A Guide to Fireproof Safes
The extensive range of fireproof safes, also known as fire safes, on the market today can sometimes make it difficult to decide on the most appropriate solution for a particular storage requirement. There are numerous test institutes, test standards, technical specifications and security ratings, so the aim of this guide is to assist in making an informed choice of product, by highlighting the various issues for consideration.
Different items, different requirements
First and foremost, it is important to consider the physical nature of the items to be kept in the fire safe. Sensitive data and irreplaceable documents are major candidates for protection from fire and its associated hazards, such that test criteria and fire rating classifications for safes are focused on three main categories of information 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 / magnetic media: for example, computer back-up tapes, computer diskettes (floppy disks), traditional internal hard drives, video tapes and audio tapes. Cellulose based materials such as film, negatives, transparencies and microfiche are almost as vulnerable to the hazards of a conflagration as data media and should therefore also be stored in a fireproof data safe.
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|
Data media must also be protected from the electro-magnetic interference generated by a fire, as this will corrupt information that is magnetically captured.
A fire safe comes under attack externally from smoke, flames, dust and hot gases, with the temperature of a conflagration typically rising to around 450 °C / 842 °F, although this can be much higher depending on the nature of the fire and the materials that are combusting. However, rising humidity levels inside the safe can also constitute a hazard for vulnerable data media and film; the critical levels above which such items start to degrade are as follows:
|Film:||85% humidity restriction|
|Data:||80% humidity restriction|
How does a fireproof safe work?
As noted above, one of the problems that can arise when storing items in a fire safe is that, if the wrong specification is chosen, they could be destroyed by internal moisture levels rather than the heat of the blaze. This is because of the way in which a fire safe is designed in order to keep the interior as cool as possible throughout the fire. Typical construction features a double-walled steel body whose cavity is filled with a special fire resistant composite. Although this composite can vary between brands of safe, it will contain a hydrate such as alum or gypsum that releases water vapour when heated. Some of this water vapour (steam) is channelled into the interior of the safe, where it serves both to regulate the internal temperature and also to create a pressure seal against the external heat of the fire. The pressure / humidity levels are controlled by the strategic placing of vents, or external release holes, in various parts of the safe: for example, the back, top, underneath and the front of the door, beneath the fascia. This enables some of the steam to escape into the fire. These precision engineered features reinforce the fire resistance of the safe, which is designed so that all gaps are sealed when the materials used to protect the interior react to the fire: for example, the intumescent strips fitted to the safes main cabinet and any compartments within it, plus the inside edges of the door, which swell to many times their original size in the heat of a blaze and seal the safe tight shut.
It should be noted that protecting against critical levels of humidity inside the safe is not the same as water resistance (although some safes do offer this latter feature). Water resistance refers to water hazards from outside sources, such as sprinklers, hoses or even flooding to a depth of several metres. This type of protection is achieved, for example, by fitting airtight, water resistant seals to the door and any door(s) of internal compartment(s) of a safe.
What type of fireproof storage?
Up to this point, reference has only been made to safes, but there are many different types of fire rated storage units, from smaller, top opening fireproof boxes and chests through to filing cabinets and cupboards as well as bespoke strong rooms and vaults. As discussed above, the main criterion for choosing a fire resistant storage unit must be the type of media that requires protection. It is possible to store mixed media: for example, some models of fire resistant cupboards and filing cabinets, which are principally designed to protect paper, have optional data protection inserts that enable data media to be safely stored inside them as well.
Another important point to consider, especially when buying a data safe, is that its internal dimensions will be much smaller than its external appearance might at first suggest. This is due to the amount of insulation material required to keep the temperature inside the safe below the critical 52 °C / 125 °F level. Care must therefore be taken that there is enough space inside the safe to meet the storage requirements.
It may also be the case that, as well as fire resistance, the safe must offer burglar protection. From the point of view of insurance, it is recommended that checks are made with the underwriters to ascertain the level of insurance cover they are prepared to offer in respect of the valuables and / or cash to be stored in the safe, as this will depend on a number of factors, including the location of the safe, and not just on the insurance rating per se. For example, most fireproof units are free-standing, as drilling holes for floor or wall mounted fixings are likely to compromise the integrity of their fire resistance. This is not such a problem for larger units but, if it were possible for a burglar to physically remove the safe, consideration must be given to the wider security of the premises in which it is housed. When choosing a fire safe with security protection, prominent test standards to look for are EN 14450-S1 and S2 and EN 1143-1. These are European norms for resistance to burglary attack, with the S1 security standard giving cash cover of £2,000 or valuables cover of £20,000 (the lowest level for independent testing) and S2 giving cash cover of £4,000 or valuables cover of £40,000. EN 1143-1 is the next level up, with a grading system ranging from 0 through to 5 (e.g. 0 = £6,000 cash / £60,000 valuables cover; 5 = £100,000 cash / £1,000,000 valuables cover). These independent security ratings are very important when it comes to insuring one's valuables in a fire safe.
Other issues to consider include the length of time for which fire resistance is required, i.e. the fire rating. Fire test standards range from 30 minutes through to 240 minutes (i.e. 4 hours), with the safe exposed to temperatures ranging from 843 °C / 1550 °F to 1093 °C / 2000 °F, depending on the testing house. Some of the main fire test standards and test institutes are referenced below; the list is by no means exhaustive but does serve to indicate the range of tests and how these are variously applied.
