Smoke Study
Airflow Visualization Study
What a definition is not
A definition is SPEQ’s plain-language decode of how a term is used in practice, cited to the documents that define it. It is a practitioner reference, not legal or regulatory advice, it does not replace the definition in the source, and where a regulator’s wording differs the regulator’s wording governs.
A smoke study (airflow visualization) uses a visible, neutrally buoyant fog to make cleanroom and critical-zone airflow patterns visible on video, demonstrating that unidirectional air sweeps contamination away from exposed product and that no turbulence or dead zones draw contamination toward it. It is direct visual evidence that the protection is real under actual conditions.
Studies are performed under dynamic conditions — with equipment running and operators performing representative interventions — because it is operator movement and machine motion that disrupt first air. The video record is a key inspection artifact and often reveals turbulence that airflow measurements alone would not.
EU GMP Annex 1 (2022) made dynamic airflow visualization an explicit expectation for critical zones, and findings from smoke studies should feed back into intervention design, equipment layout, and aseptic technique — not merely be filed.
- —Visualizes unidirectional airflow protecting exposed product.
- —Performed dynamically, with interventions represented.
- —Explicit Annex 1 (2022) expectation for critical zones.
- —Findings should drive intervention and layout improvements.
EU GMP Annex 1 (2022) airflow visualization requirement; FDA guidance, Sterile Drug Products Produced by Aseptic Processing (2004).
Frequently asked questions
What does Smoke Study stand for?
Smoke Study stands for Airflow Visualization Study.
What is Smoke Study?
A smoke study (airflow visualization) uses a visible, neutrally buoyant fog to make cleanroom and critical-zone airflow patterns visible on video, demonstrating that unidirectional air sweeps contamination away from exposed product and that no turbulence or dead zones draw contamination toward it. It is direct visual evidence that the protection is real under actual conditions.
Which regulations cover Smoke Study?
EU GMP Annex 1 (2022) airflow visualization requirement; FDA guidance, Sterile Drug Products Produced by Aseptic Processing (2004).