Critically Endangered small

Materials saved to flash or other solid-state storage devices where the media is out of warranty and reader devices may no longer be supported or integrated easily into hardware infrastructure: typically, more than five years old.

Group: Portable Media

Trend in 2021:

Consensus Decision

Added to List: 2019

No change No Change

Previous classification: Critically Endangered


Trend in 2022:


No change No Change


Imminence of Action

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

Significance of Loss

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

Effort to Preserve

It would require a major effort to prevent losses in this group, including the development of new preservation tools or techniques


USB sticks and pen drives; Flash storage in cameras and phones; certain types of portable hard disk

‘Practically Extinct’ in the Presence of Aggravating Conditions

Poor physical storage; inability to access readers; no replication; encryption

‘Endangered’ in the Presence of Good Practice

Active management; dependable access to readers; strong documentation; documentation independent from the media

2021 Jury Review

This entry was added in 2019 to ensure that the range of media storage is properly assessed and presented. Solid state media – typically flash – provides very fast access to data but can fail without warning. This is because it is typically subject to a limited number of program/erase cycles, as well as ‘read/disturb’ effects. Storage at scale also means the percentage likelihood of failure increases. The 2021 Jury agreed with the entry’s assigned risk classification with no noted changes towards increased or reduced risk.

Additional Comments

Early generations of media and cheap giveaways are not robust and can deteriorate significantly over time.

Scroll to top