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Will my backup hard drive stored in my safe survive the heat of a fire?


Do you know what the maximum temperature is that an external hard drive can
withstand? (not at which it operates, but an external temperature it can

I bought an external hard drive with the intention of backing up my data
once a week and storing the hard drive in a fire safe for the remainder of the
time in case of fire. I was reading through the manual for my safe the other
day, and it said it protects the contents by making sure the interior doesn’t
raise to above 350 degrees in case of fire. This got me thinking: the papers I
have in there would be ok at that temperature, but would my credit cards and
backup hard drive be ok? Wouldn’t they melt? I read over the hard drive manual
and even called the support number, but no one could give me the maximum
temperature that the external hard drive could withstand. The only temperature
numbers I could get were its operating temperatures.

I’ll be honest – I don’t know the answer to your specific question. I’ll
make an extremely uneducated guess, and maybe some readers will comment with
better information.


I, personally, would never do what you’re suggesting. But the good news is
that you’re 80% of the way to what I do, in fact, do.

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First, I’m not surprised that you can’t get a straight answer from the
manufacturer – if they don’t publish the information already, I’m certain it’s
not something that they would want to be held accountable for.

My totally wild guess – that you may not hold me
to – is that your drive might be OK at 350 degrees. Now, “OK” is a
relative term. I’m envisioning the drive itself being ok, but the case, the
cables and everything else melted into a plastic puddle. You might be able to
retrieve your data, but it won’t be a pretty process.

I’m also expecting that your credit cards will part of the plastic puddle.
(Though they’re easier to test – take one of the cards you get in your junk
mail every so often, and bake in a 350 degree oven for, oh, half an hour or so
and see what’s left. Just make sure you put it on something disposable.)

“While I do have a safe in my home, I do not rely on it
for anything related to my computer.”

Now, why do I think this is such a bad idea?

Well, besides the fact that I’m not certain that the drive would actually
survive the heat, I’m fairly certain that other damage could be worse. I
vaguely recall that most property damage resulting from a fire is,
paradoxically, water damage. What happens if your safe gets flooded? Paper can,
in many cases, be dried out. Yes, hard drives can as well – but again, you’re
pushing the envelope, and it may be a difficult recovery.

And of course the safe
may be buried for days in the rubble of a true catastrophe.

While I do have a safe in my home, I do not rely on it for anything related
to my computer.

What I do rely on, is off-site storage.

My personal situation is fairly simple: I have two physical locations, say
home and work, and at each location is an external hard drive to which data is
being backed up nightly. Every so often I swap them, simple as that. That way each
location has off-site backup at the other. If either location is destroyed, the
other remains.

A more common scenario is to simply take your hard drive (or backup CD’s, as
I used to) to the home of a friend or family member.

Depending on how much data you’re talking about, this might also be a good
use for some of the on-line storage that your ISP or other service providers
might give you for free.

But if you’re going through the trouble of creating and updating that backup
disk, I really recommend taking that next step and storing it (or a copy of it)
off-site, somewhere.

Do this

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14 comments on “Will my backup hard drive stored in my safe survive the heat of a fire?”

  1. A friend of mine, who parks on the street, keeps his backup cds in the trunk of his car. Worked pretty well until our recent heatwave.

  2. Hi Leo: Couldn’t a harddrive be put in a large safety deposit box in a bank, the chance even if a fire broke out in a bank that area of the bank has nothing to burn around it in that large vault? Just a suggestion, Regards, Tom

  3. I’ve generally heard that hard drives don’t survive a fire even when in a fire safe, but it may really be more they don’t survive such that you can just plug it back in and use it. PC Magazine put one of the hard drive recovery services to the test by dropping a hard drive in a camp fire for the evening and then sending it to them and they were able to get all the data off — so, it may cost you a lot, but the the data may be recoverable. See:,1759,1911131,00.asp

    That said, I think Leo’s recommendation to use a trustable offsite location is the best.

  4. They won’t survive! Well, there’s a very good chance they won’t. It’s not melting you need to worry about, so much as the Curie Temperature. It’s the temperature, for a given (ferro)magnetic material, above which it is no longer magnetic. If the temperature of the platters inside your hard drive rises above their Curie Temperature, ALL your data is gone IRREVERSIBLY. (The camp fire case above must not have exceeded the Curie temp)

    I don’t know the Curie temperature for the materials used in hard drives, but I’ve found suggestions they might be quite low. So you’d need a safe capable of keeping the internal temperature below 100 C, maybe even lower.

