Table 2.
Decontamination Efficacy* and Relative Cleaning Effectiveness† of Cleaning Solutions on Biological Safety Cabinet Workbenches Intentionally Contaminated by a Predetermined Amount of Cyclophosphamide
| Cleaning Solution and Cleaning Session | Decontamination Efficacy (%) (mean ± SD) | Relative Cleaning Effectiveness† (%) (mean ± SD) |
|---|---|---|
| Quaternary ammonium (DR-100) | ||
| 1 | 98.710 ± 1.484 | 98.710 ± 1.483 |
| 2 | 99.938 ± 0.055 | 93.814 ± 2.070 |
| 3 | 99.989 ± 0.005 | 77.076 ± 13.951 |
| 4 | 99.996 ± 0.002 | 53.741 ± 25.344 |
| 5 | 99.997 ± 0.001 | 24.892 ± 15.577 |
|
| ||
| Sodium hypochlorite 0.02% (Zochlor) | ||
| 1 | 97.027 ± 1.596 | 97.027 ± 1.597 |
| 2 | 99.935 ± 0.042 | 97.933 ± 0.456 |
| 3 | 99.992 ± 0.003 | 84.150 ± 6.949 |
| 4 | 99.998 ± 0.002 | 67.167 ± 29.225 |
| 5 | 99.997 ± 0.001 | 3.151 ± 17.532 |
|
| ||
| Sodium hypochlorite 2% (Zochlor) | ||
| 1 | 98.008 ± 2.201 | 98.008 ± 2.201 |
| 2 | 99.935 ± 0.071 | 96.831 ± 2.893 |
| 3 | 99.992 ± 0.014 | 82.906 ± ND |
| 4 | 99.994 ± 0.011 | ND |
| 5 | 100.000 ± 0.000 | ND |
ND = not determined, SD = standard deviation.
*
Decontamination efficacy (DE, as %) was calculated for each cleaning solution as
DE = 100 − [(CP)M/(CP)T], where (CP)M = measured concentration of cyclophosphamide (pg/cm2) and (CP)T = theoretical concentration of cyclophosphamide (pg/cm2).
†
Relative cleaning effectiveness (RCE, as %) was calculated for each cleaning solution as RCE = 100 − [(q(cs+1)/q(cs)) × 100], where q is the measured quantity of cyclophosphamide on the workbench (pg) and cs is the cleaning session (1 ≤ n ≤ 5).