Current Portable Optical Media

  Endangered large 

Materials saved to DVDs, CDs or other optical media in the last five years where the reader devices are still supported and can be integrated easily into hardware infrastructure.

Digital Species: Portable Media

Trend in 2022:

No change No Change

Consensus Decision

Added to List: 2019

Trend in 2023:

No change No Change

Previously: Endangered

Imminence of Action

Action is recommended within three years, detailed assessment within one year.

Significance of Loss

The loss of tools, data or services within this group would impact on people and sectors around the world.

Effort to Preserve | Inevitability

It would require a small effort to preserve materials in this group, requiring the application of proven tools and techniques.


CDs, DVDs produced in the last five years.

‘Critically Endangered’ in the Presence of Aggravating Conditions

Poor storage conditions; encryption; digital rights management; lack of replication; lack of documentation; lack of periodic testing; lack of refreshment pathway; lack of access to readers; out of manufacturers’ warranty or no warranty; storage in paper files; copyright; environmental disasters; technical preservation measures.

‘Vulnerable’ in the Presence of Good Practice

Regular review and testing; replication; refreshment plan; comprehensive documentation; high quality storage; regular maintenance of readers; multiple readers available.

2023 Review

The 2019 Jury introduced this entry to ensure that the range of media storage is properly assessed and presented. The 2021 Jury agreed with the entry’s assigned risk classification with no noted changes towards increased or reduced risk.

The 2023 Council agreed with the risk classification of Endangered with the overall risks remaining on the same basis as before (no change to the trend). Additionally, the Council recommended that a nomination received for ‘DVDs produced under copyright’ would provide a valuable example to this entry rather than as a new, standalone entry (see below).

Additional Comments

This entry is highly dependent on who is looking after the portable media but made more difficult over time. The lack of granularity in the definition means that only general advice can be offered, such as to refresh media. In time, it may yet be more useful to split all storage media (maybe 100 items long) with an indication of how long these can be expected to last. In many cases, specialists can recover obsolete media, but the cost of employing them can become an aggravating condition.

Case Studies or Examples:

  • One example, presented to the Council through a 2023 nomination, concerns the loss of digital materials stored in DVDs. A 3,500 DVD ‘film collection’ was destroyed during the fire at the University Library Archives and Special Collections, University of Cape Town, South Africa. There were no backup copies in large part because of the (mis)understanding that they were prevented by copyright from making backup copies. This example extends beyond the loss of material in the optical media, particularly in respect to backups and issues surrounding copyright, but in the context of the entry shows how aggravating factors can place content at greater risk due to aggravating factors not only to copyright but also global warming with more such fires, floods and natural disasters to be expected. See News in Conservation (2021) ‘Devastating Cape Town fire destroys University Library Archives and Special Collections’, News in Conservation, International Institute for Conservation of Historic and Artistic Works, Volume 84, p. 8-9, June-July 2021. Available at: [accessed 24 October 2023]

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