[quote=himanshumb]Dear Shahnawaz

thanks for your suggestion Thanks for your suggestion, I checked all the test what you were mention i.e. air velocity , air flow pattern and Diff. pressure and I got everything as per design criteria , my problem is from where I will start to calculate hold time &fh Value as I mention in my earlier mail I got different temperature range in same time say for example at time x I got in Channel1 – 256, ch-2-272, Ch3-248, ch-4-287, ch-5-291,ch-6-301,ch-7-310, and my acceptance criteria is 300 for 3 minutes , can I pass my validation test only base on FH value & 3 log reduction? Please help me on this issue.[/quote]

Dear Himanshumb,

The real concern in sterilzation/ depyrogenation is to achieve SAL, if your tunnel can acchieve 3 log reduction of CSE (Control Standard Endotoxin) and required Fh value then you can declair pass this tunnel.

At 250°C, the time required to disintegrate pyrogenes 1-log cycle, is 5

minutes (D-value). Empirically has been determined that for every 46.4°C.

increase in temperature, the D-value will be reduced by 1-log cycle.

In other words, at a temperature of 296.4°C, a 1-log pyrogene reduction is

accomplished after 30 seconds. At a temperature of 342.8°C., a 1-log

pyrogene reduction is accomplished after 3 seconds.

```
1-log cycle 2-log cycle 3-log cycle 4-log cycle
```

Z250 → D5min. D10min. D15min. D20min.

Z296.4 → D30sec. D60sec. D90sec. D120sec.

Z342.8 → D3sec. D6sec. D9sec. D12sec.

I think this will help you,

Thanks