Independent experts downplay safety concerns at CDC lab

An airflow malfunction at a Biosafety Level-3 laboratory in Atlanta has raised concerns about safety at the U.S. Centers for Disease Control, but independent experts said that there appears to have been little or no threat to public health.

Regardless, recently released reports about safety and security conditions at the CDC lab caught the attention of a congressional committee, which launched an investigation into biosafety procedures at the nation's premier public health organization, according to CIDRAP News.

Biosafety experts Dr. Joseph Kanabrocki and Dr. John Keene worry that that news coverage of the situation has left the public with the impression that the CDC facility poses a biohazard threat.

Kanabrocki is an assistant dean of biosafety and associate professor of microbiology at the University of Chicago. Keene is managing partner at Global Biohazard Technologies and president of Biohaztec Associates. He is a past president of the American Biological Safety Association.

Kanabrocki said that BSL-3 labs like the one at the CDC always have multiple redundant safety systems in place to protect employees and the public. Pathogens are always handled inside primary containment cabinets. He stressed that the airflow reversal would have only been a concern had it occurred in conjunction with a major spill and a malfunction in backup systems.

"I think the first thing to get across to the public and Congress is that containment does not mean contaminated," Keene said, CIDRAP News reports.

Keene said BSL-3 and BSL-4 labs are not considered to be contaminated unless a massive spill occurs outside of the primary containment device, which did not happen.

Kanabrocki said the ventilation systems in labs are complex devices, and even systems designed to maintain negative pressure in the event of a power outage or fan failure can take a few seconds to reverse the airflow. He stressed that transient pressure changes are not dangerous.

"What it translates to is not a break in containment," Kanabrocki said, CIDRAP News reports.