Paper shredders fall into five levels of security level 1 (lowest) to level 5 (highest) as defined in DIN32757.  For normal home use then a lower level of security is acceptable. In an office environment where information such as personnel and wage documents are being disposed, then a higher level (cross cut shredder model) would be suitable.

View are full range of paper shredders

Level 1
Description:  Low Level - General paperwork
Usage:  For shredding general internal documents.
Cutting Strip Cut (10.5mm), Cross Cut (10.5mm x 40-80mm)
Shredding Output Examples:
Strip Cut	Cross Cut

Level 2
Description:  Everyday - Everyday documents
Usage:  For internal documents such as notes, invoices, printouts, photo-copies
Cutting Style: Strip Cut (3.9mm)
Shredding Output Examples:
Strip Cut

Level 3
Description:  Confidential - Confidential documents
Usage:  For confidential documents, such as company internal documents, personal data
Cutting Style: Bulk reduction, Cross Cut (3.9mm x 30mm)
Shredding Output Examples:
Strip Cut	Cross Cut

Level 4
Description:  Sensitive - Sensitive documents
Usage:  For secret documents, such as documents and files relevant to the safeguarding of personal livelihood or a company's existence.
Cutting Style: Cross cut (1.9mm x 15mm)
Shredding Output Examples:
Cross Cut

Level 5
Description:  Top Secret - Secret documents
Usage:  Espionage-safe, for extremely high demands of security such as military or government departments.
Cutting Style: Cross cut (0.78mm x 11mm)
Shredding Output Examples:
Cross Cut