Clean Rooms - Federal Standard 209
Clean room maintained virtually free of contaminants like dust or bacteria are required for types of laboratory work and in the production of electronic and aerospace equipment precision parts.
The air quality for clean rooms are described in Federal Standard 209 "Airborne Particulate Cleanliness Classes in Clean Rooms and Clean Zones" (A through D) where classes are named after the maximum number of particles of 0.5 micrometers or more in diameter which is acceptable in the air.
| Class | Maximum Number of Particles in Air (particles per cubic foot air) | ||||
|---|---|---|---|---|---|
| Particle Size | |||||
| 0.1 μm | 0.2 μm | 0.3 μm | 0.5 μm | 5.0 μm | |
| 1 | 35 | 7.5 | 3 | 1 | |
| 10 | 350 | 75 | 30 | 10 | |
| 100 | 750 | 300 | 100 | ||
| 1000 | 1000 | 7 | |||
| 10000 | 10000 | 70 | |||
| 100000 | 100000 | 700 | |||
In a clean room rated as "Class 10000" there may not exists more than 10000 particles larger than 0.5 microns in a cubic foot of air.
Classes and their Typical Uses
- Class 1 & 10 - production laboratories for electronic integrated circuits ..
- Class 100 - production areas for photo labs, medical implants ..
- Class 10000 - production locales for TV tubes, hospital operating theaters ...
- Class 100000 - production of ball bearings
Federal Standard 209 E uses metric units and the classes are defined as:
For full table - rotate the screen!
| Class | Maximum Number of Particles in Air (particles per volume unit) | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Particle Size | |||||||||||
| 0.1 μm | 0.2 μm | 0.3 μm | 0.5 μm | 5 μm | |||||||
| SI | English | (m3) | (ft3) | (m3) | (ft3) | (m3) | (ft3) | (m3) | (ft3) | (m3) | (ft3) |
| M 1 | 350 | 9.91 | 75.7 | 2.14 | 30.9 | 0.875 | 10.0 | 0.283 | |||
| M 1.5 | 1 | 1240 | 35.0 | 265 | 7.50 | 106 | 3.00 | 35.3 | 1.00 | ||
| M 2 | 3500 | 99.1 | 757 | 21.4 | 309 | 8.75 | 100 | 2.83 | |||
| M 2.5 | 10 | 12400 | 350 | 2650 | 75.0 | 1060 | 30.0 | 353 | 10.0 | ||
| M 3 | 35000 | 991 | 7570 | 214 | 3090 | 87.5 | 1000 | 28.3 | |||
| M 3.5 | 100 | 26500 | 750 | 10600 | 300 | 3530 | 100 | ||||
| M 4 | 75700 | 2140 | 30900 | 875 | 10000 | 283 | |||||
| M 4.5 | 1000 | 35300 | 1000 | 247 | 7.00 | ||||||
| M 5 | 100000 | 2830 | 618 | 17.5 | |||||||
| M 5.5 | 10000 | 353000 | 10000 | 2470 | 70.0 | ||||||
| M 6 | 1000000 | 28300 | 6180 | 175 | |||||||
| M 6.5 | 100000 | 3350000 | 100000 | 24700 | 700 | ||||||
| M 7 | 10000000 | 283000 | 61800 | 1750 | |||||||
Note! Federal Standard 209E is canceled and superseded by International Organization for Standardization (ISO) Standards - International Standards for Clean Rooms and associated controlled environments, ISO 14644.
Related Topics
• Ventilation Systems
Design of systems for ventilation and air handling - air change rates, ducts and pressure drops, charts and diagrams and more.
Related Documents
Clean Rooms - ISO Standard 14644
Clean room class limits according ISO Standard 14644-1.
Mesh Sizes vs. Particle Diameters
Strainers and filters - mesh size vs. particle diameter opening size.
Particle Sizes
The size of dust particles, pollen, bacteria, virus and many more.
Parts per Million - ppm
ppm - or parts per million - is commonly used as a unit of concentration.
Ventilation Principles
Some commonly used ventilation principles - short cut, mixed air, displacement and piston principle.