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An out-of-specification laboratory result should be treated as a quality question requiring investigation, not simply as a reason to repeat the test.

First Confirm the Basics

Review:

  • product;
  • batch;
  • sample identity;
  • parameter;
  • method;
  • units;
  • specification;
  • acceptance criterion.

Review Sampling

Ask whether the submitted sample adequately represented the lot.

Review Raw Materials

Could an ingredient explain the result?

Review Manufacturing

Consider:

  • formulation;
  • weighing;
  • blending;
  • sanitation;
  • processing;
  • storage.

Review Other Analytical Results

A microbiology failure may require a different investigation from a heavy-metal or composition failure.

Should You Retest?

Possibly—but only if additional testing addresses a defined investigative question.

PBR's decision framework explicitly cautions against using laboratory testing without considering the specification, detection limit, sample and decision rule.

Speak with PBR about the failed result and the decision your follow-up testing needs to support.

Choose PBR — Because Precision Matters, Defining Excellence in Laboratory Services Since 1984.