Researchers offer tips for longer lived CD, DVDs

You should never use a pen, pencil or hard-tip marker to write on your CDs

That is among several recommendations made by computer scientists at the National Institute of Standards and Technology (NIST), who sliced, diced and baked CDs and DVDs to see how long the digital information would survive.

Most CDs and DVDs will last 30 years or more if handled with care, but many factors can slash their longevity. Direct exposure to sunlight can do a great deal of damage both from the sun’s ultraviolet rays and the heat. Indeed, any rapid significant change in temperature or humidity can stress the materials. The study also found that fingerprints and smudges frequently do more harm than scratches, and recommends handling discs by the outer edge or the center hole.

Discs may be cleaned with a cotton cloth by wiping in a straight line from the center of the disc toward the outer edge. Isopropyl alcohol may be used for extra cleaning power.

Discs last longest when stored in plastic cases in a cool, dark, dry environment. Because gravity can gradually bend the disc, storing it upright like a book is best for long-term storage.

Many libraries, archives and government agencies store information on optical media, and NIST collaborated with the Council on Library and Information Resources to issue the research report.

A quick reference guide to the research group’s findings is available at www.itl.nist.gov/div895/carefordisc/disccare.html.