Fire test institutes, standards and fire ratings
The pan-European standard EN 1047, applied under the auspices of British Standards as BS EN 1047, contains some of the most rigorous test criteria for fire safes, with EN 1047-120 Dis perhaps the most stringent of all. This requires the data safe to be heated in a furnace to over 1100 °C / 2012 °F for two hours, with the temperature inside the cabinet not to exceed a maximum 52 °C / 125 °F. After the two hour period has elapsed, the furnace is switched off and the safe left inside it, to cool down. This is known as the 'soakout' period, the purpose of which is to ensure that the ambient temperature in the furnace does not raise the internal temperature of the safe above the critical level for data / magnetic media. EN 1047 has recently superseded the German VDMA test, but is carried out in the same test house and by the same test institute in Germany (VdS). A relatively new European certification, ECB.S, tests to both fire and security European standards, including inter alia secure safe cabinets to EN 14450 and data cabinets to EN 1047-1.
The Swedish equivalent of this test standard, NT FIRE 017-120 Dis, requires the data safe to be heated in a furnace to 1090 °C / 1994 °F for two hours. Again, the temperature inside the cabinet must not exceed the maximum 52 °C, and the safe is deemed to have passed the test when the two hour period is up and this criterion has been fulfilled. There is no subsequent 'soakout' period. MTS DIP 120-60DM (Grade B) is a Chinese test performed in accordance with Swedish test criteria for digital media, where the internal temperature of the safe must not to exceed 120 °C / 248 °F.
In America, the leading test institute is Underwriters Laboratories (UL), whose relevant standard is UL 72. In respect of data media, the temperature inside the cabinet of the safe must not exceed 52 °C / 125 °F, with humidity restriction of 80%. For the 120 minute test standard, for example, the safe is heated in a furnace to 1010 °C / 1850 °F for two hours, after which the furnace is switched off and left to cool down, with the safe still inside it. The cooling process can take up to 68 hours, during which time the temperature inside the safe can continue to rise. UL notes that it is at this critical point that many manufacturers fail the test; only those products whose internal temperature and humidity levels remain below the test limits for the entire heating and cooling process are awarded UL classification.
Fire test standards for paper include NT FIRE 017-60 Paper and -90 Paper, which require the safe to be heated in a furnace to 945 °C / 1733 °F and 1050 °C / 1922 °F for 60 and 90 minutes respectively, with the temperature inside the cabinet not to exceed 175 °C / 347 °F. The UL equivalent to the 60 minute test standard is UL 72 Class 350-60; the safe is heated in the furnace to 927 °C / 1700 °F, with the maximum temperature inside it not to exceed 177 °C / 350 °F.
Another test to which some types of fire safe are subjected is the impact or drop test, which simulates the conditions when a building collapses and the safe falls from a height; the test standard is a drop of 9.1 metres (30 feet). An explosion test involves heating the furnace to a specified temperature (e.g. 1094 °C / 2000 °F for the UL test) before the safe is placed inside for a period of up to 30 minutes. The rationale behind this is that sudden exposure to intense heat may cause the fire retardant composite inside the safe to explode. If no explosion takes place, the furnace is switched off after the test period has elapsed, the safe is left to cool, and is then broken open and inspected as usual. Explosion and impact tests are sometimes combined, with the safe first subjected to the explosion test, then dropped 30 feet and finally reheated and cooled again before being broken open and inspected.
Securing a fire safe against unauthorised access under normal conditions of operation is clearly of importance, due to the sensitive and / or valuable nature of the items stored within it. There are two main types of locking device for fire safes: keylocks and electronic locks.
Keylocks for fire safes (apart from the underfloor versions) are usually supplied with two keys that are either dimple cut or, for higher security, double bitted. This limits access to the safe to two people, which can be seen to increase security, but can also pose a problem if, for example, one of the keyholders leaves the organization without returning the key. The worse case scenario is that the entire lock has to be replaced. As the technical specifications of a safe increase, the locking device also tends to become more sophisticated; the VdS class 1 keylock, for example, offers a high level of traditional key operated security.
An additional level of security protection is offered via a key plus combination lock, in which a combination dial is located adjacent to the cylinder lock. This enables dual custody of the safe, with one person knowing the combination and the other holding the key. The former can either be a fixed wheel dial, which is set to a particular combination for life, or a changeable combination, which is a more expensive option.
Electronic locks are powered by batteries, which may be located either inside or outside the safe. In the former case, a key override is always provided in case of battery failure resulting in lockout. An advantage of electronic / digital locks over keylocks is that as many people as required to have access to the safe can be given the keypad code, which can easily be changed if someone leaves the organization. As with the keylock, the VdS class 1 electronic lock offers a high degree of security, including the option of a time delay function.
It is also possible for digital locks with programmable codes to incorporate an audit trail, in which individual key codes are associated with individual users. This enables a record to be generated of who has accessed the safe and when, which is either displayed on an integrated screen via a management code or, in the more sophisticated versions, in downloadable form to a laptop.
In recent years, technological advances have resulted in the biometric lock, which depends on either fingerprint or iris recognition to open it. Biometric fingerprint recognition locks capable of holding up to 100 users have already been incorporated into some models of fire safe, with this groundbreaking technology now setting a pattern for the future.
Reviewed: 31/07/2018 (doc:61 V1.0) Our articles are reviewed regularly. However, any changes made to standards or legislation following the review date will not have been considered. Please note that we provide abridged, easy-to-understand guidance. To make detailed decisions about your fire safety provisions, you might require further advice or need to consult the full standards and legislation.