The Centers for Disease Control and Prevention Thursday said it was allowing one of its high-security labs to resume transfer of biological materials after authorities imposed a ban on all such shipments in response to a series of incidents involving the mishandling of pathogens at CDC labs.

The CDC’s clinical tuberculosis lab has resumed transfer of inactivated tuberculosis bacteria to lower-level CDC labs for genetic analysis, the CDC said in a statement. The ban remains in place for several dozen other CDC labs until they pass a safety review, spokesman Tom Skinner said.

The agency also named an 11-member external laboratory safety group to advise CDC Director Tom Frieden and the CDC’s new director of lab safety, Mike Bell. It will be asked to suggest safety improvements for CDC’s laboratories, which conduct some of the world’s most sophisticated research into infectious diseases.

The ban and high-level safety groups are among the “sweeping measures” Frieden vowed to take to improve the culture of safety at the CDC after lapses over the past decade, including last month’s anthrax scare and the mistaken shipment of other dangerous pathogens, including botulism bacteria and samples of the virulent H5N1 influenza virus. The head of the bioterrorism lab that potentially exposed scores of employees to live anthrax bacteria resigned abruptly this week.

A scientist in the bioterrorism lab failed to follow adequate protection procedures to inactivate anthrax samples being sent from that lab in Atlanta to several other CDC labs. Workers at the other labs, believing the samples had been inactivated, were not wearing adequate personal protective equipment while handling the material.

CDC officials lifted the ban on the clinical TB lab after an internal working group reviewed and approved the lab’s detailed safety procedures for inactivating tuberculosis bacteria. The killed bacteria is sent to lower-level CDC labs for genetic analysis that allows clinicians to know within days whether their patients have multidrug-resistant strains of tuberculosis and which drugs will be most effective.

An internal working group is reviewing safety procedures lab by lab because different labs work with different pathogens and safeguards must be tailored to each individual lab, officials said.

The new external lab safety group is scheduled to meet for the first time in early August.

Its members are chair Joseph Kanabrocki, assistant dean for biosafety and associate professor of microbiology at the University of Chicago; co-chair Kenneth Berns, a physician and professor emeritus specializing in molecular genetics at the University of Florida; Debra Hunt, director of biological safety at Duke University; Thomas Inglesby, head of the University of Pittsburgh Medical Center for Health Security; Patricia Olinger, director of Emory University’s environmental health and safety office; Michael Pentella, director of the laboratory sciences bureau at Hinton State Laboratory Institute; David Relman, chief of infectious diseases at the VA Palo Alto; Heather Sheeley, who heads corporate biosafety for Public Health England; Fred Sparling, director of the Southeast Regional Center for Excellence for Emerging Infections and Biodefense, University of North Carolina-Chapel Hill; Jill Taylor, director of the public health laboratory at New York state’s health department; and Domenica Zimmerman, biosafety officer at the University of Texas Medical Branch.