Airflow Visualization Analysis or “Smoke Studies” are performed to ensure that airflow within an ISO Class 5 environment (critical airflow area) is without turbulence, re-flux or obstruction. Smoke Studies can be extremely beneficial when training or re-certifying operators. Allowing operators to witness obstructed airflow and visualize where air is without turbulence is an excellent way to illustrate where first air is most abundant and where manipulations should occur. Likewise, performing Smoke Studies during mock manipulations allows operators to be more attentive to appropriate aseptic technique.
The main criteria to determine the worst case operation is based on Smoke Studies performed in Technical Study Protocols (TSPs) for all allowed critical operations. A second emphasis is given to the number of operators within the Environmental Contamination Control Cabinet (ECCC), quantity and size of materials, complexity of operations and potential impact to product quality. The System Owner and representatives from Validation, Engineering, Manufacturing, Quality Control (QC) and Quality Assurance (QA) should collaborate to determine which operations would be considered the worst case for each ISO 5 ECCC. Examples of an ECCC are Laminar Flow Hood, Bio-safety Cabinet, Isolator, and Robots used for Media Fill, Trypsinization, Harvest etc.
For ECCCs, this criterion is based on the overall results of each critical operation in the Smoke Study. Critical elements that can determine these overall results are as follows:
- Number of operators performing manipulations in the ECCC (multiple would be worst-case)
- Number and complexity of movements/manipulations (e.g., bottling would be a worst-case when compared to sampling because it requires more movement)
- Number and size of items used to perform the operation (move items means there is less room for safe movements/manipulations)
- Risk to forward process materials
Number of operators, number and complexity of manipulations and number and size of items can all directly impact the risk to forward process materials. Using proper aseptic technique and being mindful of these critical elements will empower operators to play a significant role in maintaining quality and compliance.
Written By: Theo Tselios, Consultant
ICQ Consultants, Corp.