Figure H-4. Sandbag walls around tents.
H-4. Expedient Shelters Against Biological and Chemical Agents
a. When CPS systems are not available, well-sealed shelters (TEMPER, ISO, and GP) can significantly minimize or prevent the entry of CB agents. The ventilation system must be turned off, and kept off, before, during, and after the attack. The shelter must be totally sealed during this time to maximize protection. [Table H-3] provides examples of protection values for well-sealed shelters. For example, a well-sealed TEMPER will only permit 1/60 of the CB agent outside to enter the shelter. If a persistent agent is used, be aware of agent off-gassing hazards. Persistent agents can penetrate TEMPER fabric and create a vapor hazard inside. In a CB agent attack, ensure that all staff and patients are protected by wearing their MOPP or are in PPWs.
Table H-3. Ratio at Nonpersistent Agent Concentrations (Inside/Outside) for Different Shelters
| SHELTER | RATIO INSIDE/ OUTSIDE |
|---|---|
| TEMPER TENT | 1:60[*] |
| GENERAL PURPOSE TENT, MEDIUM, WITH COTTON LINER | 1:50 |
| GENERAL PURPOSE TENT, LARGE, WITH COTTON LINER | 1:30 |
| ISO SHELTER | 1:60 |
| [*] THE VENTILATION SYSTEM MUST BE TURNED OFF ON ALL SHELTERS TO PROVIDE THIS LEVEL OF PROTECTION. | |
b. Sealing shelters to prevent entry of CB agents does not require elaborate materials or procedures.
(1) Materials needed for sealing shelters include, but are not limited to the following: