Fire Resistance Testing

Have you ever really wondered exactly how your safe or vault earned its fire rating? There are a lot of interesting details to be found in how these tests are designed and conducted that should hopefully bring you some peace of mind. Without the background information a fire rating is little more than a guarantee which is only as good as the entity that makes it. Fortunately the pricey words guaranteeing your safe’s durability in the event of a fire are coming from a very accountable source. The Underwriter’s Laboratory has been testing the fire resistance of various materials and safes for decades so that you don’t have to worry about the details. However, if you are interested we’ll look at exactly what it takes to get the UL seal of approval here.

UL 72 Fire Endurance Test The Underwriter’s Laboratory standard number 72 is a code used to signify a test for the protection of records and documents in the event of a fire. This rating has a number of sub classifications depending on the desired internal temperature in the event of a fire. The UL-72 class 350 is specified for paper products because above 350 degrees they may warp and information may be lost. The UL 72 class 150 is used for magnetic tapes and the class 125 is used for flexible discs. Additionally these are further classified with a timestamp to measure the amount of time they can be exposed to fire and still retain the desired internal temperature. So, what does it take to get one of these rating? The basic premise is pretty simple: UL dumps these safes into a furnace with a temperature of 1,700 degrees Fahrenheit (the average house fire is only 1,100 F) and lets them sit for the intended duration at the desired temperature. Afterwards they are left to cool off in the furnace which can be a lengthy process almost up to 3 days. This is where many safes may fail the test as the temperature and humidity can rise beyond the initial exposure limits. The safes are then opened and the documents and records and checked to see if they are still viable and have retained all of the information they were supposed to. Additionally the interior walls are checked for evidence of heat or humidity damage. After passing the test a safe can be re-tested after a year and must again pass to retain its fire rating. UL 72 Fire and Impact Test This is where things really get fun for the UL testing team. Impact testing must make for some pretty spectacular excitement. The basic premise of these test is similar to that of the fire endurance test but rather than let the safe cool off in the furnace it is removed and raised 30 feet at which point it is dropped on a pile of broken bricks on a concrete base. This is supposed to emulate the third floor of a building in the event that a fire has damaged its structural integrity to the point that it collapses. After it has been dropped it is turned upside down and reheated again to see if it has retained its ability to resist fire. Talk about a thorough test. Anyways, now that you know a bit more about the details behind your fire rating you can rest easy knowing that the people carrying out these tests are quite thorough and are doing their best to try and destroy the contents of your safe (or at least your safe's cousin).