Routine testing at a pharmaceutical plant owned by GlaxoSmithKline plc found the bacteria that causes potentially fatal Legionnaires’ disease, Reuters reported. But the company has sought to reassure customers, confirming on Aug. 12 that medications produced at the plant in Zebulon, North Carolina, are not affected.

“No employees are sick and no products have been compromised,” spokeswoman Jenni Brewer Ligday said in an email. “Medicines were not exposed to the bacteria.”

The manufacturing facility was closed on Aug. 11 after tests showed the presence of Legionella bacteria in a stand-alone cooling tower.

The site’s cooling towers maintain the right temperature and humidity for manufacturing and working conditions. However, none of the air or water released by the cooling towers comes “directly into the building or in contact with any of the products,” Ligday explained.

GSK said that it would clean and retest the cooling towers before the site goes back into operation, adding that it was taking these precautions “to ensure the health and safety of our employees, as well as the safety and integrity of our products.”

The Zebulon factory makes around 30 different products, including Asthma drug Advair and HIV treatment Combivir. GSK expects to reopen the plant within the next few days.

People can contract Legionnaires’ disease when they breathe in water vapor or mist containing the bacteria, according to the Centers for Disease Control. It does not spread from person to person.