Risks resulting from shelter-in-place include:
- SIP reduces exposure but does not eliminate it. Over time, small amounts of an airborne contaminant can enter a structure, resulting in the exposure of occupants to the hazard. Once inside the structure, these contaminants are trapped. If the source of the hazard is abated, the concentration of the contaminant outside the structure will then be reduced or eliminated.
The concentration of the contaminant inside the structure can then be higher than the concentration outside.
- If buildings are old and/or poorly-maintained, SIP can be less effective due to leakage of air and contaminants into the building at windows, doors and other breaches. As a result, the building does not offer appropriate protection from the hazard.
