Collection: Security Level 4 Shredding

DIN 66399 Security Level P-4 limits the maximum particle area to 160 mm², with a maximum particle width of 6 mm. These are cross-cut machines; common shred sizes are 4 x 40 mm or 5/32" x 1-1/2". P-4 is the most widely specified level in professional offices and the practical baseline for any organisation handling personal data.

P-4 is appropriate for confidential personal and commercial information: HR and personnel files, payroll, contracts, invoices, patient administration paperwork, customer records, bank correspondence and internal financial reporting. It is the level most commonly cited when organisations need a documented, proportionate destruction standard for regulated records.

To be clear about what P-4 is not: it is not a classified-material level, it is not “NSA-certified”, and it is not suitable for national security information. NSA/CSS 02-01 is a separate US requirement calling for a maximum 1 mm x 5 mm particle from a specifically evaluated model — roughly thirty times finer than P-4.

Typical buyers are corporate offices, medical and dental practices, law and accountancy firms, HR departments, banks and public sector teams. If you need higher assurance for strategy, legal or medical files, look at P-5. Our DIN 66399 guide explains where each boundary sits.