Investigate an out-of-specification lab result

Practice the sequence you already learned for “Investigate an out-of-specification lab result” until the order feels automatic. Practice FDA OOS guidance. The lot is quarantined, Phase I is documented before any invalidate-or-retest decision, and the sample is not retested into compliance.

1. Quarantine the lot.
2. Notify QA when the OOS is obtained.
3. Complete the Phase I laboratory investigation: method, instrument, and analyst.
4. Invalidate the result only if an assignable laboratory error is proven.
5. If the OOS is confirmed, expand to a full-scale investigation.
6. Retest only under the written protocol, not to average away the OOS.
7. Disposition the lot with QA; do not ship on an open OOS.