Fire Resistant Document or Record safes are designed and built to protect records, important papers, cash and valuables from fire. Some are also rated for burglary protection.
The manufacturing process for all record or fire safes, manufactured in the United States, is much the same. They begin with a hollow welded or a hollow molded composite metal box or can, this will be filled with a “wet” mix that looks much like concrete, they are dried in kilns, cleaned, finished and painted.
This “wet” mix this is a very specialized product, when it is dried and sets up, it retains cells of moisture within the structure. These cells of moisture, when exposed to heat, change to steam, which is released into the interior of the container. The steam that is released performs two main functions, it keeps the interior temperature below 350 degrees Fahrenheit, for a prescribed time, and also provides a pressure seal for the small openings around the door, keeping heat and flames out. This release of steam is also why anything that will be damaged by moisture including, stamp collections, photographs, audio & video tapes, and computer data, should never be kept in a fire safe. They can be safely stored in a media safe.