Life span of DVDs and other recordable media | Talk it up | Forums

DVD-R and CD-R "write-once" last longer than their respective -RW format write-many".

This is from an artical about archival for librarians (which may be more than you need), but to quote "RW [...] discs are generally not considered for long-term or
archival use"

http://www.clir.org/pubs/reports/pub121/sec4.html – Here's the full article which discusses the alloys and such used on the various disks.

Here's an article from PCWorld stating that burned CDs may only have a lifespan of 2 to 5 years.  I couldn't find a date on it though:  http://www.pcworld.com/article/124312/do_burned_cds_have_a_short_life_span.html

But here is another forum posts (seems knowledgeable) that suggests that high-quality, properly stored (temp, humidity, and no exposure to sunlight) media will last much longer:  http://forums.afterdawn.com/thread_view.cfm/708817

Google "DVD longevity" if you want to find more links.

Here is the link to the table of contents for the first link I posted above:  http://www.clir.org/pubs/reports/pub121/contents.html.  It is titled "Care and Handling of CDs and DVDs:  A Guide for Librarians and Archivists".

And here is some valuable advice from the archiving link above:

CD-R,
CD-RW, DVD-R, DVD+R, DVD-RW. DVD+RW, and DVD-RAM
discs can become unusable in a matter of days. If such a
disc is left in an environment that allows direct
sunlight
and extreme heat buildup (e.g., on the dashboard of a
car
in summertime, or next to a heater by a window), the
organic
dye or phase-changing film that holds the data will
degrade
quickly, causing the disc to become unreadable. A disc
is
not protected from the effects of heat buildup if left
in
a case that is exposed to direct sunlight or other
sources
of heat. Extreme heat buildup can also cause warping of
the
disc.

 
• The DVD-R/RW standard was developed by Pioneer, and is used primarily by Apple and Pioneer. These “minus“ discs can only be written to in one layer on the discs surface. In addition, this format is supported by the DVD forum, but is in no way an  industry standard. DVD-R/RW discs are cheaper than the “plus” format.
• The DVD+R/RW format is supported by Philips, Dell, Sony, HP, and Microsoft. These discs can be written to in multiple layers, giving them slightly better and more disc storage than the  “minus“ format. Because of this additional capacity, they are slightly more expensive than “minus“ discs.