13.1 How many times can a BD-RE disc be rewritten?
13.2 How long will data on a BD disc remain readable?
13.3 What is the best way to handle and store a BD disc?
13.1 How many times can a BD-RE disc be rewritten?
There is a limit to the number of times the phase-change recording layer in a BD-RE (rewritable) disc can be reliably switched between its crystalline and amorphous states (cyclability). BD-RE test specifications require that discs, at minimum, be rewritable at least 1,000 times. However, different materials, layer designs and fabrication processes may allow a greater number of cycles. For example, some manufacturers promote discs capable of 10,000 or more rewrites. In addition, under certain circumstances, BD-RE can employ defect management to actively verify data and relocate problems to spare areas of the disc taken out of the Data Zone(s).
| Optical Disc Format | Advertised Number of Overwrite Cycles |
| BD-RE | ≥ 10,000 |
| BD-RE XL | 1,000 |
| ADA-RE | 1,000 |
| HD DVD-RW | 1,000 |
| DVD-RW | 1,000 |
| DVD+RW | 1,000 |
| DVD-RAM | 100,000 |
| CD-RW | 1,000 |
| Professional Disc | ≥ 10,000 |
| Ultra Density Optical (UDO) | ≥ 10,000 |
| Phase-Change Dual (PD) | 500,000 |
| Matsushita/Panasonic Rewritable Optical Disk | 100,000 |
13.2 How long will data on a BD disc remain readable?
Several manufacturers and marketers claim that information written to BD-R (recordable) and BD-RE (rewritable) discs will remain readable for 30 to 200 years. Life expectancy of all data storage media is, however, notoriously difficult to calculate reliably and accelerated age testing methods and assumptions employed to arrive at those estimates are sometimes controversial. BD technology, of course, is in its infancy and lifetime data collected and published is extremely limited.
13.3 What is the best way to handle and store a BD disc?
Always handle a BD by its outer edges, by the center hole or center-hub clamping area. Avoid flexing or dropping the disc or exposing it to direct sunlight, excessive cold, heat or humidity. Handle only when being used and do not eat, drink or smoke close by. Discs should be stored in jewel cases or video boxes rather than sleeves since cases will not contact the discs’ surfaces and provide better protection against dust, debris, scratches, light and rapid humidity changes. Once placed in their cases discs can be further protected by keeping them in a closed box, drawer or cabinet. For long-term storage situations it is prudent to follow manufacturer instructions and consult the various international standards for preserving optical media.
| Standard | Description |
| ISO 18925:2008 | Imaging Materials – Optical Disc Media – Storage Practices |
| ISO 18934:2006 | Imaging Materials – Multiple Media Archives – Storage Environment |
| ISO 18938:2008 | Imaging Materials – Optical Discs – Care and Handling for Extended Storage |
| Condition | BD-R | BD-RE | DVD-ROM | DVD-R SL | DVD+R SL | DVD-R DL | DVD+R DL | DVD-RAM | DVD-RW SL | DVD+RW SL | CD-ROM |
| Specification | BD-R Part 1 | BD-RE Part 1 |
ECMA-267 | ECMA-359 | ECMA-349 | ECMA-382 | ECMA-364 | ECMA-330 | ECMA- 338 |
ECMA- 371 |
ECMA-130 |
| Temperature (˚C) |
-10 to 55 | -10 to 55 | -20 to 50 | -20 to 50 | -10 to 55 | -20 to 50 | -10 to 55 | -10 to 50 | -20 to 50 | -10 to 55 | -20 to 50 |
| Relative humidity (%) |
5 to 90 | 5 to 90 | 5 to 90 | 5 to 90 | 3 to 90 | 5 to 90 | 3 to 90 | 3 to 85 | 5 to 90 | 3 to 90 | 5 to 90 |
| Absolute humidity (g/m3) |
1 to 30 | 1 to 30 | 1 to 30 | 1 to 30 | 1 to 30 | 1 to 30 | 1 to 30 | 1 to 30 | 1 to 30 | 1 to 30 | NA |
| Atmospheric pressure (kPa) | 60 to 106 | 60 to 106 | 75 to 106 | 75 to 106 | 60 to 106 | 75 to 106 | 60 to 106 | 75 to 106 | 75 to 105 | 60 to 106 | 75 to 105 |
| Temperature variation (˚C/h) | ≤15 | ≤15 | ≤15 | ≤15 | ≤15 | ≤15 | ≤15 | ≤10 | ≤15 | ≤15 | NA |
| Relative humidity variation (%/h) | ≤10 | ≤10 | ≤10 | ≤10 | ≤10 | ≤10 | ≤10 | ≤10 | ≤10 | ≤10 | NA |
| Wet bulb temperature (˚C) |
NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | ≤29 |
| Condition | BD-R | BD-RE | DVD-ROM | DVD-R SL | DVD+R SL | DVD-R DL | DVD+R DL | DVD-RAM | DVD-RW SL | DVD+RW SL | CD-ROM |
| Specification | BD-R Part 1 | BD-RE Part 1 | ECMA-267 | ECMA-359 | ECMA-349 | ECMA-382 | ECMA-364 | ECMA-330 | ECMA-338 | ECMA-371 | ECMA-130 |
| Temperature (˚C) |
5 to 55 | 5 to 55 | -25 to 70 | -25 to 70(read) -5 to 55 (write) |
5 to 55 | -25 to 70 (read) -5 to 55 (write) |
5 to 55 | 5 to 60 | -25 to 70 (read) -5 to 55 (write) |
5 to 55 | -25 to 70 |
| Relative humidity (%) |
3 to 90 | 3 to 90 | 3 to 95 | 3 to 95 (read) 3 to 95 (write) |
3 to 85 | 3 to 95 (read) 3 to 95 (write) |
3 to 85 | 3 to 85 | 3 to 95 (read) 3 to 95 (write) |
3 to 85 | 10 to 95 |
| Absolute humidity (g/m3) |
3 to 90 | 0.5 to 30 | 0.5 to 60 | 0.5 to 60 (read) 0.5 to 30 (write) |
1 to 30 | 0.5 to 60 (read) 0.5 to 30 (write) |
1 to 30 | 1 to 30 | 0.5 to 60 (read) 0.5 to 30 (write) |
1 to 30 | 0.5 to 60 |
| Atmospheric pressure (kPa) | 3 to 90 | 60 to 106 | NA | NA | 60 to 106 | NA | 60 to 106 | NA | NA | 60 to 106 | NA |
| Temperature gradient (˚C/h) | NA | NA | NA | ≤15 (read) | ≤10 | ≤15 (read) | ≤10 | ≤10 | ≤15 (read) | ≤10 | NA |
| Relative humidity gradient (%/h) | NA | NA | NA | ≤10 (read) | ≤10 | ≤10 (read) | ≤10 | ≤10 | ≤10 (read) | ≤10 | NA |
| Sudden change of temperature (˚C) | NA | NA | ≤50 | NA | NA | NA | NA | NA | NA | NA | ≤50 |
| Sudden change of relative humidity (%) | NA | NA | ≤30 | NA | NA | NA | NA | NA | NA | NA | ≤30 |
