... 1,non-toxic, zero radioactivity,non-asbestos 2, Fireproof Grade Class A1 3 Fire Times:1.5,hours,2 hours ,4hours. 3,Light Vermiculite ... fireproof doors are filled with vermiculite senior fire-resistant core as the fire doors ... aspects of the corresponding cost savings.6 high fire rating.The maximum time for the fire five hours, plus four hours, three hours ...