Public health officials in the United States have decided to temporarily halt work in several of its high-security laboratories due to concerns over the safety of air hoses used by workers.

The Centers for Disease Control and Prevention on Friday, Feb. 17, shut down four biosafety labs in Atlanta because the air supply hoses attached to suits of workers were never approved for that use.

Air Hose Safety

Air supply hoses are designed to protect workers from exposure to deadly viruses in the laboratories. About 100 CDC workers have used these air supply hoses, but officials said these were never intended to be used in carrying breathable air.

The CDC learned the issue days before, on Feb. 13, and said it had been in the process of ordering replacements for the equipment for the first time ever since the containment labs went "hot" almost 10 years ago.

Stephan Monroe, lab safety associate director at the CDC, said there is no reason to suspect that the hoses contain toxic material.

"We have no evidence that anybody has suffered ill health effects from breathing air that came through these hoses," said Monroe.

Monroe said the agency has been routinely testing the quality of the air tank that feeds the hoses to make sure that it meets guidelines set by the Occupational Safety and Health Administration.

The CDC is still conducting inspections and safety tests to find out whether researchers have encountered harmful chemicals that passed through the air hoses. Results will be out next week.

Lab Incidents

A report by USA Today revealed that the same air hoses have had a history of disconnecting from the full-body suits of CDC workers as they perform experiments on lethal and fatal pathogens such as Ebola. In May 2013, a CDC worker emailed the news agency saying that the air hose connecter came off the suit while working.

The CDC took two years to respond to the case, but after an appeal requested by the news agency, the House Energy and Commerce Committee has asked the CDC to give a full accounting of all similar lab incidents since 2012.

Meanwhile, Monroe said he doesn't think Monday's incident had anything to do with disconnected air supply hoses. When they contacted the company that owns the firm that built the hoses, the CDC was told that the equipment was not approved for use with breathable air. The name of the company has been undisclosed.