Washington ( CNN ) -- It 's a highly secured , sophisticated research lab studying deadly diseases such as bird flu , monkeypox , tuberculosis and rabies . It 's in a facility called Building 18 , which cost taxpayers $ 214 million . And now , the Biosafety Level 3 lab at the Centers for Disease Control and Prevention in Atlanta is also the subject of a congressional investigation after a potentially dangerous airflow leak at that lab , CNN has learned . The leak occurred on February 16 , when air flowed the wrong way out of a germ lab into a clean-air corridor , rather than through the powerful HEPA filter that cleans the air , congressional sources and CDC officials said . Visitors touring the facility were in the clean corridor when they observed a puff of air being pushed out from the lab through a slot in a door window . CNN recommends : Deadly bird flu could become airborne . If experiments had been under way at the time of that air leak , experts say , unprotected visitors could have been exposed to deadly germs , although an epidemic would have been unlikely . According to U.S. Rep. Michael Burgess , a Texas Republican and a medical doctor , the House Energy and Commerce Committee has asked the CDC for documents about that incident . The request came in the wake of a report on internal CDC e-mails about the incident , first reported by USA Today last week . `` The biggest concern was that there was a contingent of visitors who were walking through the building , '' Burgess said . `` And had one of those people been stricken or made ill or worse , obviously that would have been devastating . '' The lab handles small mammals such as rats , ferrets and mice as part of its experiments with pathogens , according to CDC officials . They say animals were in the lab at the time of the air leak , but they were secured in filtered cages . CDC officials say the lab was clean , was not active at the time , and no one got infected . `` At no time during recent incidents featured in the media were CDC workers or the public in harm 's way , '' agency spokesman Tom Skinner said . `` This unique facility features multiple security layers specifically designed to protect workers and the public in the event of an incident . '' In a statement released to CNN , Burgess ' committee said , `` We will actively work to find out if there are additional concerns or incidents associated with Building 18 . Any anomaly or breach is of concern , and we will work to ensure the integrity of the facility is maintained and that our scientists are safe . '' There has been at least one other safety-related incident in that same building where February 's air leak occurred . In 2008 , it was discovered that a high-containment lab door was sealed with duct tape . That incident was first reported by the Atlanta Journal-Constitution and confirmed to CNN by Skinner . Robert Hawley , former safety chief at the U.S. Army Medical Research Institute of Infectious Diseases , said the CDC has many safety layers in place at its labs . Hawley says researchers at the Biosafety Level 3 lab work in biosafety `` cabinets '' within the lab itself . `` Nothing is handled outside that cabinet , '' Hawley said . `` So they 're working with minute amounts of material , and the chances of aerosol are negligible . '' But there are questions about a possible cover-up . In an internal e-mail , reported by USA Today , CDC biologist Kismet Scarborough said the centers `` ... will do anything ... to hide the fact that we have serious problems with the airflow and containment in this whole building . '' CNN has not been able to independently verify that e-mail . But in response , Skinner said , `` CDC will continue to take an open , transparent and inclusive approach to address any safety challenge in a manner that will ensure the safety of our workforce and the public . '' Skinner said the agency `` intends to cooperate fully with Rep. Burgess and the committee to address any questions they may have about Building 18 at CDC . '' CNN 's Miriam Falco contributed to this report .
A February air raid at a high - security CDC facility draws congressional attention . The CDC said ` ` at no time '' were workers or the public in danger . A House panel wants to know whether there are ` ` additional concerns or concerns ''