| Class | US FED STD 209E Maximum Particles/ft³ | ISO equivalent | ||||
| >0.1 um | >0.2 um | >0.3 um | >0.5 um | >5 um | ||
| 100 | 100 | ISO5 | ||||
| 1000 | 1000 | 7 | ISO6 | |||
| 10,000 | 10,000 | 70 | ISO7 | |||
| 100,000 | 100,000 | 700 | ISO8 | |||
ISO 14644-1 Cleanroom Standards
| Class | Maximum Particles/m³ | FED STD 209E equivalent | |||||
| >0.1 um | >0.2 um | >0.3 um | >0.5 um | >1 um | >5 um | ||
| ISO 5 | 100,000 | 23,7000 | 102,000 | 3,520 | 8,320 | 293 | Class 100 |
| ISO 6 | 1,000,000 | 237,000 | 102,000 | 35,200 | 8,320 | 2,930 | Class1,000 |
| ISO 7 | 352,000 | 83,200 | 2,930 | Class 10,000 | |||
| ISO 8 | 3,520,000 | 832,000 | 29,300 | Class 100,000 | |||
| ISO 9 | 35,200,000 | 8,320,000 | 293,000 | Room Air | |||
| Criteria | Class 100 ISO5 | Class 1000 ISO6 | Class 10,000 ISO7 | Class 100,000 ISO8 |
| Air changes per HR/Min | 300 to 480 / 5 to 8 | 180 / 3 | 60 /1 | 20 /0.33 |
| Filter coverage % | 60 – 70 | 20 – 30 | 7 – 15 | 4 – 5 |
| CFM per square foot | 36 – 65 | 18 – 32 | 9 – 16 | 4 – 8 |
| Filter Efficiency | 99.997% HEPAs | 99.997% HEPAs | 99.997% HEPAs | 99.97% HEPAs |
| Ceiling Type | Aluminum T-bar grid | Aluminum T-bar grid | Conventional T-bar grid | Conventional T-bar grid |
| Light Fixture type | Tear drop or 2’x4’ cleanroom fixture | 2’x4’ cleanroom fixture | 2’x4’ cleanroom fixture | 2’x4’ standard fixture |
| Ceiling Panel | FRP, Vinyl rock or Mylar | Vinyl rock or Mylar | Vinyl rock or Mylar | Vinyl rock or Mylar |
| Wall System | Modular or standard built | Modular or standard built | Modular or drywall | Modular or drywall |
| Flooring cover | Welded sheet vinyl or Epoxy | Welded Sheet vinyl or Epoxy | Sheet vinyl or VCT | Sheet vinyl or VCT |
| Flooring base | Cove or Aluminum base channel | Cove or Aluminum base channel | Cove or Aluminum base channel | Cove or Aluminum base channel |
| Air Returns | Low wall on long axis | Low wall at perimeter | Low wall | Low wall or ceiling |