmful. This helps employees by making sure that OSHA regulates real hazards and uses real science, not junk science and bogus risks.

When determining the consequences of exposure to potentially harmful substances, OSHA now estimates how long employees will be exposed. The proposed rule improves these estimates by requiring realistic estimates of time worked by employees who spend their entire lives in one industry. Now, the Labor Department assumes that employees work at the same job for 45 years, and work for 40 hours a week, 50 weeks a year.

This does not accord with reality. Employees tend to work fewer total years for one industry and have more vacation days. Yet, with overtime becoming increasingly common, they spend far more than 40 hours a week on the job. Workers may need more protection, because exposure to a carcinogen 55 hours a week for 10 years could potentially be more harmful than exposure for 40 hours a week for 45 years.

Critics complain that these requirements for sound science are too sweeping and may prevent OHSA from regulating hazardous substances.

In particular, some OSHA career staff have opposed the proposal, taking their case to the Washington Post as frequently happens in Washington. A rule based on sound science would diminish the power and discretion of government staffers, because the burden of proof would be on the scientific evidence rather than on their decisions.

Yet disclosure of competing interpretations and gaps in the data are elements of intellectual honesty.

The proposed rule would give the public — including unions and employers — an earlier voice in the regulatory process. An Advance Notice of Proposed Rulemaking would be required for every health rule, and scientific studies on the potential hazards would have to be posted by the Labor Department within seven days of a rulemaking announcement.

The congressional Democratic critics are probably unaware that the Labor Department is following the recommendations of a 1997 report by President Clinton’s Commission on Risk Assessment and Risk Management.

The mystery is not why the Labor Department moves so fast, but why Congress wants it to move even more slowly.

Ms. Furchtgott-Roth, former chief economist at the U.S. Department of Labor, is a senior fellow at the Hudson Institute.