Vaults—especially bank vaults—are designed to be airtight and not a structure where humans are expected to stay for extended periods of time. On a recent visit to a safe deposit vault at a bank, I found myself alone while putting away my valuables. I wondered how long I could survive in a bank vault if trapped in one? What I found surprised me.

You may survive about 17 hours or more if you are inadvertently trapped in a vault or any large airtight room. But it is unlikely you will survive more than 72 hours. This means if you are locked in a bank vault over a 3-day weekend, for example, when the bank is closed for business, you will likely not survive. The actual time you survive depends on a variety of factors. 

Let’s look at what increases your chances of survival and what you could do if trapped. Surviving in a bank vault is similar to surviving an extended period in an airtight space. 

Key Factors When Trapped

• Dehydration and thirst—vaults are designed to be low humidity to keep valuables and documents in good condition. Banks often have ventilation to keep temperature and humidity levels low.
  
  
• Suffocation—because air-tight or restricted air ventilation can result in dangerously high levels of carbon dioxide that can kill you. Lack of oxygen, which is at a higher concentration than carbon dioxide, is often less of a factor.
  
  

Humans can live for three weeks without food but only 2 to 3 days without water. A lack of food, though uncomfortable, should be the least of your concerns. Obviously, your particular circumstances, like critical daily medication, can also be a factor.

3 Things to Do If You Are Trapped in a Vault

• Focus on being found rather than trying to get out. The most urgent issue is to alert someone as soon as possible. After all, whoever lets you in is your best bet to let you out. Search for emergency features to alert others that you are trapped: emergency release switches or buttons, intercoms or landline phones, fire alarms, hidden burglar alarms, etc. Try 911 on your cell phone, though it is likely you won’t get a connection or wifi in a vault.
  
  If you see a sprinkler system, see if you can activate it to set off an alarm. If you see a security camera, try turning it off to catch someone’s attention. If all fails, don’t even think of getting out: that’s for the movies. Vaults are secure, and you are unlikely to find an easy way out. 

• Control your breathing to reduce carbon dioxide levels in the vault. Knowing that a high level of carbon dioxide is your number one risk, conserve your energy and lower your breathing rate by reducing your activity level. This includes sleeping and reducing movement. Try not to panic, which will increase your breathing rate. If you are lucky, the ventilation in the vault might keep you alive for a long time. Carbon dioxide concentration is about 0.036% in air and toxic at 10%, which leads to convulsions and death. Carbon dioxide is also 1.5 times heavier than air, so climbing up to a high point in the room may help.

• Dehydration and thirst are your enemies. The low humidity causes dehydration and makes you thirsty. If there is no sprinkler system, conserving your energy reduces thirst and increases your chance of surviving at least 2-3 days. Your obvious thought might be to look for other water sources—like you! But drinking your pee can kill you. As the Army Field Manual points out, drinking your pee (which is 95% water with high levels of sodium and other salts) is like drinking seawater (96.5% water) which will dehydrate you further.

Is an Inside Bank Vault Really Safe for Your Valuables?

We discussed personal safety; now, what about the obvious: are your possessions really safe in an inside back vault?

Some bank vaults are not as safe as they seem to be. In 2016, bank robbers broke into the bank vault and stole some of their customers' belongings. Robbers have also broken into bank vaults by picking locks of the bank's safe deposit boxes. These burglaries are becoming more common in America nowadays.

Another problem that bank customers now face is that they rent out safe deposit boxes that were active decades ago, and then these customers stop paying rent, making it easy for bank robbers to take what's inside those boxes.

How You Might Lose Your Valuables Even Without a Break-In

Bank vaults are supposed to be impenetrable, but bank robbers have been using the bank's keys to break into bank vaults. According to bank employees, they see someone coming in with a bank key and then leaving an hour later with a box full of money.

These bank robberies can happen in any country. The bank vault that once held the bank's money is found to have been broken into. The bank robbers stole the bank's money and other belongings, leaving the bank with nothing. The bank had no choice but to close because it was nearly bankrupt.

Safe deposit boxes are still a very secure place to store your most valuable items. But, as with almost everything else, it’s important to maintain oversight and to stay in contact with your provider.

Best Practices If You Have a Safe Deposit Box

To reduce the odds of such mishaps, please maintain a good relationship with your bank branch manager and open your box from time to time so personnel at your bank know who you are. Also, consider using online bank vaults instead of bank vaults for storing your belongings.

Also, customers who change bank accounts or relocate should take their belongings with them so it is easier to secure personal belongings in bank vaults. Safe deposit boxes are still a great way to store valuable items, but bank customers have to be more aware of bank robberies.

Another solution is to make bank-safe deposit boxes more secure by using bank safes or bank security deposit boxes instead of bank vaults.

Safe Deposit Box Alternatives

If you want quick access and find a safe deposit box at a bank too small, inconvenient, and unnecessary, check out our home safes. In particular, review the TL-15 and TL-30 safes that come closer to matching the burglary protection that you expect with inside bank vault security.

Bank Vault Doors for Sale | Really?

Yes, you can even buy a bank vault door for no other reason than to impress your friends. Of course, you’ll pay a pretty penny, but if security and vanity are your thing, why hold back? If you are serious, though, there are obviously companies who would be happy to outfit your mansion to protect your fortune.

Conclusion

You can survive being locked in a vault if you act quickly and focus on being found rather than trying to get out. The first few minutes are likely to be crucial as someone is likely to be around after having let you into the vault. If you are stranded and locked in, your best bet is to stay calm, conserve energy, and focus on surviving by reducing your breathing rate and combating thirst. Do this, and you may survive for 17 hours or more.

If you are looking to create your own vault safely, check out our selection of Vault Doors and High-Security Doors that can turn a room into a walk-in safe.