近日，FDA对Valneva Scotland Limited的检查483缺陷报告中提及气流流型（气流可视化或烟雾试验）所用烟雾不当的缺陷：该公司未针对该烟雾用于洁净室层流罩的情况，评估烟雾的无菌性、颗粒产生及残留物可清洁性等因素，如下：
Dynamic smoke studies were performed utilizing smoke from a combustible source, smoke matches. This smoke has not been evaluated by your firm for use in cleanroom hoods for factors such as sterility of smoke, particle generation, and cleanability of residues. In addition, smoke cannot be visualized in all smoke study videos due to blocked camera angles by personnel and manual application of smoke by personnel.
动态烟雾试验（气流流型）使用了可燃来源（烟雾棒）产生的烟雾。贵公司未针对该烟雾用于洁净室层流罩的情况，评估烟雾无菌性、颗粒产生及残留物可清洁性等因素。此外，由于人员遮挡摄像头角度以及人工施烟，部分烟雾试验（气流流型）视频中无法清晰观测到烟雾。
气流流型测试的烟雾要求
Airflow Pattern Testing: There is an increasing expectation that airflow patterns in ISO 5/Grade A through ISO7/Grade B areas be video recorded. Considerations include the selection ofcamera angles, visibility of the smoke against the room background, the useoffiner (thinner) smoke streams to better show stream lines. Video narrative should describe what the viewer sees, with additional pertinent data (perhaps titles) showing date, personnel, air velocity at the filters, etc. Certainaerosols (smoke sources) may be unfit for airflow pattern testing, being eithertoo dense (such as smoke from dry ice and alcohol) or reactive with cleaningagents (titanium smoke sticks leave a catalyst residue that interferes withcertain sterilants). Some of the better smoke sources may require cleaning ofthe room surfaces before the room can be returned to service.
气流流型测试：对于 ISO 5/ A 级至 ISO 7/ B 级区域的气流流型，越来越要求对其进行视频记录。需要考虑的因素包括摄像机角度的选择、烟雾与房间背景的对比度、使用更轻（更薄）的烟雾以更好地显示气流流型。应有视频旁白描述所看到的内容，并附上相关数据（可能在标题），如日期、人员、过滤器处的空气流速等。某些气溶胶（烟雾来源）可能不适合用于气流流型测试，要么过于浓密（例如干冰和酒精产生的烟雾），要么会与清洁剂发生反应（钛烟棒会留下催化剂残留物，干扰某些消毒剂）。一些较好的烟雾源可能还需要在房间重新投入使用前对房间表面进行清洁。
PDA近期的培训中也提及气流流型测试（气流可视化测试或烟雾测试）中的常见误区：
Airflow Visualization Studies: A Misunderstood & Underutilized Tool气流可视化研究：一门被误解且未充分利用的工具
Smoke Studies are Often Approached as a Rubber Stamp Test. Often Conducted Under the Assumption That They Will Pass Because Other Cleanroom/Barrier System Tests Have Passed:
烟雾试验常被视为 “走过场” 测试，其开展往往基于 “其他洁净室 / 屏障系统测试已通过，此测试也会通过” 的假设，例如：
Air Volume and Air Velocity
风量和风速
Differential Pressure
压差
Filter Integrity
过滤器完整性
Particle Count
粒子计数
Heavier Than Air Fogging Systems for Air Flow Visualization (Smoke Studies) do not faithfully (accurately) follow the Actual Air Flow Patterns:
用于气流可视化（烟雾试验）的雾化系统如重于空气则无法如实跟随实际气流流型，存在以下局限：
Do not Identify Dead Spaces
无法识别死空间
Do not identify Eddy Currents
无法识别涡流
Resulting in the acceptance of unsuitable air patterns and aseptic operations being carried out in turbulent or deviant air flow conditions.
导致不合格的气流模式被接受，无菌操作在湍流或异常气流条件下进行。
Water, CO₂, Nitrogen Foggers are Unsuitable.
水、二氧化碳、氮气烟雾均不适合用于气流流型测试。
