Trouble shooting high yeast results in Air sampling

Hi!

We always have such great results for yeast and mould in the air. Just recently we had terrible results, with a lot of yeast. 

It seems so strange to me, anyone here that can help me with trouble shooting?

We use an air sampler. 

What is different?  Something has changed, different filters in HVAC, new supplier whose exterior packaging is dirty, PMs not being done as per schedule etc.

Investigate the changes and then repeat the sampling  (it could have also been that something touched the plates before sampling)

Hi!

We always have such great results for yeast and mould in the air. Just recently we had terrible results, with a lot of yeast. 

It seems so strange to me, anyone here that can help me with trouble shooting?

We use an air sampler. 

Hi AJL,

Can you quantify what you mean by "great", "terrible" results ?

How many samples ? duplicates ? Where ?

Maybe Winter is a-coming in? Condensation inc.

You can check if the sampler was clean as well prior to using. If you have many wet cleaning recently, it may impact really the results if there is no drying or possible ventilation.

Thanks, usually under 300cfu/M3.
Suddenly twice what we usually see.
We have had warm weather and a lot of wet cleaning lately. So it could be right.
Was just hoping I could find out if there were people who have experienced contamination from the sampler itself.

Hi AJL,

The top number seems to be in the ball-park area for dairy-type business.

Maybe try a few settle plates to see if similar trend observable ?

No direct personal usage but I could anticipate the specific sampling location/timing/activity might also be "sensitive" (reason I included the previous "duplicate" query).

At a past location also did air sampling twice a year at randomly picked dates.
Had great results until one year we didn't.

Found out that for some reason we always sampled a few weeks after our air-socks and condensers were deepcleaned.
Except for that year in which we did it before the deepclean.

Apparently our ''randomized dates''  weren't random enough.

But it did give us insight in that our cleaning intervals were just a little bit too long.

Thanks for that Marloes. Yeah our cleaning is twice a year, and I have only been collecting data for half a year. We could of course schedule the testing for after the cleaning. But that does seem a little bit like cheating

Hi AJL,

IMO it would be "logical" to -

(a) Test after cleaning as a possible reference condition.

(b) Compare Result for (a) with yr current "Procedure" (whatever that is ?).

The situation has some (sampling) similarities to that implemented for evaluation of the micro.status of food contact surfaces.

PS - Cleaning 2x a year !? Product for NASA ? :smile:

Hi Charles, thanks for the input. We are in the development phase with all the cleaning schedules, so they have been intentionally set to be a little stringent. 

Would you say once a year is sufficient or?

Hi Charles, thanks for the input. We are in the development phase with all the cleaning schedules, so they have been intentionally set to be a little stringent. 

Would you say once a year is sufficient or?

Hi AJL,

In ignorance of yr Process I offer the standard BRC response, should, minimally, be Risk-based.

For example, my experience with a significantly manual setup for raw/RTE seafood production demanded a cleanup of handling areas every day (eg night shift). Sometimes more than once due product variations. EMPG was originally done weekly and then frequency reduced based on results. Hence my surprise at your current routine.

But perhaps there is a reason/justification for yr, IMEX, unusually minimalist situation ?

Ah! I see there must be a misunderstanding. The cleaning I referred to was cleaning of the heating pump in the production area.
Of course cleaning in the general AREA and factory is daily.
I can see I have a tendency to forget important details.
The air sampling, is based on risk- basically as our product is enclosed for the majority of the time, counts in the air do not pose a risk to product.
But as I have set an upper limit of 300cfu/g mould - of course we should adhere to it.
I was hoping actually that it could have been due to an analysis error- because both of our sites unfortunately had the same high counts and the colonies were similar in appearance

Hi AJL,

Thks for the clarification.

 I deduce that you sample various locations and that this one particular area is atypical ? By a large amount ? (No experience with Y&M but colony counts IMEX invariably show considerable variation, eg +/- 50%).

I should have previously enquired as to yr target value for "APC" counts cfu/m3 and whether these showed similar change as to yeast values ?

I daresay you have already seen the compilation at following link, notably excel sheet1 and file sh1 -

https://www.ifsqn.co...ent/#entry81054

From a little searching this topic has been substantially investigated in the Literature over last 40 years or so although the recurring comment is that results can vary enormously between plants due a variety of (different) causes. Here is a (2008) summary of some possible sources and remedies -

Control Airborne Contamination.pdf   545.88KB   17 downloads

I particularly noticed a caution regarding humidity and a plaudit to HEPA filters, eg -

HEPA effect.PNG   16.31KB   0 downloads

(also see the file sh8 in link above)

This table illustrates the air contamination impact of varying levels of bacteria and yeast/mould -

Air Contamination Levels vs cfu vs Yeast Ranges.pdf   120.75KB   20 downloads

Based on the above observations and available data such as in the attachments below, yr target yeast level should possibly be lowered since yr process seems substantially automated. (cf APHA's [stricter] APC target of <90cfu/m3).

Air Quality in Dairy Plant.pdf   243.51KB   9 downloads

Air Qualty in Meat,Dairy Plants (2).pdf   584.18KB   7 downloads

PS - After wading through all the above complexities, here is an ultra-stripped down solution which is attractive if only for its simplicity. :smile:

Monitoring Microorganisms in a Food Plant.pdf   279.79KB   24 downloads