Fire Ratings Explained


Most insurance companies require data media to be stored in units carrying the DIS, Diskette or Class 125 certificates according to EN 1047-1 (VDMA 24991), NT 017 and UL 72 International Standards.  The minimum industry standard for data protection was a product with a 1 hour VDMA certificate.

These data media protection safes have been designed to protect data during the “soak out” period that any cabinet will expose data to in a fire.  A data cabinet by its very construction will store a large amount of heat from a fire.  This stored energy will continue to heat the cabinet's interior and contents long after the fire has been extinguished.  Typically the interior temperature of a data cabinet will peak 6 to 8 hours after a fire has been extinguished.  The modern EN1047-1 (VDMA) and UL72 standards are the only ones which monitor the internal temperatures of the data cabinet until full cooling has occurred.

Magnetic media must be kept below 55º C or complete and total data corruption will occur.

The older, now obsolete, test standards stop recording the temperature inside the cabinet at the end of the fire test heating period.  For example, a 1 hour rated cabinet with an older test certificate is removed from the kiln at the end of the 1 hour heating period, then all temperature measurement ceases and the cabinet is rapidly cooled with water.  The test data media and measuring instruments are then removed.  This is not comparable with the events of a real fire.

The modern EN and UL tests (like the old VDMA) monitor the internal temperatures of the data cabinet until complete and full cooling has occurred.  This ensures that a cabinet with a these certificates actually protects your data for stated time of heating in a fire and does not then let you down during the subsequent soak out period.

A cabinet will be left untouched in a fired building until the fire brigade have completed the extinguishing, making safe and investigation of the fire. This time delay before you have access to your cabinet and its contents must be taken into account.  It is therefore paramount that any data cabinet purchased have the minimum 2 hour EN1047-1 or UL72 rating.  -  Anything less is false economy.


When considering a paper protection product the same rules always apply if anywhere near complete protection is required and therefore units with the P or Class 350 certificates from Internationally recognised standards EN 10471-1 (VDMA) and UL72 respectfully.

Paper is quite robust when compared to data as it will withstand 170º C before gradual discolouration.

If discolouration of the documents is acceptable then products with the Swedish National Testing Institute's (Nordtest) NT 017 FIRE - 60 Paper and 120 Paper certificates offer good paper protection.