Firefighters from the Menlo Park Fire Protection District and the hazardous materials handling team from San Mateo County spent more than two hours Wednesday night dealing with a spill of about 2.5 gallons of a corrosive cleaning agent at Sand Hill Foods Corp., a research and development firm at 1140 O'Brien Drive (Suite B), according to Fire Chief Harold Schapelhouman.

Twelve people evacuated the building, including people from the adjoining suite. There were no injuries, he said. The site is a commercial building in a light industrial district off Willow Road east of U.S. 101.

While employees were cleaning a pasteurization test machine, a hose disconnected and spilled the fluid, the chief said. Someone may not have tightened it as much as needed, he added.

The HazMat team entered the building with level B protection, meaning a protective suit and an air-breathing backpack and face mask, but no helmet or "moon suit," the chief said.

The corrosive nature of the cleaning fluid reflected the intent of getting the testing machine "absolutely clean," the chief said.

After an inspection, HazMat allowed the employees back in to clean up the spill.

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