Optical discs weren’t originally designed for storage, many discs which were produced in the early days are now close to expiration unless they are stored in an ideal environment. In order to find out what type of environment is most suitable for optical discs like CD and DVD, Library of Congress collects unwanted discs from different ages and manufacturers in attempt to what can damage discs:
- CD-R uses organic dye, which results shorter lifespan than commercial pressed CD.
- Most people will be very careful not to scrape the surface of recording side. In fact, the label side has less protection, the data is stored right under the thin layer of print label. The recording side actually has a thicker plastic layer for protection. Therefore, touching the surface of the label side may pose faster oxidation.
- Writing on the label side with a marker can also accelerate the deterioration.
- There are still some unknown factors. There are cases of two CDs which are manufactured at a same year, one was completely destroyed and the other had no damage at all after testing.
- DVD poses higher risks than CD due to the higher data density.