(45c) Shelter-in-place Design Considerations – How Safe is Safe Enough?

Facilities with potentially significant toxic and/or flammable hazards often establish shelter-in-place locations (SIPs) in order to mitigate risks associated with an accidental release of hazardous materials.  Typical toxic risk mitigation strategies regarding SIPs include reliably isolating building ventilation systems in a timely manner upon detection of predetermined concentrations of hazardous gases, making the SIP as leak-tight as possible, and/or providing an effective fallback (evacuation) plan.

While a properly designed SIP can provide significant risk reduction benefits, complex decisions are required to ensure regarding the adequacy of the SIP design and a robust management program needs to be in place to ensure the on-going effectiveness of the SIP and avoid giving personnel a false sense of safety.

This paper explains methods for quantifying effects of SIP parameters of interest and provides guidance for optimizing risk mitigation through SIP design and operation and development of a highly effective fallback/evacuation plan.