Described is an approved dynamic construction for effectively thermally insulating and sealing of a safing slot between a floor of a building and an exterior wall construction wherein the exterior wall construction comprises a curtain wall configuration defined by an interior wall glass surface including one or more aluminum framing members, wherein the vision glass extends to the finished floor level below. The dynamic, thermally insulating and sealing system comprises a first element for receiving the insulating elements and positioned in the zero spandrel area of a glass curtain wall construction including only vision glass to maintain thermally insulating and sealing of the safing slot during exposure to fire and heat as well as movement in order to maintain a complete seal extending across the safing slot.