A Becton Dickinson sterilization plant in Covington, Georgia accidentally released ethylene oxide into the air last month, according to a local report.

Beginning on Sept. 15, the facility began to experience sporadic elevated levels of ethylene oxide, according to the firm’s indoor ambient air monitoring system. An investigation did not immediately find a root cause.

On Sept. 23, the vacuum exhaust valve for a facility sterilizer was found not fully closed, and the increased levels of ethylene oxide are believed to have stemmed from this deficiency. The valve was subsequently closed, tested and verified.