Chain of custody best practices for USP 797 labs

A proper chain of custody is not just a compliance checkbox — it is the foundation of defensible test results. If your chain-of-custody documentation has gaps, your results can be challenged.

What a complete CoC must capture

• Client and facility identification — no vague locations. Sample locations must correspond to a defined facility map.
• Sample collection details — date, time, person, method, conditions.
• Media and reagent lot info — manufacturer, lot, expiry per item.
• Air sampler equipment — serial number and calibration expiry per event.
• Laboratory receipt acknowledgment — who received, when, in what condition.

Where most labs have gaps

• Handwritten forms with illegible or incomplete fields.
• Informal media lot tracking — sticky notes and mental notes.
• Calibration certificates in a filing cabinet rather than linked to the record.
• No chain of custody for sample transport.

Best practices

1. 01Use digital CoC forms with required-field enforcement.
2. 02Link media lots to a database, not a text field.
3. 03Select air samplers from an equipment registry with calibration tied in.
4. 04Retain the submitted CoC as a locked record.
5. 05Generate a CoC PDF as a permanent chain-of-custody document.