NIST 800-88, explained in plain English
It's the standard almost every data-destruction company cites. Here's what it actually says, what it means for your drives, and what to ask any vendor who claims to follow it.
What is NIST 800-88?
NIST Special Publication 800-88, Guidelines for Media Sanitization, is published by the U.S. National Institute of Standards and Technology. It's the reference most organizations, auditors, and regulators point to when they ask how data should be removed from storage before a device is reused, recycled, or thrown away.
Its core idea is simple: the method should match the media and how sensitive the data is, and the result should be verified and documented. It doesn't prescribe one magic tool — it gives you three levels to choose from.
The three levels: Clear, Purge, Destroy
| Level | What it means | Typical use |
|---|---|---|
| Clear | Overwrite all user-addressable storage so the data can't be recovered with normal tools. | Working hard drives being reused or resold. |
| Purge | Techniques that defeat even laboratory recovery — for flash media, usually the drive's built-in sanitize or cryptographic-erase commands. | SSDs, NVMe drives, and higher-sensitivity data. |
| Destroy | Physically shred, crush, disintegrate, or pulverize the media so it can't be used again. | Failed drives, anything that can't be verified, or policy-mandated destruction. |
What about DoD 5220.22-M and “3-pass” wipes?
You'll still see the DoD 5220.22-M multi-pass overwrite advertised everywhere. It comes from an older Department of Defense manual and predates modern drives. For today's hard drives, NIST 800-88 treats a single overwrite pass followed by verification as sufficient — extra passes take longer without making the data any more gone.
If a contract or internal policy specifically names DoD 5220.22-M, it's fine to run it. Just don't assume more passes means more secure.
The step that actually matters is verification. A wipe you haven't read back is a wipe you're taking on faith.
Why SSDs are different
Solid-state drives spread writes across spare flash cells the operating system can't see, so a standard overwrite can miss data. That's why NIST 800-88 steers flash media toward Purge methods — the drive's own sanitize or secure-erase commands — or physical destruction. More on SSDs here.
What to ask a vendor who says “NIST 800-88 compliant”
- Which level do you use for which media? “We wipe everything the same way” is a red flag for SSDs.
- Do you verify every drive? Sampling isn't the same as verifying.
- What happens to drives that fail? The only right answer is physical destruction.
- Is the certificate per drive, with serial numbers? A batch receipt can't prove what happened to a specific device.
- Who has custody in between? Ask whether the work is subcontracted.
For the record, here's how we answer all five: our Trust Center lays it out.