5 replies to this topic

[TomLovesStarch]

Hello,

 

I wan wondering if anyone could give a bit of guidance on using ATP swabs to validate our cleaning regime.

 

The factory is low risk, producing microbiologically stable products (largely oil based). Every batch is sent for a micro screen before distribution and they are normally all well within spec. The factory is BRC Grade A.

 

Currently, we take swabs from zones 1, 2 and 3 in production areas every 6 months, to validate the cleaning procedures (ie check that the cleaning SOPs in the factory are sufficient to keep any bugs under control.) 

 

Swabs are done for TVC, enteros, e coli, yeasts and moulds, and Salmonella

limits are :

Max 1000 cfu/sq cm TVC  

Max 10 cfu/sq cm enteros and e coli

Max 100 cfu/sq cm Y&M

Absence of Salmonella

 

I was looking at ATP because it would be cheaper and faster (currently a swab costs about £10 and takes 5 days for results) - on the last environmental sampling operation, there were quite a few areas that were well out of spec (mostly on TVC and/or yeasts) - which indicates that the cleaning SOPs need updating, (assuming the SOPs are being followed) it seems that getting an ATP kit would allow us to take many more samples, get a better baseline, so that we can identify what effect any new cleaning procedures have / identify any parts of equipment that are being missed.

 

I was wondering if by replacing the micro swabs with ATP swabs would I  be straying into verification of the cleaning rather than validating the procedure... would an auditor be OK with using ATP for enviromental sampling? 

 

Also, I've read that ATP correlates with bacterial presence, because it identifies cells... but if I've understood correctly a high ATP could mean high bacterial load, but a low ATP reading absolutely means low bacterial load...? 

 

Thanks for your help 

 

Tom  

 

[Snookie]

 A solid environmental program usually has both.  ATP allows you to verify on the spot the adequacy of cleaning.  This is especially important on food contact surfaces.  While micro studies are important for verifying the absence of pathogens. 

 

ATP only tells you that cells are present.  They could be plant, human, or bacteria, but something is there, which is their value, if something is there and it is a food contact area--then re-clean.  Micro swabs are useful for drains, floors other locations to verify that pathogens are not present.  Generally speaking the plants I have been at we did small amounts frequently, depending on the product. 

[RG3]

Hello &  TomLovesStarch

 

I 100% agree with Snookie. I would love to share my validation study on this but it is proprietary information. What I can tell you is that you're not looking at apples versus apples. Bioluminescence (which detects the amount of Adenosine Triphosphate, or ATP present) can be used to measure the amount of organic material contaminating a surface. In general terms, it is a measurement of filth. One disadvantage to this technique is that it does not easily distinguish between microbial, human and plant ATP. However, bioluminescence delivers real-time results within seconds after testing the sample site, so sanitation workers can immediately react to and correct a potential unsanitary condition. Your environmentals would be using a specific medium such as an enrichment broth to determine if a specific bacteria is present.

 

I have gotten a high ATP count using both a Hygiene ATP machine and Charm ATP machine and then did a 3M Quick Swab and my results would be <10 cfu/g for APC, E.coli/Coliform, Y&M, Ent. You will always get high counts on your Zone 3's but you won't know what type of contamination you have without a letheen broth or some other kind of enrichment. 

[MWidra]

We have a low-risk product that is tested before release for all the major pathogens.  I perform weekly ATP testing on the important areas with increased areas monthly.  I started this in December, and it has proven very useful in identifying problems with cleaning.  Our test protocol requires that a surface be re-cleaned and re-tested immediately if it is above a certain threshold.

 

But it is not a microbiological surveillance program.  We don't use one because we test product samples, our product is low moisture, and used as an ingredient in foods that will be cooked.  So you need to determine if you want to check for cleaning (ATP only), or if you need to monitor pathogens.

 

It is cool to swab a worker's hand and show that he needs to wash them or change gloves.  I've actually found that the worker who washes his hands frequently gets much lower readings than the one who wears gloves and does not change often enough (something we remedied.)  It is a great snapshot of how clean your building is.

 

Martha

[Charles.C]

Dear TomLovesStarch,

 

FWIW, assuming yr micro. limits are subsequent to cleaning/sanitizing, a few of the maxima are of substantial "Generosity".

 

hopefully most of yr results for TVC are well within the limit.

 

Also, I've read that ATP correlates with bacterial presence, because it identifies cells... but if I've understood correctly a high ATP could mean high bacterial load, but a low ATP reading absolutely means low bacterial load...?

 

2 fundamental  difficulties are that (a) sometimes there is a correlation, eg linear, between ATP and TVC, other times not, reason often, i think, unknown, (b) afaik the atp contribution from bacteria is typically  low - very low on the ATP scale. The consequence is that as per above posts, it is normally used as a cleaning evaluation, not a micro.one, although some people have validated correlations for their specific systems. In general, a high or low ATP may/may not correlate to the TVC level.

 

Rgds / Charles.C

[TomLovesStarch]

Thanks for your help guys,

 

It's given me some things to think about... I'm sure I'll be back soon :)

 

Regards

 

Tom