DIN 66399 Material Classification O refers to information on optical data carriers, for example CDs, DVDs, and Blu-ray Disks (BDs). The Security Levels run from O-1 to O-7 with O-1 being recommended for data carriers with general data which have to made illegible, to O-7 for data carriers with top secret data where the strictest security standards must be maintained.

O1

• Recommended, for example, for data carriers holding general data to be rendered illegible
• Max. material particle size 2000 mm²
• Shredded data can be reproduced without special knowledge or equipment, although the process is time-consuming

O2

• Recommended, for example, for data carriers holding general data to be rendered illegible
• Max. material particle size 800 mm²
• Shredded data can be reproduced with equipment, although the process is time-consuming

O3

• Recommended, for example, for data carriers holding sensitive, confidential and personal data
• Max. material particle size 160 mm²
• Shredded data can only be reproduced with maximum effort and special equipment

O4

• Recommended, for example, for data carriers holding particularly sensitive, confidential and personal data
• Max. material particle size 30 mm²
• Shredded data can only be reproduced utilizing equipment that is not readily available commercially

O5

• Recommended, for example, for data carriers holding confidential information
• Max. material particle size 10 mm²
• Shredded data is unlikely to be reproduced even with special equipment

O6

• Recommended, for example, for data carriers holding confidential information demanding an exceptionally high level of security
• Max. material particle size 5 mm²
• Shredded data cannot be reproduced even with special equipment

O7

• Recommended, for example, for data carriers holding strictly confidential information demanding the highest security precautions (e.g. classified and top secret)
• Max. material particle size 0.2 mm²
• Shredded data cannot be reproduced in any way with the current state of science and art