“Columbus is responsible for letting plumes of poisonous gas escape into the open air,” said Jared Blumenfeld, EPA’s regional administrator for the Pacific Southwest. “Our goal is to safeguard neighbors and workers by requiring critical improvements to the company’s plant to prevent these industrial accidents from happening again.”

The first accidental ammonia release, in February 2009, sent 217 pounds of poisonous gases into the atmosphere. Six months later, in August 2009, the plant again released an ammonia cloud, this time approximately 200 pounds of anhydrous ammonia was released into the atmosphere.

The August incident resulted in the evacuation of all facility employees and several neighboring businesses. Nearly 30 people from the downwind Genentech campus sought medical attention and 17 individuals were hospitalized. One person remained hospitalized for 4 days. In addition, off-ramps from Highway 101 and several local streets were shut down as a result of the release.

EPA took action following the August 2009 incident, ordering Columbus to complete initial upgrades to its ammonia refrigeration system, including the replacement of safety relief valves and components with any signs of corrosion, and the proper labeling of all its piping. In 2011, the company paid $850,000 in fines to San Mateo County as a result of the incident.

According to EPA, the releases were the result of Columbus’ failure of its general duty of care to identify hazards and to maintain a safe facility and its failure to comply with regulatory requirements for process safety management under Section 112(r) of the Clean Air Act.

“This settlement appropriately penalizes Columbus for violations of the Clean Air Act that resulted in two illegal releases of poisonous gas that put the community at risk, including one release that caused the hospitalization of people in the affected community,” said Ignacia S. Moreno, assistant attorney general of the environment and natural resources division at the Department of Justice.

As part of the Jan. 31 consent decree, Columbus will pay a penalty of $685,446 and spend approximately $6 million converting its refrigeration system to a safer technology that uses glycol and ammonia. The company also will improve its alarm and ammonia release notification procedures.

Anhydrous ammonia is considered a poisonous gas. Exposure to its vapors can cause temporary blindness and eye damage, and irritation of the skin, mouth, throat, respiratory tract and mucous membranes. Prolonged exposure to anhydrous ammonia vapor at high concentrations can lead to serious lung damage and death.