Frequently Asked Questions About Compact Discs

Please contact Media Sciences if your questions are not answered on these pages.

Are CD and DVD discs reliable? I keep hearing about "CD Rot" and "Techno Rot" that imply media is unstable.

Do not believe everything that you hear or read. Media Sciences was interviewed by various news sources regarding this issue. Our consistent position is that CD and DVD discs are very robust, and are suitable for archival storage. The media have chosen to unnecessarily alarm users by quoting unusual examples of CD and DVD degradation. This may attract readers, but does not fairly represent CD and DVD quality.

Any product can fail if it is improperly manufactured, handled, or stored. Automobile tires are robust and can withstand potholes and other forms of abuse. However, tires produced with defective cords or belts can fail. Cut the sidewall by driving into a curb and the tire will fail at an inconvenient time. Disaster awaits if you drive at 80 mph with very low tire pressure.

Poor manufacturing process design or quality control can produce bad CD and DVD discs. Optical media can be molded or matallized improperly. The protective or bonding layer can be defective. Reactive inks can be used for a printed label. All of these have, and continue to be, observed. These require diligence by the purchasing organization, but do not invalidate the robust technology.

Early CD discs manufactured with a defective protective layer failed because the coating did not extend to the edge. The aluminum metal was exposed at the rim and reacted with the atmosphere, causing degradation and eventual failure. Although this was called "laser rot", it was related to neither the laser nor to rot. Yet this inappropriate term continues to be used today.

Exercise reasonable precautions. Record the discs in high quality drives. Handle discs only by the edges. Do not write on or abuse either surface, or apply adhesive labels. Store discs in jewel cases, not in envelopes, especially those with windows. Maintain temperature and humidity levels appropriate to an office environment. Regularly monitor archived media, and re-record if deterioration is noticed. Excellent longevity will result. Will it be 100 years? Probably not, but no one really knows. When compared to alternatives, it is apparent that CD and DVD media are a practical option for archiving.

Users cannot blindly assume that their media and drives are of high quality. Wide variations exist, and only comprehensive testing can validate quality. Test data, not opinions, provide confidence in successful interchange and longevity. These are proven capabilities of CD and DVD media, but require diligence if they are to be attained.