Unfortunately CD’s and DVD’s are not built to last. Degradation in optical media refers to this decline in the physical quality of CDs, DVDs and Blu-rays over time. There are two main factors that this eventuality can be attributed to; material and environment.
Material factors:
-Disc Format. A CD-ROM has a different composition than a CD-RW, therefore they deteriorate at different rates.
-The manufacturer. There are variations in the dyes, plastics and alloys used, which in turn cause divergences in quality between brands.
-The equipment used to read or write the disc itself.
Environmental factor:
-Exposure to high temperature. Increase in heat speeds the degradation process by breaking down the recording layers of discs that utilise organic dye compounds.
– Extreme humidity. Moisture can seep into the cracks and scratches of a disc which could foster the growth of bacteria and/or mould; this can affect how effective the laser’s ability is to read the disc.
– Regular contact with UV. Direct sunlight accelerates the rate of aging of a disc. It renders the disc ineffective by altering the appearance of the recording layers.
–Dust, dirt and air pollution. Any foreign particles that accumulate on the disc surface and in cracks or scratches can damage the disc and cloud reading and recording.
Inappropriate handling or storage also contributes to an increased deterioration process of CDs, DVDs and Blu-rays.
As discs have a limited shelf life, no matter how well they are treated by the user, degradation can only be controlled to a certain extent. The core recording layers of a disc will naturally break down before the outer plastic takes away layers. The outer deterioration of the polycarbonate incurs damage mainly from rough handling, and is therefore not considered when measuring the disc’s overall shelf life.
Consequently, the lifespan of CDs, DVDs and Blu-rays contain a range of testing measurements and can be conservatively estimated, with some compact discs tending to outlast DVD formats:
- Unrecorded CD-R and CD-RW: 5-10 years
- Recorded CD-R: 50-200 years
- Recorded CD-RW: 20-100 years
- Recorded DVD-R: 30-100 years
- Recorded DVD-RW: up to 30 years
- Recorded BD-R and BD-RE: 30-200 years
Since Blu-ray is a newer technology, it should be noted that further testing and calculations are required to more accurately narrow a lifespan.
