History Of Safes

In centuries past, humankind worshiped fire because they feared it. They saw it ravage palaces and dwellings with devastating results. So much of the written records of early human civilization are gone because of the lack of protection of these documents.

Early civilizations went to considerable lengths to preserve their records. Egyptian temples maintained dedicated archives, the House of Life and the House of Books, where papyrus rolls were stored on wooden shelves and in chests. Mesopotamian scribes kept duplicate copies of important documents in separate archives, sometimes sealing a second copy inside a clay envelope. The Greeks centralized Athens' public records in the Metroon and inscribed their most durable records on stone and bronze.

As written records grew more valuable, people turned to protective devices to house them. Feudal lords built underground vaults and stationed trusted guards to watch over them. Merchants of the 16th and 17th centuries used the iron-banded strongbox, the treasure chest of pirate-story fame, built of iron, or of oak bound with iron.

From the 1820s and 1830s came the iron "safes," with inner walls of stone, plaster, wood, cement, brick, asbestos, mica, alum, chalk, clay, or simply dead-air space. Safes that genuinely protected their contents in a serious fire, though, were not marketed until the early 1840s.

The first standardized tests for the adequacy of safe protection were not made until the late 1910s, however. These tests caused radical changes in safe construction because they proved many of the old theories of protection false. Safe equipment today, thanks to technological progress and thorough testing, can protect a modern business's records far better than anything earlier generations had.

Selecting the Right Safe is an Important Decision!

The selection of a safe is a more serious obligation than the selection of other types of office equipment. If a chair, desk, or printer does not do what it was supposed to do for the customer, an adjustment is easily made. A replacement or an alteration can be made and the only harm done is a little delay and some annoyance.

But what happens when the safe you chose fails to perform? It gets tested by fire, and after the fire it is too late to make replacements or adjustments. A 2021 Federal Reserve Small Business Credit Survey found that 63% of small businesses that reported natural-disaster losses were forced to close at least temporarily.

Any Safe is Safe – Sometimes

Almost any safe, rated or not and regardless of its age, will withstand some heat for some length of time. How much protection you actually get depends on the fire itself: how hot it grows, how close it burns to the safe, and how long it lasts.

Ordinary steel files come through some fires intact, and unprotected records sitting on a shelf or desktop can come through a short office fire. What matters is how hot the fire gets and how long it burns. That is the catch, and it is easy to take the wrong lesson from it: coming through one short office fire is not the same as protection you can count on. A plain steel file cabinet or an unrated steel box has nothing built or tested into it to hold down an interior temperature, so it may come through a brief fire and fail completely in a hotter or longer one. If you want records you can rely on after a fire, start with a fire-rated safe. A one-hour UL Class 350 rating is a sensible floor for paper, with 90 minutes or two hours worth considering if you are farther from a fire station, and our fireproof home safes are rated and tested for exactly that.

Safes Have Certified Security

No firm can afford to test its own safe equipment in an office fire. Consequently, new safe models are given extensive tests by manufacturers and by private testing laboratories before they are put on the market. Established safe models are also taken off the regular assembly line periodically and given tests to see that they still conform to their ratings.

Underwriters Laboratories is the primary testing agency for safes and vaults in the United States. UL began in 1894 under the sponsorship of the National Board of Fire Underwriters and became independent in 1936. Today the testing and certification business operates as UL Solutions, a publicly traded company, alongside the nonprofit UL Standards and Engagement, which develops the standards themselves.

Underwriters Laboratories tests the safes supplied to them by manufacturers and authorizes the use of a series of labels according to the types of test which the equipment has successfully passed.

Learn More About Burglary Ratings

Learn More About Fire Ratings

How to Make a Safe

The modern fire safe depends on a blanket of steam to protect the documents within it. The common insulation elements like glass wool, shiny foils and the others used in refrigerators, stoves, and home construction give little protection against the intense and prolonged heat developed in a building fire.

