Q: It was my understanding that music fi les recorded on CD-R had a 100- year life expectancy based on laboratory studies. However, a recent study commissioned by the Library of Congress found that music fi les on CD-R last only 3 to 5 years before they start to fade. Does this mean that it’s necessary to re-record music CD-Rs every couple of years to preserve them?
Gary Johnson | Duluth, MN
A: Here’s what the Optical Storage Technology Association (OSTA), a trade group representing many of the big-name recordable-media manufacturers, has to say: “The life span of a written disc depends upon a number of factors, including such things as the intrinsic properties of the materials used in the disc’s construction, its manufactured quality, how well it is recorded, and its physical handing and storage. As a result, the life span of a recorded disc is extremely difficult to estimate reliably.” In other words, not even the OSTA knows how long your CD-Rs will last.
The key issue with CD-R lifespan is the condition of the organic dye layer embedded in the reflective side of the disc. This layer contains the recorded data, and when it begins to degrade, or “fade” — a process that can be accelerated by direct exposure to sunlight &mdash that data can become unreadable. In the years since CD-Rs were first introduced (in the late 1980s), disc manufacturers have introduced improved dye formulations that are less susceptible to fading, so the older your CD-R discs, the more in danger they may be.
With hard-drive storage costs nearing less than 10 cents per gigabyte, there’s no reason not to back up your treasured CD-Rs on a computer. If hard-drive failures have you spooked, you can also burn replacement CDs of your ripped CD-Rs. Basically, when it comes to old recordings you care about — be it a music CD-R or a videotape of your kid’s birthday party — the more backup options the better.
