During the EN1047-1 test, safes are heated in a furnace to 1049° C for one or two hours respectively, depending on the rating being tested.
Once the time has elapsed, the furnace is extinguished and the safe is dropped from a 9 meter height onto a gravel floor (to simulate structural impact) and left to cool. Safes often fail during this part of the test due to damage to the unit or if they continue to absorb ambient heat resulting in higher than permitted humidity.
For products designed to protect digital media the temperature cannot rise above 50°C, while humidity may not exceed 85%. Safes that meet this requirement are designated as S60DIS or S120DIS ( 60 minutes / 120 minutes)