DIN 66399 Material Classification E refers to information on electronic data carriers, for example chip cards and memory sticks. The Security Levels run from E-1 to E-7 with E-1 being recommended for data carriers with general data, which have to made illegible to E-7 for data carriers with top secret data where the strictest security standards shall be maintained.

E1

• Recommended, for example, for data carriers holding general data to be rendered illegible
• Particle size: Mechanically/electronically inoperable
• Shredded data can be reproduced without special knowledge or equipment, although the process is time-consuming

E2

• Recommended, for example, for data carriers holding general data to be rendered illegible
• Particle size: Split
• Shredded data can be reproduced with equipment, although the process is time-consuming

E3

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

E4

• 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

E5

• 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

E6

• Recommended, for example, for data carriers holding confidential information demanding an exceptionally high level of security
• Max. material particle size 1 mm²
• Shredded data cannot be reproduced even with special equipment

E7

• 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 0.5 mm²
• Shredded data cannot be reproduced in any way with the current state of science and art