Table 2.
Humidity effect on total and respirable dustiness for select materials. Mean values and standard deviations are provided.
| Relative humidity (%) | 20 | 50 | 80 | |||
|---|---|---|---|---|---|---|
| Dustiness | D tot (%) | D resp (%) | D tot (%) | D resp (%) | D tot (%) | D resp (%) |
| Powder | Mean (SD) | Mean (SD) | Mean (SD) | Mean (SD) | Mean (SD) | Mean (SD). |
| Aeroxide P25 TiO2 | 9.5 (4.9) | 6.3 (1.8) | 15.7 (5.1) | 7.2 (2.1) | 13.5 (2.3) | 6.0 (1.1) |
| Aerosil OX 50 SiO2 | 2.5 (1.4) | 1.9 (0.7) | 3.0 (0.1) | 1.5 (0.1) | 3.0 (0.6) | 1.8 (0.4) |
| HSL CeO2 | 4.9 (2.0) | 2.7 (0.3) | 5.8 (0.3) | 2.8 (0.3) | 5.8 (1.8) | 1.6 (1.1) |
| AZ road dust (SiO2) | 7.4 (0.4) | 4.2 (0.2) | 7.7 (1.5) | 3.9 (0.8) | 7.3 (3.5) | 4.0 (2.9) |
| Microgrit CeO2 | 6.5 (0.5) | 3.5 (0.5) | 6.5 (2.2) | 2.6 (0.8) | 1.2 (0.4) | 0.4 (0.1) |
| Microgrit SiC | — | — | 27.4 (1.0) | 9.6 (0.3) | 25.3 (9.8) | 9.6 (0.9) |
| PGN nanoclay | 2.9 (0.1) | 0.5 (0.1) | 3.9 (1.2) | 0.8 (0.3) | 3.7 (1.9) | 0.3 (0) |
| Printex 90 carbon | 31.9 (1.8) | 13.5 (0.2) | 30.9 (3.1) | 12.9 (1.4) | 30.2 (1.5) | 10.6 (1.3) |
| Sucrosea | 0.1 (0.0) | 0.3 (0.0) | — | — | — | — |
aSucrose: deliquescent for relative humidity at 50% and greater.