CD, DVD and Blu-ray collectors are being reminded that physical discs are not immune to decay, thanks to a phenomenon known as "disc rot". This occurs when environmental factors degrade the reflective layer inside a disc, corrupting the data it holds and, in some cases, rendering it unreadable. While the problem is relatively uncommon, awareness of its causes and warning signs is growing more important as people increasingly rely on physical media collections as a hedge against the unpredictability of streaming services.

Disc rot is typically caused by oxidisation, where oxygen reacts with the aluminium layer, alongside poor storage conditions such as extreme temperatures, humidity and direct sunlight, all of which can warp or loosen the disc's protective layers. Visible warning signs include bronze discolouration, pinpricks, holes or clouded patches, though the damage is sometimes only noticeable through playback problems. Cheaply made discs and faulty cases are particularly vulnerable, and laserdiscs suffer their own distinct form of decay caused by their adhesives. Sony estimates a properly stored DVD should last 30 to 100 years, though some Warner Bros. DVDs reportedly began rotting in under 20 years, underlining how much lifespan depends on disc quality and storage conditions.