Clean room specifications and cleanliness

Clean room specifications and cleanliness

 

Abstract of NASA standard of bio-clean room (NHB-5340-2)

Classification Dust particles Microbial particle
Particle size Cumulative number of particles Floating amount Sedimentation amount
μm Pieces/ft3 Pieces/㎥ Pieces/ft3 Pieces/㎥ Pieces/ft3 Week Pieces/㎥ Week
100 ≧0.5 100 3,500 0.1 3.5 1,200 12,900
10,000 ≧0.5
≧5.0
10,000
65
350,000
2,300
0.5 17.6 6,000 64,600
100,000 ≧0.5
≧5.0
100,000
700
2,500,000
25,000
2.5 88.4 30,000 323,000

 

Cleanliness by industry

Industry Contents Process Class (cleanliness)
100 1000 10000 100000
Parts and device factory Electronic devices Magnetic tape, small relay, printed board, precision instrument Manufacture
Assembly
Semiconductor Mask matching, Etching vapor deposition, Polishing, Purification, Diffusion Manufacture
packing
precision equipment Bearing, clock, printing, camera, lens, film Processing / Manufacturing
Assembly
Food factory Bakery, confectionery, noodle making Bread, Castella, Rice cakes, Bean paste, Japanese sweets, Boiled noodles, Instant noodles Cooling / packaging
Manufacture
Meat and fish meat processing Ham, sausage, fish sausage,boiled fish paste, frozen pack Cooling / packing
Processing
Cooking, side dishes Tofu, natto, simmered, boxed lunch Cooling / packing
Processing
Liquid, paste food Jam, cream, chocolate syrup, jelly Filling · packaging
Processing / Manufacturing
Brewed goods Miso, Soy Sauce, Liquor, Beer Filling · packaging
Preparation
Dairy products Milk, pudding, ice cream, cheese, butter Filling · packaging
Preparation
Laboratory Inspection and analysis
Others Agriculture and forestry Mushrooms, Plants, Aquaculture Culture of fungus
cultivation

 

Dust concentration in natural environment

Place / situation Dust concentration number/ft3 ≧
stratosphere ≦100
Rural area (fine weather after the rain / no wind) 100,000~300,000
residential area 1,000,000~
Office where employees are working 2,000,000~5,000,000
Factory area 5,000,000~10,000,000
Conference room to do smoking 10,000,000~

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