Standard of Particles in Cleanroom

Class list of National Federal Standard 209E

Cleanliness class
Maximum numbers of particles
0.1μm 0.2μm 0.3μm 0.5μm 5μm
Unit volume Unit volume Unit volume Unit volume Unit volume
Metric
system
fps
system
(m3) (ft3) (m3) (ft3) (m3) (ft3) (m3) (ft3) (m3) (ft3)
M1   350 9.91 75.7 2.14 30.9 0.875 10 0.283 ... ... ... ...
M1.5 1 1,240 35.0 265 7.5 106 3 35.3 1 ... ... ... ...
M2   3,500 99.1 757 21.4 309 8.75 100 2.83 ... ... ... ...
M2.5 10 12,400 350 2,650 75 1,060 30 353 10 ... ... ... ...
M3   35,000 991 7,570 214 3,090 87.5 1,000 28.3 ... ... ... ...
M3.5 100 ... ... ... ... 36,500 750 10,600 300 3,530 100 ... ... ... ...
M4   ... ... ... ... 75,700 2,140 30,900 875 10,000 283 ... ... ... ...
M4.5 1000 ... ... ... ... ... ... ... ... ... ... ... ... 35,300 1,000 247 7
M5   ... ... ... ... ... ... ... ... ... ... ... ... 100,000 2,830 618 17.5
M5.5 10000 ... ... ... ... ... ... ... ... ... ... ... ... 353,000 10,000 2,470 70
M6   ... ... ... ... ... ... ... ... ... ... ... ... 1,000,000 28,300 6,180 175
M6.5 100000 ... ... ... ... ... ... ... ... ... ... ... ... 3,530,000 100,000 24,700 700
M7 ... ... ... ... ... ... ... ... ... ... ... ... ... ... 10,000,000 283,000 61,800 1,750

ISO/TC209 (ISO 14644-1) Cleanness Class

Class Micro particle limit (grain/m3)
0.1μm 0.2μm 0.3μm 0.5μm 1.0μm
ISO 9 - - - 35,200,000 293,000
ISO 8 - - - 3,520,000 29,300
ISO 7 - - - 352,000 2,930
ISO 6 1,000,000 237,000 102,000 35,200 293
ISO 5 100,000 23,700 10,200 3,520 29
ISO 4 10,000 2,370 1,020 352 0
ISO 3 1,000 237 102 35 0
ISO 2 100 24 10 4 0
ISO 1 10 2 0 0 0

Comparison of ISO/TC209 and Fed.Std.209E

ISO/
TC209
Class
Fed.Std.209E Micro particle limit
English System
Class
SI system
Class
0.1μm grain/m3 0.5μm particle diameter
grain/m3 grain/m3
ISO 9 - - - - -
ISO 8 100,000 M6.5 - 100,000 3,520,000
ISO 7 10,000 M5.5 102,000 10,000 352,000
ISO 6 1,000 M4.5 10,200 1,000 35,200
ISO 5 100 M3.5 1,020 100 3520
ISO 4 10 M2.5 102 10 352
ISO 3 1 M1.5 10 1 34
ISO 2 - - 0 0 0
ISO 1 - - - 0 0

Environment of Cleamroom (ICR) and Disinfections (BCR)

American Federal Specifications 209B
Grade Minute particle (ICR) Organism particle (BCR) Illumination Relative humidity
Size (μm) (unit/ft3) unit/ Floating volume(unit/) Subside volume (unit/3 weeks) LUX % RH
100 0.5< 100> 3.5> 0.0035> 12,900< 1080
~
1620
45~40
10000 0.5<
5.0<
10000>
65>
350<
2.0>
0.0176< 64,600>
100000 0.5<
5.0<
100000>
700>
3500>
700>
0.0884< 323,000<
Fresh external air volume: 5~20% air blow or 30ft3 /min. people
Pressure mmAq: above 13 pressure difference +0.05
Temperature °F/°C: 72±5°F or 22.2±2.8°C
Airflow Aeration Count: Laminar flow way 0.45m/s±0.1m/s, air turbulence way over 28 counts/hr, ceiling height 8-12 feet.

Cause of cleanness declining

Causes Violation principle Description
1.HEPA broken A Check regularly as required
2.HEPA frame is not tight A Check regularly as required
3.HEPA pad deteriorated A Check regularly as required
4.Filter net is too dirty C.D Filter nets at different levels do not replace as required
5.Damper is blocked C.D Adjust switch because it looses by vibration
6.Air return mouth is block C.D Adjust the loose switch or blocked by interior apparatus
7.Duct leakage A When air blow is topped, particles may permeate to duct, from permeate to the indoor when air blow.
8.Fan belt is loose (broken) C.D Check the damage condition regularly
9.Ceiling material peel off B Check if there is corrosive gas in room
10.Ceiling gap is not sealed A Seal it, keep native pressure if necessary.
11.Place apparatus improperly C.D Hinder airflow, especially serious in one-way flow.
12.Change production process B.C Discuss to make improvement
13.Change partition C.D Chamber pressure and air volume do not change according.
14.Production facilities do not exhaust by force  D Exhaust duct is obstructed or air inhaling cover is poorly efficient, causing spreading.
15.Conveyer belt mouth permeated  A Directly link to non-control area, preferable to make room pressure difference larger or install more buffer area.
16.Door is open too long  A Air-lock door is not tight, causing improper air pressure.
17.Insufficient external air volume C.D Filter net of external air is dirty of or damper is blocked.
18.Improper wearing  A.B Human mistakes
19.Contaminated in-coming material  A Human mistakes
20.Contaminated supply air and polluted medicament  A Human mistakes
21.Cleaning &amp; maintenance is not done well  C.D Human mistakes
Note: A: No taking in B. No production C: No lingering D: Quick elimination
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