Bilogical Indicators Exporation Date for Autoclave Studies

Hey Guys,

I’m in the process of requalifying a load on an porous load Autoclave at the moment and have discovered that the Biological Indicators that we have expire at the end of this month.

What I’m wondering is, if the cycle occurs on the 30th of this month (Which is the last scheduled cycle) is it ok is if part of the incubation period occurs after the expire date or does the incubation of the BI’s have to occur before the expire date.

I’ve looked at a HTM-2010, and a couple of other standard as well as the manufacturers specifications and none seem to state this. It just states do not use BI after the expiry date. Has anyone had any experience with this before?

Dear If you have the SOP to check the population of the BI Before every validation Run, & if it is as per the COA, Then there is no question of the expiry for the incubation & you can go ahead. But if you have not checked the population & if you come to know that it is expired, then you are not supposed to incubate the same.

Do not use does not allow for use (incubation) after end of expiration. Also, population check does not mean the BI is OK, many times it is the resistance that also may change and now you have a population with too low of an acceptable resistance. Population is not the critical factor, resistance is the critical aspect of a calibrated BI. Population may lower by 300% and overall lethality needed will change insignificantly. If resistance (D-Value) drops slightly, Fo to kill the same BI will be much less. Russ

My first thougths are doesn´t use these BI, but…in my company our Microbiology Departament can measure the real D-value of the BI…probably next time you can probe the BI spores survival, the D-value…
As a Engineer I prefer mathematically methods as F0 for probe the autoclaves, you can know the termocouples sensibility, accuracy, and you delete the error with the D-value determination in the BI.