SAN FRANCISCO — Meat processor Columbus Manufacturing of South San Francisco, Calif. has been ordered by the U.S. Environmental Protection Agency to take action in the next three months to address safety concerns surrounding its ammonia refrigeration systems following a 2009 leak. Columbus has agreed to comply with the order.

According to E.P.A., the plant accidentally released approximately 200 lbs. of anhydrous ammonia into the air during an August 2009 incident. The release resulted in evacuating all facility employees and several neighboring businesses. Approximately 30 people from the nearby Genentech campus sought medical attention and 17 individuals were hospitalized. One person remained hospitalized for four days. Off-ramps from Highway 101 and several local streets were also shut down as a result of the release.

“This release of an extremely hazardous chemical is unacceptable,” said Jared Blumenfeld, regional administrator for E.P.A.’s Pacific Southwest region. “It’s critical that Columbus Manufacturing take specific actions to safeguard its employees and neighbors. As a result of these dangerous accidental releases, the company may also face substantial federal fines.”

Anhydrous ammonia, considered a poisonous gas, can cause temporary blindness and eye damage, as well as irritation of the skin, mouth, throat, respiratory tract and mucous membranes, if exposed to its vapors. Prolonged exposure at high concentrations can lead to serious lung damage or even death.

The facility’s accidental release in August was allegedly caused by a buildup of hydrostatic pressure in a section of piping, which caused the subsequent rupture of a nearby component. Following the incident, E.P.A. and San Mateo County’s Division of Environmental Health Services inspected the facility and evaluated Columbus Manufacturing’s ammonia-refrigeration systems and safety-management systems. The inspections revealed a number of safety concerns regarding the design and maintenance of the facility’s anhydrous ammonia refrigeration system.

As a result, E.P.A.’s order requires Columbus Manufacturing to complete a series of tasks within the next three months including replacing certain safety-relief valves; replacing all components with any signs of corrosion or made from incompatible materials, such as brass; and properly tagging, and labeling all of its ammonia refrigeration system piping and valves. The facility must submit verification to the E.P.A. indicating compliance with all required actions within 105 days of this order.