Most safes built for fire protection come with a UL (Underwriters Laboratories) fire rated labeling. Before purchasing a safe it is important to understand the basics of fire protection standards. To start with you need to define what objects (materials) you are going to place in the safe. UL uses three basic types of materials for testing: paper, computer media, microfilm. Each material has a different degree of tolerance to temperature, humidity and length of time exposed to harmful elements. To allow for these differences, UL tests cover three different temperatures and five different time durations. The temperature noted on the UL label is the maximum temperature allowed inside the fire protective product during the test.
For example, if the temperature inside a safe or file exceeds 350°F, it will fail the UL test for paper rated products. For tapes, cartridges, microfiche, and microfilm, the limit is 150°F (with an 85% humidity restriction); for diskettes, the temperature cannot exceed 125°F (with an 80% humidity restriction). The next part of fire rating is the amount of time and temperature applied to the safe during its testing period. Example: 60 minutes at 1700 degrees Fahrenheit.
Depending upon the classification time being tested, the furnace heat rises at a carefully monitored rate until the specified temperature is reached. One the time and temperature are reached the oven is allowed to cool down. Finally, the product is opened and examined to determine whether the contents are still in usable condition. The interior walls and components are checked for any evidence of heat or humidity damage. Fire and Impact Test: After a product has passed the Fire Endurance Test, another sample of the same product may be tested for fire and impact. The sample is prepared in the same manner as the Fire Endurance Test.
Then it is heated to a specific time and temperature (see chart below). After the product has been exposed for the correct time period, it is immediately removed from the furnace and hoisted 30 feet off the ground. UL then drops the product within two minutes into a pile of broken brick on a concrete base. This is equivalent to a fall from a third story. Finally, a label is certified for the product being tested. Example: Record Protection Equipment Classified By Underwriters Laboratories, Inc As To Fire Resistance Rating: Class_______-____Hr The normal test classes and times are as follows: Class: 350°, 150°, 125° Hour: ½, 1, 2, 3, or 4 Now when you are examining fire rated safes you can simply ask, “What is the fire rating class and time period?