Up to 75 employees at the Center for Disease Control and Prevention headquarters in Atlanta may have been accidentally exposed to live anthrax, an infectious disease.

The CDC recently released a media statement informing the public that they need not be concerned, and that the workers at risk are currently being monitored. The level of risk was categorized as “very low.”

Investigators determined that the anthrax bacteria samples were not completely inactivated before being used for experimentation. The researchers, thinking the samples were inactive, did not put on protective gear.

Leonard Cole, a bioterrorism expert, said that in the worst cases, “if you’ve inhaled [anthrax] spores and if they are very lethal, one begins to get—as they say—the standard flu symptoms, high fever, malaise,” as reported by CNN.

The CDC assures the public that the issue will be further examined, and that it will report “all steps [it] takes to improve lab-safety processes as a result of this incident.”