From NIST:
One method for determining end of life for a disc is based on
the number of errors on a disc before the error correction occurs. The
chance of disc failure increases with the number of errors, but it is
impossible to define the number of errors in a disc that will absolute-
ly cause a performance problem (minor or catastrophic) because it
depends on the number of errors left, after error correction, and their
distribution within the data. When the number of errors (before error
correction) on a disc increases to a certain level, the chance of disc
failure, even if small, can be deemed unacceptable and thus signal
the disc’s end of life.
Manufacturers tend to use this premise to estimate media lon-
gevity. They test discs by using accelerated aging methodologies
with controlled extreme temperature and humidity influences over
a relatively short period of time. However, it is not always clear how
a manufacturer interprets its measurements for determining a disc’s
end of life. Among the manufacturers that have done testing, there
is consensus that, under recommended storage conditions, CD-R,
DVD-R, and DVD+R discs should have a life expectancy of 100 to
200 years or more; CD-RW, DVD-RW, DVD+RW, and DVD-RAM
discs should have a life expectancy of 25 years or more. Little infor-
mation is available for CD-ROM and DVD-ROM discs (including
audio and video), resulting in an increased level of uncertainty for
their life expectancy. Expectations vary from 20 to 100 years for these
discs.
https://nvlpubs.nist.gov/nistpubs/legacy/sp/NISTspecialpubli...