  5. TW is correct. I hadn’t realized the Curie Point for typical HD platters was so low. A typical fire safe won’t keep temperatures that low for any significant period of time.

  6. TW: Where did you get the 100C for the curie temp? Most materials’ curie point is much higher than that?

    There are also different classes of fire safes; you can get a standard one (which allows the internal temp to get to 350), or you can get a data-rated one (I forget the temp, but “supposedly” you can keep tapes in it).

    That said, there’s nothing like an off site backup (especially if the site is condemned and they won’t get it for you until the investigation is over)…

    Depending on how much you trust the keeper, it might be a good idea to encrypt the data… Might be becuase if there’s an error in the data, it will scramble a whole block of data (2K? depends on the algorithm) instead of a couple of bytes… which, depending on the backup type and compression may *really* make the data hard to get at.

  7. Ratings for safes use both time and temperature, and many, if not most, small home safes are under 15 minutes. Another rating is how long the safe will resist drilling or other burglary attempts.

    Look for a UL rating. A Class B safe should resist a 1700 degree (F) fire for 30 minutes with the interior space not exceeding 350 degrees. Approximate size for such would be 4’x2’x2′ and 700 pounds for around $2,000.

    As previously mentioned, there are better and cheaper alternatives for data backup than home safes.

  8. Dear Sir/Madam,
    I have a MAXTOR ONE TOUCH III USB 2.0 it does not seem to work well or work at all with my Microsoft Windows Server 2003 Standard Edition. What must I do? Please help!!!?


  9. The safe you need for data storage is a the Fireking Media Vault (see:,”>,”>, which has a one hour UL rating that ensures the interior is kept under 125F and humidity under 80% in a 1700F inferno – this will keep ANY digital media in tip-top shape after even the worst house fire (about 1200F). It’s a stand-alone unit – but not sure how much it retails for.

    Otherwise, if you already have a fire safe (with, say the standard UL 350F rating to preserve paper) you can get something like the Schwab Media Cooler ( which, when inserted in the safe, will do the job of the aforementioned fireking product.

    For my own data, I use this second option. If I have a fire I’ll let you guys know how it goes.



  10. Most fire safes are designed to keep the contents below the flammable temp of paper. But most fire safe mfrs also now make specific media safes that are designed to keep the contents at or below a max temp of 125 degrees F and 80percent humidity for 1 to 3 hrs depending on the model. As for whether this is safe for hard drives, I checked the Western Digital website and they list the max temp as 149 degrees F while not powered up. So I think the media fire safe would be an OK choice for protecting hard drives on site.

  11. Hi, I am making backup to an external harddrive but found when forced to restore the backup it did not work, lots of error messages etc. NOW I would like to take another rout – I want to mirror image the C drive but also want to mirror image the D drive. Is it possible to mirror image 2 drives to one drive and for the mirror drive to stay updated with the new data placed on the C and D drives? If so, what software will be able to do this?

  12. Dear Leo,

    In 2007 while returning from youth camp while driving home and 6 hours from home, received the shocking news our house had caught fire and the fire trucks were on their way to put out the fire. Six hours later when we arrived, in the middle of monsoons (Thailand) we discovered that our entire second floor was nearly totally consumed by the fire. My wife’s office was next to the worst part of the fire and everything was charred and burnt in the room. Her desktop computer and monitor were just globs of plastic, melted down from the intense heat. The burnt out, now open, ceilings allowed not only the water used to put out the fire, but also inches of monsoon rains that soaked everything. I could not even enter the building for a whole day, since we arrived at night leaving the computer exposed to even more damaging elements.
    During the recovery, I placed the computer case, in the garage though I doubted it would contain anything useful. A full month went by and Gail was missing some of her data. So I unscrewed the case screws, and removed the hard disk which looked surprisingly good coming out of the damaged computer case.

    Low and behold! The data survived and the hard disk worked enough for me to copy her data off to her delight. Later on I was assembling a student computer, and thought, “Oh why not?!” and grabbed that old hard disk and found out that it would work after that and it did for years later. In fact, even the motherboard and power supply were recoverable later on. Though the power socket was deformed by the heat and had to be replaced. Hope this may give one of your readers a little hope that fire, water and even the monsoons could not stop that computer.

    Kind regards and thank you for your great articles, which I read regularly.

    Donald Craft


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