The older safes utilized free moisture retained in the cement and water mixture used for insulation. This water evaporated over the years and with it went the potential steam protection. This free water also made damp safe interiors, musty papers and rust. Newer formulas and treatments produce a safe insulation with the water retained in permanent crystalline form. As the heat increases during a fire, these crystals turn to water and then to steam which blankets and cools the interior of the safe. For a closer look at how today's manufacturers build this protection in, see our guide onhow safes are fireproofed.

The insulating element of the safe can be made in either one of two methods. It may be cast in a one-piece, oven-dried monolith, then the metal shell built around it. The second method is to form the metal shell first, then pour the insulation mixture into the shell.

Sudden heat changes during a fire can cause a safe to rupture. The cause is steam pressure, not fire itself: the water held in the insulation flashes to steam under rapid heating and expands roughly 1,600 times its liquid volume. UL 72 screens for this with an explosion hazard test, inserting the safe into a furnace already preheated to 2,000°F. Quality manufacturers design in provisions to relieve that pressure.

One point the older material predates: a standard fire safe carries a UL Class 350 rating, which keeps the interior below 350°F to protect paper. That threshold is still too hot for digital media. Hard drives and USB drives need a UL Class 125 rating, while backup tapes, microfilm, and microfiche fall under Class 150. Both tiers limit humidity as well as temperature, which Class 350 does not, and that is why they require different insulation and sealing. Many buyers cover this with a dedicated data media safe placed inside a larger fire safe.

How Standardized Testing Changed Safe Construction

It was not until the late 1910s that safes were given any reasonable tests for protection against fire hazards. The results of the first standardized tests proved that many of the old theories about adequate protection were false. After the tests, manufacturers changed their construction methods radically.

A massive, heavy safe looks like it can give plenty of protection. But if it is old, it has probably lost most of the fire-resistant properties it once had. If it was made before the late 1910s, it never had some of the protection we consider necessary today.

Most safes made before the late 1910s were insulated with plain water and cement. When the free water evaporated, none was left to make the steam blanket that protects records from heat.

Older safes depended on the supporting strength of their outer shells alone or on heavy bands at the front and back. At 1,000°F, well within the range of an ordinary building fire, structural steel loses roughly a third of its strength, and by 1,200°F it has lost close to two thirds. With the support weakened, the safe would warp and let the heat in. Any drop during the fire would burst the safe and open its contents to the flames.

Safe construction methods have changed radically since testing has been conducted scientifically. In the older safes, the heat was rapidly transmitted to the interior of the safe by its metal hinges, spindles and handles. Openings between the door and frame often permitted direct access for the heat of a fire. Solid steel fittings in the door and jamb conducted the heat quickly.

Doors are now tongue and grooved in a design that impedes the path of the heat. Casings for the insulation are of light material and assembly methods are engineered so that there is a minimum of heat penetration to the interior of the safe.

Relocking Devices

Knocking off the combination lock and driving out the spindle was a favorite method of opening a safe at one time. Safes can now be equipped with a relocking device, however, which foils this practice. The relocking mechanism is very sensitive to any tampering with the combination lock and any pounding will immediately deadlock the bolt work of the safe.

Relockers are now standard on rated safes rather than an optional extra, and a relocking device is a required component of any UL 687 TL rating. Insurers today generally set coverage limits based on a safe's overall burglary rating rather than crediting individual features.

There are occasions within the business office where the combination of the safe is known only by one or a few persons, yet a number of employees are required to work with the contents of the safe.

An older method of dealing with this problem is the use of a separate key-locked inner door. Authorized employees are issued keys to the inner door but do not know the combination to the safe. The inner door has dropped in popularity, but it is still available on some safes.

The modern approach to the same problem is locked interior compartments. Employees are issued keys to the compartments they are entitled to enter. An alternative method used on some safe models is a separate key-locking dial, which adds a key lock in the center of the combination dial. The key must first unlock the dial before the combination can be dialed, so opening the safe takes two people: one holds the key while another knows the combination. That dual-custody arrangement keeps any single employee from opening the safe alone. If you are replacing or upgrading a lock, oursafe locks collection covers mechanical, electronic, and biometric options.

