P-B-3 Zone-wide Decontamination (S) is a mechanic in SCP: Secret Laboratory that locks the Light Containment Zone after a set period, preventing players inside the Zone from prolonging the round. The process is announced and initiated by C.A.S.S.I.E. as an emergency breach procedure.
This mechanic is announced to the Light Containment Zone as a decontamination procedure scheduled in 15 minutes. A 15-minute timer then displays at checkpoints and at elevators leading towards the Zone. The timer counts at an faster rate, lasting 11 minutes and 45 seconds in real time.
As the round progresses, C.A.S.S.I.E. will announce the procedure's status to the Zone at the 10, 5, and 1 minute mark. At the 30-second mark, C.A.S.S.I.E. will announce a countdown. Checkpoint doors will permanently open. Elevator doors are not automatically called.
Once the timer stops, the process closes and locks all doors in the Zone. Vents in the zone will pour out lime, corrosive gas which damages all players still in the Zone, including SCPs. This is announced to the entire facility. The only methods of escape is to teleport out via a portal for SCP-106 or via Remote Admin. The elevators connected to the Zone will automatically call towards the Heavy Containment Zone.