Cleanroom gloves look a lot like exam gloves. They’re available in nitrile, latex or vinyl materials. They’re thin, ambidextrous and disposable. But they have something extra – an ISO number or Class number. What does this mean?
To understand cleanroom gloves, we need to understand why they are needed. A “cleanroom” is an environment with a controlled level of contamination – dust, microbes and aerosol particles – to prevent damage to a product during manufacturing. Think microelectronics, semiconductors, and biotechnology, where a particle 200 times smaller than a human hair can lead to expensive failures and downtime.
Cleanroom contamination is measured by the number of particles by volume of air at a particular particle size. The air you breath contains about 35 million particles sized 0.5 µm and larger per cubic meter. The air in a cleanroom will have much less, making the environment “cleaner.”
The First Cleanroom Standards
US FED STD 209E set the first cleanroom standards. Airborne contaminates were measured as maximum particles per cubic foot. So a “Class 100” environment meant there was an upper limit of 100 particles/ft3, size 5 µm or smaller. A “Class 10” meant no more than 10 particles/ft3.
| US FED STD 209E Cleanroom Standards |
||||||
|---|---|---|---|---|---|---|
| Class | maximum particles/ft3 | ISO equivalent |
||||
| ≥0.1 µm | ≥0.2 µm | ≥0.3 µm | ≥0.5 µm | ≥5 µm | ||
| 1 | 35 | 7.5 | 3 | 1 | 0.007 | ISO 3 |
| 10 | 350 | 75 | 30 | 10 | 0.07 | ISO 4 |
| 100 | 3,500 | 750 | 300 | 100 | 0.7 | ISO 5 |
| 1,000 | 35,000 | 7,500 | 3000 | 1,000 | 7 | ISO 6 |
| 10,000 | 350,000 | 75,000 | 30,000 | 10,000 | 70 | ISO 7 |
| 100,000 | 3.5×106 | 750,000 | 300,000 | 100,000 | 700 | ISO 8 |
The New Standard
In 1999, the US Department of Commerce introduced a new classification system called ISO 14644-1. This document established the certification requirements for air cleanliness areas, and airborne particulates are measured as particles per cubic meter rather than cubic foot. So a Class 100 became ISO 5, and a Class 10 became ISO 4. While this new standard officially replaced the old Federal Standard 209-e in 2001, both classification terms are still in use.
| ISO 14644-1 Cleanroom Standards | |||||||
|---|---|---|---|---|---|---|---|
| Class | maximum particles/m3 | FED STD 209E equivalent |
|||||
| ≥0.1 µm | ≥0.2 µm | ≥0.3 µm | ≥0.5 µm | ≥1 µm | ≥5 µm | ||
| ISO 1 | 10 | 2.37 | 1.02 | 0.35 | 0.083 | 0.0029 | |
| ISO 2 | 100 | 23.7 | 10.2 | 3.5 | 0.83 | 0.029 | |
| ISO 3 | 1,000 | 237 | 102 | 35 | 8.3 | 0.29 | Class 1 |
| ISO 4 | 10,000 | 2,370 | 1,020 | 352 | 83 | 2.9 | Class 10 |
| ISO 5 | 100,000 | 23,700 | 10,200 | 3,520 | 832 | 29 | Class 100 |
| ISO 6 | 1.0×106 | 237,000 | 102,000 | 35,200 | 8,320 | 293 | Class 1,000 |
| ISO 7 | 1.0×107 | 2.37×106 | 1,020,000 | 352,000 | 83,200 | 2,930 | Class 10,000 |
| ISO 8 | 1.0×108 | 2.37×107 | 1.02×107 | 3,520,000 | 832,000 | 29,300 | Class 100,000 |
| ISO 9 | 1.0×109 | 2.37×108 | 1.02×108 | 35,200,000 | 8,320,000 | 293,000 | Room air |
Glove Classifications
While there are no published standards that designate gloves as “ISO 5,” for instance, glove manufacturers understand the importance of maintaining specified particulate levels in cleanrooms. Gloves are carefully laundered, dried, tested and packaged to ensure a particle count that is compatible with the cleanroom environment where they will be used. So a glove listed as Clean Class 10 or ISO 4 is compatible with a Class 4 cleanroom and up. A “Controlled Environment” or Clean Class 1000 glove is suitable for ISO 6 and up environments.
