Fire chests and fireproof boxes

Fire chests and fireproof boxes for documents, USB drives and hard drives

What a fire chest does, and what it does not

It keeps the contents cool while the room burns around it. The chests here are tested to UL 72 Class 350 for half an hour. In that test the chest stands in a furnace reaching over eight hundred degrees, and the requirement is that the contents come through it. Thirty minutes sounds short, but it is the time that counts: in a home or an office the fire service is on site and putting it out well inside that.

The chests are also separately verified for digital media. Paper takes far more heat than a hard drive does, so protection for paper does not automatically cover a USB stick. That both are covered has been verified separately, and it is stated on each product page.

But a fire chest is not burglary protection. It weighs little enough to be carried out under one arm, and the lock is there to keep the contents away from casual hands day to day, not to resist a burglar. If something has to be protected against theft, a safe is what you want. A common arrangement is to keep the chest inside the safe: then the contents get both the burglary protection and the fire protection.

That is why a fireproof box costs more than a lockable metal one. The difference does not show from the outside. What you pay for is that someone put the box in a furnace and measured what happened inside.

How a fire chest works in a fire

The construction is simple and robust, and it works in four steps:

• First the plastic outer shell burns away.
• Then the edges melt together so the contents are fully sealed in.
• The walls hold a filling material containing bound water, which turns to vapour as the heat rises.
• The vapour carries the heat away from the contents and holds the temperature inside down.

So it is not the insulation alone that does the work, it is the evaporation. As long as water remains in the material the interior stays cool. Once it is spent the temperature rises, and that is the threshold the rating measures.

Watertight, and for exactly that reason a moisture trap

Being sealed against water is one of the chest's strongest arguments. Firefighting water and smoke destroy just as surely as the flames do, and a chest that survives the fire only to be soaked by the hose has helped nobody. Several of the models here are verified watertight for up to seventy-two hours.

But the seal has a downside, and it catches people out. A box that will not let water in will not let moisture out either. Whatever humidity is in the air when you close the lid stays there. When the temperature swings - a cold cellar, a garage, a storeroom - it condenses on the inside.

The result is damp damage and mould on precisely what was meant to be protected. Photographs stick together, paper cockles, and electronics suffer from the condensation. It is slow damage, and it is usually discovered only when the chest is opened a year later.

The fix is simple and cheap. Put a desiccant bag in the chest. It binds the moisture, and once saturated it can be regenerated: dry it in the oven or leave it on a radiator for a few hours and it works again. The bag is in the list below.

This is the fire chest's own problem. A gun cabinet or a security cabinet has generous gaps around the door, so the humidity equalises with the room and no condensation forms. It is the seal itself that causes this - the same property that saves the contents from the fire hose. If a cabinet stands somewhere damp a desiccant bag can earn its keep there too, but then it is the air in the room you are dealing with, not a closed box.

The fire protection bag, the odd one out

A fire protection bag is not a small fire chest. It looks like a folder with a zip and it works in an entirely different way, so it deserves a paragraph of its own.

The material is fibreglass-reinforced plastic with an aluminium coating and a soft inner lining. It closes with a zip and a Velcro fastener, and it is made to protect the contents from heat.

The bag carries no fire rating, and the manufacturer states no protection time. We say so plainly, because it decides how the bag should be used. It has not been tested as fire protection in its own right and should not be bought as a substitute for a chest or a cabinet.

It is made to sit inside something else. That is the manufacturer's own description of the intended use: in a safe that has only limited fire protection. Put the bag holding the most important things into the fire chest, the document cabinet or the safe, and that content gets one more layer between itself and the heat.

Ideal for the things that matter most: USB drives, the external hard drive holding the backup, securities - or photographs, jewellery, cash and passports at home. It also works as a transport sleeve for a laptop or tablet. The bags come in A4 and A3 and are in the list below.

When a chest is enough, and when you need a cabinet

The chest is right when the quantity is small and the contents irreplaceable. Passports, certificates, insurance papers, a will, a backup drive, the memory card with the photographs from the children's first years. Things that fit in a box and that nobody can print again.

The chest is also right when something has to be portable. It can move between home and office, come along in a move, and in the worst case be carried out. A cabinet stays where it stands.

The cabinet is right once the quantity grows. A box meant to hold several binders quickly becomes so heavy that the advantage of being able to carry it disappears. At that point a fire rated document cabinet is both cheaper per litre and easier to work with.

The cabinet is right when thirty minutes is not enough. If you need sixty, ninety or a hundred and twenty minutes, that exists in cabinet form and not in box form. The same goes if the contents are backup tapes, diskettes, negatives or cine film - they take far less heat than paper and need a data media safe.

Size and locks

Start from the paper format. The chests are built to take A4 lying flat without folding the documents, and the bags come in both A4 and A3. Internal measurements are on each product page, and those are the ones that matter - the walls are thick and the external size says little about what will fit.

Expect it to fill up faster than you think. Binders take up disproportionate room in a box. If it is going to be binders from the start, a cabinet is what you should be looking at.

Key lock or keypad. The key lock is simple and has nothing that can run out. The electronic keypad does away with the key, the code can be changed, and several people can have access. Use good quality alkaline batteries, Duracell or Energizer - cheap batteries leak and can put the lock out of action. The Lock system filter shows which each model has.

Finding the right one

The whole range is on this page, so it can be taken in without filtering. To narrow it down, Fire rating, Outer height in mm, Outer width in mm and Lock system sit above the products.

Two accessories belong here and are in the same list: the fire protection bag that adds minutes inside a chest or cabinet, and the desiccant bag that keeps the condensation away. Both cost a fraction of the chest and each solves a real problem.

Not sure? Call us on +46 770 22 01 22. Tell us what goes in the chest and where it will stand, and we will tell you whether a chest is enough or whether you need a cabinet. We would much rather do it before the purchase than after.