ADVERTISEMENT Pilkington Pyrostop® from Technical Glass Products (TGP) is a fire-rated and impact-safety-rated glazing material that blocks radiant and conductive heat for up to two hours. The UL-classified and labeled product is fire-tested as a wall assembly, allowing unrestricted amounts of glazing in fire separations. See how the design team for the Empire State Building Observatory renovation project combined it with narrow-profile Fireframes® Curtainwall Series fire-rated frames to preserve the city’s spectacular views while also providing critical fire resistance.