This question doesn’t come up very often, but has a time or two, so let’s try and summarize this a bit and come to an general answer.

In the early ‘90s when the first CD-R disc was introduced manufacturers said the media had a data life in excess of 40 years. In the late 90s when the first DVDR discs appeared on the scene producers proclaimed a data life of at least 100 years. Throughout that time and even today the press will “discover” that the media is susceptible to CD or DVD rot that will eat your information – audio, video or data – in as little as two years after it is written.

Since CD’s and DVD’s are used to archive nearly everything today, it does make you worry. Especially when these discs are the only place you have precious, irreplaceable family memories – photos and movies – as well as vital family, personal and company data/documents.

Most people who burn a disc without producing a coaster believe they have quality media. Unfortunately that only tells you the disc will be compatible (able to be played) in the vast majority of CD or DVD players. More importantly all better quality CD and DVD burners include technology called overburn/underburn protection making coaster production a thing of the past. The basic construction of the two technologies enable you to burn your data in a very precise, very controlled manner

There are only two foolproof ways of proving the data life of the discs you use:

Write a few CD or DVDRs, then wait about 25-50 years and check if they still hold the correct data

Use a CD/DVD analyzer that is specially designed to retrieve very accurate information about your media and your data after accelerated aging in test chambers where the discs are subjected to excessive temperature and humidity tests

The first is impractical. However, some of the first discs produced and written to in Japan still have the data intact. The second provides only theoretical limits and doesn’t take into consideration how you use, handle and store the media. However, assuming proper handling, chart D illustrates how temperature and humidity can affect the data life of quality media.

Between the CD-R discs produced in the early 80s to today’s double layer DVD+R discs and throughout the brief optical industry there has been considerable progress in write performance, capacity, quality and obviously price.

Following the test procedures of the International Standards Organization (ISO) quality media manufacturers have been able to document data life-spans ranging from 50-200 years. But keep in mind there are wide differences between low budget media operations and quality media firms. In addition variations in manufacturing methods, materials and processes/procedures can dramatically effect the data life of the media you use.

Believe it or not YOU are the greatest danger to the data longevity of your personal, family and business information that is stored on CD and DVD. Direct exposure to sunlight and intense heat can do dramatic damage. Rapid changes in temperature and humidity can stress the materials. Gravity can bend and stress the discs. Fingerprints and smudges can do more damage than scratches.

Simply by following a few Do’s and Don’ts you can ensure your precious family and friend pictures, movies, family records and business files have the maximum data life.

Do’s:
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 original jewel cases that are specified for CDs and DVDs
Return discs to their jewel cases immediately after use
Leave discs in their spindle or jewel case to minimize the effects of environmental changes
Remove the shrink wrap only when you are ready to record data on the 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
Check the disc surface before recording

Don’ts:
Touch the surface of the disc
Bend the disc
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.

In my opinion I believe that CD and DVD media should last up to 50 years.
To be safe I usually re-burn the data CD’s every two years and discard the old ones just to be fresh.