TABLE 3.
Summary of log reduction in viable spores as a function of exposure to 3,000 ppmv of CD gas
| CT (ppmv-h) | Log reduction (avg ± SD) in no. of viable spores by material typea |
|||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Carpet |
Ceiling tile |
Cinder block |
I-beam steel |
Wallboard |
Wood |
|||||||
| CSI | Sabre | CSI | Sabre | CSI | Sabre | CSI | Sabre | CSI | Sabre | CSI | Sabre | |
| 1,500 | NT | 5.6 ± 1.3 | NT | 2.6 ± 0.4 | NT | 5.2 ± 1.7 | NT | 3.4 ± 1.2 | NT | 2.7 ± 0.6 | NT | 1.7 ± 0.5 |
| 3,000 | 6.8 ± 0.5 | 6.6 ± 0.5 | 3.6 ± 0.3 | 3.7 ± 0.9 | 6.8 ± 0.2 | 5.7 ± 1.1 | 6.2 ± 1.1 | 5.1 ± 1.4 | 5.4 ± 1.3 | 3.7 ± 1.3 | 2.9 ± 0.8 | 2.0 ± 0.6 |
| 6,000 | NT | 6.7 ± 0.3 | NT | 4.5 ± 0.4 | NT | 6.1 ± 0.9 | NT | 5.9 ± 1.0 | NT | 5.6 ± 1.0 | NT | 3.2 ± 0.7 |
| 9,000 | 7.0 ± 0.2 | 6.7 ± 0.3 | 6.6 ± 0.7 | 5.5 ± 1.1 | 6.8 ± 0.2 | 6.3 ± 0.6 | 7.1 ± 0.2 | 5.7 ± 1.3 | 7.0 ± 0.4 | 5.8 ± 1.1 | 5.0 ± 1.6 | 4.1 ± 1.6 |
| 15,000 | 7.0 ± 0.2 | 6.7 ± 0.3 | 7.2 ± 0.2 | 6.5 ± 0.6 | 6.7 ± 0.3 | 6.4 ± 0.4 | 7.1 ± 0.3 | 6.7 ± 0.5 | 7.1 ± 0.3 | 6.2 ± 0.7 | 6.9 ± 0.5 | 4.9 ± 1.6 |
| 21,000 | 7.0 ± 0.2 | 6.7 ± 0.3 | 7.2 ± 0.2 | 6.7 ± 0.5 | 6.8 ± 0.2 | 6.4 ± 0.4 | 7.1 ± 0.2 | 6.9 ± 0.3 | 6.7 ± 0.8 | 6.3 ± 0.6 | 7.0 ± 0.2 | 5.9 ± 1.2 |
| 27,000 | 7.0 ± 0.2 | 6.7 ± 0.3 | 7.2 ± 0.2 | 6.9 ± 0.2 | 6.8 ± 0.2 | 6.4 ± 0.4 | 6.9 ± 0.8 | 6.9 ± 0.3 | 6.8 ± 0.8 | 6.1 ± 0.9 | 7.0 ± 0.2 | 6.6 ± 0.4 |
| PCb | 7.0 ± 0.2 | 6.7 ± 0.3 | 7.2 ± 0.2 | 6.9 ± 0.2 | 6.8 ± 0.2 | 6.4 ± 0.4 | 7.1 ± 0.2 | 6.9 ± 0.3 | 7.1 ± 0.3 | 6.5 ± 0.5 | 7.0 ± 0.2 | 6.6 ± 0.4 |
Inoculated coupons were exposed to either CSI or Sabre CD gas at 3,000 ppmv for a period of 0.5, 1, 2, 3, 5, 7, or 9 h and viable spores were extracted from building materials as detailed in Materials and Methods. Values highlighted in boldface indicate complete kill, based on pour-plating data of the one-third fraction (detection limit of approximately 5 to 10 viable spores per sample). NT, not tested.
PC, positive control. Values represent the average (with SD) of the log number of recovered spores from all positive controls of each material type. This value is used to calculate the log reduction by subtracting the average log number of viable spores recovered from the replicate coupons of each material type at each CT value.