TABLE I.
Filter-based air samples: concentration of amorphous silica (PVC filters)
| Sample Type (mg/m3) |
Sampling Location Average Flow Rate (L/min) |
Process/Task Air Volume (L) |
Total Time Sampled (min) Total ConcentrationA |
||||
|---|---|---|---|---|---|---|---|
| Task Area | WWT | 3ft from filter change task | 36 | 6.03 | 217 | NDB | |
| Background | WWT | on cart, 20ft from task area | 333 | 5.99 | 1,995 | ND | |
| PBZ | WWT | filter changes | 39 | 5.97 | 233 | ND | |
| PBZ | Subfab | tank change; mock-up replenish batch | 22 | 5.99 | 132 | ND | |
| Task Area | Subfab ND | changing tanks and replenishing batch | 29 | 6.11 | 177 | ||
| Background | Subfab | 15ft from tanks | 189 | 5.40 | 1,021 | ND | |
| PBZ | WWT | filter and pre-filter change of acid tank | 33 | 6.11 | 200 | ND | |
| Task Area | WWT | filter and pre-filter change of acid tank | 37 | 6.04 | 225 | ND | |
| PBZ | Cleanroom | set-up of CMP tool | 25 | 6.04 | 151 | ND | |
| Task Area | Cleanroom ND | on workstation operator’s table near CMP tool | 45 | 6.04 | 273 | ||
| Background | Cleanroom | 5ft from CMP tool | 209 | 5.64 | 1,167 | ND | |
| Task Area | Subfab | 2ft from slurry system | 19 | 6.02 | 115 | 0.497C | |
A
No sample results yielded sufficient particulate to be sent for analysis of amorphous silica content.
B
ND = Non-detectable.
C
Value is between the limit of detection (50μg/sample) and the limit of quantification (180μg/sample); estimated result.