WHAT YOU NEED TO KNOW ABOUT THE VALUE OF YOUR RECORDS

Many business people take their record keeping for granted. It is a necessary nuisance. It is not that they think records are not important but too many business people fail to realize that their business records are what keep them in business.

For over 40 centuries, humans have been protecting their personal and valuable possessions in strong boxes. It has been a relentless challenge for the designers and manufacturers of safes to outwit the safe crackers and burglars of the world.

Modern safe and vault construction can protect against a wide range of hazards, but no safe is impenetrable. A rating tells you how long a safe holds against a defined attack, not that it cannot be beaten.

Despite remarkable advances in the design and production of protection equipment, many businesses still rely on the wrong equipment for the threat they actually face, and a mountain of vital business records has no protection at all.

When Is a Safe NOT a Safe?

There is confusion of terms in the use of fire and theft resisting equipment. This confusion in terms leads many users to believe that they have more protection than they really have. It is natural for customers who have a "safe" to believe that anything they put into it will be "safe."Our job is to be sure that our customer recognizes the type of protection they are getting with the equipment they purchase.

Four broad categories cover most of what people call a "safe," and each one is built to stop a different threat.

---

---

This is a FIRE safe.

It gives FIRE protection and is engineered and insulated to protect its contents against HEAT. It is NOT designed to keep out an experienced burglar.

---

 

 

This is a BURGLARY RESISTANTsafe.

It is engineered and constructed to protect cash and valuables against experience burglars. It gives little protection against heat.

 

---

 

 

This is a COMBINATION (COMPOSITE) safe

It gives both burglary and fire protection. The outer material is metal and the inner layer is a special composite material that provides both burglary and fire resistance.

 

---

This is an INSULATED VAULT door.

It gives similar protection to that of a fire safe. How much burglary resistance you get depends on the specific door: many insulated vault doors are built mainly for fire and offer limited burglary protection, while others carry a UL burglary rating.

 

VAULTS

Underwriters Laboratories assigns one of four ratings to vault doors and modular vault panels based on expert burglary attack with cutting torches, fluxing rods, portable electric power tools, portable hydraulic tools, and common mechanical tools for a set period of time. UL labels are mounted on the vault door and on individual modular vault panels. When the ratings for the door and the panels differ, a vault is, in practice, only as strong as its lowest-rated component. UL-rated vault doors and modular panels are usually specified by businesses, financial institutions, and government facilities that need a high rating; they are far less common in residential settings.

The ratings are:

Class	Attack time
M	15 minutes attack time
I	30 minutes attack time
II	60 minutes attack time
III	120 minutes attack time

Vault construction

Vault doors that are not UL-listed are evaluated based on the construction and thickness of the steel incorporated in the door. For non-UL listed vaults or panels, construction of the vault floor, ceiling, and walls is evaluated in terms of their thickness, and construction (steel, masonry, cinder block, filled cinder block, or reinforced concrete). Vaults constructed of poured concrete with reinforcing rods must meet the standards of construction established byASTM International (formerly the American Society for Testing and Materials) to assure appropriate burglary resistant protection, but are not rated by UL.

Doors and vault construction that are not burglary resistant may be listed as fire resistant and containers with these components should be used for storage of records and other valuable papers. Vaults constructed with masonry block, brick, or steel are not typically acceptable for burglary protection, except when values are low and other burglary protection compensates for the deficiency.

When the electricity fails and phones are out, your safe or vault is your last defense against a burglar.

Portions of this page are adapted from mid-twentieth-century materials published by the National Stationery and Office Equipment Association, preserved here for their historical interest. Where that original text described practices or standards that have since changed, we have updated it to reflect current testing and construction.

 

Choosing the Right Safe for What You Store

At Safe & Vault Store, we have sold more than 150,000 safes, and the single most common mistake we see is buying for the wrong threat: a fire safe where a burglar was the real risk, or a burglary safe holding documents that a fire would destroy. If you are not sure which type fits your situation, our safe buying guides and FAQs walk you through fire ratings, burglary ratings, and lock choices, or you can call our team and tell us what you need to protect.