Dust- and Germ-Free Room Classification and Variety

Dust- and Germ-Free Room Classification and Variety

Example of several basic things to be mindful of:

  1. There can be no dust or particles in the Clean Room
  2. Dust and particles in the Clean Room must be collected and eliminated
  3. Eliminate all causes of small particles as much as possible
  4. Reduce the number of blind spots where particles may accumulate inside the clean room as much as possible

The standard of Clean Rooms is defined by cleanliness. In general, industrial Clean Room (ICR) is classified using the US Federal Standard No.209b, where germ-free rooms use the guidelines set out by NASA.

Table 1: US Federal Standard No.209b
Clean Room Classes Particles Pressure Temperature Humidity Flow Illumination
Measured Particle Size (µm) Maximum permitted number of particles (/ft3) (mmAq) (℃) (%) Ventilation Frequency (LX)
100 Over 0.5 100 Over 13 Range: 19.4-25 Max: 45 Laminar Flow:
0.45m/s ±0.1m/s

1,080

1,620

1,000 Over 0.5
Over 5
1,000
10
Specified Value: 22.2 Min: 30
10,000 Over 0.5
Over 5
10,000
65
Error: ±2.8 Error: ±10 Turbulent Flow:
≥20 times/hr
100,000 Over 0.5
Over 5
100,000
700
Special Requirement: ±0.25 Special Requirement: ±5

 

Table 2: NASA Standard NHB5340.2 (NHB5340.2)
Clean Room Classes Particles (CR) Microbe Particles (BCR) Pressure Temperature Humidity Flow Illumination
Measured Particle Size (µm) Maximum permitted number of particles (/ft3) Max. No. of microbe particles (/ft3) Average microbe fall per week (/ft3) (mmAq) (℃) (%) Ventilation Frequency (LX)
100 Over 0.5 100 0.1 1,200 1.3以上 Specified Value 45 ∣ 50

Laminar Flow:
0.45m/s ±0.1m/s

Turbulent Flow:
≥20 times/hr

1,080

1,620

10,000 Over 0.5
Over 5
10,000
65
0.5 6,000
100,000 Over 0.5
Over 5
100,000
700
2.5 30,000