During use of the shelter-in-place technique, what should be done to the ventilation system?

During the shelter-in-place technique, turning off the ventilation system is crucial to prevent outside hazardous materials from entering the building. This measure helps to maintain a safer indoor environment by creating a barrier between those inside and the external air that may be contaminated.

While it might seem beneficial to keep ventilation systems operational to maintain air quality, during a hazardous materials incident, such as a chemical spill or release, the risk of drawing in harmful substances from outside increases significantly. Therefore, the focus should be on sealing the space and stopping any influx of potentially dangerous airborne contaminants.

By turning off the ventilation system, individuals can additionally take steps to seal windows, doors, and any gaps where air could enter, enhancing the effectiveness of the shelter-in-place strategy. This method minimizes the risk of exposure and protects occupants from inhalation of toxic substances.