Cleanliness level and division of dust-free workshops in food production, wear dust-free gloves, food hygiene quality is directly related to people's physical fitness and life safety. Factors affecting food hygiene quality include production raw materials and auxiliary materials, production process technology and production environment. The food production environment includes equipment (tools), personnel and air that may come into contact with food. The purpose of its safe production control is to prevent food from being processed under unsanitary conditions. Pollution control in clean rooms (areas) for food production is a key link in food production environment control, and its control objects include dust particles and microorganisms.
Compared with the original specification GBJ73-84, the air cleanliness level has increased from 4 levels to 9 levels, and the controlled particle size has increased from 2 (0.5µm and 5µm) to 6 (0.1µm, 0.2µm, 0.3µm, 0.5µm, 1µm, and 5µm), and the air cleanliness level is allowed to use the intermediate level between integers, such as 1.0, 1.1, 1.2...8.9, 9.0.
Cleanliness level Maximum allowable number of dust particles/(PC/M3) Maximum allowable number of microorganisms Ventilation frequency
≥0.5µm ≥5µm floating bacteria/(pieces/M3) settling bacteria/(pieces/dish)
100 level 3500 0 5 1 vertical laminar flow 0.3m/s
horizontal laminar flow 0.4m/s
10000 level 350000 2000 100 3 ≥20 times/h
100000 level 3500000 20000 500 10 ≥15 times/h
300000 level 10500000 60000 15 ≥10 times/h
Note: PC/M3 is the number of suspended particles per unit volume of air.
Air cleanliness refers to the amount of suspended particles in the air in a clean environment. Generally, the higher the dust concentration in the air, the lower the air cleanliness, and the lower the dust concentration, the higher the air cleanliness. The air cleanliness level in clean rooms and related controlled environments is divided according to the concentration of suspended particles in the air, that is, the air cleanliness level is determined by the maximum allowable number of particles per cubic meter of air.
