The Blue Grass Army Depot is reporting a vapor leak.
Army officials say they detected low levels of GB agent vapor--a lethal nerve agent--in the chemical weapons igloo during a weekly inspection.
The igloo contains rockets with the GB agent, they said.
Officials say though "leakers" are relatively rare, they are a normal part of chemical storage operations.
Toxic chemical workers have connected a 1,000 cubic feet-per-minute filter to the back of the igloo to vent it safely.
Army officials add that, at this time, the leak poses no danger or risk to people in Madison or surrounding counties.