8 replies to this topic

[qualita2]

Hello everyone! It's the first time I write here.

I would like to ask advise on possible treatments for ambient air against molds.

 

We find presence in the final product (cereal products with aw < 0,3 and RU < 10%), usually around 40 UFC/g.

Last analysis on air showed > 300 UFC/m3.

We are going to make some structural changes (eg. air treatment unit, that now we don't have), but in the meantime we need to make a cleaning treatment.

 

We don't want to use phenols.

Do you have something to suggest?

Thanks in advance 

 

Claudia

[Evans X.]

Greetings Claudia,

 

To setup a cleaning plan for molds you should start with discussing it with your cleaning agents supplier, for suggesting the best product for the task. It is them who you can also tell to suggest you something without phenols.

Mold cleaning usually involves a foaming agent which will be sprayed on the surfaces, followed by a lot and thorough scrubing and then rinsing with a high pressure water machine. Depending on the supplier's instructions it may need to be repeated a couple of times or even apply a complementary cleaning agent.

Scrubing and high pressure rinsing though are a must for molds.

 

Regards!

[qualita2]

Hi Evans and thanks for the reply. 

As I wrote, the contamination for us is primarily in the ambient air of the production area.

We have used a fumigant containing 2-phenylphenol, which was effective but had a problem of residues in the final product.

That's why we are searching for something different, which could be also fumigants or a different technique.

I hope now the situation is clearer.

 

Claudia

[Evans X.]

Hello Claudia,

 

I saw in your first post about the ambient air, but this is not the actual source. The contamination derives from the spores released by the mycelial growth. So there are three cases this can happen.

1) The less likely is the incoming air from outside, so you will need ways to stop the air flow.

2) Another possibility could be your raw material having a high mold concentration which could, through airflows, reach the production line or storage facilities.

3) The most propable cause can be from molds formed inside the facility which are left quite unchecked and so they have reached the point of forming spores which are released in the air.

 

That is why I suggested the throrough cleaning of the facility's surfaces (walls, roof, drains, window cases etc). Fumigation may solve the problem temporarily, but it will not stop the next spore release cycle and it actually comes after the physical cleaning to destroy any remnants in the air.

[qualita2]

Thanks again for your reply, Evans.

Regarding the 3 cases you have mentioned:

 

1) The less likely is the incoming air from outside, so you will need ways to stop the air flow.   

We are working on this.

 

 

2) Another possibility could be your raw material having a high mold concentration which could, through airflows, reach the production line or storage facilities.

Actually this is possible, we have to check.

 

 

3) The most propable cause can be from molds formed inside the facility which are left quite unchecked and so they have reached the point of forming spores which are released in the air.

During last April-July, the entire production line has been disassembled, cleaned (also with NaOH) and reassembled. We have also cleaned the roof and the walls, which we have also painted.

There is no visible sign of molds in the facility, but maybe it's hiding somewhere...

 

All this to say that I know we have to work on differents issues. The treatment would be only to keep the problem at low level while we fix all the other things.

 

 

Claudia

[Rick Reyes]

Good afternoon qualita2, just a small note here, you listed that you cleaned all production equipment and structures using NaOH (sodium hydroxide), while it is a powerful cleaning chemical the appropriate chemical to mitigate mold and spores is NaOCl (Sodium hypochlorite) (bleach). Sodium Hydroxide is much less effective at destroying the structures of molds and spores unless you can somehow add heat to the process. All airborne molds that are not related to an outside air source are sourced from a contamination source on some surface, you are better advised to find the root cause and eliminate it than to focus on the air itself. I have been in the food processing industry for almost 40 years and I can tell you that this could be a timely process but really the only real way to fix the problem.

On another note, the use of high pressure in mold mitigation will only further complicate your issues since high pressure will aerosolize not only the molds and spores but things like listeria from surfaces that are not typically food contact surfaces.

Good luck with your efforts.

[qualita2]

Good morning Rick,

Thankyou very much for your answer. 

Sodium Hydroxide was chosen for other reasons (not intenionally to eliminate molds).

We are going to do all the things suggested. I hope we will find the root cause!

[G M]

Good afternoon qualita2, just a small note here, you listed that you cleaned all production equipment and structures using NaOH (sodium hydroxide), while it is a powerful cleaning chemical the appropriate chemical to mitigate mold and spores is NaOCl (Sodium hypochlorite) (bleach). ...

 

I was looking into broadcast treatments for new construction and saw a fair bit of literature pointing to peroxyacetic acid as a good suppressant for these sorts of things as well.

 

As others have mentioned though, treating the air is just a bandage for the symptom and not going to fix the underlying harborage points in the facility that are dispersing these spores.  

 

 

 

...

During last April-July, the entire production line has been disassembled, cleaned (also with NaOH) and reassembled. We have also cleaned the roof and the walls, which we have also painted.

There is no visible sign of molds in the facility, but maybe it's hiding somewhere...

...

 

Yes, it probably is "hiding somewhere".  Do you regularly clean the ceiling and overhead utilities, or was that a one-off?  You mention painting, what is the wall and ceiling material under the paint?

 

I then have to wonder what is protecting you from flaking paint.

[Charles.C]

Hi Claudia,

 

Might have helped if you had initially described what kind of Process involved.

 

You clearly need some data regarding mould levels on "Process" materials/Surfaces.

 

Another option could be to ask the company who provided yr air data (I assume non-internal measurement) to suggest/investigate root causes. I anticipate this is a part of their package offer.