In a past post about Switching storage format, a commenter expressed the worries regarding DVDs longevity. Those same concerns were sounded a few years after the CD format became popular. Since both technologies are dye based there is some room for concern.

Basically, the expected longevity of dye-based DVD-R and DVD+R is anywhere from 20 to 250 years, the same as CD-R discs. Some dye formulations such as phthalocyanine and azo last longer, more than a 100 years compared to 15 to 40 years for less stable dyes. Re-writeable DVD formats like DVD-RAM, DVD-RW, and DVD+RW, which use metallic materials that change the phase of the light, rather than light-sensitive dyes, have an expected lifetime of anywhere between 25 to 100 years. It’s important to remember that the quality of materials and production process can greatly affect the longevity of DVDs. Poor quality DVDs may deteriorate within a few years and produce errors or become unreadable within a year time.

There is no big difference between DVDs and CDs when it comes to materials. The dye chemicals used in write-once DVDs are similar to CD-R, though recording density and disk construction differ. So you are taking no greater risk when using DVDs instead of the old CDs.

When talking about “short” lifespan of optical media we need to take look at the alternatives as well: Magnetic media like tapes and diskettes last 10 to 30 years, acid-neutral paper can last about 100 years or longer, high quality microfilm is believed to last about 300 years or more. So it’s obvious to see that CDs and DVDs alike have a relative long lifespan compared to other possible storage methods. It’s also important to remember that digital storage media often becomes obsolete within 20 years, long before it physically deteriorates.