Clean room specifications and cleanliness

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

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