Cleanroom air cleanliness standard

1、 There is no unified standard for air cleanliness in cleanrooms internationally, and each country has its own level standards. The provisions of China’s “Good Manufacturing Practice for Drugs” are as follows:
Cleanliness level Dust particle count/m3 Active microbial count
0.5 μ m 5 μ m planktonic bacteria/m3 sedimenting bacteria/dish
Level 100 ≤ 3500 0 ≤ 5 ≤ 1
10000 level ≤ 350000 ≤ 2000 ≤ 100 ≤ 3
100000 level ≤ 3500000 ≤ 20000 ≤ 500 ≤ 10
300000 level ≤ 10500000 ≤ 60000, currently missing ≤ 15
The clean room should maintain positive pressure, that is, the static pressure value of the high-level clean room should be higher than that of the low-level clean room; Cleanrooms are connected in order of cleanliness and have corresponding pressure differences (pressure difference ≥ 10mmH2O) to prevent air from low-level cleanrooms from flowing back to high-level cleanrooms; Unless there are special requirements for temperature and humidity in the process, the temperature in the clean room should be 18-26 ℃ and the relative humidity should be 45-65%.

2、 The commonly used methods for measuring dust concentration in clean rooms include light scattering method, membrane microscopy method, photoelectric colorimetric method, etc.
The light scattering method utilizes the principle that the intensity of the scattering method is proportional to the surface area of the dust particles, and the number of pulse signals corresponds to the number of dust particles. The particle size and number are displayed on a digital tube.
The membrane microscopy method uses microporous membrane vacuum filtration to filter dusty air, capturing dust particles on the surface of the membrane. Then, acetone vapor fumigation is used to form a transparent body on the membrane. After counting with a microscope, the physical properties such as shape, size, and color of the dust particles can be directly observed.
The photoelectric colorimetric method utilizes the principle that the optical density is proportional to the dust accumulation, and uses a photoelectric colorimeter to measure the difference in transmittance of the filter paper before and after filtration, directly measuring the dust content in the air.
In addition to using an air purifier to purify the air, a better method of purifying the air is ventilation.