What principles should be considered when determining the sampling points for online laser particle monitoring?
To meet the GMP standards, cleanrooms for pharmaceutical production must reach the corresponding grade requirements. Therefore, these environments used for sterile production need to be strictly monitored to ensure the stability and controllability of the production process. Typically, a complete dust particle monitoring system is installed in the areas that require focused monitoring. This system includes components such as a control interface, control equipment, particle counters, air pipes, vacuum systems, and related software. In each critical area, a continuous measurement particle counter is equipped. Through instructions sent by the workstation computer, continuous monitoring and sampling are carried out in each area. The monitored data is transmitted to the workstation computer, which can display the data and generate reports for the operator to refer to after receiving it. The selection of the location and quantity of online dynamic monitoring of dust particles should be based on risk assessment research and ensure coverage of all critical areas.
The determination of sampling points for online laser particle counters refers to the following six principles:
1. ISO 14644-1 Standard: It stipulates that in unidirectional flow cleanrooms, the sampling port should face the direction of the airflow; in non-unidirectional flow cleanrooms, the sampling port should be oriented upwards. In both cases, the sampling speed at the sampling port should be as close as possible to the indoor airflow speed.
2. GMP Principle: The sampling head should be installed close to the working height and near product exposure areas.
3. The sampling location should not interfere with the normal operation of production equipment, nor should it affect the normal operation of personnel during the production process, and it should avoid impacting logistics channels.
4. The sampling location should not interfere with the normal operation of production equipment, nor should it affect the normal operation of personnel during the production process, and it should avoid impacting logistics channels.
5. The sampling location should be feasible for installation.
6. The sampling location should be above the horizontal plane of the critical point, and the distance from the critical point should not exceed 30 cm. For special locations where there is splashing or overflowing of liquid, which may cause the measurement data to exceed the standard of the grade area during simulated production conditions, the vertical distance limit can be appropriately relaxed, but it should not exceed 50 cm.
7. It is advisable to avoid placing the sampling location directly above containers to prevent air deficiency and turbulence above the containers.
After determining all the candidate sampling points, simulate the actual production environment and use a portable particle counter with a sampling flow rate of 100L/min to conduct a 10-minute sampling operation at each candidate point in the respective critical areas, and meticulously record the dust particle sampling data for all the points. Subsequently, compare and analyze the sampling results from multiple candidate points within the same area to identify the monitoring points with higher risks, and determine these points as the final installation locations for the dust particle monitoring point sampling heads.