Here is an example from AMSEC on the different temperatures during a fire starting from the interior temperature of the safe, the temperature of an average house fire and what fire ratings their safes achieve. The majority of safe manufacturers list their safes as "fire-resistant" instead of fireproof.
There is a good reason for this. In order for a fire-safe to successfully resist fire, the special composite material sandwiched between the outer and inner steel walls gives off moisture. This creates steam inside of the safe. The steam (according to the Law of Physics) will not go any higher than 350 degrees Fahrenheit. Therefore, the fire labels on all fire safes state the length of time tested and that the safe will maintain a temperature of 350 degrees Fahrenheit or less inside the safe. For example 1 hour at 1700 degrees Fahrenheit.
In building the safe, each manufacturer has to ensure that the "steam" created by the composite fire material will be released from the safe. In order to achieve this, each safe by the nature of the engineering cannot be airtight. The reason for this is because they have to release the steam created inside of the safe while the fire is raging outside. This is why most safe manufacturers do NOT state that their safe is "fireproof". The companies who have been making safes for many years such as Gardall, FireKing, and AMSEC will state, "fire-resistant" rather than fireproof.
The safe will still protect your paper documents, however, when the fire composite material runs out of moisture (usually after the 1 hour, 1.5 hours or 2 hours that it is rated for), the safe will no longer resist the fire. Fortunately, most fires that burn without any water being poured on them will run out of fuel to burn at high temperatures within the first hour. It all depends on what type of material is burning and how much of this material is available.
Check with your local Fire Department to get advice on how long of a fire rating your safe should have.
- Are you close to the fire department and live in the city? A 1-hour fire-rated safe should be fine for your needs.
- Are you out in the country and it will take the fire department quite a bit of time to arrive to put out the fire? We recommend a 2-hour fire safe in this case.
Typically we recommend a minimum of a 1-hour fire rating for any fire or burglar fire safe.
If your budget can afford it a 2-hour fire rating is better. If you are confused about which fire-rated safe to purchase for your home or business, give us a call at 800-207-2259 and we can help you pick which one will work for your budget and needs.