Smoke Study

USP general chapter - 797

1. Unidirectional airflow
2. Sweeping action over and away from the product under dynamic conditions.
3. It is useful in identifying eddy currents and recirculation of air flow as a means of assessing risk of contamination in critical areas within a clean room.

First air should contact critical components or products before contacting anything else. It should be free of eddy currents or deviant air that can act as a channel or reservoir for contaminants.

It is important to evaluate air flow patterns to assure that these patterns do not pose a risk of distributing particles from sources such as surrounding environment, personal, operations, materials or equipment.

These tests are used to demonstrate that airflow under operational conditions doesn't contribute to contamination risk.

Regulatory bodies requires documented air pattern analysis with written conclusions including the effects of the aseptic interventions in critical areas.

Smoke study tells about the airflow characteristics of the ISO Class-5 environment.

Smoke study demonstrates the movement of particle in clean room.

Particle will be driven from HEPA, over the product on equipment.

Acceptance criteria of smoke study -

1. Airflow should continuously wash in a sequential manner - product, equipment, personal, cleanroom floor, walls, return raisers.
2. Laminarity of airflow patterns and no/ minimum turbulence in airflow and should be unidirectional in nature.
3. Dead spots if identified are justified with a scientific rational.

When smoke study requires to perform -
1. During initial area qualifications
2. New installation of equipment
3. Subsequent changes in equipment configuration
4. Any other change in existing system.

In order to assure its state of Qualification a routine periodic verification once in every one or two years depending on risk assessment and rationale derived.

The visual medium (smoke) must be neutrality buoyant, which means smoke should be lighter than air or shall have similar density to that of air.

Benefits of conducting smoke study -
1. Identify barrier technology or critical environment design issues.
2. Prevent environmental monitoring excursion, media fill and product failure by identifying eddy currents and deviant air flow patterns which can be corrected and properly monitored to address risk.
3. Prevent data integrity issues by identifying and correcting poorly designed, constructed, maintained, and integrated clean rooms and barrier system.
4. Evaluate Aseptic manipulation and techniques in relationship to air flow pattern.
5. Determine if gowning strategies and practices are adequate to support operations in conjunction with facility and barrier system design and integration.