Table 3. Contamination rate in plates in group A.
| low | medium | high | |
| water outlet | 5 | 5 | 0 | 
| air outlet | 10 | 0 | 0 | 
low: cfu<10 and 10
medium: 10<cfu<100
high: 100 and more
than 100
| low | medium | high | |
| water outlet | 5 | 5 | 0 | 
| air outlet | 10 | 0 | 0 | 
low: cfu<10 and 10
medium: 10<cfu<100
high: 100 and more
than 100