Undue partisanship has become a scourge in Congress, but there was none evident at a Wednesday hearing on a singularly scary issue: safety lapses at federal laboratories handling deadly specimens of anthrax and smallpox.

Members of a House oversight committee clearly recognized that there's no more room for error. The Centers for Disease Control must get a grip on potential hazards to public health and safety in its own laboratories.

Those include recently reported incidents of mishandling live anthrax bacteria and bird flu virus, and the discovery of forgotten vials of viable smallpox virus in a cold storage area at a former National Institutes of Health site in Maryland.

CDC Director Thomas Frieden told the oversight committee that he personally has taken charge of the situation, closing two labs where errors occurred, and naming a senior scientist to lead a safety initiative within the agency.

"With the recent incidents, we recognize a pattern at CDC where we need to greatly improve the culture of safety," Dr. Frieden said.

No kidding.

There is enough anxiety about potential terror uses of biohazards without the fear of an accidental release by federal scientists tasked with helping to ensure the nation's safety from deadly biological material.

But Rep. Diana DeGette, D-Colo., noted that there have been repeated warnings over the years about mishandling of material used in research. And there have been repeated assurances that safety measures would be improved. Her observations were reiterated by other committee members.

"Why should we believe this time things will be different?" asked Rep. Fred Upton, R-Mich.

Shortcomings have been repeatedly cited in reports by the Government Accountability Office and in news investigations.

USA Today, for example, reported continuing problems in 2007-08 with an airflow system designed to ensure safety in a CDC lab in Atlanta. Duct tape was used to secure a door in an area where research was being done on Q fever, a bacterially borne disease.

On Tuesday, the newspaper cited reports obtained under the Freedom of Information Act showing violations at a variety of labs: six federal, 11 university, and eight operated by state, local or private agencies.

Those findings should encourage a broader solution than the limited measures announced by Dr. Frieden. The GAO has recommended, for example, strict limits on the number of labs allowed to handle the dangerous material and strong federal oversight for all of those labs.

The research done in those labs is essential to forestall the threat from killer viruses and bacteria.

It would be doubly tragic if lapses in safety procedure served to create an unwitting avenue to public exposure.