APC Counts Increased After Sanitation

Our monthly environmental monitoring swabs included pre and post sanitation swabs of the same spots (zone 3). 

The APC counts were <10 before sanitation and they increased substantially (3000 CFU) after.

Any help for figuring out why something like this could have happened would be greatly appreciated!

Thank you!

Our monthly environmental monitoring swabs included pre and post sanitation swabs of the same spots (zone 3). 

 

The APC counts were <10 before sanitation and they increased substantially (3000 CFU) after.

 

Any help for figuring out why something like this could have happened would be greatly appreciated!

Thank you!

Hi GQS,

There are so many possibilities !

I'm afraid you will first need to supply some context to your query regarding the products/process/sampling/analytical methodology(s).

Hi Charles,

Thanks for your reply.

The swabs were taken from a piece of stainless steel equipment (non-food contact) by using sponges and sending to external lab. We sent swabs of the same spots before and after cleaning with detergent (2-butoxy-ethanol, potassium hydroxide, tetrasodium EDTA) and rinsing. 

Let me know if you still need more context.

Hi Charles,

 

Thanks for your reply.

 

The swabs were taken from a piece of stainless steel equipment (non-food contact) by using sponges and sending to external lab. We sent swabs of the same spots before and after cleaning with detergent (2-butoxy-ethanol, potassium hydroxide, tetrasodium EDTA) and rinsing. 

 

Let me know if you still need more context.

Hi GQS,

Thks for info.

Some more queries -

(1) How many total samples/sampling points routinely involved in each sampling / transmission to lab ?

(2) How many individual sampling points/samples/values associated with yr "3000" comment ? (I am hoping there were some duplicates involved).

(3) Sampling/rinsing procedures/transmission/personnel etc any changes  ?

(4) Same lab throughout ?

(5) Area swabbed ? Commercial Kit used ?

(6) Only measured the APC ?

My guess is that sanitation sprayed material from food contact sources onto the area in question during their process and it didn't get the same attention 

Was the surface dry or wet when swabbed? this could affect the results.

I've had that happen many times.  Never could figure out WHY.

One day, I swabbed a stainless scale platform.  Results were high.  Sanitized and reswabbed, even higher.  Got a brand new roll of paper towel, fresh sanitizer, cleaned again.  Even higher. Got sanitizer from a different area of the plant, recleaned.  Still higher.
Sprayed scale platform with bleach.  Numbers dropped to 0.

Poor / inconsistent sanitation leading to biofilms. Or, poor sanitation practices leading to overspray or aerosolizing of dirty stuff onto cleaned surfaces.

Try taking a swab sample after cleaning, before sanitizing and then another one after sanitizing to see if that had any effect. You really should get zero APC on a smooth, impermeable surface after cleaning before using sanitizer.

Sometimes the way sanitizers are applied stuff tends to show up.

Hi, Gelato.

I supposed the inquiry is for Ice cream plant. You could also look check in reverse or isolate the issue..

1. When you perform pre-cleaning test, how long is the time for cleaning?

2. Is the post-cleaning sampling waited so the samples are sent as one?

3. How long is the sample being stored, sent and analyze?

The reason for the above is the post cleaning "could be" the accurate one and the microbes being sampled for pre-cleaning may not be handled ideally to preserve the sample.

4. How is the start-up products microbial profile? Are they within norms?

The reason being for dirty equipment (assuming this the one that the product constantly flow to), the profile for the product should have high microbial count for the very first product out and the count decreases over time (unless gross contamination or the equipment swap being question is used for storage or the equipment being question is pre-storage pipe or line)

Should you be confident on the above the you may want to have your chemicals be sampled for micro and check the swabbing practices.

1. Have one experience before but on handswab that we are getting high APC after hand swab. We requested parallel check with the supplier and we outsource one and the hand sanitizer chemical have TNTC count on all 3 tests. We immediately replaced to alcohol as alternative hand sanitizer.

2. Sampling can very well impact results. Is it sampled wet? Is it sampled dry? Have you sampled finishing the required contact time? Sampled the same sampling point? Are the sampling tools used fit for the environment or product?

3.Lastly, it could also be the cleaning techniques are the one causing the high micro, have you observed the cleaning techniques? Sampling results are always a lagging indicator.  We can take 10, 100 or 1000 samples but if cleaning techniques were not observed, we will just have to wait for the results assuming cleaning follows all parameters.

IMEX of micro. testing/assessment, the first requirement due the occurrence of "unusual" results is to determine -

(1) Were the samples representative of the actual situation ?

(2) Were the results accurate/precise ? eg -

https://byjus.com/ph...on-measurement/

If Yes/Yes then  -

(3) Does an appropriate Specification exist ?

If Yes >

(4) Are the deviations observed significant with respect to the Specification ? (May also involve Trend Analysis)

If Yes >

(5) Look for possible causes.

Unfortunately a "No" frequently pops up before reaching (5).

At the moment I suggest evaluation to be in the (1,2) domain, ie insufficient data.

Hi Charles,

 

Thanks for your reply.

 

The swabs were taken from a piece of stainless steel equipment (non-food contact) by using sponges and sending to external lab. We sent swabs of the same spots before and after cleaning with detergent (2-butoxy-ethanol, potassium hydroxide, tetrasodium EDTA) and rinsing. 

 

Let me know if you still need more context.

Hi Gelato Quality Specialist,

Are you rinsing with just water? and if so have you checked the water?

Kind regards,

Tony