Gold logo icon

Get a free call from our experts!


Safe fire ratings importance

Notes like “UL”, “JIS”, “30 min” for the new safe you’re checking might be not helpful at all if you have no clue what they mean. Let’s make all these safe fire ratings clear so you will be able to choose the safe perfect for you. Sure Lock & Key is always here to help whenever you need professional advice or safe installation itself!

What are safe fire ratings?

Thanks to Ray Bradberry, we all know that paper combusts at 450°F. So there has to be a safe that can maintain the temperature significantly below 450°F to make the assets inside last longer. Generally speaking, a safe fire rating is the rating that specifies how long the temperature inside the safe will stay below a certain temperature. Safe fire rating contains a few dimensions. It is based on the manufacturer certification, the test results of how long a safe can survive external temperature, how long it can stay below 350°F, and whether it will survive a fall if the floor collapses due to fire. Let’s discuss all of these in detail.


UL - Underwriter Laboratories

This is a universal, Gold Standard of rating systems. If you’ve bought a safe and it has a UL Fire rating, you can be sure that your safe was tested in all the possible ways to be recognized as highly durable.

UL 72 - is a set of special tests to prove that the safe can remain at the needed temperature for a certain amount of time. Naturally, depending on the type of content you’re going to keep inside, you need to buy a safe with the needed fire rating. UL “Class 350°F - X Hr” fire-rated safes are the most common types. They are designed to maintain the temperature below 350°F to protect paper documents. The X means the number of hours it can remain at the mentioned temperature being left in the fire. There also are safes rated “UL Class 150°F - X Hr” and even “UL Class 125°F - X Hr”. They are designed to safeguard more gentle assets than paper documents such as computer disks and floppy discs. Since the last two types of safes usually are used to store data and media, they also have a humidity rating.

As you can see, you can get a safe depending on your needs.

UL tests for safes

Fire rating attribution isn’t as easy as you might think. The Underwriters Laboratory applies a wide range of tests to figure out whether a safe can resist the explosion, extreme temperature, building collapse, etc. But in the end, we have the information we can totally rely on when choosing a safe.

To better understand why the UL classification of fireproof safes is so important, let’s check how exactly the special tests are conducted.


Safe’s fire endurance test

This test safe is evenly equipped with heat sensors and paper. Then the safe is put into the furnace where the temperature rises to the needed rating. Needless to say that a safe has to maintain the needed temperature for the amount of time required for a certain rating.

Safe’s explosion Hazard test

The safe is placed in the furnace set to 2000°F. It has to remain inside for a specific amount of time. For example, if we test a 1-hour fire rating safe, it would be inside for 30 minutes, etc. If the safe has survived such extreme temperature, it stays inside the furnace to cool, and then it’s examined for usability.

Safe’s fire impact test


This test has three stages. First of all, the safe has to be heated in the furnace for a certain amount of time which depends on the classification being checked. Then the heated safe is dropped 30 feet onto concrete and bricks. The final stage is to put the safe back into the furnace for another 20-60 minutes. That’s the most brutal test, but there’s no other way to check whether a safe can survive falling from a height in case of fire.

Other rating systems

The UL testing is pretty expensive. It may cost more than $50 000. So, not all manufacturers can afford such testing for each safe model. That’s why such manufacturers create their own rating systems or hire another company to test their safe ratings.

Nowadays, lots of safes are manufactured in Asia. These manufacturers use the KIS fire rating which stands for Korea Industrial Standards rating. Another popular rating is JIS Safe Fire Rating which stands for Japan Industrial Standards rating. All of this rating includes testing similar to UL’s testing. Also, some manufacturers have their own rating system. But it’s totally up to you whether you want to get safe with the UL rating system or any other. Safe installation is a process that requires lots of knowledge and professionalism, so the safe purchase is only the first step. You also need to find a locksmith who can provide you with the service itself and with the required information.

(855) 909-4011

phone icon

Call Now

phone 24/7

Request A Callback



Call Me Back

Why choose us?

Sure Lock & Key as one of the best-rated locksmith companies, aims to provide customers with the most professional house, car, and commercial locksmith services at honest prices. Having 35 years of experience in the industry, we always aim to be your best locksmith partner. Rely on us and make sure that we are the best.


Fair pricing policy


A team of professionals


Our 24/7 customer care team


An individualzed approach

you may also like