"Andrew Gabriel" wrote in
message

Is it safe to store audio CDs in a loft which regularly
hits 45C in the summer, or is that going to cause them to
deteriorate? These are standard mass produced ones, not
home written in a
CD writer.

IME the most temperature-sensitive portion of a CD is the lacquer top layer
with the graphics and nomenclature on it. I've seen a goodly number of CDs
that were damaged by direct sunlight and/or heat, and the lacquer coating is
what seems to get damaged first and damaged the worst. Damage to the lacquer
layer can cause damage to the aluminum layer, which is of course quite
critical.

Interestingly enough, much of the lore and technology of storing lacquer
relates to LPs, which are usually cut on lacquer-coated discs of aluminum at
one point in the production process. Often these intermediates in the
standard production process are the only extant form of legacy recordings.

Another critical application of lacquer coatings is furniture and art works.
The lore and technology of storing fine furniture and art applies.

Interested parties should of course do their own research. My take on what
I've read is that temperatures of 45C should not be a problem, but that
control of the rate of change of temperature, and humidity should be
carefully controlled.