Storage forum: Do burned CDs and DVDs have a shelf life?

Last fall I took a class on photos and our instructor said that you should always store them on edge and any time you made a change in the system to make a new master and throw the older one away. He suggested replacing them every five years. Its a small thing to do and not worry about losing anything.

Your belief that CDs can last as long as LPs is, unfortunately, totally incorrect. Ever notice what happens to metal objects ? Over time they corrode or rust (i.e., oxidize ). This is a chemical reaction which is unavoidable, except if your CD is glass or gold (which does not oxidize). Most CDs are comprised of a thin aluminum layer on a thick plastic base. The aluminum oxidizes.

Yes, LPs will not have this problem. But ... CDs will *definitely* go bad -- just a matter of time and how much exposure to heat, water, air, and other substances which can accelerate oxidation. For example, CDs will go bad faster in the tropics than in Canada. (10-15 years)

I saw a TV show a few months ago and they showed that the factory CD's & DVD's are pressed like a record. They make a steel master containing the pits and bumps and press it into a blank disk

Thank you, AnthonyNYC. Now, I know why I have not had a single, not ONE, pressed commercial CD fail on me in the 26 years I have had CD's! However, many burned CD's and DVD's have failed quite frequently. Nowadays, I use Fuji (probably one of the top brands) to back up, create at least 3 copies of each for redundancy, and keep a final backup on hard drives. Works for me!

Though some last longer than others, they will become unreadable to Windows. Especially RWs which you have erased and rewritten and added to a number of times.

There is software to read these CDs and DVDs when Windows will not, and you can usually rescue the material on the discs.

I recommend Isobuster (free for this purpose), which has been able to recover most of and usually all the material by going over and over the material in damaged sectors.
(I first learned of this from someone in Support at Nero, though the company now has its own disk rescue product, which I haven't tested.)

http://www.isobuster.com/

Also useful for damaged audio CDs is EAC (Exact Audio Copier; also free):

http://www.exactaudiocopy.de/

It's also good for undamaged audio, but more time consuming than CDex.


I'd advise making certain your material is readable every year or two, and consider using a dedicated external hard drive as an alternate backup.

This subject has been dealt with at length previously, in fact I wrote a response to a similar question in 2006 that "won" that weeks response award (it was the 1/27/2006 column, if you want to look it up).

In a nutshell: You are PROBABLY being paranoid.

The best information available (and it's definitely somewhat limited since CD-R has only existed now for 14 years or so) is that QUALITY optical media burned on a quality PROPERLY WORKING drive, will last at least 50 years and some estimates go out to 300 years, based on the best avaialble lab work and analysis (it goes without saying that no one has been able to test even 50 years in real world conditions).

Now, however, a bunch of caveats:

1. Media: There is good media and there is junk media. And there are dozens of different dye formulations in at least five major dye families (if you care, they are Cyanine, PhthaloCyanine, Metallized Azo, Advanced PhthaloCyanine and Formazan). These all have significantly different characteristics (they WILL have different lifes), and each of them can be made into a "quality" or a "junk" media of that type. I guess it goes without saying that junk media, of any type, is just that .... junk.

2. Drives: There are good drives, there are bad drives and there are good drives that have become defective. It is my personal opinion that a lot of the problems that we have are caused by drives whose laser output power levels are below spec. That can happen even to a high quality drive that was once good (it can also happen simply because the optics have become dirty). So the media isn't heated to the proper temperature, the dye doesn't fully change it's reflectivity and you get a burn that consequently has poor long term stability. So the moral of this story is that everyone who has an optical burner should have a laser power meter and use it regularly (just kidding .....).

3. Storage and handling: This, too, effects life. Temperature, humidity, handling, storage type (it's better to store discs vertically; DVDs should not be flexed (including as in removing them from a case), scratches can do obvious damage, etc. etc.

So you put all of those factors together and they all impact the life of your media. The estimates of 50 to 300 years were for quality media properly burned and properly stored. There is no absolute guarantee that any of us real world users will meet any of those critera much less all 3.

So what is the bottom line? Here is my conclusion:

All indications are that properly burned optical media will last for decades.

However, as all kinds of backups do fail, I ***ALWAYS*** have multiple backups. And I think that is one rule that applies for all backups of all types. One backup, even two, is NOT enough.

***NEVER*** use "RW" media (CD or DVD) of any type for anything that you plan to keep. Only use "R" media. Sorry, RW media just is NOT stable, I've had too many bad experiences with it in my 40+ years in the computer industry (only 10+ dealing with optical media, but that's enough for me .... I've seen a years long clear pattern emerge).

After using a drive for a while, and after using media that it has burned in other computers with other drives, you will get a sense of whether or not the drive is reliable. Pay attention to that; signs of unreliable operation (especially problems reading discs later, either in the same drive or other drives) should not be ignored. FWIW, I've had the best luck with Samsung (now TSST) and Pioneer and, frankly, much worse luck with almost all other drive brands (and I build and service computers, and this is based on hundreds of drives that I've dealt with).

