Mold Limits for Microbiology Testing

[tammyfromri]

Hello all,

I have a Class 7 / 10,000 (Grade C) CER. We have recently had some issues with mold showing up in our microbiology reports as follows:

- 03/28/20: 2 CFU / 1 mold at both 30-35 and 20-25 Celsius (C) on settling plate in gowning room
- 07/29/20: 20 CFU / 1 mold at both 30-35 and 20-25 C on surface contact
12 CFU / 1 mold at both 30-35 and 20-25 C settling plates in gowning room
- 10/10/20: No mold found
- 12/02/20: 0 CFU at 30-35 C and 2 CFU / 1 mold at 20-25 C on airflow in pass thru room
4 CFU at 30-35 C and 4 CFU / 1 mold at 20-25 C on surface contact in pass thru room
0 CFU at 30-35 C and 1 mold on airflow in ultrasonic cleaning room
0 CFU at 30-35 C and 1 CFU / 6 mold on airflow in gowning room
1 CFU at 30-35 C and 1 CFU / 1 mold settling plates in gowning room
3 CFU at 30-35 C and 4 CFU / 1 mold at 20-25 C on settling plates in gowning room
17 CFU at 30-35 C and 21 CFU / 1 mold at 20-25 C in manufacturing area
- 03/09/21: No mold found

We have never come across mold before. We typically range from 0 to 25 or so CFU accross the board in airflow, surface contact and settling plates in the pass thru, gowning, and ultra sonic cleaning rooms. The main manufacturing area ranges between 0 and 12 CFU with the 21 CFU above being rare. We did a complete excursion at first finding of the mold but still continue to have the issue intermittently, never in the same location. I have assessed risk saying that EO and/or Gamma sterilization is sufficient to kill any mold present and that in fact mold is easier to kill than bacteria.

Questions:

1. Are we able to write a justification why low levels of mold are ok? It seems like the mold is sporadic with us, some months it’s there and some it’s not.

2) We have nothing written into our Environmental Testing procedure about mold limits. What are acceptable mold limits?

For those reading this I thank you so much for your time and consideration.

Have a great day and stay safe!
Tammy

 

[indubioush]

How much monitoring data did you have without mold? Was there years with no mold and then it showed up, or is this a recent clean room installation? The levels you presented are not too concerning in my opinion; however, if there was a definite point in time where you had no mold for years and now you see it, I would want to find out the issue as well. I would check your HVAC and air systems. Also, look back at your monitoring reports. Was the negative control completely clean? Did your agar media change. Did your test lab change?
If you see the mold again, it may be wise to get the mold identified so you know what it is and confirm that the organism is easily sterilized.

 

[tammyfromri]

This is a well established CER since 2006. We started getting very minor mold issues (1 mold mostly in ancillary rooms) back the end of 2019. The place that does our microbiology testing is a division of our sterilizer. They said the particular mold found is easily killed by EO sterlization; that is is actually easier to kill than bacteria. We have cleaned, changed filters, etc some months it is there and some months it isn't.

I want to put a limit in my procedure but cannot find anywhere anything that says what is acceptable or unacceptable. Looking for direction on that.

 

[indubioush]

I want to put a limit in my procedure but cannot find anywhere anything that says what is acceptable or unacceptable. Looking for direction on that.

It is up to you to determine this based on risk per ISO 14698-1.