Optical disc shattering linked to cleaning chemicals and foam storage

CD Shattering Incidents Reported

Optical disc collectors have observed catastrophic failures in compact discs, with some CDs splitting or shattering. This phenomenon is linked to the degradation of the polycarbonate substrate, a key component of CD construction.

Chemicals and Foam Identified as Causes

Two primary causes for this degradation have been identified: cleaning substances and off-gassing from foam padding in storage cases. One instance involved a CD that reportedly cracked after being cleaned and polished, suggesting chemical cracking from cleaning agents. Another case showed severe damage to a CD stored in a foam-padded case, where off-gassing ammonia compounds from the foam are believed to have weakened the polycarbonate structure.

Polycarbonate Vulnerability in CDs

Compact discs are particularly vulnerable because they rely on a single layer of polycarbonate. In contrast, DVDs use two polycarbonate halves bonded together, which makes them more resistant to these specific types of chemical degradation. The off-gassing from certain foam types, especially polyurethane, can create vapors that lead to crazing or cracking when sealed with CDs.

Broader Data Preservation Concerns

These new findings add to existing data preservation challenges for optical media, such as bit rot and laser rot. These issues are typically caused by oxidation of the reflective layer, contaminants, and UV light damage. The ongoing discovery of new degradation mechanisms underscores the importance of backing up data stored on optical discs to ensure long-term preservation.