Though home safes are often described as fireproof, a close look at labels shows that they're really rated for fire resistance up to a certain temperature for a certain duration -- starting at 30 minutes. Ratings based on standardized tests are provided by the Underwriters Laboratory (UL) as well as other recognized testing services, such as Intertek Testing Services, which confers the ETL seal.
UL rates safes by the heat of the fire they are designed to withstand, the maximum interior temperature during such a fire and how long they can be subjected to the heat of the fire before the interior exceeds its rated maximum temperature. Basic home safes are generally rated to provide 30 minutes of protection from a fire of up to 1,550 degrees Fahrenheit before their interior temperature exceeds 350 degrees Fahrenheit. Such an interior temperature will keep paper (which begins to char at 450 degrees Fahrenheit) as well as hardier computer media (USB drives, memory cards, CDs, DVDs, etc.) safe. The maximum heat and protection length ratings of these basic safes are fine for typical home situations. If you live in an area that's prone to wildfires -- meaning that a house fire that could burn longer and hotter is a possibility -- you might want to opt for a safe with a higher maximum temperature rating and/or a longer protection period.
Safes rated to keep their contents at 350 degrees or below are rated as Class 350 safes. Some fire-resistant safes, called "media safes," are UL-rated Class 125 to keep the internal temperature below 125 degrees Fahrenheit. This is important for more fragile media such as floppy disks, cassette tapes, slides and photo negatives. For most users, a Class 350 safe that keeps the internal temperature below 350 degrees Fahrenheit is enough.
It's also important to pick a home safe that resists water, because firefighters are likely to deluge it. Keep in mind that during a fire, the ceiling or roof may fall in, so impact resistance can also be important -- especially if the safe is out in the open. Labs test for impact resistance by dropping a safe from heights of 15 to 30 feet.
Keep in mind, too, that some personal documents have resale value to potential thieves. Passports, for example, are prime targets. An inexpensive home safe is fine for storing personal documents that have no resale value to a burglar (like your home's deed or insurance documents). The simplest solution is to store valuables in a safety deposit box, while keeping private papers in a small home safe that is closed but left unlocked. Just be sure to choose a safe that resists fire and water when closed. Leaving it unlocked can deter a burglar from just carting the whole safe off, even though it contains nothing he can use.
If you need to keep the home safe locked to protect privacy -- from household employees, for example -- consider a safe that can be bolted in place. If you must keep valuables on your premises, get a safe that carries a UL Residential Security Container rating, which indicates a high degree of security.
When choosing a fireproof home safe, keep these additional tips in mind: