Regarding terminal Sterilizer


We r validate the terminal Sterilizer (Super Heated Water Shower) at two temperature 106.1 for LDPE vials & 121.1 for PP vials. That is why we are using B.subtillis. I want to know that can I calculate the Fo value or not. is it required or not. i am giving the BI indicator details below…

B.subtillis (at 106 degree)
Z value-7.2
D value- 11.3 min

then we are going for 91 min at 106.1 for 8 log reduction by using the calculation.

8 Log reduction = D value at 106 x 8
= 11.3 x 8
=90.4 min.

Fo value is required or only on the basis of hold time & BI indicator sterility assurance we can released our terminal sterilizer for routine purpose.

please suggested me

Mahak Singh
Executive : QA Validation
Promed Exports Pvt. Ltd.
Nalagarh (H.P.)

Dear Mahak,
For 121.1°C cycle , you should use B.Stereothermophilis (BI) as biological indicator, and you must calculate F subo value at cold spot not theoritically but practically. For applying over kill approach you can use extended cycle instead of theoritical calculated value.

Thanks and best regards,