I-9. If an M256/M256A1 kit is not available, the unmasking procedures take approximately 35 minutes. When a reasonable amount of time has passed after the attack, find a shady area; use M8 paper to check the area for possible liquid contamination. Conduct unmasking using these procedures:
- The senior person selects one or two Soldiers. They take a deep breath and break their mask seals, keeping their eyes wide open.
- After 15 seconds, the Soldiers clear and reseal their masks. Observe them for 10 minutes.
- If no symptoms appear, the same Soldiers break seals, take two or three breaths, and clear and reseal masks. Observe them for 10 minutes.
- If no symptoms appear, the same Soldiers unmask for 5 minutes, then remask.
- If no symptoms appear in 10 minutes, request permission from higher headquarters to signal “ALL CLEAR.” Continue to observe all Soldiers in case delayed symptoms develop.