Autoclave PQ - Uniformity of 2C

USFDA · July 25, 2011, 1:37pm

All,
Can some one help me in finding the original source for the following requirement that is often mentioned in white papers for autoclave validation?

“A temperature uniformity of ≤ 2.0°C from average is maintained after probes reach sterilization temperature.”

Thanks
USFDA

Enrique_Riis · July 28, 2011, 9:31am

USFDA,

I am not sure that it is the original source, however, the temperature uniformity requirement of ≤ 2.0°C is mentioned in:

EN 285:2009, pp. 24-25, section 8.2.
ISO 17665-2:2009, p. 22, section A.4.

I hope this is useful.

Best regards,

Enrique Riis

USFDA · July 28, 2011, 1:18pm

Hi Enrique Riis,

Thanks for the references.

I was able to look in to the old HTM 2010 Part 3 where in on page 63 it said

“the temperature measured in each load item does not fluctuate
more than ± 1 º C, and does not differ from that in other load items
by more than 2 º C”.

So the specific thing I was looking for 2 or 2.0 as my results match with 2.0 but the PQ said 2.

The EN and ISO references were not available for free. May I request you to post the specific line or lines from these standards.

This is the first time I posted a question here and I am happy that I got a useful info and timely response. I hope to reciprocate the same to others here by checking this site frequently.

USFDA

Enrique_Riis · August 1, 2011, 7:20am

I am glad I could help.

These are the specific lines.

EN 285:2009, pp. 24-25, section 8.2.: "Throughout the holding time the temperature measured at the reference measurement point of the sterilizer chamber, any temperature measured within the test pack and the saturated steam temperature calculated from the measured chamber pressure shall:

be within the sterilization band;
not differ from another by more than 2 ºC.

ISO 17665-2:2009, p. 22, section A.4.: " Throughout the holding time the temperature measured at the reference measurement point of the sterilizer chamber, any temperature measured at the same instant within the test pack and the respective saturated steam temperature calculated from the chamber pressure should be within the sterilization temperature band and not differ from each other by more than 2 ºC.