Now that the discussion of the new version of GMP is getting deeper and deeper, we understand that the requirements and regulations of the new version are constantly improving. The negative pressure weighing hood as a weighing protection device has been widely used in the sampling room of the pharmaceutical company and in the weighing and batching workshop. Next, we will discuss some of the concerns of the performance of the negative pressure weighing hood. Discussion on performance verification test and acceptance criteria of negative pressure weighing cover under the new GMP 1, background introduction With the deepening of the new GMP and the increasing requirements of the regulations, the negative pressure weighing hood as a weighing protection device has been widely used in the sampling room of the pharmaceutical company and in the weighing and batching workshop. In the weighing process in the negative pressure weighing hood, the product is often exposed, so it should naturally belong to the direct impact system that directly affects the quality of the product. It must be verified and verified according to the principle of risk control. Next, we will discuss some of the concerns of the performance of the negative pressure weighing hood. 2, test content The test of the negative pressure weighing hood should generally focus on high-efficiency on-site leak detection, airflow pattern, wind speed and uniformity, ratio of exhaust air volume, illuminance, temperature, noise, cleanliness and other parameters. 2.1, efficient leak detection If the leak detection is not carried out after efficient installation, the installation effect and the high efficiency damage during transportation cannot be guaranteed. Therefore, after installation, the on-site leak detection is generally performed efficiently after installation. The test uses a calibrated photometer and aerosol generator. Devices such as symmetrical hoods typically use a cold-smoke aerosol generator. After the aerosol concentration generated upstream is stable between 20-30 ug/L, the concentration is recorded, and then the downstream of the scanning filter is started. The scanning speed is 3-5 cm/s, and the filter surface is 2-4 cm, and the scanning route is suitable. All filter faces and bezel areas should be covered to ensure that each area is swept. Judging criteria: High-efficiency downstream does not detect a leak rate of more than 0.01%. 2.2, airflow pattern Airflow flow test should take into account the product exposure position, operator station, flow from clean to dirty flow. Ensure that the product is exposed to uncontaminated "first-hand clean air" to ensure that no airflow vortexes, circulates or spreads into the operator's breathing zone, causing injury to the operator. The test uses a water mist generator dedicated to the airflow type test, and records the airflow pattern with the camera equipment. Judging criteria: The airflow is in a unidirectional flow state with no eddy currents, backflow or diffusion. 2.3, wind speed and uniformity The protection function of the negative pressure weighing cover is formed by a good air flow with a certain wind speed. Only a uniform feeding and returning wind can form a good air flow, and only a certain wind speed can achieve the effect of suppressing the diffusion of dust. A, air supply A point test was taken at each of the equalizing membrane panels using a calibrated anemometer at 5-15 cm directly below the exit surface. Take 5 points for each membrane surface and calculate the average and air volume. Judging criteria: air supply wind speed is 0.36-0.54m/s, and the average speed of each film surface is also within 10% of the total average speed. In addition, none of the points deviated from the mean value of the film surface to which it belongs. B, returning to the wind The return air velocity was measured 3-5 cm from the retracted style grid using a calibrated anemometer. Take 5 points for each back style grid and calculate the average. Judgment criteria: The average speed of each part is within 10% of the total average error, and either data does not exceed 12% of the mean wind speed of the grid. 2.4, the proportion of exhaust air volume The reason why the negative pressure weighing hood forms a negative pressure is that the air volume that is efficiently discharged at the top causes the air supply volume of the air supply surface to be smaller than the return air volume of the return air surface, so that the equipment must absorb a part of the wind from the operating room in which it is located. Make up for the difference between the two to form a negative pressure zone. The proportional control of the exhaust air volume directly determines the effect of the negative pressure protection. The air volume is used to measure the discharge air volume, the data is recorded, and the ratio between the two is calculated based on the air flow rate measured by the wind speed and the uniformity test. Judging criteria: The discharge air volume should be between 5% and 15% of the total air supply. 2.5, temperature Because the fan in the weighing hood generates heat during operation, if there is no cooling measures, long-term operation will cause the indoor temperature to rise to an inappropriate value. Generally, for the weighing cover that needs to be operated for a long time, the cooling coil can be cooled. For the weighing cover with short running time, the method of specifying the longest continuous use time can be adopted to ensure that the temperature does not exceed the standard, and the The room is cooled by means of separate cooling. There should be a venting wind, and the weighing hood is an open device, and if a temperature rise occurs, it affects the entire temperature rise of the operating room in which it is located. According to the area distribution sampling point, no less than 0.5 meters from the wall, evenly distributed 5 points (should ensure at least one point inside the weighing cover), measured at the working surface height. Use a calibrated thermometer to record the room temperature before the weighing cover is turned on and calculate the average. Then turn on the device to operate, measure the room temperature again before the end of the work, that is, the longest running time, and calculate the average value. Judging criteria: The operation of the negative pressure weighing hood does not cause the indoor temperature to rise above 2 °C. 2.6, noise / illumination Because of the operator's operation in the operating room, certain noise and illumination levels are beneficial to the comfort of the staff, thus reducing the chance of error. From the perspective of EHS, noise is also an indicator that should be controlled. Judging criteria: noise: 75 decibels or both parties; illumination: 500lx or both parties. 2.7, cleanliness The negative pressure weighing hood is somewhat similar to the Class A air supply in C+A in GMP, and its cleanliness must meet Class A requirements under static conditions. The required sampling points are calculated based on the wind exit area during the measurement. The sampling points were evenly placed at a distance of 0.8 m from the ground for testing. Judging criteria: A level A static requirement is met. 3, matters needing attention and suggestions In addition to the above properties, microbial control is also crucial, but because microbial control is more dependent on the entire hardware and software management level of enterprise air conditioners and clean rooms, rather than relying solely on the negative pressure weighing cover itself, this is usually Air conditioning and clean room performance are confirmed at the time of confirmation and are not carried out here. medical protective suit with shoecover,medical protective suit without shoes cover,hazmat suit,hooded coverall without seal tape Shandong Zhushi Pharmaceutical Group Co.,LTD , https://www.sdzs-medical.com
