Fireproof boxes: a simple precaution

Storing important documents and computer data in a fireproof box or chest ensures peace of mind should the worst happen and your home or office premises experience a blaze. Some of these units also offer water resistance, giving additional protection against sprinklers, hoses and even total immersion through flooding.

The main criterion for choosing a fireproof box must be the nature of the material to be stored inside it. Test criteria and fire rating classifications are focused on three main categories of information capture and presentation.

Paper: for example, passports, certificates, insurance policies, deeds, legal documents and cash (notes).

Digital media: for example, USB / memory sticks, DVDs, CDs, digital cameras, iPods, MP3 players and external hard drives.

Data media: for example, computer back-up tapes, computer diskettes (floppy disks), and traditional internal hard drives. Cellulose based materials such as film, negatives, transparencies and microfiche are almost as vulnerable to the hazards of a blaze as data media so should be stored in a fireproof box designed to protect this type of computer data.

Each type of media starts to degrade at a different temperature, as follows:

Paper:              177 °C / 350 °F

Digital:            120 °C / 248 °F

Film:                66 °C / 150 °F

Data:               52 °C / 125 °F

Although fireproof boxes are mainly designed to accommodate paper, some offer protection for digital media as well, while others have a data protection insert that means mixed media can be safely stored for the specified protected length of time. This is usually 30 or 60 minutes, depending on the test criteria of a particular model.

A fireproof box protects its contents by keeping the storage compartment(s) below the critical temperature level in the heat of a blaze, which is typically around 450 °C but can be much higher, depending on the nature of the materials that are combusting. The construction of the box is double walled, the cavity being filled with a special, heat-absorbing composite. Intumescent seals around the inside of the lid, which swell to many times their original size in a fire situation, ensure that the box is sealed tight shut and thus prevent the ingress of smoke and hot gases.

Portable fireproof boxes have a carry handle and are usually secured by keylocks, with two keys supplied as standard. Most manufacturers offer a lifetime after-fire replacement guarantee as well as the usual limited warranty.