CDs and DVDs seem permanent, but they don't last forever. Yet things we do to them makes a difference to their life. One should never use a pen, pencil or hard-tip marker to write on 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.
Digital Data Preservation Program CD and DVD Archiving Quick Reference Guide for Care and Handling
- Handle discs by the outer edge or the center hole.
- Use a non solvent-based felt-tip permanent marker to mark the label side of the disc.
- Keep dirt or other foreign matter from the disc.
- Store discs upright (book style) in plastic cases specified for CDs and DVDs.
- Return discs to storage cases immediately after use.
- Leave discs in their packaging (or cases) to minimize the effects of environmental changes.
- Open a recordable disc package only when you are ready to record data on that disc.
- Store in a cool, dry, dark environment in which the air is clean.
- Remove dirt, foreign material, fingerprints, smudges, and liquids by wiping with a clean cotton fabric in a straight line from the center of the disc toward the outer edge.
- Use CD/DVD cleaning detergent, isopropyl alcohol or methanol to remove stubborn dirt or material.
- Check the disc surface before recording.
- Touch the surface of the disc.
- Bend the disc
- Use adhesive labels.
- Store discs horizontally for a long time (years).
- Open a recordable optical disc package if you are not ready to record.
- Expose discs to extreme heat or high humidity.
- Expose discs to extreme rapid temperature or humidity changes.
- Expose recordable discs to prolonged sunlight or other sources of UV light.
- Write or mark in the data area of the disc (area where the laser "reads").
- Clean in a circular direction around the disc.
For CDs especially do not:
- Scratch the label side of a CD.
- Use a pen, pencil, or fine tip marker to write on the disc.
- Write on the disc with markers that contain solvents.
- Try to peel off or re-position a label.