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Materialklasse O (optische Datenträger)
In brief
Material class O of the DIN 66399 standard covers optical data carriers such as CDs, DVDs and Blu-ray Discs. For them, the standard defines seven security levels from O-1 to O-7, each with a maximum particle size after destruction. Because data on pressed or write-once discs cannot be erased, shredding into small particles is the usual way to make a CD or DVD securely unreadable.
Security levels of material class O
| Level | Maximum particle area |
|---|---|
| O-1 | 2.000 mm² |
| O-2 | 800 mm² |
| O-3 | 160 mm² |
| O-4 | 30 mm² |
| O-5 | 10 mm² |
| O-6 | 5 mm² |
| O-7 | 0,2 mm² |
Which level is necessary results from the protection class of the data. The classification into the system of material classes under DIN 66399 is explained in the guide DIN 66399: protection classes and security levels.
Optical data carriers in practice
The data layer of a CD or DVD lies in a thin layer of the plastic disc. A scratch or a break into a few pieces does not make the data securely unreadable. For small particles at high levels, special shredders or a Disintegrator is used. Discs in drives of decommissioned computers, in archive boxes or project folders are often overlooked.
At goods receipt, Second IT checks all delivered devices for storage media, including DVDs in drives, and registers them. For optical data carriers, clarify in the quote which security level you need.
Frequently asked questions about material class O
Can a writable DVD be erased?
Rewritable discs can be overwritten, but for secure proof destruction is usual. Write-once and pressed discs cannot be erased.
Is it enough to break a CD?
No. Large fragments still contain readable data areas. Only small particles at the appropriate level make the data unreadable.
Which level do I need for personal data?
That depends on the protection requirement. For data with a high protection requirement, at least O-3 is often recommended. Check your case with your data protection officer.
How large may the particles be after CDs and DVDs are destroyed?
That depends on the security level. At O-1, at most 2,000 mm² are allowed, at O-3 160 mm², at O-5 10 mm² and at O-7 only 0.2 mm². The higher the level, the smaller the pieces.
Where do companies overlook CDs and DVDs during decommissioning?
Often in drives of decommissioned computers, in archive boxes and in project folders. Check devices and filing areas specifically for optical data carriers before handover, so that no disc with data leaves the building unnoticed.
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