DIN 66399 explained: when do you choose P-5 and when P-6?
At every quote for document destruction you encounter the same term: DIN 66399. Usually followed by a letter and a number, such as P-4, P-5 or P-6. For anyone who does not read the standard daily it sounds like technical jargon, but the choice has direct consequences for your GDPR compliance and for the price per kilo of destruction. This article explains what the P-levels mean, when to choose which one and why the step from P-5 to P-6 is sometimes necessary and sometimes overkill.
DIN 66399 is the successor to the old DIN 32757 and was published in 2012. The standard splits media into six categories: P (paper), F (film and microfiche), O (optical media such as CD and DVD), T (magnetic strip media), H (hard drives) and E (electronic media such as USB and SSD). For each category there are seven security levels, where the highest number always yields the finest destruction.
The three protection classes as a basis
Before choosing a P number, you must know which protection class your information falls into. DIN 66399 distinguishes three.
- Class 1: normal data. Public or lightly confidential. Think of advertising material addressed to customers.
- Class 2: confidential data. Unauthorised use harms the organisation or the data subject. Think of HR records, invoices, contracts.
- Class 3: strictly confidential and secret data. Unauthorised use endangers life, health, freedom or fundamental rights. Think of medical files, research results, whistleblower information.
The GDPR does not use these classes literally, but the thinking aligns well. Special categories of personal data from GDPR article 9 fall in practice within class 3.
P levels for paper: from letter post to special categories
The P range contains seven steps. In practice you see mainly P-4, P-5 and P-6 in the Netherlands. Higher P-7 only occurs in government, defence and top-secret dossiers.
- P-1: strips up to 12 mm wide. Only for public material. Wholly insufficient for personal data.
- P-2: strips up to 6 mm. Still strip-cut. Unsuitable for confidential work.
- P-3: particles of max 320 mm². Suitable for class 1, not for personal data.
- P-4: particles of max 160 mm² with a maximum strip width of 6 mm. The lower bound for regular GDPR-obliged documents.
- P-5: particles of max 30 mm² with a strip width up to 2 mm. For special categories and all class 3 paper.
- P-6: particles of max 10 mm² with a strip width up to 1 mm. For very highly confidential material.
- P-7: particles of max 5 mm². Top-secret level, military and intelligence.
A P-4 shred is still reconstructable with some patience. From P-5 onwards reconstruction becomes practically impossible. From P-6 the shred is effectively confetti.
Which level fits which document?
The most frequently asked question is: how do I translate my archive to a P number? Below is the practice for Dutch SMEs and business service providers.
P-4: the standard for regular personal data
Sufficient for: payroll records, debtor and creditor folders, standard contracts, marketing lists with address details, CVs after a job rejection, bank statements, annual accounts. In effect, everything that falls under the GDPR but does not touch a special category.
P-5: for special categories and financially sensitive material
For medical files, absence reports, diagnoses, data on sexual orientation, political conviction, religion, criminal data. Also used by banks, financial advisers and insurers for KYC files under the Wwft. Notaries and lawyers choose P-5 for files covered by professional confidentiality, see also our article on NOvA rules of conduct and file handling for lawyers.
P-6: for top-tier research, R&D and exceptional sensitivity
Rarely needed in SMEs. P-6 is encountered at pharma, biotech, defence suppliers, copyrighted manuscripts and top-secret M&A files. Also requested by lawyers who wish to demonstrate a specific professional secret in criminal proceedings.
Not sure which P-level you need?
We advise per document type which DIN 66399 level fits your situation. On-site shredder at the door, certificate per order, no fuel surcharge.
Request a quoteThe confusion around microfiches and blueprints
P levels apply to flat paper. For microfiches and 35mm film the F range applies, for large-format blueprints P formally still applies, but you need a shredder that can handle the format. Small office machines usually achieve P-4 on A4, but drop below P-4 as soon as they are constrained by thicker materials or ring-binder sheets with plastic. So ask for the certified cut size under load, not for the theoretical value.
What should appear on your certificate?
A destruction certificate without mention of the DIN 66399 level is incomplete. A correct certificate states:
- Security level (for example P-5 for paper, H-4 for hard drives, E-4 for SSDs).
- Weight or number of units.
- Method of destruction (on-site shredder, stationary industrial installation, disintegrator).
- Date and location.
- Unique order number.
- Signature of the operator.
More about the complete content can be found in our article on what should appear on a Certificate of Destruction.
Cost: does P-5 versus P-6 make much difference?
P-5 is in practice 10 to 25 percent more expensive than P-4, depending on volume. The step to P-6 can add another 20 to 40 percent, because industrial shredders need more passes to deliver the same kilos in finer particles. For a standard SME archive P-6 is rarely efficient. Choose P-5 for sensitive material, P-4 for the rest, and combine the two in a single session to spread transport costs.
In summary
DIN 66399 is not a law but an industry standard that in GDPR practice effectively serves as a benchmark. For the bulk of Dutch business P-4 is the minimum standard, P-5 the safe choice for sensitive categories, and P-6 an upgrade that you only acquire when the dossier is worth it. Always ask for a certificate with the standard on it and be critical if a provider speaks of ‘DIN-compliant’ without a P number. That phrase literally says nothing.
Unsure which level fits a specific category? Call us or request a quote via desnipperaar.nl. We advise for free on retention periods, volume and the correct DIN classification.