Also, you mentioned "shelf life" in your query, that really would refer to the time BEFORE the media was burned, the time between when you bought the media (really, when it was made) and when you burned it (the time subsequent to burning would be the "archival life"). Shelf life is limited, optical media should be used with 5 years of it's date of manufacture, although in general we have no way of knowing when the media was made, but usually it will have been bought within a few months of manufacture.

Hope that this helps,
Barry Watzman

> (how can you distinguish top quality from mediocre?)

Buy name-brand CDs and DVDs. Those'll be top quality or close enough. Don't buy cheap. You get what you spend for.

Re: "I have had plenty of name brand CD's go bad, especially from Memorex."

Memorex is NOT a "quality brand".

It's tough, because the "brand" is often not the manufacturer, and most "Brands" are selling discs supplied by multiple manufacturers. But Memorex is a brand that I actually avoid. Verbatim is a brand that is generally well regarded, although much if not all of their media is made for them by other firms. Taio Yuden is usually recognized as one of the higher quality manufacturers (they do supply Verbatim, among others), but they are a manufacturer and not a brand.

By the way, one comment that I should have included in my original post but forgot ... limit your burning speeds to about 32x or a bit slower (but not absurdly slow) for CD and 8x or less for DVD (and, of course, always the slower of the rated speeds for the drive and media). Extremely high speeds accentuate whatever problems the drive and/or media may have.

Flash drives are NOT a backup device, they are a transport device (like RW optical media, which I generally hate).

> "Buy name-brand CDs and DVDs. Those'll be top quality or close enough. Don't buy cheap. You get what you spend for."

Pfffft! Unfortunately, brand name don't really mean squat nowadays, too many "brand names" sell lower quality crap these days, and if anyone wants to insist you get what you pay for, I'm certain you will get a flood of replies from others who can give you specific examples of their expensive purchases that turned out to be rubbish even though they were paying more for supposed better quality.

Often difficult to know these days... any purchase I'm to make where I want to make absolutely certain I'm buying the best, I do many, many, many searches and read many reviews/ratings etc and customer opinions from many a different site (to try and defeat biased or faked ratings). This usually works.

Re: "I cannot vouch for "quality" of media or "quality" or condition of CD drive, but I have had pictures, saved documents, and data(OS back ups) disappear from CD's in LESS that 5 years!!!!!"

You have a problem. Seriously, you do. I don't know if it's your media, your drive or something you are doing (again, DO NOT USE RW MEDIA FOR ***ANYTHING*** YOU WANT TO SAVE), but something is wrong. I am in the computer industry, I was a beta tester for Adaptec right after they bought "Easy CD" from Corel thru when they spun off their software division as "Roxio", and I have been using CD-R since 1994, thousands of discs (perhaps over 10,000). And the number I have burned that have later turned out to be bad for no explainable reason is in the low double digits (out of, again, thousands). And I am coming up on 15 "real" years now, I have 1994 to 1996 CDs and they are still just fine. Not some of them, but pretty much ALL of them (there are some I've never gone back to, but the point is that when I do go back ... and I do ... THEY WORK.

Most of us have read the articles on this and CD-R and DVD+-R are rated as 5 years. I think you are confusing home burnt media with pressed media that you buy in a store. The articles I read say 5 years and many of us don't get even that much. At home, you are only hitting the disk with laser so that you are making dark spots on INK. Not on metal.

I'm by no means an expert just a casual guy...but I will share my experiences with CDs. I was in high school in the late 90s (now over a decade ago) and got my first CD burner, burning at something like 8X!! Lol.

Anyway, the CDs I burned back then on Memorex and TDK, etc had been lying around with no cases, just in a big pile in my grandfather's garage for around 10 years, until a few months ago. I live in Alabama, very humid and this is not an air conditioned garage. I went through the box of a hundred or so CDs a while back and damn near 90% of them were good. Yes, after 10 years of lying in humidity and heat...the old burned CDs played fine. I ripped them all onto my itunes, of course.

I think some people tend to worry too much about this sort of thing. When you think about it, old video games from the 70's are working fine and the carts are holding the data over 30 years later. This was well before the technology had been refined. It's more uncommon to find an old Atari 2600 that DOESN'T work than to find one in good playing condition. What about the old Nintendo games? They still work and millions still play them daily...they've held up.

I own a Sega CD game console. These were made in the earl 90s, 1991 or 1992 and my factory made CD games from almost 20 years ago still look and play great. No rot. And it's not just me, plenty of people's CDs do.

I think it's like anything else...take good care of them and use common sense and CDs will last you.

Game console cartridges and factory CDs have absolutely nothing in common with home-burned CDs and DVDs, obviously. Thus, it's not relevant to bring them into your comparison, since they aren't made in a comparable way. Thanks for your post, though.

OK Barry,
Your answer was fantastic and Its helped to me a lot to understand why it happens so frecuently,
Thanks for your help
Miguel from Chile