Surface bioburden determined by total immersion and contact plates after disinfection (for clarification see text)
| Plastic ampoules | Glass ampoules | Injection vials | ||||
| TI | CP | TI | CP | TI | CP | |
| n | 10 | 40 | 10 | 30 | 10 | 30 |
| Positive | 4 | 1 | 5 | 6 | 10 | 3 |
| Negative | 6 | 39 | 5 | 24 | 0 | 27 |
| Mean cfu | 1.60 | 0.03 | 0.70 | 0.20 | 6.20 | 0.13 |
| Contaminated (%) | 40 | 2.5 | 50 | 20 | 100 | 10 |
CP, contact plate; n, number of samples examined; negative, number of samples without growth; positive, number of samples with ≥1 cfu; TI, total immersion.