Newport -- Tests ruled out the presence of deadly VX nerve agent in the air at the Newport Chemical Depot after a monitor set to detect the chemical sounded Tuesday, depot officials said.

The monitor began beeping around 3 p.m. in an area where workers were dismantling the former VX production facility, depot spokeswoman Terry Arthur said.

Medical staff immediately checked 10 workers for possible exposure while an on-site laboratory analyzed the monitor to determine whether VX was present, Arthur said.

The monitor did not malfunction, she said, but detected some sort of chemical -- possibly one that was a precursor to VX or even a chemical present in pesticides used in the agricultural area near the depot. Arthur did not know whether the sample would be sent for further testing to determine what substance set off the monitor.

The monitor "is set so it is very sensitive for a reason," she said. "We would rather deal with false alarms than have a chemical agent present and not know it."

VX was manufactured at the Army's Newport Chemical Depot until 1969, when then-President Richard Nixon issued a moratorium on the production and transport of chemical weapons. The final two batches -- more than 1,200 tons of the oily liquid -- have been stored at the 7,000-acre complex ever since.

The Army plans to neutralize the VX in Newport, then ship the byproduct, a caustic chemical called hydrolysate, off-site for destruction.

From Star and news service reports