The Decontamination Process is a game mechanic in SCP: Secret Laboratory, which serves to pressure players out of the Light Containment Zone.


The Decontamination Process is an emergency protocol, which C.A.S.S.I.E activates in the event of a containment breach. This event occurs after 11 minutes and 45 seconds have passed in a round. Remaining time until decontamination can be viewed at the Light Containment Zone checkpoint and Heavy Containment Zone elevator systems on small monitors. Once active the process slowly kills any players still in the Light Containment Zone, regardless of their health, including SCPs.

The checkpoints will be opened 30 seconds before the process begins, allowing any stuck players to escape. Any elevators that are down at Lift System A and B will be called up and become inoperable to prevent players from returning to the LCZ. However, the elevators do work if called from the LCZ after the Decontamination starts.

Once the process begins, green gas will start pouring out of vents and slowly kills anything inside the LCZ. The damage taken by human players is 2 per tick and 10 per tick for SCP's.

If a player manages to reach the elevator system and the time hits 0 seconds, players still have a chance to escape as there is no lock for sending the elevator up, only sending it down.


C.A.S.S.I.E can be heard at different time intervals warning everyone the time remaining before the process begins.

At 15 Minutes

"Attention, all personnel, the Light Containment Zone decontamination process will occur in t-minus 15 minutes. All biological substances must be removed in order to avoid destruction."

Decontamination 15m

At 10, 5, and 1 minute(s)

"Danger, Light Containment Zone overall decontamination in T-minus 15 Minutes."

"Danger, Light Containment zone overall decontamination in T-minus 10 Minutes."

"Danger, Light Containment zone overall decontamination in T-minus 5 Minutes."

"Danger, Light Containment zone overall decontamination in T-minus 1 Minute."

Decontamination 5m

Decontamination 1m

At 30 Seconds

"Danger, Light Containment Zone overall decontamination in T-minus 30 seconds. All checkpoint doors have been permanently opened. [The Final Flash of Existence starts to play, timed with the 20 second countdown.] Please evacuate immediately. 20. 19. 18. 17. 16. 15. 14. 13. 12. 11. 10 seconds. 9. 8. 7. 6. 5. 4. 3. 2. 1"

Decontamination 30s

When decontamination begins

"Light Containment Zone is locked down and ready for decontamination. The removal of organic substances has now begun."

Decontamination begin



  • C.A.S.S.I.E's voice warning beep get deeper at each time interval to help players identify how much time they have left before it is even announced.
  • As of 7.1.0, light green decontamination gas can be seen spewing from the ventilation shafts once the Light Containment Zone has been locked down.
  • According to the C.A.S.S.I.E. document , P-B-3 is the assigned code for decontamination. 
  • If a player dies inside the LCZ, their cause of death will be marked as an "highly corrosive substance".
  • Despite saying that it takes about 15 minutes to start, decontamination starts after 11 minutes and 45 seconds have passed in a round.
Mechanics in SCP: Secret Laboratory
Player Mechanics InventoryStaminaRespawn TicketsStatus Effects
Map/Zone Mechanics LockersDecontamination ProcessAlpha WarheadC.A.S.S.I.E.
Other AchievementsMusicAdmin PanelAlignment of Classes914 Upgrade Paths
Plugins ServerMod2EXILED
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