Ask the Archivist columnist Sally Jacobs discusses the lifespan of compact discs.
Q. I had a scanning service transfer our old slides to CD. Now my son-in-law says these photos are doomed because the discs will rot in a few years. Is that true? I thought CDs were supposed to last forever.
No one can say for sure when your CDs will fail—longevity estimates range from three years to several centuries. But you face three major dangers:
- Failure: “CD rot” is an unscientific term that describes what happens when the dye layer of a CD disappears. Research has shown that inexpensive CDs are more prone to failure than quality ones.
- Damage: Scratches on either side of a disc can destroy your data. Even something as simple as pulling a CD out of a sleeve can cause nicks and scrapes.
- Obsolescence: Let’s imagine for a moment that your CDs actually will last for centuries and never become scratched or damaged. Do you really believe your descendants will have CD readers 100 years from now?
When buying recordable CDs, choose a brand that uses phthalocyanine dye, such as Mitsui Gold
. Are these guaranteed to last forever? No, but you can be certain you’re getting a quality product.
If you’re scanning a large collection of old photographs, I recommend storing them on an external hard drive and/or with an online backup service. Burn one set of CDs as backup, and extras to share with relatives. Remember the acronym LOCKSS: Lots Of Copies Keeps Stuff Safe.